A Power Sharing Control Method of Parallel Hybrid Inverters to Preserve Microgrid Stability

Photovoltaic power generation is green, but its power is fluctuant. Energy storage system can balance the contradiction between photovoltaic power generation and load power consumption by charging and discharging management. Therefore, the control and management of microgrid composed of hybrid inverters and PV inverters in parallel has become a research hotspot. The power output ability of each hybrid inverter in microgrid is different because of the different capacity of PV panel, illumination condition, and capacity and SOC of battery. So it is necessary to recognize the actual power capacity of each inverter and control the output power reasonably. This paper analyses the characteristics of parallel inverters in microgrid based on droop control, then raises the method to identify the power balance state of every inverter by detecting DC bus voltage and control the output power of the inverters by adjusting the droop control parameters. The simulation and experimental results show that the output power of every inverter could be adjusted in time based on actual power ability, and the load power demand can be met. Above all the power balance of the microgrid system can be achieved using this method.