JP2009047087A - Pumping power generation device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pumping power generation device quickly switchable to power generation operation from pumping operation, by using a backflow of water to a pump hydraulic turbine and an electric brake. <P>SOLUTION: This pumping power generation device has a control device 17 for outputting a parallel-off closing command, a field current reducing command, an electric brake operation command, an electric brake releasing command and a power generation operation command. A generator motor 2 is paralleled off from an electric power system 6 by the parallel-off closing command, and a guide vane 11 of the pump hydraulic turbine 1 is closed up to predetermined opening. A field current reducing means reduces a fuel current of the generator motor 2 by the field current reducing command. A switch 7 for the electric brake is closed by the electric brake operation command, and a predetermined field current is supplied from an exciter 9. The exciter 9 stops the field current by the electric brake releasing command. The guide vane 11, a main circuit breaker 3 and the exciter 9 perform operation for operating the generator motor 2 for generating electric power by the power generation operation command. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pumped storage power generation device, and more particularly to a pumped storage power generation device capable of shortening the switching time from pumping operation to power generation operation and a control method thereof.

  Conventionally, switching control of a pumped storage power generator from pumping operation to power generation operation is performed by disconnecting the generator motor from the power system, further closing the input valve and the guide vane, and stopping the pump turbine and generator motor. I was shifting to driving. In this method, after the generator motor is disconnected from the electric power system, the guide vanes are fully closed and the rotation speed is lowered, so that the stop time is long and it takes a long time to shift to the power generation operation.

  As a method for shortening the switching time of a pumped storage power generation device from pumping operation to power generation operation, Patent Document 1 discloses that a generator motor is disconnected from an electric power system, guide vanes are closed, and a guide vane opening degree is predetermined. An example of shifting to power generation operation while maintaining the opening degree is shown.

Japanese Patent Laid-Open No. 60-119381 (6th to 11th lines in the lower left column on page 2, Fig. 3)

  However, since the conventional method for shortening the switching time only uses the back flow of water to the pump turbine, the time for decelerating the pump turbine and the generator motor cannot be shortened sufficiently, and the pumping operation of the pumped-storage power generator can generate power. It was difficult to further reduce the switch to operation.

  The present invention has been made to solve the above-described problems, and a pumped-storage power generation apparatus that can quickly switch from a pumping operation to a power generation operation by using a reverse flow of water to the pump turbine and an electric brake. Aim to get.

  The pumped storage power generator according to the present invention includes a control device that outputs a disconnection closing command, a field current lowering command, an electric brake operation command, an electric brake release command, and a power generation operation command. The generator motor is disconnected from the power system by the disconnection closing command, and the guide vanes of the pump turbine are closed to a predetermined opening degree. In response to the field current lowering command, the field current lowering means lowers the field current of the generator motor. In response to the electric brake operation command, the electric brake switch is closed and a predetermined field current is supplied from the exciter. The excitation device stops the field current in response to the electric brake release command. In accordance with the power generation operation command, the guide vane, the main circuit breaker, and the excitation device perform the operation of causing the generator motor to perform the power generation operation.

  The pumped storage power generator according to the present invention utilizes the backflow of water to the pump turbine, reduces the field current of the generator motor to the field current lowering means, and operates the electric brake to generate the generator motor and the pump turbine. By decelerating, it is possible to quickly switch from pumping operation to power generation operation.

Embodiment 1 FIG.
1 is a diagram showing a configuration of a pumped storage power generator according to Embodiment 1 of the present invention. The pump turbine 1 is connected to a generator motor 2. The generator motor 2 includes an armature winding 2a and a field winding 2b. The armature winding 2 a is connected to the power system 6 through the main circuit breaker 3, the phase inversion disconnector 4, and the main transformer 5. The rotor around which the field winding 2 b is wound is connected to the pump turbine 1.

  The armature winding 2 a is short-circuited by the electric brake switch 7. An excitation device 9 is connected to the field winding 2 b via a field breaker 8. The field winding 2b is connected to a discharge circuit 10 which is a field current reducing means. The discharge circuit 10 has a discharge switch 10a and a short-circuit resistor 10b.

  The pump turbine 1 has a guide vane 11. In the power generation operation of the pumped-storage power generation apparatus, the guide vane 11 supplies the amount of water flowing into the pump turbine 1 through the iron pipe 12, the inlet valve 13 and the connection pipe 14 connected to the upper adjustment pond (not shown). adjust. The water discharged from the pump turbine 1 flows through the suction pipe 15 to the lower adjustment pond (not shown). The governor 16 controls the opening degree of the guide vane 11 and adjusts the rotational speed of the pump turbine 1. The control device 17 controls the main circuit breaker 3, the phase inversion disconnector 4, the electric brake switch 7, the field circuit breaker 8, the discharge circuit 10, and the speed governor 16 to perform pumping operation and power generation operation.

  FIG. 2 is a diagram showing a configuration of the control device of FIG. The control device 17 is an information receiving means 18 that receives an emergency command from an operator or a remote control station and information from various sensors of the pumped storage power generation device. The command received by the information receiving means 18 is decoded by the processing means 19 using the memory 20, and the processing means 19 processes in accordance with the processing procedure stored in the memory 20, and various commands are sent from the command output means 21 to the pumped storage power generator. Is output to the component equipment. The processing unit 19, the memory 20, and the command output unit 21 constitute the command unit corresponding to the command to be output.

  FIG. 3 is a diagram showing the configuration of the excitation device of FIG. The excitation device 9 includes a thyristor rectifier circuit 22 and an ignition control circuit 24. The ignition control circuit 24 is connected (not shown) to the control terminals a1 to a6 of the thyristor 23. The ignition control circuit 24 controls the ignition angle that is the timing of conduction and non-conduction in each thyristor 23 of the thyristor rectifier circuit 22. The command of the control device 17 is received from the terminal Cnt, and the ignition control circuit 24 controls the ignition angle of the thyristor 23 to convert the three-phase alternating current input from the three-phase alternating current terminal In1 into direct current from the Out1 terminal and the Out2 terminal. Outputs field current. The R terminal, the S terminal, and the T terminal are three-phase AC terminals In1 corresponding to the three-phase AC R-phase, S-phase, and T-phase.

  Next, the operation of the pumped storage power generation apparatus will be described. FIG. 4 is a diagram for explaining the operation in the pumped storage power generator according to the first embodiment. Consider a case in which a large-capacity base load supply generator that supplies power to the power grid 6 is suddenly disconnected from the power grid 6 due to an accident when the pumped-storage power generator is performing pumped-storage power generation. This situation is transmitted to the power plant where the pumped-storage generator is installed by signal transmission or the like, and an emergency command for switching from the pumped-up operation to the power generation operation is issued from the operator or the remote control station.

(Disconnection closure procedure)
In response to this emergency command, the control device 17 opens the main circuit breaker 3, disconnects the generator motor 2 from the power system 6, and executes a disconnection closing procedure for closing the guide vane 11 to a predetermined start opening gb1. As described above, the disconnection closing command is output by the disconnection closing command means. The main circuit breaker 3 receives the disconnection closing command and is opened at time t0, the generator motor 2 is disconnected from the power system 6, and the power P of the generator motor 2 is zero. The governor 16 controls the opening degree G of the guide vane 11, and the guide vane 11 is closed at time t1 from the opening degree G to the starting opening degree gb1.

  At this time, since the opening I of the inlet valve 13 remains open and the guide vane 11 does not fully close, the pump turbine 1 continues to rotate in the pumping direction even if the input of the generator motor 2 is lost. Continues in the pumping direction, ie from bottom to top, for a certain period of time. However, since the guide vane 11 is open, the water changes from top to bottom in a short time. Accordingly, the rotational speed N of the main engine composed of the generator motor 2 and the pump turbine 1 is decelerated. The generator motor 2 and the pump turbine 1 are connected to each other at their rotational shafts and rotate at the same rotational speed.

(Field current lowering procedure)
The control device 17 opens the main circuit breaker 3 and then reduces the field current flowing through the field winding 2b of the generator motor 2 during the time t1 when the guide vane 11 becomes the starting opening gb1. A field current decrease command is output by the field current decrease command means so as to execute the decrease procedure. The field breaker 8 and the discharge circuit 10 which are field current lowering means receive a field current lowering command. As shown in operation FCB in FIG. 4, the field breaker 8 is opened, and the discharge circuit 10 closes the discharge switch 10a and connects it to the short-circuit resistor 10b. Therefore, the field current flowing through the field winding 2b is discharged through the short-circuit resistor 10b and decreases. Thereby, the time until the electric brake is operated can be shortened.

  The electric brake is activated when the rotational speed N of the main machine decreases to, for example, about 50% in the pumping direction and the residual voltage of the generator motor 2 becomes substantially zero.

(Electric brake procedure)
The control device 17 detects that the residual voltage of the generator motor 2 has become substantially zero based on a signal from the voltage detector, and then closes the electric brake switch 7 at time t7 and executes the electric brake procedure. An electric brake operation command is output by the electric brake operation command means. As shown in operation ESW in FIG. 4, upon receiving an electric brake operation command, the electric brake switch 7 serving as a disconnector is closed, and the armature winding 2a is short-circuited. As shown in operation FCB in FIG. 4, the field breaker 8 is closed in response to the electric brake operation command. In response to the electric brake operation command, the exciting device 9 controls the control terminals a1 to a6 of the thyristor rectifier circuit 22 to supply a predetermined field current to the field winding 2b.

  When the generator motor 2 passes a predetermined field current, the rotational energy rotating in the pumping direction is consumed as thermal energy in the armature winding 2a. Therefore, by operating the electric brake, the consumption of the rotational energy of the generator motor 2 can be accelerated, and the deceleration time of the rotational speed N of the main engine can be shortened.

  The rotational speed N of the main machine becomes zero at time t2 due to the electric brake and the flow of water from top to bottom, and the main machine rotates in reverse.

(Electric brake release procedure)
The control device 17 opens the electric brake switch 7 after detecting that the rotational speed N of the main engine has become approximately zero based on the signal from the rotational speed detector, and executes the electric brake release procedure so as to execute the electric brake release procedure. An electric brake release command is output by the operation command means. In response to the electric brake release command, the electric brake switch 7 is opened, and the armature winding 2a is separated from the short circuit. The field breaker 8 is opened in response to the electric brake release command. Upon receiving the electric brake release command, the excitation device 9 stops the operation in which the ignition control circuit 24 stops the thyristor rectifier circuit 22 and rectifies the field current.

  Since the opening degree G of the guide vane 11 is the starting opening degree gb1, the pump turbine 1 receives the water flow in the power generation direction, and the main engine rises toward the rated rotational speed in the power generation direction.

(Power generation operation procedure)
After outputting the electric brake release command, the control device 17 outputs the power generation operation command by the power generation operation control means so that the guide vane 11, the main circuit breaker 3, and the excitation device 9 are operated for power generation.

  At time t3, the control device 17 detects that the main engine speed N has reached 80% of the rated speed, for example, based on a signal from the speed detector, and then performs a power generation operation so as to control the guide vane 11. A power generation operation command is output to the governor 16 by the control means.

  In response to the power generation operation command, the governor 16 controls the opening degree G of the guide vane 11, and the opening degree G of the guide vane 11 is throttled from the fully open to the no-load opening degree gb <b> 2. Migrate to

  The control device 17 closes the field breaker 8 and detects excitation control on the excitation device 9 after detecting that the rotation number N of the main engine has reached, for example, 90% based on a signal from the rotation number detector. Then, an excitation control command is output by the power generation operation control means. In response to the excitation control command, the excitation device 9 controls the control terminals a1 to a6 of the thyristor rectifier circuit 22 to supply the field current. Thereafter, the excitation device 9 increases the field current and increases the voltage of the generator motor 2.

  The control device 17 starts the parallel operation at time t4 when it is detected that the output voltage and frequency of the generator motor 2 are rated based on the signal from the voltage detector. After that, the control device 17 detects that the output voltage, frequency, and phase of the generator motor 2 match the voltage, frequency, and phase of the power system 6 based on the signal from the voltage detector, at time t5, which is the main cutoff. The generator 3 is closed and the generator motor 2 is inserted into the power system 6. Furthermore, the governor 16 is caused to open the guide vane 11 rapidly. At time t6, control is performed so that the electric power P becomes the power generation rated output. Thereafter, the control device 17 performs control so as to maintain the power generation operation.

  As described above, the pumped storage power generator according to Embodiment 1 uses a reverse flow of water to the pump turbine 1 unlike the conventional case, reduces the field current of the generator motor 2 to the field current reducing means, Since the brake is applied and the generator motor 2 and the pump turbine 1 are decelerated, the pumping operation can be quickly switched to the power generation operation.

  In addition, although the case where the disconnector was used as the switch 7 for electric brakes was demonstrated, the time until an electric brake is actuated can be further shortened by using a circuit breaker. Since the circuit breaker has the ability to open and close the load, the electric brake can be started without waiting for the residual voltage of the generator motor 2 to become almost zero. Therefore, by advancing the start time of the electric brake, the generator motor 2 and the pump turbine 1 can be decelerated early, and the switching from the pumping operation to the power generation operation can be performed more quickly.

  On the other hand, the disconnector does not have the ability to open and close the load, but is inexpensive. By using a disconnector as the electric brake switch 7, there is an advantage that the pumped-storage power generation apparatus can be made inexpensive.

  In addition, although the example which detects that the rotation speed N of the main machine became zero when outputting the electric brake release command was explained, even if the rotation speed N of the main machine is not zero, the water to the pump turbine is not The main engine rotation speed N may be the rotation speed N that becomes zero in a short time only by backflow. Further, when the electric brake release command is output, the rotation speed N of the main engine may exceed zero and turn in the power generation direction.

Embodiment 2. FIG.
FIG. 5 is a diagram showing a configuration of a pumped storage power generation apparatus according to Embodiment 2 of the present invention. The first embodiment is different from the first embodiment in that the field current is reduced by the ignition control for controlling the ignition angle of the excitation device 9 without using the discharge circuit 10.

  FIG. 6 is a diagram for explaining the operation of the pumped storage power generator according to the second embodiment. The disconnection closing procedure is the same as in the first embodiment, and a description thereof will be omitted.

(Field current lowering procedure)
The control device 17 opens the main circuit breaker 3 and then reduces the field current flowing through the field winding 2b of the generator motor 2 during the time t1 when the guide vane 11 becomes the starting opening gb1. A field current decrease command is output by the field current decrease command means so as to execute the decrease procedure. The exciting device 9 which is also a field current lowering unit receives a field current lowering command. As shown in operation FCB in FIG. 6, the field breaker 8 remains closed.

  As shown in operation SC of FIG. 6, the exciter 9 switches from the pumping operation excitation operation in the period A to the field current decrease operation in the period B in response to the field current decrease instruction. Specifically, the field current is rapidly decreased by controlling the control terminals a1 to a6 of the thyristor rectifier circuit 22 so that the output voltage of the ignition control circuit 24 becomes negative. In the exciter 9, after the field current becomes zero, the ignition control circuit 24 stops the ignition control of the thyristor rectifier circuit 22, and stops the supply of the field current.

  Since the pumped-storage power generation apparatus according to the second embodiment can rapidly reduce the field current by the ignition control, the electric brake can be applied more quickly than in the first embodiment. In addition, there is an advantage that the discharge circuit 10 can be eliminated.

  When the rotational speed N of the main machine decreases to, for example, about 50% in the pumping direction, and the residual voltage of the generator motor 2 becomes almost zero, the electric brake is activated. Subsequent operations are the same as those in the first embodiment.

  As described above, the pumped storage power generation apparatus in the second embodiment rapidly reduces the field current to the same level or more as compared with the first embodiment by the ignition control of the excitation device 9 without using the discharge circuit 10. Can do. Therefore, switching from the pumping operation to the power generation operation can be performed more quickly than in the first embodiment.

  In addition, although Embodiment 1 and 2 demonstrated the case where the armature coil | winding 2a was short-circuited as an electric brake, so that electrical energy may be collect | recovered by the in-house electric power system etc. of the pumped storage power plant which installs a pumped storage power generation apparatus Regenerative braking may be used. There is a merit that electric energy can be recovered by using regenerative braking.

It is a figure which shows the structure of the pumped-storage power generator in Embodiment 1 of this invention. It is a figure which shows the structure of the control apparatus of FIG. It is a figure which shows the structure of the excitation apparatus of FIG. It is a figure explaining the operation | movement in the pumped storage power generator of Embodiment 1. FIG. It is a figure which shows the structure of the pumped-storage power generator in Embodiment 2 of this invention. It is a figure explaining the operation | movement in the pumped storage power generator of Embodiment 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Pump turbine, 2 Generator motor, 2a Armature winding, 2b Field winding, 3 Main circuit breaker, 6 Electric power system, 7 Electric brake switch, 9 Excitation device, 10 Discharge circuit, 11 Guide vane, 17 Control device 22 Thyristor rectifier circuit.

Claims (10)

A pump turbine having a guide vane, a generator motor connected to the pump turbine, a main circuit breaker connecting the generator motor to an electric power system, an excitation device for exciting the generator motor, the guide vane and the main cutoff A pumped-storage power generator comprising a controller that controls the pump and the excitation device to switch from the pumped-up operation to the power-generating operation,
The controller opens the main circuit breaker, disconnects the generator motor from the power system, and outputs a disconnection closing instruction to close the guide vane to a predetermined opening;
Output a field current lowering command to field current lowering means for lowering the field current of the generator motor,
After detecting that the residual voltage of the generator motor has become equal to or lower than a predetermined voltage, an electric brake switch for operating the electric brake on the generator motor is closed and a predetermined field current is supplied from the excitation device. Brake operation command is output,
After the rotational speed of the generator motor has dropped below a predetermined value, the electric brake switch is opened, and an electric brake release command for stopping the field current of the exciter is output.
After the electric brake release command is issued, a power generation operation command is output to the guide vane, the main circuit breaker, and the exciter so as to perform an operation for causing the generator motor to perform a power generation operation. Pumped-storage power generator. The field current lowering means is a discharge circuit for discharging the field current of the field winding of the generator motor,
2. The control device according to claim 1, wherein when the field current is reduced, the control circuit opens a field breaker that connects and disconnects the field winding and the excitation device, and operates the discharge circuit. The pumped storage power generator described. The field current lowering means is the excitation device,
When the control device reduces the field current, the control device causes the thyristor rectifier circuit of the exciter to perform an ignition control for generating a reverse field voltage in order to rapidly reduce the field current. The pumped-storage power generator of Claim 1 characterized by these. The said control apparatus closes the switch for electric brakes, and short-circuits the armature winding of the said generator motor, when operating the said electric brake. Pumped storage power plant. The pumped storage power generator according to any one of claims 1 to 4, wherein the electric brake switch is a circuit breaker. Pumping operation of a pump turbine having a guide vane, a generator motor connected to the pump turbine, a main circuit breaker connecting the generator motor to an electric power system, and an excitation device for exciting the generator motor When switching from power generation operation to
After the disconnection closing procedure of opening the main circuit breaker to disconnect the generator motor from the power system and closing the guide vane to a predetermined opening, the field current of the generator motor is reduced. After performing a current reduction procedure and detecting that the residual voltage of the generator motor has become equal to or lower than a predetermined voltage, the electric brake switch for operating the electric brake on the generator motor is closed and a predetermined field is supplied from the excitation device. An electric brake release procedure for performing an electric brake procedure for supplying a magnetic current and opening the electric brake switch and stopping a field current of the electric brake procedure after the number of revolutions of the generator motor has decreased to a predetermined value or less. The control method of the pumped-storage power generation apparatus which shifted the said pumped-storage power generation apparatus to power generation operation after performing. The field current lowering procedure is to open a field breaker that connects and separates the field winding of the generator motor and the excitation device, and connects to a discharge circuit that discharges the field current of the field winding. The control method of the pumped-storage power generator of Claim 6 characterized by these. The field current lowering procedure includes a thyristor rectifier circuit of the exciter so as to generate a reverse field voltage in order to rapidly reduce the field current of the generator motor when disconnected from the power system. The control method of the pumped-storage power generator according to claim 6, wherein the ignition control is performed on the pump. 9. The method of controlling a pumped storage power generator according to claim 6, wherein the electric brake procedure closes the electric brake switch and short-circuits the armature winding of the generator motor. The method for controlling a pumped storage power generator according to any one of claims 6 to 9, wherein the electric brake switch is a circuit breaker.

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