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TMS320F280025C: Limit power drawn by motor

prashanth dodla
Prodigy 20 points

Part Number: TMS320F280025C

Tool/software:

Hello,

We are working on solar power pump design based on based on TMS320F280025C and universal motor control lab, we need help with one issue.

We are controlling the speed of the pump based on MPPT of solar panel and the pump is able to operate at optimal MPPT point, but when sudden load is applied the panel voltage is dropping quickly trigging under voltage protection.

We are able to detect the drop in panel voltage and trying to adjust the reference speed to match the available power but before the speed is reduced under voltage is condition is triggered. 

Is there a way to quickly reduce the current drawn by motor to avoid folding of solar panel voltage or is it advisable to set current limit.

  • 0
    TI__Mastermind 45606 points

    Hi,

    Setting a current limit of the Speed PI such that the voltage doesn't dip sounds reasonable. You may also need to tune your Speed PI and current PI so they react quickly enough.

    prashanth dodla said:
    We are able to detect the drop in panel voltage and trying to adjust the reference speed to match the available power but before the speed is reduced under voltage is condition is triggered. 

    This idea could work as well, but the reduction in current output maybe needs to happen more quickly.

    Best,

    Kevin

  • 0 in reply to Kevin Allen18
    Prodigy 20 points

    Hi Kevin,

    Thank you for the reply, I will try setting current limit in Speed PI. 

    As you pointed out the response of current and speed PI is slow. We will try tuning controllerrs for faster response but we will keep current limit in speed PI as backup just in case.