With the widespread application of power cables in fields such as power grids, new energy, and rail transit, partial discharge detection has become an important means of evaluating cable insulation status and preventing insulation faults. According to statistics, 82% of insulation faults in cables with voltage levels of 10kV and above can be identified in advance through partial discharge detection. However, facing the wide variety of partial discharge testers in the market, how to scientifically select them has become a practical problem faced by many power operation and maintenance units. Recently, Wuhan UHV Power Technology Co., Ltd. has released a selection guide for partial discharge testers for power cables based on years of industry experience, providing users with reference from multiple dimensions.
Clarifying testing requirements is the first step in selection
Before selecting, the technical department should first clarify the actual usage needs of the unit. Voltage level matching is the primary consideration -10kV distribution networks and 110kV substations have completely different requirements for equipment specifications. According to different detection scenarios, there are significant differences in the selection direction: daily live inspections are the main focus, and handheld combination devices combining high-frequency current method and ultrasonic method should be preferred, which can operate without power outage and have high efficiency; When precise fault location is required, instruments with time-domain reflection or double ended traveling wave positioning functions should be selected; For completion acceptance or quality appraisal, it is recommended to use the oscillation wave method system for comprehensive evaluation.
Core performance parameters determine detection capability
The detection sensitivity and range are the core indicators of partial discharge testers. The minimum detection sensitivity of 10kV distribution network cable detection equipment is not less than 5pC, and the sensitivity of 110kV and above high-voltage cable detection is not less than 2pC, with a range covering the range of 5pC to 10000pC. Taking the Wuhan UHV partial discharge tester as an example, its detection sensitivity can reach<1pC, and the measurement range covers 0.01pC to 10000nC.
The bandwidth range cannot be ignored either. The recommended bandwidth for high-frequency current sensors is between 100kHz and 50MHz, which can effectively capture partial discharge signals while avoiding power frequency and common broadcast interference. The partial discharge tester provides multiple options for lower and upper limit frequencies, meeting the flexible configuration requirements of different testing scenarios.
The anti-interference ability is related to the practicality of the site
The on-site electromagnetic environment is complex, and the anti-interference ability directly determines the reliability of the detection data. The procurement specification for live detection equipment in the power grid in 2026 clearly requires that the partial discharge instrument used on site must have at least 3 interference suppression algorithms. The UHV partial discharge tester is equipped with various anti-interference techniques such as time window method, phase window masking method, and pulse smoothing method to cope with complex on-site environments. In addition, the equipment should have digital signal processing functions such as noise suppression, phase windowing, filter banks, and pulse grouping. Hanging or keeping the sensor away from the tested equipment to record the environmental noise level before testing is also an important step in ensuring the effectiveness of the detection.
The usage scenario and portability need to be considered comprehensively
For outdoor scenarios with high frequency of use, it is recommended to choose models with dust-proof and waterproof casings. Daily inspections should be carried out using handheld integrated design equipment, which is lightweight and easy to operate. The main scenario for distribution network operation and maintenance is daily inspection of 10kV to 35kV cables. It is recommended to choose handheld devices with sensitivity ≥ 5pC, weight ≤ 2kg, and support for multi device detection. The operation and maintenance scenario of high-voltage cables mainly focuses on the detection of 110kV and above main network cables. It is recommended to choose equipment with 4 or more channels for synchronous collection.
Data management and after-sales service cannot be ignored
Modern partial discharge testers should have functions such as data storage, trend analysis, and automatic report generation to facilitate long-term tracking of equipment status. The UHV ішінара разрядты сынаушы adopts an all-in-one design, with software developed based on graphic elements, rich display, analysis, and recording functions, and supports touch operation. The operation interface should have Chinese graphical display and phase map function, which facilitates on-site personnel to intuitively judge the type and severity of discharge.
The procurement cost is only a part of the total cost of ownership, and the expenses for later calibration, maintenance, replacement, and consumables also need to be included in the budget. The annual inspection cost ranges from several hundred to a thousand yuan per unit, and vulnerable parts such as measuring cables and probes need to be replaced on average once every 1 to 2 years.
As a company that has been deeply involved in the field of high-voltage power testing for nearly 22 years, Wuhan UHV Power Technology Co., Ltd. focuses on the research and development and production of series resonance test devices, partial discharge testing systems, high-voltage insulation withstand voltage and other products. The products are widely used for partial discharge detection of power cables, transformers, GIS and other equipment. The relevant person in charge of the company expressed the hope that through this selection guide, more power operation and maintenance units can scientifically configure partial discharge detection equipment, improve the accuracy and efficiency of cable insulation state assessment, and safeguard the safe and stable operation of the power system.
