级联恒功率负载情况下三相并网PWM整流器基于TS模糊模型的稳定性分析  

Stability of Three-phase Grid-connected PWM Rectifier Cascaded With Constant Power Loads Based on TS Fuzzy Models

作　　者：聂金铜[1] 赵争鸣[1] 袁立强[1] 文武松 张颖超 NIE Jintong;ZHAO Zhengming;YUAN Liqiang;WEN Wusong;ZHANG Yingchao(State Key Lab of Control and Simulation of Power Systems and Generation Equipment(Dept.of Electrical Engineering,Tsinghua University),Haidian District,Beijing 100084,China;Communication Sergeants College,PLA Army Engineering University,Shapingba District,Chongqing 400035,China)

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系),北京市海淀区100084 [2]陆军工程大学通信士官学校,重庆市沙坪坝区400035

出　　处：《电网技术》2020年第5期1931-1940,共10页Power System Technology

基　　金：国家自然科学基金重大项目(51490683);国家自然科学基金面上项目(51577100)。

摘　　要：恒功率负载(constant power loads, CPL)的负阻抗特性是引起前端独立运行能够稳定的变换器带负载时却失去稳定的主要原因,由于电路状态方程的非线性,难以得到状态变量的时域解来判断系统稳定性。基于小信号线性化、以特征根的分布来评估系统稳定性的方法,需要在平衡点处线性化并以数值方法求解特征根,且无法描述出大信号扰动时的渐近稳定范围。针对并网型三电平整流器直接带恒功率负载和以LC滤波器连接恒功率负载的2种系统,使用Takagi-Sugeno(TS)模糊推理模型方法建立考虑主电路参数和控制器参数的全阶模型,以线性矩阵不等式(linear matrix inequality,LMI)的半正定规划是否能够求解作为系统稳定判据,从而能够分析系统参数与稳定区间之间的关系。同时构造的Lyapunov备选函数能够绘制出稳定吸引域(stability domain of attraction,DOA),实现大扰动情况下的稳定性分析。仿真和实验验证了该方法的有效性和实用性。The negative impedance characteristics of constant power loads(CPL) are the main reason of instability of the front-end converters which can work alone stably. Because of the nonlinearity of circuit state equations, it is relatively hard to derive the time domain expressions of the state variables to judge the stability of the system. The approaches based on small signal linearization and the distribution of eigenvalues require the linearization around the equilibrium point and the numerical solution of the eigenvalues. Besides, they are unable to obtain asymptotically stable region when encountering a large signal disturbance. In this work, Takagi-Sugeno(TS) fuzzy inference modeling methods are utilized to obtain the two full order models of the grid-connected three-level PWM rectifier which is connected with CPL directly or connected with CPL through LC filter respectively, taking both the main circuit model parameters and the controller parameters into consideration. Whether the semidefinite programming problem of the linear matrix inequality(LMI) is feasible is utilized to judge the system stability so as to analyze the relation between system parameters and the stability region. Meanwhile, the Lyapunov candidate function constructed can be used to plot the stability domain of attraction(DOA) and analyze the stability under a large disturbance. The simulation and experimental results validate the effectiveness of this stability criterion.

关 键 词：PWM整流器 稳定性分析 恒功率负载 TS模糊模型 线性矩阵不等式 

分 类 号：TM721[电气工程—电力系统及自动化]