不平衡电网下新能源三相并网逆变器功率-电流协同控制研究  

Research on Power-current Cooperative Control of Three-phase Grid-connected Inverters for Renewable Energy under Unbalanced Grid Condition

作　　者：杨国良 高鹏涛 陈子文 YANG Guoliang;GAO Pengtao;CHEN Ziwen(Hebei key Laboratory of Power Electronics for Energy Conservation and Drive Control,Heibei Qinghuangdao 066004,China)

机构地区：[1]河北省电力电子节能与传动控制重点实验室,河北秦皇岛066004

出　　处：《电力电容器与无功补偿》2025年第2期73-81,共9页Power Capacitor & Reactive Power Compensation

基　　金：国家自然科学基金(61873226)。

摘　　要：近年来对于可再生能源的利用和分布式电源在电网系统中的比重日益上升,电力系统电力电子化的趋势越来越明显。随之而来的问题是当电网电压不平衡时并网逆变器系统性能降低,严重时需在电网中切除的问题,这将严重影响电力系统的稳定性,所以不平衡电网下的并网逆变器控制尤为关键。电网电压不平衡条件下系统的输出功率和电流质量是并网逆变器的主要关注指标。本文以三相三线制的LCL型并网逆变器为例,分析相位检测失准和功率波动问题,提出了一种改进的锁相环和功率-电流协同控制策略,该方法可以统一参考电流公式和协调系数,实现并网电流、有功功率和无功功率之间的平滑切换。通过Matlab/Simulink仿真和RT-LAB平台的实验,验证了所提策略的可行性与有效性。In recent years,the utilization of renewable energy and the proportion of distributed generation in power grid systems have been increased significantly,and the trend of power electronics in power systems is becoming more and more evident.The problem that arises is that when the grid voltage is unbalanced,the performance of grid-connected inverters decreases which shall be eliminated in the power grid,otherwise it can seriously affect the stability of the power system.Therefore,the control of grid-connected inverters under unbalanced grid conditions is particularly critical.The output power and current quality of the system under unbalanced grid voltage conditions are the main concerned data of grid-connected inverters.In this paper,a three-phase three-wire LCL-type grid-connected inverter is taken as an example,the issues of phase detection inaccuracies and power fluctuations are analyzed,and an improved phase-locked loop(PLL)and power-current cooperative control strategy is proposed.This method can refer to the reference current formula and coordination coefficients to achieve smooth switching among grid-connected current,active power,and reactive power.The feasibility and effectiveness of the proposed strategy are verified through Matlab/Simulink simulations and experiments on the RT-LAB platform.

关 键 词：不平衡电网 三相逆变器 功率-电流协调控制 改进锁相环 协调系数 

分 类 号：TM464[电气工程—电器]