performance of power MOSFET Transistors at Cryogenic (LN2) Temperatures:

1
Application of Information Technology Tools in
Teaching the Course of Power Electronics Shuhui
Li

June 24, 2005 Presented at NSF CCLI Project
Evaluation (0311145) Texas AM University -
Kingsville
2
History

• In the absence of any control, electric motors
  operate at essentially a constant pump speed.
• Inefficient heat generated in pump and
  throttling system.
• Not amenable to automation.

3
Trend Adjustable Speed Drives (ASDs)

• Driven at an appropriate speed
• higher energy efficiency
• easier to automate
• lower maintance

4
Adjustable Speed Drives (ASDs)

• Role of electric drive efficient energy
  conversion from electrical to mechanical.
• Role of the PPU (power electronic converter)
  delivers appropriate from of energy to motor (as
  required by the load).

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Role of power electronics

• Electronic devices (power processing unit, power
  converter).
• Role
• Convert, process and control the flow of electric
  energy by supplying voltages and currents in a
  form that is optimally suited for user loads.
• Block diagram of a power electronic system

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Powering the Information Technology

• All modern computers rely on switch-mode power
  converters for their dc supply needs. 
• Only with power electronics is it feasible to
  build small power supplies with the many separate
  outputs and voltages needed for a computer, its
  peripherals, and its display.
• Power electronics is widespread in the
  telecommunications industry. 

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Hybrid Electric Vehicles
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Solar Energy
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Uninterruptible Power Supply (UPS)

• A device sitting between a power supply (e.g. a
  wall outlet) and a device (e.g. a computer) to
  prevent undesired features of the power source
  (outages, sags, surges, bad harmonics, etc.) from
  the supply from adversely affecting the
  performance of the device.

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Strategic Space and Defense Applications
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Harnessing Wind Energy
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Power Electronic Converter (PPU)

• Role of the PPU delivers appropriate form of
  energy to motor (as required by the load).
• Rectifier line frequency AC to DC.
• Switch-mode converter DC to energy form required
  by motor (DC/DC, DC/AC).

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Switch-mode Converters for DC and AC Motor Drives
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Full-Wave and Three-Phase Rectifiers

• Rectifiers are mainly used to produce an output
  that is purely DC.
• Line-frequency diode or thyristor rectifiers are
  used to convert 50- or 60-Hz ac input into a dc
  voltage in an uncontrolled or controlled manner.
• A large filter capacitor is connected across the
  rectifier for low ripple in the output dc voltage.

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Full-wave diode bridge rectifier with resistive
load

• Circuit diagram
• Output voltages
• dc voltage component
• DC and rms currents through the resistance

..\Power Electronics\Lec6\demo1.m
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SCR Controlled full-wave bridge rectifier with R
load

• Circuit diagram
• Output voltages
• dc voltage component
• DC currents through the resistance

c..\Power Electronics\Lec6\demo6.m
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Switch-Mode DC/DC Converters

• Applications
• Regulated switch-mode dc power supplies
• DC motor drives.
• DC-DC converter system

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Step-down Buck DC/DC converter
c..Power Electronics\Lec6\demo2_0.sch
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Step-up Boost DC/DC converter
c..\Power Electronics\Lec7\demo3_0.sch
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Four-Quadrant Converter for DC-Motor Drives
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Inverter Converting DC to AC - Bipolar
switching PWM

• Control requirement of the switches for
  sinusoidal PWM
• a sinusoidal reference signal (vsine)
• a triangular carrier signal (vtri).
• Load output voltage
• voVdc for vsinegt vtri
• vo-Vdc for vsinelt vtri
• Switch control
• vsinegt vtri S1 and S2 are on.
• Vsinelt vtri S3 and S4 are on.

c..\Power Electronics\Lec8\AC_biigb.sch
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PWM three-phase DC/AC inverter

• Each switch is controlled by comparing a
  sinusoidal reference wave with a triangular
  carrier wave.
• The fundamental frequency of the output is the
  same as the reference wave.
• The amplitude of the output is determined by the
  relative amplitudes of the reference and carrier
  waves.

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Three Phase Inverter AC-Motor Drives
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c..\Power Electronics\Lec9\buck_sw_fb_ctrl.sch
Feedback Control of Power Electronic Converters
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Publications

1. Shuhui Li and Rajab Challoo, Application of
   Information Technology Tools in Teaching the
   Course and Laboratory of Power Electronics, in
   the Proceedings of 2005 ASEE Annual Conference,
   Portland, Oregon, USA, June 12 15, 2005.
2. Shuhui Li, Using Computer Tools in Teaching of
   Power Electronics, in the Proceeding of the 2003
   NSF Summer Faculty Workshop on Teaching of First
   Courses on Power Electronics and Electric Drives,
   University of Minnesota, Minneapolis, Minnesota,
   July 10-13, 2003.

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Power Electronics and Drives Laboratory at TAMUK