Improved droop control of parallel inverter system in standalone microgrid

The standalone microgrid describes the condition that isolated from the utility system. Inverter parallel operation is the key issue of standalone microgrid. The objective of the parallel inverter system is to realize the load sharing between inverters and keep the voltage and frequency stable under different load conditions and during load variations. This paper employs the double-loop control method to obtain stable voltage and frequency with droop control method for load sharing. According to the characteristics of the low voltage transmission line, the linear transformed droop control method is applied. Improvement of the droop control is proposed to keep the voltage more stable. The proposed control strategy is verified by the simulation and experimental results.