Control Strategy for a Three-Phase DC-AC Converter with an Output LCLC Filter that Feeds an Unknown Load Current Source

This paper presents a control strategy for a three-phase DC-AC converter with an output LCLC filter that feeds an unknown current load. The main purpose is to improve the performance of the system under sudden changes in the load while the output voltage follows a reference giving by the designer. To obtain a quick response, a feedforward and PR controller is proposed, which includes a compensation that estimates the current load, its first derivative and two states of the filter. To get this estimation, virtual sensors are used. With this, the use of four sensors is avoided. Simulation results are presented to show the performance of the proposed controller