Constant switching frequency hysteresis controller for VSI fed Induction Motor drive using current error space phasor approach

A simple current error space vector (CESV)based constant switching frequency hysteresis controller for two level voltage source inverter fed Induction Motor(IM) drives is proposed in this paper. The main advantages of space phasor based hysteresis controllers such as fast dynamic response, adjacent voltage vector switching can be seen in the proposed controller. In addition to these, switching frequency variation can be eliminated substantially. The stator voltages estimated from the current ripple, calculation of vector switching times and voltage error vectors are used for the current error boundary calculation. The proposed controller selects only those inverter voltage vectors of the present sector which are adjacent to the machine voltage vectors for the entire range of operation to reduce current error. Bus clamping space vector pulse width modulation(BCSVPWM) is used for vector selection logic where only one zero state is used in a sub cycle of total switching time period. The proposed hysteresis controller based inverter fed drive scheme is simulated using SIMULINK toolbox of MATLAB for steady state and transient performance.