An Improved Droop Controller for Three-phase Multi-junction Inverters in the Micro-grid

Three-phase multi-function inverters (TPMFIs) are able to generate active power and improve the power qualities of micro-grid simultaneously. However, to cope with the frequently switching of loads in micro-grid, the self-adaptive control of the output power of the TPMFI is also required. Therefore, an improved droop controller is proposed in this paper. The proposed controller concludes a modified allocation strategy of output power for TPMFIs in micro-grid, and a switching controller for power quality detection function. By adopting the proposed droop controller, the TPMFIs in the micro-grid could compensate the power quality problems in real time and self-control the power output at the same time. Verified by Matlab/Simulink simulations, the proposed droop controller for TPMFIs could guarantee the stability of microgrid and enhance the power quality of micro-grid at the same time.