A self-adaptive power balance control strategy for PV inverters in islanded microgrids

Abstract

For photovoltaic inverters in islanded microgrids, droop control is a preferable strategy due to its attractive ability in bus voltage regulation and load sharing without additional communication system. However, in islanded microgrids without redundant storages, further realization of power balance between droop controlled PV sources and dynamic loads, which is beneficial to enhance PV sources penetration and system reliability, remains a serious problem. This study focuses on this issue and improves conventional droop control method with self-adaptive power balance strategy. The proposed droop method can promise stable operation when total load consumption is under maximum capacity of all PV sources, which means PV arrays quit maximum power point and shift in accordance with load demands to avoid large storage component at dc-side of inverters while keeping voltage regulation ability from droop control.