±800kV/4750A特高压直流换流阀宽频建模及电压分布特性研究

Study on Wide-band Model and Voltage Distribution of 800 kV/4750 A UHVDC Valves

直流输电换流阀的电压分布性能是其重要电气特性之一。它不但影响换流阀的可靠性,甚至也影响阀的成本。而电压性能的计算不但与分析方法有关,也受电路模型精确度的影响。针对±800kV/4750A特高压换流阀建立宽频电路模型,试验和仿真结果表明所建的宽频模型是可行的,并具有较高的精确度。此外,也就电路元件参数和杂散电容对该特高压换流阀电压分布的影响进行分析,并总结其中的关键因素。结果表明对于阀的电压分布性能来说,饱和电抗器设计和阀层对地杂散电容尤为重要。

The voltage distribution performance of high voltage DC （HVDC） converter valve is one of important research contents about its electric characteristics. It influences the reliability even cost of converter valve. However, the calculation of voltage distribution performance is affected by analysis method and the circuit model of converter valve. In this paper, the wide-band model of ＋800 kV/4 750 A ultra HVDC （UHVDC） converter valve was built. The results of test and simulation indicate that the model is available. Further, both the influences of power circuit parameters and stray capacitances on the voltage distribution of such a converter valve were investigated and the key factors were also summarized. They indicate that for even voltage distribution, both the design of saturable reactor and the value of stray capacitances between valve layers and earth are important.