Six-step operation of PMSM with instantaneous current control

Six-step operation has many advantages on PMSM drives. Because the fundamental of inverter output is maximized by the six-step operation, capability of machine can be a lot enhanced. Furthermore, switching loss of inverter can be minimized by the six-step operation. Despite many merits of the six-step operation in AC machine drives, it was rarely adopted in dynamic applications because performance of current control is severely degraded during the six-step operation. In this paper, a control scheme for the six-step operation of PMSMs is proposed. Applying the proposed method, the six-step operation is successfully realized without losing control dynamics.