The influence of parallel capacitor to output voltage in high-frequency ESP power

High frequency power supply has been widely used in electrostatic precipitator (ESP) systems. High level of parasitic capacitance is generated in the windings of the transformer, which is used to boost voltage to around one hundred volt. The stray capacitor can be treated as a capacitor in parallel with primary winding of the transformer. Due to the parasitic capacitance of the high voltage transformers, the topology of the converter in ESP systems is actually LCC resonant converter rather than LC resonant converter. Analysis of four operating modes of the LCC resonant converter, and the calculation of the series inductance, series capacitors, shunt capacitance value are presented in this article. The influence of parallel capacitance to output voltage is analyzed and verified by experiment as well. The results provide the theoretical basis and guidance for the analysis, design and control of the high voltage resonant converters with parasitic capacitance, which especially presents a good application value for engineering of capacitor charging and electrostatic precipitator supply.