Cable Fault Pre-locator | 400MHz Multiple Pulse Power Cable Fault Locator for

产品概述

XHGG502A电缆故障预定位仪是一款用于测量和分析电力电缆状况及故障距离的专用仪器.它采用工业级10.1英寸触摸屏一体机,配备简易的操作软件界面,方便人机交互测试；并采用工业级集成电路和元器件,内置高容量锂离子电池,确保了仪器的稳定性,可靠性和易用性.

它结合了现代电子和计算机技术,实现了信号滤波,采集,数据处理,图形显示和图形分析,从而完成了电缆速度测量,电缆长度测试和电缆故障距离测试.它适用于各种截面和介质的电力电缆,高频同轴电缆,路灯电缆和埋地电缆的低阻,短路,开路和断路故障,以及高阻泄漏和高阻闪络故障. 

主要特点

• 10.1英寸全彩TFT触摸屏显示器
• 嵌入式系统提供安全,稳定,简便的显示和操作.
• 测试电缆波速,电缆长度和故障距离
• 全自动连续采样和实时波形捕获,及时准确
• 自动测试范围设置和自动波形分析,并显示测试距离
• 全中文菜单,两种操作模式——触摸和按键编码——简单,快捷,可靠
• 低压脉冲法,高压闪络法和多脉冲法(8个脉冲)；波形平滑,非常容易解读
• 在多脉冲法中,使用脉冲耦合器显示8组高/低电压波形,以便于进行自动距离测试,手动分析和距离测量.
• 强大的数据处理能力,方便波形文件管理和归档
• 海量波形存储:以中文命名存储现场波形,方便随时检索；可存储超过8000条低压脉冲和高压闪络波形记录以及超过250条多脉冲波形记录；波形文件可通过USB导入PC软件.
• 超高亮度LED背光,亮度高达280尼特,分辨率为1024×600,适用于阳光直射环境.
• 内置高容量锂电池组,支持快速充电,可在无电源环境下进行测试.
• 防护等级至少为 IP54 的防护底盘

电缆分类及故障类型 电缆故障类型

• 开路故障:电缆绝缘层正常,但由于导体缺陷,电压无法正常传输——例如,芯线或地线部分断裂,芯线某一点的线路电阻过大,或者芯线断裂.单纯的开路故障很少见；它们通常与低阻或高阻故障同时存在.
• 低阻故障:相间或相地故障,由于绝缘层受损,可以直接用低压脉冲法进行测试；电阻通常低于几百欧姆.如果电阻为零,则称为短路故障,它是低阻故障的一种特殊情况.
• 漏电高阻故障:绝缘层损坏,形成固定电阻通路,无法用低压脉冲法直接测量；电阻通常为几百欧姆或更高.
• 闪络高阻故障:在预测试电压范围内,当预测试电压达到一定值时,漏电流突然增大,远远超过规定值；绝缘损坏,但没有形成固定电阻通路.

测试程序

1. 分析电缆故障的性质,了解故障电缆的耐压等级和绝缘介质.
2. 使用低压脉冲功能测试故障电缆所有相线的长度,并校准电缆的波传输速度.
3. 选择合适的测试方法,对电缆故障进行初步测试.
4. 对故障点进行精确测量,包括确定埋地电缆的走向和深度,并精确定位故障点.
5. 对结果进行误差分析(测量误差,传输速度误差,解释误差和仪器误差).

工作原理 行波法

当电磁波在不均匀的传输线中传播时——即某点的特性阻抗发生变化时——波不仅会继续向前传播,还会产生反向传播回到测试端.这种反向传播的波称为反射波,这种现象称为反射；入射波和反射波合起来称为行波.在短路点,回波的极性与发射脉冲的极性相反；而在开路点(包括电缆端子),回波的极性与发射脉冲的极性相同.因此,低阻故障和开路故障可以根据回波极性,通过低压脉冲法轻松定位.对于高阻故障,则采用高压闪络法:高压脉冲信号源(漏电高阻故障)或直流高压电源(闪络高阻故障)在故障点产生闪络放电,产生反射信号,该信号在测试端被检测到.反射信号随后通过高速 A/D 转换器和计算机控制系统,从模拟信号转换为数字信号,存储并进行数字处理,然后发送到显示器进行波形分析——完成故障距离的粗略测量.

低压脉冲法

对被测电缆施加低压脉冲信号；脉冲在故障点反射,测试仪处理反射信号并显示波形,通过分析反射波形确定粗略故障距离.

高压闪络法

• 直接闪络法:主要用于检测高阻闪络故障.直流高压电源向故障电缆施加直流电压；当电压达到一定值时,故障点会发生突发闪络放电,产生反射信号,该信号由专用采样器接收并传输至测试仪进行处理和分析.
• Impulse flashover method (universal method): primarily used to test high-resistance leakage faults. A high-voltage pulse signal source applies a high-voltage pulse signal to the faulty cable; the pulse passes through the fault point, causing flashover discharge and a reflected signal, which is received by the dedicated sampler and transmitted to the tester for processing and analysis.

Multiple-pulse method

The system includes an integrated high-voltage generator capable of generating a single-impact high voltage, a multiple-pulse generator, a multiple-pulse automatic triggering device and test waveform analysis software. The multiple-pulse generator guides the instantaneous high-voltage pulse onto the faulty phase, ensuring sufficient breakdown at the fault point and extending the arc duration after breakdown. The automatic triggering device then immediately sends out multiple low-voltage test pulses. The first eight test pulses use the short-circuit characteristics at the moment of cable arc breakdown to form eight fault reflection pulses; after the arc extinguishes, eight more test pulses measure the cable's open-circuit reflection waveform, forming eight sets of secondary pulse waveforms. The multiple-pulse method effectively avoids the interference of the large cosine oscillations that occur under high-voltage impact, allowing clear standard echoes resembling a short-circuit fault to be obtained during the relatively stable arc — greatly simplifying the testing procedure.

Technical Specifications Instrument Layout & ComponentsThe instrument set consists of the cable fault tester (which uses the low-voltage pulse method, high-voltage flashover method and multiple-pulse method to test and analyse cables), a coupler (used for the multiple-pulse method), a single-Q output line (connects the tester to the cable under test during the low-voltage pulse method), a dual-Q input line (connects the tester and sampler during high-voltage flashover testing), a sampler (receives the high-voltage signal reflected onto the sampling ground), a power cord (charging cable), coupler high-voltage line A (connects the coupler to the cable under test in the multiple-pulse method; plug / unplug only, do not rotate or screw), coupler high-voltage line B (connects the coupler to the high-voltage pulse signal source in the multiple-pulse method; plug / unplug only, do not rotate or screw), a ground wire (coupler ground wire) and a USB cable (for importing waveform files to a computer).Front panel items adjust the amplitude knob during waveform acquisition to change the amplitude of the acquired waveformOperation Guide Software main interface

After the boot screen the system operation interface is shown. The main interface is divided into a working-status indicator area, a waveform display area, an instrument parameter display area, a function setting area and an instrument operation area. The working-status area displays "Standby Status" when the instrument is ready and switches to "Sampling Status" when the sampling button is pressed.

The function setting area includes: medium speed (cross-linked, oil-immersed and rubber cable types; cable propagation speed can be customised); operating modes (five methods: pulse, flashover, velocimetry, multiple measurements and megohmmeter); test range (100 m / 300 m / 500 m / 1 km / 3 km / 5 km / 10 km / 25 km / 50 km / 100 km); file processing (save the current waveform, open previously saved waveforms for comparison, and export waveform files to PC software); sample / hold (start and stop sampling; the waveform display area then refreshes in real time); and system settings (set the system time, turn the auto-range function on / off, adjust brightness and turn the operation feedback buzzer on / off).

The waveform display area shows the real-time sampled waveform in the middle, the test results and distance / wave velocity on the right, and the current instrument parameters at the bottom. The instrument operation area provides amplitude adjustment (three levels X1, X2 and X3; can also be adjusted with the panel amplitude knob during sampling), baseline adjustment (in sampling mode, adjust the upper and lower baseline positions with the "baseline up" and "baseline down" buttons), waveform compression (in hold, use the "Waveform Compression" button to compress or expand the waveform), cursor (while holding the distance, press the "Cursor" button and select cursor 1 or cursor 2, then use the left / right keys to adjust the cursor positions, or press and drag the bottom of the cursor; there are 6 levels X1–X6, where a larger number means a greater distance per step) and automatic measurement (in hold or sampling mode, pressing "Automatic Measurement" automatically calculates the distance result).

Low-voltage pulse method

1. In the function settings area, select the medium speed, choose low-voltage pulse mode and select an appropriate test range; if automatic range determination is required, check "Auto-range" in the system settings.
2. After completing the parameter settings, click "Sampling"; the instrument automatically performs low-voltage pulse sampling. Adjust the "baseline" and "amplitude" as needed and observe the sampled echo so that the waveform has no upper or lower amplitude limits, until the echo amplitude is suitable for analysis.
3. Press "Hold" to stop sampling. Use the overall waveform control area to move and compress the waveform until it is in the best state for analysis, then use the cursor to set the distance and interpret the waveform.
4. Click "File Processing" to save the current waveform for later viewing and comparison.

High-voltage flashover method

1. Select the medium speed, choose high-voltage flashover mode and select an appropriate test range; check "Auto-range" in the system settings if automatic range determination is required.
2. After completing the parameter settings, click "Sampling". After the reflected signal is received via the dedicated sampler, adjust the "baseline" and "amplitude" as needed and observe the sampled echo, until the echo amplitude is suitable for analysis.
3. Press "Hold" to stop sampling; move and compress the waveform until it is in the best state for analysis, then use the cursor to set the distance and interpret the waveform.
4. Click "File Processing" to save the current waveform.

Multi-pulse method

1. Select the medium speed, choose multi-pulse mode and select an appropriate test range; check "Auto-range" in the system settings if automatic range determination is required.
2. After completing the parameter settings, click "Sampling". After the reflected signal is received via the dedicated coupler, adjust the "baseline" and "amplitude" as needed until the echo amplitude is suitable for analysis.
3. The waveform display area shows waveform number 4 by default; if that group is not satisfactory or cannot be analysed, click the "1–8" analog keys on the left of the screen to display the corresponding multiple-pulse group.
4. During analysis, the automatic measurement key can be pressed in sampling / hold mode to measure the distance, or the cursor key can be pressed in hold mode for manual analysis and waveform compression.
5. Move the cursor to determine the fault distance, keeping it accurately aligned with the leading inflection point of the transmitted pulse and of the fault echo pulse for precise readings.
6. Click "File Processing" to save the current waveform.

Precautions

• Read this manual carefully and follow the relevant precautions. Violent impacts to the instrument and unauthorised shutdown are strictly prohibited.
• Connect the test leads correctly, especially the grounding wire and the high-voltage wire.
• When connecting for the high-voltage flashover or multiple-pulse method, the instrument software must not be set to the low-voltage pulse method.
• High-voltage flashover method and multiple-pulse method sampling are strictly prohibited while the instrument is charging.
• When the battery is low, charge it before use. The instrument is AC / DC dual-use with a built-in high-capacity lithium battery; if it is not used for a long time, charge and maintain it about every 2 months to prevent the battery from being depleted and damaged by self-discharge.
• Before use, check that the power supply is sufficient to prevent the industrial control computer from malfunctioning due to insufficient power — repeated shutdowns / restarts may lead to system file corruption (1 hour of charging provides 2.5 hours of standby; 2 hours of charging fully charges the battery from zero).
• When the instrument is used only for low-voltage pulse method testing, it can be powered by AC 220 V; it is strictly forbidden to connect AC 220 V for high-voltage flashover method or multiple-pulse method sampling tests.
• The instrument is a highly precise electronic device and must not be disassembled by non-professionals; handle it with care during transport, and rough handling or impact is strictly prohibited.
• If the instrument malfunctions, contact the dealer or the company immediately. Damage caused by human error will void the instrument warranty.
• During low-voltage pulse testing, confirm that there is no residual electricity in the cable itself.

After-Sales Service

The instrument is covered by a one-year warranty from the date of purchase for product quality issues, and lifetime maintenance and technical services are provided. If you find any abnormality or malfunction in the instrument, please contact us so that we can arrange the most convenient and effective solution for you.

FAQ