JPS6026499A - Air breaker for protecting generator - Google Patents

Abstract

PURPOSE:To suppress the transient rush current caused by a voltage generated at a load by adding a checking function of the phase state of other power source in an electric closing unit of an air breaker. CONSTITUTION:The frequencies of a generator (A) to be connected to a switchboard bus and a generator (B) already connected to a load are inputted to a speed discriminator 9 and a phase detector 5. The discriminator 9 outputs a rotation up or down signal to the governor of the generator A to bring the frequency of the generator A into coincidence to that of the generator B. On the other hand, a phase detector 5 detects the voltage phases of the generators A, B, and outputs its output to a possible connection frequency detector 6 and a connecting time detector 7. A connection detector 8 collects the timing that the outputs from the detectors 6, 7 become simultaneous, excites a relay RyX to close a contactor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air circuit breaker for protecting a generator, and in particular to an air circuit breaker for protecting a generator, which is applicable to protecting generators such as marine generators and generators for private power generators. Concerning vessels.

In an air circuit breaker (80B) generally used for generator protection, the distribution amount H07 is one, as shown in Figure 1 (A) and (B), respectively. In a system in which one or more generators 02 are connected to the AC803, the operation of the power supply device using the AC803 does not pose a particular problem, but in a ship's power supply system as shown in Figure 2, The disadvantage is that the contact closes immediately upon operation of the ACB operation switch, regardless of the phase state of the power supply.

In addition, ships are equipped with multiple generators as shown in Figure 2, and are equipped with automatic power switching for important loads, taking into account damage or generator failure that is different from general merchant ships due to their characteristics. It is common to use ABT to provide multiple power distribution.

Below, using FIG. 2, the reason why the operation of the conventional ACB power-on device is defective and its contents will be described.

■ When the No. 1 and No. 2 generators 05 and 06 connected to the No. 1 and No. 2 switchboards 011 and 012, respectively, are healthy and in operation, the loads 1 and 3 are supplied from the No. 1 generator 05, which is the regular power supply, to the loads 2 and 2. 4 are respectively supplied with power from the No. 2 generator 06, which is also a regular power supply.

If the voltage of No. 1 bus 07 drops below the rated voltage of 40 to 65 inches due to failure of No. 1 generator 05 in the state of ■ ■, ABT 09 used for loads 1 and 3 will automatically adjust the voltage. Switched to the healthy No. 2 bus 08 side and continued 2
Receives power supply from issuer % machine 06.

■ The failure of No. 1 generator 05 has recovered from the state of ■, and the ACB for No. 1 generator O,? When (7G-ACB) is turned on, the voltage of No. 1 bus 07 returns to the rated state, so ABT 09 used for loads 1 and 3 is automatically changed to instantaneous (20-520-5O) again. It switches to the No. 1 bus 07 side and receives power again from the No. 1 generator 05.

Here, if the loads J and 3 are disconnected from the power source during operation (energized), such as induction motors, and if they have a power generation effect even for a short time, the state of
At the moment when the C-ACB is turned on, two different power sources form one closed circuit.Depending on the phases of the voltages generated by loads 1 and 3 and the No. 1 generator In this case, the phases of the voltages generated by the No. 1 generator 0-5 and the induction motor may be in opposite phases.) Therefore, an excessive transient inrush current will flow.

It is generally well known that the voltage generated by an induction motor can be approximately expressed by the following equation.

■;-〆”mLmI2oε-h (Q)m+φ0) where ω.-Rotor angular velocity Lm=excitation inductance I
2G"" Effective value of secondary current immediately after opening 'l'o = Opening time constant Also, the phase of the generated voltage is the same as that immediately before opening because the switching time of ABT 09 is very short (20 msec to 50 m 5ec). It can be considered that the power supply phase continues.

Next, we will discuss specific problems caused by the aforementioned transient inrush current.

(7) The instantaneous tripping mechanism of the embedded circuit breaker (AQB) 070 used to protect the power supply line to each load operates and the power supply is stopped.

(a) In the worst case, an induction motor is directly started at about twice the rated voltage, so about four times the starting torque when energized is generated, and there is no adverse effect on the shaft or driven machine side.

(Run) The constant pressure in the power supply system fluctuates instantaneously, leading to malfunctions of various electrical devices.

2) The contacts of the electromagnetic contactor installed in the ABT 09 and auxiliary equipment starter become rough.

As described above, (in the conventional example, since most of the power consuming devices onboard the ship are induction motors), the problems described in (7) to (above) occur.

In particular, regarding (7), in order to prevent the instantaneous tripping mechanism from operating, the rated current of the AQB is selected to be larger than that of the induction motor.

In addition, due to the rated current of the AQB, it often happens that the rated current of the induction motor makes it impossible to secure the overcurrent of the electric wire, and it becomes necessary to increase the size of the wire to the size of a stain. There is.

Therefore, it has been desired to optimize these.

The present invention was proposed in view of the above circumstances, and its purpose is to add a function to check the phase status of other power sources to the conventional ACH power-on device.
It is an object of the present invention to provide an air circuit breaker for generator protection which can suppress excessive inrush current caused by the voltage generated by a load and eliminate the various drawbacks of the conventional devices.

The air circuit breaker for generator protection according to the present invention includes a speed determination section that detects the alternating current voltage of two alternating current generators and controls the speed governor according to the difference in frequency, and a speed determination section that performs control by this speed determination section. and a drive time and rest time adjustment section that sets the drive time and rest time of the speed governor, respectively, and a logical product of the respective outputs from the speed determination section and the drive time and rest time adjustment section to operate the relays, respectively. a speed increase/decrease command unit, a phase detection unit that detects the phase difference between the two alternating current voltages, and a phase detection unit that detects the cycle of the stain pressure output from this phase detection unit to determine that a specified time has elapsed. a closing frequency detection unit that determines whether the output value output from the phase detection unit is a specified value, a closing timing detection unit that determines whether the output value output from the phase detection unit is a specified value, and each of the closing timing detection unit and the closing oJ function frequency detection unit. A closing detection section operates a relay and closes an air circuit breaker based on the logical product of the outputs, and a closing detection section that compares the output from one AC voltage frequency counter with a reference value and outputs that output to the drive time and rest time adjustment section mentioned above. a constant frequency control section that controls the frequency of the speed governor by inputting it to the speed increase/decrease command section;
an alarm generation section that compares the output from the constant frequency control section with an alarm setting value and outputs an alarm and a cutoff signal for the air circuit breaker; and an alarm generation section that is connected to one of the AC voltage sources to control each of the above sections. It is characterized by comprising a control power supply section,
The CH is provided with a synchronization function so that the ACH contactor closes when the phase of the generator voltage to be restarted matches the phase of the voltage generated by the load (induction motor, etc.).
By providing the control function of the prime mover governor to the CH, constant frequency control is possible, and in addition, the frequency abnormality (lowering or excessive rise) to the ACH can be detected.
It is equipped with an alarm and an automatic ACH line removal function.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is an electric circuit diagram showing the configuration of an embodiment of the present invention, FIG. 4 is a block diagram showing the detailed configuration of the phase detection section in FIG. 3, and FIG. 5 is the phase detection section shown in FIG. 4. FIG.

In Fig. 3, 1 is a contact, 2 is a voltage train disconnection device, 3 is an electric energizing device, 4 is an overcurrent exception device, 5 is a phase detection section, 6 is a closing frequency detection section, and 7 is a closing timing detection section. , 8
9 is a supply detection section, 9 is a speed determination section, 0 is a drive time setting section, 1 is a rest time setting section, 12 is a speed increase command section, 13
Reference numeral 4 indicates a speed reduction command section, numeral 4 indicates a constant frequency control section, numeral 15 indicates an alarm generation section, and numeral 16 indicates a control power supply section.

In FIG. 3, the frequencies of the generator that is about to be input to the switchboard bus (hereinafter referred to as machine A) and the generator that is already supplying power to the load (hereinafter referred to as machine B) are determined by the speed determination unit 9.
and is input to the phase detection section 5.

The speed determination unit 9 compares the frequencies of aircraft A and B, and
Match the frequency of 'AI!
and Ryl.

Note that the operating time and rest time of the speed governor are automatically adjusted by the drive time setting section 10 and the rest time setting section 1) depending on the magnitude of the frequency difference, and the phase can be detected and the output can be applied to the frequency detection section. , 6 and the input timing detection section 7.

The possible input frequency detection section 6 and the input timing detection section 7 independently output to the input detection section 8 at timings that optimize the frequency difference and the input timing.

Closing detecting section 8 captures the timing when the outputs from closing frequency detecting section 6 and closing timing detecting section 7 are simultaneous, and excites relay Ryx to operate electrical closing device 3 and close contactor 1 of ACH.

The constant frequency control section 14 detects that the contactor 1 of the ACB is closed and operates in place of the speed determination section 9. The constant frequency control section 14 detects that the ACB contact 1 is closed and operates in place of the speed determination section 9. In this case, a speed governor raising or lowering command is output to control the generator frequency to be constant.

Still, the alarm generator 15 outputs a jurisdiction or ACB cutoff signal when the frequency significantly decreases or increases relative to the set value.

In addition, in the case of a cut-off signal, the voltage tripping device 2 is operated and the AC
Shut off the H contact.

The operation of the above embodiment of the present invention will be explained.

For convenience of explanation, each part shown in FIG. 3 will be explained.

In Fig. 3, the configuration and operation of the contactor 1, voltage tripping device 2, electricity closing device 3, and overcurrent line disconnecting device 4 are the same as those of the conventional ones, so their explanation will be omitted, and each part other than these will be described below. Explain.

(7) Speed judgment unit 9゜When two AC voltages are detected by a transformer and combined on the secondary side of the transformer, if there is a difference in frequency, the difference becomes a stain pressure, and the difference between the two frequencies is High.

By using the principle that the phase rotation direction of low and high stain pressure and the frequency of low and high stain pressure are determined, relays RyR and Ry are used, respectively.
L is excited and the speed governor is driven and controlled by the contact output.

(a) A driving time and resting time adjusting section including the driving time setting section 10 and the resting time setting section 11.

In order to set the driving time of the speed governor according to the characteristics of the prime mover and speed governor, the driving time and rest time can be determined by detecting the cycle of the stain pressure mentioned above, that is, the frequency difference, and using, for example, a CR circuit or a logic circuit. Set each.

(1) Speed increase command section 12 and speed decrease command section
3.

Relay RyR or RyL is operated by the logical product of the outputs from speed determination section 9 and drive time setting section 10, respectively.

B) Phase detection unit 5゜As shown in Fig. 4, it includes a circuit for generating stain pressure as described in (7) above, waveform shaping circuits 2 and 22, logic circuits 23 and 24, and a pulse counter 25 and D. /A converter 26 and pulse oscillator 27, and the phase difference is the fifth
Detection is performed in the following manner as shown in the figure. Waveform shaping circuit 21.
22 has two circuits, one for the generator that is about to be turned on and the other for the generator that is already being supplied with power, and shapes the AC waveforms of each into /4' pulses. The pulse waveform is output to the logic circuit 23, and the logic circuit 23 outputs it to the next logic circuit 24 only during the period when both outputs overlap. The logic circuit 24 transmits the pulse from the pulse oscillator 27 to the pulse counter 25 at the next stage only during a period when the logic circuit 23 has an output. Thereafter, the converter 26 converts it into an analog quantity and outputs it to the input timing detection section 7.

(6) Closing possible frequency detection unit 6゜The cycle of the glue stain pressure from the phase detection unit 5 of the above) is detected by, for example, a logic circuit or a CR circuit, and it is determined that it is a specified time and output to the closing detection unit 8. do.

(2) Closing timing detection unit 7゜For example, it is composed of a comparison circuit and a logic circuit, and is a D/A of the above-mentioned)
It is determined that the output from the converter 26 is a specified value and output to the input detection section 8.

←) Closing detection unit 8゜For example, it is composed of a logic circuit, and excites the relay RyX by the logical product of 0) and (a) above, and further activates the ACB electricity closing device 3.
Operate and insert JCB.

) Constant frequency control unit 14゜For example, a waveform shaping circuit, a frequency counter, a D/A converter,
It consists of a comparison circuit, which converts the output from the frequency counter and then compares it with a reference value. This output is the drive time setting section 1
0. The signal is sent to speed increase/decrease command units 12 and 1.9, and frequency control is performed by exciting the relay RyR or RyL and driving the speed governor.

(2) Alarm generation unit 15°, which is composed of, for example, a comparison circuit, compares the output from the above-mentioned (a) with an alarm set value, and outputs a contact signal to the outside.

(j) Control power supply section 16°A The control power supply section is connected to the alternating current Irt and voltage source of the machine, and its output side is connected to the above-mentioned sections 5 to 5, and controls each section 5 to J5.

As described above, according to the present invention, since the ACB can be turned on almost in synchronization with the voltage generated by the load (induction motor, etc.), the transient inrush current that occurs when switching the ABT can be suppressed, and the ACB can be turned on. After that, excellent effects such as constant frequency control of the generator are made possible.

[Brief explanation of the drawing]

1(A), 2(B) and 2 are schematic wiring diagrams showing the configuration of a conventional example, FIG. 3 is an electric circuit diagram showing the configuration of an embodiment of the present invention, and FIG. 4 is a schematic wiring diagram showing the configuration of an embodiment of the present invention. A block diagram showing the detailed configuration of the phase detection section in FIG. 5 is an operation waveform diagram of the phase detection section shown in FIG. 4. J...Contactor, 2...Voltage string disconnection device, 3...Electricity closing device, 4...Overcurrent string disconnection device, 5...Phase detection section, 6...Turning possible frequency detection Department? ... Closing time detection unit, 8... Closing detection unit, 9... Speed determination unit, 10... Driving time setting unit, 1 No... Pause time setting unit, 12... Speed increase command unit , 13... Speed reduction command section, 14... Constant frequency control section, 15... Alarm generating section, 16... Control power supply section. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] A speed determination section detects the alternating current voltages of the two alternating current generators and controls the speed governor according to the difference in frequency, and the drive time and rest time of the speed governor are controlled by this speed determination section. a drive time and rest time adjustment section that respectively sets the speed determination section and the drive time and rest time adjustment section; a speed increase and decrease command section that operates the relays by the AND of each output from the speed determination section and the drive time and rest time adjustment section; a phase detection section that detects a phase difference of alternating current voltage; a turn-on frequency detection section that detects the period of the stain pressure outputted from the phase detection section and determines whether it is a specified time; and the phase detection section. A closing timing detection section that determines whether the output value outputted from the closing timing detection section is a specified value, and a logical product of each output from this closing timing detection section and the closing possible frequency detection section to operate a relay and create an air circuit breaker. Compares the output from the frequency counter of one AC voltage with the reference value, and inputs the output to the drive time and rest time adjustment section to increase the speed mentioned above, and inputs it to the command section to adjust the above. a constant frequency control section that controls the frequency of the speed machine; an alarm generation section that compares the output from the constant frequency control section with an alarm setting value and outputs an alarm and a cutoff signal for the air circuit breaker; 1. An air circuit breaker for protecting a generator, comprising: a control power supply section connected to an AC voltage source to control each of the above sections.