Unsteady flow control system for hydropower station downstream model test

Abstract

The invention discloses an unsteady flow control system for a hydropower station downstream model test. The unsteady flow control system compiles a flow change process of unsteady flow into a data file corresponding to time flow, wherein a control terminal is used for continuously sending the corresponding flow to a frequency conversion module according to the time in the data file; the frequencyconversion module is used for converting the flow into water pump motor frequency and sending the water pump motor frequency to a frequency converter; and the water pump motor frequency is controlledthrough the frequency converter, so that a water pump conveys water from an underground reservoir to a model forebay according to the flow change process of the unsteady flow compiled in the data file; an electric valve is arranged between the model forebay and a model downstream river channel, and the control terminal controls the opening degree of the electric valve according to the real-time flow fed back by an electromagnetic flowmeter and the real-time water level of the model forebay, so that the unsteady flow is controlled again. The unsteady flow control system is high in response speed and control precision, and the unsteady flow process of flow discharge of a power station can be accurately simulated and completely automatically controlled.

Description

technical field [0001] The invention relates to the technical field of downstream model tests of hydropower stations, in particular to an unsteady flow control system for downstream model tests of hydropower stations. Background technique [0002] During the operation of the power station, changes in electricity demand, the need for flood discharge tasks, and possible unit failures will cause changes in the discharge flow of the power station. Therefore, the power station discharges flow under various operating conditions such as peak regulation, flood discharge, and machine cut-off. Strong unsteady currents are induced in the downstream channel. As a result, problems such as steep rise and fall of the water level of the downstream river, rapid change of water surface gradient, large flow velocity variability, cross-flow and turbulent flow, and deterioration of flow state have been brought about. It is very likely to have adverse effects, thereby affecting safety, so it is ...

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Problems solved by technology

[0009] (2) The flow control is realized by adjusting the angle of the electric valve with feedback. Although this method is not easily affected by the temperature and pressure of the medium, due to the lack of mathematical analysis between the opening of the electric valve and the output flow, the actual value needs to be fed back through the flowmeter , After the comparison, the electric valve is controlled. The system structure is relatively complicated, and the response speed of flow adjustment is slow and affects the control accuracy.

However, the traditional method of manually adjusting the frequency is extremely low in automation, and it is difficult to achieve precise control of flow changes in unsteady flow processes

However, the use of host computer control through communication protocols or analog ports has a high degree of automation, but it cannot intuitively control the overall change trend of flow during the evolution of unsteady flow, and is easily affected by the number of pumps and operating voltage.

[0011] (4) At present, the unsteady flow control methods of model tests in my country mainly focus on the regular sinusoidal change or step growth of the unsteady flow rate. A method for fully automatic control of the entire unsteady flow process, while the control accuracy and response speed still need to be improved

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