JPH11299084A - Overcurrent protection device and power receiving equipment equipped with overcurrent protection device - Google Patents

Abstract

(57) [Problem] To prevent an upper circuit breaker from being shut off before a lower circuit breaker is shut off even if there is an individual difference between each overcurrent relay and each current detector, This enhances the coordination of each circuit breaker. SOLUTION: Of the current detectors 6, 10 and 15 provided in each system by an overcurrent protection device 17, the values of the currents detected by the lower current detectors 10 and 15 are added to lower the currents. After calculating the side total current value, when the lower side total current value matches the current value detected by the upper side current detector 5, a cutoff inhibition command is generated and the contact 18 is opened. State so that the upper circuit breaker 4 is not inadvertently shut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overcurrent protection device with improved coordination when performing overcurrent protection coordination of a system, and a power receiving facility equipped with the overcurrent protection device.

[0002]

2. Description of the Related Art In a power receiving facility such as a building, when distributing received power to each system, an overcurrent relay is arranged for each system to protect each system.

FIG. 11 is a block diagram showing an example of a power receiving facility in which an overcurrent relay is arranged for each system.

[0004] A power receiving equipment 151 shown in FIG. 1 includes a power receiving end 152 for receiving power supplied via a transmission line or the like,
The circuit breaker 1 is connected to the power receiving end 152 via an electric wire 153 and cuts off passage of current when a cutoff command is input.
54 and an electric wire 15 having one end connected to the circuit breaker 154.
5, a current detector 156 for detecting the value of the current flowing through the current detector 5, and the value of the current detection signal output from the current detector 156 becomes larger than a preset value. When an interrupt is issued, an overcurrent relay 157 that generates a shutoff command to cause the breaker 154 to be in an interrupted state and prevents an excessive current from flowing through the breaker 154, and one end is connected to the other end of the electric wire 155, A circuit breaker 158 that blocks passage of current when a cutoff command is input, an electric wire 159 having one end connected to the other end of the circuit breaker 158 and the other end connected to a power device (not shown); A current detector 160 for detecting the value of the current flowing through the electric wire 159
And

[0005] Further, the power receiving equipment 151 is in a state in which the value of the current detection signal output from the current detector 160 is larger than a preset value. Generates a command and causes the circuit breaker 15
8 is turned off, an overcurrent relay 161 for preventing an excessive current from flowing through the circuit breaker 158, and one end of the electric wire 1
55, one end of which is connected to the wire 16
A breaker 163 connected to the other end of the second circuit breaker 163 for blocking the passage of current when a cutoff command is input;
Is connected to the other end, and the other end is a power device (not shown)
, A current detector 165 for detecting a value of a current flowing through the wire 164, and a state where the value of a current detection signal output from the current detector 165 is larger than a preset value. When this state has continued for a predetermined time or more, a shutoff command is generated to
And an overcurrent relay 166 for preventing an excessive current from flowing through the circuit breaker 163.

In the power receiving equipment having the above configuration, the power receiving terminal 15
2 is guided along a route of an electric wire 153 → a circuit breaker 154 → an electric wire 155, and is branched on the electric wire 155, and one of the power devices is divided into one power device by a route of an electric wire 155 → a circuit breaker 158 → an electric wire 159. And the other is supplied to other power equipment through a route of the electric wire 162 → the circuit breaker 163 → the electric wire 164. At that time, each current detector 156,
160, 165 each electric wire 155, 159, 164
And the overcurrent relays 157, 161 and 166 enter a state in which the value of each current is larger than a preset current value (rated current value), and this state continues for a predetermined time or more. It is determined whether or not the current larger than the rated current value
When flowing, the overcurrent relays 157, 161, 166
, And a cutoff command is generated to set the corresponding breaker in a cutoff state so that excessive current does not flow downstream from the breaker.

[0007]

However, in such a power receiving facility 151, each of the current detectors 156, 160, 1
65, the circuit breakers 154, 158, and 163 are independently operated based on the detection result. Therefore, each overcurrent relay 157, 161 is provided for each system. , 166, each current detector 156, 160, 165, each breaker 154, 158,
The value of the current flowing through each system must be adjusted by adjusting the setting condition of 163.

However, each of the overcurrent relays 157, 1
61, 166, each current detector 156, 16
0, 165 and the overcurrent relays 157, 161, 16 even if the setting conditions of the circuit breakers 154, 158, 163 are adjusted.
6 and the individual differences between the current detectors 156, 160, 165, etc., when an overcurrent occurs in any of the systems, the current cannot be cut off as set, There has been a problem that the phenomenon cannot be completely eliminated.

In view of the above circumstances, the present invention is directed to claim 1, wherein even if there is an individual difference between each overcurrent relay, each current detector, and the like, when an overcurrent occurs in any of the respective systems, It is an object of the present invention to provide an overcurrent protection device that can shut off a lower circuit breaker before one of the circuit breakers is shut off, thereby improving the coordination of the respective circuit breakers.

According to a second aspect of the present invention, there is provided an overcurrent protection device capable of performing overcurrent protection for each system without using an overcurrent relay on the lower side, thereby reducing the system construction cost. It is intended to be.

According to a third aspect of the present invention, there is provided an overcurrent protection device capable of performing overcurrent protection of each system without using any overcurrent relay, thereby further reducing the system construction cost. It is intended to be.

A fourth object of the present invention is to provide an overcurrent protection device capable of performing overcurrent protection of each system without using a higher-level overcurrent relay.

According to a fifth aspect of the present invention, even if there is an individual difference between each overcurrent relay and each current detector, when an overcurrent occurs in any of the respective systems, before an upper circuit breaker is shut off. ,
The lower circuit breaker can be shut down, and even if the lower circuit breaker cannot be shut down by this, it can be shut down by an overcurrent relay, which allows the coordination of each breaker and the system An object of the present invention is to provide a power receiving facility that can be compatible with safety.

[0014]

According to a first aspect of the present invention, there is provided a power receiving apparatus for distributing received power to a plurality of systems and supplying the power to power devices provided in each system. An overcurrent protection device in a facility, wherein a sum of lower-side current values obtained by respective current detectors disposed on a lower side and an upper-side current value obtained by a current detector disposed on an upper side are determined. The upper-side cut-off condition determining unit that compares the upper-side current value with the upper-side current value is determined by the upper-side cut-off condition determiner to determine whether or not they are in a predetermined correspondence relationship. When it is determined that there is, a shutoff inhibition control unit that inhibits the upper circuit breaker from being interrupted is provided.

According to a second aspect of the present invention, there is provided an overcurrent protection device in a power receiving facility for distributing received power to a plurality of systems and supplying the power to power devices provided in each system, wherein each of the currents disposed on a lower side is provided. In a state where the sum of the lower-side current values obtained by the detectors and the upper-side current values obtained by the current detectors arranged on the upper side have a predetermined correspondence relationship, one of the respective lower-side current values is A lower cut-off condition determining unit for determining whether the current value exceeds a set current value, and when the lower cut-off condition determining unit determines that any of the lower current values exceeds the set current value. And a cutoff control unit that cuts off the lower circuit breaker that is overcurrent.

According to a third aspect of the present invention, there is provided an overcurrent protection device in a power receiving facility for distributing received power to a plurality of systems and supplying power to power devices provided in the respective systems, wherein each of the current In a state where the sum of the lower-side current values obtained by the detectors and the upper-side current values obtained by the current detectors arranged on the upper side have a predetermined correspondence relationship, one of the respective lower-side current values is A lower-side cut-off condition determining unit that determines whether each lower-side set current value is exceeded; and one of the lower-side current values exceeds the lower-side set current value by the lower-side cut-off condition determination unit. When it is determined that the lower circuit breaker is overcurrent, the lower circuit breaker control section that cuts off the lower circuit breaker, and the upper current value obtained by the current detector arranged on the upper To determine whether the upper limit has been exceeded And an upper interrupter that interrupts an overcurrent upper interrupter when the upper interrupt condition determining unit determines that the upper current value exceeds the upper set current value. And a control unit.

According to a fourth aspect of the present invention, there is provided an overcurrent protection device in a power receiving facility for distributing received power to a plurality of systems and supplying the power to power devices provided in the respective systems, wherein each of the current In a state where the sum of the lower-side current values obtained by the detectors and the upper-side current values obtained by the current detectors arranged on the upper side have a predetermined correspondence relationship, one of the respective lower-side current values is A lower-side cut-off condition determining unit that determines whether each lower-side set current value is exceeded; and one of the lower-side current values exceeds the lower-side set current value by the lower-side cut-off condition determination unit. When it is determined that, the lower-side cutoff control unit that cuts off the lower-side breaker that is overcurrent, the sum of the lower-side current values obtained by each current detector arranged on the lower side and the upper-side And the higher-side current value obtained by the current detector A high-order cut-off condition determining unit that determines whether a high-order current value obtained by a current detector arranged on a high-order side exceeds a high-order set current value in a state of a fixed correspondence; An upper-side cutoff control unit that shuts off an overcurrent upper-side circuit breaker when the upper-side current value exceeds the upper-side set current value by the upper-side cutoff condition determination unit. It is characterized by that.

In the power receiving equipment according to the fifth aspect, the second aspect
When it is determined that the lower current value obtained by the overcurrent protection device described above and each current detector arranged on the lower side exceeds the set current value for a predetermined time or more, And a plurality of overcurrent relays for interrupting the lower circuit breaker which is a current.

In the configuration of the first aspect, the upper-side cut-off condition judging section uses the sum of the lower-side current values obtained by the respective current detectors arranged on the lower side and the current detector arranged on the upper side. The obtained upper current values are compared with each other to determine whether or not they have a predetermined correspondence. When the upper-side cut-off condition determining unit determines that the sum of the lower-side current values and the upper-side current value are in a predetermined correspondence relationship, the cut-off inhibition control unit shuts off the upper-side circuit breaker. Prohibited. With this, even if there is an individual difference between each overcurrent relay and each current detector, etc., when an overcurrent occurs in any of the systems, before the upper circuit breaker is shut off,
The lower circuit breaker is cut off to enhance the coordination of each circuit breaker.

In the configuration of claim 2, the lower-side cut-off condition judging section determines the sum of the lower-side current values obtained by the respective current detectors arranged on the lower side and the current detectors arranged on the upper side. When there is a predetermined correspondence with the obtained upper current value, it is determined whether or not any of the lower current values exceeds the set current value. When the lower-side cut-off condition determining unit determines that any of the lower-side current values exceeds the set current value, the cut-off control unit cuts off the overcurrent lower-side circuit breaker. . As a result, overcurrent protection of each system is performed without using an overcurrent relay on the lower side, thereby reducing the system construction cost.When an overcurrent occurs in any of the systems, each overcurrent is protected. Even if there is an individual difference between the current relays and the current detectors, the lower circuit breaker is cut off before the upper circuit breaker is cut off, thereby improving the coordination of the circuit breakers.

In the configuration of claim 3, the lower-side cut-off condition judging section determines the total sum of the lower-side current values obtained by the respective current detectors disposed on the lower side and the current value obtained by the current detector disposed on the upper side. When the obtained upper-side current value has a predetermined correspondence, it is determined whether or not any of the lower-side current values exceeds each lower-side set current value. When the lower-side cut-off condition determining unit determines that any of the lower-side current values exceeds the lower-side set current value, the lower-side cut-off control unit sets the lower-side overcurrent to be an overcurrent. The circuit breaker is shut off, and the upper-side cut-off condition determining unit determines whether the upper-side current value obtained by the current detector arranged on the upper side exceeds the upper-side set current value. When the cutoff condition determining unit determines that the upper current value exceeds the upper set current value, the upper cutoff control unit cuts off the overcurrent upper circuit breaker. As a result, overcurrent protection of each system can be performed without using any overcurrent relay, thereby further reducing the system construction cost. Even if there is an individual difference between the detectors and the like, the lower circuit breaker is shut off before the upper circuit breaker is shut off, and the coordination of each circuit breaker is improved.

In the configuration of the fourth aspect, the lower-side cut-off condition judging section determines the sum of the lower-side current values obtained by the respective current detectors arranged on the lower side and the sum of the lower-side current values obtained by the current detectors arranged on the upper side. When the obtained upper-side current value has a predetermined correspondence, it is determined whether or not any of the lower-side current values exceeds each lower-side set current value. When the lower-side cut-off condition determining unit determines that any of the lower-side current values exceeds the lower-side set current value, the lower-side cut-off control unit sets the lower-side overcurrent to be an overcurrent. The circuit breaker is shut off, and the sum of the lower current values obtained by each current detector arranged on the lower side and the upper current value obtained by the current detector arranged on the upper side correspond to a predetermined correspondence. When there is a relationship, the upper-side cut-off condition determination unit determines whether the upper-side current value obtained by the current detector arranged on the upper side exceeds the upper-side set current value. When the upper-side cut-off condition determining section determines that the upper-side current value exceeds the upper-side set current value, the upper-side cutoff control section cuts off the overcurrent upper-side breaker. I do. As a result, overcurrent protection of each system is performed without using an overcurrent relay on the upper side, thereby reducing the system construction cost.When an overcurrent occurs in any of the systems, each overcurrent is protected. Even if there is an individual difference between the current relays and the current detectors, the lower circuit breaker is cut off before the upper circuit breaker is cut off, thereby improving the coordination of the circuit breakers.

In the configuration of the fifth aspect, the lower-side cut-off condition judging section obtains the sum of the lower-side current value obtained by each of the current detectors arranged on the lower side and the current detector arranged on the upper side. When the set upper-side current value is in a predetermined correspondence relationship, does any of the lower-side current values exceed a set current value smaller than the set current value of each breaker provided on the upper side? Determine whether When the lower-side cut-off condition determining unit determines that any of the lower-side current values exceeds the set current value, the cut-off control unit includes:
In addition to interrupting the lower-side circuit breaker that is overcurrent, in a plurality of overcurrent relays, each lower-side current value obtained by each current detector disposed in the lower side is equal to or longer than a predetermined time. When it is determined that the current exceeds the set current value, the lower circuit breaker that is overcurrent is shut off. With this, even if there is an individual difference between each overcurrent relay and each current detector, when an overcurrent occurs in any of the systems, the lower circuit breaker is turned off before the upper circuit breaker is broken. In addition to shutting down the circuit breaker, even if the lower circuit breaker cannot be shut down by this, the lower circuit breaker is shut down by an overcurrent relay, thereby achieving compatibility between each circuit breaker and system safety. Let it.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS << Description of First Embodiment >> FIG.
1 is a schematic configuration diagram showing a first embodiment corresponding to claim 1 among power receiving equipment to which an overcurrent protection device according to the present invention is applied.

The power receiving equipment 1 shown in FIG. 1 includes a power receiving end 2 for receiving power supplied through a transmission line or the like, and a power receiving end 2.
A circuit breaker 4 is connected via a wire 3 connected to the circuit breaker 4 to block the passage of current when a cutoff command is input; a wire 5 having one end connected to the other end of the circuit breaker 4; Current detector 6 for detecting the value of the current flowing through the current detector 6, and the value of the current detection signal output from the current detector 6 becomes larger than a preset value, and this state continues for a predetermined time or more. A breaker command is generated, the breaker 4 is turned off, an overcurrent relay 7 for preventing an excessive current from flowing through the breaker 4, and one end is connected to the other end of the electric wire 5. When a command is input, a circuit breaker 8 that blocks the passage of current, an electric wire 9 having one end connected to the other end of the circuit breaker 8 and the other end connected to a power device (not shown), A current detector 10 for detecting a value of a current flowing through the electric wire 9
When the value of the current detection signal output from the current detector 10 is larger than a preset value, and when this state has continued for a predetermined time or more, a cutoff command is generated, 8 is provided with an overcurrent relay 11 for shutting off the circuit 8 and preventing an excessive current from flowing through the circuit breaker 8.

Further, the power receiving equipment 1 has an electric wire 12 having one end connected to the middle of the electric wire 5 and one end connected to the other end of the electric wire 12, and shuts off the passage of current when a cutoff command is input. A circuit 13, an electric wire 14 having one end connected to the other end of the circuit breaker 13 and the other end connected to a power device (not shown), and a current detector 15 for detecting a value of a current flowing through the electric wire 14. When the value of the current detection signal output from the current detector 15 is larger than a preset value, and this state continues for a predetermined time or more, the overcurrent relay 16 that generates the cutoff command is output. Is determined based on the current detection signals output from the current detectors 6, 10, and 15 to determine whether or not the interrupting condition of the circuit breaker 4 arranged on the upper side is satisfied, and the interrupting condition is not satisfied. Generates a shutdown prohibition command when When the cut-off prohibition command is output from the over-current protection device 17 and the cut-off prohibition command is output from the over-current protection device 17, the cut-off command output from the over-current relay 7 is cut off and cut off. And a contact 18 for preventing the container 4 from being interrupted.

In this case, the overcurrent protection device 17 takes in the current detection signals output from the current detectors 6, 10, and 15 and determines whether or not the inrush current has converged.
When the inrush current converges, each of the lower current detectors 1
The current values indicated by the current detection signals output from 0 and 15 are added to calculate the lower total current value, and the lower total current value and the current output from the upper current detector 6 are calculated. An arithmetic circuit 19 that compares the current value (upper-side current value) indicated by the detection signal and determines whether or not they match each other. This arithmetic circuit 19 calculates the lower-side total current value and the upper-side current value. And an output circuit for generating a cut-off prohibition command when it is determined that they coincide with each other and opening the contact.

In the power receiving equipment 1 having the above-described configuration, the power received at the power receiving end 2 is guided along the route of the electric wire 3 → the circuit breaker 4 → the electric wire 5, and is branched on the electric wire 5, and one of them is connected to the electric wire 5 The power is supplied to one power device through the path of the circuit breaker 8 → the electric wire 9, and the other is supplied to the other power device through the path of the electric wire 12 → the circuit breaker 13 → the electric wire 14. At this time, the current detectors 6, 10, and 15 detect the values of the currents flowing through the electric wires 5, 9, and 14, respectively, and the respective current values become larger than a preset current value. When the state has continued for a predetermined time or more, each of the overcurrent relays 7, 1
This is detected by 1, 16 and a shutoff command is generated,
The corresponding circuit breaker is switched off so that no excessive current flows downstream from this circuit breaker.

In parallel with this operation, as shown in the flow chart of FIG. 2, the current detection signals output from the current detectors 6, 10, 15 provided in the respective systems by the overcurrent protection device 17 are output. Take it in and check whether the inrush current of each system has converged. As a result of the check, when the inrush current of each system has converged (step ST
1), each of the current detectors 10 and 1 provided in the lower system
After calculating the lower total current value by adding the current values detected in step 5, the lower total current value is compared with the current value detected by the current detector 6 provided in the upper system. Are checked to see if they match, and if they match (step ST2), a cutoff prohibition command is generated and the contact 1
8 is opened (step ST3).

As a result, the lower overcurrent relay 1
Even if a cutoff command is generated by the overcurrent relay 7 on the upper side before the cutoff command is generated by the switches 1 and 16, the cutoff command is cut off by the contact 18 and the circuit breaker 4 on the upper side is cut off. To prevent

As described above, in the first embodiment,
Of the current detectors 6, 10, and 15 provided in each system by the overcurrent protection device 17, the lower current detectors 1
After adding the current values detected at 0 and 15 to calculate the lower total current value, the lower total current value matches the current value detected by the upper current detector 5. In this case, a cutoff prohibition command is generated and the contact 18 is opened to prevent the upper breaker 4 from being inadvertently cut off, so that each of the overcurrent relays 7, 11, 16 and each current Even if there is an individual difference between the detectors 6, 10, 15 and the like, the upper circuit breaker 4 before the lower circuit breakers 8, 13 are cut off.
Can be prevented from being interrupted, whereby each circuit breaker 4,
8, 13 coordination can be enhanced.

<< Description of Second Embodiment >> FIG. 3 is a schematic configuration diagram showing a second embodiment corresponding to claim 2 of the power receiving equipment to which the overcurrent protection device according to the present invention is applied. is there.

The power receiving equipment 25 shown in FIG. 3 has a power receiving end 26 for receiving power supplied via a power transmission line or the like, and is connected to the power receiving end 26 via an electric wire 27 when a cutoff command is input. A circuit breaker 28 for blocking the passage of current, a wire 29 having one end connected to the other end of the circuit breaker 28, a current detector 30 for detecting a value of a current flowing through the wire 29,
When the value of the current detection signal output from the current detector 30 is larger than a preset value, and this state has continued for a certain period of time or more, a cutoff command is generated and the breaker 28 is turned on. An overcurrent relay 31 for shutting off and preventing an excessive current from flowing through the circuit breaker 28; and an interrupter for connecting one end to the other end of the electric wire 29 and interrupting the passage of current when a shutoff command is input. It has a switch 32 and an electric wire 33 having one end connected to the other end of the circuit breaker 32 and the other end connected to a power device (not shown).

Further, the power receiving equipment 25 includes a current detector 34 for detecting a value of a current flowing through the electric wire 33, an electric wire 35 having one end connected to the middle of the electric wire 29, and an electric wire 35
And a breaker 36 that cuts off the passage of current when a cutoff command is input, and one end is connected to the other end of the breaker 36 and the other end is connected to a power device (not shown). An electric wire 37 to be connected; a current detector 38 for detecting a value of a current flowing through the electric wire 37;
Based on the value of the current detection signal output from 8, it is determined whether or not the interrupting conditions of the circuit breakers 32 and 36 arranged on the lower side are satisfied. When the interrupting conditions are satisfied, a shutoff command is generated. And an overcurrent protection device 39 for shutting off one of the circuit breakers 32 and 36 for which the interrupting condition is satisfied.

In this case, the overcurrent protection device 39 takes in the current detection signals output from the current detectors 30, 34, and 38 and determines whether or not the inrush current has converged. The current values indicated by the current detection signals output from the lower current detectors 34 and 38 are added to calculate the lower total current value. Comparing the lower total current value with the current value (upper current value) indicated by the current detection signal output from the upper current detector 30 to determine whether or not they match; When it is determined that the upper current value matches the lower total current value by this determination processing, each of the lower circuit breakers 32 and 36 is determined.
Arithmetic circuit 40 for performing processing such as overcurrent determination processing for determining whether a current exceeding the rated current value is flowing through
And an output circuit 41 that generates a shutoff command when there is a circuit breaker determined to be an overcurrent by the arithmetic circuit 40 and shuts off the overcurrent circuit breaker.

In the power receiving equipment 25 having the above configuration, the power receiving end 2
The electric power received in 6 is converted to electric wire 27 → circuit breaker 28 → electric wire 29
While branching on the electric wire 29, one of them is supplied to one power device via the electric wire 29 → the circuit breaker 32 → the electric wire 33, and the other is supplied to the electric wire 35 → the circuit breaker 36 → the electric wire 37. Supply to other power equipment through a different route. At this time, the current detectors 30, 34, and 38 detect the values of the currents flowing through the wires 29, 33, and 37, respectively, and the current value on the upper side becomes larger than a preset current value. When this state continues for a certain period of time or more, this is detected by the overcurrent relay 31,
A shutoff command is generated, and the upper circuit breaker 28 is turned off to prevent an excessive current from flowing from the circuit breaker 28 to the downstream side.

In parallel with this operation, as shown in the flowchart of FIG. 4, the current detection signals output from the current detectors 30, 34, and 38 provided in the respective systems by the overcurrent protection device 39 are output. It is checked whether or not the inrush current of each system has converged, and when the inrush current of each system has converged (step ST5), detection is performed by each of the current detectors 34 and 38 provided in the lower system. After adding the calculated current values to calculate the lower total current value, the lower total current value is compared with the current detector 3 provided in the upper system.
It is checked whether the current value detected at 0 matches the current value, and when these values match (step ST6),
It is determined whether the current value detected by each of the lower current detectors 34 and 38 exceeds the rated current value of each of the circuit breakers 32 and 36.

When one of the current values flowing through each of the circuit breakers 32 and 36 exceeds the rated current value (step ST7), the overcurrent protection device 39 generates a cutoff command to generate an overcurrent. Is shut off (step ST8).

As described above, in the second embodiment,
Of the current detectors 30, 34, 38, the values of the currents detected by the lower current detectors 34, 38 are added to calculate a lower total current value. In a state in which the current value detected by the upper current detector 30 matches the current value, one of the current values detected by the lower current detectors 34 and 38 exceeds the rated current value. At this time, since this is detected and the breaker in the overcurrent state is cut off, the current detector 3 provided in each system is
When an excessive current is detected by any of 0, 34, and 38, the overcurrent protection device 39 detects the excessive current before the upper circuit breaker 28 is cut off, and the overcurrent state is set. The lower circuit breaker 32 or circuit breaker 36 on the lower side can be cut off first.

Thus, even if there is an individual difference between the overcurrent relay 31 and each of the current detectors 30, 34 and 38, the lower circuit breaker 32,
By shutting off 36, the coordination of the respective breakers 28, 32, 36 can be enhanced.

Further, in the second embodiment, since the overcurrent protection device 39 has the function of the lower overcurrent relay, the lower circuit breakers 32 and 36 are provided with overcurrent relays and the like. The connection work, the work for setting the operation current value of each overcurrent relay, and the like can be omitted, thereby improving the economy of the entire system.

<< Description of Third Embodiment >> FIG. 5 shows a power receiving facility according to the present invention.
It is a schematic structure figure showing an embodiment.

The power receiving equipment 45 shown in this figure has a power receiving end 46 for receiving power supplied via a power transmission line or the like, and is connected to the power receiving end 46 via an electric wire 47 when a cutoff command is input. A circuit breaker 48 for blocking the passage of current, a wire 49 having one end connected to the other end of the breaker 48, a current detector 50 for detecting a value of a current flowing through the wire 49,
When the value of the current detection signal output from the current detector 50 is larger than a preset value, and when this state has continued for a certain period of time or more, a cutoff command is generated and the circuit breaker 48 is turned on. An overcurrent relay 51 that is in a cutoff state to prevent an excessive current from flowing through the circuit breaker 48, and a cutoff that has one end connected to the other end of the electric wire 49 and cuts off the passage of current when a cutoff command is input. And a wire 53 having one end connected to the other end of the circuit breaker 52 and the other end connected to a power device (not shown), and a current detector 54 for detecting a value of a current flowing through the wire 53. And the current detector 5
When the value of the current detection signal output from 4 is larger than a preset value and this state has continued for a certain period of time or more, a shutoff command is generated, and the circuit breaker 52 is turned off. An overcurrent relay 55 for preventing an excessive current from flowing through the circuit breaker 52 is provided.

Further, one end of the power receiving equipment 45 has an electric wire 49.
, One end is connected to the other end of the electric wire 56, and a breaker 57 that cuts off the passage of current when a cutoff command is input, and one end is connected to the other end of the breaker 57. An electric wire 58 having the other end connected to a power device (not shown), a current detector 59 for detecting a value of a current flowing through the electric wire 58, and a current detection signal output from the current detector 59 Is greater than the preset value, and when this state has continued for a certain period of time,
An overcurrent relay 60 for generating a cutoff command to put the breaker 57 in a cutoff state so that an excessive current does not flow through the breaker 57, and a current detection output from each of the current detectors 50, 54, and 59. Based on the value of the signal, it is determined whether or not the interrupting conditions of the circuit breakers 52 and 57 disposed on the lower side are satisfied. When the interrupting conditions are satisfied, a shutoff command is generated,
An overcurrent protection device 61 is provided for interrupting one of the circuit breakers 52 and 57 for which the interruption condition is satisfied.

In this case, the overcurrent protection device 61 takes in the current detection signals output from the respective current detectors 50, 54, 59 and determines whether or not the inrush current has converged. Is calculated, the current values indicated by the current detection signals output from the lower current detectors 54 and 59 are added to calculate a lower total current value. Comparing the lower total current value with the current value (upper current value) indicated by the current detection signal output from the upper current detector 50, and judging whether or not they match. When it is determined that the upper current value matches the lower total current value by this determination processing, each of the lower circuit breakers 52 and 57 is determined.
Among them, an operation for performing a process such as an overcurrent determination process for determining whether there is a circuit breaker in which a current exceeding a rated current value (a current value smaller than a rated current value of the upper-side overcurrent relay 51) flows. A circuit 62 and an output circuit that, when the arithmetic circuit 62 determines that the lower circuit breakers 52 and 57 are overcurrent, generates a disconnection command and disconnects the overcurrent circuit breaker. 63.

In the power receiving equipment 45 having the above-described configuration, the power received at the power receiving end 46 is guided along the route of the electric wire 47 → the circuit breaker 48 → the electric wire 49, and is branched on the electric wire 49. → Circuit breaker 52 → Supply power to one power device via route 53, and the other to wire 56 →
When the power is supplied to other power devices through the path from the circuit breaker 57 to the electric wire 58, the current detectors 50, 54, and 59 detect the values of the currents flowing through the electric wires 49, 53, and 58, respectively. When the state becomes larger than a preset current value and this state continues for a certain period of time or more, this is detected by each of the overcurrent relays 51, 55, and 60, a cutoff command is generated, and a corresponding cutoff is generated. The circuit breaker is shut off so that no excessive current flows downstream from the circuit breaker.

In parallel with this operation, as shown in the flowchart of FIG. 6, each current detection signal output from each current detector 50, 54, 59 provided in each system by the overcurrent protection device 61 is output. It is checked whether the inrush current of each system has converged, and when the inrush current of each system has converged (step ST10), detection is performed by each of the current detectors 54 and 59 provided in the lower system. After adding the calculated current values to calculate the lower total current value, the lower total current value matches the current value detected by the current detector 50 provided in the upper system. It is checked whether they match (step ST1).
1) It is determined whether the current value detected by each of the current detectors 54 and 59 exceeds the rated current value of each of the circuit breakers 52 and 57.

When a current having a current value exceeding the rated current value is flowing through one of the circuit breakers 52 and 57 (step ST12), the overcurrent protection device 61 generates a cutoff command, and The circuit breaker in which the current is flowing is cut off (step ST13).

As described above, in the third embodiment,
Of the current detectors 50, 54, 59, the current values detected by the lower current detectors 54, 59 are added to calculate a lower total current value. In a state where the current value detected by the upper-side current detector 50 matches the current value detected by the lower-side current detectors 54 and 59, one of the current values detected by the When the rated current value (current value smaller than the rated current value of the overcurrent relay 51 on the upper side) is exceeded, this is detected and the circuit breaker in the overcurrent state is cut off. ,
When an excessive current is detected by any of the current detectors 50, 54, 59 provided in each system, the overcurrent protection device 61 detects this before the upper circuit breaker 48 is cut off. Thus, the lower circuit breaker in the overcurrent state can be cut off first.

Thus, each of the overcurrent relays 51, 5
Even if there is an individual difference between the circuit breakers 5 and 60 and the current detectors 50, 54 and 59, the lower circuit breakers 52 and 57 are cut off before the upper circuit breaker 48 is cut off. Vessels 48, 5
The coordination of 2, 57 can be enhanced.

In the third embodiment, the lower circuit breakers 52 and 57 cannot be shut off before the upper circuit breaker 48 is shut off by the overcurrent protection device 61. Even at times, each of the overcurrent relays 55, 60
Thereby, each circuit breaker 52, 57 can be cut off,
As a result, coordination between the respective circuit breakers 48, 52, 57 and system safety can be compatible.

<< Description of Fourth Embodiment >> FIG. 7 is a schematic configuration diagram showing a fourth embodiment corresponding to claim 3 of the power receiving equipment to which the overcurrent protection device according to the present invention is applied. is there.

The power receiving equipment 70 shown in this figure has a power receiving end 71 for receiving power supplied via a power transmission line or the like, and is connected to the power receiving end 71 via an electric wire 72 when a cutoff command is input. A circuit breaker 73 for blocking the passage of current, a wire 74 having one end connected to the other end of the breaker 73, a current detector 75 for detecting a value of a current flowing through the wire 74,
One end is connected to the other end of the electric wire 74, and when a cutoff command is input, a breaker 76 that blocks the passage of current, one end is connected to the other end of the breaker 76, and the other end is a power device (not shown). (Not shown), a current detector 78 for detecting the value of the current flowing through the wire 77, and one end of the wire 7
7, one end is connected to the other end of the electric wire 79, and a breaker 80 that cuts off the passage of current when a cutoff command is input, and one end is connected to the other end of the breaker 80. An electric wire 81 connected at the other end to a power device (not shown), a current detector 82 for detecting a value of a current flowing through the electric wire 81, and an output from each of the current detectors 75, 78, 82 Based on the value of the detected current detection signal,
It is determined whether or not the cutoff conditions of 3, 76, and 80 are satisfied. When the cutoff conditions are satisfied, a cutoff command is generated,
An overcurrent protection device 83 is provided for interrupting a circuit breaker of which the interruption condition is satisfied among the circuit breakers 73, 76, and 80.

In this case, the overcurrent protection device 83 takes in the current detection signals output from each of the current detectors 75, 78 and 82, and determines whether or not the inrush current has converged. When it is determined that the inrush current has converged by the inrush end determination process, the inrush current is determined by an upper overcurrent determination process that determines whether the upper circuit breaker 73 is in an overcurrent state, and the inrush is determined by the inrush end determination process. When it is determined that the currents have converged, arithmetic processing for adding the respective current values indicated by the current detection signals output from the lower current detectors 78 and 82 to calculate the lower total current value Then, the lower total current value obtained by this arithmetic processing is compared with the current value (upper current value) indicated by the current detection signal output from the upper current detector 75, and they are matched. Whether or not Determination processing for determining, by the determination process, when the upper current value and the lower total current value is determined to match, the lower the breaker 76,8
0, the rated current value (the circuit breaker 73 provided on the upper side)
An arithmetic circuit 84 for performing a process such as an overcurrent determination process for determining whether or not there is a circuit breaker in which a current exceeding the rated current value is smaller than the rated current value.
When there is a circuit breaker determined to be an overcurrent, a break command is generated, and among the breakers 73, 76, and 80,
An output circuit 85 for shutting off the overcurrent circuit breaker.

In the power receiving equipment 70 having the above configuration, the power receiving end 7
The electric power received in step 1 is converted to electric wire 72 → circuit breaker 73 → electric wire 74
While branching on the electric wire 74, one of them is supplied to one power device through the electric wire 74 → the circuit breaker 76 → the electric wire 77, and the other is the electric wire 79 → the circuit breaker 80 → the electric wire 81. Supply to other power equipment through a different route. At that time, as shown in the flow chart of FIG. 8, each of the current detectors 75, 78, 8
2 to check whether the inrush current of each system has converged. When the inrush current of each system has converged (step ST15), the current detection signal provided in the lower system is provided. After adding the current values detected by the current detectors 78 and 82 to calculate the lower total current value, the lower total current value is calculated by the current detector 75 provided in the upper system. It is checked whether or not the detected current values match, and when they match (step ST16), the current values detected by the current detectors 78 and 82 are equal to the rated currents of the circuit breakers 76 and 80. Determine if the value is exceeded.

When a current having a current value exceeding the rated current value flows through one of the circuit breakers 76 and 80 (step ST17), the overcurrent protection device 83 generates a disconnection command and outputs The circuit breaker in which the current is flowing is cut off (step ST18).

In parallel with this operation, when the inrush current of each system has converged, it is checked by the overcurrent protection device 83 whether the value of the current flowing through the upper circuit breaker 73 exceeds the rated current value. If the current flowing through the upper circuit breaker 73 exceeds the rated current value (step ST
19), an interruption command is generated, and the upper circuit breaker 73 is interrupted (step ST20).

As described above, in the fourth embodiment,
Of the current detectors 75, 78, 82, the lower-side total current value is calculated by adding the values of the currents detected by the lower-side current detectors 78, 82, and this lower-side total current value, In a state where the current value detected by the upper current detector 75 matches the current value detected by the upper current detector 75, one of the current values detected by the lower current detectors 78 and 82 exceeds the rated current value. When this is detected, the lower circuit breaker in the overcurrent state is cut off, and when the current value detected by the upper current detector 75 exceeds the rated current value, When an excessive current flows in any of the circuit breakers 73, 76, and 80 provided in each system, this is detected, and the lower circuit breaker 73 is detected. 7
6, 80, and the upper circuit breaker 73 in this order.
3, 76, 80 can be cut off, so that even if there is an individual difference in each of the current detectors 75, 78, 82, etc.
After the lower circuit breakers 76, 80 are shut off, the upper circuit breaker 73 is shut off, so that the coordination of the respective circuit breakers 73, 76, 80 can be enhanced.

In the fourth embodiment, the overcurrent protection device 83 is provided with the function of an overcurrent relay, so that the overcurrent protection of each system can be performed without using any overcurrent relay. This makes it possible to reduce the system construction cost, and to connect an overcurrent relay or the like to each of the circuit breakers 73, 76, and 80, and to set the operating current value of each overcurrent relay. And the like can be omitted, thereby improving the economy of the entire system.

<< Description of Fifth Embodiment >> FIG. 9 is a schematic configuration diagram showing a fifth embodiment corresponding to claim 4 of the power receiving equipment to which the overcurrent protection device according to the present invention is applied. is there.

The power receiving equipment 90 shown in this figure has a power receiving end 91 that receives power supplied via a power transmission line or the like, and is connected to the power receiving end 91 via an electric wire 92, and when a cutoff command is input. A circuit breaker 93 for blocking the passage of current, a wire 94 having one end connected to the other end of the circuit breaker 93, a current detector 95 for detecting a value of a current flowing through the wire 94,
One end is connected to the other end of the electric wire 94, and when a cutoff command is input, a circuit breaker 96 that blocks the passage of current, one end is connected to the other end of the circuit breaker 96, and the other end is a power device (illustrated in FIG. (Not shown), a current detector 98 for detecting a value of a current flowing through the electric wire 97, and a value of a current detection signal output from the current detector 98 being higher than a preset value. When the state becomes large and this state continues for a certain period of time or more, a shutoff command is generated to
And an overcurrent relay 99 for preventing an excessive current from flowing through the circuit breaker 96.

Further, the power receiving equipment 90 includes an electric wire 100 having one end connected in the middle of the electric wire 94 and an electric wire 10 having one end connected to the electric wire 10.
0 is connected to the other end of the circuit breaker 101 and cuts off the passage of current when a cutoff command is input;
Is connected to the other end, and the other end is a power device (not shown)
, A current detector 103 for detecting a value of a current flowing through the wire 102, and a state where the value of a current detection signal output from the current detector 103 is larger than a preset value. When this state continues for a certain period of time or more, a shutoff command is generated and the circuit breaker 10
1 to a cut-off state, and an overcurrent relay 104 for preventing an excessive current from flowing through the circuit breaker 101, and each of the circuit breakers based on the value of the current detection signal output from each of the current detectors 95, 98, 103. It is determined whether or not the cutoff conditions of 93, 96 and 101 are satisfied, and when the cutoff conditions are satisfied,
An overcurrent protection device 105 that generates a shutoff command and shuts off one of the breakers 93, 96, and 101 that meets the shutoff condition is provided.

In this case, the overcurrent protection device 105 takes in the current detection signals output from the current detectors 95, 98, and 103 and determines whether or not the inrush current has converged. When it is determined by the inrush end determination processing that the inrush current has converged, the respective current values indicated by the current detection signals output from the lower current detectors 98 and 103 are added, and the lower total current is calculated. A calculation process for calculating the value, comparing the lower total current value obtained by this calculation process with the current value (upper current value) indicated by the current detection signal output from the upper current detector 95. A judgment process for judging whether or not these coincide with each other. When it is judged by the judgment process that the upper current value and the lower total current value match, each of the lower circuit breakers 96, 101 horse , An overcurrent determination process determines whether there is a circuit breaker that flows current exceeding the rated current value,
When the determination processing is completed, an arithmetic circuit 106 for performing processing such as an upper-side overcurrent determination processing for determining whether or not the upper circuit breaker 93 is in an overcurrent state; When there is a circuit breaker determined to be an overcurrent among the circuits 93, 96, and 101, an output circuit 107 that generates a shutdown command and shuts off the overcurrent circuit breaker is provided.

In the power receiving equipment 90 having the above configuration,
The power received at the power receiving end 91 is converted to electric wire 92 → circuit breaker 93 →
It is guided along the route of the electric wire 94, and is branched on the electric wire 94, and one of them is branched from the electric wire 94 → the circuit breaker 96 → the electric wire 97.
To one power device and the other to electric wire 1
When supplying power to other power devices through the path of 00 → breaker 101 → wire 102, each current detector 95, 98, 103 detects the value of the current flowing through each wire 94, 97, 102, and The value becomes larger than the preset current value, and when this state continues for a certain period of time or more, this is detected by each overcurrent relay 99, 104 on the lower side, and a cutoff command is generated, The corresponding circuit breaker is switched off so that no excessive current flows downstream from this circuit breaker.

In parallel with this operation, as shown in the flowchart of FIG. 10, the current detection signals output from the current detectors 95, 98, and 103 are fetched by the overcurrent protection device 105, and the inrush of each system is started. It is checked whether or not the current has converged, and when the inrush current of each system has converged (step ST20), the value of the current detected by each of the current detectors 98 and 103 provided in the lower system is added. Then, after calculating the lower total current value, it is checked whether the lower total current value matches the current value detected by the current detector 95 provided in the upper system, When they match (step ST21), it is determined whether the current value detected by each of the lower current detectors 98 and 103 exceeds the rated current value of each of the circuit breakers 96 and 101.

When a current having a current value exceeding the rated current value flows through one of the circuit breakers 96 and 101 (step ST22), the overcurrent protection device 105 generates a cutoff command, and The circuit breaker in which the current is flowing is cut off (step ST23).

In parallel with this operation, when the lower total current value matches the current value detected by the current detector 95 provided in the higher system (step ST2).
1), the upper circuit breaker 9 by the overcurrent protection device 105
It is determined whether or not the value of the current flowing through 3 exceeds the rated current value. If the current flowing through the upper circuit breaker 93 exceeds the rated current value (step ST24), a cutoff command is generated. Then, the upper circuit breaker 93 is shut off (step ST25).

As described above, in the fifth embodiment,
Of the current detectors 95, 98, and 103, the lower-side total current value is calculated by adding the current values detected by the lower-side current detectors 98 and 103. In a state where the current value detected by the upper current detector 95 matches, any one of the current values detected by the lower current detectors 98 and 103 exceeds the set current value. When this is detected, the lower circuit breaker in the overcurrent state is cut off, and the upper current detector 95 is turned off.
When the current value detected in step (1) exceeds the rated current value, the upper circuit breaker 93 is cut off, so that any one of the circuit breakers 93, 96, and 101 provided in each system is excessively large. When a large current flows, this is detected, and each of the circuit breakers 93, 96, 101 can be cut off in the order of the lower circuit breakers 96, 101 and the upper circuit breaker 93. Even if there is an individual difference between the overcurrent relays 99 and 104 and the current detectors 95, 98 and 103, the lower circuit breakers 96 and 101 can be turned off before the upper circuit breaker 93 can be turned off. Therefore, the coordination of the circuit breakers 93, 96, 101 can be enhanced.

Further, in the fifth embodiment, the overcurrent protection device 105 has the function of an overcurrent relay on the upper side, so that an overcurrent relay or the like is connected to the circuit breaker 93 on the upper side. The operation and the operation of setting the operating current value of the overcurrent relay can be omitted, and thereby the economy of the entire system can be improved.

As described above, in each embodiment, the sum of the lower-side current values obtained by the respective current detectors arranged on the lower side and the upper-side current value obtained by the current detectors arranged on the upper side are determined. Are compared to determine whether or not they match. However, even if they do not match, it is sufficient if they have a predetermined correspondence relationship.

[0071]

As described above, according to the present invention, in the overcurrent protection device according to the first aspect, even if there is an individual difference in each overcurrent relay, each current detector, and the like, any one of the respective systems can be used. When an overcurrent occurs, the lower circuit breaker can be shut off before the upper circuit breaker is shut off, thereby improving the coordination of the respective circuit breakers.

According to the overcurrent protection device of the second aspect, overcurrent protection of each system can be performed without using an overcurrent relay on the lower side, thereby reducing the system construction cost. When an overcurrent occurs in any of the systems, even if there is an individual difference between each overcurrent relay and each current detector, the lower circuit breaker is turned off before the upper circuit breaker is shut off. The circuit breaker can be cut off, thereby increasing the coordination of the respective circuit breakers.

According to the overcurrent protection device of the third aspect, overcurrent protection of each system can be performed without using any overcurrent relay, thereby making it possible to further reduce the system construction cost. When an overcurrent occurs in any of the systems, even if there are individual differences in each current detector, the lower circuit breaker can be shut off before the upper circuit breaker is shut off. Thereby, the coordination of each circuit breaker can be enhanced.

Further, according to the overcurrent protection device of the fourth aspect, overcurrent protection of each system can be performed without using an overcurrent relay on the upper side, thereby reducing the system construction cost. When an overcurrent occurs in any of the systems, even if there is an individual difference between each overcurrent relay and each current detector, the lower circuit breaker is turned off before the upper circuit breaker is broken. The circuit breaker can be shut off, thereby increasing the coordination of each circuit breaker.

In the power receiving equipment according to the fifth aspect, even if there is an individual difference between each overcurrent relay and each current detector, when an overcurrent occurs in any of the respective systems, the upper circuit breaker is activated. Before shutting down, the lower circuit breaker can be shut off, and even if the lower circuit breaker cannot be shut down by this, it can be shut down by the overcurrent relay, and thereby each circuit breaker can be shut down. Cooperation and security of the system can be compatible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a power receiving facility to which an overcurrent protection device according to the present invention is applied.

FIG. 2 is a flowchart showing an operation example of the power receiving facility shown in FIG.

FIG. 3 is a schematic configuration diagram showing a second embodiment of the power receiving equipment to which the overcurrent protection device according to the present invention is applied.

FIG. 4 is a flowchart showing an operation example of the power receiving facility shown in FIG.

FIG. 5 is a schematic configuration diagram showing an embodiment (third embodiment) of a power receiving facility according to the present invention.

6 is a flowchart showing an operation example of the power receiving facility shown in FIG.

FIG. 7 is a schematic configuration diagram showing a fourth embodiment of the power receiving equipment to which the overcurrent protection device according to the present invention is applied.

8 is a flowchart showing an operation example of the power receiving facility shown in FIG.

FIG. 9 is a schematic configuration diagram showing a fifth embodiment of the power receiving equipment to which the overcurrent protection device according to the present invention is applied.

10 is a flowchart showing an operation example of the power receiving facility shown in FIG.

FIG. 11 is a schematic configuration diagram illustrating an example of a conventionally known power receiving facility.

[Explanation of symbols]

1, 25, 45, 70, 90: Power receiving equipment 2, 26, 46, 71, 91: Power receiving end 4, 8, 13, 28, 32, 36, 48, 52, 57,
73, 76, 80, 93, 96, 101: Circuit breaker 6, 10, 15, 30, 34, 38, 50, 54, 5
9, 75, 78, 82, 95, 98, 103: current detectors 7, 11, 16, 31, 51, 55, 60, 99, 10
4: Overcurrent relays 17, 39, 61, 83, 105: Overcurrent protection device 18: Contact point 19: Operation circuit (upper-side cut-off condition determination unit) 20: Output circuit (interruption prohibition control unit) 40, 62: Operation circuit (Lower-side cut-off condition judging unit) 41, 63: Output circuit (cut-off control unit) 84, 106: Operation circuit (lower-side cut-off condition judging unit, upper-side cut-off condition judging unit) 85, 107: Output circuit (lower-side cut-off) Control unit, high-order cutoff control unit)

Claims (5)

[Claims] An overcurrent protection device in a power receiving facility that distributes received power to a plurality of systems and supplies the power to power devices provided in the respective systems, wherein each of the current detectors disposed on a lower side includes: An upper-side cut-off condition determining unit that compares the obtained sum of the lower-side current values with an upper-side current value obtained by a current detector arranged on the upper side and determines whether or not they have a predetermined correspondence relationship. And when the upper-side cut-off condition determining unit determines that the total of the lower-side current values and the upper-side current value have a predetermined correspondence relationship, prohibits the upper-side circuit breaker from being cut off. An overcurrent protection device comprising: a cutoff prohibition control unit; 2. An overcurrent protection device in a power receiving facility for distributing received power to a plurality of systems and supplying the power to power devices provided in the respective systems, comprising: In a state where the sum of the obtained lower-side current values and the upper-side current value obtained by the current detector arranged on the upper side have a predetermined correspondence relationship, one of the lower-side current values is set to the set current value. A lower-side cut-off condition determining unit for determining whether or not any of the lower-side current values exceeds the set current value. An overcurrent protection device comprising: a cutoff control unit that cuts off a lower circuit breaker that is: 3. An overcurrent protection device in a power receiving facility for distributing received power to a plurality of systems and supplying the power to power devices provided in the respective systems, wherein each of the current detectors disposed on a lower side includes: In a state where the sum of the obtained lower-side current values and the upper-side current value obtained by the current detector arranged on the upper side have a predetermined correspondence relationship, one of the lower-side current values is set to each lower-side current value. A lower cut-off condition determining unit for determining whether the current value exceeds a set current value; and the lower cut-off condition determining unit determines that any of the lower current values exceeds the lower set current value. When the overcurrent is detected, the lower-side cutoff controller that cuts off the lower-side circuit breaker that is overcurrent, and the upper-side current value obtained by the current detector located on the upper side exceeds the upper-side set current value. An upper-side cut-off condition determining unit for determining whether the When it is determined that the upper current value exceeds the upper set current value by the upper-side cutoff condition determining unit,
An overcurrent protection device, comprising: an upper-side cut-off control unit that shuts off an upper-side circuit breaker that is overcurrent. 4. An overcurrent protection device in a power receiving facility for distributing received power to a plurality of systems and supplying the power to power devices provided in each system, wherein each of the current detectors disposed on a lower side includes: In a state where the sum of the obtained lower-side current values and the upper-side current value obtained by the current detector arranged on the upper side have a predetermined correspondence relationship, one of the lower-side current values is set to each lower-side current value. A lower cut-off condition determining unit for determining whether the current value exceeds a set current value; and the lower cut-off condition determining unit determines that any of the lower current values exceeds the lower set current value. The lower-side cut-off control unit that shuts off the lower-side circuit breaker that is overcurrent, and the total of the lower-side current values obtained by the respective current detectors arranged on the lower side and the upper-side The upper current value obtained by the current detector In this state, an upper-side cut-off condition determining unit that determines whether the upper-side current value obtained by the current detector arranged on the upper side exceeds the upper-side set current value; When it is determined by the determination unit that the higher-side current value exceeds the higher-side set current value,
An overcurrent protection device, comprising: an upper-side cut-off control unit that shuts off an upper-side circuit breaker that is overcurrent. 5. The overcurrent protection device according to claim 2, wherein each lower side current value obtained by each lower side current detector exceeds a set current value for a predetermined time or more. And a plurality of overcurrent relays that, when it is determined that there is an overcurrent, cut off the lower-side circuit breaker that is overcurrent.