电网不平衡工况虚拟同步发电机优化控制  

Optimal Control for Virtual Synchronous Generator Under Condition of Unbalanced Grid Voltage

作　　者：孙筠 SUN Jun(Hubei University of Education,Wuhan 430205,China)

机构地区：[1]湖北第二师范学院,物理与机电工程学院,湖北武汉430205

出　　处：《电力电子技术》2021年第5期45-48,共4页Power Electronics

基　　金：国网公司科技项目(5201011800N)。

摘　　要：虚拟同步发电机(VSG)以模拟机转子运动方程和调频/调压特性为控制内核,可在并/离网工况下实现单模式运行控制,在主动配电网和微电网领域应用前景良好。然而,当电网不平衡时,VSG需要同时兼顾对并网负序电流的抑制及离网独立运行的系统稳定性。在此分析了电网不平衡工况下,传统电压源VSG常规控制策略的局限性和系统离网独立运行时的不稳定机理,提出一种基于谐振滤波的VSG负序电流优化控制,实现了VSG在电网不平衡条件下的入网电流平衡输出。所提控制策略的有效性和可行性获得了仿真和实验验证。The virtual synchronous generator(VSG)takes the synchronous generator rotor motion equation and the frequency modulation/voltage regulation characteristics as the control core,and can realize single-mode operation control under on-grid and off-grid mode.However,when the grid is unbalanced,the VSG realizes the suppression of the negative sequence current and maintains the three-phase grid-connected current balance,on the other hand,guarantees the terminal voltage balance and system stability under off-grid operation mode.Aiming at this problem,the basic model and working principle are briefly analyzed firstly,the limitations of conventional positive and negative sequence separation control applied to VSG under unbalanced voltage are analyzed,and the mechanism of system instability is analyzed.Based on the single-mode operation control,a novel control strategy based on resonant filter is proposed.Simulation and experimental results verify the correctness and effectiveness of the proposed control strategy.

关 键 词：虚拟同步发电机 电网不平衡 控制策略 稳定性 

分 类 号：TM341[电气工程—电机]