电工技术学报2025，Vol.40Issue(9)：2864-2879,16.DOI:10.19595/j.cnki.1000-6753.tces.240723
交直流混联系统的统一导阻网络建模及其稳定性分析
Modeling and Stability Analysis of Unified Immittance Network for AC/DC Hybrid System
摘要
Abstract
AC/DC hybrid system has become an effective solution for large-scale new energy consumption because of its characteristics of multiple power sources,multiple drop points,large capacity and cross-regional flexible transmission.However,the wide-frequency oscillation problem of AC/DC hybrid power system with high proportion of power electronics is prominent,which threatens the safe and stable operation of the system.At present,the stability analysis of hybrid system is mainly faced with the problem of how to take into account the AC and DC sections of the hybrid system at the same time and how to cover the system equipment with different impedance characteristics,so as to realize the unified analysis of the AC/DC hybrid network with multiple power electronic equipment.To address the above issues,this paper establishes a unified immittance network model for system-level stability assessment of hybrid systems. First,based on the voltage/current source type device characteristics of the network devices,the impedance/admittance forms of each network module of the system are standardized to avoid the problem of solving for the right half-plane poles in the process of system stability analysis.Secondly,from the perspective of the AC and DC ports of the system equipment,the AC/DC hybrid system can be divided into mono immittance subsystem and hybrid immittance subsystem.Finally,based on the interaction relationship between system immittance networks,a unified immittance network model containing complete oscillation information of the hybrid system is established.Under the premise of covering the stability information at each AC and DC port of the hybrid system,the unified immittance network model reduces the dimension of the system network model,at the same time expands the system network matrix from a single AC or DC system to an AC/DC system.Furthermore,combined with the derivation and change process of the immittance network,and through the modularization of the system expansion,this paper makes the immittance network applicable to the analysis of objects with different topologies,and extends the unified immittance network to general AC/DC hybrid systems.In addition,in contrast to the matrix model that merely aggregates a single impedance feature or a single admittance feature,the unified immittance network encompasses the AC/DC systems with various impedance characteristics,accomplishing the mutual unification of the new energy unit with admittance properties and the load network with impedance properties.This facilitates the precise establishment of the network mathematical model when confronted with the AC/DC system that concurrently incorporates equipment with current/voltage source characteristics,and realizes the unified coverage of equipment models with dissimilar impedance characteristics. Based on the immittance network model,a unified immittance network stability criterion covering the interaction relationship of each AC/DC port of the hybrid system is derived.Combined with the expansion analysis of the immittance network,the criterion is extended to the general AC/DC hybrid system.The stability criterion comprehensively covers the stability problems of the AC/DC system,and avoids solving the problem of poles in the right half-plane,simplifying the analysis process.Furthermore,an oscillation traceability method for the hybrid system is given based on the immittance network model.Finally,based on the application examples of the AC/DC hybrid system,the immittance network model and its stability analysis method proposed in this paper are evaluated and verified.关键词
交直流混联/导阻/稳定性分析/振荡溯源Key words
AC/DC hybrid/immittance/stability analysis/oscillation traceability分类
动力与电气工程引用本文复制引用
滕志远,陈新,张东辉..交直流混联系统的统一导阻网络建模及其稳定性分析[J].电工技术学报,2025,40(9):2864-2879,16.基金项目
国家自然科学基金资助项目(52277186). （52277186）
