独立运行微电网的故障特性分析及其线路保护研究
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摘要
针对变流器接口电源区别于传统电源的故障特性和其分散接入微电网的拓扑结构使传统配电网保护难以快速可靠动作的问题,推导独立运行微电网不同类型电源支路的等效正序故障分量阻抗解析表达式,分析采用不同控制策略时,在故障前负荷情况、故障后输出电流幅值及外部等值阻抗影响下等效正序故障分量阻抗角的变化规律,并对微电网中不同位置正序故障分量方向元件的动作性能差异进行论证。进而提出一种基于线路正序电流故障分量与分布式光伏电源故障前电流相位比较的故障方向判断方法,并利用光伏支路电流突变量和光伏功率参考值突变量构造启动逻辑,形成闭锁式保护动作方案,可以以最小范围快速切除不同类型故障线路。PSCAD/EMTDC仿真结果验证了所提方案的正确性。
Since differences of fault characteristic between converter-interfaced source and traditional generator and topology of distributed access of converter-interfaced source,it is difficult for traditional distribution network protection to act quickly and reliably. The analytical expressions of equivalent positive-sequence fault component impe-dance of different power source branches in independent microgrid are deduced,the variation rules of impedance angle of equivalent positive sequence fault component under influences of load conditions before fault,output current amplitude after fault and external equivalent impedance with different control strategies are analyzed,and the action performance difference of positive-sequence fault directional elements at different locations in microgrid is analyzed. On this basis,a fault direction judgment method is proposed based on phase comparison between positive-sequence fault component current and the distributed PV(PhotoVoltaic) current before fault. The start-up logic is constructed by using increments of PV branch current and PV power reference value to form a locking-type protection scheme,which is able to remove lines of all types of fault in a minimum range. The correctness of the proposed scheme is ve-rified by results of PSCAD/EMTDC simulation.
Since differences of fault characteristic between converter-interfaced source and traditional generator and topology of distributed access of converter-interfaced source,it is difficult for traditional distribution network protection to act quickly and reliably. The analytical expressions of equivalent positive-sequence fault component impe-dance of different power source branches in independent microgrid are deduced,the variation rules of impedance angle of equivalent positive sequence fault component under influences of load conditions before fault,output current amplitude after fault and external equivalent impedance with different control strategies are analyzed,and the action performance difference of positive-sequence fault directional elements at different locations in microgrid is analyzed. On this basis,a fault direction judgment method is proposed based on phase comparison between positive-sequence fault component current and the distributed PV(PhotoVoltaic) current before fault. The start-up logic is constructed by using increments of PV branch current and PV power reference value to form a locking-type protection scheme,which is able to remove lines of all types of fault in a minimum range. The correctness of the proposed scheme is ve-rified by results of PSCAD/EMTDC simulation.
引文
[1] LAAKSONEN H J. Protection principles for future microgrids[J]. IEEE Transactions on Power Electronics,2010,25(12):2910-2918.
[2] BARAN M,EI-MARKABY I. Fault analysis on distribution feeders with distributed generators[J]. IEEE Transactions on Power Systems,2005,20(4):1757-1764.
[3] 韩奕,张东霞. 含逆变型分布式电源的微网故障特征分析[J]. 电网技术,2011,35(10):147-152.HAN Yi,ZHANG Dongxia. Fault analysis of microgrid composed by inverter-based distributed generations[J]. Power System Technolo-gy,2011,35(10):147-152.
[4] 曾德辉,潘国清,王钢,等. 含V/f控制DG的微电网故障分析方法[J]. 中国电机工程学报,2014,34(16):2604-2611.ZENG Dehui,PAN Guoqing,WANG Gang,et al. Method of fault analysis on microgrid with distributed generation based on V/f control strategy[J]. Proceedings of the CSEE,2014,34(16):2604-2611.
[5] KABIRI R,HOLMES D G,MCGRATH B P. Control of active and reactive power ripple to mitigate unbalanced grid voltages[J]. IEEE Transactions on Industry Applications,2016,52(2):1660-1668.
[6] 金强. 分布式电源故障特性分析及微电网保护原理的研究[D]. 天津:天津大学,2012.JIN Qiang. Research on analysis of distributed generation fault cha-racteristics and protection schemes for micro-grid [D]. Tianjin:Tianjin University,2012.
[7] 汪冬辉,姚旭,张坤贤,等. 独立运行微电网的故障特征分析[J]. 电力自动化设备,2014,34(3):52-58.WANG Donghui,YAO Xu,ZHANG Kunxian,et al. Analysis on fault characteristics of independent microgrid[J]. Electric Power Automation Equipment,2014,34(3):52-58.
[8] 黄文焘,邰能灵,杨霞. 微网反时限低阻抗保护方案[J]. 中国电机工程学报,2014,34(1):105-114.HUANG Wentao,TAI Nengling,YANG Xia. Inverse-time low-impe-dance protection scheme for microgrids[J]. Proceedings of the CSEE,2014,34(1):105-114.
[9] 许偲轩,陆于平,王业. 基于边电压的反时限微网保护方案[J]. 电力系统自动化,2014,38(1):68-73.XU Sixuan,LU Yuping,WANG Ye. A section voltage based inverse timing protection method for microgrid[J]. Automation of Electric Power Systems,2014,38(1):68-73.
[10] 姜斌,牟龙华,郭文明,等. 基于母线测量导纳变化的微电网保护[J]. 电网技术,2015,39(6):1751-1758.JIANG Bin,MU Longhua,GUO Wenming,et al. Microgrid protection based on change of measured bus admittance[J]. Power System Technology,2015,39(6):1751-1758.
[11] 林湘宁,袁硕,翁汉琍,等. 实现有限选择性的低压微网区域保护[J]. 电网技术,2012,36(4):149-154.LIN Xiangning,YUAN Shuo,WENG Hanli,et al. Study on finite selectivity based regional protection suitable for low-voltage microgrid[J]. Power System Technology,2012,36(4):149-154.
[12] 王志文,陈来军,郑天文,等. 采用搜索保护与差动保护的光伏微电网综合保护策略[J]. 电力系统保护与控制,2014,42(18):14-19.WANG Zhiwen,CHEN Laijun,ZHEN Tianwen,et al. A comprehensive protection scheme for photovoltaic microgrid using scan protection and differential protection[J]. Power System Protection and Control,2014,42(18):14-19.
[13] 周涵,牟龙华,郭文明. 基于故障分量的孤岛微电网保护[J]. 电工技术学报,2017,32(17):11-20.ZHOU Han,MU Longhua,GUO Wenming. Islanded microgrid protection based on fault components[J]. Transactions of China Electrotechnical Society,2017,32(17):11-20.
[14] 徐萌. 微电网新型保护控制方案与实现技术[D]. 济南:山东大学,2017.XU Meng. Novel protection and control scheme and implementation technology for microgrid[D]. Jinan:Shandong University,2017.
[15] 徐萌,邹贵彬,陈宁,等. 基于故障超前相的有源配电网能量方向纵联保护方法[J]. 电力自动化设备,2017,37(1):58-64.XU Meng,ZOU Guibin,CHEN Ning,et al. Energy-directional pilot protection based on leading-phase for active distribution network[J]. Electric Power Automation Equipment,2017,37(1):58-64.
[16] 李斌,宝海龙,郭力. 光储微电网孤岛系统的储能控制策略[J]. 电力自动化设备,2014,34(3):8-15.LI Bin,BAO Hailong,GUO Li. Interregional available transfer capability research based on interior point method with consideration of wind power penetration level[J]. Electric Power Automation Equipment,2014,34(3):8-15.
[17] 黄涛,陆于平,蔡超. DFIG等效序突变量阻抗相角特征对故障分量方向元件的影响分析[J]. 中国电机工程学报,2016,36(14):3929-3939.HUANG Tao,LU Yuping,CAI Chao. Analysis of phase angle characteristics of DFIG equivalent sequence superimposed impedances and its impact on fault components based direction relay[J]. Proceedings of the CSEE,2016,36(14):3929-3939.
[18] 郭力,富晓鹏,李霞林,等. 独立交流微网中电池储能与柴油发电机的协调控制[J]. 中国电机工程学报,2012,32(25):70-78.GUO Li,FU Xiaopeng,LI Xialin,et al. Coordinated control of battery storage and diesel generators in isolated AC microgrid systems[J]. Proceedings of the CSEE,2012,32(25):70-78.
[19] 牟晓春,毕大强,任先文. 低压微网综合控制策略设计[J]. 电力系统自动化,2010,34(19):91-96.MOU Xiaochun,BI Daqiang,REN Xianwen. Study on control strategies of a low voltage microgrid[J]. Automation of Electric Power Systems,2010,34(19):91-96.
[20] 潘国清,曾德辉,王钢,等. 含PQ控制逆变型分布式电源的配电网故障分析方法[J]. 中国电机工程学报,2014,34(4):555-561.PAN Guoqing,ZENG Dehui,WANG Gang,et al. Fault analysis on distribution network with inverter interfaced distributed generations based on PQ control strategy[J]. Proceedings of the CSEE,2014,34(4):555-561.
[2] BARAN M,EI-MARKABY I. Fault analysis on distribution feeders with distributed generators[J]. IEEE Transactions on Power Systems,2005,20(4):1757-1764.
[3] 韩奕,张东霞. 含逆变型分布式电源的微网故障特征分析[J]. 电网技术,2011,35(10):147-152.HAN Yi,ZHANG Dongxia. Fault analysis of microgrid composed by inverter-based distributed generations[J]. Power System Technolo-gy,2011,35(10):147-152.
[4] 曾德辉,潘国清,王钢,等. 含V/f控制DG的微电网故障分析方法[J]. 中国电机工程学报,2014,34(16):2604-2611.ZENG Dehui,PAN Guoqing,WANG Gang,et al. Method of fault analysis on microgrid with distributed generation based on V/f control strategy[J]. Proceedings of the CSEE,2014,34(16):2604-2611.
[5] KABIRI R,HOLMES D G,MCGRATH B P. Control of active and reactive power ripple to mitigate unbalanced grid voltages[J]. IEEE Transactions on Industry Applications,2016,52(2):1660-1668.
[6] 金强. 分布式电源故障特性分析及微电网保护原理的研究[D]. 天津:天津大学,2012.JIN Qiang. Research on analysis of distributed generation fault cha-racteristics and protection schemes for micro-grid [D]. Tianjin:Tianjin University,2012.
[7] 汪冬辉,姚旭,张坤贤,等. 独立运行微电网的故障特征分析[J]. 电力自动化设备,2014,34(3):52-58.WANG Donghui,YAO Xu,ZHANG Kunxian,et al. Analysis on fault characteristics of independent microgrid[J]. Electric Power Automation Equipment,2014,34(3):52-58.
[8] 黄文焘,邰能灵,杨霞. 微网反时限低阻抗保护方案[J]. 中国电机工程学报,2014,34(1):105-114.HUANG Wentao,TAI Nengling,YANG Xia. Inverse-time low-impe-dance protection scheme for microgrids[J]. Proceedings of the CSEE,2014,34(1):105-114.
[9] 许偲轩,陆于平,王业. 基于边电压的反时限微网保护方案[J]. 电力系统自动化,2014,38(1):68-73.XU Sixuan,LU Yuping,WANG Ye. A section voltage based inverse timing protection method for microgrid[J]. Automation of Electric Power Systems,2014,38(1):68-73.
[10] 姜斌,牟龙华,郭文明,等. 基于母线测量导纳变化的微电网保护[J]. 电网技术,2015,39(6):1751-1758.JIANG Bin,MU Longhua,GUO Wenming,et al. Microgrid protection based on change of measured bus admittance[J]. Power System Technology,2015,39(6):1751-1758.
[11] 林湘宁,袁硕,翁汉琍,等. 实现有限选择性的低压微网区域保护[J]. 电网技术,2012,36(4):149-154.LIN Xiangning,YUAN Shuo,WENG Hanli,et al. Study on finite selectivity based regional protection suitable for low-voltage microgrid[J]. Power System Technology,2012,36(4):149-154.
[12] 王志文,陈来军,郑天文,等. 采用搜索保护与差动保护的光伏微电网综合保护策略[J]. 电力系统保护与控制,2014,42(18):14-19.WANG Zhiwen,CHEN Laijun,ZHEN Tianwen,et al. A comprehensive protection scheme for photovoltaic microgrid using scan protection and differential protection[J]. Power System Protection and Control,2014,42(18):14-19.
[13] 周涵,牟龙华,郭文明. 基于故障分量的孤岛微电网保护[J]. 电工技术学报,2017,32(17):11-20.ZHOU Han,MU Longhua,GUO Wenming. Islanded microgrid protection based on fault components[J]. Transactions of China Electrotechnical Society,2017,32(17):11-20.
[14] 徐萌. 微电网新型保护控制方案与实现技术[D]. 济南:山东大学,2017.XU Meng. Novel protection and control scheme and implementation technology for microgrid[D]. Jinan:Shandong University,2017.
[15] 徐萌,邹贵彬,陈宁,等. 基于故障超前相的有源配电网能量方向纵联保护方法[J]. 电力自动化设备,2017,37(1):58-64.XU Meng,ZOU Guibin,CHEN Ning,et al. Energy-directional pilot protection based on leading-phase for active distribution network[J]. Electric Power Automation Equipment,2017,37(1):58-64.
[16] 李斌,宝海龙,郭力. 光储微电网孤岛系统的储能控制策略[J]. 电力自动化设备,2014,34(3):8-15.LI Bin,BAO Hailong,GUO Li. Interregional available transfer capability research based on interior point method with consideration of wind power penetration level[J]. Electric Power Automation Equipment,2014,34(3):8-15.
[17] 黄涛,陆于平,蔡超. DFIG等效序突变量阻抗相角特征对故障分量方向元件的影响分析[J]. 中国电机工程学报,2016,36(14):3929-3939.HUANG Tao,LU Yuping,CAI Chao. Analysis of phase angle characteristics of DFIG equivalent sequence superimposed impedances and its impact on fault components based direction relay[J]. Proceedings of the CSEE,2016,36(14):3929-3939.
[18] 郭力,富晓鹏,李霞林,等. 独立交流微网中电池储能与柴油发电机的协调控制[J]. 中国电机工程学报,2012,32(25):70-78.GUO Li,FU Xiaopeng,LI Xialin,et al. Coordinated control of battery storage and diesel generators in isolated AC microgrid systems[J]. Proceedings of the CSEE,2012,32(25):70-78.
[19] 牟晓春,毕大强,任先文. 低压微网综合控制策略设计[J]. 电力系统自动化,2010,34(19):91-96.MOU Xiaochun,BI Daqiang,REN Xianwen. Study on control strategies of a low voltage microgrid[J]. Automation of Electric Power Systems,2010,34(19):91-96.
[20] 潘国清,曾德辉,王钢,等. 含PQ控制逆变型分布式电源的配电网故障分析方法[J]. 中国电机工程学报,2014,34(4):555-561.PAN Guoqing,ZENG Dehui,WANG Gang,et al. Fault analysis on distribution network with inverter interfaced distributed generations based on PQ control strategy[J]. Proceedings of the CSEE,2014,34(4):555-561.