ok---1-40207-28 多逆变器环境微网环流控制新方法.docVIP

多逆变器环境微网环流控制新方法 吕志鹏1 罗 安1 蒋雯倩2 徐欣慰1 （1. 湖南大学电气与信息工程学院 长沙 410082 2. 广西电网电力科学研究院 南宁 530023） 摘要 提出一种将模拟同步机运行的逆变器控制算法应用于多逆变器环境低压微网的环流控制新方法。低压微网由于微源容量较小、外特性差异大以及连接阻抗的特殊性，传统调频调压下垂控制算法在低压微网中不完全适用，不同微源间难以做到完全同步。对同步逆变器控制器下垂控制系数添加微分环节，有效改善因动态调节特性差带来的环流问题，并就两台下垂控制速度不同的2kW逆变器进行互联仿真和实验，在模式切换和负载突变情况下可有效抑制微网环流。 关键词：分布式发电 同步发电机 逆变器 微网 环流 中图分类号：TM464 New Circulation Control Method for Micro-Grid With Multi-Inverter Micro-Sources Lv Zhipeng1 Luo An1 Jiang Wenqian2 Xu Xinwei1 （1. Hunan University Changsha 410082 China2. Guangxi Electric Power Research Institute Nanning 530023 China） Abstract The new method of operating an inverter to imitate a synchronous generator for circulating current restraint is motivated and developed. As the capacity of micro-sources are small and there are differences on the external characteristics in the low-voltage micro-grid and the line impedance is unlike the large power grid, the conventional droop control is not fully applicable for the micro-grid. On the basis of the study on operating an inverter to mimic a synchronous generator, an improved droop controller is proposed by adding differential link to improve the dynamic performance. Using this idea, the real and reactive power delivered by the micro-source inverter connected in parallel and operated as generators can be automatically shared using the improved frequency and voltage drooping mechanisms rapidly. Both simulation and experiment has been done in a small-scale experimental micro-grid system which contains two prototypes of 2 kilowatt in parallel. The results are given to verify the circulation inhibitory is effective in a variety of conditions. keywords：Distributed generation，synchronous generator，inverter，micro-grid，circulation   1 引言 随着我国智能电网研究的深入，作为特高压电网的有效补充，包含多种能源形式和产出形式的微网得到了越来越多的关注[1-2]，微源并网逆变器接口的大量存在构成了多逆变器环境，微网内能源形式多样，使得电能质量问题的检测评估和分析控制更加复杂，由于多种微源外特性的差异和“不负责任”的无差调节特性微源的存在使得多逆变器环境下的微网微源间功率分配不均，输出波形难以做到同步，孤岛运行和负载突变的情况下更加严重。 功率/下垂控制是实现多机稳定并联的主要控制策略，移