JPH0833183A - Digital protection controller - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to provide a digital protection controller having a starting device for improving reliability of an operation signal from a CPU to an output circuit without completely separating a hardware configuration. And A digital protection control device of the present invention reads a contact signal of the on / off state of a circuit breaker, determines a circuit breaker that has changed to a circuit break state, and outputs an operation signal to a main relay corresponding to the circuit breaker. A first judgment operation circuit that outputs a coded code indicating that this operation signal has been output, and an operation signal to the fail safe relay when the code received from this first judgment operation unit matches the specific code. The starting device includes a second determination calculation circuit for outputting and an output circuit for outputting a starting contact signal for performing stabilization control of the power system when the main relay and the fail-safe relay both operate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital protection control device for detecting an accident point in a power system and performing control for stabilization, and more particularly to a terminal device (starting device) thereof.

[0002]

2. Description of the Related Art FIG. 4 shows a system configuration example of a target power system. In FIG. 4, (a) shows a radial system and (b) shows a loop system. Electric station A, such as a power plant or substation,
Each of B and C has a power source 1 and a load 2, and each electric station is interconnected by a transmission line 3.

Further, as shown in FIG. 5, each electric station is equipped with breakers CB1 to CBn for various devices such as a generator 1, a load 2, a power transmission line 3, a transformer 4, a bus 5 and the like, which constitute the system of the electric station. Connected through. As a result, when a system accident, equipment failure occurs, or when inspecting equipment,
By cutting off the corresponding breaker, the corresponding section or device can be disconnected from the sound system.

Next, FIG. 6 shows the overall structure of the digital protection control device 6. Terminal devices (starting devices) 7A, 7B,
7C is provided in each electric station, detects the open / closed state of the circuit breaker, and transmits a start signal corresponding to the state change to the central processing unit 8. The central processing unit 8 is provided at an arbitrary place or at any electric place, and each terminal device 7A, 7B,
It receives the start signal from 7C and starts and executes the control calculation for system stabilization.

FIG. 7 is a block diagram of a start-up device 9 of a conventional digital protection control device, which is composed of a plurality of CPUs (judgment arithmetic circuits) that share processing.
The signals from the contacts 10 of the circuit breakers CB1 to CBn at each location of the electric station are input to the input circuit 11 and read by the CPU 1 (13) via the system bus 16 (a signal). CPU1
Detects the on / off of the circuit breaker from the information of these signals, determines the circuit breaker that has changed to the open (open) state, and outputs a corresponding operation signal to the output circuits 15A and 15B (c signal).

The output circuit 15A is a main relay (main detection relay) MXi (MXi is MX
1 to MXn), the output circuit 15B operates a fail-safe relay (accident detection relay) FDX, and outputs a corresponding start contact signal 18.

The reason why the two types of relays are operated in the output circuit is that the reliability is improved so that the start contact signal is not erroneously output due to one output circuit failure.

Note that the CPU 2 (14) is provided independently of the CPU 1 in order to share and execute the function processing such as automatic inspection, constant monitoring, display and settling of the starting device 9. Next, CPU
The process 1 will be described with reference to the logic diagram of FIG.

Circuit breakers CB1 to CBn at various points of the electric station
The signal from the contact 10 is input to the input circuit 11 and read by the CPU 1 (13) via the system bus 16 (a signal). In the CPU 1, the signals from the contact 10 are inverted by the NOT circuits 13A, 13B and 13C. That is, when CBi is turned on, the signal from the contact 10 becomes 1 and the output of the NOT circuit becomes 0. As a result, the main relay MXi and the fail-safe relay FDX of the output circuit of the next stage become inoperative, and the start contact signal is not output.

On the other hand, when CBi is off, the signal from the contact 10 becomes 0, and the NOT circuit outputs 1. As a result, the main relay MXi and the fail-safe relay FDX of the output circuit of the next stage are operated and the start contact signal is output.

[0011]

In the conventional starting device shown in FIGS. 7 and 8, the reliability is improved so that the starting contact signal is output by the AND condition of the two types of relays in the output circuit. . However, one CPU detects whether the circuit breaker is turned on or off, and two types of relays MXi are used.
And the start contact signal is output by operating the FDX. In other words, the relays MXi and FDX are CP
The operation signal from U1 is commonly used. In other words, since all processing is performed by one CPU, if an operation signal is erroneously output to the output circuit at the time of a runaway due to this CPU failure, the relays MXi and FDX may operate together and an erroneous start contact signal may be output. There is.

Further, although a measure for improving reliability by simply completely separating the hardware configuration and duplicating the device is conceivable, other problems such as enlargement of the device and expansion of installation space will occur.

The present invention has been made in order to solve the above-mentioned problems, and it is a CP without completely separating the hardware configuration.
It is an object of the present invention to provide a digital protection control device having a starting device for improving the reliability of the operation signal from U to the output circuit.

[0014]

The digital protection and control device of the present invention interconnects a plurality of electric stations, each of which is configured by connecting devices such as a generator, a transformer, and a transmission line through a breaker. The input circuit that inputs the contact signal that indicates the on / off state of the circuit breaker, and the contact signal is read from this input circuit to determine the circuit breaker that has changed to the off state. First, the operation signal is output to the main relay corresponding to the circuit breaker and the code indicating that the operation signal is output is output.
Both the main judgment circuit and the fail safe relay, and the second judgment calculation circuit that outputs the operation signal to the fail safe relay when the code from the first judgment calculation unit matches the predetermined code. It has a starting device provided with an output circuit that outputs a starting contact signal for performing stabilization control of the power system when operating.

Further, a current signal is inputted from an input circuit for inputting a contact signal indicating the on / off state of the breaker, and a current transformer for detecting a current flowing through the breaker provided corresponding to the transformer and the transmission line at the electric station. An analog circuit for inputting, a contact signal from the input circuit and a current signal from the analog circuit are read, and for a breaker capable of detecting a current signal, a breaker that has changed to a cut state using the contact signal and the current signal. For the circuit breaker that cannot detect the current signal, the circuit breaker that has changed to the cut state is judged using the contact signal, and the operation signal is output to the main relay corresponding to the circuit breaker. And a first judgment operation circuit for outputting a code indicating that the output is output, and a fail safe relay operated by receiving the code from the first judgment operation unit. And a starter having an output circuit for outputting a start contact signal for stabilizing the electric power system when the main relay and the fail-safe relay operate together. is there.

The first judgment operation circuit is established when the current signal is read from the analog circuit and operates when the current value is a predetermined value or more, and the breaker from the input circuit is turned on. A logical product circuit that produces an output when both the contact signal and the output signal from the current detection circuit are input and the output is inverted, and the operation signal is output to the main relay corresponding to the circuit breaker; 1 inverting circuit, a second inverting circuit for inverting a contact signal that is established when the breaker from the input circuit is turned on, and outputting an operation signal to the main relay corresponding to the breaker; And an encoder circuit that outputs a code to the second determination calculation circuit when at least one of the two inverting circuits outputs an operation signal.

The code output from the first judgment arithmetic circuit is passed to the second judgment arithmetic circuit as a specific code. Also, an operation signal is output from the first determination arithmetic circuit to the main relay via the first data bus, and an operation signal is output from the second determination arithmetic circuit to the fail-safe relay via the second data bus. It is a thing.

[0018]

[Function] When a certain circuit breaker (a plurality of circuit breakers are allowed) is switched from the on state to the off state due to a system accident or the like, the first judgment arithmetic circuit for reading the contact signal through the input circuit detects the circuit breaker changed to the off state. It detects and judges, and outputs an operation signal to the main relay corresponding to the circuit breaker. Alternatively, the first judgment arithmetic circuit that reads the contact signal through the input circuit and the current signal through the analog circuit detects and judges the breaker that has changed to the cut state, and outputs the operation signal to the main relay corresponding to the breaker. Output. At this time, the first determination calculation circuit outputs a code (a specific coded code) indicating that this operation signal has been output to the second determination calculation circuit.

The second judgment operation circuit detects and judges this code, and the data bus (second
The operation signal is output via the data bus). Then, when both the main relay and the fail-safe relay operate, a start contact signal for stabilizing the power system is output from the output circuit.

In other words, the first judgment operation circuit carries out the operation processing (judgment / output) of the main relay, and the second judgment operation circuit carries out the operation processing of the fail-safe relay.
Further, a data bus for passing a specific code from the first determination arithmetic circuit to the second determination arithmetic circuit and transmitting an operation signal from the first determination arithmetic circuit to the main relay, and a fail safe relay from the second determination arithmetic circuit. Separated from the data bus that passes the operation signal to. As a result, it is possible to obtain a highly reliable start-up device and even a highly reliable digital protection control device without duplicating the hardware configuration.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the same parts as those in FIG. 7 are designated by the same reference numerals, and in FIG. 2, the same parts as those in FIG. 8 are designated by the same reference numerals.
The starting device (terminal device) 19 of the digital protection control device of the present invention includes an input circuit 11, an analog circuit 12, a first judgment calculation circuit (hereinafter, referred to as CPU 1) 20, and a second judgment calculation circuit (hereinafter, referred to as CPU 1). , CPU2) 21, output circuits 15A, 15
B, a system bus (first data bus) 16 and a direct bus (second data bus) 17. Although the analog circuit 12 will be described in another embodiment, it is described in this drawing because the drawing is commonly used.

The input circuit 11 inputs signals (contact signals) from the contacts 10 of the circuit breakers CB1 to CBn of equipment such as lines at electric stations, generators, transformers, etc., and outputs CP via the system bus 16.
Output to U1 (a signal). The CPU 1 detects the on / off state of the circuit breaker from the information of these contact signals, determines the circuit breaker that has changed to the cut (open) state, and outputs a corresponding operation signal to the output circuit (main relays MX1 to MXn) 15A. (D signal). When the CP1 outputs at least one operation signal, the CP1 outputs a code indicating the output to the CPU2 (e signal). The CPU 2 receives the code from the CPU 1 and outputs an operation signal to the output circuit (fail safe relay FDX) 15B via the direct bus 17 (f signal). And the output circuit (main relays MX1 to M
Xn) 15A and output circuit (fail safe relay FD
X) 15B outputs a start contact signal 18 to a central processing unit that controls the stabilization of the power system when both of them operate.

FIG. 2 is a detailed logic diagram of the CPU 1.
The contact signal from each breaker is NOT circuit (inversion circuit) 13
Input to A, 13B and 13C and inverted. In other words, when the circuit breaker is in the ON state, contact signal = 1, NOT circuit output = 0
Therefore, when the circuit breaker is in the off state, the contact signal = 0
Then, the cut-off of the circuit breaker is detected and judged by the NOT circuit output = 1. Then, the output of the NOT circuit becomes an operation signal and is output to the main relay MXi of the output circuit 15A corresponding to the breaker in the cut state. Of course, when there are a plurality of circuit breakers in the cut state, the operation signal is output to the corresponding main relay.

The OR circuit (logical sum circuit) 13D is N
The outputs of the OT circuits 13A, 13B, and 13C are input, and an output is generated when the output of at least one NOT circuit is established, and the encoder 13F receives the output of the OR circuit 13D and outputs a code. Here, this code is, for example, a plurality of bits (e
x. 16 bits, 32 bits) is used as a specific code (ex. Hexadecimal number 5555, AAAA).

The decoder 21A of the CPU 2 inputs a code from the encoder 13F of the CPU 1 via the system bus and decodes it. If the input code is a predetermined specific code, the operation signal is directly directed to the fail safe relay FDX of the output circuit 15B. Output via bus 17.

Next, the operation of the digital protection control apparatus of the above embodiment will be described. The digital protection control device always (periodically) captures circuit breaker information to detect and determine the presence or absence of a circuit breaker that has changed to a cut state. Now, if an accident occurs in the system, a protective relay device (not shown) operates and the corresponding breaker (eg CB1, CBi) is turned off so as to separate the accident section from the system. CPU
1 detects the contact signal of this circuit breaker via the input circuit 11 and judges the circuit breakers CB1 and CBi which are in the cut state due to the outputs of the NOT circuits 13A and 13B being established, and the correspondence of the output circuit 15A An operation signal is output to the main relays MX1 and MXi via the system bus 16. Further, the OR circuit 13D is established by the operation signal, and the encoder 13F outputs a specific code to the CPU 2 via the system bus 16.

Then, the CPU 2 inputs this code, and when it confirms that the code matches the predetermined code, the output circuit 15B
The operation signal is output to the fail safe relay FDX of through the direct bus 17. As a result, the main relays MX1 and MXi of the output circuit 15A and the fail-safe relay FDX of the output circuit 15B both operate, and a start contact signal is output to the central processing unit. The central processing unit inputs the start contact signal from the starter of the electric station, judges the system configuration of the power system after the accident from the information of the circuit breaker that has been turned off, and performs the necessary stabilization control according to the system configuration. carry out.

As described above, in the start-up device, the main relay of the output circuit 15A and the fail-safe relay of the output circuit 15B are operated by the operation signals determined by the different CPUs, so that the failure of one CPU (runaway etc.) It is possible to prevent the output of the false start contact signal due to the error, and to obtain high reliability.

Further, by encoding the signal from the CPU1 to the CPU2, the possibility of accidentally obtaining the same code is extremely small, so that the failure ripple from the CPU1 to the CPU2 can be surely suppressed and the reliability is further improved. It leads to improvement of sex.

Further, by separating the system bus 16 from the CPU 1 to the output circuit 15A and the direct bus 17 from the CPU 2 to the output circuit 15B, the reliability is further improved.

Next, another embodiment will be described with reference to FIG. 3, the same parts as those in FIG. 2 are designated by the same reference numerals. In this embodiment, the change of the breaker in the CPU 1 to the cut state is detected and determined from the contact signal of the breaker and the current signal of the breaker. That is, the analog circuit 12 inputs the current signal from the current transformer CT (see FIG. 5) installed in the power transmission line and the transformer, digitally converts it, and passes it to the CPU 1 (b signal). The current detection circuit (51P) 13E of the CPU 1 detects this current signal and sets the output to 1 when the current value is equal to or higher than the predetermined value. And the AND circuit (logical product circuit) 13G,
13H inputs the contact signal of the circuit breaker from the input circuit 11 and the output signal from the corresponding current detection circuit 13E, and when both are established, produces an output and passes it to the NOT circuit in the subsequent stage.

Depending on the location of the circuit breaker, such as a line or a transformer, depending on the system configuration of the electric station, a load current may flow when the circuit breaker is on (connected). Then, this current is detected, and the condition that the circuit breaker is turned on when the current value is a predetermined value or more, and the circuit breaker is turned off when the current value is a predetermined value or less is used. The present invention can also be applied to those having a circuit for detecting and determining the cut state of the circuit breaker as described above.

[0033]

As described above, according to the present invention, the operation signal to the relay is shared by a plurality of judgment calculation circuits (CPU) and judged without duplicating the hardware structure, so that the start-up is highly reliable. A digital protection controller with the device can be obtained.

In addition, the signal from the first judgment arithmetic circuit to the second judgment arithmetic circuit is encoded, or the bus from the first judgment arithmetic circuit to the output circuit and the output circuit from the second judgment arithmetic circuit to the output circuit. Further reliability can be obtained by separating the bus to and from the bus.

[Brief description of drawings]

FIG. 1 is a block diagram of an activation device of a digital protection control device according to the present invention.

FIG. 2 is a block diagram of an activation device of the digital protection control device of the present invention.

FIG. 3 is a block diagram of an activation device of a digital protection control device according to another embodiment.

FIG. 4 is a diagram showing a system configuration example of a power system applied to a digital protection control device.

FIG. 5 is a diagram showing an example of a system configuration of an electric station.

FIG. 6 is a block diagram of a digital protection control device.

FIG. 7 is a block diagram of a conventional activation device for a digital protection control device.

FIG. 8 is a block diagram of a conventional activation device for a digital protection control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power supply, 2 ... Load, 3 ... Transmission line, 4 ... Transformer, 5 ... Bus line, 6 ... Digital protection control device, 7A, 7B, 7
C, 9, 19 ... Terminal device (starting device), 8 ... Central processing unit, 10 ... Breaker contact point, 11 ... Input circuit, 12 ... Analog circuit, 13, 14, 20, 21 ... Judgment calculation circuit (CPU), 15A,
15B ... Output circuit, 16, 17 ... Bus, 18 ... Start contact output, 13
A, 13B, 13C ... NOT circuit, 13D ... OR circuit, 13F ...
Encoder, 13E ... Current detection circuit (51P), 13G, 13H
... AND circuit, 21A ... Decoder, CBi ... Breaker, C
T ... transformer.

Claims (5)

[Claims] 1. A digital type for stabilizing control of an electric power system in which a plurality of electric stations configured by connecting devices such as a generator, a transformer, a transmission line, etc., respectively, through a circuit breaker are interconnected. In the protection control device, an input circuit that inputs a contact signal indicating the on / off state of the circuit breaker, and a contact signal is read from this input circuit, the circuit breaker that has changed to the cut state is determined, and the main relay corresponding to the circuit breaker is determined. A first judgment operation circuit that outputs an operation signal and a code indicating that the operation signal is output, and a fail safe when the code from the first judgment operation unit is received and the predetermined code matches. A second judgment arithmetic circuit that outputs an operation signal to the relay, and a start contact signal that performs stabilization control of the power system when both the main relay and the fail-safe relay operate. A digital protection control device having a starting device provided with an output circuit for outputting. 2. A digital type for stabilizing control of a power system formed by connecting a plurality of electric stations configured by connecting devices such as a generator, a transformer, and a transmission line via breakers. In the protection control device, an input circuit for inputting a contact signal indicating the on / off state of the breaker, a transformer at an electric station, and a current transformer for detecting a current flowing through the breaker provided corresponding to the transmission line. An analog circuit for inputting a signal, a contact signal from the input circuit and a current signal from the analog circuit are read, and a breaker capable of detecting a current signal is changed to a cut state by using the contact signal and the current signal. For the circuit breaker that cannot detect the current signal, use the contact signal to determine the circuit breaker that has changed to the cut state, and then determine the main circuit corresponding to the circuit breaker. To the fail-safe relay by receiving the code from the first determination calculation circuit that outputs the operation signal to the relay and the code indicating that this operation signal has been output. And a starter having an output circuit for outputting a start contact signal for stabilizing the power system when the main relay and the fail-safe relay operate together. Digital protection control device. 3. The current detection circuit according to claim 2, wherein the first judgment arithmetic circuit reads a current signal from the analog circuit and operates when a current value is a predetermined value or more, and a breaker from the input circuit. When the contact signal that is satisfied when the switch is turned on and the output signal from the current detection circuit are input, an AND circuit that produces an output when both are input, and the output of this AND circuit is inverted to operate the main relay corresponding to the circuit breaker. A first inverting circuit that outputs a signal and a second inverting circuit that inverts a contact signal that is established when the breaker from the input circuit is turned on and outputs an operation signal to a main relay corresponding to the breaker.
And an encoder circuit that outputs a code to the second determination calculation circuit when at least one of the first and second inversion circuits outputs an operation signal. Protection control device. 4. The digital protection control apparatus according to claim 1, wherein the code output from the first determination calculation circuit is passed to the second determination calculation circuit as a specific code. 5. An operation signal is output from the first determination calculation circuit to a main relay via a first data bus, and the second relay outputs the operation signal.
3. The digital protection control apparatus according to claim 1 or 2, wherein an operation signal is output from the judgment calculation circuit of claim 1 to the fail-safe relay via the second data bus.