基于双端数据的混合输电线路故障测距算法
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摘要
随着中国土地资源的越来越珍贵,以及美化市容市貌的要求,架空线-高压电缆混合输电线路的应用越来越广泛。混合输电线路故障测距技术能加快对故障线路的检修,减少因停电造成的损失和负面影响。因此,研究混合输电线路故障测距技术具有重大的意义。
为了提高架空线-高压电缆混合输电线路故障测距的精度,并解决测距的伪根问题,本文采用了能提高故障测距精度的分布参数模型,提出了一种基于双端不同步数据的混合输电线路故障测距改进算法,并应用于自动重合闸策略。MATLAB仿真表明,该测距算法不受伪根、过渡电阻、故障类型和位置以及不同步相角等因素的影响,能够实现快速准确地故障测距。本文的主要工作和成果如下:
1.综述了现有的各种故障测距算法,比较各种算法的优缺点,将研究对象定为基于双端不同步数据的混合输电线路故障测距算法。
2.对架空线-高压电缆混合输电线路进行数学建模,通过分析混合输电线路沿线电压伪根产生的原因,提出了一种改进的二分搜索测距算法。并通过误差分析提出了混合输电线路的参数自适应算法,减少外部因素造成的影响。
3.分析了电力系统中常用的滤波算法,采用高精度又具实时性的移动数据窗傅里叶滤波改进算法,对双端的工频数据进行预处理。用对称分量法进行相模变换,得到序分量。分析了双端数据不同步采样问题,针对混合输电线路提出了一种不同步角算法。
4.通过MATLAB仿真,验证了此混合输电线路故障测距改进算法能有效排除伪根,准确快速地测出故障距离。仿真还验证了移动数据窗傅里叶滤波的性能,能高精度和快速地获得故障数据中的基波分量。另外仿真还验证了伪根的存在。
5.研究了将混合输电线路故障测距技术应用于自动重合闸的配合策略,来提高电力系统的安全可靠性。
6.最后,对全文进行总结,并对进一步的研究提出一些展望。
The application of hybrid transmission lines has been more and more widely used as the lack of land resources and the demands of beautifying the city appearance. Hybrid transmission lines fault location technique is able to accelerate the overhaul of fault lines and minimize the loss and impact caused by power failure. Therefore, studying hybrid transmission lines fault location technique is of great significance.
In order to improve the accuracy of hybrid transmission lines fault location, and solve the problem of pseudo root, the paper used a distributed parameter model to improve the accuracy, and it also brought forward a improved algorithms based on two-terminal asynchronous data of fault location, which are applied to auto-reclosure strategy. MATLAB simulation showed that this location algorithms was unaffected with the factors of pseudo root, transition resistance, fault type, fault location and non-synchronous angle etc. to achieve fast and accurate fault location. The main work and achievements are as follows:
1.Giving an overview of all the fault location techniques technologies and comparing their advantages and shortcomings, the subject of this study was based on a fault location algorithms based on two-terminal asynchronous data for hybrid transmission lines.
2. In this paper, it made a mathematical model for hybrid transmission lines, and analyzed the causes of pseudo root according to voltage distribution along the transmission lines of hybrid transmission lines, then proposed an improved binary search algorithms. It proposed the parameter adaptive algorithms of hybrid transmission lines based on error analysis to reduce the impact of external factors.
3. The paper analyzed common filter algorithms used in power system, it adopted an improved mobile data-window Fourier filtering algorithms with high precision and real-time to pretreatment the two-terminal data of power frequency before fault location. It converted three-phase component to sequence components by using symmetric component algorithms. The paper analyzed the non-asynchronous sampling of two-terminal data, and proposed an non-asynchronous Angle algorithms for hybrid transmission lines.
4. Via MATLAB simulation, it verified this hybrid transmission lines fault location algorithms can effectively eliminate pseudo root, and measure the distance to fault quickly and accurately. Meanwhile, the simulation results demonstrated that the mobile data window Fourier filter can obtain the fundamental component from fault data with rapidity and high-precision. In addition the simulation also proved the existence of pseudo root.
5. This paper also applied the fault location technique of hybrid transmission lines to coordination strategy of auto-reclosure to improve the safety and reliability of the power system. 6. Finally, make a summary of the whole paper, and put forward some prospect of further research.
为了提高架空线-高压电缆混合输电线路故障测距的精度,并解决测距的伪根问题,本文采用了能提高故障测距精度的分布参数模型,提出了一种基于双端不同步数据的混合输电线路故障测距改进算法,并应用于自动重合闸策略。MATLAB仿真表明,该测距算法不受伪根、过渡电阻、故障类型和位置以及不同步相角等因素的影响,能够实现快速准确地故障测距。本文的主要工作和成果如下:
1.综述了现有的各种故障测距算法,比较各种算法的优缺点,将研究对象定为基于双端不同步数据的混合输电线路故障测距算法。
2.对架空线-高压电缆混合输电线路进行数学建模,通过分析混合输电线路沿线电压伪根产生的原因,提出了一种改进的二分搜索测距算法。并通过误差分析提出了混合输电线路的参数自适应算法,减少外部因素造成的影响。
3.分析了电力系统中常用的滤波算法,采用高精度又具实时性的移动数据窗傅里叶滤波改进算法,对双端的工频数据进行预处理。用对称分量法进行相模变换,得到序分量。分析了双端数据不同步采样问题,针对混合输电线路提出了一种不同步角算法。
4.通过MATLAB仿真,验证了此混合输电线路故障测距改进算法能有效排除伪根,准确快速地测出故障距离。仿真还验证了移动数据窗傅里叶滤波的性能,能高精度和快速地获得故障数据中的基波分量。另外仿真还验证了伪根的存在。
5.研究了将混合输电线路故障测距技术应用于自动重合闸的配合策略,来提高电力系统的安全可靠性。
6.最后,对全文进行总结,并对进一步的研究提出一些展望。
The application of hybrid transmission lines has been more and more widely used as the lack of land resources and the demands of beautifying the city appearance. Hybrid transmission lines fault location technique is able to accelerate the overhaul of fault lines and minimize the loss and impact caused by power failure. Therefore, studying hybrid transmission lines fault location technique is of great significance.
In order to improve the accuracy of hybrid transmission lines fault location, and solve the problem of pseudo root, the paper used a distributed parameter model to improve the accuracy, and it also brought forward a improved algorithms based on two-terminal asynchronous data of fault location, which are applied to auto-reclosure strategy. MATLAB simulation showed that this location algorithms was unaffected with the factors of pseudo root, transition resistance, fault type, fault location and non-synchronous angle etc. to achieve fast and accurate fault location. The main work and achievements are as follows:
1.Giving an overview of all the fault location techniques technologies and comparing their advantages and shortcomings, the subject of this study was based on a fault location algorithms based on two-terminal asynchronous data for hybrid transmission lines.
2. In this paper, it made a mathematical model for hybrid transmission lines, and analyzed the causes of pseudo root according to voltage distribution along the transmission lines of hybrid transmission lines, then proposed an improved binary search algorithms. It proposed the parameter adaptive algorithms of hybrid transmission lines based on error analysis to reduce the impact of external factors.
3. The paper analyzed common filter algorithms used in power system, it adopted an improved mobile data-window Fourier filtering algorithms with high precision and real-time to pretreatment the two-terminal data of power frequency before fault location. It converted three-phase component to sequence components by using symmetric component algorithms. The paper analyzed the non-asynchronous sampling of two-terminal data, and proposed an non-asynchronous Angle algorithms for hybrid transmission lines.
4. Via MATLAB simulation, it verified this hybrid transmission lines fault location algorithms can effectively eliminate pseudo root, and measure the distance to fault quickly and accurately. Meanwhile, the simulation results demonstrated that the mobile data window Fourier filter can obtain the fundamental component from fault data with rapidity and high-precision. In addition the simulation also proved the existence of pseudo root.
5. This paper also applied the fault location technique of hybrid transmission lines to coordination strategy of auto-reclosure to improve the safety and reliability of the power system. 6. Finally, make a summary of the whole paper, and put forward some prospect of further research.
引文
[1]岑建明.输电线路故障测距的研究[D].浙江:浙江大学电气工程学院, 2007.
[2]徐鹏.输电线路故障测距研究[D].广州:华南理工大学, 2004.
[3]于桂音,陈平,徐丙垠等.基于行波原理的优化组合故障测距技术[J].继电器, 2008, 36(9):11-15, 20.
[4] Lee A C. Ground-Fault-Location Indicator [J]. Power Apparatus and System, IEEE Transactions on, 1958, 77(2): 1370-1372.
[5]张方军.高压输电线故障定位方法研究[J].广东输电与变电技术, 2009, 11(4): 4-8.
[6]全玉生.高压架空输电线路故障测距新算法的研究[D].西安:西安交通大学, 1999.
[7] Sachdev M S, Agarwal R. A technique for estimating transmission line fault locations from digital impedance relay measurements [J]. Power Delivery, IEEE Transactions on, 1988, 3(1): 121-129.
[8] Johns A T, Jamali S. Accurate fault location technique for power transmission lines [J]. Generation, Transmission and Distribution, IEE Proceedings C, 1990, 137(6): 396-402.
[9]蔡德礼.高压输电线路故障点定位的一种新的计算机方法[J].重庆大学学报, 1982, 6(2): 1-18.
[10]刘飞.信息处理智能方法及其在高压输电线路故障分析中的应用[D].天津:天津大学, 2005.
[11]陈方人.行波测距在电力线路故障查找中的应用[J].中国高新技术企业, 2010, (21): 124-125.
[12]董新洲.小波理论应用于输电线路行波故障测距研究[D].西安:西安交通大学, 1996.
[13]杨拯.行波技术在电力系统继电保护中的应用探讨[J].陕西电力, 2009, 37(10): 81-83.
[14]陈平,葛耀中,徐丙垠等.现代行波故障测距原理及其在实测故障分析中的应用-A型原理[J].继电器, 2004, 32(2): 13-18, 43.
[15]陈平,葛耀中,徐丙垠等.现代行波故障测距原理及其在实测故障分析中的应用-D型原理[J].继电器, 2004, 32(3): 14-17, 28.
[16]宋永贵.现代行波故障测距原理在电力系统中的实际应用[J].中国科技财富, 2010, 4(8): 172-173.
[17]潘江蒙,陈利军,宋励鑫.输电线路阻抗测距法和单端行波测距法的对比仿真分析[J].西南民族大学学报(自然科学版), 2010, 36(4): 659-663.
[18]余健栋,蒲晓羽.基于线路参数变化的双端行波故障测距研究[J].机电设备, 2010, (4): 9-12.
[19]杨永强,束洪春,李旭前.电力系统行波测距综述[J].云南电力技术, 2007, 35(5): 1-2.
[20]时昌盛,苏良虎.行波测距在电力系统中应用[J].电气开关, 2010, 48(1): 64-66, 70.
[21]陈旋,苏晓.故障线路行波测距误差分析[J].广西电力, 2009, 32(6): 43-45.
[22]杨志超.高压输电线路故障测距方法比较[J].油气田地面工程, 2009, 28(7): 56-57.
[23] Takagi T, Yamakoshi Y, Baba J, et al. A New Algorithm of an Accurate Fault Location for EHV/UHV Transmission Lines: Part I - Fourier Transformation Method [J]. Power Apparatus and Systems, IEEE Transactions on, 1981, PAS-100(3): 1316-1323.
[24] Takagi T, Yamakoshi Y, Baba J, et al. A New Algorithm of an Accurate Fault Location for EHV/UHV Transmission Lines: Part II - Laplace Transform Method [J]. Power Apparatus and Systems, IEEETransactions on, 1982, PAS-101(3): 564-573.
[25]马文骐,毛玉华,杨秀媛. RLC线路模型下的故障测距研究[J].电网技术, 2000, 24(7): 10-13.
[26]束洪春,司大军,葛耀中等.三角形环网输电线路故障测距新算法及其实现[J].电网技术, 2000, 24(4): 34-39.
[27] Djuric M B, Terzija V V. A new approach to the arcing faults detection for fast auto-reclosure in transmission systems [J]. Power Delivery, IEEE Transactions on, 1995, 10(4): 1793-1798.
[28] Djuric M B, Radojevic Z M, Terzija V V. Time domain solution of faults distance estimation and arcing faults detection on overhead lines [J]. Power Delivery, IEEE Transactions on, 1999, 14(1): 60-67.
[29] Wailar D L, Elangovan S, Liew A C. Fault impedance estimation algorithms for digital distance relaying [J]. Power Delivery, IEEE Transactions on, 1994, 9(3): 1375-1383.
[30]孙立山,陈学允.使用输电线路双端数据的故障测距研究[J].哈尔滨工业大学学报, 1999, 31(2): 58-60.
[31]陈铮,苏进喜,吴欣荣等.基于分布参数模型的高压输电线路故障测距算法[J].电网技术, 2000, 24(11): 31-33.
[32] Girgis A A, Hart D G, Peterson W L. A new fault location technique for two and three terminal lines [J]. Power Delivery, IEEE Transactions on, 1992, 7(1): 98-107.
[33] Girgis A A, Fallon C M. Fault location techniques for radial and loop transmission systems using digital fault recorded data [J]. Power Delivery, IEEE Transactions on, 1992, 7(4): 1936-1945.
[34]郭丽军.基于双端数据的高压输电线路故障测距新算法的研究[D].北京:华北电力大学, 2005.
[35]李骏,范春菊.基于小波分析的电缆-架空线混合输电线路行波故障测距方法[J].电网技术, 2006, 30(9): 92-97.
[36]陈宾,陈皓,刘伟.基于分布参数模型的混合输电线路故障测距和重合闸的研究[J].四川电力技术, 2010, 33(2): 42-44, 63.
[37]杨军,伍咏红,江文波.基于双端故障信息的高压电缆?架空线混合输电线路故障测距方法[J].电网技术, 2010, 34(1) :208-212.
[38]吴承恩,邰能灵,郁惟铺.超高压电缆-架空线混合输电线路故障测寻方法[J].电力系统自动化, 2005, 29(10): 26-30.
[39]乔幕新.架空线路的故障分析[J].中国科技纵横, 2010, (7): 125-125.
[40]蔡建伟.浅谈电力电缆产生故障的原因及对策[J].科技致富向导, 2010, 3(5): 95-98.
[41]刘伟,陈皓.基于分布参数模型的混合输电线路故障测距新算法[J].电力系统保护与控制, 2009, 37(24): 76-80.
[42]葛耀中.新型继电保护和故障测距的原理与技术[M].西安:西安交通大学出版社, 2007.
[43]唐信,陈兴洲.架空线弧垂观测检查及调整[J].中国科技信息, 2009, 8(17): 40-40, 47.
[44]冉波.用pspice对电力采集装置前置低通滤波器进行分析[J].西南民族大学学报(自然科学版), 2006, 32(5): 1058-1061.
[45]姚亮,胡再超,杭泱.常见傅氏变换的滤波性能分析[J].电力自动化设备, 2008, (1): 73-76.
[46]刘毅,温渤婴.差分与傅氏变换相结合算法在微机电流保护中的应用[J].继电器, 2000, 28(8): 36-38.
[47]黄飞腾,陈明军,郑慧.故障测距中的差分傅氏滤波改进算法[J].电力系统保护与控制, 2009, 37(11): 62-65.
[48]邓自立,马建为. MA模型参数估计的两段最小二乘法及其在自校正跟踪滤波器中的应用[J].科学技术与工程, 2003, 3(1): 3-5.
[49]苏文辉,李钢.一种能滤去衰减直流分量的改进全周傅氏算法[J].电力系统自动化, 2002, 26(23): 42-44.
[50]阎爱玲,杨新华.基于小波变换和相模变换的电力电缆故障测距[J].甘肃科学学报, 2009, 21(2): 141-143.
[51]张晓飞. GPS同步时钟技术在电力系统中的应用分析[J].广西电业, 2009, (4): 82-83, 78.
[52]王正林.精通MATLAB7 [M].北京:电子工业出版社, 2006.
[53]韩丽娜,杨志坚,李虎.电磁暂态程序EMTP在电力系统的应用[J].广东输电与变电技术, 2006, (2): 19-22.
[54]张艳秋,孟为民,陶磊.超高压输电线路自动重合闸技术分析[J].企业技术开发, 2010, 29(2): 20-21.
[55]李方永.自动重合闸在输电线路上的运用[J].中国高新技术企业, 2010, (16): 95-96.
[56]黄震,陈平.基于行波原理的110kV架空线-电缆混合输电线路自适应重合闸控制技术研究[J].四川电力技术, 2008, 31(B11): 1-3, 18.
[2]徐鹏.输电线路故障测距研究[D].广州:华南理工大学, 2004.
[3]于桂音,陈平,徐丙垠等.基于行波原理的优化组合故障测距技术[J].继电器, 2008, 36(9):11-15, 20.
[4] Lee A C. Ground-Fault-Location Indicator [J]. Power Apparatus and System, IEEE Transactions on, 1958, 77(2): 1370-1372.
[5]张方军.高压输电线故障定位方法研究[J].广东输电与变电技术, 2009, 11(4): 4-8.
[6]全玉生.高压架空输电线路故障测距新算法的研究[D].西安:西安交通大学, 1999.
[7] Sachdev M S, Agarwal R. A technique for estimating transmission line fault locations from digital impedance relay measurements [J]. Power Delivery, IEEE Transactions on, 1988, 3(1): 121-129.
[8] Johns A T, Jamali S. Accurate fault location technique for power transmission lines [J]. Generation, Transmission and Distribution, IEE Proceedings C, 1990, 137(6): 396-402.
[9]蔡德礼.高压输电线路故障点定位的一种新的计算机方法[J].重庆大学学报, 1982, 6(2): 1-18.
[10]刘飞.信息处理智能方法及其在高压输电线路故障分析中的应用[D].天津:天津大学, 2005.
[11]陈方人.行波测距在电力线路故障查找中的应用[J].中国高新技术企业, 2010, (21): 124-125.
[12]董新洲.小波理论应用于输电线路行波故障测距研究[D].西安:西安交通大学, 1996.
[13]杨拯.行波技术在电力系统继电保护中的应用探讨[J].陕西电力, 2009, 37(10): 81-83.
[14]陈平,葛耀中,徐丙垠等.现代行波故障测距原理及其在实测故障分析中的应用-A型原理[J].继电器, 2004, 32(2): 13-18, 43.
[15]陈平,葛耀中,徐丙垠等.现代行波故障测距原理及其在实测故障分析中的应用-D型原理[J].继电器, 2004, 32(3): 14-17, 28.
[16]宋永贵.现代行波故障测距原理在电力系统中的实际应用[J].中国科技财富, 2010, 4(8): 172-173.
[17]潘江蒙,陈利军,宋励鑫.输电线路阻抗测距法和单端行波测距法的对比仿真分析[J].西南民族大学学报(自然科学版), 2010, 36(4): 659-663.
[18]余健栋,蒲晓羽.基于线路参数变化的双端行波故障测距研究[J].机电设备, 2010, (4): 9-12.
[19]杨永强,束洪春,李旭前.电力系统行波测距综述[J].云南电力技术, 2007, 35(5): 1-2.
[20]时昌盛,苏良虎.行波测距在电力系统中应用[J].电气开关, 2010, 48(1): 64-66, 70.
[21]陈旋,苏晓.故障线路行波测距误差分析[J].广西电力, 2009, 32(6): 43-45.
[22]杨志超.高压输电线路故障测距方法比较[J].油气田地面工程, 2009, 28(7): 56-57.
[23] Takagi T, Yamakoshi Y, Baba J, et al. A New Algorithm of an Accurate Fault Location for EHV/UHV Transmission Lines: Part I - Fourier Transformation Method [J]. Power Apparatus and Systems, IEEE Transactions on, 1981, PAS-100(3): 1316-1323.
[24] Takagi T, Yamakoshi Y, Baba J, et al. A New Algorithm of an Accurate Fault Location for EHV/UHV Transmission Lines: Part II - Laplace Transform Method [J]. Power Apparatus and Systems, IEEETransactions on, 1982, PAS-101(3): 564-573.
[25]马文骐,毛玉华,杨秀媛. RLC线路模型下的故障测距研究[J].电网技术, 2000, 24(7): 10-13.
[26]束洪春,司大军,葛耀中等.三角形环网输电线路故障测距新算法及其实现[J].电网技术, 2000, 24(4): 34-39.
[27] Djuric M B, Terzija V V. A new approach to the arcing faults detection for fast auto-reclosure in transmission systems [J]. Power Delivery, IEEE Transactions on, 1995, 10(4): 1793-1798.
[28] Djuric M B, Radojevic Z M, Terzija V V. Time domain solution of faults distance estimation and arcing faults detection on overhead lines [J]. Power Delivery, IEEE Transactions on, 1999, 14(1): 60-67.
[29] Wailar D L, Elangovan S, Liew A C. Fault impedance estimation algorithms for digital distance relaying [J]. Power Delivery, IEEE Transactions on, 1994, 9(3): 1375-1383.
[30]孙立山,陈学允.使用输电线路双端数据的故障测距研究[J].哈尔滨工业大学学报, 1999, 31(2): 58-60.
[31]陈铮,苏进喜,吴欣荣等.基于分布参数模型的高压输电线路故障测距算法[J].电网技术, 2000, 24(11): 31-33.
[32] Girgis A A, Hart D G, Peterson W L. A new fault location technique for two and three terminal lines [J]. Power Delivery, IEEE Transactions on, 1992, 7(1): 98-107.
[33] Girgis A A, Fallon C M. Fault location techniques for radial and loop transmission systems using digital fault recorded data [J]. Power Delivery, IEEE Transactions on, 1992, 7(4): 1936-1945.
[34]郭丽军.基于双端数据的高压输电线路故障测距新算法的研究[D].北京:华北电力大学, 2005.
[35]李骏,范春菊.基于小波分析的电缆-架空线混合输电线路行波故障测距方法[J].电网技术, 2006, 30(9): 92-97.
[36]陈宾,陈皓,刘伟.基于分布参数模型的混合输电线路故障测距和重合闸的研究[J].四川电力技术, 2010, 33(2): 42-44, 63.
[37]杨军,伍咏红,江文波.基于双端故障信息的高压电缆?架空线混合输电线路故障测距方法[J].电网技术, 2010, 34(1) :208-212.
[38]吴承恩,邰能灵,郁惟铺.超高压电缆-架空线混合输电线路故障测寻方法[J].电力系统自动化, 2005, 29(10): 26-30.
[39]乔幕新.架空线路的故障分析[J].中国科技纵横, 2010, (7): 125-125.
[40]蔡建伟.浅谈电力电缆产生故障的原因及对策[J].科技致富向导, 2010, 3(5): 95-98.
[41]刘伟,陈皓.基于分布参数模型的混合输电线路故障测距新算法[J].电力系统保护与控制, 2009, 37(24): 76-80.
[42]葛耀中.新型继电保护和故障测距的原理与技术[M].西安:西安交通大学出版社, 2007.
[43]唐信,陈兴洲.架空线弧垂观测检查及调整[J].中国科技信息, 2009, 8(17): 40-40, 47.
[44]冉波.用pspice对电力采集装置前置低通滤波器进行分析[J].西南民族大学学报(自然科学版), 2006, 32(5): 1058-1061.
[45]姚亮,胡再超,杭泱.常见傅氏变换的滤波性能分析[J].电力自动化设备, 2008, (1): 73-76.
[46]刘毅,温渤婴.差分与傅氏变换相结合算法在微机电流保护中的应用[J].继电器, 2000, 28(8): 36-38.
[47]黄飞腾,陈明军,郑慧.故障测距中的差分傅氏滤波改进算法[J].电力系统保护与控制, 2009, 37(11): 62-65.
[48]邓自立,马建为. MA模型参数估计的两段最小二乘法及其在自校正跟踪滤波器中的应用[J].科学技术与工程, 2003, 3(1): 3-5.
[49]苏文辉,李钢.一种能滤去衰减直流分量的改进全周傅氏算法[J].电力系统自动化, 2002, 26(23): 42-44.
[50]阎爱玲,杨新华.基于小波变换和相模变换的电力电缆故障测距[J].甘肃科学学报, 2009, 21(2): 141-143.
[51]张晓飞. GPS同步时钟技术在电力系统中的应用分析[J].广西电业, 2009, (4): 82-83, 78.
[52]王正林.精通MATLAB7 [M].北京:电子工业出版社, 2006.
[53]韩丽娜,杨志坚,李虎.电磁暂态程序EMTP在电力系统的应用[J].广东输电与变电技术, 2006, (2): 19-22.
[54]张艳秋,孟为民,陶磊.超高压输电线路自动重合闸技术分析[J].企业技术开发, 2010, 29(2): 20-21.
[55]李方永.自动重合闸在输电线路上的运用[J].中国高新技术企业, 2010, (16): 95-96.
[56]黄震,陈平.基于行波原理的110kV架空线-电缆混合输电线路自适应重合闸控制技术研究[J].四川电力技术, 2008, 31(B11): 1-3, 18.