ISO5500 GATE DRIVE FOR 690VAC SPEED DRIVES AND INVERTERS

Hi Javier,

You need to examine the gate charge requirement of your IGBT's. It's basically a question of how quickly the driver can charge up the gate capacitance. The ISO5500 provides a peak current of 2.5A, so depending on timing requirements you may need to adjust the blanking capacitor for DESAT. This is explained further in the datasheet, on pages 23-25.  

That being said, the rated working voltage is 1200V, so if you have 1700V going through the IGBT, that would exceed the isolation rating. 

I hope this helps,
Jason Blackman 

Hi Jason,

we are going to use ISO5500 with a push pull buffer in order to charge the gate capacitance quickly (2.5A is not enougth).

Regarding 1700V IGBTs, usually the bus voltage is 1000V but sometimes, the bus voltage can arrive to 1250V (short time, during regeneration).

Can this be a problem?

Best regards,

Javier Rey

Hi Javier,

The maximum working voltage of the ISO5500 is 1200Vpk. Can you tell me about the voltage when the bus goes to 1250V? Is it a peak value? For how long?

Thanks,
Jason Blackman 

Hi Jason,

1250V is the maximum DC voltage between Collector and Emiter of the IGBT. We use a three phase rectifier to get a DC voltage (bus voltage), then we use a three phase IGBT inverter to control a motor. Usually, the maximum working voltage is 1000V (DC voltage) but if the motor is decelerating, the DC voltage can arrive to 1250V.

Thanks & regards,

Javier Rey