基于确定-随机子空间的电力系统外部系统暂态等值

CDSI-Based Transient Equivalence of a Power System with External Systems

交直流混合输电技术的迅猛发展和电力电子设备在电力系统中普遍使用,使电力系统电磁暂态仿真分析及研究的必要性越来越高。但是,对实际大电力系统进行整体的电磁暂态仿真建模复杂且耗时很长。针对此问题,提出了基于确定-随机子空间的电力系统外部系统暂态等值新方法。首先,基于外部系统输入和输出数据,采用确定-随机子空间方法建立确定的激励-系统-响应模型,准确求解系统的状态空间表达式。然后,将外部系统端口状态空间表达式,转化成导纳有理函数式,根据零极点构建RLCG等值电路,进行建模等效简化,在宽频段范围内实现了对外部系统的暂态等值构建。最后,通过仿真和实测数据证明了文章所提方法有效缩短了仿真耗时,加快了仿真进程。

With the rapid advancements in AC-DC hybrid transmission technology and the growing prevalence of power electronic equipment in power systems,there is an escalating need to analyze and study the electromagnetic transient simulation of these systems.However,modeling the electromagnetic transients in actual large power systems proves to be both complex and time-consuming.To address this issue,a novel approach based on combined deterministic-stochastic identification is proposed for external system transient equivalence in power systems.Initially,a deterministic excitation system response model is established using input and output data from the external system.This model is developed via a deterministic random subspace method,allowing for accurate resolution of the state-space expression of the system.Subsequently,this state-space expression for the external system is converted into an admittance rational function expression.An RLCG equivalent circuit is then constructed based on the zero-pole locations,simplifying the modeling process and enabling the construction of a transient equivalent for the external system across a wide frequency band.In the final stage,simulation and measured data are employed to validate the proposed method.The findings demonstrate that this new approach can significantly reduce simulation time and accelerate the overall simulation process.