A State Variable Feedback Based Control Approach for Shunt Unified Power Quality Conditioner

The structural features and control objective of the shunt unified power quality conditioner constituted by one inverter only are analyzed.A state variable feedback based system control approach,which indirectly controls load voltage by means of controlling the supply current,is proposed,thus the problem that the undamped DC transient component of supply current,which is caused by the linking inductance between power supply and power loads under PI control mode,is solved.Using Matlab software the situations are simulated while the system is connected with linear load and nonlinear load respectively,thus the correctness and effectiveness of the proposed control approach are validated.