Portable PD Tester with High Frequency Transformer for Power Cables Partial Discharge Test

Portable PD Tester with High Frequency Transformer for Power Cables Partial Discharge Test

How to use GDJF-4 Portable PD Tester with High Frequency Transformer (HFCT)to detect partial discharge in cables?

Due to the special structure of cables, ultrasonic and high-frequency signals cannot be obtained from the outer layer of metal armor, so we can obtain signals from the grounding wire.

When partial discharge occurs inside the cable, high-frequency current will be guided along the grounding wire to the ground,Partial discharge detection achieved by installing high-frequency transformer on the ground wire to detect high-frequency current signals.There is no electrical connection between the measuring

circuit and the tested circuit of the high-frequency transformer, which belongs to non-invasive detection. Therefore, the equipment does not need to be shut down during high-frequency transformer detection.

Firstly, clamp the high-frequency transformer at the cablegrounding wire, and then connect the PD tester for reading and saving.

Horizontal comparison of partial discharge signals of the same type of equipment. The partial discharge signals detected by similar equipment in similar environments should have similar test amplitudes and test spectrum.

Secondly, vertical comparison of historical data of the same equipment. By measuring the partial discharge signal of the same equipment multiple times over a long period of time, the insulation status and degradation trend of the equipment can be tracked.

If there is a significant increase in the measured value or a typical partial discharge pattern appears, it can be determined that there is an abnormality within this test point.If a signal with discharge characteristics is detected, with a small test value and a large number of pulses, it is a typical interference signal.If the test value is large and the number of pulses is small, it is a typical discharge signal.

Main Application Scenarios:

1) On site inspection and status monitoring: Conduct rapid and regular screening of power equipment such as switchgear, transformers, and cable joints in operation (equipped with different sensors).

2) Preliminary fault diagnosis: After discovering abnormal signals, make preliminary judgments and trend analysis.

3) Emergency investigation: After equipment failure, quickly locate suspicious partial discharge sources.

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