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TMS320F28069: Lab 3A Motor will only run at half its rated speed.

Part Number: TMS320F28069

I was able to identify my motor with lab 2c, but when I try to run the motor up to speed, I am seeing my PWM going to my gate drivers max out at roughly half the motor's rated speed.
The motor is rated for 180 Hz.

My current probe is showing me that the maximum I can get out is roughly 95 Hz or around 1800 RPM in my watch window.

I did use a tachometer and I did confirm that the read speed is correct, but I cannot command full speed of the motor.

Lab10a does help as I can get to 2200 RPM, but I need to get to the full rated value of the motor at 3600 RPM or 180 Hz.

Lab5a and 5b make the signal cleaner, but do not help with increasing the speed either.

Here's my current probe.

  

Here's phase A positive and negative PWM.

Currently I have the deadband for my PWM set at 1µs, but I have a feeling that's much too high.

PWM frequency for this motor is 10kHz with no dividers.

Here's what my MOSFET data sheet tells me. Should I set this down closer to 200ns?

The compressor I have is rated for 24-36V. My bus voltage is 48V.

Here's the header file:45041.user.h

It seems to me that my flux is wrong, and I'm running out of voltage for the motor to use, but the ID flux is about 0.24 V/Hz

My full scale IQ_Freq is 200 Hz.

48V/0.24 gives 200 Hz.

I am not seeing any motor instability, but I cannot push the motor past half speed.

  • I took a look at voltages on the phases, and realized that this motor needs more voltage to get to a higher speed. I turned up the voltage from 48V to 55V, and sure enough I was able to get more 300 more RPM from the motor. I can't go any higher due to design restrictions, but it's good to know for later.