基于全控型电力电子器件的强制换流型混合直流断路器

Hybrid DC Circuit Breaker with Forced Current Commutation Based on Full-controllable Power Electronic Devices

基于全控型电力电子器件的强制换流型混合直流断路器,在辅助换流电路分断过程中,缓冲电容放电会影响机械开关分断时间;当主断路器完成分断动作,线路能量仅仅依靠避雷器释放,避雷器投入费用较高,能量释放过程较慢,容易造成器件损坏,并影响避雷器使用寿命。提出一种强制换流型混合直流断路器方案,分析了该断路器工作原理,通过对比仿真验证了该方案的可行性。与传统基于全控型器件的强制换流型混合断路器相比,其在实现电流双向流动的同时全控型器件减半;阻止了缓冲电容放电对机械开关动作时间的影响;引入接地引流二极管,可使线路电流尽快减少到零。

In the hybrid direct current（DC）circuit breaker with forced current commutation based on full-controllable power electronic devices,the snubber capacitor discharge will affect the mechanical switch opening time in the process of auxiliary commutation circuit opening.When the action of the main circuit breaker is finished,the release of line energy just relies on the lightning arrester making the device damage-prone and affecting its useful life.The arrester investment cost is high and the time of energy dissipating is long.A hybrid DC circuit breaker with forced current commutation is proposed,and its operating principle is analyzed.Finally,the feasibility of this scheme is verified by comparing with typical hybrid DC circuit breakers.Compared with the traditional hybrid DC circuit breaker with forced current commutation based on full-controllable power electronic devices,the proposed scheme realizes the current bidirectional flow with only half the full-controllable power electronics devices.It can block the snubber capacitor discharging road without affecting the mechanical switch opening time,and reduce the line current to zero as soon as possible with a grounding diode circuit.