A unified series-parallel deadbeat control technique for an active power quality conditioner with full digital implementation

A number of power electronic compensators combine two or more power converters coupled to the utility in series or parallel, including the unified power quality compensator. This paper develops the concept of unified control of multiple converter systems and applies it to the compensator. The combination converters is modeled and controlled as a single multi-input multi-output system. A unified deadbeat controller controls the converter combination as one unit. The system regulates both the input current and output voltage. The unified control has improved dynamic performance over the separately controlled converter schemes commonly used, including improved disturbance rejection characteristics. The control algorithm decouples the three-phase system into two single-phase equivalents. An appropriate PWM scheme is proposed for full digital implementation. Simulation and experimental results verify the validity of the proposed control system.