Dead-beat predictive direct power control of voltage source inverters with optimised switching patterns

This study presents a novel dead-beat predictive direct power control (PDPC) strategy working at nearly constant switching frequency for the voltage source inverter. The proposed strategy employs two active voltage vectors and one null voltage vector during every control period. To solve the problem of negative predicted duration time of active voltage vectors in the conventional dead-beat PDPC strategy, an automatic updating mechanism is designed. When the predicted duration time is negative, the applied voltage vectors will be updated automatically without the need of reselecting voltage vectors or recalculation of the duration time. Accurate tracking of both active and reactive power can be achieved with small power ripples using the strategy proposed in this study. The proposed PDPC strategy shows excellent steady performance and fast dynamic responses. High sampling frequency can also be avoided and the calculation process is simple enough to be implemented on normal DSPs. Simulation and Experimental results are presented to validate the feasibility of the proposed dead-beat PDPC strategy.