Digital adaptive hysteresis current control with clocked commutations and wide operating range

A new hysteresis current control technique of voltage source inverters is proposed, which uses digital calculation to predict the proper band amplitude in order to minimize the error and give a switching frequency synchronized with a clock. The technique is self-adapting to supply and load parameters, and is easily extended to three-phase systems using the decoupling approach already proposed by the same authors. The proposed technique exhibits both the advantages typical of the hysteresis methods, and those of the digital controls. The implementation of the control is done by means of a standard microcontroller and simple additional circuitry. Simulations and experimental tests confirmed the advantages and the excellent performance of the new modulation method.