DC Bus Current Sensed Space Vector Pulsewidth Modulation for Three-Phase Inverter
Yongpeng Shen, Zhufeng Zheng, Qiancheng Wang, Pu Liu, Xiaoliang Yang
Abstract
The dc bus current sampling technology with the traditional space vector pulsewidth modulation (SVPWM) scheme imposes several challenges, particularly at the low-modulation region and sector boundaries, where the duration of a nonzero vector may be so short that the phase current cannot be measured reliably. A new dc bus current sensed SVPWM (SSVPWM) method is proposed, in this article, to overcome shortcomings of the traditional algorithm. By introducing the concept of minimum sampling time, the unobservable area of the dc bus sampling system is divided accurately. Then, the SSVPWM and associated current reconstruction strategy are proposed by inserting the measurement vector and the compensation vector. Finally, experiments were performed on a 2.7-kW permanent magnet synchronous motor (PMSM), and the experimental results showed that the current sampling error of the proposed SSVPWM is less than 2% and the THD of three-phase current is less than 4.9%, which provides accurate current feedback for high-performance vector control.