Equilibrium point based alternative inverter control design and low-dimension estimator for inductor current

Different from the traditional controller for alternative inverter whose output is sinusoidal, the equilibrium point is proposed based on the voltage/capacitor-current model. A novel controller is presented and the sinusoidal-tracking problem is changed into the one which drives the tracking error to zero. The system stability has been discussed in details. Since the capacitor current is small which could result in poor precision or high cost of current sensors, based on the voltage/inductor-current inverter model, a novel current estimator is proposed. The estimator is a 1-dimension equation instead of a full-dimension one with variables coupling. It is simple and the computation burden is smaller. The results have been verified by simulation and experiment results at last.