安装动态无功补偿装置有利于提高受端系统的电压稳定性． 文中提出了一种大扰动后逆变器动态无功需求峰值快速近似计算方法，用于确定动态无功补偿装置容量． 通
过对直流控制系统的深入分析，确定故障恢复过程中的直流控制方式并保留起主要作用的直流控制环节; 明确决定逆变器动态无功需求曲线的要素并分析其受故障程度的影响，阐明不同程度扰动下逆变器动态无功需求峰值相对固定的机理; 忽略扰动程度的影响，对系统参数作适当处理，用一条峰值最大的动态无功需求曲线近似估算不同程度扰动后的动态无功需求曲线; 对上述简化直流系统列写微分方程，求解出动态无功需求峰值; 利用该估算值确定受端系统应该加装的动态无功补偿装置容量． 楚穗直流PSCAD/EMTDC 模型的仿真结果验证了逆变器动态无功需求峰值估算值的准确性和文中动态无功补偿装置容量设计方法的可行性．

Dynamic reactive power compensation devices are effective in improving the voltage stability of the receiving end.In this paper,a fast proximate calculation method of dynamic reactive power peak demand in inverter after large disturbances is proposed to determine the capacity of dynamic reactive power compensation devices.In the investigation,first,the direct-current control mode is determined and the control links that play a major role in HVDC ( High-Voltage Direct Current Transmission) during the failure recovery are retained after a detailed analysis of HVDC control system.Next,the elements that determine the dynamic reactive power characteristics of the inverter are defined and the impact of disturbance severity on the elements is analyzed,which helps to clarify the mechanism by which the peak value of dynamic reactive power consumption of the inverter is relatively fixed.Then,some system parameters are properly processed without considering the impact of disturbance severity to estimate the dynamic reactive power characteristics after different AC voltage drops with a unique peak curve.Moreover,the differential equitation describing the simplified HVDC system is presented and the dynamic reactive power peak demand is obtained.Finally,the estimated demand value is used to determine the capacity of the dynamic reactive power compensation device installed in the receiving power network.Simulated results on Chu-Sui HVDC PSCAD/ EMTDC model show that the estimated dynamic reactive power peak is correct,and that the proposed design method of dynamic reactive poser compensation devices is feasible.