为了改善直流逆变站的无功功率特性,合理利用直流系统本身的无功调节特性来提升弱受端系统的电压稳定性,对直流控制方式与逆变器无功需求之间的关系进行了比较详细的分析。基于弱受端直流系统模型,首先根据直流系统Ud-Id特性曲线分析得到直流系统各种可能的控制模式下的无功特性,以及各控制模式对无功功率的调节能力;然后分析了熄弧角裕度、VDCOL参数、控制器调节速度这3种因素对逆变器无功调节的影响,并根据仿真结果总结了它们的调节规律及作用范围。对弱受端直流系统无功调节策略的确定具有一定的指导意义。
To improve the reactive power characteristics of inverter station, and voltage stability of the inverter weak AC system through utilizing the reactive power regulation characteristics of HVI)C system reasonably, it is necessary to analyze the relationship between HVDC control and inverter reactive power demand in detail. Based on a certain HVDC system model connected to a weak AC system in this paper, the reactive characteristics of each operating mode of the HVDC system varying with HVDC inverter AC bus voltage is obtained according to the HVDC Ud-Id characteristic curve, and then the regulation ability of each mode on reactive power is analyzed. Finally, the influence of extinction angle margin, VDCOL parameter, and regulation speed of status parameter on the regulating reactive power of inverter is also analyzed, and their regulation rules and scope according to the simulation results are summarized. The conclusion of the study has some significance in reactive regulation strategy for the weak-end HVDC system.