A Smooth Grid Transfer Control Strategy Based on Improved Droop Control

Ensuring seamless transfer between grid-connected and stand-alone modes is crucial for maintaining a reliable power supply. This article presents a technique that allows for a smooth transition from current source control used in grid-connected mode to adopting droop control in stand-alone mode. The distributed generation unit makes use of current-source control during normal grid operation, but in the event of a grid failure, the load voltage is regulated, and load power demand is supported through power and voltage control loops. The proposed method enhances the quality of grid current and ensures consistent power output, even when voltage fluctuations occur in both grid-connected and stand-alone modes. Additionally, the technique includes current control strategies that enhance microgrid reliability during the stand-alone mode. The simulation results in various scenarios prove the efficacy of the suggested control approach.