This paper shows the motivation towards the development of a dq-Proportional Resonant (PR) control strategy in shunt active power filter design for eliminations of distortions in source currents for different loading conditions. The switching signals for the inverter of shunt active power filter (APF) have been generated by the hysteresis current control scheme. The controller performance has been verified by using different types of loads such as non-linear balanced, unbalanced and variable etc., with the system in MATLAB/Simulink environment. An experimental prototype has also been developed in the laboratory and results are analyzed to validate the efficacy of the proposed controller.

In this article, we introduce an active power distribution scheme for a grid-interactive hybrid microgrid system. To address the effect of climatic change on power generation from renewable energy sources, a combined energy storage unit (CESU) consisting of both battery and supercapacitor is employed in this study. An improved mixed droop technique (IMDT) is designed in this article to split the total power requirement in the microgrid into transient and average components for smooth power handling by the CESUs. A robust sliding-mode nonlinear controller (SMC) is implemented instead of the conventional propotional integral (PI) controller for the switching regulation of the dc/dc bidirectional converters connected across the CESU. Hence, a hybrid control algorithm is developed in this article by combining both IMDT and SMC for the distribution of active power among solar photovoltaic (PV), combined storage units, utility grid, dc load, and both linear and nonlinear ac loads. The performance adaptability of the proposed method is supported by both MATLAB simulation results and the results taken from laboratory-developed prototypes.

Microgrid has emerged as an effective solution for incorporation of distributed energy resources (DERs) to suffice the intensifying energy demand, meanwhile contributing towards sustainable development of power sector. However, with this progressive transformation, the quality and reliability of power is significantly affected particularly in the remotely placed low voltage small-scale microgrid due to its low inertia. Therefore, the proposed work focuses on the performance improvement of low voltage microgrid by integration of photovoltaic (PV) and battery energy storage system (BESS) fed unified power quality conditioner (UPQC). The control scheme of UPQC is deliberated to deliver multiple benefits of power quality improvement, maximum deployment of PV by employing BESS, reduced burden on grid and swift regulation of DC-link voltage under various system dynamics. Hence, eliminates the requirement of extra converter for interfacing PV and BESS with grid. Additionally, a switch protection strategy is incorporated in UPQC control algorithm. Without any modification in the system configuration and capacity, it prevents the UPQC switches from damage due to very high magnitude of current during any load induced uncertain scenario. BESS controller operates by using dynamic battery reference power which is updated with respect to the dynamics of load demand, PV power and battery state of charge (SOC). Evaluation of the proposed system is performed through MATLAB/Simulink and experimental prototype by imposing various dynamics conditions.