Location Method of High Resistance Damage in Power Cable Line

In order to preliminarily determine the high resistance damage in power cable lines, the combination method of high voltage reflection method is usually used: pulse arc method and vibration discharge method. In this paper, we will consider the main ideas embedded in these methods and how they work. In addition, we will discuss the equipment to implement these two methods. 1、 Pulse arc method (ARM) is used to determine high resistance damage. The main idea of pulse arc method is to use a special high-voltage pulse generator. For example, in the arc cable generator of power cable, oil first creates conditions for the generation of high resistance defects and causes short-term arc (breakdown). According to the magnitude of the leakage current and the power of the current source, use one of two ways for the generator to act on the cable line: 1. Smoothly charge KL's own capacity (cable) from the generator current source until breakdown occurs. This method can be used if the leakage is so small that the power supply of the high voltage pulse generator is sufficient to charge before breakdown. For defects with serious leakage, this method is not applicable. 2. Charge the built-in capacitor of the generator to the required voltage (not exceeding the test standard), and then discharge the cable instantaneously. In this case, the high-voltage pulse propagates in the cable, which will lead to failure when it reaches the location of the defect. This method can be used to search for defects on cable lines with serious leakage. In both cases, the use of inductors integrated in the generator will delay the arc combustion time. The current pulse from the breakdown (propagating from the defect to the input of the generator) triggers a synchronous circuit that starts the low-voltage sounding through the cable fault locator (also known as the cable fault tester). The physical characteristics of the arc have low resistance, and the detection pulse of the cable fault locator is also reflected from medium and low impedance defects (short circuit). Advantages of pulsed arc method the pulsed arc method (ARM) for determining high resistance damage has several advantages. This is a non-destructive method, because unlike combustion, the impact of high voltage on the cable is short. Unlike combustion, this method will not reduce the cable parameters as a whole, and will not cause new damage where the insulation resistance is still within the normal range. Arm is actually a high-precision method, because the measurement is actually carried out by pulse method. 2、 The vibration discharge method (ice / attenuation) should deal with high resistance damage. The vibration discharge method is used to find damage on a long cable line, or when the pulse damping of the underground cable fault locator is too large for some reason to apply the pulse arc method. The vibratory discharge method allows you to locate most faults that can be detected using the pulsed arc method, but usually reduces accuracy. It should be noted here that the function of the cable is not displayed when operating by the vibration discharge method. Current oscillation discharge method (current fluctuation method, ice) when the wave current method is used, the oscillation circuit is formed by the system: capacitor on the source side - Cable - low transition resistance (or arc) at the defective part. When the method of vibration discharge through current is used, according to the leakage current value and the power of the current source, here, as with the pulse arc method, one of the two methods of exposing the cable to the generator is used: 1. Smoothly charge the CL capacitor from the generator current source until breakdown occurs. This method can be used if the leakage is so small that the power of the current source is sufficient to charge before breakdown. For defects with serious leakage, this method is not applicable. 2. Charge the built-in capacitor of the generator to the required voltage (not exceeding the test standard), and then discharge the cable instantaneously. In this case, the high-voltage pulse propagates in the and reaches the defective part, resulting in breakdown or large discharge current. This method can be used to search for serious defects. The discharge current pulse returned to the source will charge its capacitor, which in turn. The wave reaching the defect may cause a discharge in it again (in this case, its polarity will change), or if a second discharge does not occur, it will reflect with the same polarity and repeat the process again until all the energy of the initial pulse disappears. These vibrations are displayed on the screen of the cable fault locator connected to the cable through the inductive sensor.

Location Method of High Resistance Damage in Power Cable Line 1

recommended articles
Info Center News
Theory of Cable Fault Locator
The basic function of cable fault locator is in the power industry and some industries using cables, especially in some complex power systems. It is very difficult to find the fault of underground cable lines. However, in this regard, the continuous emergence of equipment with various functions and simple operation can not only reduce the high cost of fault detection, but also reduce the inevitable long-time power failure when difficult to find (cable fault locator) cable fault, which brings a lot of convenience to troubleshooting. Direct buried cable fault detection in underground direct buried cable and underground residential power distribution (URD) system is a very time-consuming thing, and will cause very inconvenient power failure to users. Some technologies may also damage the cable. For some equipment with high technical requirements, its operation is more complex, and only operators with strict training can use it, which brings a lot of inconvenience to the popularization and application of this kind of technical equipment. Therefore, the selection of appropriate technology depends partly on the knowledge of cable system design understood by the designer of fault detector, and also partly on the professional and technical knowledge of equipment and operators in this regard. With appropriate equipment and professional technology working on site, it is the first step to detect faults quickly and effectively. Hammering (pulse) method many power companies use hammering (pulse) method. This technique is effective in detecting high resistance faults in a simple (cable fault locator) cable system. The hammering method includes using a pulse or impulse voltage to impact the power cut cable. When an effective high voltage pulse strikes the fault area, the fault point flashover and produces a hammering sound that can be heard by the operator along the cable surface. However, detecting cable faults often requires several hammers, and repeated shocks may damage the cable. Dear customers: Hello, our company is a high-quality development group with strong technical force, providing users with high-quality products, complete solutions and superior technical services. The enterprise adheres to the tenet of building a business in good faith, keeping the business with quality and developing the business with enterprising. It continues to climb new peaks with a firmer pace and make contributions to the national automation industry. New and old customers are welcome to buy their favorite products at ease. We will serve you wholeheartedly!
Function of Cable Fault Locator
Introduction of Underground Pipeline Detector
Brief Introduction of Cable Fault Locator
Working Principle of High Voltage Cable Fault Tester
Working Principle of Cable Fault Locator
Functional Characteristics of Live Cable Identification Instrument
Basic Principle of Live Cable Identification Instrument
Introduction to Underground Pipeline Detector
Basic Introduction of Power Cable Fault Tester
related searches
Theory of Cable Fault Locator
Function of Cable Fault Locator
Introduction of Underground Pipeline Detector
Brief Introduction of Cable Fault Locator
Working Principle of High Voltage Cable Fault Tester
Working Principle of Cable Fault Locator
Functional Characteristics of Live Cable Identification Instrument
Basic Principle of Live Cable Identification Instrument
Introduction to Underground Pipeline Detector
During 15 years development, Noyafa has become the most famous brand in cable testing industry in China. With excellent production capability, reliable quality, good after-sales service, we get good reputation from customers all over the world.
no data
Contact Person:Lory Liu
Contact Us

+86-0755-27530990

If you have any question, please contact Lorry via

wire@noyafa.com

Add:Wanjing Business Center, #2506 Xinyu Road, Xinqiao, Baoan District, Shenzhen, China

Copyright © 2021 NOYAFA | Sitemap 

chat online
Please message us and we ensure to respond ASAP, what product you intrested in?