15
operation functions of the controller can be operated on the software, such as setting parameters,
starting the boosting test, saving historical data, etc.
VI. Power cable withstand voltage test method
1.
Disconnect all electrical equipment connected to the tested cable.
2.
Use a megger to test the insulation parameters of each phase of the cable, and carry out the
ultra-low frequency withstand voltage test only after the test isqualified.
3.
Set the test voltage value: Umax = 3uo, where uo is the rated phase voltage ofthe cable.
Example 1: cable parameter: the rated line voltage is 10kV, and the rated phase voltage uo =
6kV, so the test voltage setting value is:
Umax = 3uo = 18kV
See Table 4 for the setting value of 0.1Hz ultra-low frequency test voltage of various rubber and
plastic insulated power cables.
Table 4 0.1Hz ultra-low frequency test voltage and time of various rubber plastic insulated
power cables.
Rated
voltage
U
0
/U
S
(kV)
Handover test
Preventive experiment
multi
ple
Test
voltage
（
kV
）
Test time
（
mins
）
multip
le
Test
voltage
（
kV
）
Test time
（
mins
）
1.8/3
3U
0
5
60
3U
0
5
15
3.6/6
3U
0
11
60
3U
0
11
15
6/6
3U
0
18
60
3U
0
18
15
6/10
3U
0
18
60
3U
0
18
15
8.7/10
3U
0
26
60
3U
0
26
15
12/20
3U
0
36
60
3U
0
36
15
21/35
3U
0
63
60
3U
0
63
15
26/35
3U
0
78
60
3U
0
78
15
Note: UN is the rated voltage of the cable, and uo is the phase voltage of the cable.
4.
Test time: 60 minutes for handover test and 15 minutes for preventive test.
5.
Setting current value of overcurrent protection:
Estimation method of capacitive current (or leakage current) of ultra-low frequency withstand
voltage test article:
