Control of Custom Power System Devices

In this book, a three-bus, radial distribution system is proposed to be used as a benchmark for the study of power quality problems (PQPs) and their compensation. To mitigate PQPs in distribution systems, Custom Power Systems (CUPS) devices such as Distribution Static Compensator (D-STATCOM), Dynamic Voltage Restorer (DVR), and Unified Power Quality Conditioner (UPQC) are required. An increasingly popular and practical control technique based on Active Disturbance Rejection Control (ADRC), which is simple and has good disturbance rejection capabilities, is implemented to control CUPS devices. Its performance is compared with the highly dominating Proportional-Integral-Derivative (PID) controller. Modelling of the DVR and the D-STATCOM, together with their respective ADRC and PID controllers, were developed under the MATLAB /Simulink environment. Simulation results, which included voltage sag/swell, voltage imbalance and current imbalance, proved that the ADRC controllers are attractive for their use with CUPS devices to mitigate the PQPs and can be considered as effective replacements for the PID controller.