JP2537671Y2 - Control device for movable wing turbine - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a control device for a movable wing turbine, and in particular, a movable wing capable of suppressing fluctuations in generator output and an increase in amplitude during racing. The present invention relates to a control device for a water turbine.

(Prior Art) The load on the generator of a hydroelectric power station is not constant but changes from time to time. If the load is changed while the inlet opening of the turbine is kept constant, the number of rotations of the turbine changes because the amount of inflow water is excessive or insufficient. In this case, if the load decreases, the rotation speed increases,
If the load increases, the speed decreases. If there is such a fluctuation in the number of revolutions, the generator directly connected to the turbine
This causes frequency irregularities. Therefore, the turbine must always maintain the specified rotation speed regardless of the load.
Even if the load changes in this way, in order to maintain the specified number of revolutions, the opening degree of the inflow port may be adjusted in response to the increase or decrease in the load to increase or decrease the amount of water flowing into the water turbine. There is a governing device as a device that regulates the amount of water and keeps the rotation speed constant.

By the way, despite the constant load of the turbine, the speed governor opens and closes the water port, or alternately repeats the opening and closing operation of the water port and the rise and fall of the rotation speed. Yes, this is called racing. The cause is a failure of the restoration mechanism, a failure of the hydraulic mechanical system, or the failure of the electric circuit. When this racing occurs, the vibration of the generator is induced or the output of the generator fluctuates.

(Problems to be Solved by the Invention) By the way, movable wing turbines such as Kaplan turbines and tubular turbines can be operated at the highest efficiency regardless of the guide vane opening so that the runner vanes correspond to the guide vane opening. Is set in advance. This example will be described with reference to FIG. In FIG. 4, the horizontal axis represents the guide vane opening in percentage, and the vertical axis represents the runner vane opening in percentage. From the curve representing the runner vane opening with respect to the guide vane opening using the head as a parameter, the runner vane opening b that achieves the highest efficiency when the guide vane opening a is obtained. Therefore, the control device detects the guide vane opening, converts it to the target opening of the runner vane, and controls the opening and closing of the runner vane by operating the runner vane operating pressure distribution valve. However, there is a delay in the control of the runner vanes with respect to the guide vanes, and when racing occurs, there is a possibility that the amplitude of the vibration of the generator or the output fluctuation is amplified.

The present invention has been made in view of the above-described problems, and has as its object to provide a control device of a movable wing turbine that prevents fluctuation of a generator output and expansion of amplitude due to racing.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the control device for the movable wing turbine of the present invention uses the movable wing turbine to generate power from the generator of the power generator at regular intervals. And the difference between adjacent points in the generator output is taken three or more times in succession, provided that the difference is "positive, negative, positive" or "negative, positive, negative" Racing detection means for judging racing and outputting a racing signal; runner vane control means for controlling the runner vane to a target opening based on the guide vane opening of the movable wing turbine; and opening of the runner vane provided in the runner vane control means. Opening degree fixing means for fixing the degree to a predetermined value or a runner vane opening degree at the time of racing, and when racing is detected by the racing detecting means, the generator is operated in parallel with the power system. It is those provided with a switching means for switching from the target opening control of the given switching command runner vanes to the fixed opening by the opening the fixing means to the runner vane control unit on condition.

(Operation) When the racing is detected by the racing detection circuit according to the above-described configuration, the switching means uses a logical product condition of the racing detection signal and a parallel signal indicating that the generator is operating in parallel with the power system. Since the mode is switched to the opening degree fixing means provided in the runner vane control circuit, the runner vane control circuit controls the runner vane driving device so that the opening degree of the runner vane becomes the fixed opening degree. By fixing the opening of the runner vane, the expansion of the amplitude due to the fluctuation of the generator output due to racing is suppressed, and the adverse effect on the power system and equipment is reduced.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. The runner vane control device according to the first embodiment switches a function generator 1 that converts a guide vane opening into a runner vane opening with high efficiency, and switches between an output of the function generator 1 and a predetermined runner vane opening setting. Changeover switch 2
An adder / subtractor 3 for subtracting the feedback value of the vane opening of the runner vane 5 from the output of the changeover switch 2;
A racing detection circuit 6 for inputting a generator output to detect racing, and an AND circuit 7 for performing an AND operation of an output of the racing detection circuit 6 and a parallel signal 17 indicating that the generator is operating in parallel with the power system. And a relay 8 for switching the changeover switch 2 by the output of the AND circuit 7.

The operation of the runner vane control device configured as described above will be described.

During normal operation, the guide vane opening 10 is converted into the runner vane target opening 11 by the function generator 1, the feedback value of the runner vane opening 14 from the runner vane 5 is subtracted by the adder / subtractor 3 and input to the runner vane driving device 4. The runner vane 5 is opened and closed.

When a racing occurs, the racing detection circuit 6 inputs the generator output 15 and outputs a racing signal 16, and inputs the racing signal 16 and the parallel signal 17 to the AND circuit 7 to output the relay drive signal 18. The relay 8 switches the changeover switch 2 by the relay drive signal 18 to forcibly bring the target runner vane opening 11 to an arbitrary opening set value 12 (for example, 50% opening), and fixes the opening set value 12. I do. This suppresses an increase in amplitude due to fluctuations in the generator output due to racing, and reduces adverse effects on the power system and equipment.

 Next, a method of detecting racing will be described with reference to FIG.

FIG. 2 shows a change in the output (MW) of the generator with respect to time T. The difference (W _n −W _n−1 ) between adjacent points in the generator output is taken at regular time intervals t. If this difference is positive, the output is set to “1” in the increasing direction. The memory is sequentially stored as “0” as it is in the decreasing direction, and a certain time tc
If there is a pattern of (0-1-0) or (1-0-1), it is determined to be racing and a racing signal is output.

Since the increase / decrease of the generator output corresponds to the opening / closing of the guide vane, the racing phenomenon can be detected by using the opening / closing operation of the guide vane instead of the generator output.

 Next, a second embodiment will be described with reference to FIG.

FIG. 3 is a block diagram showing the configuration of the second embodiment.
The difference from the first embodiment is that the runner vane opening set value 12 is changed to the runner vane opening 14. When the racing is detected by this change, the opening degree of the runner vane at the time of the detection is fixed, and the same effect as in the first embodiment can be obtained.

[Effects of the Invention] As is clear from the above description, the present invention fixes the runner vane opening to a predetermined value or the opening at the time of racing detection when racing is detected, thereby causing fluctuation of generator output and expansion of amplitude. Can be prevented, and adverse effects on the power system and equipment can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention,
FIG. 2 is a diagram for explaining a racing detection method, FIG. 3 is a block diagram showing a configuration of a second embodiment, and FIG. 4 is a diagram showing a relationship between guide vane opening and runner vane opening. DESCRIPTION OF SYMBOLS 1 ... Function generator, 2 ... Changeover switch, 3 ... Adder / subtractor, 4 ... Runner vane drive device, 5 ... Runner vane, 6 ... Racing detection circuit, 7 ... AND circuit, 8 ...
…relay.

Claims (1)

(57) [Scope of request for utility model registration] 1. A generator output of a power generator for generating electricity using a movable wing turbine is input at regular intervals, and a difference between adjacent points of the generator output is continuously taken three times or more. positive and negative,
`` Positive '' or `` negative, positive, negative '' on the condition that it is determined to be racing and outputs a racing signal, and a target opening of the runner vane based on the guide vane opening of the movable wing turbine. Runner vane control means, an opening degree fixing means provided in the runner vane control means for fixing the opening degree of the runner vane to a predetermined value or a runner vane opening degree at the time of racing, and racing detected by the racing detection means. Then, under the condition that the generator is operated in parallel with the electric power system, a switching command is given to the runner vane control means to switch from the target opening control of the runner vane to the fixed opening by the opening fixing means. And a control unit for a movable wing turbine.