HVDC受端换流站动态无功功率恢复特性及控制措施仿真

Simulation of Recovery Characteristics and Control Measures of Dynamic Reactive Power of HVDC Inverter Station

研究了受端交流系统发生大扰动的情形下,直流换流站动态无功功率的恢复特性及其调控措施。基于准稳态模型分析了换流器无功功率的影响因素,采用某实际直流的EMTDC模型展开仿真研究,阐述恢复期间换流器动态无功功率的共性特征并从控制系统和换流变压器的角度进行机理分析。指出通过优化VDCL控制参数和定熄弧角控制两种途径改善换流站动态无功功率恢复特性的特点和利弊。某实际交直流大电网中的EMTDC仿真结果校验了换流站动态无功功率的共性特征和控制策略的有效性。

The recovery characteristics of dynamic reactive power of DC inverter station and its regulation and control measures are in- vestigated when severe disturbances occur in the receiving-end of AC system. The influencing factors of converter reactive power are studied based on the quasi steady state model. By simulations with an HVDC EMTDC model corresponding to an actual project, the common characteristics of dynamic reactive power during the recovery period are elaborated, and the mechanism analysis is carried out from the aspects of control system and converter transformer. The features, advantages and disadvantages are compared between the VDCL control parameters optimization method and the extinction angle control optimization method for altering the inverter reactive power characteristics. EMTDC simulations results of a practical AC/DC power grid validate the common characteristics of dynamic re- active power of inverter stations and the effectiveness of control strategy.