Research on Optimizing the Configuration of Condenser in the Power Grid with Large Scale Renewable Energy

The ultra-high voltage AC/DC power supply system containing large-scale renewable energy will cause transient overvoltage of renewable energy and even serious accidents of chain disconnection after failure. Configuring a condenser in a renewable energy station or gathering station can effectively suppress transient overvoltage and improve the multi input short circuit ratio. In response to the optimization configuration requirements of the condenser in the sending end system, a mathematical model for transient overvoltage occurrence in the multi feed system and the mechanism for suppressing transient overvoltage by the condenser are first derived. Then, considering the investment cost of the condenser, an optimization model based on short-circuit ratio and transient voltage rise was established for the condenser. Finally, taking a certain sending end system of the North China Power Grid as an example, distributed and centralized condensers are configured on the 35kV side of the renewable energy grid connection and the 500kV side of the convergence station. The results show that, on the basis of optimal economic efficiency, configuring distributed condensers on the 35kV side of the renewable energy grid connection can effectively suppress transient overvoltage and improve the short-circuit ratio at the generator end, verifying the effectiveness of the proposed method.