摘要
随着微网规模的日益扩大,微网中负载的不对称,导致了微网电压出现不平衡。为此提出了在αβ坐标系下的低压微网电压不平衡补偿方法。该方法包括改进的下垂控制,可使微源逆变器根据本地配置的实际情况改善功率分配;电压不平衡补偿环节,协调控制分布式发电单元的有功和无功功率以自动补偿微电网电压不平衡;并加入虚拟阻抗环来灵活地控制逆变型微源的等效输出阻抗特性;而电压电流环则采用准比例谐振控制实现电流、电压的无静差控制。最后通过仿真结果证明了所提控制策略的有效性。
Along with expansion of micro-grid scale,load unbalance in the micro-grid leads to voltage unbalance in the micro-grid. This paper presents a method for compensating voltage unbalance of the low-voltage micro-grid in the case of the αβ coordinate system. This method includes an improved droop control for enabling the micro-source inverter to improve its power distribution according to actual local configuration,as well as a voltage unbalance compensation component for coordinating active and reactive powers of the distributed generators（ DG） in their automatic compensation of voltage unbalance in the micro-grid. Furthermore, a virtual impedance loop is added for flexible control of the equivalent output impedance of the inverse micro-source. In the voltage-current loop,quasi-proportional-resonant control is adopted to realize a floating control over voltage and current. Finally,simulation results verify the effectiveness of the proposed control strategy.
出处
《电气自动化》
2016年第2期72-75,共4页
Electrical Automation
基金
国家自然科学基金项目(No.51467009)
兰州市科技计划项目(No.2014-1-162)
国网科技计划项目(14-JS-188)
关键词
微电网
电压不平衡度
下垂控制
准比例谐振控制
虚拟阻抗环
micro-grid
voltage unbalance degree
droop control
quasi-proportional resonant control
virtual impedance loop
