Adaptive compensation of inverter non-linearities based on the Kalman filter

In this paper, a novel adaptive compensation strategy to reduce dead-time effects and nonlinearity of the VSI is presented. These undesirable properties of the inverter are necessary to compensate because they cause 5th and 7th harmonic distortion of the phase current, torque pulsation and generally reduce the effectiveness of control algorithm. The observer which estimates the dq-currents and the value of the voltage error by only one parameter is designed based on the harmonic analysis and algorithm of the Extended Kalman filter. Subsequently, the compensating voltages are determined from estimated voltage error and the polarity of the estimated currents. The results of simulations and real experiments demonstrate the effectiveness of the proposed approach.