MCF8329RRYEVM: Discrepancy in Motor BEMF Constant (Ke) Measurement using MPET

Tool/software:

Hello,

I'm encountering a significant discrepancy between a motor's datasheet specifications and the value measured by the MPET tool. I'm hoping someone can provide some insight into what might be causing this issue.

Motor & Specifications:

• Motor: 4-Pole Motor

• Datasheet BEMF Constant (Ke): 1.06 Vrms/Krpm

• Calculated Ke: 31.8 mV/Hz
  
  

Problem: When I run the MPET tool, it outputs a BEMF constant of 2000 mV/Hz. The tool completes with the message "Motor Ke measurement complete," but this measured value is drastically different from the datasheet value.

I have attached the JSON configuration file for the tool settings.

What should I check to troubleshoot this issue?

Thank you in advance for your help.

•  Motor Infomation
  

  Item	Value	Unit
  Model Name	FL28BL26-15V-8006AF
  Rated Voltage	15	VDC
  Rated Current	0.51	A
  Peak Current	2.5	A
  Line-to-Line Resistance, @20℃	8.2	Ω
  Line-to-Line Inductance	2.3	mH
  Torque Constant, Kt	13.7	mN·m/A
  Back-EMF Constant, Ke	1.06	Vrms/Krpm
  	31.8	mV/Hz
  Rated Output Power	6	W
  Rated Speed	8000	RPM
  Poles	4	–
  Winding Type	Star (Y)	–

• JSON
  {
  "signature":"oneui-register-data",
  "data":[
  [
  {
  "idx":0,
  "id":"ISD_CONFIG",
  "value":"0x6462AC20",
  "addr":"0x00000080"
  },
  {
  "idx":1,
  "id":"REV_DRIVE_CONFIG",
  "value":"0xA8200000",
  "addr":"0x00000082"
  },
  {
  "idx":2,
  "id":"MOTOR_STARTUP1",
  "value":"0x4D6948D4",
  "addr":"0x00000084"
  },
  {
  "idx":3,
  "id":"MOTOR_STARTUP2",
  "value":"0xA92A6007",
  "addr":"0x00000086"
  },
  {
  "idx":4,
  "id":"CLOSED_LOOP1",
  "value":"0x285B92B8",
  "addr":"0x00000088"
  },
  {
  "idx":5,
  "id":"CLOSED_LOOP2",
  "value":"0x8BADE3C2",
  "addr":"0x0000008A"
  },
  {
  "idx":6,
  "id":"CLOSED_LOOP3",
  "value":"0x03000006",
  "addr":"0x0000008C"
  },
  {
  "idx":7,
  "id":"CLOSED_LOOP4",
  "value":"0x02D903E7",
  "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":"0x80000000",
  "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":"0xB7F240A7",
  "addr":"0x00000090"
  },
  {
  "idx":1,
  "id":"FAULT_CONFIG2",
  "value":"0x79004000",
  "addr":"0x00000092"
  }
  ],
  [
  {
  "idx":0,
  "id":"INT_ALGO_1",
  "value":"0xA433003D",
  "addr":"0x000000A0"
  },
  {
  "idx":1,
  "id":"INT_ALGO_2",
  "value":"0x000003E7",
  "addr":"0x000000A2"
  }
  ],
  [
  {
  "idx":0,
  "id":"PIN_CONFIG",
  "value":"0x02000008",
  "addr":"0x000000A4"
  },
  {
  "idx":1,
  "id":"DEVICE_CONFIG1",
  "value":"0x00101460",
  "addr":"0x000000A6"
  },
  {
  "idx":2,
  "id":"DEVICE_CONFIG2",
  "value":"0x0000000E",
  "addr":"0x000000A8"
  },
  {
  "idx":3,
  "id":"PERI_CONFIG1",
  "value":"0x8BAD7980",
  "addr":"0x000000AA"
  },
  {
  "idx":4,
  "id":"GD_CONFIG1",
  "value":"0x9C450103",
  "addr":"0x000000AC"
  },
  {
  "idx":5,
  "id":"GD_CONFIG2",
  "value":"0x000000CD",
  "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":"0x3CEE0004",
  "addr":"0x000000E4"
  },
  {
  "idx":1,
  "id":"MTR_PARAMS",
  "value":"0x00FF0000",
  "addr":"0x000000E6"
  },
  {
  "idx":2,
  "id":"ALGO_STATUS_MPET",
  "value":"0x20000000",
  "addr":"0x000000E8"
  }
  ],
  [
  {
  "idx":0,
  "id":"ALGO_CTRL1",
  "value":"0x20000000",
  "addr":"0x000000EA"
  }
  ],
  [
  {
  "idx":0,
  "id":"ALGO_DEBUG1",
  "value":"0xCB840000",
  "addr":"0x000000EC"
  },
  {
  "idx":1,
  "id":"ALGO_DEBUG2",
  "value":"0x00000000",
  "addr":"0x000000EE"
  },
  {
  "idx":2,
  "id":"CURRENT_PI",
  "value":"0x02FC012F",
  "addr":"0x000000F0"
  },
  {
  "idx":3,
  "id":"SPEED_PI",
  "value":"0x00000000",
  "addr":"0x000000F2"
  },
  {
  "idx":4,
  "id":"DAC_1",
  "value":"0x0003F40E",
  "addr":"0x000000F4"
  }
  ],
  [
  {
  "idx":0,
  "id":"ALGORITHM_STATE",
  "value":"0x00000000",
  "addr":"0x00000196"
  },
  {
  "idx":1,
  "id":"FG_SPEED_FDBK",
  "value":"0x7FFFFFFF",
  "addr":"0x0000019C"
  },
  {
  "idx":2,
  "id":"BUS_CURRENT",
  "value":"0x00000000",
  "addr":"0x0000040E"
  },
  {
  "idx":3,
  "id":"PHASE_CURRENT_A",
  "value":"0xFFF80000",
  "addr":"0x0000043C"
  },
  {
  "idx":4,
  "id":"PHASE_CURRENT_B",
  "value":"0x00000000",
  "addr":"0x0000043E"
  },
  {
  "idx":5,
  "id":"PHASE_CURRENT_C",
  "value":"0x00080000",
  "addr":"0x00000440"
  },
  {
  "idx":6,
  "id":"CSA_GAIN_FEEDBACK",
  "value":"0x00000000",
  "addr":"0x00000450"
  },
  {
  "idx":7,
  "id":"VOLTAGE_GAIN_FEEDBACK",
  "value":"0x00020002",
  "addr":"0x00000458"
  },
  {
  "idx":8,
  "id":"VM_VOLTAGE",
  "value":"0x01FE6000",
  "addr":"0x0000045C"
  },
  {
  "idx":9,
  "id":"PHASE_VOLTAGE_VA",
  "value":"0x02558EB9",
  "addr":"0x00000460"
  },
  {
  "idx":10,
  "id":"PHASE_VOLTAGE_VB",
  "value":"0x0255FD93",
  "addr":"0x00000462"
  },
  {
  "idx":11,
  "id":"PHASE_VOLTAGE_VC",
  "value":"0x0255FD93",
  "addr":"0x00000464"
  },
  {
  "idx":12,
  "id":"SIN_COMMUTATION_ANGLE",
  "value":"0xF8000000",
  "addr":"0x000004AA"
  },
  {
  "idx":13,
  "id":"COS_COMMUTATION_ANGLE",
  "value":"0x00000000",
  "addr":"0x000004AC"
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  {
  "idx":14,
  "id":"IALPHA",
  "value":"0xFFF80000",
  "addr":"0x000004CC"
  },
  {
  "idx":15,
  "id":"IBETA",
  "value":"0x00171811",
  "addr":"0x000004CE"
  },
  {
  "idx":16,
  "id":"VALPHA",
  "value":"0x01C09B29",
  "addr":"0x000004D0"
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  {
  "idx":17,
  "id":"VBETA",
  "value":"0xFFD9922E",
  "addr":"0x000004D2"
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  {
  "idx":18,
  "id":"ID",
  "value":"0xFFE8E7EF",
  "addr":"0x000004DC"
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  "idx":19,
  "id":"IQ",
  "value":"0xFFF80000",
  "addr":"0x000004DE"
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  {
  "idx":20,
  "id":"VD",
  "value":"0x00266DD2",
  "addr":"0x000004E0"
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  {
  "idx":21,
  "id":"VQ",
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  "addr":"0x000004E2"
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  {
  "idx":22,
  "id":"IQ_REF_ROTOR_ALIGN",
  "value":"0x00000000",
  "addr":"0x0000051A"
  },
  {
  "idx":23,
  "id":"SPEED_REF_OPEN_LOOP",
  "value":"0x00000000",
  "addr":"0x00000532"
  },
  {
  "idx":24,
  "id":"IQ_REF_OPEN_LOOP",
  "value":"0x0189355E",
  "addr":"0x00000542"
  },
  {
  "idx":25,
  "id":"SPEED_REF_CLOSED_LOOP",
  "value":"0x00000000",
  "addr":"0x000005D0"
  },
  {
  "idx":26,
  "id":"ID_REF_CLOSED_LOOP",
  "value":"0x00000000",
  "addr":"0x0000060A"
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  {
  "idx":27,
  "id":"IQ_REF_CLOSED_LOOP",
  "value":"0x00000000",
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  {
  "idx":28,
  "id":"ISD_STATE",
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  {
  "idx":29,
  "id":"ISD_SPEED",
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  {
  "idx":30,
  "id":"IPD_STATE",
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  {
  "idx":34,
  "id":"SPEED_FDBK",
  "value":"0x00000000",
  "addr":"0x0000076E"
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  {
  "idx":35,
  "id":"THETA_EST",
  "value":"0x00000000",
  "addr":"0x00000774"
  }
  ]
  ]
  }
  
  
• Motor Studio