【摘要】 传统的高压直流输电(HVDC)准稳态模型不能准确描述换流器开关电路的动态特性,故运用采样-数据建模方法建立了HVDC主电路在d-q参考坐标下的小信号线性化模型:每隔1/6工频周期对系统进行采样,并通过积分推导得出采样点之间的函数关系,对该函数进行线性化得到相应的小信号模型。与传统准稳态模型不同,该模型反映了换流器开关电路在工作点受到小扰动时的动态特性。通过时域仿真证明了该模型的准确性及其适用频率范围为0～3倍工频。将该模型用于次同步振荡(SSO)的特征值分析,并与传统的准稳态模型分析结果对比,证明HVDC准稳态模型适用于SSO分析。更多还原

【Abstract】 Conventional quasi-steady model of HVDC is not able to describe the dynamic switching behavior of HVDC converters. By means of the sampling-data modeling approach, a linear time-invariant (LTI) small-signal dynamic model is developed for HVDC main circuit in the synchronous rotating d-q reference frame: taking one sample per 1/6 cycle of fundamental frequency, deriving the function between the sampled points by integrating, and linearizing the function, then the small-signal model can be obtained. In contrast to conventionally used quasi-steady model, the developed model represents the dynamic response of converter switching circuit to nominal changes in operating point. The linearized model is validated by a set of time-domain simulation and the derived suitable frequency range is 0-3 times fundamental frequency. The model is applied in SSO analysis and the results are compared with those that utilize quasi-steády model. It is proved that the quasi-steady model of HVDC is valid for normal SSO analysis.更多还原