Power Electronics for PV Systems

class: center, middle

# Power Electronics for PV Systems

## Ozan Keysan

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

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

---

# Electric System of Turkey
--

## Capacity: 77 GW
--

## Max. Consumption: 43 GW (~22 million kettles)
--

## Per Capita Consumption: 3321 kWh/year

<a href="http://databank.worldbank.org/data/embed/Elektrik-Tuketim/id/608e39e5?ti=y&ds=n&dd=n&tb=y&sh=n&dw=n&pr=n&inf=n&zm=y&md=y&navigator=n&theme=darkGrey&bdrClr=rgb(68,68,68)&bdrStyle=solid&bdrWidth=1px&title=Arial;14px;true;false;rgb(68,68,68);justify&exptypes=Excel,CSV,TabbedTxt">Comparison of a few countries, and their stories</a>

---
# Difference between Power and Energy?
--

## The unit of Energy is Joules (= Watt.Seconds).

## $$w=\int P(t) dt = \int V(t) I(t) dt$$

## Common unit for electrical energy: 
## kilo-watt hours (**kWh**).
---

# Cost of Energy
--

## How much does it cost to run a kettle for 1 min?
--

### Example: Electricity bills([photo1](https://raw.githubusercontent.com/ozank/ee281/master/images/fatura1.jpg), [photo2](https://raw.githubusercontent.com/ozank/ee281/master/images/fatura2.jpg))
---
# Electricity vs Human Force

## Energy used in a kettle for 1 min = How many kilograms of weight?
---

# Electricity vs Human Force

A healthy human can produce about 1.2 hp briefly and sustain about 0.1 hp (74.5W) indefinitely; trained athletes can sustain 0.35 hp (260 W). The Jamaican sprinter Usain Bolt produced a maximum of 3.5 hp (2.6 kW) 0.89 seconds into his 9.58 second 100-meter dash world record in 2009.

---
# Sources of Energy (Turkey)

## [Real Time Production](https://seffaflik.epias.com.tr/transparency/uretim/gerceklesen-uretim/gercek-zamanli-uretim.xhtml)

## [Whole-Sale Energy Price](https://seffaflik.epias.com.tr/transparency/piyasalar/gop/ptf.xhtml)
---
# How to Transmit Electricity?

Reading: [How New York City Gets Its Electricity](https://www.nytimes.com/interactive/2017/02/10/nyregion/how-new-york-city-gets-its-electricity-power-grid.html)

---
# How to Transmit Electricity?

## Simple Electric System

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

---
# Power Transformers

#### A three-phase 225 MVA, 275 kV power transformer, 241 tonnes

#### (Courtesy of Scottish Hydro)

---
# Why do we need transformers?
--

---
<img src="http://img.memecdn.com/thunderstruck_o_2855333.jpg" alt="Drawing" style="width: 700px;"/>
--

## [War of Currents](http://en.wikipedia.org/wiki/War_of_Currents)
## [AC/DC Music Band](https://youtu.be/gEPmA3USJdI?t=2m15s)

---

---
# Direct-Current Grid

## - Transformers don't work with DC
--

## - The magnitude of voltage could not be changed (without power electronics).
--

## - Low-voltage transmission is inefficient
--

####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)
---

# Alternating-Current Grid
--

## - Transformers can be used to step-up voltage
--

## - Thinner/Cheaper transmission cables
--

## - Energy can be transferred to long distances
--

## - More Efficient (Including the efficiency of the transformer)
---
# PV Systems

## Characteristics of a PV Panel
--

<img src="https://www.powersystemsdesign.com/images/articles/1384947035figure3.jpg" alt="Drawing" style="width: 800px;"/>
---
# MPPT
--

## Maximum Power Point Tracker
--

<img src="https://www.intechopen.com/source/html/47786/media/image2_w.jpg" alt="Drawing" style="width: 700px;"/>
---

# DC/AC Conversion

---

# DC/AC Conversion

<img src="https://media.digikey.com/photos/rdl/STEVAL_ISV003V1_Block_Diagram_Schematic_Full.jpg" alt="Drawing" style="width: 800px;"/>
---

## We use transistors,
--
which are rather big

## IGBT, MOSFET etc.
---

## Varios Topologies wrt Power Rating

---

---
# Effects on the Electric Grid

[Burdur PV Power Plant](https://www.google.com/maps/place/ANTEK+ENERJ%C4%B0/@37.3932263,30.4053761,3678m/data=!3m1!1e3!4m5!3m4!1s0x14c416ef73e8056f:0x42d2f0f08f77f046!8m2!3d37.3931562!4d30.402319?hl=en)

---
# The most important rule of grid
--

# SUPPLY = DEMAND
--

# Energy Generated = Energy Used

---
# How it is controlled?

### USA Grid Control Room

[Britain Grid Control](https://www.youtube.com/watch?v=slDAvewWfrA)
---

# How it is controlled?

## Turkey Grid Control Room (Gölbaşı)

## [Real Time Production](https://seffaflik.epias.com.tr/transparency/uretim/gerceklesen-uretim/gercek-zamanli-uretim.xhtml)

---
## What happens as the PV ratio increases?
--

---
# Duck Curve
--

<img src="http://1m5rjm4bgenp2600za110opv.wpengine.netdna-cdn.com/wp-content/uploads/2014/10/duck_curve_duck-771x536.png" alt="Drawing" style="width: 750px;"/>
---

# Negative Energy Prices
--

---
# Grid Level Storage
--

### [Tesla's Giant Australian Battery](https://www.gizmodo.com.au/2017/07/all-the-details-on-teslas-giant-australian-batteryt/)

---
# Grid Level Storage

---
# Grid Level Storage

<img src="https://www.cleanenergyfinanceforum.com/sites/default/files/Why1%2B1%3D3.jpg" alt="Drawing" style="width: 750px;"/>
---

# Electric Grid of the Present
<img src="https://static01.nyt.com/images/2017/01/08/nyregion/ny101-power-slide-OBHH/ny101-power-slide-OBHH-jumbo-v3.gif" alt="Drawing" style="width: 550px;"/>

---

# Electric Grid of Future
<img src="https://static01.nyt.com/images/2017/01/08/nyregion/ny101-power-slide-K259/ny101-power-slide-K259-jumbo-v3.gif" alt="Drawing" style="width: 550px;"/>
---
# Thanks
--

## keysan@metu.edu.tr

## [PowerLab: http://power.eee.metu.edu.tr](http://power.eee.metu.edu.tr)

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