Grid Supporting Inverter for Transient Load Relief in Islanded Microgrids

In islanded Microgrids the load step capability of gas engine driven Combined Heat and Power plants may be exceeded in case of a severe load step. As a result, the engine could be damaged or the generator protection system could be triggered causing a loss of generation. Such a limited robustness of system operation might render backup power supply islands useless under real world conditions. This paper presents an approach for integrating a grid supporting inverter of a battery system into a Microgrid. An existing transient droop approach is modified and then applied to achieve an adjustable transient load relief for a Combined Heat and Power plant. In case of a severe load step it can be demonstrated via simulations that the inverter is able to reduce maximum overshoot and settling time and thus to enhance the Microgrid’s robustness.