Interruption technologies for HVDC transmission: State-of-art and outlook

Research on direct current (dc) interruption has grown in recent years, driven by increased interest in using high voltage direct current (HVDC) for large power transmission and future grids. In fact, dc interruption poses particular challenges to protection devices and circuit breakers and new technologies are needed to meet the requirements of future HVDC grids. In this paper we review some of the traditional and innovative dc interruption technologies for HVDC applications. The discussion addresses aspects such as speed of operation, voltage scalability and readiness level and includes mechanical and hybrid (combination of mechanical and solid state switch es) concepts. Examples of test results from lab demonstrators and prototypes are shown, together with an outline of the main development needs.