Basics of Electrical Energy

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# Basics of Electrical Power

## Ozan Keysan

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

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

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# Current

### Current is the rate of charge flow: \\(i=\frac{dq}{dt}\\)

### 1 A equals to 1 Coulomb/seconds.

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# Voltage

Voltage is related to the strength of the electric field. It is analogous to pressure in a hydraulic circuit.

###! Voltage is always measured between two points, that is why it is also called potential difference.

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## Analogy to Hydraulic System
#### - Voltage --> Pressure
#### - Electric Current --> Water Current
#### - Tap Resistance --> Resistance

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## Mechanical Power & Energy:
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## Linear Motion: 
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\\(P = F v = F \dfrac{dx}{dt}\\) Watt
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## Rotational:
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\\(P=T \omega = T \dfrac{d\theta}{dt} \\) Watt
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## Linear Motion: \\(W = \int P dt = F x \\) Joule
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## Rotational: \\(W= \int P dt = T \theta \\) Joule

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# Electrical Power & Energy
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##\\(Power = Voltage \times Current \\)

# \\(P = V I \\)  Watt

## Energy: \\(W = \int P dt = \int V(t) I(t) dt \\) 
## Unit of energy is Joules ( or kWh)
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## How much does it cost to turn on the kettle for 1 hour?

Electricity bills([photo1](https://raw.githubusercontent.com/ozank/ee281/master/images/fatura1.jpg), [photo2](https://raw.githubusercontent.com/ozank/ee281/master/images/fatura2.jpg)) are calculated in terms of kWh.

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# Where is the energy coming from?
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Brasil [700 MW Synchronous Generator](https://www.itaipu.gov.br/en/energy/generating-units)

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# How it is transferred?
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# Electric System of Turkey
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## Capacity: 77 GW
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## Max. Consumption: 43 GW (~22 million kettles)
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## Per Capita Consumption: 3320 kWh/year

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# Sources of Energy (Turkey)

## Hydro: 26%
<img src="http://www.nukte.org/files/images/hidrolik/hidrolik.jpg" alt="Drawing" style="width: 500px;"/>

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# Sources of Energy (Turkey)

## Coal: 29%
<img src="http://vlscopenhagen.files.wordpress.com/2009/12/coal-plant1.jpg" alt="Drawing" style="width: 400px;"/>

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# Sources of Energy (Turkey)

## Natural Gas: 38%
<img src="http://image.dieselpowermag.com/f/news/1207dp_is_the_natural_gas_really_greener/41858160/1207dp_01%2Bis_the_natural_gas_really_greener%2Bshell_gtl_plant_in_qatar.jpg" alt="Drawing" style="width: 500px;"/>
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# Sources of Energy (Turkey)

## Wind: 4.5%

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<img src="https://raw.githubusercontent.com/ozank/ee361/master/images/turkiye_elektrik_iletim.png" alt="Drawing" style="width: 750px;"/>

[Detailed Map](http://www.geni.org/globalenergy/library/national_energy_grid/turkey/graphics/teias_map.gif)

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# The most important rule of grid
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# SUPPLY = DEMAND

# Energy Generated = Energy Used

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# How it is controlled?

### USA Grid Control Room

[Britain Grid Control](https://www.youtube.com/watch?v=slDAvewWfrA)
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# How it is controlled?

## Turkey Grid Control Room (Gölbaşı)

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# How does an electric machine work?

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# Fundamental Idea of all AC Machines
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# Three Phase AC

<img src="http://www.ece.umn.edu/users/riaz/animations/sinwaves0.gif" alt="Drawing" style="width: 750px;"/>
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# Three Phase AC: Rotating MMF

### Rotating MMF induce voltage on the conducting rotor: [Coca Cola Motor](https://youtu.be/cIf9iPskgJs)

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# Why do we need transformers?
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# [War of Currents](http://en.wikipedia.org/wiki/War_of_Currents)

<img src="http://img.memecdn.com/thunderstruck_o_2855333.jpg" alt="Drawing" style="width: 600px;"/>
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# Direct-Current Grid

## - Transformers don't work with DC
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## - The magnitude of voltage could not be changed (without power electronics).
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## - Low-voltage transmission is inefficient
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####For curious students:

- [Edison's Revenge: Will Direct Current Make a Comeback?](http://www.scientificamerican.com/article/edisons-revenge-will-direct-current-make-a-comeback-in-us/)
- [60 years of HVDC](https://library.e.abb.com/public/aff841e25d8986b5c1257d380045703f/140818%20ABB%20SR%2060%20years%20of%20HVDC_72dpi.pdf)
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# Alternating-Current Grid
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## - Transformers can be used to step-up voltage
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## - Thinner/Cheaper transmission cables
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## - Energy can be transferred to long distances
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## - More Efficient (Including the efficiency of the transformer)

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## You can access this presentation from: [keysan.me/ee361](http://keysan.me/presentations)