CN103217612A - Fault on-line monitoring and real-time distance measurement method for armored power cable - Google Patents
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Abstract
本发明公开了一种铠装电力电缆故障在线监测与实时测距的方法。本发明利用电缆铠装层与大地形成的回路进行电缆故障测距，由于测距系统与高压电缆的芯线之间没有直接的电气连接，不仅安全可靠，而且在工作时完全不影响电缆的正常输电任务。本发明通过利用电缆的铠装层与大地形成的回路，以及小波分析技术进行电缆故障点的测距，可同时实现电缆故障的在线监测和实时测距的双重功能，简化了设备复杂度和操作复杂度，提高了故障检测和测距效率，解决了电力电缆故障普遍缺乏有效的在线监测与实时测距手段的技术难点问题，通过将故障检测和故障测距合二为一，不仅降低了设备复杂度和成本，而且也减少了操作复杂度，提高了故障检测和测距效率。
The invention discloses a method for on-line fault monitoring and real-time distance measurement of an armored power cable. The present invention uses the loop formed by the cable armor layer and the earth to measure cable faults. Since there is no direct electrical connection between the ranging system and the core wire of the high-voltage cable, it is not only safe and reliable, but also does not affect the normal operation of the cable at all during operation. Power transmission task. The invention uses the loop formed by the armored layer of the cable and the ground, and the wavelet analysis technology to measure the distance of the cable fault point, and can realize the dual functions of online monitoring and real-time distance measurement of the cable fault at the same time, simplifying the equipment complexity and operation The complexity improves the efficiency of fault detection and distance measurement, and solves the technical difficulties of lack of effective online monitoring and real-time distance measurement methods for power cable faults. By combining fault detection and fault distance measurement, it not only reduces equipment Complexity and cost, but also reduce operational complexity, improve fault detection and ranging efficiency.
Description
技术领域technical field
本发明涉及电力电缆故障的检测方法，具体涉及一种铠装电力电缆故障在线监测与实时测距的方法。The invention relates to a detection method for a power cable fault, in particular to a method for on-line monitoring and real-time distance measurement of an armored power cable fault.
背景技术Background technique
随着城市建设的发展，配网线路的敷设方式逐步由裸线架空型过渡到电缆地下暗敷设。比较架空线路和地下电缆线路，二者在故障测距方面虽有相通之处，但也存在明显的不同。尤其是地下电缆多用于中低压输电，长度相对较短，且其故障不可观测，如果故障测距结果相差数百米，那么就已失去了测距的价值；而且，地下电缆故障检修困难，如果故障测距不准确，将会造成大量的人力、物力和财力浪费。因此，地下电缆线路测距需要有更为精确的测距方法。With the development of urban construction, the laying method of distribution network lines gradually transitions from the bare wire overhead type to the underground cable laying. Comparing overhead lines and underground cable lines, although the two have similarities in fault location, there are also obvious differences. In particular, underground cables are mostly used for medium and low-voltage power transmission, and their lengths are relatively short, and their faults cannot be observed. If the results of fault distance measurement differ by hundreds of meters, the value of distance measurement has been lost; moreover, underground cables are difficult to repair. Inaccurate fault location will cause a lot of waste of manpower, material resources and financial resources. Therefore, a more accurate ranging method is needed for underground cable line ranging.
从技术角度来讲，目前人们采用和研究的电缆故障测距方法主要是离线测距，即在发生电缆故障以后，采取先断电再测距的方法。这样就要求电力使用部门必需同时拥有电力电缆故障的实时监测及事后测距两套独立系统，从一定程度上增加了故障测距成本和复杂度。此外，从故障测距的原理方法上，目前普遍采用电缆芯线回路，即由电缆芯线构成的各种电路回路，如芯线与屏蔽层构成的电路回路及芯线间构成的电路回路等，然后借助不同的测距方法，比如电桥法或行波法等，以识别和测量电缆故障。由于电缆芯线主要担负高压输电任务，其输电电压与故障测距所要求的信号电压很难一致，因此利用芯线回路进行故障测距较难与芯线输电同时进行，不能实现在线测距。From a technical point of view, the cable fault location method adopted and researched by people at present is mainly offline distance measurement, that is, after a cable fault occurs, the method of first power off and then distance measurement is adopted. This requires the power user department to have two independent systems for real-time monitoring of power cable faults and post-event distance measurement, which increases the cost and complexity of fault distance measurement to a certain extent. In addition, from the principle and method of fault location, cable core loops are generally used at present, that is, various circuit loops composed of cable core wires, such as circuit loops composed of core wires and shielding layers and circuit loops between core wires, etc. , and then with the help of different ranging methods, such as the bridge method or traveling wave method, etc., to identify and measure cable faults. Since the cable core wire is mainly responsible for high-voltage power transmission, its transmission voltage is difficult to be consistent with the signal voltage required for fault location. Therefore, it is difficult to use the core wire loop for fault location measurement and core wire transmission at the same time, and online distance measurement cannot be realized.
由以上分析可知，由于目前正在使用的各种电缆故障测距主要基于电缆芯线回路，因此只能采取离线测距的方法，不能实现在线实时测距；而且，离线测距还会带来故障监测与故障测距分离，需要同时建设两套独立系统的问题。因此，在电力电缆故障测距领域亟需开展能同时完成电缆故障的在线监测和实时测距的方法和技术研究。From the above analysis, it can be seen that since the fault location of various cables currently in use is mainly based on the cable core wire loop, only the method of offline distance measurement can be adopted, and online real-time distance measurement cannot be realized; moreover, offline distance measurement will also bring faults. The separation of monitoring and fault distance measurement requires the construction of two independent systems at the same time. Therefore, in the field of power cable fault location, it is urgent to carry out research on methods and technologies that can simultaneously complete online monitoring and real-time location of cable faults.
发明内容Contents of the invention
针对以上现有技术中存在的问题，本发明通过对现有电力电缆故障测距方法的优缺点以及测距原理的深入研究，提出了一种利用铠装电力电缆的铠装层与大地之间形成的回路，以及小波分析技术进行电力电缆故障在线监测和实时测距的新方法，可广泛用于电缆防盗和线路检修等领域。目前国内外尚未见到与该发明方法类似的研究和应用报道，因此本发明具有重要的理论和实际应用价值。Aiming at the problems existing in the above prior art, the present invention proposes a method that utilizes the distance between the armored layer of the armored power cable and the ground through in-depth research on the advantages and disadvantages of the existing power cable fault location method and the principle of distance measurement. The formed circuit and the new method of online monitoring and real-time distance measurement of power cable faults by wavelet analysis technology can be widely used in the fields of cable anti-theft and line maintenance. At present, no research and application reports similar to the inventive method have been seen at home and abroad, so the present invention has important theoretical and practical application values.
本发明的目的是提供一种铠装电力电缆故障在线监测与测距的方法，用于解决目前电力电缆故障缺乏有效的在线监测与实时测距的技术手段的问题。The purpose of the present invention is to provide a method for on-line monitoring and ranging of armored power cable faults, which is used to solve the problem that current power cable faults lack effective online monitoring and real-time ranging technical means.
本发明在电缆测量端的铠装层和大地之间施加和发射行波脉冲信号，行波脉冲信号在由铠装层和大地之间形成的行波传输系统中沿着电缆方向传播，在电缆的另一端的铠装层和大地之间设置匹配负载，匹配负载与行波传输系统的特征阻抗匹配，从而在铠装层与大地之间形成回路。The present invention applies and transmits a traveling wave pulse signal between the armored layer of the cable measuring end and the earth, and the traveling wave pulse signal propagates along the direction of the cable in the traveling wave transmission system formed between the armored layer and the earth. A matching load is set between the armor layer and the ground at the other end, and the matching load matches the characteristic impedance of the traveling wave transmission system, thereby forming a loop between the armor layer and the ground.
本发明的一种铠装电力电缆故障在线监测与测距的方法，包括以下步骤：A method for on-line fault monitoring and ranging of an armored power cable of the present invention comprises the following steps:
1)在电缆的测量端的铠装层与大地之间施加和发射低压的发射行波脉冲信号，并记录发射行波脉冲信号的波形和时间；1) Apply and launch a low-voltage traveling wave pulse signal between the armored layer of the measuring end of the cable and the earth, and record the waveform and time of the traveling wave pulse signal;
2)根据电缆的测量端收到的反射行波信号，判断有无电缆故障，如果有故障则进入步骤3)，如果没有故障则返回步骤1)；2) According to the reflected traveling wave signal received by the measuring end of the cable, judge whether there is a cable fault, if there is a fault, then enter step 3), if there is no fault, then return to step 1);
3)利用小波分析技术对反射行波信号进行消噪处理和检测分析，获得反射行波信号到达测量端的准确时间；3) Use wavelet analysis technology to perform noise reduction processing and detection analysis on the reflected traveling wave signal, and obtain the accurate time when the reflected traveling wave signal reaches the measurement end;
4)根据测量端得到的发射行波脉冲信号与反射行波信号间的时间差，以及行波传播速度，计算故障点的准确位置。4) Calculate the exact location of the fault point according to the time difference between the transmitted traveling wave pulse signal and the reflected traveling wave signal obtained at the measuring end, and the propagation speed of the traveling wave.
本发明主要针对的电缆故障类型是电缆开路及断路故障，这类故障在芯线和铠装层中同时发生，因此能够通过检测铠装层得到整个电缆的状态。本发明基于行波法测距的基本原理，其中，在步骤1)中，在电缆的测量端的铠装层与大地之间连续不断地施加和发射低压行波脉冲信号，并记录测量端发射的行波信号波形以及发射时间；在步骤2)中，主要根据测量端是否收到反射行波信号判定是否发生电缆故障；在步骤3)中对有故障情况下测量端收到的反射行波信号利用小波分析技术进行信号处理，从而获得反射行波信号到达测量端的准确时间；在步骤4)中，先计算测量端发射的行波信号与接收到的反射行波信号间的时间差；然后与行波传播速度相乘得到距离，最后将该距离除以二即可获得故障点的准确位置。The types of cable faults that the present invention is mainly aimed at are cable open circuit and open circuit faults, which occur simultaneously in the core wire and the armor layer, so the state of the entire cable can be obtained by detecting the armor layer. The present invention is based on the basic principle of traveling wave distance measurement, wherein, in step 1), the low-voltage traveling wave pulse signal is continuously applied and emitted between the armored layer of the measuring end of the cable and the earth, and the pulse signal emitted by the measuring end is recorded. Traveling wave signal waveform and launch time; in step 2), it is mainly determined whether a cable fault occurs based on whether the measuring end receives the reflected traveling wave signal; in step 3) the reflected traveling wave signal received by the measuring end under the fault condition Utilize wavelet analysis technology to carry out signal processing, thus obtain the accurate time that reflected traveling wave signal arrives at measuring terminal; The wave propagation speed is multiplied to obtain the distance, and finally the distance is divided by two to obtain the exact location of the fault point.
在步骤1)中，发射脉冲的时间宽度和前后脉冲间的时间间隔主要由故障点距离来定。如果时间参数设计不合理造成反射脉冲与发射脉冲重迭，便无法区分出来，此时将不能测出故障点的距离，出现盲区；发送脉冲愈宽，测量盲区愈大。但是，设计发射脉冲的时间参数还需兼顾反射脉冲的检测难度问题。从减小盲区的角度来看，发射脉冲窄一些好，但脉冲愈窄，它所包含的高频分量愈丰富，因而线路高频损耗大，反射脉冲幅值小，畸变更严重，这将影响后续的反射信号检测效果和故障测距精度。为了解决这一问题，本发明将发射行波脉冲信号的宽度分为若干个范围，根据测量距离来选择脉冲宽度，测量距离愈远，脉冲宽度愈宽，测量距离愈短，脉冲宽度愈窄。In step 1), the time width of the transmitted pulse and the time interval between the preceding and following pulses are mainly determined by the distance from the fault point. If the time parameter design is unreasonable and causes the reflected pulse and the transmitted pulse to overlap, they cannot be distinguished. At this time, the distance to the fault point cannot be measured, and a blind zone appears; the wider the transmitted pulse, the larger the measurement blind zone. However, the design of the time parameters of the transmitted pulse also needs to take into account the difficulty of detecting the reflected pulse. From the perspective of reducing the blind area, it is better to have a narrower transmitted pulse, but the narrower the pulse, the richer the high-frequency components it contains, so the high-frequency loss of the line is large, the amplitude of the reflected pulse is small, and the distortion is more serious, which will affect Subsequent reflection signal detection effect and fault location accuracy. In order to solve this problem, the present invention divides the width of the transmitted traveling wave pulse signal into several ranges, and selects the pulse width according to the measurement distance. The farther the measurement distance is, the wider the pulse width is, and the shorter the measurement distance is, the narrower the pulse width is.
在步骤2)中，当测量端的发射行波脉冲信号遇到阻抗不匹配点的故障点(如电缆的短路或断路)时会发生反射，在测量端会收到相关的反射行波信号，则需要在测量端记录收到的反射行波信号，进入步骤3)。而当电缆没有发生故障时，此时由于被测电缆的另一端设置有匹配负载，处于阻抗匹配状态，所以在测量端不会收到相关的反射行波信号。因此，可以通过不断检测测量端是否收到反射行波信号来判断是否出现电缆故障，从而实现电缆故障的在线监测。In step 2), when the transmitted traveling wave pulse signal at the measuring end meets the fault point of the impedance mismatch point (such as a short circuit or open circuit of the cable), reflection will occur, and the relevant reflected traveling wave signal will be received at the measuring end, then It is necessary to record the received reflected traveling wave signal at the measurement end, go to step 3). When the cable is not faulty, the other end of the cable under test is equipped with a matching load and is in an impedance matching state, so the relevant reflected traveling wave signal will not be received at the measurement end. Therefore, it is possible to judge whether there is a cable fault by continuously detecting whether the measuring end receives the reflected traveling wave signal, thereby realizing on-line monitoring of the cable fault.
在步骤3)中，小波分析技术主要用于对测量端接收到的反射行波信号进行特征分析，从而获得反射信号的准确起始时间，以提高故障测距精度。其主要方法是：采用求解小波变换模极大值的方法检测反射行波信号中的奇异点，作为反射行波信号到达测量端的起始时刻点。In step 3), the wavelet analysis technology is mainly used to analyze the characteristics of the reflected traveling wave signal received by the measuring end, so as to obtain the accurate starting time of the reflected signal, so as to improve the accuracy of fault location. The main method is: use the method of solving the modulus maximum value of wavelet transform to detect the singular point in the reflected traveling wave signal, and use it as the initial time point when the reflected traveling wave signal arrives at the measuring end.
利用小波分析技术对反射行波信号进行特征分析的主要过程如下：a)对反射行波信号进行小波变换，求取各尺度下的模极大值；b)在低频高尺度下考察保留下的模极大值，寻找反射行波信号的波头最大值出现的位置T1，该时刻为行波波头到达的大致时刻；c)在确定初始波头到达时刻的尺度下考察模极大值的分布，在初始波头到达后的范围内进行搜索，采用小波方法确定反射行波信号相应的模极大值的位置，即为反射行波信号到达测量端的准确时间，其中，l是电缆线路总长度，v是行波传播速度。The main process of using wavelet analysis technology to analyze the characteristics of the reflected traveling wave signal is as follows: a) Perform wavelet transform on the reflected traveling wave signal to obtain the modulus maxima at each scale; Modulus maxima, find the position T 1 where the maximum value of the wave head of the reflected traveling wave signal appears, and this moment is the approximate time when the wave head of the traveling wave arrives; c) Investigate the distribution of the modulus maximum value under the scale of determining the arrival time of the initial wave head , after the initial wave head arrives at Search within the range, and use the wavelet method to determine the position of the corresponding modulus maximum of the reflected traveling wave signal, which is the exact time when the reflected traveling wave signal reaches the measurement end, where l is the total length of the cable line, and v is the propagation speed of the traveling wave.
本发明利用电缆铠装层与大地形成的回路进行电缆故障测距，从而同时实现了电缆故障在线监测和实时测距的双重功能。由于测距系统与高压电缆的芯线之间没有直接的电气连接，不仅安全可靠，而且在工作时完全不影响电缆的正常输电任务，因此可以在电缆输电的同时实现电缆故障的在线监测和实时测距。本发明通过将故障检测和故障测距合二为一，不仅降低了设备复杂度和成本，而且也减少了操作复杂度，提高了故障检测和测距效率。The invention utilizes the loop formed by the cable armor layer and the ground to measure the distance of the cable fault, thereby simultaneously realizing the dual functions of on-line monitoring of the cable fault and real-time distance measurement. Since there is no direct electrical connection between the ranging system and the core wire of the high-voltage cable, it is not only safe and reliable, but also does not affect the normal power transmission task of the cable at all during work, so the online monitoring and real-time monitoring of cable faults can be realized while the cable is transmitting power. ranging. The invention not only reduces equipment complexity and cost, but also reduces operation complexity by combining fault detection and fault distance measurement, and improves the efficiency of fault detection and distance measurement.
此外，本发明利用小波分析技术分析获取反射行波脉冲信号的准确到达时间，提高故障测距精度。准确标定故障反射信号的行波波头到达时刻是保证和提高测距精度的关键。需要考虑两方面的主要因素：一是行波频散问题。行波脉冲信号中含有丰富的频率分量，且每一种频率分量的传播速度和衰减常数都不相同，因此会导致行波脉冲信号在传输过程中波形发生变形，具体表现为行波波头部分具有一定的上升时间。传统的脉冲检测方法主要是通过比较脉冲信号是否越过门槛值实现检测，其判断力和抗干扰能力差，难以精确地确定反射行波波头前沿到达的时刻。二是传输过程引入的噪声问题。传统消噪方法普遍只适用于信号平稳且具有明显区别于噪声频谱特征的情况，但由于电缆故障测距信号是含有大量高频分量的非平稳信号，因此如果采用传统的消噪方法效果将不是很理想。由于小波分析技术是一种可以自适应地从时频域同时进行信号局部化分析，并且能够聚焦到信号时域和频域任意细节的分析方法。因此，本发明利用小波分析技术，对反射行波信号在不同尺度下进行干扰分析和抑制，通过小波变换模极大值及奇异性检测原理可以检测获得反射行波信号的准确到达时间。In addition, the present invention uses wavelet analysis technology to analyze and obtain the accurate arrival time of the reflected traveling wave pulse signal, thereby improving the accuracy of fault distance measurement. Accurate calibration of the arrival time of the traveling wave head of the fault reflection signal is the key to ensure and improve the ranging accuracy. Two main factors need to be considered: one is the dispersion of traveling waves. The traveling wave pulse signal contains abundant frequency components, and the propagation speed and attenuation constant of each frequency component are different, so the waveform of the traveling wave pulse signal will be deformed during the transmission process. rise time. The traditional pulse detection method mainly realizes the detection by comparing whether the pulse signal crosses the threshold, which has poor judgment and anti-interference ability, and it is difficult to accurately determine the moment when the front edge of the reflected traveling wave arrives. The second is the noise problem introduced by the transmission process. The traditional denoising method is generally only suitable for the situation where the signal is stable and has obvious spectral characteristics different from the noise. However, since the cable fault ranging signal is a non-stationary signal containing a large number of high-frequency components, if the traditional denoising method is used, the effect will not be Ideal. The wavelet analysis technology is an analysis method that can adaptively analyze signal localization simultaneously from the time-frequency domain, and can focus on arbitrary details of the signal time domain and frequency domain. Therefore, the present invention utilizes wavelet analysis technology to perform interference analysis and suppression on reflected traveling wave signals at different scales, and the accurate arrival time of reflected traveling wave signals can be detected through wavelet transform modulus maxima and singularity detection principles.
本发明的有益效果：Beneficial effects of the present invention:
本发明通过利用电缆的铠装层与大地形成的回路，以及小波分析技术进行电缆故障点的测距，可同时实现电缆故障的在线监测和实时测距的双重功能，简化了设备复杂度和操作复杂度，提高了故障检测和测距效率，解决了电力电缆故障普遍缺乏有效的在线监测与实时测距手段的技术难点问题。The invention uses the loop formed by the armored layer of the cable and the ground, and the wavelet analysis technology to measure the distance of the cable fault point, and can realize the dual functions of online monitoring and real-time distance measurement of the cable fault at the same time, simplifying the equipment complexity and operation The complexity improves the efficiency of fault detection and distance measurement, and solves the technical difficulties of the general lack of effective online monitoring and real-time distance measurement methods for power cable faults.
附图说明Description of drawings
图1为本发明的铠装电力电缆故障在线监测与实时测距的方法的原理示意图；Fig. 1 is the principle schematic diagram of the method for armored power cable fault on-line monitoring and real-time ranging of the present invention;
图2为本发明的铠装电力电缆故障在线监测与实时测距的方法的流程图。Fig. 2 is a flow chart of the method for on-line fault monitoring and real-time distance measurement of armored power cables according to the present invention.
具体实施方式Detailed ways
下面结合附图，通过实施例详细描述本发明。The present invention will be described in detail below through embodiments in conjunction with the accompanying drawings.
如图1所示，在电缆的测量端A的铠装层4和大地之间施加和发射行波脉冲信号s，行波脉冲信号在铠装层4和大地之间形成的行波传输系统中沿着电缆的方向传播，在电缆另一端B的铠装层与大地之间设置匹配负载R，匹配负载与行波传输系统的特征阻抗匹配，从而铠装层与大地之间形成回路。当发射行波脉冲信号s遇到电缆的故障点P时，反射行波信号r沿反方向传输至测量端A。其中，电缆包括外护套1、绝缘层2、芯线3及铠装层4。As shown in Figure 1, a traveling wave pulse signal s is applied and emitted between the
1)在电缆测量端的铠装层与大地之间施加和发射低压的发射行波脉冲信号，并记录发射行波脉冲信号的波形和时间。1) Apply and transmit a low-voltage transmitted traveling wave pulse signal between the armored layer of the cable measuring end and the earth, and record the waveform and time of the transmitted traveling wave pulse signal.
由于本发明主要针对的电缆故障类型是电缆开路及断路故障，因此在行波法中采用了比较简单有效的低压脉冲反射法，脉冲电压选取典型值500V，但主要区别是由目前电缆的芯线构成的电路回路改成由铠装层与大地之间构成的回路，因此，本发明发射的行波脉冲电压是施加在电力电缆的测量端的铠装层与大地之间，然后在由电缆的铠装层与大地之间构成的行波传输系统中传播。Since the cable fault type mainly aimed at by the present invention is cable open circuit and open circuit fault, a relatively simple and effective low-voltage pulse reflection method is adopted in the traveling wave method, and the pulse voltage is selected as a typical value of 500V, but the main difference is that the core wire The formed circuit loop is changed into a loop formed between the armored layer and the earth. Therefore, the traveling wave pulse voltage emitted by the present invention is applied between the armored layer and the earth at the measuring end of the power cable, and then is passed between the armored layer of the cable and the earth. It propagates in the traveling wave transmission system formed between the coating layer and the earth.
为了实现电缆故障的在线测距，其前提是要及时发现故障，因此本发明需要连续不断地从测量端发射低压行波脉冲信号，并记录发射的行波信号波形以及发射时间，以便后续步骤能够不断地针对反射行波信号的特征进行故障判断，从而及时地发现电缆故障。In order to realize the on-line distance measurement of cable faults, the premise is to find the faults in time, so the present invention needs to continuously transmit low-voltage traveling wave pulse signals from the measuring end, and record the transmitted traveling wave signal waveform and transmission time, so that the subsequent steps can Continuously carry out fault judgment based on the characteristics of the reflected traveling wave signal, so as to discover cable faults in time.
设计发射脉冲的时间宽度和前后脉冲间的时间间隔需要根据故障点的距离及反射行波信号的检测难度(或故障测距精度)来综合决定。以故障点距离为例，假设脉冲发射宽度是0.5μs，电缆波速度是160m/μs，则其测量盲区为40m，此时就要求其最近故障点距离不能小于40m。具体根据测量距离来选择脉冲宽度，测量距离愈远，脉冲宽度愈宽。The time width of the designed transmitted pulse and the time interval between the preceding and following pulses need to be comprehensively determined according to the distance of the fault point and the detection difficulty of the reflected traveling wave signal (or fault location accuracy). Taking the distance to the fault point as an example, assuming that the pulse emission width is 0.5μs and the cable wave velocity is 160m/μs, the measurement blind zone is 40m. At this time, the distance to the nearest fault point is required to be no less than 40m. Specifically, the pulse width is selected according to the measurement distance. The farther the measurement distance is, the wider the pulse width is.
2)根据电缆测量端收到的反射行波信号，判断有无电缆故障。2) According to the reflected traveling wave signal received by the cable measuring end, judge whether there is a cable fault.
首先根据电缆测量端收到的反射行波信号，判断有无电缆故障。如果电缆没有发生故障，则由于被测电缆的另一端处于阻抗匹配状态，在测量端不会收到反射行波信号；但如果电缆发生故障，则在电缆中的故障点由于阻抗不匹配会产生反射，在测量端就会收到反射行波信号，因此可以据此判断是否发生电缆故障。First, judge whether there is a cable fault according to the reflected traveling wave signal received by the cable measuring end. If there is no fault in the cable, the reflected traveling wave signal will not be received at the measurement end because the other end of the cable under test is in a state of impedance matching; but if the cable is faulty, the fault point in the cable will produce Reflection, the reflected traveling wave signal will be received at the measurement end, so it can be judged whether a cable fault occurs or not.
3)在判断存在电缆故障的情况下，针对测量端收到的反射行波信号，利用小波分析技术进行信号特征分析，从而获得故障反射行波信号到达测量端的准确时间。本发明选择小波分析技术来检测电缆故障，主要是利用了反射行波信号的起始点存在奇异性(信号的奇异点即对应于故障发生时刻)，以及小波变换模极大值的奇异性检测原理(小波变换的模极大值点即为信号的奇异点)。3) In the case of determining the presence of a cable fault, the wavelet analysis technique is used to analyze the signal characteristics of the reflected traveling wave signal received by the measuring end, so as to obtain the accurate time when the fault reflected traveling wave signal reaches the measuring end. The present invention selects wavelet analysis technology to detect cable fault, mainly is to utilize the starting point of reflected traveling wave signal to have singularity (singularity point of signal corresponds to fault occurrence moment), and the principle of singularity detection of wavelet transform modulus maximum value (The modulus maximum point of the wavelet transform is the singularity point of the signal).
利用小波技术分析反射行波信号的主要过程如下：a)对反射行波信号进行小波变换，求取各尺度下的模极大值。观察模极大值在不同尺度下的变化情况，对于随尺度增大，模极大值增大的则保留；随尺度增大，模极大值减小的予以去除，不再考虑。即滤除所有不能向下一尺度传播、和不是由上一尺度传递来的模极大值。b)在低频高尺度下考察保留下的模极大值，寻找反射行波信号的波头最大值出现的位置T1，该时刻为行波波头到达的大致时刻。在高频低尺度下，T1时刻附近领域内查找行波信号突变点，最靠近T1时刻的突变点是初始行波波头的突变信号。c)在确定初始波头到达时刻的尺度下考察模极大值的分布，在初始波头到达后的
在具体应用小波分析技术时，考虑到噪声影响，因此需要预先设定一个合理的阀值，当反射行波信号的小波变换的模极大值大于阀值时，认为电缆有故障；当反射行波信号的小波变换的模极大值小于阀值时，则认为低于阀值的模极大值是由噪声或随机干扰产生的，不属于电缆故障。In the specific application of wavelet analysis technology, considering the influence of noise, it is necessary to set a reasonable threshold in advance. When the modulus maximum value of the wavelet transform of the reflected traveling wave signal is greater than the threshold, it is considered that the cable is faulty; When the modulus maximum value of the wavelet transform of the wavelet signal is less than the threshold value, it is considered that the modulus maximum value lower than the threshold value is generated by noise or random interference, and does not belong to the cable fault.
4)根据测量端得到的发射行波脉冲信号与反射行波信号间的时间差，将测得的发射行波脉冲信号与反射行波信号间的时间差与行波传播速度相乘，除以二即可获得故障点的准确位置。4) According to the time difference between the transmitted traveling wave pulse signal and the reflected traveling wave signal obtained at the measuring end, multiply the measured time difference between the transmitted traveling wave pulse signal and the reflected traveling wave signal by the traveling wave propagation velocity, divide by two The exact location of the fault point can be obtained.
其中，如何准确获得由铠装层与大地构成的行波传输系统的行波传播速度是本发明的另外一个关键环节，其结果将直接影响最终测距精度。但是，本发明的行波传输系统与目前所普遍采用的有较大不同。由于行波是在由圆柱形空心的铠装层和大地构成的行波传输系统中传输，其传输介质相对比较复杂，既包含有电缆最外层的塑胶材料，还包含由敷设方式决定的各种地下环境，这些都会影响行波传播速度，从而影响到测距的准确性。为此，本发明根据铠装层的构造，外护套的材料，以及地下环境，通过电磁仿真分析手段，如商业电磁仿真工具HFSS、ANSYS等，对行波传输系统进行建模分析，从而获得准确的行波传播速度等特性参数。Among them, how to accurately obtain the traveling wave propagation speed of the traveling wave transmission system composed of the armor layer and the ground is another key link of the present invention, and the result will directly affect the final ranging accuracy. However, the traveling wave transmission system of the present invention is quite different from those commonly used at present. Since the traveling wave is transmitted in the traveling wave transmission system composed of the cylindrical hollow armor layer and the earth, its transmission medium is relatively complicated, including not only the plastic material of the outermost layer of the cable, but also various components determined by the laying method. Various underground environments will affect the propagation speed of traveling waves, thereby affecting the accuracy of ranging. For this reason, according to the structure of the armor layer, the material of the outer sheath, and the underground environment, the present invention uses electromagnetic simulation analysis means, such as commercial electromagnetic simulation tools HFSS, ANSYS, etc., to model and analyze the traveling wave transmission system, thereby obtaining Accurate characteristic parameters such as traveling wave propagation speed.
最后需要注意的是，公布实施例的目的在于帮助进一步理解本发明，但是本领域的技术人员可以理解：在不脱离本发明及所附的权利要求的精神和范围内，各种替换和修改都是可能的。因此，本发明不应局限于实施例所公开的内容，本发明要求保护的范围以权利要求书界定的范围为准。Finally, it should be noted that the purpose of the disclosed embodiments is to help further understand the present invention, but those skilled in the art can understand that various replacements and modifications can be made without departing from the spirit and scope of the present invention and the appended claims. It is possible. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the protection scope of the present invention is subject to the scope defined in the claims.
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Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105319229A (en) * | 2014-06-24 | 2016-02-10 | 国家电网公司 | Defect detecting method and system of high voltage buried cables |
| CN105445624A (en) * | 2015-11-26 | 2016-03-30 | 重庆大学 | Cable fault positioning method according to combination of wavelet transformation and curve fitting |
| CN105469522A (en) * | 2015-11-16 | 2016-04-06 | 国网重庆市电力公司电力科学研究院 | Cable antitheft method and device |
| CN105988066A (en) * | 2015-02-09 | 2016-10-05 | 华北电力大学（保定） | Double-end partial discharging positioning method of long-distance cable based on correction pulses |
| CN106249104A (en) * | 2016-07-29 | 2016-12-21 | 山东康威通信技术股份有限公司 | A kind of detection device and method of communication cable shielding layer status monitoring |
| CN106291241A (en) * | 2016-08-11 | 2017-01-04 | 国网天津市电力公司 | A kind of electric power cable intelligent fault warning system |
| CN109541400A (en) * | 2018-12-14 | 2019-03-29 | 广东电网有限责任公司 | A kind of contactless method for obtaining transient voltage travelling wave signal |
| CN109884462A (en) * | 2018-12-03 | 2019-06-14 | 国家电网有限公司 | A kind of the short trouble localization method and system of high voltage single-core cable |
| CN109905084A (en) * | 2019-03-01 | 2019-06-18 | 华为技术有限公司 | Method, device and photovoltaic system for judging fault point location |
| CN110221184A (en) * | 2019-07-17 | 2019-09-10 | 广东电网有限责任公司 | Middle pressure single-core crosslinked cable metal screen layer fault detection device and detection method |
| CN110346690A (en) * | 2019-08-15 | 2019-10-18 | 广东电网有限责任公司 | Sea cable fault localization system and method based on fiber pulse transmission |
| CN110470945A (en) * | 2019-07-15 | 2019-11-19 | 福建省万维新能源电力有限公司 | A kind of power transmission and transformation line fault detecting and positioning method |
| CN111273129A (en) * | 2020-03-02 | 2020-06-12 | 深圳供电局有限公司 | Cable defect detection method and device based on composite test signal |
| CN111638423A (en) * | 2020-06-19 | 2020-09-08 | 长沙理工大学 | Power cable positioning method for grounding faults of sheath layer and armor layer |
| CN112526485A (en) * | 2019-09-18 | 2021-03-19 | Oppo广东移动通信有限公司 | Fault detection method and device, equipment and storage medium |
| CN113884808A (en) * | 2021-09-28 | 2022-01-04 | 华北电力大学（保定） | A cable fault detection system and its fault location method |
| CN114371367A (en) * | 2022-01-14 | 2022-04-19 | 国网黑龙江省电力有限公司哈尔滨供电公司 | Method, system, device and program for detecting faults of power distribution network cable line |
| CN116125196A (en) * | 2022-12-02 | 2023-05-16 | 南京大贺电力科技有限公司 | High-voltage cable fault traveling wave ranging system and method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4151460A (en) * | 1977-09-30 | 1979-04-24 | Westinghouse Electric Corp. | High resistance ground fault detector and locator for polyphase electrical systems |
| CN1078308A (en) * | 1993-04-02 | 1993-11-10 | 肖战立 | The lookup method of sheathed cable earth fault |
| CN101359022A (en) * | 2008-08-20 | 2009-02-04 | 东南大学 | Solar power generation's superhigh pressure circuit monitoring system |
-
2013
- 2013-03-22 CN CN2013100934149A patent/CN103217612A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4151460A (en) * | 1977-09-30 | 1979-04-24 | Westinghouse Electric Corp. | High resistance ground fault detector and locator for polyphase electrical systems |
| CN1078308A (en) * | 1993-04-02 | 1993-11-10 | 肖战立 | The lookup method of sheathed cable earth fault |
| CN101359022A (en) * | 2008-08-20 | 2009-02-04 | 东南大学 | Solar power generation's superhigh pressure circuit monitoring system |
Non-Patent Citations (2)
| Title |
|---|
| 杨艳伟: "基于低压脉冲法的电缆故障测距的研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
| 白春涛: "电力电缆故障低压脉冲自动测距方法研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
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