Power Factor Correction of Three-Phase PWM AC Chopper Fed Induction Motor Drive System Using HBCC Technique

Abstract

In this paper, a new control strategy for an induction motor (IM) drive system fed from three- phase pulse width modulation (PWM) AC chopper is proposed. The main objective of the proposed control scheme is to achieve input power factor correction (PFC) of the IM drive system under different operating conditions.  PFC  is  achieved  by  continuously  forcing  the  actual  three-phase  supply  currents  with  the corresponding reference currents,  which  are  generated  in  phase  with  the  supply  voltages,  using  hysteresis band current control (HBCC) technique. The proposed control strategy has two loops; inner and outer loop. Output of the outer loop is the magnitude of the supply reference current resulting from either speed controller or startup controller, whereas output of the inner loop is PWM signals of the AC chopper. The proposed AC chopper features a smaller number of active semiconductor switches; four IGBTs, with only two PWM gate signals. As a result, the proposed system is simple, reliable, highly efficient and cost-effective. Mathematical analysis of the drive system is presented. Components of the input LC filter are designed using frequency response. The IM drive system is modeled using MATLAB/SIMULINK and a laboratory prototype was built and  tested.  Simulation  and  experimental  results  confirm  validity  and  robustness  of  the  proposed  control strategy.