直流逆变端扰动对整流端影响机制及应对措施

Study on the Mechanism and Countermeasures of the Influence of Disturbance at Inverter Side on the Rectifier Side

特高压直流大容量送电使交直流相互作用程度加剧,直流传播逆变端交流电网扰动及其对整流端电网的影响,已不容忽视。该文首先建立了直流异步联网测试系统;研究了逆变端交流电压慢速起伏波动,以及快速跌落与恢复两种动态过程中,换流器触发角以及直流电流的暂态响应轨迹,揭示了直流传播逆变端扰动的机制;研究了整流站受扰功率响应特性,以及交流电网强度、直流控制参数等因素对其影响。在此基础上,针对哈密—郑州?800 kV/8 000 MW特高压直流输电工程中,逆变端故障引发整流端过电压冲击威胁,提出了加强电网结构和优化网源稳态无功配置的缓解措施,仿真结果验证了措施的有效性。

Due to the increasing high voltage direct current（HVDC） transmission capacity, the interaction degree between ac system and HVDC had aggravated, the mutual influence between the sending and receiving end of HVDC cannot be ignored. The asynchronous interconnected ac system by HVDC was established firstly. The dynamic response trajectory of converter firing angle and dc current was studied during the ac voltage at receiving end changing at different rate and the mechanism of disturbance propagation by HVDC was revealed. During the disturbed process, the transient power response characteristic of rectifier station was revealed, and the influence factors such as the strength of ac system, the setting value of controllers and so on were considered. On this basis, aiming to the overvoltage threaten occurred during Hami-Zhengzhou UHVDC receiving end fault, the mitigation measures that reinforcing ac network or optimizing the steady-state reactive power configuration are proposed, and simulation results verify the validity.