Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage test device). Next, we will share with you the introduction of capacity verification of series resonance device.

Device capacity verification

The device has a capacity of 75kVA and is divided into three sections of reactors, with a single section of 25kVA/25kV/1A/110H.

Verification:

1. 10kV/400mm2 cable 1km AC withstand voltage test, capacitance ≤ 0.4213uF, test frequency 30-300Hz, test voltage 22kV, test time 5min.  

If three reactors are connected in parallel, L=110/3=36.7H, then:

Test frequency: f=1/2 π√ LC=1/(2 × 3.14 × √ 36.7 × 0.4213 × 10-6)=40.48Hz

Test current: I=2 π fCU Test=2 π × 40.48 × 0.4213 × 10-6 × 22 × 103=2.36A

2. AC withstand voltage test for 400m of 35kV/400mm2 cable, capacitance ≤ 0.0858uF, test frequency 30-300Hz, test voltage 52kV, test time 60min.

Use three reactors in series (mutual inductance coefficient 1.2), L=110 × 2 × 1.2=264H

Test frequency: f=1/2 π√ LC=1/(2 × 3.14 × √ 264 × 0.0858 × 10-6)=33.44Hz

Test current: I=2 π fCU Test=2 π × 33.44 × 0.0858 × 10-6 × 52 × 103=0.94A

3. AC withstand voltage test for 35kV/350kVA power transformers, capacitance ≤ 0.01uF, test frequency 45-65Hz, test voltage not exceeding 68kV, test time 1min.  

If three reactors are connected in series (with a mutual inductance coefficient of 1.2), L=110 × 3 × 1.2=396H, and a compensating capacitor of 80kV/10000pF is added

Then:

Test frequency: f=1/2 π√ LC=1/(2 × 3.14 × √ 396 × 0.02 × 10-6)=56.55Hz

Test current: I=2 π fCU Test=2 π × 56.55 × 0.02 × 10-6 × 68 × 103=0.48A

Meet the experimental requirements.