Hello,

I am looking to implement a "soft start" solution on a DC starting motor and I am running out of ideas. The motor itself is capable of drawing a maximum 2000A @ 70VDC (very short period of time mind you), and therefore I am limited to the components that I can use. I originally thought an IGBT with PWM might work but cannot find much information on controlling the power in a smooth manner (to essentially limit the in rush current).

Any ideas?

Thanks!!

 

That idea may work and you could play with the curve as needed but with low frequency pwm, the current event may still take place on the first pulse. I would start with an small inductor if the inrush time is very short and see what the motor does. It may be that the inrush is short _because_ you can source 2000A. A few turns of the motor lead around a suitable core may be all you need and it's much cheaper.

Regards
cww