Senior Design ECE 4901

Electro-mechanics

Prof. Ali Bazzi

10/03/2016

bazzi@uconn.edu

110/3/2016

2

Introduction

10/3/2016

Energy transformation between electrical and

mechanical forms.

Electrical Mechanical: Motor or actuator

Mechanical Electrical: Generator

Electric car http://www.teslamotors.com

Water pump http://www.grainger.com

Electric propulsion system http://www.ship-technology.com

3

Introduction

10/3/2016

What about these?

Wind turbine cross section. Source: visual.merriam-webster.com

Flywheel Energy Storage. Source: archithings.com

Generator in a power plant.Source: hensel-industry.com

4

Energy Conversion

10/3/2016

It is common to have an intermediate couplingstage between electrical and mechanical energytransformations: Electromagnetics!

Among the electromechanical energy conversiondevices that can be used in senior designprojects:

ElectromechanicalRelays

Transformers

Single-phase motors

Three-phase motors/generators

Stepper motors

5

Relays

10/3/2016

Low power signal controls a higher powercontact:

Solid-state relays use semiconductors asswitches.

Image Source: http://2.bp.blogspot.com/-t6tbGLB7hN8/ULOb7z1R1jI/AAAAAAAAAYY/ZS86wSo6mLw/s400/relay.gif

6

Transformers

10/3/2016

Ideal transformers have N1 turns of wire

magnetically coupled through ferromagnetic

material with N2 turns of wire.

Image Sources: http://www.galco.com/images/moreinfo/transformer_design.jpghttp://image.made-in-china.com/2f0j00eByTQMIdrkqW/Single-Phase-Transformer.jpg

7

Transformers

10/3/2016

v1(t) v2(t)

i1(t) i2(t)

N1 N2

1 1

2 2

1 1

2 2

( )( )

( )( )

( )

( )

d tv t N

dt

d tv t N

dt

v t Na

v t N

+

v1(t)

-

+

v2(t)

-

i1(t) i2(t)

N1:N2

1 2

2 1

1i N

i N a (Current i2 flowing to the load R)

+

v1(t)

-

+

v2(t)

-

i1(t) i2(t)

N1:N2

R

8

Three-Phase Rotating Magnetic Field

10/3/2016

Three-phase balanced (magnitude, frequency, and 120

degrees of phase shift) currents flowing through

sinusoidally spaced three-phase windings produce a

rotating magnetic field.

Image Sources: http://www.basilnetworks.com/article/motors/images/motor2pole.gifhttp://electriciantraining.tpub.com/14177/img/14177_91_1.jpg

9

Three-Phase Rotating Machines

10/3/2016

Induction Machines: Metal rotor bars

Aluminum bars in steel enclosure

Synchronous Machines: fixed magnetic field

Permanent magnet (interior or surface mount)

Wound rotor

Image Sources: http://www.industrial-electronics.com/image/3-phase-induction-motor-detail.jpghttp://www.completepowerelectronics.com/wp-content/uploads/2013/02/BLDC_Two_pole_brushless-DC-motor-with_three-phase-stator-winding.jpghttp://newenergyandfuel.com/wp-content/uploads/2010/02/Induction-Permanent-Magnet-Motor-Comparison.jpg

10

Stepper Motors

10/3/2016

Motion control applications with fixed steps.

Several phases can be excited in several modes

Image Sources: http://www.savagehomeautomation.com/storage/post-images/jj-stepper/figure1-stepper-motor.png?__SQUARESPACE_CACHEVERSION=1356982584656http://www.robotgear.com.au/Cache/Files/ProductImageOriginals/676_The%20inside%20of%20a%20bipolar%20stepper%20motor.jpg

11

Electric Drives

10/3/2016

Speed, torque, and motion control require power

electronics to modify voltage and current signals.

Typical drives are shown in the next slides.

Control of power electronic switches is provided

by:

Microcontrollers (PIC, MSP430, Altec, etc.)

FPGAs (Xilinx, NI, etc.)

Digital Signal Processors (TMS from TI, etc.)

Analog control circuitry

12

Hex-Bridge

10/3/2016

Image Source: http://dev.emcelettronica.com/files/u4/nduction_Motor_with_Optocoupler_Gate_Drivers.jpg

13

Stepper Motor Drive

10/3/2016

14

Control Signal Isolation

(Opto-Couplers)

10/3/2016

Image Source: http://www.mcmanis.com/chuck/robotics/tutorial/h-bridge/images/bjt-schematic.gif

15

Gate Drive

10/3/2016

Required to limit the current into a switching device

(MOSFET or IGBT)

Provides voltage offset to turn-on a high-side switch

(what is a high side switch?)

Check dead-time circuits

Image Source: http://m.eet.com/media/1055164/IntersilMot2.jpg

16

Gate Drive

10/3/2016

Typical gate drive circuits:

+15V

+15V

+

Vdc

-

0.47uF

2.2uF

EPG10G

22ΩIRF830

IRF830

220uF

220uF

RLoad

+Vout-

9 VDD VB 6

10 HIN HO 7

11 SD VS 5

12 LIN VCC 3

13 VSS LO 1

COM 2

IRF2113

0.47uF

22Ω

GND

+

+

+

+

+

17

Gate Drive

10/3/2016

Typical gate drive circuits:

VCCCOMCTRT

SD

LO1

LO2

VB1HO1

HO2

VS1

VB2

VS2

NC

IRF2453DPbf

1uF

Electrolytic

0.47uF

Ceramic

0.22uF

Ceramic

0.22uF

Ceramic

1K?

IRF830 IRF830

IRF830

IRF830

IC1

GND

22?

22?

22?

22?

1

23

4

5

67 8

9

1011

1213

14

+

VDC

-

A

B

AC Load