A self-adaptive space phasor based hysteresis current controller with switching of adjacent inverter voltage vectors for three-level voltage source inverter fed induction motor drive

A current error space phasor based hysteresis controller is proposed for three-level voltage source inverter fed induction motor drive. Only the adjacent inverter voltage vectors forming a triangular sector, in which tip of the machine voltage vector lies, are switched to keep the current error space phasor within the hexagonal boundary. Calculation of the machine voltage vector is not needed and information of the same is derived from current error space phasor direction. The controller is self-adaptive and provides smooth transition between voltage levels, including operation in over modulation region. Inherent advantages of current hysteresis controller are retained. The proposed controller is implemented on a 1.5 kW open-end winding induction motor drive. Usage of the proposed controller can be extended for further levels of multi-level inverters for high performance drives