Novel discrete-time predictive current regulators far parallel resonant DC link inverter

This paper presents two kinds of novel discrete-time current control methods for induction motor drives that are fed by a parallel resonant DC link inverter (PRDCLI). The methods are based on using both the modified fixed band hysteresis control and optimal control. Since zero bus voltage intervals are generated on the DC link of PRDCLI, the counter electromotive force of an induction motor and the average value of the DC link voltage can be estimated. Based on the previously estimated values, the proposed current regulators predict the phase currents of one and/or two-step ahead resonant cycles. The computer simulation result shows that the proposed control schemes offer not only the advantage of zero-voltage-switching resonant inverters but also a reduced total harmonic distortion compared with conventional current regulators.