Smooth Pulse Number Transition Strategy Considering Time Delay in Synchronized SVPWM
Joon-Seok Kim, Do-Hyeon Kim, June-Hee Lee, June-Seok Lee
Abstract
In high power motor drive systems, synchronized space vector pulsewidth modulation (synchronized SVPWM) is widely used to guarantee stable control performance. Synchronized SVPWM has a characteristic that the switching frequency varies abruptly when the pulse number transitions. This article proposes a pulse number transition point at which the phase difference is minimized to remove the phase difference of the sampling point that appears during synchronized SVPWM control. In addition, for a smooth pulse number transition of synchronized SVPWM, a compensation method for the magnitude and phase error of the inverter output voltage due to the time delay and a method of removing the existing phase difference without using a phase-locked loop are proposed in consideration of the characteristic of changing switching frequency. The validity and the implementation of the proposed method are verified by experimental results using a high-power inverter driving 332 kW interior permanent magnet synchronous motor (IPMSM).