Performance and power quality improvement based on DC-bus voltage regulation of a stand-alone hybrid energy system

This paper proposes an improved standalone configuration based on hybrid wind-PV with Lithium-ion battery bank combined with a Shunt Active Power Filter (SAPF). The hybrid system is controlled to produce the active power and to supply the load by a good power quality. The main idea of this novel configuration is to control the SAPF only to compensate the harmonic currents. In fact, the SAPF DC-side voltage and the PV system are directly connected to the common DC-bus of the hybrid system, which is regulated by the batteries through a buck-boost converter (BBC). Due to its regulation through a large Battery Energy Storage System (BESS), good dynamic response of the DC voltage is obtained, during a sudden variation in nonlinear load. Hence, the SAPF capabilities of harmonic filtering are enhanced. In addition, the proposed system is controlled to operate at the maximum power point under abrupt conditions, and to meet the load demand and maintain the output voltage and frequency at their desired values despite changes in load conditions. Finally, the SAPF performances are demonstrated through a comparison with a conventional configuration of the SAPF on various indices.