Novel VBHCC strategy on non-orthogonal frame for PMSM

Aiming at large switching fluctuation and wide harmonics distribution of hysteresis current control (HCC) for permanent magnet synchronous motor (PMSM), a variable bandwidth hysteresis current control (VBHCC) strategy on non-orthogonal coordinate system is proposed. The axes are decoupled with some non-zero vectors by choosing specific reference axes. The sectors are divided according to two nonorthogonal axe reference and only a specific zero vector is chosen for each sector. The current on the reference axis is directly controlled by sign function like a single-phase inverter. The hysteresis width is calculated online according to the VBHCC strategy of the single-phase inverter. And the hysteresis width is trimmed by adding a synchronous clock signal and using current error at the moment when the clock signal is triggered. Finally, the two phase switching frequencies are constant, and the third phase switching state is unchanged. The system current spectrum is similar to the that of a five-segment Pulse Width Modulation (PWM).