机械式高压直流断路器开断性能试验研究

Experiment Research on Breaking Capability of Mechanical Type HVDC Circuit Breaker

高压直流断路器是多端直流输电及高压直流系统联网的基础和安全保障,它不仅要能够开断短路电流而且要能够开断小负载电流,实现对高压直流系统的保护及控制功能。文中在振荡回路中对机械式高压直流断路器开断大电流及小电流的性能进行了测试。分别测试机械式高压直流断路器开断17.5 kA和开断50 A电流时的恢复电压值和恢复电压变化率。在试验中发现机械式高压直流断路器开断17.5 kA电流时可以在叠加高频振荡电流后的第1次过零点处开断,但是在开断50 A电流时需要在第2次电流过零点处才能开断。开断50 A电流时机械断路器上的恢复电压及恢复电压变化率均比开断17.5 kA电流时相应的值大。这一测试结果有助于全面了解高压直流断路器的性能。

High voltage DC circuit breaker(HVDC)is the foundation and security guarantee of the interconnection of HVDC and HVDC systems.It can not only break short circuit current but also break small load current,so as to real-ize the protection and control of HVDC system.In this paper,the performance of mechanical high voltage direct cur-rent circuit breaker breaking large current and small current in oscillation circuit is tested.The recovery voltage and the recovery voltage change rate of the mechanical HVDC circuit breaker were respectively tested when the 17.5 kA and 50 A currents were cut off.In the experiment,it is found that the mechanical HVDC circuit breaker can break off at the first zero point when the high frequency oscillating current is superimposed when the 17.5 kA current is bro-ken,but it needs to be broken at the second current zero point when the 50 A current is broken.When the 50 A cur-rent is switched off,the recovery voltage and the recovery voltage change rate of the mechanical circuit breaker are larger than the corresponding value when breaking the 17.5 kA current.The test results will help us to understand the performance of HVDC circuit breakers in a comprehensive way.