JPS6214714B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric speed governor that controls the opening degree of guide vanes to keep the output and frequency of a water turbine generator stable against system frequency fluctuations and load fluctuations. It is.

Generally, in a water turbine generator, when the load is constant, the water turbine generator is operated at a specified rotation speed, but when the load changes, an imbalance with the output occurs and the rotation speed changes. Therefore, in the electric speed governor,
It detects the change in the rotational speed and adjusts the opening degree of the guide vane to maintain a specified rotational speed.

The basic circuit configuration of this type of electric speed governor is shown in FIG. That is, in FIG. 1, reference numeral 10 indicates a frequency detector;
This frequency detector 10 detects frequency fluctuations as changes in the rotational speed of the water turbine generator. The output signal of the frequency detector 10 is compared with the frequency setting signal from the frequency setter 12 in the deviation detector 14 to determine the deviation, and this deviation output is supplied to the frequency adjuster 16. In the frequency adjuster 16, the control elements are proportional (P), integral (I) and differential (D).
The guide vane opening control signal is obtained by changing one or more of the constants of the control elements P-ID according to the generator output state, the guide vane opening, etc. In this way, the frequency adjuster 1
The control signal obtained in step 6 is compared with the feedback signal indicating the current opening degree of the guide vane in the opening degree deviation adjuster 18 to determine the deviation, and the obtained control signal is sent to the opening degree adjuster 20. It is configured to be supplied to the servo motor drive circuit 22 to control the opening degree of the guide vane.

However, in the control system of the electric speed governor described above, the control element P in the frequency adjuster 16
When changing the -ID constant, there is a problem in that the difference in the resulting control signal output value causes unnecessary fluctuations in the guide vane opening, the output of the water turbine generator, or the rotational speed (frequency).

Therefore, the inventors of the present invention have conducted various studies in order to overcome all the problems of the conventional electric speed governor mentioned above.
In addition, a switching permission circuit is provided which inputs the output signals of these calculation units and a command signal from an external condition switching command circuit. The magnitude of the output value of each arithmetic unit is monitored, and when these output values are equal, a switching contact is operated to change the constant of the control element using the output signal of one of the arithmetic units. It has been found that this makes it possible to prevent the reverse control characteristic from being given to the control signal for adjusting the opening degree of the guide vane, and that the above-mentioned problems can be solved at once.

Therefore, an object of the present invention is to provide smooth and stable control without adjusting the guide vane opening or causing unnecessary fluctuations in the generator output when the constants of the control elements are changed due to fluctuations in the rotational speed of the water turbine generator. It is to provide an electric speed governor of a water turbine generator that can be achieved.

In order to achieve the above object, the present invention detects fluctuations in the rotation speed of the water turbine generator, inputs this detection signal to a frequency adjuster, and adjusts the constant of the control element to the output state of the water turbine generator and the guide vane. In an electric speed governor configured to switch according to the opening degree of A switching permission circuit is provided for monitoring together with the switching command signal, and a switching contact is provided in the switching permission circuit that operates when the value or polarity of the output signal from the arithmetic unit becomes equal, and the operation of the switching contact changes the constant of the control element. It is characterized by being configured to perform switching changes.

In the above-mentioned electric speed governor, the two types of computing units having different values of gain and time constant or both are composed of elastic restoring computing units, and the magnitude of the output value of these computing units is controlled by a switching permission circuit. Can be configured to monitor. In this case, it is preferable to input a frequency adjustment signal to the switching permission circuit and monitor the value of this frequency adjustment signal and the magnitude or polarity of the output value of each arithmetic unit.

As an alternative, two types of computing units with different values of gain and time constant or both may be two types in which a proportional computing unit, an integral computing unit, and a differential computing unit are connected in parallel.
It is also possible to configure the system to include a set of arithmetic units, and to monitor the magnitude or polarity of the summed output values of these arithmetic units and the output value from the guide vane opening detector using a switching permission circuit.

Next, embodiments of an electric speed governor for a water turbine generator according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 shows a system diagram of a control system showing an embodiment of the electric speed governor according to the present invention. The system diagram shown in FIG. 2 corresponds to the frequency adjuster 16 of the circuit shown in FIG. That is, in the embodiment shown in FIG. 2, the frequency deviation signal obtained by the deviation detector 14 is added to the signal obtained via the differential calculator 24 by the adder 26, and then this added signal will be described later. The adder 30 is configured to add the output signal to a signal obtained via the stiffness restoration calculator 28. The output signal of the adder 30 is obtained by adding the output signals of the elastic restoring calculators 32 and 34, which are configured to have different values of gain and time constant, or both. Arithmetic unit (or auxiliary servo motor) 40
An output signal to the servo motor drive circuit 22 (see FIG. 1) is generated through the servo motor drive circuit 22 (see FIG. 1). However, in this embodiment, the elastic restoring calculator 3
2 and 34 to the adder 36, the output signals from the integral calculator 40 are input to the elastic restoring calculators 32 and 34, and the output signals from the integral calculator 40 are input to the elastic restoring calculators 32 and 34.
The calculation output signals No. 2 and 34 are input to the switching permission circuit 42, and the command signal from the external condition switching command circuit 44 is input to the switching permission circuit 42, and when the command signal is input, the calculation output signals are compared. When the values are equal, the switching contact 46 is operated to supply the adder 36 with the output signal of one of the arithmetic units 32 and 34, and the amplifier 38 and the integral arithmetic unit 40
The configuration is configured so that reverse direction control is not given to the

In this way, the circuit of this embodiment is provided with the switching permission circuit 42, which monitors the output signals of the elastic restoring calculators 32 and 34, which have different values of gain and time constant, or both. It is possible to prevent reverse control characteristics from occurring in the control signals supplied to the amplifier 38 and the integral calculator 40 at the timing when the values of the output signals of can be prevented.

FIG. 3 shows another embodiment of the electric speed governor according to the present invention, in which the circuit shown in FIG. 2 is slightly modified to supply the output signal of the adder 30 to the switching permission circuit 42. It is something. That is, in this embodiment, (output value of adder 30 - output value of elastic restoring calculator 32) and (output value of adder 30 - output value of elastic restoring calculator 34) are switched by the switching permission circuit 42. They can be monitored in the same manner as in the previous embodiment, and if the values are equal or of the same polarity, the switching contact 46 is activated and operated in the same manner as in the previous embodiment.

FIG. 4 shows yet another embodiment of the electric speed governor according to the present invention. In this embodiment, a parallel P-I-D system is adopted, and a set of computing units including a proportional computing unit 48, an integral computing unit 50, and a differential computing unit 52 are connected in parallel; and another set of computing units in which a proportional computing unit 54, an integral computing unit 56, and a differential computing unit 58 are connected in parallel, each having a different value of gain and time constant, respectively. ，
The output signals are added by adders 60 and 62, respectively, and the resulting signal is monitored by a switching permission circuit 42. In this embodiment, a guide vane opening degree detector 64 is provided, and the output signal from this detector 64 is sent to the rigidity restoration calculator 28.
The signal is supplied to the adder 26 via the adder 26, where it is added to the detection signal from the deviation detector 14. Further, the output signal of the detector 64 is supplied to the switching permission circuit 42, and in this switching permission circuit 42, (output value of adder 60 - output value of detector 64) and (output value of adder 62 - detection The output value of the adder 64) is monitored, and when the values are equal or have the same polarity, the switching contact 46 is operated and the output value of the adder 64 is monitored.
The output signal of one of the adders 60 and 62 is supplied to the adder 6 to directly control the servo motor drive circuit 22 via the amplifier 38. In this case, the output signal of the detector 64 is also supplied to the adder 66. In this embodiment as well, the same effects as in the embodiment shown in FIG. 2 can be obtained.

As is clear from the embodiments described above, according to the present invention, when changing the constant of the control element, there is no shock such as fluctuation in the opening degree adjustment of the guide vane or in the generator output or rotation speed.
Smooth operation control of the water turbine generator can be achieved. That is, the response characteristics of the water turbine generator according to the present invention when the load fluctuates are as shown by the solid line in FIG. Therefore, it can be seen that this response characteristic draws an extremely smooth curve compared to the characteristic of the conventional system (indicated by a broken line).

The device of the present invention can achieve stable speed control of a water turbine generator with a relatively simple circuit configuration, and can improve the performance of this type of electric speed governor.

Although the preferred embodiments of the present invention have been described above, the present invention can be applied not only to electric speed governors, but also to various analog and digital calculation devices that change control constants according to the state of the controlled object. Of course, various other design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram showing the basic configuration of an electric speed governor for a water turbine generator, Fig. 2 is a main circuit diagram showing an embodiment of the electric speed governor according to the present invention, and Fig. 3 is a block circuit diagram showing the basic configuration of an electric speed governor according to the present invention. FIG. 4 is a circuit diagram of a main part showing another embodiment of the electric speed governor of the present invention. FIG. 5 is a circuit diagram of a main part showing still another embodiment of the electric speed governor of the present invention. FIG. 3 is a response characteristic curve diagram for load fluctuations. 10... Frequency detector, 12... Frequency setter, 14... Deviation detector, 16... Frequency adjuster, 18... Opening degree deviation adjuster, 20... Opening degree adjuster, 22... Servo motor Drive circuit, 24... Differential calculator, 26, 30, 36, 60, 62, 66
... Adder, 28 ... Rigidity restoration calculator, 32,3
4...Elastic restoring calculator, 38...Amplifier, 40...
...Integral calculator, 42...Switching permission circuit, 44...
External condition switching command circuit, 46...Switching contact, 4
8, 54... Proportional calculator, 50, 56... Integral calculator, 52, 58... Differential calculator, 64... Guide vane opening degree detector.

Claims (1)

[Claims] 1. Detect fluctuations in the rotational speed of the water turbine generator, input this detection signal to a frequency adjuster, and adjust the constant of the control element according to the output state of the water turbine generator, the opening degree of the guide vane, etc. In an electric speed governor configured to perform switching changes based on the speed control, two types of computing units with different values of gain and time constant or both are provided, and the output signals of these computing units are monitored together with an external condition switching command signal. A switching permission circuit is provided, and the switching permission circuit is further provided with a switching contact that operates when the values or polarities of the output signals from the arithmetic unit become equal, and the constant of the control element is switched or changed by the operation of the switching contact. An electric speed governor for a water turbine generator, characterized by comprising: 2. In the electric speed governor for a water turbine generator as set forth in claim 1, the two types of computing units having different values for either or both of the gain and the time constant are constituted by elastic restoring computing units, and these computing units An electric speed governor for a water turbine generator configured to monitor the magnitude of the output value of the generator using a switching permission circuit. 3. In the electric speed governor for a water turbine generator according to claim 2, a frequency adjustment signal is input to the switching permission circuit, and the value of this frequency adjustment signal and the magnitude or polarity of the output value of each arithmetic unit are determined. An electric speed governor for a water turbine generator configured to monitor. 4. In the electric speed governor for a water turbine generator as set forth in claim 1, the two types of computing units having different values of gain and time constant or both are a proportional computing unit, an integral computing unit, and a differential computing unit. It consists of two groups of computing units connected in parallel with the unit, and the switching permission circuit monitors the summed output values of these computing units and the magnitude or polarity of the output value from the guide vane opening detector. An electric speed governor for a water turbine generator configured as follows.