DL/T 2008-2019 in English

Technical background and evolution of standards

DL/T 2008-2019 is my country's first special test standard for composite connections of power transformers, enclosed combination appliances and power cables, filling the technical gap in on-site detection of new connection methods such as oil and gas casings and plug-in terminals. Based on the GB 50150 acceptance test specification, this standard focuses on solving the problem of coordinated detection of the interface parts of the three types of equipment.

Comparison of core test items

Detailed explanation of key test methods

1. Composite connection sealing test

Use local bandaging method and leak detector for double detection:

• The sensitivity of the leak detector must reach 1×10^-6 (volume ratio)
• Measurement is carried out after inflation for 24 hours
• Typical leakage rate ≤0.5%/year (GB 8905)

2. AC withstand voltage test

Adopt the minimum withstand voltage of the equipment principle:

Implementation recommendations

1. Standardization of test positions: It is recommended to fix the test point at the grounding switch ES1 (Appendix A.1)
2. Data comparability: The winding deformation test needs to maintain the same wiring method
3. Safety protection: DS1 must be disconnected and ES2 must be closed during the withstand voltage test

Technology development prospects

This standard provides a basic framework for the integrated detection of future smart substation equipment. The following needs to be supplemented in the future:

• Partial discharge online monitoring interface specification
• SF6/oil interface status assessment method
• High-frequency impedance detection technology