基于高频模型的换流阀换相过冲研究与阻尼回路参数优化

Study on Commutation Overshoot and Snubber Circuit Parameters Optimization of LCC Valve Based on High Frequency Model

为了抑制晶闸管换流阀在关断过程中产生的换相过冲电压,晶闸管两端需要安装阻尼电路。阻尼回路参数优化是换流阀设计的重要环节,其参数取值需要协调换流阀关断暂态的各项电气性能,确保换流阀安全可靠运行。首先建立了换流阀换相过冲电压计算电路,并对换流站设备高频参数对换流阀电压的影响进行详细分析。然后,对阻尼回路参数设计中所需要考虑的各项电气性能指标进行了详细讨论,并总结了阻尼回路参数对这些指标的影响。最后,提出可结合电磁暂态数值计算和非线性单纯形法对阻尼回路参数进行优化,并通过实例对该方法的可靠性和灵活性进行说明。

In order to limit commutation overshoots produced during the turn-off processes of LCC valves,it is necessary to install damping circuits parallel to thyristors.Parameter optimization of the damping circuit is an important part of valve design and the selected parameters should coordinate the turn-off electrical performance of the converter for its safe and reliable operation.Firstly,the calculation circuit of commutation overshoot is established,and the effects of high frequency parameters of related equipment on the valve voltage are analyzed.Then,the electrical performances that need to be considered in parameter design of the damping circuit are discussed in detail,and the influences of damping circuit parameters on the electrical performances are summarized.Finally,a method for optimizing parameters of the damper circuit is put forward by combining electromagnetic transient numerical calculation with nonlinear simplex method,and the reliability and flexibility of the method are verified by examples.