Harmonic analysis and filter design based on high power electromagnetic transmitter

Abstract

Abstract In order to effectively suppress the higher harmonics contained in the output voltage of high-power electromagnetic transmitter, the waveform expression of the output voltage of bipolar pulse width modulation (SPWM) circuit is derived, which can accurately obtain the fundamental wave and each harmonic content in the inverter bridge transmission voltage, and provide a theoretical basis for the design of output filter. At the same time, a design method of output LC filter based on high power electromagnetic transmitter is proposed based on MATLAB simulation calculation and considering the fundamental voltage drop, inductor current ripple and reactive power capacity on the filter inductor. Finally, the feasibility of this design method is verified by the field experiment of transmitter, and the output filtering effect is good.