Modification of DRV8301-69M-KIT Voltage Feedback Circuits (Its VdcBus_kV Value is wrong.)

ay0689_3

Other Parts Discussed in Thread: DRV8301-69M-KIT, DRV8301, MOTORWARE

Hello, I would like to modify the voltage feedback circuits on DRV8301-69M-KIT to fit the voltage range for my DC24V Motor.

I understand that Originally DRV8301-69M-KIT is set to operate DC48V motor according to SPRUHJ1E.

	DC48V Motor	DC24V Motor
Vmax	66.3V	31.07V
R	95.3K Ohm	42K Ohm

I modified R60,R61 and R63 to 42KOhm resisters as above UG mentioned. And I modified one parameter in the user.h file as follows.

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#define USER_IQ_FULL_SCALE_VOLTAGE_V (24.0) // 24.0 Example for drv8301_revd typical usage and the Anaheim motor

//! \brief Defines the maximum voltage at the input to the AD converter

//! \brief The value that will be represented by the maximum ADC input (3.3V) and conversion (0FFFh)

//! \brief Hardware dependent, this should be based on the voltage sensing and scaling to the ADC input

#define USER_ADC_FULL_SCALE_VOLTAGE_V (31.07) // 66.32 drv8301_revd voltage scaling

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After setting these values, I complied the lab02c project and executed the code.

The following screen captured image is the result.

Best regards,

ay0689

over 9 years ago

0 Adam D. Reynolds over 9 years ago

Guru 12800 points

ay0689,

The reason that the VdcBus_kV value seems strange is because it now has a different USER_ADC_FULL_SCALE_VOLTAGE_V than your phase voltage inputs.

The MotorWare software assumes that the phase voltage and the dc bus measurement have the same voltage divider.

There are 2 solutions to this issue:

1. Replace R35 with the 42K resistor you used for R60, R61, & R63. This will align the voltage divider for the Vdc bus to the phase voltage measurements.

2. Modify the software in hal.h so that the Vdc bus measurement does not use the same scale factor as the pase voltage measurement. The function you want to change is HAL_readAdcData.