JPS61170298A - Power generation controller - Google Patents

Abstract

PURPOSE:To switch from a phase modifying operation to a generating operation without fluctuation to a system by providing a keep relay which becomes a reset state by the operation of a system frequency decrease detecting relay and a load change rate converter for converting a load change rate to zero in conjunction with the keep relay. CONSTITUTION:When a system frequency decrease detecting relay 9 operates during a phase modifying operation, an auxiliary relay 11 is excited, its contact 11a2 is closed, a U.F. bias signal 12S is input to a governor unit 2, and a keep relay 12 is set. An inner relay S8 of the unit 2 is excited in cooperation with the relay 12, and a normal-open contact S8a is closed. The output of a load change rate converter 6 becomes zero by this shortcircuit, and a governor unit auxiliary relay 8 is nonexcited. Thus, an input to an integrator 7 is switched from the set value of a setter 4 to a generator output 1, and the output of the integrator 7 is followed to the output 1.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is directed to a water turbine generator (hereinafter referred to as a generator) that is installed in a small-scale system and is operated in a phase-adjusted manner. The present invention relates to a power generation control device that switches to power generation operation at certain times and stably switches to operation using a load setting device when the system frequency is restored.

[Technical background of the invention and its problems]

In the operation of a plurality of generators connected in parallel in a small-scale system, the opening and closing of guide vanes is generally controlled by an output signal from a governor unit 2 which feeds back the generator output 1.

This output is inputted to the governor unit 2 as a set value by the load setting device 3.

In this way, before the generator is connected to the grid, the load is set using the load setting device, and after the generator is connected, the load is automatically taken up to the set value at a predetermined rate. There is an operation (hereinafter referred to as "knee/action operation") in which a generator in phase operation is switched to power generation operation in a short time to restore the grid frequency.

Regarding the above-mentioned operation, a conventional power generation control device will be explained with reference to Fig. 2.The load setting device 3 operated by the electric motor 4 and the setting value of this load setting device 3 are input, and the generator is in generating operation before entering the grid. After inputting zero, the input switching circuit 5 outputs the set value, the load change rate switching circuit 6 inputs this output via an arithmetic unit and a limiter circuit, and the selected rate of change and the governor unit auxiliary relay 8. An integrator 7 connected by a contact, a device that takes the deviation between the output of this integrator 7 and the generator output 1, and outputs a ΔP signal IS, and the output of this integrator 7 is fed back to the output of the load setting device 3. A set of the keep relay 12, which is composed of a governor unit 2 consisting of a line to set the system frequency, an auxiliary relay 11 that is energized by the operation of the normally open contact of the system frequency drop detection relay 9, and a keep relay 12 that is set to the set state by the operation of this auxiliary relay. state, the circuit is closed and the N.F. bias signal 128 is sent to the governor unit.
A line that connects the line, a line that closes when the keep relay 12 is in the reset state and excites the governor unit auxiliary relay 8 in the governor unit, and a line that closes the keep relay 12 to excite the governor unit auxiliary relay 8 in the governor unit, and the keep relay 12 to switch from the NFC action operation to the operation using the setting device. It is composed of a return switch 13 that brings the device into a reset state.

When the generator is in phase adjustment operation, the set value of the load setting device is set to the system frequency with zero being output by the input switching circuit 5 and the guide vanes of the water turbine being fully closed by the output signal of the governor unit. When the system frequency decreases, the system frequency drop detection relay 9 operates, and the auxiliary relay 11 is energized under the condition that the parallel circuit breaker 10 is closed, and the normally open contact 11a1 of this auxiliary relay 11 is closed, and the keep relay 12 is in the set state. The contact 12a linked to this keep relay 12
The N.F. bias signal 12S that maximizes the output is input to the governor unit 2, and the guide vane of the water turbine opens due to the output signal of the governor unit 2, increasing the output 1 of the generator, which increases the power to the grid. It will be in power generation operation to supply electricity. Note that the keep relay 12 is in a reset state from the auxiliary contact 10b of the parallel circuit breaker before the generator is connected in parallel. When the above-mentioned keep relay 12 is set, the N.F. bias signal is input to the governor unit, and at the same time, the contact 12b is opened and the governor unit auxiliary relay is de-energized, so the contact 8a is opened and the contact 8b is closed. The input of the integrator is switched from zero to a feedback amount of the generator output, and the output of this integrator follows the output of the generator.

When the system frequency returns to normal after the power generation operation described above, the system frequency drop detection relay returns to normal, the contact 9 opens and the auxiliary relay 11 becomes de-energized, but the keep relay 12
remains set, the N.F. bias signal 128 continues to be input, and the output of the governor unit 2 is at its maximum level, so the generator output 1 is operated to the rated output regardless of the system frequency recovery. become. In order to switch from this knee-f action operation to operation using the load setting device, it is necessary to close the contact 13a of the knee-f action operation return switch and return the keep relay 12 to the reset state. Due to the reset state of this keep relay 12, the N.F. bias signal 12
The contact of the line 8 is opened and the contact 12b is closed, energizing the governor unit auxiliary relay 8, and the contact 8a is closed.
and 8b, the input to the integrator is switched from the output 1 of the generator to the output from the load setting device 3, and power generation operation is performed.

In the above-mentioned conventional technology, since the phase control operation is switched to the power generating operation and the generator is operated at the rated output regardless of the return of the grid frequency, the grid frequency may rise above the reference frequency. There was a risk that generator output 1 would overshoot and cause disturbance to the grid. If the set value of the load setting device 3 is smaller than the output of the integrator that was following the output 1 of the generator when the N.F. action return switch 12 is operated, the output 1 of the generator will be set to this set value. The problem is that the system frequency drops to There was a problem in that it was a heavy burden to carry out and could lead to operational malfunctions.

[Purpose of the invention]

In the present invention, when a plurality of generators connected to a small-scale grid are in NEF action operation, the setting value of the load setting device 3 is made to follow the output 1 of the generator, and the grid frequency To provide an activation control device for the purpose of automatically switching to operation using the load setting device 3 without causing disturbance to the system at the time of recovery.

[Summary of the Invention] According to the present invention, a keep relay that is set to a set state by the operation of a grid frequency drop detection relay, a load change rate switching circuit that switches the load change rate to zero in conjunction with this keep relay, and an integrator. It is equipped with a comparator that detects the deviation between the output and the set value of the load setting device, and a device that drives the load setting device to eliminate this deviation, and is equipped with a device that drives the load setting device to eliminate this deviation. Since the output of the generator is input to the integrator, the output of the integrator follows the output of the generator.

At this time, the comparator detects the deviation between the output of the integrator and the load set value, and the device for driving the load setter is used to make the set value follow the output of the integrator, that is, the output of the generator. To provide a power generation control device characterized in that stable switching is performed using a load setting device without causing disturbance to a power system.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG. 1. The feature of the present invention is that the normally open contact 1 of the auxiliary relay 11 is energized by the operation of the grid frequency drop detection relay in the conventional power generation control device.
1a2 in the line of the N.F. bias signal that enters the governor unit, and the normally closed contact 11 of the auxiliary relay.
b1 is provided in the line that excites the governor unit auxiliary relay 8, which has a contact that switches the input to the integrator, and a contact 12a1 is provided that closes when the keep relay 12 is set and energizes the internal relay S8 of the governor unit. In addition, a short circuit is provided in the load change rate switching circuit 5 with the normally open contact S6a of the internal relay S8, and a comparator is provided to detect the deviation between the output of the integrator 7 and the load setting value. 13 and a raising auxiliary relay 1 that is energized by the output of this comparator when the set value is smaller than the integrator output.
The lowering auxiliary relay 15 is energized when it is greater than 4, and the return auxiliary relay 16 for the keep relay 12 is energized when it is equal to 4. In addition, the control circuit for driving the load setting device 4 is operated by closing the contacts of the raising auxiliary relay 14, and the control circuit for driving the load setting device 4 by closing the contacts of the raising command auxiliary relay 17 and the lowering auxiliary relay 15. The normally open contacts 16a of the lowering command auxiliary relay 18 for operating the circuit and the auxiliary relay 16 for returning the keep relay are provided in the circuit for setting the keep relay to the reset state.

When a generator with the above configuration is connected to the grid and the grid frequency drop detection relay 9 operates during phase adjustment operation, the normally open contact 9 is closed, the auxiliary relay 11 is energized, and the normally open contact 11a2 is activated. is closed, and the NFC bias signal 128 that maximizes the output is input to the cover unit 2.

Further, the normally open contact 11a1 of the auxiliary relay 11 is closed to set the keep relay 12. In conjunction with this keep relay 12, contact 12a1 closes, energizing internal relay S8 of governor unit 2, and normally open contact S8a closes.

This short circuit causes the output of the load change rate switching circuit 6 to become zero. At the same time, the normally closed contact 11b1 is opened by the energization of the auxiliary relay 11, the governor unit auxiliary relay 8 is de-energized, the contact 8a in the governor unit 2 is opened, the contact 8b is closed, and the input to the integrator 7 is The setting value of the setting device 4 is switched to the generator output 1 fed back from the generator, and the output of the integrator 7 follows the generator output 1.

As mentioned above, by the N.F. bias signal 12S,
The generator switches from phase adjustment operation to power generation operation, and the guide vanes of the water turbine begin to open in response to the maximum output signal from the governor unit 2, increasing the power generation output and supplying power to the grid.

Thereafter, the system frequency is raised by the power generation operation of the generator, and when the system frequency drop detection relay 9 returns to normal state, the contact 9 is opened and the auxiliary relay 11 is de-energized.

As a result, the normally open contact 11a2 is opened, and at the same time the NFC bias signal 128 is no longer input, the normally closed contact 11b1 is closed, energizing the auxiliary relay 8 of the governor unit, and the contact 8a in the governor unit 2 is closed. In this case, the contact 8b is opened and the input to the integrator is switched from the generator output 1 to the set value, but the keep relay remains set, so the internal relay sB of the governor unit is not energized. Since the contact s8a is open, the input to the integrator is zero, so the output of the integrator remains the generator output 1. The output of the comparator 13, which detects the deviation between the output of the integrator and the set value of the load setting device 3, determines that the set value of the integrator is set when the keep relay 12 is set and the auxiliary relay 11 is not energized. When it is smaller than the output, the raising auxiliary relay 14 is energized, the contact 14a is closed, the raising command auxiliary relay 17 is energized, and the set value is increased by the electric motor 4. When the set value is larger than the output of the integrator, the lowering auxiliary relay 15 is energized, the contact 15a is closed, the lowering command auxiliary relay 18 is energized, and the set value is decreased by the motor 4. Therefore, when the deviation becomes zero, the auxiliary relay 16 for return of the keep relay is energized, the contact 16 is closed, the keep relay 12 is reset, the contact 12a1 is opened, and the internal relay S8 is de-energized and the load changes. Contact S8a of the rate switching circuit is opened, and the set value of the load setter is input to the integrator via the load change rate switching circuit.

In such a transition from NFC action operation to operation using a load setting device, the input to the integrator is changed to generator output 1 due to the return of the system frequency drop detection relay 9.
The load change rate switching circuit switches to the set value from contact 8.
Since 8a is closed, the output remains at zero, so there is no disturbance to the system.

Further, by the subsequent functions of the comparator 13, the raising auxiliary relay 14, and the lowering auxiliary relay 15, the setting value of the load setter follows the output of the integrator, and when they become equal, the auxiliary relay 16 for return of the keep relay is activated. Since the contact S8a of the load change rate switching circuit is opened and the operation is blindly and dynamically switched to the operation using the load setting device, the burden on the operator can be reduced and a stable switching effect without fear of malfunction can be obtained.

[Effects of the Invention] As described in detail above, according to the present invention, stable power generation can be switched without causing disturbance to the grid.

[Brief explanation of drawings]

FIG. 1(a) is a block diagram of a power generation control device showing an embodiment of the present invention, FIG. 1(b) is a circuit diagram for making a load setting device follow up to the generator output according to an embodiment of the present invention,
FIG. 2 is a block diagram of a conventional power generation control device. 1... Generator output 2... Governor unit 3.
...Load setting device 4...Motor 5...Input switching circuit 6...Load change rate switching circuit 7...Integrator 8...Governor unit auxiliary relay 9.
・Grid frequency detection relay

Claims (1)

[Claims] When multiple water turbine generators connected to a small-scale grid are switched from phase-adjusted operation to power generation operation and power generation control is performed using a load setting device, the system frequency drop detection relay is excited by the operation of this system frequency drop detection relay. The auxiliary relay is energized by the operation of this auxiliary relay, the keep relay is energized by the operation of this auxiliary relay, and in conjunction with this keep relay, the circuit short-circuits the contacts that are held even after the previous system frequency drop detection relay returns, making it possible to switch the load change rate to zero. an integrator provided to the load change rate switching circuit via the normally open contact of the auxiliary relay, and an output of the integrator and input to the load change rate switching circuit through the input switching circuit. a comparator that detects a deviation in the output of a load setting device, a drive device that drives the load setting device so that the deviation becomes zero when the deviation is not zero, and a keep that sets the keep relay to a reset state when the deviation is zero. A power generation control device characterized by comprising an auxiliary relay for returning the relay.