To meet the fast-growing energy demand and, at the same time, tackle environmental concerns resulting from conventional energy sources, renewable energy sources are getting integrated in power networks to ensure reliable and affordable energy for the public and industrial sectors. However, the integration of renewable energy in the ageing electrical grids can result in new risks/challenges, such as security of supply, base load energy capacity, seasonal effects, and so on. Recent research and development in microgrids have proved that microgrids, which are fueled by renewable energy sources and managed by smart grids (use of smart sensors and smart energy management system), can offer higher reliability and more efficient energy systems in a cost-effective manner. Further improvement in the reliability and efficiency of electrical grids can be achieved by utilizing dc distribution in microgrid systems. DC microgrid is an attractive technology in the modern electrical grid system because of its natural interface with renewable energy sources, electric loads, and energy storage systems. In the recent past, an increase in research work has been observed in the area of dc microgrid, which brings this technology closer to practical implementation. This paper presents the state-of-the-art dc microgrid technology that covers ac interfaces, architectures, possible grounding schemes, power quality issues, and communication systems. The advantages of dc grids can be harvested in many applications to improve their reliability and efficiency. This paper also discusses benefits and challenges of using dc grid systems in several applications. This paper highlights the urgent need of standardizations for dc microgrid technology and presents recent updates in this area.

为了满足快速增长的能源需求，同时解决常规能源引起的环境问题，可再生能源已集成到电力网络中，以确保公共和工业部门获得可靠且负担得起的能源。但是，将可再生能源整合到老化的电网中可能会导致新的风险/挑战，例如供应安全，基本负荷能量容量，季节性影响等。微电网的最新研究表明，由可再生能源提供燃料并由智能电网进行管理（使用智能传感器和智能能源管理系统）的微电网可以以经济高效的方式提供更高的可靠性和更高效的能源系统。通过利用微电网系统中的直流配电，可以进一步提高电网的可靠性和效率。直流微电网是现代电网系统中的一种有吸引力的技术，因为它与可再生能源，电力负荷和储能系统具有天然的接口。在最近的过去，在直流微电网领域的研究工作有所增加，这使该技术更接近于实际实施。本文介绍了最新的直流微电网技术，涵盖了交流接口，架构，可能的接地方案，电源质量问题和通信系统。直流电网的优势可以在许多应用中获得，以提高其可靠性和效率。本文还讨论了在几种应用中使用直流电网系统的好处和挑战。本文强调了直流微电网技术标准化的迫切需求，并提出了该领域的最新进展。