A hybrid RMRAC-LQR control scheme applied for power quality conditioning devices

This paper proposes a hybrid control algorithm for a power quality conditioning device. This algorithm incorporates a Linear Quadratic Regulator (LQR) to a Robust Model Reference Adaptive Controller (RMRAC) in order to obtain a high performance and robust system of control for the specified plant. The RMRAC controller is developed to deal with parametric variation and system uncertainties, while the LQR scheme is designed to deal with disturbances caused by high line impedance. Thus, the hybrid control structure guarantees a good tracking performance for the plant to be controlled, considering a huge class of uncertainties, commonly found in real systems. The power conditioning topology consists of a Shunt Active Power Filter (SAPF), that uses a three-phase three-legs Voltage Source Inverter (VSI), connected to an L filter.