Science and technology fields
This project belongs to the field of electrical technology. It is a discipline of power supply, power distribution, electricity consumption and electrification. It involves professional fields such as power grid operation control, power generation, energy storage, relay protection, electrical equipment, and informatization.

Main contents and characteristics
1)The architecture design of station power supply system based on microgrid is proposed;
2)Based on simulation and calculation, the optimal configuration of key components of station power supply based on microgrid is obtained;
3)Based on the coordinated application of two incoming power supplies and self-switching devices, a micro-grid based station power operation control strategy is proposed;
4)The practicality and reliability of the system are verified by building actual systems in characteristic and typical substations.

Major scientific and technological innovations
1)The architecture of station power supply system based on microgrid triple power supply guarantee is proposed. The three-layer power supply guarantee station power system structure connects photovoltaic power generation, energy storage system and charging pile into the original AC/DC integrated power system, which can not only be networked in the form of microgrid, but also greatly improve the power supply reliability of the original station power important load.
2)Based on simulation and calculation, the optimal configuration of key components of station power supply system based on microgrid is obtained.
3)Based on the coordinated application of two incoming power sources and auto-switching devices, the operation control strategy of station power with micro-grid is proposed. The control strategy of the microgrid is coordinated with the self-switching device of important loads and the segmented switch actions of segmented buses to ensure the safe and stable operation of the microgrid system and the main station power supply system;
4)Effectively solve the problem of difficulty in connecting the third line of power to high-voltage and ultra-high voltage substations, underground substations and key substations in some remote areas, and demonstrate and apply a high-reliability station power system at Disney Substation for the first time.

Social benefits and indirect economic benefits
The solar photovoltaic system and the station power load form a microgrid system to meet a certain station power load and demonstrate the concept of green energy applications. The first is to propose new solutions for station power consumption, the second is to propose new attempts to improve the reliability of substation and station power consumption, and the third is to expand the field of green energy use and promotion. By using the microgrid system in the substation, the power supply time of emergency power supply in the extreme case of power loss at the whole station is extended, and the reliability of power supply equipment is improved.
This project is the first application of new energy and related control strategies in the substation system, laying the foundation for the promotion and application of new technologies of the same type of power grid. It also promotes the application of green energy and establishes a good image of "intelligence, environmental protection and green" for power companies. Played a positive role.

application
It has been promoted and applied to the station power supply system of 110 kV Disney Smart Substation. Under normal circumstances, the transformers of the two stations supply power to two sections of 400V bus respectively. When one of the stations loses power and the important load is switched to the other section of bus by the self-switching device, no power outage will occur. When both power transformers at both stations lose power, the loads hanging on the I and II buses lose power briefly, and the microgrid enters islanding mode. First, it supplies power to important loads, and supplies power to some non-important loads when the photovoltaic power generation output and energy storage capacity are abundant. When power supply in the station is restored, the microgrid is connected to the grid again and returns to normal operating mode. When one of the stations uses a transformer for maintenance, the section switch can be manually closed, and the transformer can use two sections of buses for one station to maintain normal power supply to the load. Whether one station transformer loses power or both stations loses power, the station power microgrid system can smoothly switch between different operating modes, ensuring the power supply to important loads in the station and improving the power supply reliability of key loads.