地网接地电阻短距测量方法和降阻新技术研究
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摘要
发、变电站的接地系统是维护电力系统安全可靠运行，保障设备和人身安全的重要措施之一。接地电阻是发、变电站接地系统的重要技术指标。在发、变电站投运之前或运行一段时间后都要测量其接地电阻值。目前实用的接地电阻测量方法大都存在测量引线过长的弊端，过长的测试引线既不利于现场布线还会造成的强烈的电磁干扰，带来很大的测量误差。因此，对测量接地电阻的原理进行理论分析，尽量缩短测量接地电阻的电极引线，这对于保障电力系统的安全运行，减少工程人员的工作量和技术难度有着重要的学术意义和实际应用价值。同时，在地网面积有限，土壤电阻率较高等复杂情况下，如何经济、有效地减小接地电阻也成为电力系统十分关注的课题。
本论文从接地电阻的测量方法和降低接地电阻措施两个方面，深入探讨了短距测量接地电阻的原理、方法，以及新型空腹式接地装置的使用和设计方法。具体工作包括：
①从接地电阻的测量原理出发，讨论了采用短电流极引线测量地网接地电阻的可行性。使用GPC接地软件计算了各种接地体不同布置时地网外地面电位的变化，阐述了将不同布置情况的接地网等效为一以地网最大边长为直径的圆盘电极的理论。在计算中，本文合理考虑了水平接地体和垂直接地体的实际布置情况，建立了方形接地网和辅助电流极的计算等效模型。
②通过对模型的计算和讨论，发现在短距测量时，传统的0.618法将导致较大的测量误差，必须对测量结果进行修正，或者对测量位置进行调整。综合各种因素考虑，推荐在距离地网边缘距离为地网长边长度s的位置布置电流极，并在0.509s布置电压测量极，在满足工程精度要求的同时也极大的提高了测量效率。
③使用土壤分层理论来模拟地网所处土壤不均匀性，并根据土壤分层的不同，推导出了相应的短距测量位置计算公式，为在不均匀土壤测量接地电阻提供了参考。
④通过短距智能测量仪能将测量位置计算、变频技术、单片机技术、数字信号处理技术和现场测量数据有机的结合起来，充分利用人机交互与已有知识的优势，可以简单、准确地得到待测系统的接地电阻值。
⑤用理论研究和现场实验相结合的方法仔细探讨空腹式接地装置降低接地电阻的原理和使用方法。为空腹式接地装置在高土壤电阻率地区或地网面积较小的情况下的降阻提供科学的依据。
Grounding system of power plant and transformer substation is one of important parts of to keep reliable of the power system, ensure the safe of equipments and person. Grounding resistance is important technical parameter of grounding system. It needs to be measured accurately to ensure the grounding system to work during the system fault before system operation or after operation for some time. Today Electrode wire in measurement methods of grounding resistance is so long as to result in large influence and large amount of workload. It is great realistic significance that method with short electrode wire for grounding resistance measurement has been proposed. On the other hand, how to decrease the grounding resistance economically and effectively in a limited area with high soil resistivity becomes an important question of power system for discussion.
The paper studies the method of grounding resistance measurement and the new technology of decreasing the grounding resistance. The study includes the method and theory of resistance measurement with short electrode wire, the using and design method of kongfu grounding equipment.
(1)With the principle of measuring resistance, the paper carries through the theory analysis about possibility of measurement method with short electrode wire. By using GPC grogram, the paper calculates the variety of grounding potential with different placements of grounding rods. On the basis of calculations and analysis, the model of grounding grids and current-electrode are presented.
(2)The measurement error using the 0.618 method to measure grounding resistance with short electrode wire is discussed. The analysis results show that the measurement results must be modified, or change the placement of voltage-electrode. The paper recommends that the placement of voltage -electrode is 0.509s when the distance from the border of grounding grids to current-electrode is s that is the long border length of grids.
(3)The paper use two-layer theory to describe non-uniform soil. With the different two-layer soil model, some conclusions and formula that have great reference value are presented numerically.
(4)Considering the combination of the calculation of measuring placement, the digital signals processing technology, the frequency-changing technology, the single chip
computer technology and the measurement data of fieldwork, the measuring brainpower apparatus can largely make use of the man-machine conversation technology and measuring knowledge. By using this apparatus, the errors between the measured results and real grounding resistance can be eliminated largely.
(5)With the research of theory and the analysis of field data, principle and method using kongfu grounding equipment to decrease the grounding resistance were studied. The paper provides scientific method and explains for decreasing grounding resistance in a limited, high soil resistivity area by using kongfu grounding equipment.
本论文从接地电阻的测量方法和降低接地电阻措施两个方面，深入探讨了短距测量接地电阻的原理、方法，以及新型空腹式接地装置的使用和设计方法。具体工作包括：
①从接地电阻的测量原理出发，讨论了采用短电流极引线测量地网接地电阻的可行性。使用GPC接地软件计算了各种接地体不同布置时地网外地面电位的变化，阐述了将不同布置情况的接地网等效为一以地网最大边长为直径的圆盘电极的理论。在计算中，本文合理考虑了水平接地体和垂直接地体的实际布置情况，建立了方形接地网和辅助电流极的计算等效模型。
②通过对模型的计算和讨论，发现在短距测量时，传统的0.618法将导致较大的测量误差，必须对测量结果进行修正，或者对测量位置进行调整。综合各种因素考虑，推荐在距离地网边缘距离为地网长边长度s的位置布置电流极，并在0.509s布置电压测量极，在满足工程精度要求的同时也极大的提高了测量效率。
③使用土壤分层理论来模拟地网所处土壤不均匀性，并根据土壤分层的不同，推导出了相应的短距测量位置计算公式，为在不均匀土壤测量接地电阻提供了参考。
④通过短距智能测量仪能将测量位置计算、变频技术、单片机技术、数字信号处理技术和现场测量数据有机的结合起来，充分利用人机交互与已有知识的优势，可以简单、准确地得到待测系统的接地电阻值。
⑤用理论研究和现场实验相结合的方法仔细探讨空腹式接地装置降低接地电阻的原理和使用方法。为空腹式接地装置在高土壤电阻率地区或地网面积较小的情况下的降阻提供科学的依据。
Grounding system of power plant and transformer substation is one of important parts of to keep reliable of the power system, ensure the safe of equipments and person. Grounding resistance is important technical parameter of grounding system. It needs to be measured accurately to ensure the grounding system to work during the system fault before system operation or after operation for some time. Today Electrode wire in measurement methods of grounding resistance is so long as to result in large influence and large amount of workload. It is great realistic significance that method with short electrode wire for grounding resistance measurement has been proposed. On the other hand, how to decrease the grounding resistance economically and effectively in a limited area with high soil resistivity becomes an important question of power system for discussion.
The paper studies the method of grounding resistance measurement and the new technology of decreasing the grounding resistance. The study includes the method and theory of resistance measurement with short electrode wire, the using and design method of kongfu grounding equipment.
(1)With the principle of measuring resistance, the paper carries through the theory analysis about possibility of measurement method with short electrode wire. By using GPC grogram, the paper calculates the variety of grounding potential with different placements of grounding rods. On the basis of calculations and analysis, the model of grounding grids and current-electrode are presented.
(2)The measurement error using the 0.618 method to measure grounding resistance with short electrode wire is discussed. The analysis results show that the measurement results must be modified, or change the placement of voltage-electrode. The paper recommends that the placement of voltage -electrode is 0.509s when the distance from the border of grounding grids to current-electrode is s that is the long border length of grids.
(3)The paper use two-layer theory to describe non-uniform soil. With the different two-layer soil model, some conclusions and formula that have great reference value are presented numerically.
(4)Considering the combination of the calculation of measuring placement, the digital signals processing technology, the frequency-changing technology, the single chip
computer technology and the measurement data of fieldwork, the measuring brainpower apparatus can largely make use of the man-machine conversation technology and measuring knowledge. By using this apparatus, the errors between the measured results and real grounding resistance can be eliminated largely.
(5)With the research of theory and the analysis of field data, principle and method using kongfu grounding equipment to decrease the grounding resistance were studied. The paper provides scientific method and explains for decreasing grounding resistance in a limited, high soil resistivity area by using kongfu grounding equipment.
引文
[1] 曾永林，接地技术，北京，水利电力出版社，1978
[2] 解广润，电力系统接地技术，北京，水力电力出版社，1991
[3] Zupa F P, Laidig J F,A Practical Ground Potential Rise Prediction Technique for Power Station,IEEE T-PA S, 1980,Vol.99,No. 2:207-216
[4] Sobral S T, Horta S J J, Mukhedkar D.,A Proposal for Ground Measurement Techniques in Substations Fed Exclusively by Power Cable,IEEE T-PWRD, 1988,Vol.3,No.4:1403-1409
[5] 中华人民共和国电力行业标准DL／T 621—1997,交流电气装置的接地，北京，中国电力出版社，1998
[6] Dawalibi F, Mukhedkar D,Resistance Measurement of Large Grounding Systems. IEEE T-PWRD, 1979,Vol.9,No.6:2348～2354
[7] 邓华，关于接地装置测试的探讨，云南电力技术，1999，Vol．27，No．2：12
[8] 刘宝成，电压电流法，检测接地网技术研究，1999，No．2：7
[9] 陈立辉，接地电阻的确定，计量与测试技术，1997，No．6：22
[10] 李汝彪，接地电阻测量的四极法固有误差估计，浙江电力，1994，No．4：10-12
[11] 姚金霞，常景荣，大型地网接地电阻测量中的几个问题，山东电力技术，1997，No．2：15
[12] 梁建伟，500kV变电站接地装置的测试．山西电力技术，1994，Vol．14，No．1：60-62
[13] 鲁志伟，孟奇，王印宏，接地电阻测量的修正系数法，东北电力技术，1997，No．10：6
[14] 李茂堂，基于白噪音的接地电阻测量原理与误差分析，电网技术，1996，Vol．20，No．10：41-43
[15] 李茂堂，刘月生，王新中，基于功率谱和高阶谱的接地电阻测量方法研究，电子测量与仪器学报，1998．Vol．12，No．3：7-12
[16] 王洪新，关根志等，一种测量接地网工频接地电阻的新方法，武汉水利电力大学学报，1998，Vol．31，No．3：48-51
[17] 曹梅月，变电站地网技术的发展综述，中国电力，1997，Vol．30，No．7：14-16
[18] 姚金霞，孙为民，短电流极引线测量接地电阻的研究，山东电力技术，2001，No．2：5-7
[19] 曾嵘，高土壤电阻地区发变电站接地技术研究，清华大学博士学位论文，1999
[20] Baldev, Thapar, Victor Gerez,Arun Balakriahnan,Evaluation of Ground Resistance of a Grounding Grid of Any Shape,IEEE Transaction on power Delivery, 1991,Vol.7,No.6:202-209
[21] A.P.Meliopoulos,M.GMoharam,Transient Analysis of Grounding Systems,.IEEE Transactions on power Apparatus and System, 1983,Vol. 12,No.2:102-111
[22] 王洪泽，关于等间距与不等间距均压接地网的接地电阻问题，广西水利水电，1994，No．2：61-64
[23] L.Huang,X.Chen,H.Yan,Study of Unequally Spaced Grounding Grids,IEEE Transactions on
Power Delivery, 1995,Vol. 10,No.2:154-158
[24] 陈先禄，刘黎等，用垂直接地极降低地网接地电阻的若干问题，电工技术杂志，2002，No．11：56-58
[25] 应順潮，接地电阻测量中测量极位置的确定，高电压技术，1992，No．1：80-83
[26] 戴武昌，刘永德，常树生，接地电阻测量中心的偏差对测量结果的影响，东北电力学院，1997，Vol．17．No．1：104-106
[27] J.Ma, F.P.Dawalibi, Effects of Inductive Coupling Between Leads in Grounding Iimpedance Measurement Resistance Using Fall-of potential Method, IEEET-PD, 1999, Vol. 11, No. 16: 266-271
[28] 赵智，吴希，接地电阻测量方法的改进，继电器，2001，Vol．29，No．5：30-33
[29] 罗卓林，桂腊贵，非均匀土壤接地电阻测量方法的探讨，高电压技术，1981，No．4：25-49
[30] J.L.del ,Alamo Ph.D ,Second Order Gradient Technique for Estimation of Soil Parameters in a Two-Layer Earth,IEEE Transactions on Power Delivery, 1991 ,Vol.6,No.3:1166-1170
[31] 鲁志伟，双层土壤中接地电阻的测量，电网技术，1998，Vol．22，No．5：57-59
[32] 张波，白永胜，杨杰等，对补偿法2层土壤中接地网接地电阻的修正，高电压技术，2001，Vol．27，No．3：31-34
[33] 鲁志伟，史艳玲，文习山，垂直分层土壤中接地电阻的测量极其误差分析，高电压技术，2001，No．3：36-39
[34] 潘文霞，邹鹰，双层土壤参数的优化计算，中国电机工程学报，1996，Vol．16，No．5：34-36
[35] Y. L.Chow, J.J.Yang, Grounding Resistance of Buried Electrodes in Multi-Layer Earth Predicted by Simple Voltage Measurements along Earth Surface-A Theoretical Discussion, IEEET-PD, 1995, Vol. 10,No.2:707-713
[36] Zhu Xi,Cen Xian Lu,,Han Zheng Dong,A New Type of Digital Computer System on Impulse Voltage Opto-electronic Measurement, 1989,Vol.28,No.8:164-168
[37] 周文俊，文习山等，有效消除地网干扰的接地电阻变频测量法，高电压技术,1998，Vol．24，No．3：51-53
[38] C.wang, T.Takasima, T.Sakuta, Grounding Resistance Measurement Using Fall-of potential Method with Potential Probe Located in Opposite Direction to The Current Probe, IEEET-PD, 1998, Vol.13,No. 10:1128-1135
[39] Jinxi Ma, Farid P.Dawalibi, Extended Analysis of Ground Impedance Measurement Using the Fall-of-Potential Method, IEEE T-PD,2001, Vol. 17,No.4:881-885
[2] 解广润，电力系统接地技术，北京，水力电力出版社，1991
[3] Zupa F P, Laidig J F,A Practical Ground Potential Rise Prediction Technique for Power Station,IEEE T-PA S, 1980,Vol.99,No. 2:207-216
[4] Sobral S T, Horta S J J, Mukhedkar D.,A Proposal for Ground Measurement Techniques in Substations Fed Exclusively by Power Cable,IEEE T-PWRD, 1988,Vol.3,No.4:1403-1409
[5] 中华人民共和国电力行业标准DL／T 621—1997,交流电气装置的接地，北京，中国电力出版社，1998
[6] Dawalibi F, Mukhedkar D,Resistance Measurement of Large Grounding Systems. IEEE T-PWRD, 1979,Vol.9,No.6:2348～2354
[7] 邓华，关于接地装置测试的探讨，云南电力技术，1999，Vol．27，No．2：12
[8] 刘宝成，电压电流法，检测接地网技术研究，1999，No．2：7
[9] 陈立辉，接地电阻的确定，计量与测试技术，1997，No．6：22
[10] 李汝彪，接地电阻测量的四极法固有误差估计，浙江电力，1994，No．4：10-12
[11] 姚金霞，常景荣，大型地网接地电阻测量中的几个问题，山东电力技术，1997，No．2：15
[12] 梁建伟，500kV变电站接地装置的测试．山西电力技术，1994，Vol．14，No．1：60-62
[13] 鲁志伟，孟奇，王印宏，接地电阻测量的修正系数法，东北电力技术，1997，No．10：6
[14] 李茂堂，基于白噪音的接地电阻测量原理与误差分析，电网技术，1996，Vol．20，No．10：41-43
[15] 李茂堂，刘月生，王新中，基于功率谱和高阶谱的接地电阻测量方法研究，电子测量与仪器学报，1998．Vol．12，No．3：7-12
[16] 王洪新，关根志等，一种测量接地网工频接地电阻的新方法，武汉水利电力大学学报，1998，Vol．31，No．3：48-51
[17] 曹梅月，变电站地网技术的发展综述，中国电力，1997，Vol．30，No．7：14-16
[18] 姚金霞，孙为民，短电流极引线测量接地电阻的研究，山东电力技术，2001，No．2：5-7
[19] 曾嵘，高土壤电阻地区发变电站接地技术研究，清华大学博士学位论文，1999
[20] Baldev, Thapar, Victor Gerez,Arun Balakriahnan,Evaluation of Ground Resistance of a Grounding Grid of Any Shape,IEEE Transaction on power Delivery, 1991,Vol.7,No.6:202-209
[21] A.P.Meliopoulos,M.GMoharam,Transient Analysis of Grounding Systems,.IEEE Transactions on power Apparatus and System, 1983,Vol. 12,No.2:102-111
[22] 王洪泽，关于等间距与不等间距均压接地网的接地电阻问题，广西水利水电，1994，No．2：61-64
[23] L.Huang,X.Chen,H.Yan,Study of Unequally Spaced Grounding Grids,IEEE Transactions on
Power Delivery, 1995,Vol. 10,No.2:154-158
[24] 陈先禄，刘黎等，用垂直接地极降低地网接地电阻的若干问题，电工技术杂志，2002，No．11：56-58
[25] 应順潮，接地电阻测量中测量极位置的确定，高电压技术，1992，No．1：80-83
[26] 戴武昌，刘永德，常树生，接地电阻测量中心的偏差对测量结果的影响，东北电力学院，1997，Vol．17．No．1：104-106
[27] J.Ma, F.P.Dawalibi, Effects of Inductive Coupling Between Leads in Grounding Iimpedance Measurement Resistance Using Fall-of potential Method, IEEET-PD, 1999, Vol. 11, No. 16: 266-271
[28] 赵智，吴希，接地电阻测量方法的改进，继电器，2001，Vol．29，No．5：30-33
[29] 罗卓林，桂腊贵，非均匀土壤接地电阻测量方法的探讨，高电压技术，1981，No．4：25-49
[30] J.L.del ,Alamo Ph.D ,Second Order Gradient Technique for Estimation of Soil Parameters in a Two-Layer Earth,IEEE Transactions on Power Delivery, 1991 ,Vol.6,No.3:1166-1170
[31] 鲁志伟，双层土壤中接地电阻的测量，电网技术，1998，Vol．22，No．5：57-59
[32] 张波，白永胜，杨杰等，对补偿法2层土壤中接地网接地电阻的修正，高电压技术，2001，Vol．27，No．3：31-34
[33] 鲁志伟，史艳玲，文习山，垂直分层土壤中接地电阻的测量极其误差分析，高电压技术，2001，No．3：36-39
[34] 潘文霞，邹鹰，双层土壤参数的优化计算，中国电机工程学报，1996，Vol．16，No．5：34-36
[35] Y. L.Chow, J.J.Yang, Grounding Resistance of Buried Electrodes in Multi-Layer Earth Predicted by Simple Voltage Measurements along Earth Surface-A Theoretical Discussion, IEEET-PD, 1995, Vol. 10,No.2:707-713
[36] Zhu Xi,Cen Xian Lu,,Han Zheng Dong,A New Type of Digital Computer System on Impulse Voltage Opto-electronic Measurement, 1989,Vol.28,No.8:164-168
[37] 周文俊，文习山等，有效消除地网干扰的接地电阻变频测量法，高电压技术,1998，Vol．24，No．3：51-53
[38] C.wang, T.Takasima, T.Sakuta, Grounding Resistance Measurement Using Fall-of potential Method with Potential Probe Located in Opposite Direction to The Current Probe, IEEET-PD, 1998, Vol.13,No. 10:1128-1135
[39] Jinxi Ma, Farid P.Dawalibi, Extended Analysis of Ground Impedance Measurement Using the Fall-of-Potential Method, IEEE T-PD,2001, Vol. 17,No.4:881-885