Research on the switching method of bank of shunt capacitors in harmonic conditions

A switching method of capacitor banks with different reactance rates in harmonic case is proposed. The proposed method is combined with voltage and reactive power control (VQC). The total switching numbers of capacitor banks are determined by VQC, however, which branches should be switched is decided by harmonic conditions. The substation harmonics are divided into four cases according to the severity of the harmonics in this paper, and appropriate configuration rules of capacitor banks in different harmonic cases are studied combined with the harmonic current compensation analysis supposing the corresponding capacitor banks are switched. This paper presents strategies of capacitor banks switching in various harmonic cases, and the optimal combination of capacitor banks with different reactance rates in different harmonic cases is given with the characteristics of better harmonic compensation as well as voltage and reactive power control. Finally, the validity of the given method is tested through simulation and analysis.