Dear Forum,
I have a 3 phase servo motor with seimens.
In its invertor stage, there are 3 IGBT modules each have two one for upper and the other is for low side.
The invertor out put phases are U,V and W
IGBT on low side for V phase has been shorted thrice a time.
On inspection I have found gate drives for these 6 IGBTs which are optically isolated from controller. 5 optocouplers give reading on diode test of 1.5 V
but the one for low side of V phase has a reading of 1.002V.
Motor insultation is OK with the help of Meggar.
Problem is inside drive. Is that could be the reason (optocoupler)
Please guide in this regard.
Wahid Bashir
I have a 3 phase servo motor with seimens.
In its invertor stage, there are 3 IGBT modules each have two one for upper and the other is for low side.
The invertor out put phases are U,V and W
IGBT on low side for V phase has been shorted thrice a time.
On inspection I have found gate drives for these 6 IGBTs which are optically isolated from controller. 5 optocouplers give reading on diode test of 1.5 V
but the one for low side of V phase has a reading of 1.002V.
Motor insultation is OK with the help of Meggar.
Problem is inside drive. Is that could be the reason (optocoupler)
Please guide in this regard.
Wahid Bashir