虚拟阻抗制动可再生能源机组低电压穿越控制  

Low voltage ride-through control of a renewable energy unit with virtual impedance braking

作　　者：高长伟[1] 黄翀阳 郑伟强 王伟 朱宁 GAO Changwei;HUANG Chongyang;ZHENG Weiqiang;WANG Wei;ZHU Ning(College of Electrical and Automation Engineering,Liaoning Institute of Science and Technology,Benxi 117004,China;School of Electrical Engineering,Shenyang University of Technology,Shenyang 110870,China;Yingkou Power Supply Company,Yingkou 115002,China;College of Continuing Education,Liaoning Institute of Scince and Technology,Benxi 117004,China)

机构地区：[1]辽宁科技学院电气与自动化工程学院,辽宁本溪117004 [2]沈阳工业大学电气工程学院,辽宁沈阳110870 [3]辽宁营口供电公司,辽宁营口115002 [4]辽宁科技学院继续教育学院,辽宁本溪117004

出　　处：《电力系统保护与控制》2023年第10期142-152,共11页Power System Protection and Control

基　　金：辽宁省教育厅科学技术研究项目资助(LJKMR 20221698);辽宁科技学院博士科研基金项目资助(2107B01)。

摘　　要：电网电压跌落容易使可再生能源机组并网逆变器产生功角失稳与过电流现象,对系统安全稳定运行产生不利影响。对传统虚拟同步发电机(virtual synchronous generators,VSG)控制策略进行改进,提出了一种虚拟阻抗制动可再生能源机组低电压穿越控制策略。首先,利用等面积定则分析了电网电压跌落和恢复后VSG功角变化机理。其次,详细阐述了虚拟阻抗的无功干预机制与限流原理。然后,提出在电网电压跌落期间对传统VSG功率控制环节实施悬停控制以利于实现功角稳定,并对电压跌落与恢复的不同阶段限制过流所需虚拟阻抗值提出了明确计算方法。最后,利用RT-LAB实时仿真实验平台搭建了10 kW可再生能源并网机组,对不同电压跌落程度下的低电压穿越控制效果进行分析,验证了所提控制策略的可行性与有效性。Power grid voltage sag can easily cause power angle instability and an overcurrent phenomenon on a grid-connected inverter of a renewable energy unit.This paper improves the traditional virtual synchronous generator(VSG)control strategy.A low voltage ride-through(LVRT)control strategy for a renewable energy unit with virtual impedance braking is proposed.First,the principle of equal area is used to analyze the change mechanism of a VSG power angle after voltage sag and restoration.Second,a reactive power intervention mechanism and the current limiting principle of virtual impedance are described in detail.Then,it is proposed to implement hover control on a traditional VSG power control link during grid voltage sag in order to achieve power angle stability.A clear calculation method is proposed to limit the overcurrent at different stages of voltage sag and recovery.Finally,the RT-LAB real-time simulation experiment platform is used to build a 10 kW renewable energy grid-connected unit.The low voltage ride-through control effect at different voltage sag levels is analyzed,and the feasibility and effectiveness of the proposed control strategy is verified.

关 键 词：可再生能源 虚拟同步发电机 低电压穿越 虚拟阻抗 

分 类 号：TM341[电气工程—电机] TP273[自动化与计算机技术—检测技术与自动化装置]