A new digital multiple feedback control strategy for single-phase voltage-source PWM inverters

This paper proposes a new digital multiple feedback control scheme for uninterruptible power supplies (UPS) using a single-phase half-bridge inverter. The control scheme is based on sensing the current and voltage of the of the filter's capacitor. Thus, current deadbeat control is achieved, which is easy to be deduced by the discrete state equation of the LC filter. An outer voltage feedback loop with fuzzy control is also used to ensure well-regulated sinusoidal load voltage. It is shown that the control scheme, which is simple and can be designed easily, offers improved performance over the traditional deadbeat control, especially with nonlinear load. Simulation and experimental results based on a TMS320F240 (DSP) prove this.