Power Engineering
Electrical preventive testing is an essential measure for determining whether power equipment can continue to be put into service, preventing losses to electrical equipment, and ensuring the safe operation of the power system. It also constitutes an effective method and the optimal approach for obtaining critical information about the condition of electrical equipment. Accordingly, China mandates that all equipment in the power system undergo preventive testing in accordance with the requirements set forth in the Power Industry’s “Regulations on Preventive Testing of Electrical Equipment,” thereby proactively mitigating potential risks.
These primarily include: transformers, switches, surge arresters, power cables, insulated conductors, relay protection equipment, grounding systems, instrument transformers, capacitors, reactors and arc-suppression coils, as well as high-voltage disconnect switches and fuses.
1. For user‑side electrical equipment and distribution rooms (including box‑type substations) rated at 220 kV and below, perform handover and preventive testing of high‑ and low‑voltage equipment, conduct relay protection tests, and carry out cleaning and maintenance of all types of equipment. Through these tests and cleaning activities, assess the operational status of the equipment, promptly identify operational defects, and propose appropriate recommendations for defect elimination.
2. Emergency repair of distribution equipment and lines: The primary task of the emergency repair team is to promptly address sudden faults in customer power supply—including distribution rooms and overhead lines—efficiently resolving issues in the shortest possible time and restoring power without delay.
3. The primary tasks of the intelligent transformation and upgrade team are to modernize and upgrade distribution rooms (including packaged substations), enabling smart data collection, online digital management, equipment lifecycle tracking, fault prediction, and energy management. Meanwhile, an on-site specialist team provides professional electricity‑use services, delivering customers more reliable, energy‑efficient, and secure power supply.
4. Substation maintenance and operation services primarily involve acting on behalf of users to provide on‑site supervision or conduct regular inspections of their substations.
| Test subject |
Test Items |
| Transformer |
Infrared thermography inspection |
| Dissolved Gas Analysis in Oil |
|
| High-Frequency Partial Discharge Detection |
|
| Core Ground Current Measurement |
|
| Bushings, CT/PT, coupling capacitors |
Infrared thermography inspection |
| High-Frequency Partial Discharge Detection |
|
| Relative dielectric loss factor |
|
| Relative capacitance ratio |
|
| Surge arrester |
Infrared thermography inspection |
| High-Frequency Partial Discharge Detection |
|
| Continuous Current Monitoring During Operation |
|
| GIS ontology |
Infrared thermography inspection |
| Ultra-High Frequency Partial Discharge Detection |
|
| Ultrasonic Partial Discharge Detection |
|
| SF6 gas humidity |
|
| SF6 gas purity |
|
| SF6 gas decomposition products |
|
| SF6 Gas Leak Imaging Detection |
|
| Switchgear cabinet |
Infrared thermography inspection |
| Ultrasonic Partial Discharge |
|
| Transient Voltage Detection |
|
| High-voltage cable |
Infrared thermography inspection |
| Grounding current of the outer sheath |
|
| High-frequency partial discharge, ultra-high-frequency partial discharge, and ultrasonic partial discharge detection for cable terminations and intermediate joints. |
Contact Us
National Service Hotline: 400-027-8938
Mobile (Manager Chen): 133 9714 9829
Address: Building No. 5, Donghu High-tech Industrial Innovation Base, No. 9 Miaoshan Avenue, Miaoshan Development Zone, Jiangxia District, Wuhan City
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