A Voltage-Droop-free Reactive Power Sharing Solution in Microgrids

The proper active and reactive power sharing is one of the fundamental control targets for distributed generators in microgrids. Currently, the most common solution is to use the active power-frequency (P-f) and reactive power-voltage (Q-V) droop control. In this paper, a virtual impedance based reactive power sharing solution is proposed as an alternative to voltage droop for reactive power sharing among paralleled units in a microgrid. By adopting the new proposal, the active and reactive power sharing will be naturally less sensitive to the R/X ratio, while the reactive power sharing performance is as good as conventional voltage droop control. In addition to that, the two methods are compared to unveil the inner connection. In order to validate the effectiveness of the proposed method, comparative experiments are carried out and the experimental results are consistent with the analytical results.