孤岛微电网的电压不平衡二次控制策略  

Secondary control strategy for compensation of voltage unbalance in islanded power-microgrid

作　　者：吴丽珍[1] 杨旭生[1] 郝晓弘[1] 杨巧玲[1] 骆作颢 

机构地区：[1]兰州理工大学电气工程与信息工程学院,甘肃兰州730050

出　　处：《兰州理工大学学报》2016年第5期84-89,共6页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51467009);兰州市科技计划项目(2014-1-162)

摘　　要：为了解决微网公共耦合点(point of common coupling,PCC)电压不平衡问题,提出基于二次控制的电压不平衡补偿方法.该方法依据分层控制理论,建立二次控制层,通过二次控制层中的微电网中央控制器对每个分布式电源的本地控制器产生的偏差进行二次控制与调节,并采用低带宽通信网络实现控制层之间的信息交换.而本地控制层则采用改进的下垂控制方法,并加入虚拟阻抗环来控制逆变型微源的等效输出阻抗特性;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.该方法不仅从全局的角度补偿PCC点的电压偏差,而且实现无功功率的精确分配.最后仿真验证了所提控制策略的有效性.In order to solve the problem of voltage unbalance at point of common coupling （PCC） in mi- crogrid, a secondary control-based voltage unbalance compensation method is proposed. In this method, a secondary control layer is set up based on hierarchical control theory, the deviation produced by central eontroller of microgrid of the secondary control layer in every local controllers of distributive power is used to conduct secondary control and regulation, and the low-bandwidth communication network is employed to realize information exchange between the control layers. And in the local control layer, an improved droop control with virtual impedance loop is used to control the characteristics of equivalent output imped- ance and the proportional resonant control is used to implement static-deviation-free control of current and voltage in voltage-current loop. This method will not only compensate globally the deviation of PCC volt- age, but also implement precise reactive power sharing. Finally, it is verified by simulation that the pro- posed control strategy is valid.

关 键 词：微电网 分层控制 电压不平衡度 下垂控制 比例谐振控制 

分 类 号：TM76[电气工程—电力系统及自动化]