直流换相失败原因及对策研究

Study on the Reasons and Countermeasures of DC Commutation Failure

换相失败是高压直流输电系统中的常见故障,其威胁着交直流混联电网的安全稳定运行。本研究对某换流站自建站以来发生的换相失败情况进行统计分析,总结归纳换相失败的主要原因,并运用换相面积理论来分析不同因素对换相失败的影响机理。基于统计分析结果,从降低换相失败的概率出发,提出加强交流系统支撑、优化并联电容器组投入方式、优化直流控制参数等措施。经过对比分析,采取并联电容器组投入、优化直流控制参数的优化措施,易于实施,且效果良好,具有很好的工程应用前景。

Commutation failure is a common fault in HVDC transmission system,which threatens the safe and stable operation of AC/DC hybrid power grid. This study makes a statistical analysis of the commutation failure of a converter station since its establishment,summarizes the main causes of commutation failure,and uses the commutation area theory to analyze the influence mechanism of different factors on commutation failure. Based on the statistical analysis results,starting from reducing the probability of commutation failure,measures such as strengthening AC system support,optimizing the input mode of shunt capacitor banks,and optimizing DC control parameters are proposed. Through comparative analysis,the optimization measures of parallel capacitor bank input and DC control parameter optimization are adopted,which are easy to implement and have good effect,and have good engineering application prospects.