Study on harmonic source model of millisecond pulsed power load based on switching functions

Abstract

Modern radar is a typical millisecond pulse power load (MPPL), which contains a large number of power electronic devices. If the MPPL is connected to the power system, it will cause serious voltage distortion problems. The working mode of the radar pulse load will directly affect the voltage distortion. In order to analyze the influence of MPPL on the system voltage distortion, a harmonic source model of MPPL were proposed based on the switching functions. At the same time, in order to evaluate the degree of voltage distortion, an improved voltage distortion evaluation index-Waveform Relative Deviation Rate (WRDR) is proposed. The harmonic source model is based on the equivalent topology of MPPL, which can theoretically explain the cause of the sub-harmonic and inter-harmonic currents, and can reflect the influence of the parameters of MPPL on its harmonic characteristics. The simulation and experimental results prove that the harmonic source model can be used to calculate the distribution and magnitude of the harmonic current of MPPL, and to explain the cause of voltage distortion. Finally, the improved voltage distortion evaluation index is used to analyze and summarize the influence of MPPL on voltage distortion.