Model predictive pulse pattern control with very fast transient responses

Closed-loop control and modulation of AC drives with offline computed optimized pulse patterns can be achieved by manipulating the time instants of the switching transitions. During torque steps, faults and low-voltage ride through operation, however, the transient response time is often rather slow, due to the absence of an appropriate voltage vector. By inserting additional switching transitions, deadbeat-like control can be achieved. The resulting control scheme combines the merits of optimized pulse patterns and deadbeat control, by providing very low current distortions at steady-state operation and very short response times during transients. Simulation results highlighting this are provided for a five-level inverter drive system.