微网功频振荡分析及阻尼联合控制策略  

Analysis of microgrid power frequency oscillation and damping joint control strategy

作　　者：王浩宇 蒋雯彬 杨林峰[1,2] 孔繁镍 WANG Haoyu;JIANG Wenbin;YANG Linfeng;KONG Fannie(School of Electrical Engineering,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Multimedia Communication and Network Technology,Nanning 530004,China)

机构地区：[1]广西大学电气工程学院,广西南宁530004 [2]广西多媒体通信与网络技术重点实验室,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2024年第4期773-787,共15页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金项目(72361003);广西自然科学基金项目(2021GXNSFAA220136)。

摘　　要：针对微电网多虚拟同步发电机(n-VSGs)并联运行时存在功率和频率振荡的问题,提出一种暂态自阻尼和互阻尼联合控制策略。本文首先对单VSG数学模型进行研究,推导出低阻尼比是造成自振荡主要因素;其次对双VSG数学模型进行研究,推导出互振荡环流功率是产生互振荡主要因素;提出自阻尼控制策略,增加暂态情况下的等效阻尼,弥补了由下垂系数和阻尼系数耦合问题导致的系统欠阻尼;提出互阻尼控制策略,利用虚拟阻抗特性,减小多机功频振荡实现互阻尼;最后提出阻尼联合控制策略,通过设计功率前馈提高系统自阻尼,设计频率前馈调整系统互阻尼,不影响稳态功率分配同时,实现多VSG频率功率联合控制。在MATLAB/Simulink中构建4VSG仿真模型,对所提出的控制策略进行验证,与传统下垂VSG控制相比较,阻尼联合控制策略能够协同抑制系统功频振荡,在保证系统功频稳定的同时改善了功频暂态性能指标,频率暂态时间从3.5 s缩减至0.7 s,功率超调量从11.11%抑制到3.70%。To address the problem of power and frequency oscillation during parallel operation of multiple virtual synchronous generators(n-VSGs)in microgrids,a combined transient self-damping and mutual damping control strategy is proposed.In this paper,firstly,the single VSG mathematical model is investigated,and it is deduced that the low damping ratio is the main factor of self-oscillation;secondly,the dual VSG mathematical model is investigated,and it is deduced that the inter-oscillatory circulating power is the main factor of the inter-oscillation;the self-damping control strategy is proposed to increase the equivalent damping in the transient case,and to make up for the under-damping in the system due to the coupling of the sag coefficients and damping coefficients;and the mutual-damping control strategy is proposed to utilize the virtual impedance characteristics to reduce the multi-machine power frequency oscillation to achieve mutual damping;finally,the damping joint control strategy is proposed to improve the system self-damping through the design of power feed-forward,and frequency feed-forward is designed to adjust the mutual damping of the system,the joint control of the multi-VSG frequency-power is realized without affecting the steady state power allocation at the same time.The proposed control strategy is verified by constructing a 4VSG simulation model in MATLAB/Simulink.Compared with the traditional sagging VSG control,the damping joint control strategy is able to suppress the system power frequency oscillation in a cooperative manner,and shorten the power-frequency transient performance indexes while guaranteeing the stability of the system power-frequency,with the frequency transient time reduced from 3.5 s to 0.7 s,and power overshooting amount suppressed from 11.11%to 3.70%.

关 键 词：多虚拟同步发电机 功频振荡 自阻尼控制 互阻尼控制 阻尼联合控制 

分 类 号：TM71[电气工程—电力系统及自动化] TM73