JP5797512B2 - Variable speed pumped storage power generation control system - Google Patents

Description

  The present invention performs excitation power control by controlling an excitation current supplied by an inverter according to a deviation between a power command value and a power of a generator motor connected to an AC power system and coupled with a pump turbine, The present invention relates to a variable speed pumped storage power generation control system that controls excitation speed by controlling an excitation current supplied by an inverter according to a deviation between a rotation speed and an optimum rotation speed.

A conventional control device for a variable speed pumped storage power generation system in which a runner vane is movable is disclosed in Patent Document 1, for example. A pump turbine capable of adjusting the guide vane opening and the runner vane opening is coupled to the rotor shaft of the generator motor connected to the AC power system.
An inverter that excites AC is connected to the rotor winding of the generator motor, and a converter that converts the power of the AC power system to DC is connected to the DC circuit of the inverter to supply power to the rotor winding.
The optimum guide vane opening, optimum runner vane opening, and rotation speed are calculated according to the power command value and the head, and the guide vane controller controls the guide vane according to the optimum guide vane opening or optimum rotation speed. The runner vane controller controls the runner vanes according to the opening.
By controlling the rotor winding current supplied by the inverter according to the deviation between the power command value and the power, the power of the generator motor is controlled.
Alternatively, the rotational speeds of the generator motor and the pump turbine are controlled by controlling the rotor winding current supplied by the inverter in accordance with the deviation between the optimum rotational speed and the rotational speed.
The rotational speed is controlled by adding the deviation to the optimum guide vane opening and correcting it.

Furthermore, in the conventional control device for variable speed pumped storage power generation, the inverter operates for a long time by limiting the rotation speed command value and controlling the guide vane opening so as to prevent operation at a speed near the synchronous speed. A method for avoiding a rotational speed that cannot be achieved is disclosed (Patent Document 2).
At rotational speeds near the synchronous speed, when the rotor winding current becomes DC, current concentrates on a part of the inverter's power semiconductor elements and rotor windings, and these thermal tolerances are exceeded. There is.

Japanese Patent Laid-Open No. 4-4799 (Figures and Description) Japanese Patent No. 3853426 (figure and description thereof)

In the control device of the variable speed pumped storage power generation system that adjusts the rotational speed of the pump turbine by the conventional guide vane opening and runner vane opening, the device may be damaged by staying in the vicinity of the synchronous speed for a long time.
Further, in the variable speed pumped storage power generation system that adjusts the rotational speed of the pump turbine by the guide vane opening, the power followability may be deteriorated by fixing the rotational speed command value.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to eliminate the possibility of causing damage to the apparatus and to further improve the reliability of the variable speed pumped storage power generation control system.

  The variable speed pumped storage power generation control system according to the present invention controls the excitation current supplied by the inverter according to the deviation between the power command value and the power of the generator motor connected to the AC power system and coupled with the pump turbine. In a variable speed pumped storage power generation control system that performs control and performs excitation speed control by controlling the excitation current supplied by the inverter according to the deviation between the rotation speed of the generator motor and the optimum rotation speed, the slip frequency is near zero And a determination function unit that determines that the slip frequency has deviated from near zero. When the determination function unit determines that the slip frequency is near zero, the excitation power control is changed to the excitation speed control. When the determination function unit determines that the slip frequency has departed from around 0, the excitation speed control is returned to the excitation power control. .

  The present invention performs excitation power control by controlling an excitation current supplied by an inverter according to a deviation between a power command value and a power of a generator motor connected to an AC power system and coupled with a pump turbine, In a variable speed pumped storage power generation control system that performs excitation speed control by controlling an excitation current supplied by an inverter according to a deviation between a rotation speed and an optimum rotation speed, it is determined that a slip frequency is near 0 and the slip frequency is Is determined to have left the vicinity of 0. When the determination function unit determines that the slip frequency is near 0, the excitation power control is switched to the excitation speed control, and the determination function unit When it is determined that the slip frequency has departed from around 0, the excitation speed control is returned to the excitation power control, so that the possibility of causing damage to the device is eliminated and variable. There is an effect that it is possible to further improve the reliability of pumped storage control system.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates Embodiment 1 of this invention, and is a block diagram which shows the structure of a variable speed pumped-storage power generation control system. It is a figure which illustrates Embodiment 2 of this invention, and is a block diagram which shows the structure of a variable speed pumped-storage power generation control system. It is a figure which illustrates Embodiment 3 of this invention, and is a block diagram which shows the structure of the forbidden band passage controller (determination function part) in FIG. 1 and FIG.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an example of a system configuration of a variable speed pumped-storage power generation control system according to Embodiment 1 of the present invention.
The power system 1 is connected to the stator winding of the generator motor 2 and the input of the AC excitation device 4, and the rotor winding of the generator motor 2 is connected to the output of the AC excitation device 4.
A pump turbine 3 and a rotational speed detector 8 are coupled to the rotor shaft of the generator motor 2.
In the power system 1, a voltage detector 6 and a current detector 5 are installed, and outputs from these detectors are input to a power and frequency detector 7.
Further, the outputs of the head detector 9 and the power command value setter 10 are input to the optimum value setter 11.

The forbidden band controller 12 serving as a determination function unit includes an optimum rotation speed Nopt output from the optimum value setter 11, a rotation speed N output from the rotation speed detector 8, and a power command value P output from the power command value setter. * The power P and the frequency f output from the power and frequency detector 7 are input.
The excitation speed controller 14 is the rotation speed command value N * output from the forbidden band passage controller, the excitation speed control permission signal ExANRon and the rotation speed N output from the rotation speed detector 8, and the current command value Iq * of the AC excitation device 4. Is input and the control signal Iqn * is output.

The excitation power controller 13 includes a power command value P * output from the power command value setter 10, an excitation power control permission signal ExAPRon output from the forbidden band pass controller, an effective power P output from the power and frequency detector 7, and an alternating current. The current command value Iq * of the excitation device 4 is input, and the control signal Iqp * is output.
The switch 15 receives a control signal Iqp * output from the excitation power control 13, a control signal Iqn * output from the excitation speed control, and an excitation power control permission signal ExAPRon output from the forbidden band controller 12. The current command value Iq * of the device 4 is output and sent to the AC excitation device 4.

The rotational speed controller 16 includes a rotational speed command value N * output from the forbidden band passage controller 12, a rotational speed control hold signal ANRhold, a rotational speed N output from the rotational speed detector 8, and an optimum runner vane output from the optimum value setter. The opening RVopt is input, and a runner vane opening command value RV * is output and sent to the runner vane opening controller 17, which gives the runner vane opening RVO of the pump turbine.
The guide vane opening controller inputs the optimum guide vane opening GVopt output from the optimum value setter 11 as its command value GV * and gives the guide vane opening GVO of the pump turbine 3.

Next, the operation will be described.
The generator motor 2 is excited with an alternating current having a difference frequency fs = f−fr between the frequency f of the power system 1, the rotation speed N of the generator motor 2, and the rotation frequency fr proportional to the number of pole pairs of the generator motor. The difference frequency fs is also called a slip frequency, and the AC excitation device 4 controls the output frequency to the slip frequency fs and supplies a current to the rotor winding of the generator motor 2.
The magnitude and phase of the current supplied to the generator motor 2 by the AC exciter 4 is controlled according to the current command value Iq *. As a result, Iq * is the power generated in the stator winding of the generator motor 2. Proportional value.

The stator winding of the generator motor 2 is connected to the power system 1 and receives power from the power system 1.
The input of the AC excitation device 4 is connected to the power system 1 for power conversion. For power conversion, an inverter circuit and converter circuit that performs frequency conversion via a DC circuit and a cycloconverter that directly converts the frequency are applied, and by controlling the output current of the slip frequency at high speed, The stator power of the electric motor 2 is controlled at high speed.

  The pump turbine 3 connected to the generator motor 2 is operated at an optimum operating point of the pump turbine 3 by controlling the input as a pump by adjusting the guide vane and the runner vane.

The power received from the power system 1 is detected by detecting the active power from the voltage detector 6 and the current detector 5 with the power and frequency detector 7.
Further, the frequency of the power system 1 is detected by the voltage detector 6 by the power and frequency detector 7, but can be easily detected by, for example, a PLL.

Although not shown in FIG. 1, the head detector 9 calculates a head H according to the water level of the lower adjustment pond that stores the water pumped up by the pump turbine 3 and the upper adjustment pond to which the pump turbine 3 is pumped up.
The power command value setter 10 sets the power received from the power system 1 and outputs it as a power command value P *.
The optimum value set value 11 generates an optimum rotational speed Nopt, an optimum guide vane opening GVopt, and an optimum runner vane opening RVopt according to the head H, the electric power command value P *, and the characteristics of the pump turbine 3. . These optimum values can be easily generated by storing them in a memory as a function or numerical table of the head H and the power command value P *.

The forbidden band pass controller 12 obtains the slip frequency fr from the rotation speed N and the frequency f of the power system, and if it is determined that it is not near 0 Hz, the excitation speed control permission signal ExANRon and the rotation speed control hold signal are set to 0. The power control permission signal ExAPRon is set to 1 respectively. The rotational speed command value N * is set to the optimum rotational speed Nopt and output.
When the excitation power control permission signal ExAPRon is 1, the excitation power controller 13 uses the power command value P * and the power P
A signal obtained by amplifying the deviation is output as a control signal Iqp *. When the excitation power control permission signal ExAPRon is 0, the current command value Iq * is output as Iqp *.

When the excitation speed control permission signal ExANRon receives 0, the excitation speed controller 14 receives the current command value Iq *.
Is output as a control signal Iqn *. When the excitation speed control permission signal ExANRon is 1, by outputting a signal obtained by amplifying the deviation between the rotational speed command value N * and the rotational speed N as the control signal Iqn *,
The electric power generated by the generator motor 2 is adjusted at a high speed to control the rotation speed.
The switch 15 switches between the two inputs according to the control signal c. When 1 is input to the control signal c, the control signal c is set to Iq * as the control signal Iqp * output from the excitation power controller 13. When 0 is input to, the control signal Iqn * output from the excitation speed controller 14 is output as Iq *. As a result, when the excitation power control permission signal ExAPRon is 1, the current of the AC excitation device 4 is controlled according to the output of the excitation power controller 13, and the power generated in the stator of the generator motor 2 is adjusted. The power command value P * and the value of the power P substantially match, and the received power from the AC power 1 is controlled.

The rotational speed controller 16 adds a signal obtained by amplifying the deviation between the rotational speed command value N * and the rotational speed N so as to correct the optimum runner vane opening degree RVopt, and outputs the runner vane opening instruction value RV *. When the rotational speed control hold signal ANRhold is 1, the runner vane opening command value RV * is held at a value before the rotational speed control hold signal ANRhold becomes 1.
When the rotational speed control hold signal ANRhold is 0, a signal corresponding to the rotational speed deviation is sent to the runner vane opening controller 17, and the runner vane opening controller determines the runner vane opening RVO of the pump turbine 3 as its command value RV *. Control to be Thereby, the input of the pump turbine is adjusted and the rotational speed is controlled. On the other hand, the guide vane opening controller 18 uses the optimum guide vane opening GVopt as the command value GV *, and controls the guide vane opening GVO of the pump turbine 3 to be the command value GV *, so that the optimum operation operating point is obtained. Get.

When the forbidden band pass controller 12 determines that the slip frequency fr is near 0 Hz, the excitation power control permission signal ExAPRon is set to 0, and the excitation speed control permission signal ExANRon and the rotation speed control hold signal ANRhold are set to 1. The rotational speed command value N * is set to a predetermined fixed value that does not cause the slip frequency to be near zero. As a result, the runner vane opening degree is fixed, the rotational speed N is controlled by the excitation speed controller 14, the rotational speed command value N * is controlled at a high speed, and the slip frequency is controlled to depart from near zero.

The excitation speed controller 14 adjusts the output current of the AC excitation device 4, and as a result, the electric power generated by the generator motor 2 is adjusted. When the input power becomes larger than the output of the pump turbine 3, the acceleration is accelerated. The rotational speed is controlled by operating as described above. Then, it is determined that the slip frequency has departed from near 0 Hz, and the excitation power control permission signal ExAPRon is set to 1, and the excitation speed control permission signal ExANRon and the rotation speed control hold signal are set to 0.
By this operation, the rotational speed N is controlled by adjusting the runner vane opening at the operating point where the slip frequency is away from near 0, and at the same time, the power P is controlled by the excitation power controller 13 to the power command value P *. It is driven to almost coincide. Then, it is determined that the optimum rotation speed Nopt substantially matches the fixed N *, and that the power P substantially matches the power command value P *, and the rotation speed command value N * is set to the optimum rotation speed Nopt. return.

When operating in this way and the slip frequency is near 0 Hz, it switches to excitation speed control that allows higher speed control compared to rotational speed control by adjusting the runner vane opening, and immediately leaves 0 Hz with minimal power fluctuations. Thus, it is possible to leave from an operating point that cannot be operated for a long time, and after leaving, it is possible to switch to high-speed excitation power control and control to a desired power.
Furthermore, when the optimum rotation speed Nopt changes to a rotation speed that does not become 0 Hz, it is possible to return to the operation at the optimum rotation speed, and the variable speed pumped storage power generation system can be operated efficiently.
In a system that adjusts the input of a pump turbine only by guide vanes, it is difficult to follow the power command value because the active power is almost determined when the rotational speed is set. In the variable speed pumped storage power generation system according to the present invention, The following characteristic to the power command value is advantageous.

The first embodiment described above generally includes a generator motor in which a stator winding is connected to an electric power system, an AC exciter that supplies current to the rotor winding using the electric power system as an input, and an electric generator motor. A pump turbine connected to the rotating shaft and capable of adjusting the guide vane opening and the runner vane opening, a rotating speed detecting means for detecting the rotating speed of the rotating shaft of the generator motor, and an electric power for detecting the power and frequency of the power system. And a frequency detection means, a power command value setting means for giving a power command value of the power system, a head detection means for detecting a head, an optimum rotational speed and an optimum guide vane opening according to the power command value and the head An optimum value setting means for setting the optimum runner vane opening, an excitation power control means for generating a current command value for the AC exciter according to the power command value and the power of the power system, and a rotational speed Excitation speed control means for generating a current command for the AC exciter from the command value and the rotation speed, and guide vane opening from the rotation speed command value and the rotation speed and the optimum guide vane opening or the optimum runner vane opening. A rotational speed control means for generating a degree command value or a runner vane opening command value, a guide vane control means for controlling a guide vane according to the guide vane opening command value, and a runner vane according to the runner vane opening command value In the variable speed pumped storage power generation system including the runner vane control means for controlling, the rotational speed command value is set to the optimum rotational speed, the current command value of the previous AC exciter is operated by the excitation power control, and the power system Calculate the slip frequency from the frequency and the rotation speed, determine that the slip frequency is near 0, The output of the rotation speed control means is fixed, the current command value of the AC exciter is switched to the output of the excitation speed control means, and the rotation speed command value is set to a fixed value so that the slip frequency leaves near 0. A variable-speed pumped-storage power generation control system that determines that the slip frequency has deviated from near 0, operates the rotational speed control means, and returns the current command value to the output of the excitation power control means. In a variable speed pumped storage power generation system where the input / output of the motor is controlled by the guide vane and runner vane, the AC exciter and generator motor can be operated without staying near the slip frequency 0 where the AC exciter and generator motor cannot be operated for a long time. It is possible to follow the command value. Further, it is determined that the slip frequency is not near 0, the power follows the power command value, and the optimum rotation speed is close to a fixed value of the rotation speed command, and the rotation speed command value is The speed is restored and the variable speed pumped storage power generation system can be operated as efficiently as possible.

Embodiment 2. FIG.
In the pump operation configuration of FIG. 1, the output of the rotational speed controller 8 is the runner vane opening command RV *.
However, as shown in FIG. 2, during the power generation operation, the output of the rotational speed controller 8 is a guide vane opening command GV *. Further, the rotational speed command N *, the rotational speed N, and the optimum guide vane opening GVopt are connected as inputs.

When it is determined that the forbidden band pass control is not near the slip frequency 0 Hz, the operation of the excitation power controller 13 is the same as in FIG. 1, but the power generated in the power system 1 is controlled. Then, the rotation speed controller 8 adds a signal obtained by amplifying the deviation between the rotation speed command value N * and the rotation speed N to the optimum guide vane opening GVopt, and outputs the guide vane opening command value GV *. Then, the guide vane opening controller 17 controls the rotational speed N to be controlled to a desired guide vane opening. The runner vane opening controller 18 receives the optimum runner vane opening RVopt as the runner vane opening command value RV * and controls the runner vane opening to an optimum position.

When the forbidden band pass control determines that the slip frequency is near 0 Hz, the excitation power controller 13 is switched to the excitation speed controller 14 and the current command of the AC exciter 4 is adjusted so that the rotational speed is quickly separated from near 0 Hz. Although it is the same as that of FIG. 1, the rotational speed controller 8 fixes the guide vane opening degree command value GV *. Then, it is determined that the slip frequency has departed from around 0 Hz, the operation of the excitation power controller 13 is restored, and the output of the rotational speed controller 16 is also controlled according to the rotational speed deviation and the optimum guide vane opening. The Then, it is determined that the optimum rotation speed Nopt substantially matches the rotation speed command N *, and that the power P substantially matches the power command value P *, and the rotation speed command N * is changed to the optimum rotation speed Nopt. The returning operation is the same as in FIG.

In this way, when the slip frequency is close to 0 Hz even during power generation operation, it switches to excitation speed control that allows higher speed control compared to rotational speed control by adjusting the guide vane opening, and minimizes power consumption. It is possible to leave immediately from near 0 Hz due to fluctuations and leave from an operating point where it cannot be operated for a long time, and after leaving, it is possible to switch to high-speed excitation power control and control to a desired power. Furthermore, when the optimum rotational speed Nopt changes to a speed that does not become 0 Hz, it is possible to return to the operation at the optimum rotational speed, and the variable speed pumped storage power generation system can be operated efficiently.

Embodiment 3 FIG.
FIG. 3 is a block diagram showing an example of the internal configuration of the forbidden band passage controller (determination function unit) 12 of the variable speed pumped storage power generation control system of the present invention. The configuration other than the forbidden band pass control 12 is the same as that of the first embodiment shown in the configuration diagram of FIG. 1 or the second embodiment shown in the configuration diagram of FIG.

The rotation speed N is multiplied by the gain 101a, and is subtracted from the system frequency f by the adder / subtractor 102a. The output of the adder / subtractor 102a is input to the absolute value calculator 104a and the polarity discriminator 105. The output of the absolute value calculator 104a is input to the comparator 106a.
11b is input to the set side. The output of the flip-flop 111a and the output of the polarity discriminator 105 are input to the output holder 107a, and the output and the output of the polarity discriminator 105 are multiplied by the multiplier 10.
Multiply by 3a and input to the comparator 106b.

The logical inversion of the output of the comparator 106a and the output of the comparator 106b are input to the logical product operator 108a, and the output is input to the reset side of the flip-flop 111b via the on-delay timer 110a. The logical inversion of the output of the flip-flop 111a and the output of the flip-flop 111b is input to the logical product operator 108h, and the output is input to the set side of the flip-flop 111c. The outputs of the flip-flops 111a and 111b are input to the logical product operator 108i, and the output thereof is output as the rotational speed control hold signal ANRhold and simultaneously as the excitation speed control permission signal ExANRon. The output of the logic operation unit 108i is further output as an excitation power control permission signal ExAPRon via the logic inverter 113.

  The output of the polarity discriminator 105 is multiplied by the set value Smin + ΔS by the multiplier 103b and added to the system frequency f by the adder / subtractor 102d. The output of the adder / subtractor 102d is input to an output holder, and the output becomes one input of the switch 112 via the gain 101b. The optimum rotational speed Nopt is input to the other input of the switch 112, the output of the flip-flop 111a becomes a switching signal of the switch 112, and the output is output as the rotational speed command value N *.

The power command value P * and the power P are calculated by the adder / subtractor 102e and input to the comparator 106c via the absolute value calculator 104b. The output of the output holder 107a is input to the comparator 106d. The system frequency f and the set value Smin are added by the adder / subtractor 102b and subtracted by the adder / subtractor 102c, and the respective outputs are input to the comparators 106e and 106g and the comparators 106f and 106h. The optimum rotational speed Nopt via the gain 101c is input to the other input of the comparators 106e, 106f, 106g, and 106h.

The output of the comparator 106d and the output of the comparator 106e are input to the AND operator 108b, the logical inversion of the output of the comparator 106d and the output of the comparator 106f are input to the AND operator 108c. The output is input to the logical sum calculator 109a.
The logical inversion of the output of the comparator 106d and the output of the comparator 106g are input to the AND operator 108d, the output of the comparator 106d and the output of the comparator 106h are input to the AND operator 108e, and the outputs of these AND operators Is input to the logical sum calculator 109b.

The logical inversion of the output of the flip-flop 111c and the output of the comparator 106a, the output of the comparator 106c, and the output of the OR operator 109a are input to the AND operator, and the on-delay timer 11
It is input to the logical sum calculator 109c via 0b. The output of the logical sum operator 109b and the output of the flip-flop 111a are input to the logical product operator 108f, and the on-delay timer 110c.
Is input to the logical sum calculator 109c, and the output becomes the input on the reset side of the flip-flops 111a and 111c.

Next, the operation will be described.
The rotational frequency N is multiplied by the gain 101a to calculate the rotational frequency fr, and the difference is calculated from the system frequency f by the adder / subtractor 102a to obtain the slip frequency fs. The slip frequency is positive when the rotational speed is lower than the synchronous speed and negative when the rotational speed is higher.

The absolute value calculator 104a calculates the absolute value of the slip frequency and sets a preset set value Smin.
Compare with The comparator 106a outputs 1 when the absolute value of the slip frequency is smaller than the set value Smin, and outputs 0 otherwise, and determines that the slip frequency is in the vicinity of 0. Then, the determination result is input to the set side of the flip-flop 111a, and the output of the flip-flop 111a is changed from 0 to 1. At the same time, the output is changed from 0 to 1 by inputting to the set side of the flip-flop 111b, and the output of the AND operator 108i is changed from 0 to 1.

The output of the logical product operator 108i becomes a rotation speed control hold signal ANRhold and an excitation speed control permission signal ExANRon signal. Further, the logical inverter 113 logically inverts the logical product operator 108i and changes from 1 to 0. The excitation power control permission signal is changed from 1 to 0 and excitation power control is stopped. The output of the flip-flop 111a is input to the control signal c of the switch 112. When this is 0, the optimum rotational speed Nopt is output, but when it changes to 1, the output is switched to the output of the gain 101b.

The polarity discriminator outputs 1 when the slip frequency is positive, and -1 when it is negative (functions by outputting either when it is 0), and the multiplier 103b multiplies the set value Smin + ΔS. When the slip frequency is positive, the value is higher by Smin + ΔS than the system frequency, and when the slip frequency is negative, the value is lower by Smin + ΔS than the system frequency. It is calculated at 102d.

The output holder 107b holds the input value when the output of the flip-flop 111a changes from 0 to 1 as an output until the value of the flip-flop 111a becomes 0. Then, the gain 101b is multiplied by a gain for converting the frequency to the rotation speed. Therefore, when it is determined that the slip frequency is near 0, the output of the flip-flop 111a changes from 0 to 1,
The rotational speed command value N * is switched from the optimal rotational speed Nopt to the synchronous speed command value of ± (Smin + ΔS) from the synchronous speed corresponding to the system frequency f until the output of the flip-flop 111a changes from 1 to 0. The command value N * is held. Smin is a determination value for determining that the slip frequency is near 0, and the operation is performed at a slip frequency that is separated by a margin ΔS.

Next, the reset operation of the flip-flop 111b will be described.
The output of the polarity discriminator 105 is held by the output holder 107a while the output of the flip-flop 111a is 1. The value is the output value of the polarity discriminator 105 when the flip-flop 111a changes from 0 to 1. This corresponds to the polarity of the slip frequency when the comparator 106a determines that the slip frequency is around 0 Hz.

Then, the output of the output holder 107a and the output of the polarity discriminator 105 are multiplied by the multiplier 103a, and the comparator 106b outputs 1 when 0 or less, and 0 otherwise. By this operation, the comparator 106b determines that the polarity of the slip frequency is opposite to the polarity at the time when the slip frequency near zero is determined.

  Further, the logical inversion of the output of the comparator 106a that determines the vicinity of slip 0 and the logical product of the output of the comparator 106b are calculated by the logical product calculator 108a, so that the slip frequency is not close to 0 and the advance By judging the slip frequency and polarity, it is judged that it has exceeded 0.

Further, the on-delay timer 110a operates so that the output changes from 0 to 1 when the predetermined time 1 continues and immediately becomes 0 when the input becomes 0, so that the slip frequency exceeds 0 and leaves the vicinity of 0. By confirming that this has been done for a predetermined period, it is possible to reliably determine that the slip frequency has exceeded zero. The flip-flop 111b is reset by the output of the on-delay timer 110a, and the AND operator 108i changes its output from 1 to 0.
By this operation, the rotation speed control hold signal ANRhold and the excitation speed control permission signal ExANRon are changed from 1 to 0, and the excitation power control permission signal ExAPRon is changed from 0 to 1, so that the control operation is switched.

When the output of the flip-flop 111b changes from 1 to 0, the flip-flop 111a becomes 1
Therefore, the AND operator 108h changes its output from 0 to 1. As a result, the flip-flop 111c is set and its output changes from 0 to 1.

The output of the flip-flop 111c is input to the logical product operator 108g, and this output is supplied to the flip-flop 111a via the on-delay timer 110b and the logical sum operator 109c.
111c are reset, all the flip-flops are reset, the forbidden band pass control 12 is reset, and the rotational speed command value N * is also returned to the normal control of the optimal rotational speed Nopt.

The determination to return to the normal control is based on the other inputs of the AND operator 108g. First, the fact that the slip frequency is not near 0 is input as the logical inversion of the output of the comparator 106a. Then, the difference between the power command value P * and the power P is calculated by the adder / subtractor 102e, and the absolute value is calculated by the absolute value calculator 104b. This is the magnitude of the power deviation. When the magnitude is smaller than the set value ΔP, the comparator 106c changes from 0 to 1, and is input to the AND operator 108g.

Further, the set value Smin is added to the system frequency f by the adder / subtractor 102b and subtracted by the 102c, thereby calculating the rotation frequency for determining the vicinity of 0 of the slip frequency. And optimum rotation speed Nopt
Is converted to the optimum rotation frequency via the gain 101c, and the comparator 106e determines that the optimum rotation frequency is greater than the rotation frequency f + Smin for determining the vicinity of slip 0, and the comparator 106f determines that the optimum rotation frequency is near 0. It is determined that the rotation frequency is smaller than f-Smin.

The output of the comparator 106d that semi-determines that the polarity of the slip frequency is positive when it is determined that the slip frequency is close to 0 and the output of the comparator 106e are ANDed by the AND operator 108b. To determine that the previous slip frequency is positive, that is, the previous rotation frequency is f-Smin and the current rotation frequency is greater than f + Smin.

Further, the logical inversion of the output of the comparator 106f and the output of the comparator 106d is performed by a logical product operator 108c.
To determine that the prior rotation frequency is f + Smin and the current rotation frequency is f−Smin.

The outputs of these two logical product operators 108b and 108c are input to a logical sum operator 109a to calculate a logical sum. When the prior rotation frequency is f-Smin, the slip frequency is positive, and the rotation speed command value is set to a value corresponding to f + Smin + ΔS.
Conversely, when the prior rotation frequency is f + Smin, the slip frequency is negative, and the rotation speed command value is set to a value corresponding to f− (Smin + ΔS).

Therefore, in the logical sum 109a, it is determined whether the optimum rotational speed has approached the vicinity of the rotational speed command value fixed by the switch 112 or is separated by the same slip frequency polarity. In other words, the AND operator 108g determines that the slip frequency is not near 0, the power follows the command value, and the optimum rotation speed approaches the fixed rotation speed command value or is separated by the same slip frequency polarity. doing. The on-delay timer 110b confirms that the condition has continued for a predetermined time.

Another signal is input to the OR operation unit 109c that resets the flip-flops 111a and 111c.
The comparator 106g determines that the optimum rotation frequency is higher than f + Smin.
The comparator 106h determines that the optimum rotation frequency is smaller than f-Smin.

Then, when the advance slip frequency is negative, that is, when the advance rotation frequency is f + Smin and the optimum rotation frequency is greater than f + Smin, the AND operation unit 108d changes from 0 to 1, and the advance slip frequency is When the positive rotation frequency is f-Smin and the optimum rotation frequency is smaller than f-Smin, the logical product operator 108e changes from 0 to 1.

Then, the logical sum of the outputs of these two logical product computing units 108d and 108e is computed by the logical sum computing unit 109b. The output of the logical sum calculator 109b determines that the optimal rotation frequency is in the same direction as the previous slip frequency.
Then, the logical product is calculated by the AND operation unit 108f with the output of the flip-flop 111a, and it is determined that the optimum rotation speed is reversed without exceeding the forbidden band even though the forbidden band passing control is being performed. .
When the state continues for a predetermined period by the on-delay timer 110c, a confirmation signal is output and used as an input to the logical sum calculator 109c.

With this operation, the slip frequency becomes once near zero, and the forbidden band pass control operates to set the rotation speed command value N * to a fixed value different from the optimum rotation speed Nopt, but the optimum rotation speed Nopt is It is determined that the distance is away from the fixed value, and the forbidden band pass control can be reset once.
As a result, it is possible to follow a sudden change in the optimum rotational speed Nopt caused by a sudden change in the power command value P *. When the on-delay timer 110c is activated and the forbidden band pass control is reset, it passes again near the slip frequency 0, and the flip-flop 111a is set once again to perform a predetermined operation. Since the rotational speed Nopt is far from the fixed rotational speed command value, the comparator 106e or 106f operates, the forbidden band passing control is finished, and the rotational speed command value N * may return to the optimum rotational speed Nopt. it can.

As described above, when the slip frequency is near 0 Hz, the power is switched to excitation speed control, which enables high-speed control compared to rotational speed control by adjusting the runner vane opening or guide vane opening. It is possible to leave immediately from near 0 Hz due to fluctuations and leave from an operating point where it cannot be operated for a long time, and after leaving, it is possible to switch to high-speed excitation power control and control to a desired power.
Furthermore, even if the optimum rotation speed Nopt changes suddenly, it is possible to return to the operation at the optimum rotation speed, and the variable speed pumped storage power generation system can be operated efficiently.

In the third embodiment, generally, it is determined that the slip frequency is not near 0 and the optimum rotation speed is away from the fixed value of the rotation speed command, and the current command value is determined by the excitation power control means. The output is used to return the rotational speed command value to the optimum rotational speed, and the variable speed pumped storage power generation system can be operated efficiently even when the optimum rotational speed changes suddenly.

In the present invention, each embodiment can be appropriately modified or omitted within the scope of the invention.
In addition, in each figure, the same code | symbol shows the same or equivalent part.

1 power system, 2 generator motor, 3 pump turbine, 4 AC exciter,
5 Current detector, 6 Voltage detector, 7 Power and frequency detector,
8 Rotational speed detector, 9 Head detector, 10 Power command value setter,
11 optimum value setting device, 12 forbidden band pass controller (determination function part),
13 Excitation power controller, 14 Excitation speed controller, 15 Switch,
16 rotational speed controller, 17 runner vane opening controller,
18 Guide vane opening controller.

Claims (3)

The excitation power is controlled by controlling the excitation current supplied by the inverter according to the deviation between the power of the generator motor connected to the AC power system and the pump turbine connected to the power command value, and the rotation speed of the generator motor is optimized. In a variable speed pumped storage power generation control system that controls excitation speed by controlling the excitation current supplied by the inverter according to the deviation from the rotation speed,
Excitation power control means for generating the current command value of the AC exciter according to the power command value and the power of the power system and performing the excitation power control, and the current of the AC exciter from the rotation speed command value and the rotation speed An excitation speed control means for generating a command and performing the excitation speed control;
A determination function unit for determining that the slip frequency is near 0 and determining that the slip frequency is close to 0; and when the determination function unit determines that the slip frequency is near 0, the excitation power switching Rutotomoni the slip frequency in the excitation speed control from the control is a fixed value the rotational speed command value so as to leave the vicinity of 0, the excitation and the determination function unit determines that the slip frequency has left the vicinity of 0 A variable-speed pumped-storage power generation control system characterized by returning from the speed control to the excitation power control.   The variable speed pumped storage power generation control system according to claim 1, wherein the opening degree of both the guide vane and the runner vane of the pump turbine is controllable. 2. The variable speed pumped storage power generation control system according to claim 1 , wherein it is determined that the slip frequency is not near zero and the optimum rotational speed is away from a fixed value of the rotational speed command, and the slip frequency is near zero. The variable speed pumped-water power generation control is characterized in that when the optimum rotational speed is not equal to the fixed value of the rotational speed command, the excitation power control is restored and the rotational speed command value is restored to the optimum rotational speed. system.

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