An Improved Control Strategy to Reduce Operating Hours of DG Genset in Solar PV-BES-DG Based AC Microgrid

Abstract

The diesel-engine (DG) Genset-based microgrids are extensively used in remote areas. However, DG Genset 24 hours operation increases the overall cost of electricity and also pollutes the environment, diminishing the main purpose of renewable energy-based microgrids. However, the microgrid's dependency on the DG Genset cannot be eliminated, but it can be minimized by using a proper control strategy. By focusing on it, this work presents an improved control strategy to reduce the DG Genset's working hours in a solar photovoltaic (SPV) battery energy storage (BES) and DG Genset-based microgrid. The designed scheme is based on a set of rules, which are formulated by checking the status of the SPV array generation, BES, and load demand, and accordingly operates the microgrid with DG Genset or without DG Genset modes. Compared to the existing state-of-the-art scheme, the designed scheme operates the DG Genset during only an emergency, reducing its overall working hours. In addition, it provides a stable microgrid operation compared to the existing scheme, when the microgrid's operating mode is shifted from one to another. Besides, DG Genset is operated at its rated power with a unity power factor, giving maximum fuel efficiency. Its power quality performance is also monitored and ensured that the IEEE std. 519 does not defy in case of nonlinear/unbalanced loading. To improve power quality, the designed control scheme uses the cascaded generalized second-order integrator (C-SOGI) based phase-locked loop (PLL). A comprehensive simulation study is performed to show the advantages of the developed scheme over the existing schemes, which is supported by experimental results.