基于协调控制SVG的低压配网三相负荷不平衡治理技术
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摘要
针对集中式静止无功发生器(SVG)补偿系统补偿效果单一、不含通信功能的分布式SVG补偿系统补偿容量不能智能分配的问题,提出基于协调控制SVG的低压配网三相负荷不平衡补偿系统。该补偿系统引入通信总线,采用协调控制方法,使低压线路下游接入的SVG可利用补偿其下游不平衡电流后的剩余容量,依次对上游SVG不足容量进行补偿,该补偿形成的逆向潮流可进一步减轻各节点的低电压问题。该补偿系统既可以充分利用各SVG的补偿容量,同时也综合地解决了配电变压器电流不平衡、节点低电压等问题。在Matlab/Simulink数字仿真软件下进行了该补偿系统补偿效果的仿真,结果证明了该补偿系统的准确性。在四种不同负荷情况下比较采用四种不同补偿系统的低压配网配电变压器二次侧不平衡电流和各节点电压降,结果表明该补偿系统的效果最佳。
Concentralized static var generator(SVG) compensation system has single compen-sation effect and distributed SVG compensation system without communication function can not distribute SVG's compensation capacities intelligently. Aiming at these problems, a compensation system based on SVGs' coordinated control strategy was proposed for three-phase unbalance load in low voltage distribution network. Communication bus and coordinated control strategy are introduced in the proposed system. After compensating the downstream unbalance current, the residual capacity of the downstream SVG is used to compensate the upstream SVGs in sequence. The low voltage problem of each node is further reduced by the reverse power flows from the downstream SVG to the upstream SVG. And then SVG's capacity in the proposed compensation system can be fully used. Meanwhile, the problems of the distribution transformer's unbalance current and the node's low voltage are synthetically solved. Simulations for actual effect evaluation of the proposed compensation system were done in Matlab/Simulink. Validity of the proposed system is confirmed by the simulation. In four different load cases, four different compensation systems were applied in low voltage distribution station, respectively. Unbalance currents of distribution transformer secondary and node voltage drops in these cases were compared. Comparison results show that proposed compensation system has the best compensation effect.
Concentralized static var generator(SVG) compensation system has single compen-sation effect and distributed SVG compensation system without communication function can not distribute SVG's compensation capacities intelligently. Aiming at these problems, a compensation system based on SVGs' coordinated control strategy was proposed for three-phase unbalance load in low voltage distribution network. Communication bus and coordinated control strategy are introduced in the proposed system. After compensating the downstream unbalance current, the residual capacity of the downstream SVG is used to compensate the upstream SVGs in sequence. The low voltage problem of each node is further reduced by the reverse power flows from the downstream SVG to the upstream SVG. And then SVG's capacity in the proposed compensation system can be fully used. Meanwhile, the problems of the distribution transformer's unbalance current and the node's low voltage are synthetically solved. Simulations for actual effect evaluation of the proposed compensation system were done in Matlab/Simulink. Validity of the proposed system is confirmed by the simulation. In four different load cases, four different compensation systems were applied in low voltage distribution station, respectively. Unbalance currents of distribution transformer secondary and node voltage drops in these cases were compared. Comparison results show that proposed compensation system has the best compensation effect.
引文
[1]叶伟杰.江西电网配电变压器三相不平衡综合治理措施研究[D].南昌:南昌大学,2013.
[2]潘本仁,余侃胜,陈首昆,等.配电变压器三相不平衡分析及研究综述[J].江西电力,2012(5):63-65.Pan Benren,Yu Kansheng,Chen Shouqun,et al.Analysis and research summary of distribution transformer three-phase unbalance[J].Jiangxi Electric Power,2012(5):63-65.
[3]蒋浩,王淼.三相负荷不平衡对低压网损影响的分析[J].供用电,2008,25(3):68-70.Jiang Hao,Wang Miao.Analysis on the influence of unbalanced three-phase loads on LV line loss[J].Distribution&Utilization,2008,25(3):68-70.
[4]Bachry A,Styczynski Z A.An analysis of distribution system power quality problems resulting from load unbalance and harmonics[C]//Transmission and Distribution Conference and Exposition,Dallas,2003:763-766.
[5]Njafi A,Iskender I,Genc N,Evaluating and derating of three-phase distribution transformer under unbalanced voltage and unbalance load using finite element method[C]//IEEE 8th International Power Engineering and Optimization Conference(PEOCO),Langkawi,2014:160-165.
[6]Arunprasanth S,Arulampalam A,Binduhewa P J,et al.Dynamic reactive power compensator(DRPC)for unbalance load reactive power compensation[C]//IEEE 8th International Conference on Industrial and Information Systems,Peradeniya,2013:531-536.
[7]Vicente L M,Joaquin M R,Jose M P.Passive unbalance compensation device for three-phase variable loads[C]//The 10th International Conference on Environment and Electrical Engineering(EEEIC),Rome,2011:1-4.
[8]Pana A,Baloi A,Molnar-Matei F.Load balancing by unbalanced capacitive shunt compensation—A numerical approach[C]//The 14th International Conference on Harmonics and Quality of Power,Bergamo,2010:1-6.
[9]Youssef T A,Elsayed A T,Berzoy A,et al.Power quality enhancement for nonlinear unbalanced loads through improved active power filter control[C]//The40th Annual Conference of the IEEE Industrial Electronics Society,Dallas,2014:5202-5207.
[10]Saeed Y,Mahmoud E,Seyed H T.Presents a new topology for parallel compensator to improve the load unbalance in electrical energy distribution network[C]//The 20th Conference on Electrical Power Distribution Networks Conference(EPDC),Zahedan,2015:246-253.
[11]Karvekar S,Patil D.A novel technique for implementation of shunt active power filter under balanced and unbalanced load conditions circuits[C]//International Conference on Power and Computing Technologies(ICCPCT),Nagercoil,2013:1-5.
[12]辛业春,李国庆,王朝斌.无功和三相负荷不平衡的序分量法补偿控制[J].电力系统保护与控制,2014,42(14):72-78.Xin Yechun,Li Guoqing,Wang Chaobin.Compensation control of reactive power and three-phase unbalance load based on the method of sequence component[J].Power System Protection and Control,2014,42(14):72-78.
[13]阳同光,桂卫华.电网不平衡情况下并网逆变器多目标协调控制策略研究[J].电工技术学报,2015,30(11):148-157.Yang Tongguang,Gui Weihua.Research on multiobjective coordinated control strategies of gridconnected inverter under unbalanced voltage conditions[J].Transactions of China Electrotechnical Society,2015,30(11):148-157.
[14]Zhang S,Luo F L.A novel control strategy for load converter of renewable energy under unbalanced loading[C]//The 7th IEEE Conference on Industrial Electronics and Applications(ICIEA),Singapore,2012:1506-1511.
[15]阳同光,桂卫华.电网不平衡情况下并网逆变器控制策略综述[J].电工技术学报,2015,30(14):241-246.Yang Tongguang,Gui Weihua.An overview on control strategies of grid-connected inverter under unbalanced voltage conditions[J].Transactions of China Electrotechnical Society,2015,30(14):241-246.
[16]赵新,金新民,杨捷,等.并网逆变器新型不平衡控制方案[J].电工技术学报,2014,29(增刊1):257-265.Zhao Xin,Jin Xinmin,Yang Jie,et al.Novel unbalanced control scheme of grid-connected inverter[J].Transactions of China Electrotechnical Society,2014,29(S1):257-265.
[17]鞠洪兵,王德涛,张金斗.角形链式SVG补偿不平衡负载的控制策略[J].电气技术,2014,15(增刊1):18-23.Ju Hongbing,Wang Detao,Zhang Jindou.Control strategy of delta chain SVG for compensating unbalance load[J].Electrical Engineering,2014,15(S1):18-23.
[18]马皓,林钊,王小瑞.不平衡非线性负载下三相逆变器的建模与控制[J].电工技术学报,2015,30(18):83-95.Ma Hao,Lin Zhao,Wang Xiaorui.Modeling and control of three-phase inverter powering unbalanced and nonlinear loads[J].Transactions of China Electrotechnical Society,2015,30(18):83-95.
[19]周啸,金新民,唐芬,等.微电网孤岛工况下基于四桥臂变流器的不平衡负载分配策略[J].电工技术学报,2015,30(12):76-86.Zhou Xiao,Jin Xinmin,Tang Fen,et al.Four-leg converter based unbalanced load sharing method in islanding microgrid[J].Transactions of China Electrotechnical Society,2015,30(12):76-86.
[2]潘本仁,余侃胜,陈首昆,等.配电变压器三相不平衡分析及研究综述[J].江西电力,2012(5):63-65.Pan Benren,Yu Kansheng,Chen Shouqun,et al.Analysis and research summary of distribution transformer three-phase unbalance[J].Jiangxi Electric Power,2012(5):63-65.
[3]蒋浩,王淼.三相负荷不平衡对低压网损影响的分析[J].供用电,2008,25(3):68-70.Jiang Hao,Wang Miao.Analysis on the influence of unbalanced three-phase loads on LV line loss[J].Distribution&Utilization,2008,25(3):68-70.
[4]Bachry A,Styczynski Z A.An analysis of distribution system power quality problems resulting from load unbalance and harmonics[C]//Transmission and Distribution Conference and Exposition,Dallas,2003:763-766.
[5]Njafi A,Iskender I,Genc N,Evaluating and derating of three-phase distribution transformer under unbalanced voltage and unbalance load using finite element method[C]//IEEE 8th International Power Engineering and Optimization Conference(PEOCO),Langkawi,2014:160-165.
[6]Arunprasanth S,Arulampalam A,Binduhewa P J,et al.Dynamic reactive power compensator(DRPC)for unbalance load reactive power compensation[C]//IEEE 8th International Conference on Industrial and Information Systems,Peradeniya,2013:531-536.
[7]Vicente L M,Joaquin M R,Jose M P.Passive unbalance compensation device for three-phase variable loads[C]//The 10th International Conference on Environment and Electrical Engineering(EEEIC),Rome,2011:1-4.
[8]Pana A,Baloi A,Molnar-Matei F.Load balancing by unbalanced capacitive shunt compensation—A numerical approach[C]//The 14th International Conference on Harmonics and Quality of Power,Bergamo,2010:1-6.
[9]Youssef T A,Elsayed A T,Berzoy A,et al.Power quality enhancement for nonlinear unbalanced loads through improved active power filter control[C]//The40th Annual Conference of the IEEE Industrial Electronics Society,Dallas,2014:5202-5207.
[10]Saeed Y,Mahmoud E,Seyed H T.Presents a new topology for parallel compensator to improve the load unbalance in electrical energy distribution network[C]//The 20th Conference on Electrical Power Distribution Networks Conference(EPDC),Zahedan,2015:246-253.
[11]Karvekar S,Patil D.A novel technique for implementation of shunt active power filter under balanced and unbalanced load conditions circuits[C]//International Conference on Power and Computing Technologies(ICCPCT),Nagercoil,2013:1-5.
[12]辛业春,李国庆,王朝斌.无功和三相负荷不平衡的序分量法补偿控制[J].电力系统保护与控制,2014,42(14):72-78.Xin Yechun,Li Guoqing,Wang Chaobin.Compensation control of reactive power and three-phase unbalance load based on the method of sequence component[J].Power System Protection and Control,2014,42(14):72-78.
[13]阳同光,桂卫华.电网不平衡情况下并网逆变器多目标协调控制策略研究[J].电工技术学报,2015,30(11):148-157.Yang Tongguang,Gui Weihua.Research on multiobjective coordinated control strategies of gridconnected inverter under unbalanced voltage conditions[J].Transactions of China Electrotechnical Society,2015,30(11):148-157.
[14]Zhang S,Luo F L.A novel control strategy for load converter of renewable energy under unbalanced loading[C]//The 7th IEEE Conference on Industrial Electronics and Applications(ICIEA),Singapore,2012:1506-1511.
[15]阳同光,桂卫华.电网不平衡情况下并网逆变器控制策略综述[J].电工技术学报,2015,30(14):241-246.Yang Tongguang,Gui Weihua.An overview on control strategies of grid-connected inverter under unbalanced voltage conditions[J].Transactions of China Electrotechnical Society,2015,30(14):241-246.
[16]赵新,金新民,杨捷,等.并网逆变器新型不平衡控制方案[J].电工技术学报,2014,29(增刊1):257-265.Zhao Xin,Jin Xinmin,Yang Jie,et al.Novel unbalanced control scheme of grid-connected inverter[J].Transactions of China Electrotechnical Society,2014,29(S1):257-265.
[17]鞠洪兵,王德涛,张金斗.角形链式SVG补偿不平衡负载的控制策略[J].电气技术,2014,15(增刊1):18-23.Ju Hongbing,Wang Detao,Zhang Jindou.Control strategy of delta chain SVG for compensating unbalance load[J].Electrical Engineering,2014,15(S1):18-23.
[18]马皓,林钊,王小瑞.不平衡非线性负载下三相逆变器的建模与控制[J].电工技术学报,2015,30(18):83-95.Ma Hao,Lin Zhao,Wang Xiaorui.Modeling and control of three-phase inverter powering unbalanced and nonlinear loads[J].Transactions of China Electrotechnical Society,2015,30(18):83-95.
[19]周啸,金新民,唐芬,等.微电网孤岛工况下基于四桥臂变流器的不平衡负载分配策略[J].电工技术学报,2015,30(12):76-86.Zhou Xiao,Jin Xinmin,Tang Fen,et al.Four-leg converter based unbalanced load sharing method in islanding microgrid[J].Transactions of China Electrotechnical Society,2015,30(12):76-86.