储能逆变器并网次同步谐振机理分析与抑制方法  

Mechanism Analysis and Suppression Method of Sub-synchronous Resonance for Energy Storage Inverter Connecting to Power Grid

作　　者：于鸿儒 苏建徽[1] 郑林 张涛[1] 张迪 施永 YU Hongru;SU Jianhui;ZHENG Lin;ZHANG Tao;ZHANG Di;SHI Yong(Research Center for Photovoltaic System Engineering of Ministry of Education(Hefei University of Technology),Hefei 230009,China;State Key Laboratory of Advanced Power Transmission Technology(Global Energy Interconnection Research Institute Co.,Ltd.),Beijing 102209,China)

机构地区：[1]光伏系统教育部工程研究中心(合肥工业大学),安徽省合肥市230009 [2]先进输电技术国家重点实验室(全球能源互联网研究院有限公司),北京市102209

出　　处：《电力系统自动化》2020年第23期99-108,共10页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51907045);安徽省自然科学基金资助项目(1908085QE238);全球能源互联网研究院有限公司自筹资金科技项目(5355ZS170002)的资助。

摘　　要：主感性网络下逆变器并网极易出现振荡问题。文中首先推导出了计及跨时间尺度交互作用的改进电磁模型,揭示了输出阻抗与线路阻抗的相互作用导致系统的功率环特性发生改变,甚至引发次同步谐振。基于此,提出了输出功率比例微分反馈策略,比例反馈利用系统高频衰减特性降低谐振增益,微分反馈削减谐振峰值,增益补偿用以维持系统带宽,并给出了各反馈系数的具体设计方法。输出功率比例微分反馈策略可在保持系统低频特性的同时,有效抑制次同步谐振,提高系统稳定性。最后,通过实验验证了改进电磁模型的正确性和输出功率比例微分反馈策略的有效性。The inverter connecting to a power gird in a mainly inductive network is prone to oscillation problems.This paper derives an improved electromagnetic model considering the cross-time-scale interaction.It is revealed that the interaction between the output impedance and the line impedance leads to the change of the power loop characteristics of the system,and even leads to sub-synchronous resonance(SSR).Based on this,a proportional differential feedback strategy of output power is proposed.The proportional feedback uses the high-frequency attenuation characteristics of the system to reduce the resonance gain.The differential feedback reduces the resonance peak.And the gain compensation is used to maintain the system bandwidth.The specific design methods of each feedback coefficient are given.The proportional and differential feedback strategy of output power can effectively suppress SSR while maintaining the low-frequency characteristics of the system,and improves the system stability.Finally,the correctness of the improved electromagnetic model and the effectiveness of the proportional and differential feedback strategy of output power are verified by experiments.

关 键 词：并网逆变器 同步谐振 次同步谐振 振荡抑制 改进电磁模型 时间常数 输出功率比例微分反馈 

分 类 号：TM464[电气工程—电器] TM712