What are the Inspection Items for 10kV Power Transformers (2024)

In electrical systems, transformers are critical components, and their performance and reliability directly affect the safety and stability of power supply. Therefore, conducting a series of tests on 10kV power transformers in accordance with relevant industry standards and technical specifications is essential. These tests aim to verify the insulation properties, electrical characteristics, and mechanical stability of transformers to ensure their normal operation under various conditions. This article systematically introduces the main testing items for 10kV transformers, based on national standards and recommendations from authoritative organizations such as the International Electrotechnical Commission (IEC).

The testing items for power transformers should include the following:

Insulating Oil Test or SF6 Gas Test: Used to assess the performance of insulating media.
Measurement of Direct Current Resistance of Windings and Bushings: To check the resistance values and determine conductivity.
Check of the Voltage Ratio of All Tap Changers: To ensure compliance with design specifications.
Verification of the Three-Phase Connection Group and Polarity of Single-Phase Transformer Leads: To confirm correct wiring.
Measurement of Insulation Resistance between Fasteners and Core: Ensuring insulation safety.
Testing of Non-Pure Porcelain Bushings: To evaluate the insulation performance of bushing materials.
Inspection and Testing of On-Load Tap-Changing Device: To ensure the functionality of the voltage regulation device.
Measurement of Insulation Resistance, Absorption Ratio, or Polarization Index of Windings and Bushings: To evaluate insulation performance.
Measurement of the Dielectric Loss Tangent (tanδ) of Windings and Bushings: To determine the loss characteristics of the insulating medium.
Measurement of Direct Current Leakage Current of Windings and Bushings: To check if leakage current is within safe limits.
Transformer Winding Deformation Test: To confirm mechanical stability under varying conditions.
AC High-Voltage Test of Windings and Bushings: To verify voltage withstand capability.
Long Duration Induced Voltage Test and Partial Discharge Test of Windings and Bushings: To assess long-term operational safety.
Closing Test Under Rated Voltage: To test the device's response capabilities in emergencies.
Phase Verification: To ensure phase consistency and accuracy.
Noise Measurement: To assess the noise level during operation.

Through a comprehensive understanding of the various testing items for 10kV power transformers, it is evident that a rigorous testing process is fundamental to ensuring the reliable operation of transformers. These tests not only detect insulation status and mechanical strength but also evaluate performance under different load conditions. As discussed in this article, from testing insulating oil and gases to measuring resistance, dielectric loss, and performing high-voltage tests, numerous critical parameters of transformers are covered. Only through scientific testing and rigorous evaluation can we effectively reduce risks in electrical systems, enhance operational efficiency, and prolong equipment lifespan. Therefore, testing should be regarded as an indispensable aspect in the design, manufacture, and installation of transformers to ensure the safety, stability, and efficiency of power systems.