The cable fault testerunder Wuhan UHV can help many power workers conduct various power tests more conveniently.
The cable fault detection methods mainly include the following, which can be flexibly selected and used according to the type of fault and actual situation:
1. Non destructive testing method
Non destructive testing method uses physical means to detect cables without damaging the cables themselves. Common non-destructive testing methods include:
Infrared thermography: Determine the presence of a fault by detecting changes in heat on the surface of the faulty cable. Infrared thermal imaging cameras can quickly and accurately locate potential hotspots in cables.
Ultrasonic testing: By sending ultrasonic signals and receiving reflected signals, the fault points inside the cable are detected. The ultrasonic detector can monitor the sound wave reflection signal of the cable in real time and determine the location and type of the fault through analysis.
Electromagnetic wave detection: using the propagation characteristics of electromagnetic waves to detect cable faults. This method can quickly locate the location and type of cable faults.
2. Electrical testing method
The electrical testing method determines whether a cable has a fault by detecting changes in parameters such as voltage, current, and resistance of the cable. Common electrical testing methods include:
Partial discharge detection of cables: Real time monitoring of discharge conditions in cables, identifying the location of faults and carrying out repairs. The partial discharge detector can accurately detect the discharge signal and determine whether there is a fault in the cable.
Cable harmonic analysis: By analyzing the current harmonic components of the cable, the type and location of the fault can be determined. Harmonic analyzer can accurately identify fault points in cables and carry out corresponding repairs.
3. Intelligent detection method
The intelligent detection method combines technologies such as the Internet of Things, big data analysis, and artificial intelligence to use sensors and cloud platforms for real-time monitoring and data analysis of cables, achieving early warning and remote monitoring of faults. Intelligent detection methods can improve the accuracy and efficiency of fault detection.
4. Other specific testing methods
Bridge method: Use a double arm bridge to measure the DC resistance value of the cable core wire, then measure the actual length of the cable, and calculate the cable fault point through the proportional relationship between resistance and length.
Zero potential method: suitable for measuring ground faults in long wire cable cores through potential comparison method.
Acoustic method: Relying on the sound of cable discharge faults, especially for the flashover discharge of high-voltage cable cores to insulation layers, is more effective.
Capacitive current measurement method: Using the proportional relationship between the capacitance between cable core wires and the capacitance between the core wires and the ground, and the length of the cable, the disconnection point is detected by measuring the capacitive current.
induce
There are various methods for cable fault detection, ranging from traditional non-destructive testing methods, electrical testing methods to modern intelligent testing methods, each with its unique advantages and applicable scope. In practical applications, it is necessary to select appropriate detection methods based on the type of cable fault, the burial environment of the cable, and the experience and technical level of the testing personnel. Meanwhile, with the continuous development of technology, cable fault detection methods and tools are constantly improving and updating, providing strong support for the stable operation of the power system.
