A Control Method for Suppressing Subsynchronous Resonance of Wind Farm Series Compensation Transmission System

Abstract

The invention relates to a control method for suppressing sub-synchronous resonance of a wind power station series compensated transmission system, and particularly provides a sub-synchronous resonance control method based on a high-power power electronic converter. According to the invention, series compensated line current signals or series compensated capacitive voltage signals are measured at first to act as input signals, sub-synchronous voltage reference signals are acquired through signal processing, the sub-synchronous voltage reference signals are inputted into a high-capacity power electronic converter so as to generate actual sub-synchronous voltage, and the sub-synchronous voltage is coupled to the series compensated transmission system through a transformer which is connected to the series compensated line in series. Therefore, the power electronic converter is equivalent to a pure resistor connected in the line in series at the sub-synchronous frequency where resonance occurs, and resonance energy is consumed, and SSR (sub-synchronous resonance) is suppressed; and the power electronic converter is equivalent to a short circuit at the power frequency, and the power frequency operating state of the system is ensured to be constant.

Description

technical field [0001] The invention relates to a control method for suppressing subsynchronous resonance of a series compensation transmission system of a wind farm, and in particular proposes a subsynchronous resonance control method based on a high-power power electronic converter. Background technique [0002] In recent years, my country's wind power generation has continued to develop rapidly. Among them, doubly-fed wind turbines have been widely used because of their flexible control and the ability to achieve variable speed and constant frequency. At present, my country has built many large-scale wind power bases of 10 million kilowatts, and the delivery of large-capacity wind power has become a technical problem. The series capacitor compensation of the transmission line can reduce the line reactance equivalently, improve the transmission capacity of the line and the transient stability of the system, and provide a new idea for solving the problem of large-scale wind...

AI Technical Summary

Problems solved by technology

At present, some scholars have proposed to suppress the SSR of wind farms by adding a subsynchronous damping control loop to the double-fed wind turbine converter (rotor-side converter or stator-side converter). However, the capacity of the double-fed wind turbine converter is small. The SSR suppression capability of the method is also limited

Since the mechanism of wind farm SSR problems is very complex and there are many related influencing factors, how to effectively suppress wind farm SSR problems has not yet been solved.

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