The DC high-voltage generator under the UHV power company can help many power workers conduct various power tests more conveniently.

1. Before testing, conduct a test on the cable and fully discharge it to the ground; Disconnect the devices connected at both ends of the cable and do not connect any other devices during the testing process; Clean the insulation surfaces at both ends of the cable head to reduce leakage current caused by the surface. If necessary, insulation barriers should be installed between the phases of the cable head.

2. Safety measures such as fences should be taken at the testing site. Especially at the other end of the cable, a warning sign should be hung and a dedicated person should be assigned to guard to prevent outsiders from approaching, and to check whether the grounding wire and discharge rod are well connected.

3. When applying pressure, the voltage should be gradually increased to prevent excessive charging current. After staying at 0.25, 0.5, 0.75, and 1.0 times the test voltage for 1 minute, the leakage current value should be read; Conduct a voltage withstand test at the designated time and read the leakage current value after the voltage withstand test before the end of the test.

4. According to the type of cable, microampere meters have different wiring methods. Generally, the microampere meter is connected to the high voltage side, and the high voltage lead and microampere meter are shielded. For power cables with copper wire mesh shielding layer and grounding insulation, a microampere meter can also be connected in series with the grounding circuit of the tested cable, and a discharge switch can be connected in parallel at both ends of the microampere meter, which is turned on during measurement., Close the switch before discharging after measurement to avoid damaging the microampere meter due to the influence of discharge current.

5. The test voltage should be measured directly on the high voltage side. Because when using half wave rectification or double voltage rectification, if the method of converting the measured voltage on the low voltage side to the voltage on the high voltage side is adopted, the amplitude of the high voltage test voltage may be relatively high due to the influence of voltage waveform and transformation ratio errors and stray currents. The error is large, and the test voltage should be directly measured on the high voltage side.

6. After each voltage withstand test, the voltage should be reduced and the power should be cut off first. Then, discharge the cable to ground several times with a current limiting resistor of about 80k Ω per kV, and then discharge it directly to ground. The discharge time should not be less than 5 minutes to ensure complete discharge.