Engineering Method to Select Parameters of Single-Tuned Filter Capacitor

During engineering design there may exist blindness in the selection of rated capacity and rated voltage of single-tuned filter capacitor.To fully utilize the economic effect brought about by increasing rated capacity of filter capacitor and to filtrate harmonics better,the authors derive the relational expression among rated capacity of single-tuned filter capacitor with its rated current and harmonic currents as well as practicable formulae to determine rated parameters of the capacitor.Taking the arithmetic sum of fundamental harmonic and harmonic voltages as verification condition,a formula to select capacitor's lowest rated voltage is given.On the basis of calculation examples,corresponding parameters of the filter capacitor are proposed according to the proposed formulae.The impedance-frequency characteristics of a filter set constituted by three parallel filtering branches shows that the proposed formulae are correct and rational.