On the DC Microgrid Protection

The escalating utilization of electric energy derived from burning fossil fuels has given rise to several worldwide environmental and economic apprehensions. Consequently, integrating renewable energy sources into electric grids has become imperative, thus engendering problems about dependability, safety, and quality. DC microgrids provide a promising alternative to address these difficulties due to their adaptability and ability to operate in island and network-connected modes. This makes them a viable approach for integrating distributed energy systems with the main power grid. Nevertheless, due to their unique attributes, protecting DC microgrids from failures and related challenges is a formidable task. These attributes include the absence of a zero-crossing point, low cable impedance, increasing transient voltage and current, and significant capacitance. The paper contains an overview of several approaches to detecting faults, constantly powered loads, and inverters with restricted fault current capability. Implementing grounding systems is crucial in the microgrid setting, as they play an integral part in reducing fault currents and maintaining safety. The investigation dealt with the subject matter of the difficulties and approaches involved in protecting DC microgrids. The article also elucidated several configurations of protection devices and relays. Furthermore, it is essential to emphasize the need for efficient coordination among protective devices in the direct current (DC) microgrid. Developing efficient coordination among protective devices inside the direct current (DC) microgrid has become essential for guaranteeing a reliable and robust system. This coordination entails the accurate configuration of time-current properties of protection devices and the setting up communication protocols among them. Furthermore, this paper highlights the current research gaps in DC microgrid protection.