JPH0647670U - Governor control device - Google Patents

Abstract

(57) [Summary] [Purpose] When the pilot valve is adsorbed, it is detected and the value of the AC voltage applied to the converter coil is increased to eliminate the effect of adsorption of the pilot valve.
As a result, the occurrence of racing is prevented in advance without requiring manpower. [Structure] When adsorption occurs in the pilot valve 8 and the value of the converter coil drive signal output from the operational amplifier circuit 5 becomes large, the voltage monitor circuit 6 detects this and outputs from the small vibration voltage setting circuit 2. In place of the generated fine vibration voltage, the fine vibration voltage output from the large fine vibration voltage setting circuit 3 is switched to increase the value of the AC voltage to be superimposed on the converter coil drive voltage, thereby vibrating the pilot valve 8 greatly. .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a governor control device that uses a pilot valve to control the rotation speed of a water turbine installed in a hydroelectric power plant.

[0002]

[Prior art]

 In a hydroelectric power plant, a speed governor captures the rotation speed of the generator, the feedback signal of the opening of the vane, etc., and drives the converter coil so that the power generation frequency of the generator is at the set frequency. The valve is controlled and the main valve is operated to adjust the opening of the vane.

FIG. 2 is a block diagram showing an example of a main part of such a governor control device.

The governor control device shown in this figure includes a feedback calculation circuit 101 that takes in a rotational speed of a generator, a vane opening feedback signal, and the like to generate a vane opening command signal, and a pilot operation circuit. A slight vibration voltage setting circuit 102 for setting a slight vibration voltage for constantly stimulating the valve 105, an opening command signal output from the feedback calculation circuit 101, and a slight vibration voltage signal output from the slight vibration voltage setting circuit 102. , An operational amplifier circuit 103 for generating a converter coil drive signal by performing arithmetic processing and amplification processing, a converter coil 104 driven by the converter coil drive signal output from the operational amplifier circuit 103, and the converter coil 104. And a pilot valve 105 driven by.

Then, the opening degree command signal is calculated by the feedback calculation circuit 101, and at the same time, the opening degree command signal and the slight vibration voltage signal output from the slight vibration voltage setting circuit 102 are fetched by the operational amplification circuit 103. To generate a converter coil drive signal, which is supplied to the converter coil 104 to drive the converter coil 104.

As a result, the pilot valve 105 is controlled, and the main valve (not shown) is controlled by the hydraulic pressure controlled by the pilot valve 105 to adjust the opening of the vane.

[0007]

[Problems to be solved by the device]

 However, the above-described conventional governor control device has the following problems.

That is, in order to prevent racing due to adsorption of the pilot valve 105, 0.3 to 0 is applied to the converter coil 104 directly connected to the pilot valve 105 based on the fine vibration voltage signal output from the fine vibration voltage setting circuit 102. An AC voltage of 0.7 V is applied to constantly vibrate the pilot valve 105, thereby eliminating the influence of the adsorption of the pilot valve 105.

However, even if such control is performed, if the friction increases due to the suction of the pilot valve 105, the control operation is performed unless the pilot valve 105 stops and the control deviation voltage does not increase. There will be no racing and racing will occur.

Therefore, the conventional speed governor control device has a problem that when such a situation occurs, it is necessary to manually handle the situation manually.

In view of the above circumstances, the present invention can detect the adsorption of the pilot valve and increase the value of the AC voltage applied to the converter coil to eliminate the influence of the adsorption of the pilot valve. It is an object of the present invention to provide a governor control device capable of preventing the occurrence of racing without requiring human labor.

[0012]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention generates a converter coil drive signal in which an AC voltage is superimposed on a feedback signal to control a pilot valve, thereby controlling the vane opening of the turbine to rotate the turbine. In the governor control device that adjusts the speed, when the value of the converter coil drive signal is equal to or greater than the preset value, a detection unit that detects this, and when this detection unit performs a detection operation, And an AC voltage value switching unit for increasing the value of the AC voltage superimposed on the converter coil drive signal.

[0013]

[Action]

 In the above configuration, when the value of the converter coil drive signal applied to the converter coil becomes equal to or greater than the preset value, when the detection unit detects it, the AC voltage value switching unit causes the converter coil The value of the AC voltage superimposed on the drive signal is increased to prevent the occurrence of racing due to the adsorption of the pilot valve.

[0014]

【Example】

 FIG. 1 is a block diagram showing an embodiment of a main part of a governor control device according to the present invention.

The speed governor control device shown in this figure includes a feedback calculation circuit 1, a small / fine vibration voltage setting circuit 2, a large / fine vibration voltage setting circuit 3, a changeover switch 4, an operational amplifier circuit 5, and a voltage. It is equipped with a monitoring circuit 6, a converter coil 7, and a pilot valve 8. It generates an opening command signal based on a generator speed signal, a turbine valve opening detection signal, etc. The converter coil 7 is driven by superimposing a small AC voltage on the command signal to operate the pilot valve 8, and the main valve (not shown) is driven by the hydraulic pressure controlled by the pilot valve 8. Adjust the vane opening of the turbine. When adsorption occurs on the pilot valve 8, it is detected and the value of the AC voltage superimposed on the converter coil drive signal is increased to remove the effect of adsorption on the pilot valve 8 without manpower required. Prevents racing from occurring.

The feedback calculation circuit 1 takes in a valve opening detection signal indicating a rotational speed of the generator or a vane opening of a water turbine that rotates the generator, and calculates the opening command signal. It is generated and supplied to the operational amplifier circuit 5.

Further, the small vibration voltage setting circuit 2 generates a minute vibration voltage signal necessary for giving a small stimulus to the pilot valve 8, and supplies this to the changeover switch 4.

Further, the large vibration voltage setting circuit 3 generates a minute vibration voltage signal required to give a large stimulus when adsorption occurs on the pilot valve 8, and supplies this to the changeover switch 4.

The change-over switch 4 outputs the minute vibration voltage signal output from the small minute vibration voltage setting circuit 2 from the large minute vibration voltage setting circuit 3 based on the switching signal output from the voltage monitoring circuit 6. It is switched to the output micro-vibration voltage signal and supplied to the operational amplifier circuit 5.

The operational amplifier circuit 5 takes in the opening command signal output from the feedback arithmetic circuit 1 and the micro-vibration voltage signal output from the changeover switch 4, and performs arithmetic processing and amplification processing. A converter coil drive signal is generated by superimposing an AC voltage corresponding to the minute vibration voltage signal on the opening command signal, and the converter coil drive signal is supplied to the voltage monitoring circuit 6 and the converter coil 7.

The voltage monitoring circuit 6 monitors the value of the converter coil drive signal output from the operational amplifier circuit 5, and when the value is smaller than a preset value, it does not generate an output and the small vibration is generated. The output of the voltage setting circuit 2 is supplied to the operational amplifier circuit 5 via the changeover switch 4. Then, when the value of the converter coil drive signal becomes larger than a preset value, it is determined that adsorption has occurred in the pilot valve 8, a switching signal is generated, and the changeover switch 4 is changed over. The output of the slight vibration voltage setting circuit 3 is supplied to the operational amplifier circuit 5.

Further, the converter coil 7 drives the pilot valve 8 by generating a driving force according to the converter coil drive signal output from the operational amplifier circuit 5.

The pilot valve 8 is controlled by the converter coil 7 to form a control hydraulic passage in either a neutral position or a closing direction or an opening direction, and drives the main valve to control the opening of the vane of the water turbine. adjust.

As described above, in this embodiment, when adsorption occurs on the pilot valve 8 and the value of the converter coil drive signal output from the operational amplifier circuit 5 increases, the voltage monitor circuit 6 detects this. Instead of the fine vibration voltage output from the small fine vibration voltage setting circuit 2, the fine vibration voltage output from the large fine vibration voltage setting circuit 3 is switched to increase the value of the AC voltage to be superimposed on the converter coil drive voltage. As a result, the pilot valve 8 is made to vibrate greatly, so that when the pilot valve 8 is adsorbed, the vibration of the converter coil 7 can be increased to eliminate the influence of the adsorption of the pilot valve 8. It is possible to prevent the occurrence of racing without requiring.

[0025]

[Effect of device]

 As described above, according to the present invention, when the pilot valve is adsorbed, it can be detected and the value of the AC voltage applied to the converter coil can be increased to eliminate the influence of the adsorption of the pilot valve. By doing so, it is possible to prevent the occurrence of racing without requiring manpower.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a main part of a governor control device according to the present invention.

FIG. 2 is a block diagram showing an example of a main part of a conventionally known governor control device.

[Explanation of symbols]

 1 Feedback calculation circuit 2 Small vibration voltage setting circuit 3 Large vibration voltage setting circuit 4 Changeover switch (AC voltage value changeover section) 5 Operational amplification circuit 6 Voltage monitoring circuit (detection section) 7 Converter coil 8 Pilot valve

Claims (1)

[Scope of utility model registration request] 1. A governor controller for generating a converter coil drive signal in which an AC voltage is superimposed on a feedback signal to control a pilot valve, thereby controlling a vane opening of a water turbine and adjusting a rotation speed of the water turbine. When the value of the converter coil drive signal is equal to or greater than a preset set value, a detection unit that detects this, and when this detection unit performs a detection operation, an AC voltage that is superimposed on the converter coil drive signal A governor control device comprising: an AC voltage value switching unit that increases the value.