Md' Kaisar Rashid Khan

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Md. Kaisar Rashid Khan

• Ph. D (EE) Candidate
• University of Central Florida

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Believe in

• Professionalism
• Innovation
• Integrity
• Honesty
• Patience

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EDUCATION

• Ph. D, (EE) Expected date of Graduation Fall
  2007, University of Central Florida
• MSEE, The University of Texas at El Paso
• M. Eng, Bangladesh University of Engineering and
  Technology, Dhaka.
• B. Sc. Eng., Bangladesh Institute of Technology,
  Rajshahi

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Related Publication

• Kaisar R Khan, Q. Ahsan and M. R Bhuiyan,
  Expected Energy Production Cost of Two Area
  interconnected Systems with Jointly Owned Units
  Electric Power System Research journal
  (Elseiver), April 2004.
• Kaisar R Khan, Q. Ahsan and M. R Bhuiyan,
  Expected Energy Generation of Two Geographically
  Isolated Area System with Jointly Owned Units,
  Presented third International Conference on
  Renewable Energy for Sustainable Development,
  October 2003,Dhaka, Bangladesh

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Related Graduate Courses

• DSP
• Power Electronics
• Machine Design
• Power System Planning
• Power System Transient
• Power System Stability
• VLSI
• Advance Semiconductor Devices

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Research Focus Power Electronics and
electromagnetic modeling

• Major Advisor
• Dr. Thomas Wu
• Dept. of ECE, UCF

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Magnetic Circuit Analysis of PMSM using FEM
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Geometric Model
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Flux line distribution of the proposed motor at
(a)150A (b) 650A
(b)
(a)
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Flux Density Profile of the Proposed Motor
(a)150A
(b) 650A
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Torque Profile
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Supper High Speed PMSM

• Kaisar Khan, Dr. Liping Zheng, Dr. Thomas Wu and
  Dr. L. Chow
• University of Central Florida

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Rotor and its components
Winding using multi-strand Litz-wire
The specifications of the axial flux PMSM
Axial view of the axial flux PMSM
Winding with a total of 84 turns
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Winding Modeling
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Flux Back EMF
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Torque Simulation

• Constant torque is required. Torque ripple should
  be as small as possible.
• Virtual Work
• Field oriented current applied.
• Torque constant 0.004 N.m /A

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Housing and Cooling
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Dynamic Torque and Back EMF
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Some Parameters

• Phase resistance 0.06 ?
• Phase inductance 1.6 ?H _at_ f1 KHz
• 2.0 ?H _at_
  f100 Hz
• Rotor inertia 3.652?10-5 Kgm2
  .
• Back EMF constant 0.138 V/Krpm
• Maximum speed 100,000 rpm
• Nominal speed 50,000 rpm

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Load Test Method

• Measuring input phase to phase voltage (Vbc), and
  phase current (Ia).
• Tested efficiency
• 60 _at_ 50,000 rpm with 100 W output.

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Material Considerations

• Permanent magnet
• Nd-Fe-B (neodymium -iron-boron ) the highest
  energy density, does well above 135 K. However,
  it undergoes a spin reorientation below 135 K.
• Sm-Co (samarium cobalt) does quite well at both
  cryogenic temperature and higher temperature.
• Winding
• Multi-strand Litz-wire to reduce eddy current
  loss.
• Heavy insulation to withstand at 77 K.
• Stator
• Laminated low loss silicon steel 0.005
  thickness.

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PMSM Loss Sources

• Stator core loss
• Eddy current, hysteresis and excess loss
• Rotor loss
• Eddy current loss
• Copper loss
• I2R loss
• Eddy current loss due to skin effect and
  proximity effect
• Mechanical loss
• Bearing loss and windage loss

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Electrical Resistivity of Cu
? 1/10
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Copper Loss - Eddy Current

• Eddy current loss per unit conductor volume is

round wire
rectangular section conductor
where Bp is the peak flux density, ? is the
electrical angular frequency, d is the diameter,
and ? is the resistivity.
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Eddy Current Solid Wire
I 582 A
Solid Copper _at_ 77 K, diameter1.5 mm
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Eddy Current Litz-wire
I 37 A
75 strands _at_ AWG 36 (0.125 mm)
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Load Test Results (II)
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Motor Controller
Kaisar Khan, Limei Zhao, Thomas Wu and L.
Chow University of Central Florida
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Motor Drive
Simplified motor test circuitry
Current and voltage waveforms _at_ 60,000 rpm
space vector PWM drive and low pass filter
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The Controller Configuration
Hardware
TMS320LF2407A
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Controller Schematic
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Prototype under testing
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(No Transcript)
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MOSFET
MOSFET equivalent circuit in high frequency

• Cgd Gate-to-drain capacitance
• (Miller capacitance )
• Non-linear
• Affected by voltage
• Gate charge Q the lower, the better

• For low-power, high-frequency applications
• Up to a few kilowatts
• Heatsink
• 2 to 5 times larger than expected
• Power ratings
• Should be derated by 30 50 to ensure long-term
  reliability

Safe Operating Area (SOA)

• Fairchild FDP047AN08A0
• 75 V,80 A,4.7 mO, and 92 nC
• 2-4 MOSFET paralleling prototype

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Drive Chip IR2110
I_drive up to 2A sink and 2A source
Bootstrap circuit
t_rr lt 100ns
QgGate charge of high side FET, VLS Voltage
drop across the low side FET or load ffrequency
of operation , Vf Forward voltage drop across
the bootstrap diode twpulse width of level
shift currents , Icbs(leak)Bootstrap capacitor
leakage current Ilson/Ilsofflevel shift
currents required to switch on or off
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High Current Design (I)

• Electronic components are more sensitive to
  temperature extremes.
• Semiconductor long-term reliability is directly
  affected by operating temperatures.
• The maximum junction temperature is the critical
  design point for motor control power stages.
• Reliability research suggests that for each 10C
  rise in junction temperature, the long-term
  reliability is decreased by about 50 percent.
• Thermally effective packages have a much lower
  junction-to-case thermal resistance.
• 3,4 or 5 oz. copper conductors and planes help
  spread heat throughout the PCB making the module
  temperature more homogeneous and reducing hot
  spots.

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Loss Calculation

• Inverter takes almost all loss in controller
• MOSFET loss is main concern

95 in theory
94 of total switching loss
Up side
0.3 of total switching loss
3.7 of total switching loss
Low side Only 15 of low side total loss
Iout65 A, RDS(ON)2.35 mO, V11.4 V,Crss480 pF,
Fsw50 KHz, Igate1 A
MOSFET conduction loss is main loss for lt 1
MHz
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Prototype of HW of Controller

• Different controllers for different power rating
  motor systems
• Same concept block
• Different hardware topology,components,
  schematics, and layout
• Different software parameters, optimized code
• Two print circuit boards (PCB)
• The controller board low voltage components and
  trace
• The power stage board the high-voltage
  components and trace
• The power stage prototype need not change too
  much, but the controller board may change
  significantly. Making them into two different
  boards can make the optimization much easier.

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TI TMS320LF2407A
TI TMS320LF2407A Evaluation Board

• 16-bit fixed-point DSP
• Specifically designed for the Digital Motor
  Control

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Software Configuration
Optimal V/f control scheme helps to set boost
voltage, V/f slope, FL, FH
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Significant Results

• Efficiency as high as 90.
• No load maximum speed 120K (RPM)
• Achieve maximum speed of 60K with load.
• An axial flux pancake PMSM is presented for the
  first time. (Dr. Lipings sole contribution)

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Power System Planning
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Expected Energy Production Cost of Two Area
Interconnected Systems with Jointly Owned Units
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A new probabilistic methodology has been
developed to evaluate the expected energy
production cost of two area-interconnected
systems with a jointly owned unit as well as a
conventional unit.
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Expected Energy Generation and Inter Operator
Export-Import
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Effect of Tie-line Capacity Increase
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Significant Results

• The proposed method keeps track of the
  export/import of energy by the individual unit.
• The inclusion of a JOU in the system reduces the
  global capacity transaction at a higher tie line
  capacity however, the higher capacity
  transaction is observed at lower tie line
  capacities.

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An Important Case Study Implementing the
Developed Probabilistic Model

• Power System of Bangladesh

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Global Expected Energy Generation
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Effect of Tie-line Capacity Change
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PROFESSIONAL TRAINING

• GTA Certification course, Faculty resources
  center, UCF, Spring, 2005
• Laboratory safety orientation course, UT El Paso,
  2000
• Management training for the government officers
  in Bangladesh, Aug. Dec. 1998
• Substation design and maintenance training in
  BPDB, Rajshahi Dec, 1994
• Industrial attachment on video system to Philips
  Bangladesh Ltd., Dec 93 to Jan 94

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PROJECT PROPOSAL

• 189K Digital telephone installation project in
  Bangladesh, Submitted to the government of
  Bangladesh.
• Dynamic Magneto Transport Effect on Semiconductor
  Material, Kaisar Khan and Thomas Wu, submitted to
  SATOP.
• Remote RF Measurements for Pipeline Monitoring,
  (FloWatch Phase II), Jie Chen, Kaisar Khan and
  Thomas Wu, submitted to Emtel, Melbourne,
  Florida.
• RF sensor design for remote gas pipeline
  monitoring system, Kaisar Khan, Yupeng Chen and
  Thomas Wu, submitted to Emtel, Melbourne,
  Florida.

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TEACHING EXPERIENCE

• Teach under graduate courses and Labs in the area
  of electric machine, electronic, microprocessor,
  and networking as GTA / Adjunct Lecturer/Lecturer

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Priority

• GOD
• Family
• Work and Education
• Social Activity