Simulation of surplus harmonics in selective harmonic elimination technique

Selective harmonic elimination technique can eliminate any order harmonics theoretically, but it is restricted by the initial value of switching angles and the switching speed of power device, therefore, it has surplus high-order harmonics. The surplus harmonics exist in the form of harmonics group, there is a window which harmonic wave amplitude close to zero between the adjacent harmonic group. The surplus harmonics influence the stability of power equipment, by analyzing it's distribution regulars we can learn about the disadvantageous influence on electric equipment. The factors influencing surplus harmonics distribution regulation in selective harmonic elimination technique are mainly the selection of initial value of switching angles, the number of switching angles, the fundamental waveform amplitude etc. By theoretically calculating and emulating, analyzing the surplus harmonics in selective harmonic elimination technique, so as to establish the theoretical basis for its' practical application.