电网技术2017，Vol.41Issue(11)：3573-3581,9.DOI:10.13335/j.1000-3673.pst.2016.3212
电网电压不平衡时的改进虚拟同步机控制策略
An Improved Control Strategy for Virtual Synchronous Generator Under Unbalanced Grid Voltage
摘要
Abstract
Under unbalanced grid voltage, traditional virtual synchronous generator (VSG) control strategy will result in unbalanced three-phase current and fluctuation in active and reactive power. In this paper, mathematical models are derived for instantaneous active and reactive power under unbalanced grid voltage, and an improved VSG control strategy is proposed to handle these problems in traditional VSG control strategy. Firstly, under dq coordinate system, VSG balance current control is employed to obtain reference positive-sequence current commands. Secondly, according to grid voltage unbalanced parameters, positive and negative sequence current commands of grid-connected inverter are produced for different control objectives. Thirdly, positive and negative sequence current commands are tracked separately to get positive and negative sequence voltage modulation signals. The proposed control strategy maintains original VSG control characteristics without changing VSG control mechanism, produces balanced three-phase current output and mitigates active or reactive power fluctuations separately. Simulation and experiment results verify effectiveness of the proposed control strategy.关键词
虚拟同步发电机/电网电压不平衡/电流不平衡/有功及无功功率波动/正、负序电流Key words
VSG/unbalanced grid voltage/unbalanced three-phase current/active and reactive power fluctuation/positive and negative sequence current分类
信息技术与安全科学引用本文复制引用
万晓凤,胡海林,聂晓艺,余运俊,曾繁鹏..电网电压不平衡时的改进虚拟同步机控制策略[J].电网技术,2017,41(11):3573-3581,9.基金项目
国家自然科学基金(61563034) （61563034）
国家国际科技合作专项(2014DFG72240) （2014DFG72240）
江西科技落地计划(KJLD14006). Project Supported by National Natural Science Foundation of China (61563034) （KJLD14006）
Program of China International Science and Technology Cooperation Projects (2014DFG72240) （2014DFG72240）
Higher School Science and Technology Floor Plan in Jiangxi Province (KJLD14006). （KJLD14006）
