Tool/software:
Hi, I have a question regarding the Lab4 setup and inrush current protection.
In the lab procedure, it mentions:
Slowly ramp up the DC bus voltage to 800V
Ramp the AC grid voltage to 230Vrms (L-N), i.e. 400V L-L
Then write "1" to TINV_allRelaySet as soon as the voltage reaches 230Vrms, to avoid overheating the inrush current limiting resistor (47Ω)
To avoid damaging the AC source, I instead used the three-phase utility grid. However, in my test, even though I set TINV_allRelaySet = 1 within 1 second after turning on the grid, the 47Ω resistor still burned out.
So I would like to ask:
1. Is it acceptable to set TINV_allRelaySet = 1 before turning on the AC grid power?
2. Is it really necessary to slowly ramp the grid voltage to 230Vrms? Or is it safe to connect directly to the utility grid (400V L-L)?
Thanks.
