A Review of Voltage-Clamping Methods for Solid-State Circuit Breakers

In recent years, the interest in DC systems has increased dramatically because of some key advantages, in terms of efficiency and reliability, that this technology can offer compared to AC systems in applications such as shipboard distribution, more electric aircrafts, DC microgrids, battery protection, and photovoltaics. In this context, DC circuit breakers based on power semiconductors, the so-called solid-state circuit breakers, are becoming a popular choice because of their fast intervention speed, which is typically on the order of microseconds. Unfortunately, power electronics are vulnerable to "breakdown", which is a dangerous operating condition triggered by overvoltages. During current interruption, the energy stored in the inductive elements of the system must be dissipated, and this typically creates a very high voltage spike on the interrupting component, which is the breaker pole. This phenomenon, if not controlled, could lead to the premature failure of the semiconductor inside the solid-state circuit breaker. For this reason, suitable techniques aimed to control the voltage gradient and overshoot during interruption have been presented in the literature. This paper analyzes and compares the performances of the voltage-clamping solutions presented in the technical literature, which range from simple passive devices to more advanced solutions.