引入新型虚拟阻抗的逆变器并联下垂控制策略
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摘要
针对孤岛运行的微电网中逆变器采用传统下垂控制并联时线路阻抗差异带来的功率分配不均以及输出阻抗带来的输出电压跌落过大的问题,提出了一种新型虚拟阻抗下垂控制方法。通过电压电流环控制参数设计输出阻抗为感性,实现有功功率和无功功率的解耦,满足传统下垂控制要求;无功-幅值下垂控制中引入由固定虚拟阻抗和可变虚拟阻抗两部分组成的新型虚拟阻抗,其中可变虚拟阻抗补偿功率不均分,固定虚拟阻抗补偿电压跌落。通过仿真与试验对比传统下垂控制与改进下垂控制,证明了提出的下垂控制方法能够提高并联系统无功功率均分度同时减小输出电压跌落。
Considering that when inverters are parallelled using the traditional droop method in the micro-grid,the difference between line impedance leads to the problem of unequal power distribution and the output impedance leads to the overmigration of output voltages,an improved droop method was proposed. The output impedance is designed to be inductive to meet droop control requirements. The power controller is redesigned and the point of common connection voltage and voltage regulation coefficient are introduced. The effect of line impedance on reactive power distribution and output voltage drop is reduced significantly. Comparing the traditional droop control and the improved droop control through the simulation and experiment,it is proved that the proposed droop control method can improve the reactive power average diversity of the parallel system and reduce the output voltage drop.
Considering that when inverters are parallelled using the traditional droop method in the micro-grid,the difference between line impedance leads to the problem of unequal power distribution and the output impedance leads to the overmigration of output voltages,an improved droop method was proposed. The output impedance is designed to be inductive to meet droop control requirements. The power controller is redesigned and the point of common connection voltage and voltage regulation coefficient are introduced. The effect of line impedance on reactive power distribution and output voltage drop is reduced significantly. Comparing the traditional droop control and the improved droop control through the simulation and experiment,it is proved that the proposed droop control method can improve the reactive power average diversity of the parallel system and reduce the output voltage drop.
引文
[1]周孝信,鲁宗相,刘应梅,等.中国未来电网的发展模式和关键技术[J].中国电机工程学报,2014,34(29):4999-5008.
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[8]王逸超,谢欣涛,陈仲伟,等.不同容量微网逆变器的自适应虚拟阻抗运行策略[J].电力自动化设备,2018,38(6):29-33.
[9]郭忠南,张纯江,孟晓脉,等.基于可变虚拟阻抗的接口逆变器改进下垂控制[J].电源学报,2014,12(6):66-72.
[10] MAHMOOD H,MICHAELSON D,JIANG J. Accurate reactive power sharing in an islanded micro-grid using adaptive virtual impedances[J]. IEEE Transactions on Power Electronics,2015,30(3):1605-1617.
[11] ZHU Y,FANG Z,WANG F,et al. A wireless reactive power sharing strategy for islanded microgrid based on feeder current sensing[J]. IEEE Transactions on Power Electronics,2014,30(12):6707-6719.
[12]闫俊丽,彭春华,陈臣.基于动态虚拟阻抗的低压微电网下垂控制策略[J].电力系统保护与控制,2015,43(21):1-6.
[13]张平,石健将,李荣贵,等.低压微网逆变器的“虚拟负阻抗”控制策略[J].中国电机工程学报,2014,34(12):1844-1852.
[14]陈燕东,罗安,龙际根,等.阻性逆变器并联环流分析及鲁棒下垂多环控制[J].中国电机工程学报,2013,33(18):18-29.
[15] ZHONG Q C. Robust droop controller for accurate proportional load sharing among inverters operated in parallel[J]. IEEE Transactions on Industrial Electronics,2013,60(4):1281-1290.
[16]全国电压电流等级和频率标准化技术委员会(TC1)和全国电磁兼容标准化技术委员会(TC246).电能质量供电电压偏差:GB/T 12325—2008[S].北京:中国标准出版社,2008.
[2]杨新法,苏剑,吕志鹏,等.微电网技术综述[J].中国电机工程学报,2014,34(1):57-70.
[3] GUERRERO J M,MATAS J,CASTILLA M. Wirelesscontrol strategy for parallel operation of distributed generation inverters[J]. IEEE Transactions on Industrial Electronics,2006,53(5):1461-1470.
[4]林燎源,林钊,刘伟,等.基于阻性下垂的逆变器无线并联均流控制[J].电工技术学报,2016,31(8):43-50.
[5] YAO W,CHEN M,MATAS J,et al. Design and analysis of the droop control method for parallel inverters considering the impact of the complex impedance on the power[J]. IEEE Transactions on Industrial Electronics,2011,58(2):576-588.
[6]吕志鹏,刘海涛,苏剑,等.可改善微网电压调整的容性等效输出阻抗逆变器[J].中国电机工程学报,2013,33(9):1-9.
[7]刘尧,林超,陈滔,等.基于自适应虚拟阻抗的交流微电网无功功率-电压控制策略[J].电力系统自动化,2017,41(5):16-21.
[8]王逸超,谢欣涛,陈仲伟,等.不同容量微网逆变器的自适应虚拟阻抗运行策略[J].电力自动化设备,2018,38(6):29-33.
[9]郭忠南,张纯江,孟晓脉,等.基于可变虚拟阻抗的接口逆变器改进下垂控制[J].电源学报,2014,12(6):66-72.
[10] MAHMOOD H,MICHAELSON D,JIANG J. Accurate reactive power sharing in an islanded micro-grid using adaptive virtual impedances[J]. IEEE Transactions on Power Electronics,2015,30(3):1605-1617.
[11] ZHU Y,FANG Z,WANG F,et al. A wireless reactive power sharing strategy for islanded microgrid based on feeder current sensing[J]. IEEE Transactions on Power Electronics,2014,30(12):6707-6719.
[12]闫俊丽,彭春华,陈臣.基于动态虚拟阻抗的低压微电网下垂控制策略[J].电力系统保护与控制,2015,43(21):1-6.
[13]张平,石健将,李荣贵,等.低压微网逆变器的“虚拟负阻抗”控制策略[J].中国电机工程学报,2014,34(12):1844-1852.
[14]陈燕东,罗安,龙际根,等.阻性逆变器并联环流分析及鲁棒下垂多环控制[J].中国电机工程学报,2013,33(18):18-29.
[15] ZHONG Q C. Robust droop controller for accurate proportional load sharing among inverters operated in parallel[J]. IEEE Transactions on Industrial Electronics,2013,60(4):1281-1290.
[16]全国电压电流等级和频率标准化技术委员会(TC1)和全国电磁兼容标准化技术委员会(TC246).电能质量供电电压偏差:GB/T 12325—2008[S].北京:中国标准出版社,2008.