Abstract:

An effective solution to reduce the single-phase short-circuit current is to install small reactors on the neutral points of 500 kV autotransformer. In the course of engineering, the AC and DC components on the neutral points of main transformer should be studied, as well as the transient voltage during switching process, in order to determine the switch mode of the small reactor. Taking the installation of small reactors in a 500 kV substation as an example, the characteristics and sources of the AC and DC components were analyzed through the recorded data on the neutral point. The simulation research was carried out to analyze the change of transient voltage during the switching process of the small reactors, and finally the parameters of the earthing switch used on the neutral points were suggested.

Key words: small reactor on neutral point, switch mode, AC and DC components, transient voltage, earthing switch on neutral point