CCS:TMS320F280049CPMS

Janusz Michniowski

Other Parts Discussed in Thread: TMS320F280049C

Tool/software: Code Composer Studio

I made a design of an inverter with a processor: TMS320F280049CPMS.

1-
What is the maximum rotation frequency on this processor ...?

2-
Do you need to modify three RC filters of three phases that the processor measures ...?
Now I have a resistor with phase = 100k and a 100nF capacitor and a 6k resistor to ground. Is it possible to reduce the capacitor 100nF and to what the lowest value to correctly measure the phase voltage ...?

3-
I used PWM = 20kHz
I need a motor rotation frequency of 1200Hz.
Is this frequency possible and do I have to modify the phase voltage filters ...?

over 4 years ago

0 Ramesh Ramamoorthy over 4 years ago

TI__Mastermind 27240 points

1. The processor clock frequency is 100MHz

2. Someone of us will get back to you on this

3. With 20KHz, 1200Hz sine wave will give very course resolution (about 15 updates per cycle) and there will be a bit of speed oscillations.

0 Janusz Michniowski over 4 years ago in reply to Ramesh Ramamoorthy

Prodigy 50 points

1-
Yes the clock is 100MHz

2-
OK.

3-
Will increasing the PWM, for example at 40kHz, increase the number of actuations and improve the stability at 12000Hz revolutions ...?

0 Ramesh Ramamoorthy over 4 years ago in reply to Janusz Michniowski

TI__Mastermind 27240 points

Yes, but the inverter should be capable of switching at 40KHz.

0 Yanming Luo over 4 years ago in reply to Ramesh Ramamoorthy

TI__Guru** 115500 points

Answer to question 2 and 3.

2. You can select suitable resistance according to the maximum voltage of the motor, and select the capacitance to ensure the voltage filter frequency is between 300~800Hz. You may refer to chapter 5.2 (Hardware Prerequisites) of InstaSPIN-FOC and InstaSPIN-MOTION User's Guide (Rev. H) (http://www.ti.com/lit/ug/spruhj1h/spruhj1h.pdf) that has a detailed description of this.

3. Yes, you might use a higher PWM frequency for the high-speed motor as you mentioned above, but the control/ISR frequency should be less than the 20kHz limit to the CPU bandwidth.

0 Janusz Michniowski over 4 years ago in reply to Yanming Luo

Prodigy 50 points

I'm glad you respond quickly. I've been working on an electric surfboard project for the second year now.

My product is 50V and 250A.
I need to reach 12,000 rpm on a motor with 6 pole pairs = 1200Hz.

What version of the processor do you recommend to work stably with FOC at 1200 Hz ...?
Should I use a different type of processor with a higher clock ...?
What's faster?

0 Yanming Luo over 4 years ago in reply to Janusz Michniowski

TI__Guru** 115500 points

TMS320F280049C should be ok for your application. You can use the 20~25kHz control frequency, and implement 2~3 times PWM frequency of the control frequency like 60~75KHz. We have run such low inductance and high-frequency motor on this controller with InstaSPIN-FOC, the maximum frequency can be up to 1400Hz.

You might take a look at the link below.

https://e2e.ti.com/support/microcontrollers/c2000/f/171/p/921747/3480058#3480058

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CCS:TMS320F280049CPMS