Decentralized Master–Slave Control for Series-Cascaded Islanded AC Microgrid

Series-cascaded Microgrids (MGs) are gaining increasing popularity because of their control flexibility and ability to synthesise high voltage levels from low power rated modules. Several control schemes have been reported for autonomous power sharing in series cascaded microgrids that incorporate dispatchable Distributed Generators (DGs) only. In contrast, this paper develops a series cascaded microgrid formed by dispatchable and non dispatchable DGs. Achieving power balance as well as voltage and frequency regulation in this microgrid configuration is a challenging task. This work proposes a decentralised master slave control scheme that regulates voltage and frequency and maintains power balance. The proposed scheme ensures maximum utilisation of non dispatchables, incorporates autonomous power curtailment under light load conditions, and offers system reliability comparable to the traditional parallel structure. The proposed microgrid configuration and control scheme are thoroughly validated via simulations and experiments under various operating scenarios.