Study on a switching-pattern hysteresis current control method based on zero voltage vector used in three-phase PWM converter

The conventional hysteresis current control (C-HCC) method has a fast transient response and good robust performance. However, due to interphases dependency among the three-phase currents, several shortcomings, for example, a high-switching frequency and large cycle current oscillation will arise inevitably when C-HCC is applied in a three-phase pulse width modulation (PWM) voltage-source converter (VSC). First, this study gives a review on the space vector-based HCC (SV-HCC) which is researched to overcome the shortcomings of C-HCC. The SV-HCC can avoid the most shortcomings of C-HCC. However, SV-HCC has more hysteresis comparator and the adjustment process of hysteresis band (HB) is fussy. In addition, the switching numbers of the three-phase bridge-legs are unbalanced. Then, a switching pattern (SP)-based HCC method is presented in this study which refers to the concept of zero voltage vector in space vector PWM (SVPWM). The presented method set an HB which depends on the system parameters. In the presented method, zero-vector SP will be selected when the three-phase current errors are all within the given HB, and conversely, the specified switching logic will be selected when the current error exceeds the HB. Finally, the effectiveness and superiority of the presented method are verified by simulation and experiment tests.