BOOSTL-DRV8305EVM: Abnormal Torque Output at Current > 20A

user4708725

Other Parts Discussed in Thread: MOTORWARE, DRV8305, CSD18540Q5B, BOOSTXL-DRV8305EVM

The software path I used: motorware_1_01_00_18\sw\solutions\instaspin_foc\boards\boostxldrv8305_revA\f28x\f2806xF\projects\ccs\proj_lab10a

The BOOSTXL-DRV8305EVM is a 15A, 3-phase brushless DC drive stage based on the DRV8305 motor gate driver and CSD18540Q5B NexFET™ power MOSFET.

4.4V to 45V voltage supply input
Supports up to 20A peak, 15A continuous current ouput

Now I have made a circuit board imitating BOOSTL-DRV8305EVM, which enlarges the driving power of the motor driving circuit. The power device of the driving motor can withstand 50A current.

When USER_MOTOR_MAX_CURRENT > 20A is set, a large enough load is applied to the motor. At this time, the nFAULT alarm occurs, the red light on the driving board is on, and then the motor has no torque output.

When USER_MOTOR_MAX_CURRENT < 20A is set, a sufficient load is applied to the motor, and the motor's torque output is normal.

1. I use the official network supporting procedures, now USER_MOTOR_MAX_CURRENT is limited to 20A,I need the current of the motor in 35A for my product.

which code should be repaired in the program to increase USER_MOTOR_MAX_CURRENT to 50A, and no nFAULT alarm occurs.

2. Is it possible to modify the following two codes?

#define USER_IQ_FULL_SCALE_CURRENT_A (24.0) // BOOSTXL-DRV8305EVM = 24.0 A

#define USER_ADC_FULL_SCALE_CURRENT_A (47.14) // BOOSTXL-DRV8305EVM = 47.14 A

3. My problem is relatively simple. using the circuit board I made.When USER_MOTOR_MAX_CURRENT > 35A, the output of motor torque is normal,and no nFAULT alarm occurs.

over 7 years ago

0 Yanming Luo over 7 years ago

TI__Guru** 117260 points

1. The EVM board can't support such high current, the ADC will be overflow since the peak phase current is defined to (USER_ADC_FULL_SCALE_CURRENT_A/2.0). You have to redesign the board to support such high current, please refer to Chapter 5.2 of InstaSPIN user's guide ((SPRUHJ1H) http://www.ti.com/lit/ug/spruhj1h/spruhj1h.pdf) to design the current feedback circuit.

2. The USER_ADC_FULL_SCALE_CURRENT_A depends on the hardware, you can't change it if the hardware is fixed.

3. As mentioned above, you need to change the hardware board to increase the maximum sampling current at the ADC.

Btw, you may have a look at the DRV8305 datasheet that will help you to understand why the nFAULT generate and how to change the register to increase the protection current value.

0 user4708725 over 7 years ago in reply to Yanming Luo

Expert 1030 points

I have redesigned the hardware. I am very sure that the new hardware can withstand 50A continuous current. I also took a picture in my questioning.
The problem now is that the new hardware uses official network programs, and the software limits the current of my motor to 20A,When USER_MOTOR_MAX_CURRENT > 20A is set, a large enough load is applied to the motor. At this time, the nFAULT alarm occurs, the red light on the driving board is on, and then the motor has no torque output.

1. My redesigned hardware fully meets the requirements of 50A.When USER_MOTOR_MAX_CURRENT > 35A, the output of motor torque is normal,and no nFAULT alarm occurs.How can the software be modified to meet the requirements?

2.My redesigned hardware fully meets the requirements of 50A.How to configure the drv8305 register to increase the current protection to 50A?

0 Yanming Luo over 7 years ago in reply to user4708725

TI__Guru** 117260 points

1. Select the appropriate device supported InstaSPIN-FOC, design the current and voltage sensing circuit based on the specification of motor, select the appropriate current shunt resistor/current sensor and its amplify gain, voltage feedback circuit and voltage filter.

You may refer to the motor control EVM kit supported instaSPIN-FOC as the following post.

How To Evaluate and Develop with InstaSPIN-FOC and InstaSPIN-MOTION

https://e2e.ti.com/support/microcontrollers/c2000/f/171/p/287352/1949070

And you may have a look at Chapter 5.2 (Hardware Prerequisites) of InstaSPIN-FOC and InstaSPIN-MOTION User's Guide.

http://www.ti.com/lit/ug/spruhj1h/spruhj1h.pdf

2. Set correct parameters based on the hardware board in user.h, the calculation equations can be found in Chapter 5.2 (Hardware Prerequisites) of InstaSPIN-FOC and InstaSPIN-MOTION User's Guide as well.

#define USER_IQ_FULL_SCALE_VOLTAGE_V (24.0)

#define USER_ADC_FULL_SCALE_VOLTAGE_V (66.32)

#define USER_IQ_FULL_SCALE_CURRENT_A (41.25)

#define USER_ADC_FULL_SCALE_CURRENT_A (82.5)

#define USER_VOLTAGE_FILTER_POLE_Hz (335.648)

3. Change the sign of the current coefficient in HAL_readAdcData() in hal.h, you may refer to chapter 5.2 of InstaSPIN-FOC and InstaSPIN-MOTION User's Guide that has a detailed description of this also.

static inline void HAL_readAdcData(HAL_Handle handle,HAL_AdcData_t *pAdcData)

{

_iq current_sf = HAL_getCurrentScaleFactor(handle);

}

4. And then you can follow the instaSPIN lab guide to use lab01b and lab01c to verify your hardware. And you may refer to below FAQ posts.

TMS320F280049C: Can't get motor running with INSTAspin FOC identification on my own circuit board.

https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/788800

CCS/LAUNCHXL-F28069M: Can I use InstaSPIN-FOC with my on driver board?

https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/561565

static inline void HAL_readAdcData(HAL_Handle handle,HAL_AdcData_t *pAdcData)

{

_iq current_sf = HAL_getCurrentScaleFactor(handle);

}

4. And then you can follow the instaSPIN lab guide to use lab01b and lab01c to verify your hardware. And you may refer to below FAQ posts.

TMS320F280049C: Can't get motor running with INSTAspin FOC identification on my own circuit board.

https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/788800

CCS/LAUNCHXL-F28069M: Can I use InstaSPIN-FOC with my on driver board?

https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/561565

For DRV8305 configuration, you have a look at the datasheet of DRV8305 as we replied to you before, change the related register to increase the Vds. The following codes for your reference.

// initialize the DRV8305 interface
HAL_setupDrvSpi(halHandle,&gDrvSpi8305Vars);

gDrvSpi8305Vars.Ctrl_Reg_05.IDRIVEP_HS = ISour_HS_1p000_A;
gDrvSpi8305Vars.Ctrl_Reg_05.IDRIVEN_HS = ISink_HS_1p000_A;
gDrvSpi8305Vars.Ctrl_Reg_06.IDRIVEP_LS = ISour_LS_1p000_A;
gDrvSpi8305Vars.Ctrl_Reg_06.IDRIVEN_LS = ISink_LS_1p000_A;
gDrvSpi8305Vars.Ctrl_Reg_07.DEAD_TIME = DeadTime_500_ns;

gDrvSpi8305Vars.Ctrl_Reg_0C.VDS_LEVEL = VDS_Level_1p892_V;

gDrvSpi8305Vars.Ctrl_Reg_0A.GAIN_CS1 = Gain1_10VpV;
gDrvSpi8305Vars.Ctrl_Reg_0A.GAIN_CS2 = Gain2_10VpV;
gDrvSpi8305Vars.Ctrl_Reg_0A.GAIN_CS3 = Gain3_10VpV;

gDrvSpi8305Vars.WriteCmd = 1;

// Write new reg values into DRV
HAL_writeDrvData(halHandle,&gDrvSpi8305Vars);

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BOOSTL-DRV8305EVM: Abnormal Torque Output at Current > 20A