Diesel generator slow start-up compensation by supercapacitor for DC microgrid power balancing

By aggregating renewable sources as main generators, storage systems, diesel generator, and loads, microgrids can achieve high level renewable energy penetration and efficiency in electricity distribution systems. The difference between loads consumption and renewable generation causes fluctuations in the microgrid bus voltage. For off-grid operating mode or limited public grid availability, power balance is performed by adjusting storage and diesel generator power for voltage stabilization. However, due to the slow dynamic behavior of the diesel generator, especially the start-up stage, the power quality is lowered down during the sudden load power increase or sudden renewable power decrease. So, the microgrid power balancing needs to be compensated by a fast response storage. This paper focuses on diesel generator slow start-up dynamic compensation by supercapacitor for DC microgrid power balancing. Based on simulation results, this study shows that the designed control strategy improves the microgrid dynamic characteristics under such operating conditions.