Hi,

I have a problem with my h bridge. Please check the h bridge picture.
My DC bus is 80 V DC.
When I begin swithing 5KHz PWM, at the middle of the PWM period a voltage appears, it oscillates about 7-8 VDC. (Please check the pictore Mosfet Switching)
I have IR2101 gate driver and I could not understand and find the reason why this PWM has extra voltage!!! Due to dc motor inductance....?

Please help me...

Max

 

There is not enough of the circuit shown to make any determination.

 

You are right, I added h bridge schematics.

 

No component values. The speed-up diodes might do better in parallel with one of the resistors, and eliminate the other. For instance, in parallel with R11, no R12.