MCT8316AEVM: Test the BLDC motor using the EVAL board

Hi Deepti,

Please install the GUI latest version 1.1.5. you can find the "Read All Register" option as shown in the below picture

...

You need enter the right I2C address before performing any read/write operation.

Thanks,

Dhinesh

Attaching the missed screen capture

Thanks,

Dhinesh

In MCU GUI link 1.14 version is showing. 1.1.5 is not available. Trying to operate the motor in analog mode using ext potentiometer. As mentioned in the user guide: Default parameters need to initialisased?

Hi Deepti,

Please install GUI version 1.1.4.

Yes, the default parameters can be adjusted for improved performance. Please refer to the MCT8316A tuning guide for the procedures to tune those parameters.

Thanks,

Dhinesh

I could able to configure with the latest version. With 20V supply, in analog mode motor is rotating with minimal speed. But in display as attached electrical speed not showing and motor in Idle state is displayed. I had taken pole pair: 7 with mechanical speed: 15000 rpm. The electrical speed obtained is 3000Hz. Abnormal Speed Lockout threshold given is 1250Hz. The maxon motor used: EC-i 608328.

Hi Deepti,

You need to have "Auto read motor status" feature enabled to get this status variable update. please confirm whether you have enabled in it.

Thanks,

Dhinesh

Hi Dinesh,

I am facing issue in the operation of motor. I had shared the screenshot of the motor  details and the result of the motor under run mode.  I had operated at 28V DC with pole pair: 4 and CBC current limit of 8A with CSA gain 0.15V/A. the tuning parameters provided were A1= 10Hz/sec, A2= 20Hz/sec. Closed loop accel 3V/sec. First cycle frequency 3 Hz. Align time 250msec. Initial max mechanical speed :1000 rpm. But the motor is providing some sound and not rotating.

Hi Deepti,

Thank you for providing the performance table and motor parameters.

While the motor parameters fall within acceptable ranges, the current requirement exceeds the 8A maximum capacity of the MCT8316A. For this load level, we should consider the MCT8329A or MCF8329HS devices.

Let's adjust the parameters to enable motor operation. I've implemented "default slow acceleration" and set CBC to 8A.

I have a question regarding startup under load conditions: if load is present and the align stage cannot move the rotor, we need to either increase ALIGN time and current, or utilize IPD if the motor has sufficient saliency.

Additionally, please reduce both open loop and closed loop acceleration rates to accommodate the load inertia.

Please test with the attached JSON configuration and include oscilloscope waveforms in your next response.

{
  "signature": "oneui-register-data",
  "data": [
    [
      {
        "idx": 0,
        "id": "isd_config",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "motor_startup1",
        "value": "0x01400000"
      },
      {
        "idx": 2,
        "id": "motor_startup2",
        "value": "0x00000000"
      },
      {
        "idx": 3,
        "id": "closed_loop1",
        "value": "0x00000000"
      },
      {
        "idx": 4,
        "id": "closed_loop2",
        "value": "0x00000060"
      },
      {
        "idx": 5,
        "id": "closed_loop3",
        "value": "0x00000000"
      },
      {
        "idx": 6,
        "id": "closed_loop4",
        "value": "0x00000000"
      },
      {
        "idx": 7,
        "id": "const_speed",
        "value": "0x00000000"
      },
      {
        "idx": 8,
        "id": "const_pwr",
        "value": "0x1F400000"
      },
      {
        "idx": 9,
        "id": "150_deg_two_ph_profile",
        "value": "0x00000000"
      },
      {
        "idx": 10,
        "id": "150_deg_three_ph_profile",
        "value": "0x00000000"
      },
      {
        "idx": 11,
        "id": "trap_config1",
        "value": "0x00000000"
      },
      {
        "idx": 12,
        "id": "trap_config2",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "fault_config1",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "fault_config2",
        "value": "0x07000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "gd_config1",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "gd_config2",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "pin_config1",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "pin_config2",
        "value": "0x00000000"
      },
      {
        "idx": 2,
        "id": "device_config",
        "value": "0x00000000"
      },
      {
        "idx": 3,
        "id": "peri_config",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "ana_trim3",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "ana_trim4",
        "value": "0x00000000"
      },
      {
        "idx": 2,
        "id": "ana_trim5",
        "value": "0x00000000"
      },
      {
        "idx": 3,
        "id": "ana_trim6",
        "value": "0x00000000"
      },
      {
        "idx": 4,
        "id": "ana_trim7",
        "value": "0x00000000"
      },
      {
        "idx": 5,
        "id": "ana_trim8",
        "value": "0x00000000"
      },
      {
        "idx": 6,
        "id": "ana_trim9",
        "value": "0x00000000"
      },
      {
        "idx": 7,
        "id": "ana_trim10",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "algo_reserved1",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "algo_reserved2",
        "value": "0x00000000"
      },
      {
        "idx": 2,
        "id": "algo_reserved3",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "gate_driver_fault_status",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "controller_fault_status",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "sys_status1",
        "value": "0x00000000"
      },
      {
        "idx": 1,
        "id": "sys_status2",
        "value": "0x00000000"
      },
      {
        "idx": 2,
        "id": "sys_status3",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "device_ctrl",
        "value": "0x00000000"
      }
    ],
    [
      {
        "idx": 0,
        "id": "algo_ctrl1",
        "value": "0x00000000"
      }
    ]
  ]
}

Thanks and Best regards

Venkatadri S

Hi Venkatadri,

Currently we are not loading the motor. The motor is under free rotate condition, but the cycle by cycle current limit when we keep less than 8 A. Fault is occurring at cycle by cycle current limit. 

Hi Deepti,

Could you specify what type of fault occurred? Is this an overcurrent protection fault?

Please reduce the CBC setting and test under no-load conditions. Without load, the motor may accelerate beyond normal speed limits in high-torque applications

Thanks and Best regards

Venkatadri S

Hi Venkatadri,

When the current limit is reduced below 8A, under controller fault section fault is shown: Lock Current Limit and Cycle by Cycle current limit followed by Loss of Sync and Motor Lock. 

Afternoon we will check with the JSON configuration provided. While loading this register, I hope no need to adjust the tuning parameters. 

One more query I am having: Once the hardware is connected as per the guidelines 

1. Read all registers: shows 39 registers read

2. We configured default registers.

3. Clicked Auto read motor status and fault status.

4. Selected analog mode of control and provided the pole pair details with initial max mechanical speed as 1000 rpm and chosen the calculated value for abnormal speed threshold

5. Provided CBC current limit: 8A, CSA gain: 0.15V/A and chosen calculated 1.2V

6. Using POT we varied to check the motor status, accordingly varied the tuning parameters.

After this should we save the register? 

Hi Venkatadri,

Can u share the board schematic of MCT8316A eval board

Hi Deepti,

You can download the design files from the EVM page MCT8316AEVM Evaluation board | TI.com

Thanks and Best regards

Venkatadri S