含负荷功率自动分配的独立直流微电网协调控制  

Coordinated Control for Autonomous DC Microgrid With Dynamic Load Power Sharing

作　　者：米阳[1] 吴彦伟[1] 朱银珠[2] 符杨[1] 王成山[3] 

机构地区：[1]上海电力学院电气工程学院,上海市杨浦区200090 [2]国网安徽省电力公司蚌埠供电公司,安徽省蚌埠市233000 [3]天津大学电气与自动化工程学院,天津市南开区300072

出　　处：《电网技术》2017年第2期440-447,共8页Power System Technology

基　　金：国家自然科学基金资助项目(61403246);上海教委科研创新项目(15ZZ085);中国博士后科学基金研究项目(2014M560187);上海绿色能源并网工程技术研究中心项目资助(13DZ2251900)~~

摘　　要：针对独立运行直流微电网,提出了含负荷功率自动分配的协调控制策略。孤岛运行状态下,直流微电网需独自承担系统电压稳定,为此采用多组小容量储能单元平衡分布式电源(DG)和负荷功率从而控制母线电压稳定。同时,为了避免储能系统过充和过放以及降低对通讯的依赖程度,根据各储能单元的荷电状态(SOC)和最大功率设计自适应下垂控制自动协调不同储能单元之间的负荷功率分配,可减小电压波动。当储能系统充电功率超过其最大允许功率或满充时,不同DG单元根据各自最大输出功率由最大功率跟踪控制(MPPT)切换为带有电压前馈补偿的下垂控制模式稳定母线电压和自动分配负荷功率,并考虑各单元的输出阻抗来提高分配精度。最后利用Matlab/Simulink对所设计的控制策略在不同运行模式下进行仿真验证,仿真结果表明所提出的控制策略可协调不同模式下独立直流微电网稳定运行和实现负荷功率自动分配。Coordinated control strategy with dynamic load power sharing is proposed for island DC microgrid in the paper. The DC microgrid alone is responsible for voltage stability under island mode. Therefore, multi-groups of storage units are used to assure voltage stability through balancing power between distributed generations and loads. Besides, in order to avoid over-charge or deep-discharge of storage units and to reduce dependency on communication, adaptive droop controller is designed to dynamically allocate load power among storage units considering their charge states and maximum power to reduce voltage fluctuation. Distributed generations are switched from maximum power point tracking control to voltage feed forward compensated droop control to stabilize bus voltage when charge power of storage system exceeds its upper limit, thus load power is dynamically shared by distributed generations according to their maximum power. Their output impedance is considered to improve allocation accuracy. Finally, simulations under different operation modes are carried out in Matlab/Simulink. Results indicate that the proposed strategy may assure stable system operation and realize dynamic load power allocation.

关 键 词：直流微电网 下垂控制 自适应 负荷功率分配 

分 类 号：TM721[电气工程—电力系统及自动化]