Help selecting right instra spin platform

Hi Carlos,

I would like you to check this link in shortlisting the device according to your application: http://www.ti.com/ww/en/mcu/instaspin/index.shtml?DCMP=c2x-instaspin&HQS=instaspin

Carlos Silva79 said:

Is there any model of CPU that I should aim for or will the 28027 be enough?

This totally depends on the peripherals you'll be using and the computation power you require. Do compare the datasheets of F28027F and F28069F; the major difference being 27F has a fixed point unit and 69F has a floating point unit & a CLA.

I'm also forwarding this post to the Instaspin Guru, who will also guide you in the right direction.

Regards,

Gautam

any of the InstaSPIN enabled devices will do the job for the motor control. You will select based on other needs: packae size, memory, peripherals, other I/O, price, etc.

http://www.ti.com/ww/en/mcu/instaspin/instaspin-foc_MCUs.shtml

SPRUHJ1 is the main User's Guide with information on the hardware requirements. Also review relevant EVMs/Kits for examples.  If you install MotorWare and run MotorWare.exe it will act as a guide to all available resources.

You can add a controlCARD or Launchpad interface onto your power stage if you like....some do that just for ease during development.  Personally I wouldn't do it if you are already familiar with your power stage. Better to get as close to the final layout as possible and deal with any feedback/layout issues as early as possible.

Thank you for the clarifications

In your opinion, is the 9PPR/Hz (18PPR per shaft rev, being a 4 pole motor) encoder we already have installed  a suitable feedback or will performance be improved using texas own sensorless aproach? The motor is required to operate with maximun torque from 0RPM to nameplate speed and constant horsepower up to 4000RPM (4 pole, ~150Hz)

Regards

In very high frequency applications (2 KHz+) you need to run the estimator and current controllers faster. So having more MIPS is a benefit with the 90 MHz. 

Your sensors may help with full load startup, but once the rotor is moving our sensor less observer will give superior resolution. Let me think about this a little more....

We currently use a PWM frequency ranging from 2 to 4KHz, which is actually quite slow, when compared to small consumer products that run at 20+Khz. Is this what you are refering?

In our application, the hall sensors are installed on the output of the IGBT's. With current being sampled when the low switches are active. I am assuming the same should be valid here, but would be gratefull if you could clarify.

Carlos Silva79 said:

We currently use a PWM frequency ranging from 2 to 4KHz, which is actually quite slow, when compared to small consumer products that run at 20+Khz. Is this what you are refering?

I was referring to the frequency of the control and estimation loops, but they are always <= the PWM frequency.

Carlos Silva79 said:

In our application, the hall sensors are installed on the output of the IGBT's. With current being sampled when the low switches are active. I am assuming the same should be valid here, but would be gratefull if you could clarify.

yes, that works fine. You can also try over-sampling and averaging the current, but it probably won't help much with your motor.  what you want is the average current of the motor in the control cycle.  taking it at the midpoint of a low-side switch event can typically be used for motors with higher inductance and steady current decay.

OK, I ordered a launchpad board with an F28027F CPU to start prototyping

A few questions:

How do i get started with the software? I downloaded and run motorware, but have no idea how to start using it. I assumed it would be something similar to ST motor control application.

Second question: Can I use this same hardware to implement IM open loop scalar control with space vector modulation on more simple systems such as fans, etc?

Regards

Carlos Silva79 said:

How do i get started with the software? I downloaded and run motorware, but have no idea how to start using it

C:\ti\motorware\motorware_1_01_00_13\docs\labs\instaspin_labs.pdf

there is a post on the InstaSPIN Forum that outlines how to get started

http://e2e.ti.com/support/microcontrollers/c2000/f/902/t/287352.aspx

Carlos Silva79 said:

Second question: Can I use this same hardware to implement IM open loop scalar control with space vector modulation on more simple systems such as fans, etc?

Hardware, yes.  We haven't released any software projects in MotorWare for open loop scalar (why do that when you have everything to do FOC?) but we actually have implemented in before to do some testing.  It's very simple to update the ctrl.c/ctrl.h  file to bypass to do this...I can probably share the files I've used (tested on the TMDSHVMTRINSPIN kit)

At the moment we have a open loop controller which is controlled by a separate MCU.

We designed that way as the controller itself could be used on "dumb devices" while the separate MCU board and additional hardware (Current sensors, voltage transducers, etc) could be implemented for high performance devices that required closed loop operation.

At the moment these are the issues we are having with the texas instruments platform:

No sample code: I need something that just basically works to demonstrate the concept and can later be changed to meet our specific criteria

No schematics showing what pins connect to what, so i have no idea how to interface our existing hardware.

Is this something that can be provided? Regards

Carlos Silva79 said:

No sample code: I need something that just basically works to demonstrate the concept and can later be changed to meet our specific criteria

there is plenty of sample code in MotorWare (InstaSPIN-FOC and InstaSPIN-MOTION) and in controlSUITE (see the projects at: C:\ti\controlSUITE\development_kits\HVMotorCtrl+PfcKit_v2.1 )

If you want to do scalar control in MotorWare I just mentioned that it's pretty simple to do and I could probably give you some new ctrl.c/.h files for InstaSPIN-FOC projects.

Carlos Silva79 said:

No schematics showing what pins connect to what, so i have no idea how to interface our existing hardware.

You said you installed MotorWare and ran MotorWare.exe

there are links to all the HW schematics for the inverters, which use a controlCARD interface. The "work" is then taking that controlCARD interface and mapping back to the specific MCU which is on the card. But all the information is right there.

For example, on the High Voltage Kit the links point you directly to:

C:\ti\controlSUITE\development_kits\HVMotorCtrl+PfcKit_v2.1\~HVMotorCtrl+PFC-HWdevPkg\HVMotorCtrl+PFCKit-R1.1

Thank you for pointing me in the right direction, Chris.

I am new to the TI stuff, therefore I am taking a while to understand how to set up and do something useful. Would you be so kind as to send me/attach those files you mentioned and some instructions on what needs to be changed?

Also, regarding software, so far I have downloaded Motorware and control suite. Is there any other package I need to download to get started? Which compiler can I use?

Kind Regards

Carlos Silva79 said:

I am new to the TI stuff, therefore I am taking a while to understand how to set up and do something useful. Would you be so kind as to send me/attach those files you mentioned and some instructions on what needs to be changed?

if you have controlSUITE installed you have all the files I mentioned above.

"what needs to be changed"

to do what exactly?  I don't know what you want to do. If you want to do an open loop induction motor control I can probably help you get that working, but I recommend first going through the MotorWare InstaSPIN Projects & Labs User's Guide and understand the capability and the source code.  To do open loop control you are going to update the ctrl.c and .h files to bypass the forward FOC operations.

Carlos Silva79 said:

Also, regarding software, so far I have downloaded Motorware and control suite. Is there any other package I need to download to get started? Which compiler can I use?

You will need to download Code Composer Studio v6 Integrated Development Tools

there is a free version to use with XDS100 branded emulators (which all of our C2000 MCU tools include)