An Enhanced Shunt Active Filter with Energy Storage for Microgrids

This paper investigates the use of energy storage added to a shunt active filter configuration in order to enhance its operation in maintaining power quality conditioning at a particular part of a grid system. The specific application considered is for a microgrid. In the proposed configuration the shunt active filter with energy storage (SAFES) can supply both reactive and real power for a short duration, to "fill in" the power required in the presence of load changes within the microgrid until the main generation can respond. In this way voltage quality is maintained and no power is drawn from the main grid. To perform both voltage and harmonic compensation in the presence of a non-linear load a novel control strategy based on the state space pole placement design has been developed for the SAFES installed in a microgrid. Simulation studies and experimental results show that the proposed controller is able to regulate the grid voltage at its nominal value and also control the power sharing between the SAFES and the local supply. It also provides high bandwidth control of current harmonics.