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TMDSHVMPPTKIT: DC/DC boost with MPPT and charge controller

Nelson Koch
Prodigy 10 points

Part Number: TMDSHVMPPTKIT

Hi,

In the scope of a research project, we are working on the implementation of a demonstrator for an application of VIPV (vehicle integrated PV).
In this project, we would like to do the coupling of a PV module to a high voltage lithium-ion battery using one or multiple development kits.

The specifications of the power converter will be the following.

  • Input :
    • Voltage : ~30-70Vdc
    • Power : ~50-150W
    • Control : MPPT
  • Output :
    • Voltage : ~350-400V
    • Power : ~50-150W
    • Control : charge controller (constant current - constant voltage)
  • Galvanic isolation between input and output


We have been looking at the different kit offered by TI and we've found the TMDSHVMPPTKIT which seems to be the closest to the use we would like to make of it.
There are however the following two limitations:

  • Input voltage : The input voltage range of the kit (200-300V) is to high compare to our application.
    • Could we adapt the board to suit a higher voltage?
    • Could we add a DC/DC boost in between to set up the voltage of the PV module?
  • Output control : The output is regulated in constant voltage. However, a constant current control would be needed as a first phase of charging.
    • Could this easily be implemented in software?
    • What would happen with the current software implementation of the kit if the voltage regulated by the converter is set higher than the one of the battery to which it is connected? Would we reach a constant maximum current (we would therefore automatically have our current control) or would an alarm be triggered?

Thank you for your support!

Best regards,

Nelson

  • 0
    TI__Mastermind 26811 points

    Hi Nelson,

    We are reviewing your query and will get back to you asap.

  • 0
    TI__Genius 11215 points
    • Could we adapt the board to suit a higher voltage?

    The boost inverter in the board is 200Vin and 400Vout. So you need to make necessary changes in this board to make it suitable for 30V~70Vin and 400Vout. We have another design  at

    https://www.ti.com/tool/TIDM-SOLARUINV

    This one is 30~50VDCin and has two power stages. The first stage boost the voltage to 40VDC. Then the next stage generates 120Vac/220VAC from this 400VDC.

    • Could we add a DC/DC boost in between to set up the voltage of the PV module? =========>Yes, you can do that. 

    Output control : The output is regulated in constant voltage. However, a constant current control would be needed as a first phase of charging.

    • Could this easily be implemented in software============> yes, you have to change the voltage control loop to a current control loop. The current control loop will regulate the charging current.

    • What would happen with the current software implementation of the kit if the voltage regulated by the converter is set higher than the one of the battery to which it is connected? Would we reach a constant maximum current (we would therefore automatically have our current control) or would an alarm be triggered?

    If you connect to a battery you have to use a current controller first. Then when the battery is almost charged you can switch to voltage mode again. This particular design was done for working with a downstream DC/AC inverter which will do the current control. So, we did not need current control in the DC/DC stage.

  • 0 in reply to Shamim Choudhury
    Prodigy 10 points

    Hi Shamim,

    Thank you for this detailed answer! I would have some more questions though:

    Shamim Choudhury said:
    The first stage boost the voltage to 40VDC
    • I guess that you meant 400VDC for the DC bus of the TIDM-SOLARUINV kit, right?
    • If it the case, would that be feasible to adapt its controller to implement a current control loop on the DC bus? We will then bypass the whole inverter stage and only use its DC/DC flyback stage. How complex would this implementation be?
    Shamim Choudhury said:
    Could we add a DC/DC boost in between to set up the voltage of the PV module? =========>Yes, you can do that.
    • Would you have any standard TI design to suggest for such a module?
  • 0 in reply to Nelson Koch
    TI__Genius 11215 points

    Yes, DC bus volt is 400V. 

    Yes, you can bypass the inverter. Just do not use the code related to the inverter. This should not be complex for you

    No, we do not have a standard TI design. These TI designs are there to illustrate the application of C2000 MCU in any power converter. TI do not design any standard module like you are asking for.