A new LQR modeling approach for power quality conditioning devices

This paper proposes a new modeling approach for power quality conditioning devices. This modeling allows the use of LQR controllers with better accuracy. It is due to the incorporation of the grid voltages mathematical model, usually considered as disturbances, in the description of the plant to be controlled. This method is feasible thanks to a reference generation scheme, recently proposed by the authors, based on the optimum filtering theory which provides the state space variables needed to represent the new plant state space model proposed. The reference generation mentioned above also provides references for harmonics cancellation, displacement power factor correction and unbalance compensation. The power conditioning topology consists of a battery energy storage system (BESS), that uses a three-phase three-legs shunt Voltage Source Inverter (VSI) and a battery bank.