JPH05172034A - Governor control device - Google Patents

Abstract

PURPOSE:To enable power generating operation to be continued, even upon occurrence of a failure in a DC power supply. section and a speed detector by controlling the speed of a vane according to output voltage from an excitation power transformer and a vane speed signal detected from the frequency component of the output voltage. CONSTITUTION:The speed of a vane in a generator 1 is detected by a speed detector 7. On the other hand, voltage outputted from the generator 1 is converted to secondary voltage at a level exciting the field winding of an excitation control section with an excitation power transformer 3. Also, a power output section 5 normally takes in and outputs the DC voltage of a DC power supply section 4, while taking in the secondary voltage of the transformer 3 for conversion to DC voltage and subsequent output, upon occurrence of a failure. Furthermore, a signal conversion and output section 8a normally takes in the first speed signal from the speed detector 7, and takes in the voltage of the transformer 3 for conversion to the second speed signal, upon occurrence of a failure. Then, the speed of the vane is controlled by a control section 8b, according to the DC voltage of the power supply section 5 and the speed signal of the signal conversion and output section 8a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a governor control device for controlling the rotational speed of a water turbine of a hydraulic power plant to a specified rotational speed.

[0002]

2. Description of the Related Art Generally, a generator of a hydroelectric power plant is connected to an electric power system and operates in parallel with many other power plants.
Therefore, it is necessary to control each power plant to a target system frequency, and a governor control device is provided in the power plant. Hereinafter, a conventional governor control device will be described with reference to the drawings. FIG. 3 is a configuration diagram of a conventional governor control device.
The generator 1 is connected to the system via a generator main circuit 2 and a parallel circuit breaker (not shown).

The excitation power supply transformer 3 is connected to the generator main circuit 2 and outputs a voltage output from the generator 1 to a field winding of an excitation controller (not shown). Converted to voltage V2 and output. The DC power supply unit 4 is provided inside the power plant and outputs a DC voltage.

The power supply output unit 5 takes in the DC voltage output from the DC power supply unit 4 and also supplies the AC power supply unit 6 in the power plant.
The AC voltage output from is taken in and converted into a DC voltage of a predetermined level. Then, during normal operation, the DC voltage output from the DC power supply unit 4 is taken in, and when the DC power supply unit 4 fails, a DC voltage converted from the AC voltage output from the AC power supply unit 6 in the power plant is output. Speed detector 7
Detects the rotation speed of the generator 1 and outputs a speed detector signal S1. The governor control unit 8 has a signal conversion output unit 8a and a control unit 8b. The signal conversion output unit 8a converts the input speed detector signal S1 into a speed signal N1 and outputs it.

The control unit 8b adjusts the flow rate flowing into the water turbine in accordance with the speed signal N1 to adjust the control signal S2 for controlling the rotation speed of the water turbine to a specified rotation speed by adjusting a guide vane (not shown). Output to speed machine.

With the above-mentioned configuration, the DC power supply unit 4 which supplies the driving power to the governor control unit 8 during the operation of the generator 1 has a failure (short circuit or the like) and the DC power supply is lost. In this case, since the DC voltage converted from the normal AC voltage output from the AC power supply unit 6 in the power plant is supplied from the power supply output unit 5 to the governor control unit 8, the speed governor control unit 8 operates. Since it continues, the generator 1 also continues to operate.

[0007]

However, in the structure of the speed governor control device described above, the DC power supply unit fails, and the AC power supply in the power plant also fails, resulting in loss of input power to the speed governor control unit. In this case, the governor control unit does not operate, and the control signal output to the governor for adjusting the guide vanes is not output. Then, the speed governor also becomes inoperative, the guide vanes gradually close, and the generator enters the motoring state, making it impossible to continue the power generation operation.

When the speed detector fails, the speed governor control section outputs a signal to completely close the guide vanes to the speed governor because the speed governor control section does not receive the speed signal. The power generation operation of is changed from the load operation before the speed detector fails to the full load operation.

The present invention is a speed governor capable of continuing a power generation operation without causing load fluctuations of a generator when a DC power source is lost in a speed governor control device of a hydraulic power plant and a speed detector fails. It is to provide a control device.

[0010]

In order to achieve the above object, the present invention provides a speed governor control device for controlling the rotational speed of a water turbine of a generator of a hydroelectric power plant to a specified rotational speed. A speed detector that detects and outputs a speed signal, an excitation power supply transformer that converts the output voltage of the generator into a voltage of a level for exciting the field winding of the excitation control unit, and a predetermined generator installed in the power plant. The DC power supply unit that outputs the DC voltage of and the DC voltage output from the DC power supply unit during normal operation,
When the DC power supply unit fails, a power supply output unit that takes in the voltage output from the excitation power supply transformer,

During normal operation, the first speed signal output from the speed detector is taken in, the voltage output from the excitation power supply transformer is taken in when this speed detector fails, and it is converted into the second speed signal and output. A signal conversion output unit for

It has a control unit for taking in the voltage output from the power supply output unit and the speed signal output from the signal conversion output unit, and outputting a control signal for controlling the rotational speed of the water turbine to a specified rotational speed. To do.

[0013]

With the above configuration, the voltage output from the excitation power supply transformer is taken in even when the DC power supply unit fails and the DC power supply to the governor control unit is cut off.
Even if the speed detector fails and the speed signal to the governor control unit disappears, the generator operation continues because the speed signal of the turbine is detected from the frequency component of the voltage output from the excitation power transformer. Can be done.

[0014]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a governor control device according to the present embodiment. The generator 1 is connected to the system via a generator main circuit 2 and a parallel circuit breaker (not shown).

The excitation power supply transformer 3 is connected to the generator main circuit 2 and outputs a voltage output from the generator 1 to a field winding of an excitation controller (not shown). Converted to voltage V2 and output. The DC power supply unit 4 is provided inside the power plant and outputs a DC voltage.

The power supply unit output 5 takes in the DC voltage output from the DC power supply unit 4 and also takes in the secondary voltage output from the excitation power supply transformer 3 and converts it into a DC voltage of a set level. Then, during the normal operation, the DC voltage output from the DC power supply unit 4 is taken in, and when the DC power supply unit 4 fails, the DC voltage converted from the secondary voltage V2 output from the excitation power supply transformer 3 is output. The speed detector 7 detects the rotation speed of the generator 1 and outputs a speed detector signal S1. The governor control unit 8 has a signal conversion output unit 8a and a control unit 8b.

The signal conversion output unit 8a takes in the speed detector signal S1 output from the speed detector 7 during normal operation, converts it into a speed signal N1, and outputs the speed signal N1. When it is not obtained, the secondary voltage V2 output from the excitation power transformer 3 is taken in, and the speed signal N2 is output from the frequency component of this secondary voltage V2. The signal conversion output unit 8a will be described in detail with reference to the configuration diagram of FIG.

The signal converter converts the speed detector signal S1 which is a pulse output from the speed detector 7 for detecting the speed of the generator 1.
Converted to speed signal N1 at 80a. When the non-parallel condition 80b (the condition that the parallel circuit breaker (not shown) is open) is satisfied, the speed signal N1 is the speed signal N1 as it is.
Is output to the control unit 8b.

When the speed signal N1 satisfies the parallel condition 80c (the condition in which the parallel circuit breaker (not shown) is closed), the speed determination unit 80d determines that the speed signal N1 is near the rated speed. If it is determined that the speed signal N1 is output as it is to the control unit 8b as the speed signal N.

Further, 2 output from the excitation power transformer 3
The next voltage V2 is converted into a speed signal N2 by the signal converter 80e. The speed signal N2 satisfies the parallel condition 80c (the condition in which the parallel circuit breaker (not shown) is closed), and the speed detection abnormal condition 80f, that is, the speed determination unit 80d determines that the speed signal N1 is not near the rated speed. When the condition is satisfied, the speed signal N is output as it is to the control unit 8b.

The control unit 8b takes in the speed signal N obtained from the speed detector 7 output from the signal conversion output unit 8a during normal operation, and adjusts the flow rate flowing into the turbine in accordance with the speed signal N. A control signal S2 for controlling the rotational speed of the water turbine to a specified rotational speed is output to a speed governor (not shown) for adjusting a guide vane. When a failure occurs in the speed detector 7 and the speed signal N is not obtained from the speed detector 7, the speed signal N2 output from the signal conversion output unit 8a is detected, and the speed signal N2 is detected according to the speed signal N2. A control signal S2 for adjusting the flow rate flowing into the turbine to control the rotation speed of the turbine to a specified rotation speed is output to a speed governor (not shown) for adjusting a guide vane.

[0022]

As described above, according to the present invention, the secondary voltage of the excitation power source is used as the input power source of the governor control device,
Further, by obtaining the speed of the generator from the frequency of the secondary voltage, it is possible to obtain a governor control device capable of continuously performing reliable operation of the generator even when a failure occurs in the DC power supply unit and the speed detector. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram of a governor control device according to the present embodiment.

FIG. 2 is a configuration diagram of a signal conversion output unit of the speed governor control device of the present embodiment.

FIG. 3 is a configuration diagram of a conventional governor control device.

[Explanation of symbols]

1 ... Generator, 2 ... Generator main circuit, 3 ... Excitation power transformer,
4 ... DC power supply section, 5 ... Power supply output section, 6 ... AC power supply section, 7
... speed detector, 8 ... governor control unit, 8a ... signal conversion output unit, 8b ... control unit, 80a, 80c ... signal conversion unit, 80b ... non-parallel condition judging unit, 80c ... parallel condition judging unit, 80d ... Speed determination unit, S1 ... Speed detector signal, S2 ... Control signal, N1,
N2, N ... Speed signal, V2 ... Secondary voltage

Claims (1)

[Claims] 1. A speed governor control device for controlling the rotational speed of a water turbine of a generator of a hydraulic power plant to a prescribed rotational speed, a speed detector for detecting the rotational speed of the water turbine and outputting a speed signal, An excitation power supply transformer for converting the output voltage of the machine into a secondary voltage of a level for exciting the field winding of the excitation control unit, and a DC power supply unit provided in the power plant for outputting a predetermined DC voltage. During normal operation, the DC voltage output from the DC power supply unit is taken in and output, and when the DC power supply unit fails, the secondary voltage output from the excitation power supply transformer is taken in and converted into a predetermined DC voltage and output. The power supply output unit and the first speed signal output from the speed detector during normal operation are taken in, and the voltage output from the excitation power transformer is taken in when the speed detector fails, and the second speed signal is taken in. And output No. conversion output unit, a control signal that takes in the DC voltage output from the power supply output unit and the speed signal output from the speed signal output unit, and controls the rotation speed of the water turbine to a specified rotation speed according to the speed signal. A speed governor control device, comprising: