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Request for pointers for developing 40kW VFD for Dynamometer

Other Parts Discussed in Thread: TIDA-00366, ISO5852S, TIDA-00195, TIDA-00448, TIDA-00912, TIDA-00914

Greetings. I am trying to find some motor control reference designs with the aim of getting to a custom VFD design for a dynamometer that will be powered by an AC 3-phase induction motor, upto a level of about 40kW.  There is a bewildering array of reference designs and development boards just on the TI website -  InstaSPIN, DesgnDrive, Stellaris, etc. that go upto about a kW. Would it be a good idea to choose one of these and scale it up to 40kW by changing the power module and possibly parallelizing the output as has been done for the low-voltage 5kW Forklift traction motor design? Apart from using optoisolators and upgrading the power modules what else would I need to take care of for functional completeness (safety and EMI issues apart)?

I know this is pretty vague at the moment so I am not asking for too much detail.  Any broad pointers to help sharpen my focus would be greatly appreciated. Thanks very much!

Best - Ram

  • Do you have any experience developing multi kW inverters? It is no small feat.

    We don't offer designs for this sort of power level because it's non-trivial and most people who want this sort of level usually are vastly more qualified to design one than TI.

    you aren't going to find typical power modules that we use for small kW references at this power level, most designs are discrete IGBT or pre packaged IGBT solutions specific for these types of markets / power levels.
  • Hi Chris,

    Thank you for your reply and words of caution which I agree with completely.  Let me sharpen the question a bit. Let me look purely at the schematic/BOM level, and look at the system as consisting of 2 core parts - the control module and the power module. Noting that an appropriate power module must be custom-designed, would it be appropriate to think of taking a TI power control module and slapping on a custom-designed power module (with an isolation layer) to get to the desired solution, at least at a schematic level? Or would that not be an appropriate way to look at it at all?

    Best - Ram

  • "would it be appropriate to think of taking a TI power control module and slapping on a custom-designed power module (with an isolation layer) to get to the desired solution, at least at a schematic level?"

    Yes, this is a very appropriate - and most common - way to handle

    I've sent this thread to some colleagues on our TI wide system teams to see if they want to contribute as well

  • Thank you Chris, that helps very much! Now given the bewildering variety of motor driver reference designs + development boards available, which would be the most flexible one in terms of (i) being parametrizable and (ii) allowing easy modification / refinement of the control algorithms? We would also need to handle about 350kW of braking. I also see a 10kW TIDA-00366 from 2016 apart from what I listed above. What would be the appropriate ref design or purchasable development board to start with - again, just at a schematic level?

    Best - Ram

  • I've sent this thread to some colleagues on our TI wide system teams and expect them to respond.

  • Just marking this as unresolved just in case it gets in the way of someone responding to the last post about which board to choose!
  • Hello Dr. Ramkumar Ramaswamy,

    I apologize for the late response. With regards to TI example designs for 3-phase inverter power stages we have multiple TI designs capable driving IGBTs 10kW or higher, depending on selection of a suitable IGBT or IGBT module. Let me start what we have with some example TI designs and add a key feature for each. All these designs are done to offer a direct interface to a C2000 MCU for control.
    The 350kW of braking is quite a lot. Are you even planning to add an active front end to feedback energy back to the grid?

    The TIDA-00366, you refer to was designed t support up to 10kW and 50A peak phase current and includes phase current and DC-link voltage sensing with reinforced isolated amplifiers. It offers an interface to a C2000 MCU Launchpad and might be a good start. To scale for higher power, please see below.

    Option 1
    Key feature: Short-circuit and shoot-through protection through reinforced smart gate driver with Miller clamp, UVLO, DESAT and soft shutdown (TI gate driver ISO5852S)
    Proposed TI design: TIDA-00195 Isolated IGBT Gate Driver Evaluation Platform for 3-Phase Inverter System. This design has been tested up to 22kW, but does not incorporate I-V sensing. It can be scaled to IGBT modules up to 150A. This design also includes a brake IGBT for resistive braking, but it would need to be scaled to handle 350kW peak pulse power.
    URL: Please refer to

    Option 2
    Key feature: Designed for medium power IGBT modules rated current up to 1000 A and Qg up to 10 uC, common MOSFET footprint enables to choose parts with 25 A, 32 A and 40A rating for flexible source and sink currents. Programmable DESAT and soft shutdown feature.
    Proposed TI design: TIDA-00448 Flexible High Current IGBT Gate Driver with Reinforced Digital Isolator Reference Design
    URL: Please refer to

    For phase current sensing up to 100A peak, I'd actually recommend using our delta-sigma modulators AMC1303, AMC1304, AMC1305 or AMC1306 which offer +/-50m full-scale range, e.g. with a 0.5mOhm shunt you can get +/-100A peak current range. For higher currents up to 200A we offer a solution with pre-amplifier, please see TIDA-00912: Shunt-Based High Current Measurement (200-A) Reference Design with Reinforced Isolation Amplifier. URL:

    To learn more about the performance and design guidelines with our delta-sigma modulators AMC130x you can refer to the TI design: TIDA-00914 Reinforced Isolated Phase Current Sense Reference Design with Small Delta Sigma Modulators.

    All TI designs come with schematics, layout and garner files and the TI design guide provides information on the hardware design as well a test results.

    Does this answer your question on hardware?

    Martin Staebler
  • Dear Martin,

    Many thanks indeed for your detailed reply and roadmap! Good to know that the TIDA-00366 will make for an appropriate start, and with the specifics you have provided on Options 1 & especially 2, I think we have a clear action plan to work on. Not that this power level will be without challenges of course, as Chris has warned, and we still need to figure out how best to handle the braking power (feeding it back to the grid may not be an option that will be always present in our given context unfortunately).

    So now to dig into the material you have so kindly referred me to, and will be back with specific questions as things progress.

    Thanks again!

    Best - Ram