EE362-Electromechanical Energy Conversion-II

class: center, middle

# EE-362 ELECTROMECHANICAL ENERGY CONVERSION-II

## Ozan Keysan

[ozan.keysan.me](http://ozan.keysan.me)

Office: C-113 <span class="meta">•</span> Tel: 210 7586

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# Induction in a Coil
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## How many ways to induce voltage?
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- ## Time variation of flux (e.g. AC excitation)
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- ## Due to conductor movement in a stationary field
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- ## Rotation (\\(\vec{B}.dA\\) changes)

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# Example in an Electric Machine
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<img src="http://2.bp.blogspot.com/-vu0trwPmjfQ/Udui1xwkcuI/AAAAAAAAAK0/GM4q6DAQvIc/s320/salient_alternator.jpg" alt="Drawing" style="width: 500px;"/>

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# Directions
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## - Axial
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## - Radial
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## - Tangential
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![](http://www.materials.unsw.edu.au/sites/default/files/directions.png)

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# Electric Machine Parts
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## Rotor
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## Stator
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## Airgap
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## Tooth
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## Slot

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# Electric Machine Parts

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# Electric Machine Parts

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# Group Exercise
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## Warming-up Question

### A fisherman rowing his boat on a very small lake throws his anchor into the water.

### Does the water level of the lake rise, fall, or stay the same?

[Feynman Lectures](http://www.feynmanlectures.info/exercises/boat_anchor_lake.html)

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# Group Exercise:

## Design a magnetic coupling.
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### How many different magnetic coupling designs can you find?
### You have lots of permanent magnet, Iron and Copper, but no electric source.

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# WHY 3 PHASE? (but not 2 or 5?)
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# WHY 3-PHASE?

- # More power per unit wire length.

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- # Constant Power
[Power Graphs](https://docs.google.com/spreadsheets/d/1RP-MsrHwybAG6J3CFTbdLOCTvGdIdkaWUkhRuAHPWd0/edit?usp=sharing)

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- # Rotating MMF
(wait until EE362)

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# Rotating Magnetic Field !!
## The most important term for EE362

## What is it??
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### [Coca-Cola Motor](https://www.youtube.com/watch?v=cIf9iPskgJs)

### [Simplest AC Motor](https://www.youtube.com/watch?v=vbh_yR9Ngc0)

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# Single Phase AC: A time varying signal

# \\(I=sin(\omega t)\\)

### X-axis: Time
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# MMF created by a single coil

### If excited by DC:

## \\(MMF=F_m cos(\theta)\\)

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## MMF created by a single coil

## What happens if the coil is excited with AC?
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### DC excitation waveform multiplied with a time varying sinusoid: \\(sin(\omega t)\\)

## \\(MMF=F_m cos(\theta) sin(\omega t)\\)
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## Standing wave!

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<img src="https://sayingimages.com/wp-content/uploads/tesla-quotes.jpg" alt="Drawing" style="width: 750px;"/>

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# Three Phase AC

## Invented by Nicola Tesla in 1880s

### was independently invented by [Galileo Ferraris](https://en.wikipedia.org/wiki/Galileo_Ferraris), [Mikhail Dolivo-Dobrovolsky](https://en.wikipedia.org/wiki/Mikhail_Dolivo-Dobrovolsky), [Jonas Wenström](https://en.wikipedia.org/wiki/Jonas_Wenstr%C3%B6m) 
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# Three Phase AC

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# Three Phase AC: Rotating MMF

<img src="http://www.ece.umn.edu/users/riaz/animations/vecmovieslow.gif" alt="Drawing" style="width: 500px;"/>
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# Three Phase AC: Rotating MMF

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# Let's derive it:
## Yes it is boring, but quite important.
### [Simplest AC Motor](https://www.youtube.com/watch?v=vbh_yR9Ngc0)
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#### You have three coils, seperated with \\(2 \pi/3 \\) radians and excited with 3-phase current.

## \\(I\_A (t) = I\_m cos (\omega t )\\)
## \\(I\_B (t) = I\_m cos (\omega t - 2\pi /3 )\\)
## \\(I\_C (t) = I\_m cos (\omega t - 4\pi /3)\\)

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## \\(F\_A (t) = F\_m cos (\theta) cos (\omega t )\\)
## \\(F\_B (t) = F\_m cos (\theta - 2\pi/3) cos (\omega t )\\)
## \\(F\_C (t) = F\_m cos (\theta- 4\pi/3) cos (\omega t )\\)
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## \\(F\_{total} (t) = F\_A + F\_B + F\_C \\)
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## \\(F\_{total} (t) = \dfrac{3}{2}F\_m cos (\theta - \omega t) \\)
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# Rotation MMF

## \\(F\_{total} (t) = \dfrac{3}{2}F\_m cos (\theta - \omega t) \\)

### Generalized solution:
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## N-phase

## \\(F\_{total} (t) = \dfrac{N\_{phase}}{2}F\_m cos (\theta - \omega t) \\)

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# Fundamental Idea of all AC Machines
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<img src="http://familywings.org/wp-content/uploads/2012/01/donkey-and-carrot.jpg" alt="Drawing" style="width: 600px;"/>
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# Rotating MMF

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<img src="https://s-media-cache-ak0.pinimg.com/originals/92/86/54/9286549c76feba31890b5cce45690e0d.jpg" alt="Drawing" style="width: 600px;"/>

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<img src="http://www.tarihiolaylar.com/img/galeri/galeri_teslanin-cevabi-jpg_366628251_1440509349.jpg" alt="Drawing" style="width: 800px;"/>

### [Nikola Tesla vs Thomas Edison. Epic Rap Battles of History](https://www.youtube.com/watch?v=gJ1Mz7kGVf0)

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## You can download this presentation from: [keysan.me/ee362](http://keysan.me/ee362)