By sion932 
Intelligent warning, safeguarding the lifeline of urban power supply
Do you know that a malfunction of a high-voltage cable could plunge an entire city into darkness? In modern power systems with large construction sites and dense cable channels, high-voltage power cables serve as the “main artery” of power transmission, and their safety directly affects the stable operation of the entire power grid.
However, in reality, the three major challenges of fire hazards, external damage, and uncontrolled equipment status are like the Damocles sword hanging over the power system, and traditional manual detection methods are no longer able to cope with these challenges.
1、 The ‘invisible killer’ of high-voltage cables: deadly hazards you don’t know about
Walking underground in the city, high-voltage cables crisscross like the blood vessel network of the human body. But this’ lifeline ‘is facing multiple threats:
Fire hazards are prominent: High voltage and low voltage cables are often laid in the same channel and multiple circuits densely. With the passage of time, the problem of cable insulation aging has become increasingly serious. Due to long-term lack of inspection, the insulation layer of a tunnel cable in a coastal city eventually lost its insulation properties, causing a short circuit and fire, resulting in a large-scale power outage.
High incidence of external damage: Temporary construction is rampant in urban construction, and construction personnel have weak safety awareness. What is even more headache inducing is that excavation operations near cable trenches, and even theft of cable terminal towers, are frequent, making it extremely difficult to control such external damage.
Equipment status out of control: Many units still rely on manual inspections and use online monitoring devices with poor stability and high failure rates, which cannot accurately grasp the insulation status of cables. The power supply bureau of a certain provincial capital city once experienced an 8-hour delay in locating the fault point due to false alarms from monitoring equipment.
2、 Why is traditional testing inadequate? Three major pain points reveal the necessity of upgrading
Why are traditional detection methods inadequate in the face of these hidden dangers? The core pain points are:
Data collection bottleneck: Traditional systems are unable to collect dynamic data in real-time, let alone aggregate multi-source information, resulting in a ‘data island’
Insufficient operation and maintenance capabilities: With the explosive growth of cable channel length, there is a severe shortage of operation and maintenance personnel, and “maintenance beyond the cycle” has become the norm
Limited detection accuracy: Manual detection is susceptible to environmental interference, and the recognition rate of early partial discharge and other hidden dangers is less than 30%
When a power plant uses traditional methods for testing, a set of 12 kilometer high-voltage cables requires three technicians to work continuously for two days to complete basic testing – which is inefficient and has a high rate of missed detections.
3、 The Revolution of Intelligent Detection: How to Achieve “Prevention before Disease”?
Intelligent detectors are reshaping the security line. But facing the dazzling array of products in the market, detection accuracy is the core selection criterion. A true intelligent detection system should possess three major capabilities:
1. Multi dimensional perception ability
The advanced partial discharge testing system can capture nanoscale insulation defects. For example, the variable frequency series resonance test device can accurately identify early insulation degradation by performing cable “physical examination” without power outage through precise voltage and frequency adjustment.
2. Full link data analysis
The modern cable fault tester integrates multiple parameters such as grounding resistance testing and dielectric loss analysis, and is implemented through AI algorithms to:
Prediction of insulation aging trend
Accurate positioning of fault points (error<0.5 meters)
Construction of Remaining Life Assessment Model
3. Adaptive diagnostic capability
Taking the intelligent diagnostic platform developed by our as an example, its equipment ensures signal transmission stability through dual band automatic switching technology (2.4GHz/5GHz), and can transmit data in real-time even in cable trenches 20 meters deep underground.
4、 Practical case: How can intelligent detection turn danger into safety?
In 2024, the warning system of a certain ultra-high voltage substation in the south issued a partial discharge alarm. The operation and maintenance personnel used the our variable frequency series resonance test device for retesting and located a hidden terminal joint defect in just 2 hours. Through experience verification, it was found that there are three millimeter level air gap discharges inside – if not dealt with in a timely manner, it will inevitably cause tripping accidents within three months.
This system integrates the functions of cable fault locator and insulation resistance tester, and improves the detection efficiency by 400% through multi band scanning technology, reducing the annual failure rate by 76%.
5、 The key choice for building a secure defense line: professional equipment+intelligent operation and maintenance
To truly strengthen the security line, we need to take a dual approach:
Equipment Selection Guide:
DC high voltage generator: used to evaluate the withstand voltage strength of cables
Transformer volt ampere characteristic tester: detects the performance of current transformers
Ultra low frequency high voltage generator: non-destructive testing of old cables
Cable Fault Intelligent Tester: The Preferred Integrated Solution
Upgrade of operation and maintenance mode:
Establish a dual track system of “online monitoring+mobile detection”
Deploy 3-5 partial discharge monitoring nodes per kilometer of cable
Conduct quarterly preventive tests using a frequency conversion series resonance test device
As a cutting-edge enterprise in the field of high-voltage detection, our has developed an intelligent diagnostic platform that has been applied in more than 30 key projects in China. The series resonant withstand voltage device developed by the company has been recommended by the State Grid due to its excellent stability and detection accuracy.
5 Common Issues in High Voltage Cable Safety Testing
Q1: How to determine if a cable needs to be replaced?
A: Measure the insulation loss angle using a dielectric loss tester, and issue a warning when the value exceeds 0.02; Based on the partial discharge test data, if the discharge capacity is greater than 100pC, it needs to be replaced immediately.
Q2: What are the advantages of intelligent detectors over manual detection?
A: Taking the detection system of HVHIPOT as an example: the detection accuracy has been improved by 10 times (able to identify 0.1mm ³ bubbles), the detection speed has been increased by 5 times (10 kilometers of cable detection only takes 4 hours), and 90% of early hidden dangers can be detected.
Q3: How to detect water accumulation in cable trenches during the rainy season?
A: The cable fault detector with IP68 protection level is selected, and the insulation resistance tester is used to evaluate the insulation under water immersion. The waterproof equipment of HVHIPOT can work continuously for 8 hours at a depth of 1 meter.
Q4: Under what circumstances must a series resonance test be conducted?
A: Newly put into operation cables, cables that have been repaired, and cables that have been in operation for 5 years should undergo frequency conversion series resonance withstand voltage testing, which is the most effective means of discovering potential insulation defects.
Q5: How to balance detection costs and safety?
A: Establish a three-level detection system: daily use of online monitoring instruments (low-cost), monthly rapid screening with insulation resistance testers, and annual comprehensive preventive testing. This mode can reduce operational costs by 40% while improving security.
When the city in the morning glow is revitalized by stable power supply, those buried underground cables are silently guarded by a new generation of intelligent testing equipment. Choosing precise detection technology is like adding an intelligent lock to the safety of the power grid – after all, preventing fires before they occur is always more valuable than repairing them afterwards.