Optimal design and control implementation of unified power quality conditioner

In the modern microgrids systems, it is essential to compensate the power quality problems in the systems to avoid the potential breakdown and damages of power system components. In order to solve all the power quality issues in the microgrids, increasing attention has been paid to the unified power quality conditioner (UPQC) system which can improve power quality at both the source and load sides. In the conventional UPQC-P, the series converter only handles the active power, while the shunt converter handles all the load reactive power. In order to coordinate the reactive power between the two converters, the variable phase angle control (PAC) method is applied in the controller. The series converter can thus be fully utilized during the operation. Based on the variable PAC method, the maximum utilization rates of the power converters and the optimal capital cost of the UPQC system are investigated in this thesis.Doctor of Philosophy (EEE