running motor with lower impedences

[jneely]

Posted on June 30, 2003 at 16:24

running motor with lower impedences

[jneely]

Posted on May 17, 2011 at 10:16

I am using the sample stmicro code as a basis for 24v and 300v motor controller with the st72141K . The software is the same between designs, but the hardware is slightly different to allow for the different voltages. I am having trouble with the 24v motor starting using the 24v board. I am able to get the 300v motor to spin up no problem, so I know the hardware is working. I suspect that the lower resistance/inductance of the 24v motor is the cause of problem as the sample code we have was design for the 300v motor. I have tried modifying the ramp table, but have had no luck. The 24v motor will try to start. It appears to make it through alignment then stops and tries again. The resistance of the 24v motor is about 8 times less than the 300v motor. I am thinking I need to adjust the ramp tables and/or the pwm frequency. Any ideas? All help is greatly appreciated.

Thanks.

[stephanie2]

Posted on May 17, 2011 at 10:16

Hello,

Can you describe more precisely what happens at start-up with your 24V motor? When you said ''It appears to make it through alignment then stops and tries again'', do you mean that after alignment, it is doing an other alignment again? Also, where did you get your code from, are you using a Kanda kit? In this case, the code has been fine tuned for a low voltage motor and not for a 300V motor. You can try to modify the start up ramp but also the delay coefficient parameter. This parameter is also very important at start-up. Best Regards

[jneely]

Posted on May 17, 2011 at 10:16

As it turns out, there was a hardware problem with the current sensing feedback. The motor will now start up without problem. Thanks for the help though.