I have an OTS BLDC motor controller as well as one that I just made myself and both seem to be dramatically slower at higher frequencies. When I look at how much current is being drawn it makes sense, but it does not make sense otherwise.

I have two tests:

1. 20% duty cycle, f_PWM = 3kHz draws about I = 0.8A from power supply
2. 20% duty cycle, f_PWM = 8kHz draws about I = 0.25A from power supply

This is particularly bad because I want to drive the motor at f_PWM ~30kHz.

To be honest, these tests were done with my controller which is limited from ever getting to 100% duty cycle so that I will never have any crossover that could lead to shoot-through. That said, I do NOT think the losses are switching losses (the current is also much lower).

Any ideas or common reasons why?

Thanks in advance