A comprehensive review of HVDC circuit breakers and protection systems

The recent evolution of electrical systems, coupled with the rapid expansion of renewable generation sources, has encouraged the rapid growth of high-voltage direct current (HVDC) to transmit high power over long distances. In particular, for the future implementation of DC grids, the development of DC breakers is needed to ensure selectivity in fault elimination while ensuring reliability of the power system. The absence of current zero crossings, as occurs periodically in AC, which are essential for arc extinction, makes it impossible to use standard mechanical switches. In addition, the use of modern Voltage Source Converter (VSC), requires DC circuit breakers to perform very high in terms of fault extinguishing time. This paper provides an overview of the main DC switch technologies and their operation, examining advantages and limitations of each type with references to prototypes and real applications.