JPH05113171A - Speed regulation control device of water turbine - Google Patents

Abstract

PURPOSE:To carry out speed regulation control without any unnecessary operation such as reduction of rotational speed of the water turbine beyond its rated level, the secondary increase of rotational speed, and the like, whenever rapid load fluctuation such as load interruption may be generated. CONSTITUTION:When rapid load fluctuation such as load interruption is generated a time equal to a time until the increased rotational speed of a water turbine is returned to its rated rotational speed is found out by a holding time calculator 16 from the servo opening degree of a servo motor 11. A non-load opening bias alpha is outputted for only the calculated time from a one shot circuit 9 to an adder 3c instead of a signal from an integrator 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed governor control device for a hydraulic turbine that controls the rotational speed of the hydraulic turbine to a specified rotational speed in response to load fluctuations in a hydraulic power plant using a hydraulic turbine generator having a small moment of inertia.

[0002]

2. Description of the Related Art Generally, a turbine generator of a hydroelectric power plant is connected to a power system and operates in parallel with generators of many other power plants, and the generators in parallel must be synchronized with each other. I won't. Therefore, the generator is provided with a speed control device for controlling the target frequency.

That is, when the load of the generator is constant, the turbine is operated at a specified number of revolutions, but when load variation occurs and the number of revolutions of the turbine changes due to imbalance with the output, the servo motor servo opens. To control the speed of the water turbine to the specified speed. Hereinafter, a conventional speed control device will be described with reference to the configuration diagram of FIG. The speed detector 1 detects the rotation speed of a water turbine (not shown) and outputs a speed detection signal S1 proportional to this rotation speed. The speed setter 2 sets in advance the number of rotations of the water turbine according to the operation, and outputs a speed setting signal S2 proportional to this number of rotations. The adder 3a uses the speed detection signal S
1 and the speed setting signal S2 are added to calculate the speed deviation signal S3.
Is output. The adder 3b performs an addition operation on the speed deviation signal S3 and the drooping load deviation signal S4 (which will be described later in detail) and outputs a control deviation signal S5. The proportional unit 4 processes the control deviation signal S5 according to the proportional characteristic and outputs it to the adder 3c. The differentiator 5 processes the control deviation signal S5 according to the differential characteristic and outputs it to the adder 3c. The integrator 6 has a contact 7a that is closed during normal operation (during operation with a minute load change).
The control deviation signal S5 is processed and output in accordance with the integration characteristic. The contact 8 is in a closed state when the load fluctuates rapidly (for example, the load is cut off).

The one-shot circuit 9 causes the contact 8 to be closed for a certain period of time when the contact 8 is closed, and the contact 7b in the open state to be closed for a certain period of time. Instead of the signal output from the integrator 6, α is output to the adder 3c. The adder 3d is the adder 3
The opening degree command signal S6 and the opening degree signal S7 (which will be described later in detail) output from c are subjected to addition calculation, and the opening degree deviation signal S is calculated.
8 is output. The current / mechanical converter 10 has an opening deviation signal S
8 is converted into a signal for controlling the servo opening of the servo motor 11. The position detector 12 detects the servo opening of the servo motor 11 and outputs an opening signal S7 according to the servo opening.

The adder 3e is a load setter 13 for setting a target load when the generators are operating in parallel with the system.
The load setting signal S9 and the opening degree signal S7 output from the above are added and calculated to output a load deviation signal S10.

The droop rate setter 14 processes the load deviation signal S10 according to a preset droop rate, and outputs a droop load deviation signal S4 via a contact 15 which is closed only when a sudden load change occurs. Next, the operation of the conventional speed control device will be described.

During normal operation (operation with a slight load change), the speed detection signal S1 detected by the speed detector 1 and the speed setting signal S2 set by the speed setting device 2 are set by the adder 3a. The deviation signal S3 is output. Since the contact 15 is in the open state, only the speed deviation signal S3 is input to the adder 3b and the control deviation signal S5 is output. The control deviation signal S5 is supplied to the proportional unit 4, the differentiator 5, and the integrator 6. It is input, processed according to each characteristic, and output to the adder 3c. Then, the adder 3d outputs the open degree deviation signal S8 between the open degree command signal S6 output from the adder 3c and the open degree signal S7 output from the position detector 12, and the open degree deviation signal S8 is the current. / Servo motor 11 with mechanical converter 10
Is converted into a signal for controlling the servo opening degree. With the above operation, the rotational speed of the water turbine can be controlled to the rated rotational speed with respect to a minute load fluctuation of the generator.

At the time of a sudden load change (eg load shedding), the speed detection signal S1 detected by the speed detector 1 is detected.
And the speed setting signal S2 set by the speed setting device 2,
The speed deviation signal S3 is output by the adder 3a. Then, in the adder 3e, the opening degree signal S7 output from the position detector 12 and the load setting signal S9 output from the load setting device 13 are added and calculated, and the output load deviation signal S16 is output.
The drooping load deviation signal S4 input to and output from the control circuit 14 is added to the adder 3b via the contact 15 in the open state to obtain the control deviation signal S4.
Ask for 3. Then, the control deviation signal S3 is processed into a signal according to each characteristic through the proportional unit 4 and the differentiator 5, and is output to the adder 3c. Further, the adder 3c sets the no-load opening bias α to the set time adder 3c by closing the contact 7b by the operation of the one-shot circuit 9 instead of the signal output from the integrator 6 during the normal operation. Output to.

Then, the opening command signal S6 output from the adder 3c and the opening signal S7 are added and operated to output an opening deviation signal S8 which is a signal output via the current / mechanical converter 10. The servo opening of 11 is controlled to control the rotational speed of the water turbine to the rated rotational speed.

[0010]

Since the conventional speed control device is configured as described above, a sudden load change (for example, load shedding etc.) occurs in a hydraulic power plant using a water turbine generator having a small moment of inertia. When occurs, the rotational speed of the water turbine accelerates and reaches the maximum rising rotational speed. Then, the speed control device controls the rotational speed of the water turbine to the rated rotational speed, but when the load fluctuates rapidly, the speed at which the maximum rising rotational speed falls to the rated rotational speed is faster than the speed at which the servo motor is operated. Therefore, the rated speed is greatly divided. Therefore, the one-shot circuit and the no-load opening bias α prevent the rated speed from being greatly divided, but the ON-time of the one-shot circuit (the time during which the no-load opening bias α is output) is different for each model. Since it is fixed for each (see FIG. 2B), the following problems occur.

Here, the time until the rotational speed of the hydraulic turbine returns to the rated rotational speed again after the rotational speed of the hydraulic turbine reaches the maximum rotational speed T1 and the one-shot circuit operates to output the no-load opening bias α. The time required is T2 (T2 depending on each model
The time is fixed. ).

For example, if the load is cut off when the output of the generator is large, the rotational speed of the water turbine will largely divide the rated rotational speed as shown by the broken line in FIG. 3 when T1> T2. ..

Further, as indicated by the broken line in FIG. 4 when T1 <T2, before the rotational speed of the water turbine returns to the rated rotational speed,
When the servo opening of the servo motor which was fully closed once is reopened, the rotational speed of the water turbine is secondarily increased.

Therefore, an object of the present invention is to perform speed control without unnecessary operation such as a breakdown of the rotational speed of the water turbine and a secondary increase of the rotational speed even when a sudden load change such as load shedding occurs. To obtain a speed control device.

[0015]

In order to achieve the above object, the present invention outputs a speed detector for detecting the rotational speed of a water turbine and outputting a speed signal, and a speed command signal for adjusting the rotational speed of the water turbine. Speed setter, a position detector that detects the servo opening of the servo motor and outputs an opening signal, a load setter that outputs a load command signal that adjusts the output of the water turbine, a speed signal and a speed command signal. From the opening deviation signal and the load command signal, and a second adder that outputs the load deviation signal from the opening signal and the load command signal, and the load deviation signal is processed according to the drooping characteristic. Droop rate setting device, a third adder that outputs a control deviation signal from a speed deviation signal and a drooping load deviation signal, and a proportional operation that inputs a control deviation signal and performs a proportional operation to output a proportional signal. Input the control deviation signal A differential calculator that performs a minute calculation and outputs a differential signal, an integral calculator that inputs a control deviation signal and performs an integral calculation and outputs an integrated signal, and a servo signal that inputs a proportional signal, a differential signal, and an integrated signal Degree of opening command signal is output, a fifth adder of outputting an opening deviation signal from the opening signal and the opening command signal, and an opening deviation signal of the servo motor servo open. Current / voltage converter that converts and outputs the signal that controls the degree, and a holding time calculator that calculates the ON signal of the setting signal output by the operating one-shot circuit according to the opening signal when the load fluctuates rapidly And a contact for inputting the setting signal instead of the integration signal to the fourth adder for the time calculated by the holding time calculator when the one-shot circuit is operated.

[0016]

With the above construction, the on-time of the signal output from the one-shot circuit becomes the maximum rising speed of the water turbine according to the opening signal of the servo opening of the servo motor during a sudden load change. After that, the control is performed so as to match the time until it returns to the rated speed again.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a configuration diagram of the speed control device according to the present embodiment. The speed detector 1 detects the rotation speed of a water turbine (not shown), and detects a speed detection signal S1 proportional to this rotation speed.
Is output. The speed setter 2 sets the rotational speed of the water turbine according to the operation in advance, and the speed setting signal S proportional to this rotational speed.
2 is output. The adder 3a performs addition calculation of the speed detection signal S1 and the speed setting signal S2 and outputs a speed deviation signal S3. The adder 3b performs an addition operation on the speed deviation signal S3 and the drooping load deviation signal S4 (which will be described later in detail) and outputs a control deviation signal S5. The proportionalizer 4 controls the control deviation signal S5.
Is processed according to the proportional characteristic and output to the adder 3c. The differentiator 5 processes the control deviation signal S5 according to the differential characteristic and outputs it to the adder 3c. The integrator 6 processes and outputs the control deviation signal S5 according to the integration characteristic via the contact 7a in the closed state during normal operation (operation with minute load fluctuations). Contact 8
Is closed when there is a sudden load change (for example, load shedding).

The one-shot circuit 9 changes the contact 7a from the closed state to the open state for a set time when the contact 8 is closed.
Further, the contact 7b in the open state is closed to output the preset no-load opening bias α to the adder 3c instead of the signal output from the integrator 6.

The holding time calculator 16 inputs the opening signal S7 output from the position detector 12, and according to this opening signal S7 (servo opening), the one-shot circuit 9 follows a preset function. Time T2 for outputting the no-load opening bias α to the adder 3c (that is, time T1 until the rotational speed of the water turbine reaches the maximum rising rotational speed when the load is cut off and returns to the rated rotational speed again)
Time equal to). Incidentally, FIG. 1B is a characteristic diagram showing the opening time signal S7 and the output time of the no-load opening bias α output from the one-shot circuit 9. Adder 3d
Outputs an opening deviation signal S8 by performing an addition operation on the opening command signal S6 and the opening signal S7 (which will be described in detail later) output from the adder 3c. The current / mechanical converter 10 converts the opening deviation signal S8 into a signal for controlling the servo opening of the servo motor 11. The position detector 12 detects the servo opening of the servo motor 11 and outputs an opening signal S7 corresponding to the servo opening.
Is output.

The adder 3e performs addition calculation of the load setting signal S9 and the opening signal S7 output from the load setter 13 in which the target load is set when the generators are operating in parallel with the system. The load deviation signal S10 is output.

The droop rate setter 14 processes the load deviation signal S10 according to a preset droop rate, and outputs a droop load deviation signal S4 via a contact 15 which is closed only when a sudden load change occurs. Next, the operation of the speed control device of this embodiment will be described.

During normal operation (operation with a slight load change), the speed detection signal S1 detected by the speed detector 1 and the speed setting signal S2 set by the speed setting device 2 are set by the adder 3a. The deviation signal S3 is output. Since the contact 15 is in the open state, only the speed deviation signal S3 is input to the adder 3b and the control deviation signal S5 is output. The control deviation signal S5 is supplied to the proportional unit 4, the differentiator 5, and the integrator 6. It is input, processed according to each characteristic, and output to the adder 3c. Then, the adder 3d outputs the open degree deviation signal S8 between the open degree command signal S6 output from the adder 3c and the open degree signal S7 output from the position detector 12, and the open degree deviation signal S8 is the current. / Servo motor 11 with mechanical converter 10
Is converted into a signal for controlling the servo opening degree. With the above operation, the rotational speed of the water turbine can be controlled to the rated rotational speed with respect to a minute load fluctuation of the generator.

During a sudden load change (for example, load shedding), the speed detection signal S1 detected by the speed detector 1 is detected.
And the speed setting signal S2 set by the speed setting device 2,
The speed deviation signal S3 is output by the adder 3a. Then, in the adder 3e, the opening degree signal S7 outputted from the position detector 12 and the load setting signal S9 outputted from the load setting device 13 are added and calculated, and the load deviation signal S10 outputted is outputted from the drooping rate setting device.
The drooping load deviation signal S4 input to and output from the control circuit 14 is added to the adder 3b via the contact 15 in the open state to obtain the control deviation signal S4.
Ask for 3. Then, the control deviation signal S3 is processed into a signal according to each characteristic through the proportional unit 4 and the differentiator 5, and is output to the adder 3c.

Further, in the adder 3c, instead of the signal output from the integrator 7 during the normal operation, the contact 7b is closed by the operation of the one-shot circuit 9 so that the no-load opening bias α is servo-controlled. Only the time calculated by the holding time calculator 16 is output according to the servo opening of the motor 11.

Then, in the adder 3c, the opening command signal S6 and the opening signal S7 output from the adder 3c are added and calculated, and the opening deviation signal S8 output is output via the current / mechanical converter 10. The signal controls the servo opening of the servo motor 11 to control the rotational speed of the water turbine to the rated rotational speed.

Since the present embodiment is configured as described above, in the case of light load interruption as shown by the solid lines in FIGS. 3 and 4, the rotation speed of the water turbine is small, so that the rotation speed returns to the rated speed. The time T1 is short and the servo motor 11
Since the servo opening of is also small, the operating time T2 of the one-shot circuit 9 calculated by the holding time calculator 16 is also shortened and T1 =
It becomes T2. On the other hand, in the case of full load cutoff, since the increase in the rotational speed of the water turbine is large, the time T1 for returning to the rated rotational speed is long, and the servo opening of the servo motor 11 at that time is also large. The operating time T2 of the one-shot circuit 9 also becomes longer, and T1 = T2.

[0027]

As described above, according to the present invention, in a power plant having a water turbine generator with a small moment of inertia, speed control for preventing unnecessary operation of the rotational speed of the water turbine when a sudden load change such as load shedding occurs. A speed control device for a water turbine is provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram and a characteristic diagram of a speed control device according to an embodiment.

FIG. 2 is a configuration diagram and a characteristic diagram of a conventional speed control device.

FIG. 3 is a time chart (T1> T2) of the speed control device at the time of load shedding according to this embodiment.

FIG. 4 is a time chart (T1 <T2) of the speed control device at the time of load shedding according to the present embodiment.

[Explanation of symbols]

 1 ... Speed detector 2 ... Speed setting device 3a, 3b, 3c, 3d, 3e ... Adder 4 ... Proportional device 5 ... Differentiator 6 ... Integrator 7a, 7b, 8, 15 ... Contact 9 ... One-shot circuit 10 ... Current / voltage converter 11 ... Servo motor 12 ... Position detector 13 ... Load setting device 14 ... Droop rate setting device 16 ... Holding time calculator

Claims (1)

[Claims] 1. A speed detector for detecting a rotation speed of a water turbine and outputting a speed signal, a speed setter for outputting a speed command signal for adjusting the rotation speed of the water turbine, and a servo opening degree of a servo motor for detecting the speed. A position detector that outputs an opening signal, a load setter that outputs a load command signal that adjusts the output of the water turbine, and a first adder that outputs a speed deviation signal from the speed signal and the speed command signal. A second adder that outputs a load deviation signal from the opening signal and the load command signal; a drooping rate setting device that processes the load deviation signal according to a drooping characteristic and outputs a drooping load deviation signal; A third that outputs a control deviation signal from the speed deviation signal and the drooping load deviation signal
Adder, a proportional calculator that inputs the control deviation signal to perform a proportional operation and outputs a proportional signal, a differential calculator that inputs the control deviation signal to perform a differential operation and output a differential signal, and the control deviation An integration calculator for inputting a signal, performing an integration operation and outputting an integration signal, and a fourth signal inputting the three signals of the proportional signal, the differentiation signal and the integration signal and outputting an opening command signal of the servo opening An adder, a fifth adder that outputs an opening deviation signal from the opening signal and the opening command signal, and the opening deviation signal is converted into a signal for controlling the servo opening of the servo motor. A current / voltage converter that outputs, a holding time calculator that calculates the on-time of a setting signal that is output by a one-shot circuit that operates when there is a sudden load change, and a holding-time calculator that operates when the one-shot circuit operates. The integrated signal It said setting signal the retention time calculator that is composed of a contact to enter only the calculated time to the fourth adder in governor control hydraulic turbine characterized in place