The Commutation Booster, a New Concept to Aid Commutation in Hybrid DC-Breakers

The difficulty in interrupting DC currents lies in the lack of a natural current zero crossing. In an ACbreaker, the current is interrupted by separating the contacts to draw an electric arc. When the current naturally goes to zero, the arc is extinguished and the current is interrupted. For DC, the current zero has to be forced by the breaker. Hybrid solutions with mechanical switches and power semiconductors have been proposed to combine low conduction losses with the ability to force a current zero.