This paper addresses the problems of low operation efficiency, high human resource consumption and insufficient safety guarantee of the traditional power supply system, and proposes a solution for the integration of AC and DC in intelligent substations, which realizes the. This paper addresses the problems of low operation efficiency, high human resource consumption and insufficient safety guarantee of the traditional power supply system, and proposes a solution for the integration of AC and DC in intelligent substations, which realizes the. Abstract: As a necessary power source for substations and other important power-using places, substation power supply system provides working power for important loads such as control devices, relay protection, communication equipment and fire security systems. This paper addresses the problems of. With a focus on greener power, improved eficiency and the adoption of smart-grid technologies, utility companies are upgrading from conventional substations to digital substations. Substations interconnect different voltage levels and are the critical link between transmission, distribution and. Electrical substations play a crucial role in the transmission and distribution of electricity across power systems.