特高压直流换流阀的运行性能及其失效机制

Study on Operating Performance and Failures Mechanism of UHVDC Thyristor Valves

直流换流阀是特高压直流输电工程的核心装置,为了保障换流阀的运行可靠性,满足其试验方法研究的需要,有必要研究换流阀的运行性能及其失效机制。首先分析了换流阀的各个运行工况,给出了不同运行工况的特点及Matlab/Simulink仿真波形。然后讨论了换流阀在不同工作周期(开通、通态、关断和断态)下的运行状态,建立了等效开通/关断模型,并结合器件的内部物理特性,分析阀失效情况的发展过程,最终揭示了其失效机制。

Thyristor valve is the core device of UHVDC transmission project. In order to ensure the operation reliability of valves and to meet the research needs of its test methods, it is necessary to study the operation performance and failures mechanism of UHVDC valves. In this paper, each of the operation conditions of valves is analyzed, and the characteristics of different operation conditions and the simulation waveforms are illustrated. Then the operation status of valves in different duty cycles （turn-on, on-state, turn-off and off-state） is discussed and the equivalent turn-on/off model is established. Finally, combined with the internal physical characteristics of the device, the development process of the valve failure is analyzed and the failure mechanism is demonstrated.