• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 30 subscribers
  • Views 281 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

[FAQ] What are motor parameters, why are they needed, and how do I measure them?

[FAQ] MCF8315C: motor related parameters about Ke

Lucas Jiang
Prodigy 20 points

Tool/software:

I am manually testing the motor related parameters and found that the test result of ke differs greatly from the result of MEPT. Why is that? Repeated testing still shows the same result.

The test method is as follows.

Use hand to manually spin the motor freely. A sinusoidal voltage waveform should appear on the oscilloscope. Measure the peak amplitude voltage EPH in milli-volts and time period TE in seconds.

The image below shows the waveform measured by the oscilloscope. Ke=440/2 *250/1000/√3=32mv/HZ.

However, the test results of MPET are shown in the figure below.

Why is there such a large difference in ke between the two?

I am looking forward to your response.Thank you.

  • 0
    TI__Mastermind 23322 points

    Hi,

    Can you share MPET setting, as per the waveform calculation your answer is correct.

    Thanks and Best regards

    Venkatadri S

  • 0 in reply to Venkatadri Shantaram84961
    TI__Prodigy 20 points

    Hi Venkatadri,

    The image below shows the results of my MPET test.

    The results are basically the same as yesterday, Ke = 18 mv/Hz.

    I only checked three when I was using it, as shown in the figure below. Like the motor studio user guide.

    I am very much looking forward to your reply, thank you very much.

  • 0 in reply to Lucas Jiang
    TI__Mastermind 23322 points

    Hi Lucas,

    Can you share the JSON, I want to see open loop to closed loop hand off configuration as well.

    Open loop A1, A2 need to be adjusted.

    You can do one test, probe voltage line when MPET is running, at instant when motor is stopped, we can see voltage (voltage probe between OUTA and GND).

    If we can spin the motor to higher speed in open loop, we get better accuracy.

    Thanks and Best regards

    Venkatadri S

  • 0 in reply to Venkatadri Shantaram84961
    TI__Prodigy 20 points

    Hi Venkatadri,

    Thank you very much for your reply, here is the JSON file.

    OK, I have a preliminary understanding of the relevant operations, and I will arrange time for testing later.

    I am very much looking forward to your reply, thank you very much.

    Fullscreen 5102.MCF8315C_Appliance_10to20W_Ceiling_Pedestal Fan__Spd100to1000Hz.json Download 
    {
"signature":"oneui-register-data",
"data":[
[
{
"idx":0,
"id":"ISD_CONFIG",
"value":"0x6C230C24",
"addr":"0x00000080"
},
{
"idx":1,
"id":"REV_DRIVE_CONFIG",
"value":"0x98119064",
"addr":"0x00000082"
},
{
"idx":2,
"id":"MOTOR_STARTUP1",
"value":"0x4B660803",
"addr":"0x00000084"
},
{
"idx":3,
"id":"MOTOR_STARTUP2",
"value":"0xA905C004",
"addr":"0x00000086"
},
{
"idx":4,
"id":"CLOSED_LOOP1",
"value":"0x061981B1",
"addr":"0x00000088"
},
{
"idx":5,
"id":"CLOSED_LOOP2",
"value":"0x89E50000",
"addr":"0x0000008A"
},
{
"idx":6,
"id":"CLOSED_LOOP3",
"value":"0x00000000",
"addr":"0x0000008C"
},
{
"idx":7,
"id":"CLOSED_LOOP4",
"value":"0x641912C0",
"addr":"0x0000008E"
},
{
"idx":8,
"id":"REF_PROFILES1",
"value":"0x00000000",
"addr":"0x00000094"
},
{
"idx":9,
"id":"REF_PROFILES2",
"value":"0x00000000",
"addr":"0x00000096"
},
{
"idx":10,
"id":"REF_PROFILES3",
"value":"0x00000000",
"addr":"0x00000098"
},
{
"idx":11,
"id":"REF_PROFILES4",
"value":"0x00000000",
"addr":"0x0000009A"
},
{
"idx":12,
"id":"REF_PROFILES5",
"value":"0x00000000",
"addr":"0x0000009C"
},
{
"idx":13,
"id":"REF_PROFILES6",
"value":"0x00000000",
"addr":"0x0000009E"
}
],
[
{
"idx":0,
"id":"FAULT_CONFIG1",
"value":"0xB76A4327",
"addr":"0x00000090"
},
{
"idx":1,
"id":"FAULT_CONFIG2",
"value":"0xFF022088",
"addr":"0x00000092"
}
],
[
{
"idx":0,
"id":"INT_ALGO_1",
"value":"0x8431613D",
"addr":"0x000000A0"
},
{
"idx":1,
"id":"INT_ALGO_2",
"value":"0x00000067",
"addr":"0x000000A2"
}
],
[
{
"idx":0,
"id":"PIN_CONFIG",
"value":"0x08000000",
"addr":"0x000000A4"
},
{
"idx":1,
"id":"DEVICE_CONFIG1",
"value":"0x00101465",
"addr":"0x000000A6"
},
{
"idx":2,
"id":"DEVICE_CONFIG2",
"value":"0xC000F107",
"addr":"0x000000A8"
},
{
"idx":3,
"id":"PERI_CONFIG1",
"value":"0x81C03F00",
"addr":"0x000000AA"
},
{
"idx":4,
"id":"GD_CONFIG1",
"value":"0x0C000000",
"addr":"0x000000AC"
},
{
"idx":5,
"id":"GD_CONFIG2",
"value":"0x00020000",
"addr":"0x000000AE"
}
],
[
{
"idx":0,
"id":"GATE_DRIVER_FAULT_STATUS",
"value":"0x00000000",
"addr":"0x000000E0"
},
{
"idx":1,
"id":"CONTROLLER_FAULT_STATUS",
"value":"0x00000000",
"addr":"0x000000E2"
}
],
[
{
"idx":0,
"id":"ALGO_STATUS",
"value":"0x00000004",
"addr":"0x000000E4"
},
{
"idx":1,
"id":"MTR_PARAMS",
"value":"0x00000000",
"addr":"0x000000E6"
},
{
"idx":2,
"id":"ALGO_STATUS_MPET",
"value":"0x07000000",
"addr":"0x000000E8"
}
],
[
{
"idx":0,
"id":"ALGO_CTRL1",
"value":"0x00000000",
"addr":"0x000000EA"
}
],
[
{
"idx":0,
"id":"ALGO_DEBUG1",
"value":"0x80000000",
"addr":"0x000000EC"
},
{
"idx":1,
"id":"ALGO_DEBUG2",
"value":"0x0000001C",
"addr":"0x000000EE"
},
{
"idx":2,
"id":"CURRENT_PI",
"value":"0x0159019B",
"addr":"0x000000F0"
},
{
"idx":3,
"id":"SPEED_PI",
"value":"0x02410186",
"addr":"0x000000F2"
},
{
"idx":4,
"id":"DAC_1",
"value":"0x00000000",
"addr":"0x000000F4"
},
{
"idx":5,
"id":"DAC_2",
"value":"0x00000000",
"addr":"0x000000F6"
}
],
[
{
"idx":0,
"id":"ALGORITHM_STATE",
"value":"0x00000000",
"addr":"0x00000190"
},
{
"idx":1,
"id":"FG_SPEED_FDBK",
"value":"0x7FFFFFFF",
"addr":"0x00000196"
},
{
"idx":2,
"id":"BUS_CURRENT",
"value":"0x00000000",
"addr":"0x00000410"
},
{
"idx":3,
"id":"PHASE_CURRENT_A",
"value":"0x00000000",
"addr":"0x00000440"
},
{
"idx":4,
"id":"PHASE_CURRENT_B",
"value":"0x00000000",
"addr":"0x00000442"
},
{
"idx":5,
"id":"PHASE_CURRENT_C",
"value":"0x00000000",
"addr":"0x00000444"
},
{
"idx":6,
"id":"CSA_GAIN_FEEDBACK",
"value":"0x00010003",
"addr":"0x00000468"
},
{
"idx":7,
"id":"VOLTAGE_GAIN_FEEDBACK",
"value":"0x00000002",
"addr":"0x00000472"
},
{
"idx":8,
"id":"VM_VOLTAGE",
"value":"0x00000000",
"addr":"0x00000474"
},
{
"idx":9,
"id":"PHASE_VOLTAGE_VA",
"value":"0x000261AE",
"addr":"0x0000047A"
},
{
"idx":10,
"id":"PHASE_VOLTAGE_VB",
"value":"0x000261AE",
"addr":"0x0000047C"
},
{
"idx":11,
"id":"PHASE_VOLTAGE_VC",
"value":"0x00033F62",
"addr":"0x0000047E"
},
{
"idx":12,
"id":"SIN_COMMUTATION_ANGLE",
"value":"0x00000000",
"addr":"0x000004B6"
},
{
"idx":13,
"id":"COS_COMMUTATION_ANGLE",
"value":"0x00000000",
"addr":"0x000004B8"
},
{
"idx":14,
"id":"IALPHA",
"value":"0x00000000",
"addr":"0x000004D2"
},
{
"idx":15,
"id":"IBETA",
"value":"0x00000000",
"addr":"0x000004D4"
},
{
"idx":16,
"id":"VALPHA",
"value":"0x00000000",
"addr":"0x000004D6"
},
{
"idx":17,
"id":"VBETA",
"value":"0x00000000",
"addr":"0x000004D8"
},
{
"idx":18,
"id":"ID",
"value":"0x00000000",
"addr":"0x000004E2"
},
{
"idx":19,
"id":"IQ",
"value":"0x00000000",
"addr":"0x000004E4"
},
{
"idx":20,
"id":"VD",
"value":"0x00000000",
"addr":"0x000004E6"
},
{
"idx":21,
"id":"VQ",
"value":"0x00000000",
"addr":"0x000004E8"
},
{
"idx":22,
"id":"IQ_REF_ROTOR_ALIGN",
"value":"0x00000000",
"addr":"0x00000524"
},
{
"idx":23,
"id":"SPEED_REF_OPEN_LOOP",
"value":"0x00000000",
"addr":"0x0000053C"
},
{
"idx":24,
"id":"IQ_REF_OPEN_LOOP",
"value":"0x00000000",
"addr":"0x0000054C"
},
{
"idx":25,
"id":"SPEED_REF_CLOSED_LOOP",
"value":"0x00000000",
"addr":"0x000005D2"
},
{
"idx":26,
"id":"ID_REF_CLOSED_LOOP",
"value":"0x00000000",
"addr":"0x00000604"
},
{
"idx":27,
"id":"IQ_REF_CLOSED_LOOP",
"value":"0x00000000",
"addr":"0x00000606"
},
{
"idx":28,
"id":"ISD_STATE",
"value":"0x00000000",
"addr":"0x00000680"
},
{
"idx":29,
"id":"ISD_SPEED",
"value":"0x00000000",
"addr":"0x0000068A"
},
{
"idx":30,
"id":"IPD_STATE",
"value":"0x00000000",
"addr":"0x000006BE"
},
{
"idx":31,
"id":"IPD_ANGLE",
"value":"0x00000000",
"addr":"0x00000702"
},
{
"idx":32,
"id":"ED",
"value":"0x00000000",
"addr":"0x00000748"
},
{
"idx":33,
"id":"EQ",
"value":"0x00000000",
"addr":"0x0000074A"
},
{
"idx":34,
"id":"SPEED_FDBK",
"value":"0x00000000",
"addr":"0x00000758"
},
{
"idx":35,
"id":"THETA_EST",
"value":"0x00000000",
"addr":"0x0000075C"
}
]
]
}

  • 0 in reply to Lucas Jiang
    TI__Mastermind 23322 points

    Hi Lucas,

    I will respond to you by tomorrow.

    Thanks and Best regards

    Venkatadri S

  • 0 in reply to Venkatadri Shantaram84961
    TI__Mastermind 23322 points

    Hi Lucas,

    The BEMF is not sinusoidal, this can be adding to measurement error.

    Is this motor with concentrated winding suitable for trapezoidal?

    Thanks and Best regards

    Venkatadri S