Mixed-type high-voltage DC breaker and implementation method thereof

The invention discloses a mixed-type high-voltage DC breaker and an implementation method thereof. The DC breaker is connected in a DC system in series and concretely comprises the following branches connected in parallel: an on-state branch, a pre-transfer branch, a re-transfer branch and an energy-dissipating branch. The on-state branch comprises at least one quick mechanical switch and a first current transfer module including a full control device, and the quick mechanical switch and the first current transfer module are connected in series. The pre-transfer branch comprises the following parts connected in series: a first inductor, a first semi-control device thyristor serial connection module, and a second current transfer module including a full control device. The re-transfer branch comprises the following parts connected in series: a second inductor, a second semi-control device thyristor serial connection module, and a capacitor. The energy-dissipating branch is formed by a non-linear resistor. The implementation method comprises corresponding operations when the DC system runs normally or when a short circuit fault happens to the DC system. With the prerequisites including a fast enough breaking speed and low losses ensured, the DC breaker employs the semi-control device thyristors, so that the capability of breaking current is good, the voltage-withstanding level is high, and the cost is greatly reduced.