Detection of Torque, Speed, and Current of a Brushless DC Motor by using Back-EMF Variation of Non-Energized Phase

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Detection of Torque, Speed, and Current of a
Brushless DC Motor by using Back-EMF Variation of
Non-Energized Phase

• 2005/03/26
• Jaehwan Yeom
• PREM, Hanyang University

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Contents

• 1. Motivation
• 2. Fundamental Method
• 3. Proposed Method
• - Torque vs. Current
• - Torque vs. Speed
• 4. Result
• 5. Conclusion
• 6. Future Work

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1. Motivation

• Motor? ?? ?? ? ???
• ?? ??? ???? ??? Motor Constant ?? ????.
• Motor Constant? ????? ?? ?? ? ???,
• ??? ??? Motor???? ?? ?? ? ??.
• ?? ?? ???? ?? Motor? ?? ??? ????? ???.
• ?? ???
• Torque Meter? ???, ?? ??, ???, ??, ??, ?? ?? ????
  ?? ????? ?? ??.
• ?? ??? ?? Flexible Coupling ??? ?? ?? ?? ??? ???
  ??? ??? ??? ? ??.
• Requirements
• ?? ?? ??? ?? ?? ?? ??? ??? Motor Constant? ??? ?
  ??? ??.
• Stand-alone System
• ?? ??? ???? ??? ??.

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2. Fundamental Method

• ????? ?? ???? T-w
• ??? ?? ?? ???

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• Torque Meter? ??? ?? ??
• Torque Meter? ?? ??? ??? ??? ???? ???,
• Motor Analyzer? ???? Torque-Speed? ????,
• Current Probe? ???? ??? ??? ? ??.

lt Experimental setup to measure the
torque-speed-current characteristics gt
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3. Proposed Method

• Torque vs. Current
• Back-EMF Constant??? ??? ? ??.

• Motor? ??? total flux? ?? Back-EMF

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• Back-EMF Characteristics
• ???? ????? Inductance? ?? ??? ???? ??
• ???? ????? Inductance? ?? ??? ???? ??
• ???? ??? ?? ?? ??

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• Back-EMF Variation on Non-Energized Phase

lt Terminal Voltage gt
lt Neutral Voltage gt
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• ??? Back-EMF ?? ??

• Terminal Voltage? Neutral Voltage ???

• ??? Back-EMF? ??? ?? ???? Commutation Time??? ???
  ????? ??.

• Back-EMF

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• Motor Constant

Winner 5.4K Nidec 7.2K
Pole / Slot 8 / 12 8 / 12
Phase Resistance 2.75 O 1.25 O
Number of Turn 62 49
Torque Constant mN-m / A 13.8321 10.376
Experimental Result mN-m / A 14.14485 10.660595
Error 2.26 2.74
Bearing Ball FDB
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• Torque vs. Speed
• Speed? ?? ?? ??? ?? ??? ???? ??? ? ??.
• Torque Meter ?? ??
• Load
• Duty Full
• ??? ??
• No Load
• PI Control (Non-Duty Full)
• ??? ??? ?? ??
• ?? Torque? ??? ???? ?? ??? ??? ??.

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• Current Interpolation
• ??? Duty Rate? Current

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• Torque Meter? ??? ???? ????

• Proportional Equation

• Proportional Constant

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• ??? ????
• ???? Motor? ?? ?? ??? ??? ??.
• Nidec P120 ? 2.5O, Winner? 5.5 O?? ??? 2.2
• ????? ??? ??? 1.9

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• Calculated Current

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• ?? ?? ??
• ???? ??, Duty Full? ?????? ???? ??? ?? ??? ??
• Nidec P120? ??? ?? 265 mA
• Winner? ??? ?? 67 mA
• Torque Meter? ?? Flexible Coupling?? Motor? ??
  Torque Meter? ?? ????? ?? 50 mA? ?? ??? ?? ???
  ??

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Result

• Torque vs. Current Characteristics Nidec P120

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• Torque vs. Current - Winner

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• Torque vs. Speed Nidec P120

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• Torque vs. Speed - Winner

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Conclusion

• ??? ???? ??? Motor Constant? ??? ? ??.
• ??? ?? ??? ??? ???? ?? ????.
• Problem
• Statistics
• ??? ??? ?? Motor? ?? ?? ??.
• Nidec P120? ??? ??? ???? ????, Winner 5.4k? ???
  Torque Meter? ??? ??? Motor? ????? ?? ??? ?? ???
  ???.
• Exact loss value
• ??? ?? ?? ??? ? ???, ??? Motor Constant?? ???,
  Motor? ??? ???? ?? ?? ??? ? ??? ???.

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Future Work

• A-Bmos? ??
• ??? ??? ?? ?? ??
• Gain Tuning
• ??? Motor Constant? ?? ?? ??? ??? ? ??? Auto
  Parameter Detecting ??

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System and User Interface of Brushless DC Motor
Operating System Ver. 2.0
PREM, Department of Mechanical Engineering Hanyang
University, Korea ? ? ? ? ? ?
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Motivation

• ??? ??? ???? ??? ?? (NRL 2?? 3? ?? ??)
• ??? ??? ?? ?? ??? ??? ?? ??? 0.2 ??? ?? ??
• DSP ?? ? ?? ??? On-board ??? ? User Interface
  ??? ??? ?? ??? ?? ?? ???? ?? ??? ? User
  Interface? Display?? ?? ??

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Objective Methodology

• Objective
• DSP ?? ? USB ?? ??? On-board ???
• Motor ???? ???
• Window ??? User Interface
• Methodology

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System Implementation

• DSP ? All operating for driving the motor.
• USB controller ? Communication with PC
• FPGA (Field-Programmable Gate Array) ?
  Communication between DSP and USB

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System Demonstration

• Output of Brushless DC Motor Operating System
  Ver. 2.0
• Speed profile
• DC-link current profile
• Terminal voltage A, B, C profile
• Torque constant