高压微网运行模式切换控制策略  

Control Strategies of High-Voltage Microgrid for Operation Modes Switching

作　　者：张明锐[1] 杜志超[1] 王少波 孙华[3] 

机构地区：[1]同济大学电子与信息工程学院,上海201804 [2]上海环保工程成套有限公司,上海200070 [3]上海电气集团股份有限公司中央研究院,上海200070

出　　处：《电工技术学报》2014年第2期153-162,共10页Transactions of China Electrotechnical Society

基　　金：上海市自然科学基金(13ZR1444400);上海市科委重大专项(13DZ1200403);中央高校基本科研业务费专项资金(0800219169)资助项目

摘　　要：以未来可再生电能传输和管理(FREEDM)网络为研究对象,提出一种新型电压模式控制策略,用于实现FREEDM网络联网与孤岛模式间的切换。由于始终将并网逆变器控制为电压源,因此避免了运行模式变化时控制策略的切换,并采用改进的相角下垂控制取代传统频率下垂控制,使微网频率与输出功率分离,降低切换难度。联网运行时,将功率偏差作为反馈量加入到下垂控制环节,实现逆变器的恒功率输出。重新设计同步调节器,使微网进入联网模式时准同期并网,进入孤岛模式时降低脱网过程对微网的冲击,实现平滑过渡。仿真分析表明,本文所提出的控制策略可实现快速同步调节,切换过程公共连接点处(PCC)冲击电流较小,可以很好地稳定微网电压和频率,并有效抑制微网电源间环流。This paper puts forward a novel voltage mode control strategy to realize the smooth transition between the grid-connected and islanded operation mode of future renewable electric energy delivery and management（FREEDM）. Because the inverters are controlled to work as voltage sources all the time, the switch of control strategy is avoided. And the improved angle droop control strategy is used instead of conventional frequency droop control to set frequency free from the change of output , which reduces the difficulty of mode transition. The power deviation is added to the droop control block at the grid-connected mode to realize the constant output power control. The synchronization is ensured by employing the redesigned controller, and the integrator is utilized to reduce the impact when separated from conventional grid, thus the smooth transition of operation modes is achieved. Simulation and analysis show the proposed control strategy can realize fast synchronization, reduce the impact current of point of common coupling（PCC） during the mode transition period, steady the voltage and frequency of the microgrid, and also inhibit circulating current effectively.

关 键 词：微网 电压模式控制 虚拟阻抗 平滑切换 

分 类 号：TM732[电气工程—电力系统及自动化]