ERRA Educational Workshop: Power System Basics for Non-EngineersDecember 9-11, 2019 | Vienna, Austria

Brief Introduction to Power SystemBarış Sanlı

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Brief Introduction

● Warming up● Q-A kind of way● Metaphors and Analogies● Some demonstrations

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General characteristics of electricity

● Very similar to light● Water analogy● Electrons are lazy● Not like any other markets● Real time operation (&costs)

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Q0 – What is different?

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Q1 – What has changed?● An electric car is charged● Traveled 350 km● Does its mass/weight change?● What has changed?

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Q2 – What is voltage?

● Dam● Height=Tension● Voltage difference

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Q3 – What is current?

● Current=movement of water molecules

https://theengineeringmindset.com/what-is-voltage/water-analogy-2/

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Q4 – What is resistance?

● Resists current(flow)● Crowded room(want to move side to side)

– More crowd-less person/second

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Q5 – Relation

● Voltage= Current*Resistance● Tension is relieved by the flow despite resistance

Voltage Current Resistance

Voltage(V)

Current(I) * Resistance(R)

Tension(V)

Flow(I) * Resistance(R)

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Q6 - Safety question

● Which one kills ? Tension or flow?● Voltage or Ampere?

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Q7-What is power?

● Is your car powerful?● Is it a sudden thing?● 0 to 100 km in … sec● In electricity Watt

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Q8 – What is energy?

● Ability to do work● Your car again

– How far it goes?● In electricity

– Power over time● Watt-hour

Energy

Power

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Q9-Conservation of Energy

● Energy given=Energy generated+losses

Energy=Muscle power100 unit

Energy=Electric power95 unit

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Q10 – What is active power?

● From bicycle– Ability to go forward

● In electricity – Tension*current– Voltage*Ampere– Watt

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Q11 – What is reactive power?

● Bicycle analogy● Another example

– Turn off TV– Red light goes off quickly– Energy is not given(!)

Reactive

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Q12 – Why USB cables are not long?

● Why USB cables are generally <1m?

5V 4.8V 4.4V 4V

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Q13 – What is AC and DC?

● AC: Alternating current– Grid electricity

● Generally mechanical origin ● Rotating bodies● (virtual inertia!)

● DC: Direct current– Solar, batteries (generally chemical/physical)– No rotation

https://en.wikipedia.org/wiki/Direct_current

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Q14 - Why AC?

● Easy to convert– Higher/lower voltages

● DC is like cell network– Hard to convert

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Q15 – Why high voltage?

● Power lost=current*current*resistor● Resistor=unique to cable● Change current to tweak loss● Transfer 1000MW for 1 hour

– 1 Volt * 1,000,000 Ampere– 100,000 Volt * 10 Ampere

● Typical Lightning~10,000-200,000 amperes

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Q16 – Why 220 Volts?

● A kettle -1800 Watts● 1800=220V*8.1Amps

● What if our house uses 5V?● 1800=5V*360 Amps● Lower distribution cost and loss!

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Q17 – What is frequency?

● Bicycle analogy

Pedalling rate

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Q18 – Why it is 50Hertz(EU)/60 Hertz(US)

● 50 cycles per second● To avoid costs/flickering● Higher freq higher losses

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Q19 – What is phase?

● Relative displacement● Single phase

– One wave● Three phase

– Three distinct – Same freq

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Q20 – Why three phases?

● 2 cables– 1 +, 1 – = 1P

● With additional 1 cable– If balanced– You can carry 3 P

https://erranet.org/

THANK YOU FOR YOUR ATTENTION!

Barış Sanlıbarissanli.com

barissanli.com