Analysis of Harmonic Characteristics of Pulse Load Based on Switching Functions

Abstract

As a kind of special nonlinear load, pulse load (PL) has the characteristics of two typical nonlinear loads. Compared with the traditional rectifier load, the harmonic characteristics of the PL are more complicated. In this paper, the harmonic characteristics of the PL is investigated. By analysing the working mode of the PL, an equivalent circuit model and a switch function model of the PL are introduced. It is analysed that the PL will inject a large number of inter-harmonics and even sub-harmonics in addition to the integer harmonics to the power system, and the harmonics are symmetrically distributed. The experiments were conducted on diesel generator sets (DGS) with PL and public grids with PL. The results show that the established model and analysis method can accurately calculate the harmonic distribution of the system, moreover, the influence of PL mode on harmonic characteristics can be revealed.