Integrated protection and monitoring system for safe operation of photovoltaic-based isolated microgrids

The task of electrifying isolated zones involves several requirements that must be attended. One option to fulfil this task is by using isolated microgrids to energize zones typically disconnected from the main grid. The high penetration of variable energy resources and their corresponding power-electronics-based interfaces make the operating conditions of isolated microgrids considerably different than the operating conditions of large-scale power systems. Consequently, one of the most important challenges of microgrids is the design of the protection system, i.e., the traditional protection schemes should be rethought to respond adequately to safety requirements of isolated microgrids. In this paper a novel methodology for the protection of photovoltaic-based isolated microgrids is presented. This scheme responds to changes in the operation conditions, adjusting the protection devices settings to deal with fault events and maintain a safe operation. This proposal is tested through an experimental setup and simulations, showing better results than the other protection schemes.