Test Object and Requirement
The system is specially designed for AC withstand voltage test for below items, with below specifications and requirements.
Test Object | Specifications | Test Frequency | Test Voltage | Test Time |
Power cable | 170kV/2000mm2/10km Capacitance ≤2μF | 30-300Hz | 150kV | 15 mins |
Power cable | 400kV/2000mm2/5km Capacitance ≤0.6μF | 30-300Hz | 220kV | 15 mins |
GIS | 400kV and below Capacitance ≤0.02μF | 30-300Hz | Max. 750kV |
Capacity Determination of the equipment:
4pcs Reactors will be designed, each reactor is 2500 kVA/150kV. Capacity amount is 10000kVA.
Determination:
1) When to do AC withstand voltage testing on 170kV 2000mm2 10kM power cable.
Using 4pcs reactors in paralleled.
Output 150kV/66.6A, testing current is calculated as below:
I=U×103×ω×C×10－6=66A (U:150kV,C:2uF,ω＝2πf (f=35Hz))
2) When to do AC withstand voltage testing on 400kV 2000mm2 5kM power cable,
Using 2pcs reactors in series and then these two groups in paralleled.
Output 300kV/33.3A, testing current is calculated as below:
I=U×103×ω×C×10－6=29A (U:220kV,C:0.6uF,ω＝2πf (f=35Hz))
3) When to do AC withstand voltage testing on 400kV and below voltage degree GIS and etc. equipment, the capacitance is 0.02 uF,
Using 4pcs reactors in series, output 600kVA/16.6A, resonant frequency and testing current is calculated as below:
I=U×103×ω×C×10－6=3.3A (U:512kV,C:0.02uF,ω＝2πf (f=50Hz))
REACTORS TEST OBJECT | Testing Voltage (kV) | REACTOR 2500KVA/150kV | OUTPUT VOLTAGE OF EXCITING TRANSFORMER |
170KV Power Cable | 150 | 4 pcs reactors in paralleled | 7.5KV |
400KV Power Cable | 220 | 2 pcs reactors in series, then two groups in parralled | 15kV |
400kV GIS | 512 | 4 pcs in series | 30kV |
