JPS58144671A - Electric power fluctuation restraining device for water turbine generator - Google Patents

Abstract

PURPOSE:To permit the restraining of the electric power fluctuation with high-speed response by a method wherein the electric power fluctuation of the water turbine generator is detected as a change of hydraulic pressure in the draft tube of the water turbine and a guide vane is controlled directly to a direction to eliminate the detected change. CONSTITUTION:In the titled device, the information of the electric power, fluctuation, detected by a current transformer 5 and a voltage transformer 6, is inputted into an electric power system stabilizing unit 8 as an input signal. Said unit 8 controls the amount of magnetic excitation in a magnetic excitation unit 7 by inputting the information of the electric power fluctuation into an automatic voltage regulating unit 9 to restrain the electric power fluctuation by increasing braking torque. In the above-described device, a torque transmitted to the water turbine 2 is fluctuated to detect flow fluctuation in the draft tube 4 of the water turbine, which is the cause to generate the electric power fluctuation, by a hydraulic pressure detecting unit 10. The detecting signal is changed into a control signal to eliminate the fluctuation of the flow of water by a water flow pulsation operating unit 11 and the opening degree of the guide vane 3 is adjusted by an electric governor 12 based on the control signal thereby restraining the electric power fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for suppressing power fluctuations in a water turbine generator, particularly by controlling the opening and closing of guide vanes.

As a conventional power oscillation suppressing device, there is one shown in Figure O1. (1) is a water turbine generator, (2) is a water turbine, (31 guide vanes, f4) is a water turbine suction pipe, (5) is a water turbine generator (current transformer that detects the output current of 11, (6) is Voltage transformation to detect the output voltage of the water turbine generator +11, (7
) is an exciter that applies field current to the water turbine generator fi+, (8
) is a device ( ) that detects the magnitude and phase of power fluctuations using signals from the current transformer (5) and voltage transformer (6).
) is an automatic voltage regulator that provides a control signal to the

Next, the operation of the conventional power oscillation suppressing device when the water turbine generator +11 is operated in parallel with the power system will be described.

If power fluctuations occur due to speed changes or load changes of other generators connected in parallel to the power grid, the current transformer (
6) and the information on the power fluctuation detected at the voltage transformer (6) is given to the power system stabilizing device (8) as a occupancy signal. The power system stabilizing device (8) adds this power fluctuation information to the self-help voltage regulator f91K.
In the excitation device (7)), the amount of magnetism is controlled;
) to suppress power fluctuations.

Power fluctuations that occur when a water turbine generator is operated in parallel with the power system include those caused by the above-mentioned 1. Some of these problems are caused by the pulsation of the water flowing through the turbine's suction pipe. Power fluctuations caused by water flow pulsations in the water turbine suction pipe occur in the following situations. In general, water turbine power generation
When the water turbines are operated in parallel near the water turbine suction pipe (4), air bubbles are generated and disappeared at specific intervals in the water flow flowing through the water turbine suction pipe (4), causing pulsation in the water flow. Due to the pulsation of this water flow, the torque transmitted to the water turbine fil K fluctuates, causing power fluctuations in the output of the water turbine generator 1).

In the conventional power oscillation suppressing device, after the fluctuation in the torque of the water turbine (2) appears as a fluctuation in the output of the water turbine generator Il+, this is detected as an auxiliary signal for suppressing the power oscillation. In addition, the excitation device of the water turbine generator +11 has a large time constant, which causes a time delay in power fluctuation suppression control, and the water turbine suction pipe (4 ) could not suppress the power oscillation caused by the water king's gland movement.

This invention was made in view of the above-mentioned drawbacks, and it detects the change in water pressure occurring in the water turbine suction pipe (4) and moves the guide vane (3) in the direction of canceling the detected change.
) The object of the present invention is to provide a power supply that can suppress power fluctuations in a high-speed response by controlling the power supply voltage.

An embodiment of the present invention will be described below with reference to the drawings. Fang 8
In the figure, (1) to (9) show parts that are the same as or equivalent to the conventional one shown in Fig. 1.
0 odor indicates an electric governor.

Next, the operation will be explained. Water turbine suction pipe 1 that fluctuates the torque transmitted to the water turbine (2) and causes power fluctuations
The water flow pulsation in the water wheel suction pipe (4) is detected by the water turbine suction pipe internal water pressure detection device - as a change in water pressure inside the water turbine suction pipe (4).

This detection signal is used as input No. 1 and is converted into a control signal for canceling the fluctuation of the water flow by a water flow pulsation calculation device (!l) in the water turbine suction pipe. Based on this signal, the air speed governor (+2) adjusts the opening of the guide vane 1310 to suppress power fluctuations.

As described above, according to the present invention, power fluctuation is detected as a change in water pressure in the water suction pipe (4) and the guide vane is directly controlled, so power fluctuation is suppressed by high-speed response. This makes it possible to maintain the stability of the power system.

[Brief explanation of drawings]

Fig. 1 is a control diagram of a conventional electric power oscillation suppressing device, and Fig. 2 is a control diagram showing an embodiment of the present invention, in which 11) is a water turbine generator, (2) is a water turbine, and (3) is a control diagram showing an embodiment of the present invention. Guide vane, (4
) is the water turbine suction pipe, (1α is the water pressure detection device in the water turbine suction pipe,
(■) is a water flow pulsation calculation device in the water turbine suction pipe, and an IJ2 electric speed governor. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Ia Kuzuno - Figure 1 Figure 2

Claims (1)

[Claims] It has a device that detects the water pressure in the water turbine suction pipe of the water turbine generator and a device that calculates the water pressure suction in the water I suction pipe, and uses the output signal of this device to move the guide vanes of the water turbine to f (1 m). Features: A power oscillation suppression device for water turbine generators.