In the field of power transmission, to adapt to the new energy landscape, multi-terminal DC transmission systems and DC grid technologies based on conventional and flexible DC are becoming the future development trend. Multi-terminal DC transmission enables multiple power sources and multiple receiving points, providing a more flexible and faster transmission method. Furthermore, interconnecting DC transmission lines on the DC side to form a DC grid can effectively solve problems such as active power fluctuations caused by the integration of new energy sources into the grid. It also has significant advantages in future urban smart distribution networks and microgrids, and is of great significance to the construction and development of my country's future power grid.
DC-side faults are a type of fault that must be considered in DC transmission systems, affecting the calculation of equipment parameters and the design of control and protection strategies. Compared with AC systems, DC systems have relatively lower damping, resulting in faster and deeper fault penetration, and greater difficulty in control and protection. With the development of multi-terminal flexible DC transmission systems, how to handle DC faults has become a key issue that needs to be considered in engineering practice.
In the field of power distribution, driven by modern power electronics technology and distributed power sources, DC distribution networks have enormous development prospects. On the one hand, common distributed power sources can generate DC power or be rectified to DC power. Connecting these power sources to a DC distribution network will significantly reduce the need for converter stages. On the other hand, many loads are currently powered by DC power themselves. In a DC distribution network, these loads can be directly powered without rectification, thereby reducing costs and losses. DC distribution networks offer lower line costs, lower transmission losses, and higher power supply reliability, providing numerous technical and economic advantages compared to AC distribution networks. DC circuit breakers, as DC protection devices, are of great significance in ensuring the safe operation of DC distribution networks.
In conclusion, to effectively suppress the spread of fault currents and ensure the safe operation of DC transmission and distribution networks and the normal operation of equipment, DC circuit breakers will become an effective, and even the only, technical means.