中文摘要：

基于电压源换流器（VSC）和脉宽调制（PWM）技术的新型高压直流输电（VSC-HVDC）,具有快速、灵活的有功功率和无功功率控制能力,能够改善系统的稳定性.文中建立了VSC-HVDC的小信号动态模型,该模型包括VSC与交流系统接口的线性化方程、VSC-HVDC内部直流系统动态过程的线性化方程以及控制系统线性化方程3个部分,具有一般性.以VSC的有功功率整定值为输入,VSC-HVDC并联交流输电线路的有功功率为输出,通过对系统频率响应的辨识,得到了两者间的开环传递函数.在此基础上,利用极点配置技术,设计了单输入单输出结构的VSC-HVDC附加阻尼控制器.对一VSC-HVDC/AC交直流并联输电系统特征根的分析及非线性仿真表明,配备该阻尼控制器的VSC-HVDC能有效地抑制系统低频振荡,增加系统阻尼.

英文摘要：

Voltage source converter （VSC） based HVDC （VSC-HVDC） is a new transmission technology which can improve the power system stability with its fast and independent capability to control the active and reactive power. The small signal dynamic model of VSC-HVDC is established in this paper. This model is general for including three parts, i.e. the small signal model for VSC, for VSC-HVDC inner dc system and for control system of VSC-HVDC. Taking the VSC＇s active power reference as input signal and active power of VSC-HVDC parallel ac line as output signal and using the system identification method, the opened-loop transfer function between the two signal is got from their frequency response. Based on the opened-loop transfer function, VSC-HVDC damping controller is designed in terms of pole assignment technology. Eigenvalue analysis and nonlinear simulation for a VSC-HVDC/AC parallel system verify that VSC-HVDC equipped with the designed damping controller can suppress the low frequency oscillation effectively.