Notes: Basics of Electrical Engineering – Comprehensive Study Notes

Course Information

• BL10A0102 BASICS OF ELECTRICAL ENGINEERING, Time: First year, Period 1, 2 credits
• Responsible teachers: Mehar Ullah (D.Sc. Tech.), Lindh (D.Sc. Tech.); Teaching Assistant: Mirza Samiha
• Use Moodle chat for questions
• Study material and assignments: found on Moodle; Literature: on Moodle, in Google, in library
• Purpose: to learn the basics; Electrical Engineering is a wide and important field; students and teachers come from diverse backgrounds

Teaching Methods

• Lectures (active method) and self-study
• Mandatory tasks in Moodle (quizzes), e.g., multiple-choice questions
• Students may use lecture material and internet searches to find solutions
• Each lecture has one Quiz on Moodle; you must answer the quiz each week
• Each assignment can be answered only once
• Lectures are provided as PDFs; Moodle updates may occur as needed

Assessment and Grading

• Final grade is calculated from quizzes (Moodle) and eEXAM
• Grading scale: 0–5
• Shorthand rules:
  • If 50% of answers are correct, grade = 1
  • If ≥90% correct, final grade = 5
  • Rounding: if the decimal is .5 or more, round up (e.g., 49.5% → 50% and grade 1)
• Grade mapping:
  • 0–49% → 0
  • 50% → 1
  • 60% → 2
  • 70% → 3
  • 80% → 4
  • 90% → 5

Assignment Example (Moodlｅ)

• Joseph Henry (1797–1878) was an American engineer who discovered several inventions; which ones?
• Options (select one or more):
  • a. Microphone
  • b. Relay
  • c. Lead battery
  • d. Electric door bell
  • e. iPhone
  • f. Lithium battery
• Note: The slide presents this as a sample Moodle assignment question.

Schedule and Main Milestones (Date, Subject, Lecturer)

• 3.9: Main milestones of electricity; Basic components: generator — Lindh, Ullah
• 12.9: Electricity supply — Lindh
• 17.9: Consumption — Lindh
• 24.9: Electric drives, Power electronics — Lindh
• 1.10: Electricity market — Lindh, Ullah
• 8.10: Power Systems, Smart Grid concept; Energy storages — Ullah
• 15.10: IoT and Power-to-X technologies — Ullah

Examinations

• Exam in exam rooms: you may go to a test eEXAM if you wish
• Instructions for eEXAM: https://elut.lut.fi/en/completing-studies/examinations/exam-electronic-examination

Why an Engineer Needs to Know Electricity

• Fields listed: Electricity Engineering, Energy Engineering, Environmental Engineering, Information Tech. Engineering, Mechanical Engineering, Industrial business and management

Course Outcomes (Why this course matters)

After completing the course, students will be able to:

• identify turning points in electrical engineering
• list essential electric power generation methods
• determine the most important end-uses of electricity
• explain electricity price formation
• identify applications of electrical engineering and describe their operating principles
• solve problems related to simple DC and AC systems
• understand how transformers and generators work
• understand how other technologies (e.g., IoT, PtX) can facilitate electrical engineering

What is Electricity? (Overview)

• Electricity is around us; we use it daily; it comes from wall sockets
• It is associated with a sinusoidal waveform and 240 V in many contexts
• Common concerns include electric shock and safety

Basic Visual Concept: Conduction in a Copper Wire

• Electrons move easily through copper wire
• In a lamp filament, resistance is high; electrons move less easily
• Illustration notes: exaggerated for clarity; resistive wire shown

The Electricity System (Big Picture)

• Supply, Consumption, Transmission & Distribution, Power Electronics, Control, Market Place

History and Innovations in Electricity (Key Ideas)

• Electricity has always existed in nature (magnetic stones, electric fish, lightning)
• Motors, light bulbs, and batteries are inventions to harness electrical power
• Electricity evolves through understanding magnetism, circuits, and energy conversion

Groundbreaking Inventions in Electrical Engineering

• Overview slide indicating major breakthroughs and contributors

A Brief History of Electricity (Early Concepts)

• Amber’s static electricity and magnetism observed in ancient times
• Chinese magnets used for navigation in 20th century BC (early magnetism)
• Compass knowledge in Europe developed much later; systematic electricity/magnetism experiments began in late 16th century

Early Pioneers and Milestones (People and Inventions)

• Ewald Georg von Kleist (1700–1748): invented first electrical storage device, the Leyden jar (condenser)
• Static electricity studies in 17th–18th centuries
• Leyden jar used to store static electricity (1740s) and showcased by experiments with the jar
• Peter van Musschenbroek as a reference in historical context

Galvani and Volta (Late 18th Century)

• Luigi Galvani concluded animals have electricity via frog thigh experiments
• Alessandro Volta disputed animal electricity and built the first battery (e.g., silver, zinc, and saltwater between plates)

Electricity and Magnetism: The 1820 Relation

• Hans Christian Ørsted demonstrated the link between electricity and magnetism: current in a conductor produces a magnetic field (compass deflection)
• This showed that electricity produces magnetism and laid groundwork for electromagnetism

Ampère and the Electromagnetic Interaction

• André-Marie Ampère showed that two parallel conductors with direct current in the same direction attract; opposite directions repel
• Developed mathematical relationships combining electricity and magnetism
• Right-hand rule mnemonic: If the right hand's fingers curl around a conductor with the thumb in the direction of current, the fingers indicate the magnetic field direction

Coulomb’s Law

• Charles Coulomb described the electrostatic force between stationary charges
• Developed a sensitive torsion balance to measure electrostatic and magnetic forces
• The unit of electrical charge is the coulomb (C)
• Coulomb’s law conceptually F = k
  Q1 Q2 / r^2 (with k = 1/(4πϵ0))

Benjamin Franklin

• 1752: Demonstrated that lightning and amber sparks are the same phenomenon
• Lightning is a natural form of electricity
• Invented the lightning rod to protect people and buildings; introduced the idea that electrons and conventional current flow in opposite directions

Joseph Henry (1797–1878)

• Early major American electricity researcher after Franklin
• Made many electromagnetism-related inventions
• Discovered self-inductance before Faraday
• Practical engineer; used electromagnets for various applications; developed an electric doorbell and pendulum-like electric motor
• Coil inductance L [H] and related concepts
• Invented the relay, enabling long-distance signaling (telegraph) and influenced early transformer concepts

Timeline of Key Figures (1900s Context)

• Timeline featuring Albert Einstein, H. Hertz, J. Maxwell, Henry, Faraday, Gauss, Ørsted, Ampere, Volta, etc.

Henry’s Relay and Transformer (Inductance and Signaling)

• Henry’s relay could ring a bell from a mile away; long connections worked best with high-voltage and many turns in the coil
• Early transformer concepts emerged from his experiments; henry named unit for inductance (SI, 1893)

Lighting, Utilities, and Early Electrical Industry

• Humphry Davy introduced the working principle of the light bulb in 1802
• Thomas Edison (1879) invented a practical light bulb; the world’s first electric utility was established in NYC (Sept 4, 1882)
• Edison Electric Illuminating Company of New York helped bring electric light to Manhattan
• Lead-acid battery enabled first commercial electric vehicles in Paris and London (1880s)
• Internal combustion engines gained prominence in the 1920s, affecting early electric vehicle testing

Ohm’s Law and Motor Prototypes (Historical Development)

• Early motor prototypes developed around the 1740s and later by Faraday and Henry
• Hippolyte Pixii developed a DC generator (1832)
• Thomas Davenport built a battery-powered electric motor (1834)
• William Sturgeon built a motor able to drive machinery (DC motor)
• Frank Julian Sprague (1884) demonstrated a motor with constant speed
• Nikola Tesla (1888) patented the AC motor; Tesla’s broader AC system included generator, transmission, motor, and lighting
• Basic circuit relationship (U = RI, I = U/R) appears as part of Ohm’s law foundations

Definitions of Key Electrical Quantities

• Charge: fundamental property causing force in an electromagnetic field; can be negative (electrons) or positive (protons); unit: Coulomb (C); symbol: Q
• Current: rate of electron flow through a point in a circuit; unit: Ampere (A); symbol: I; equation: $I = \frac{Q}{t}$
• Voltage: potential energy difference per unit charge between two points; unit: Volt (V); symbol: V; relation: often expressed via Ohm’s law or energy equations
• Energy: total work done or energy consumed over time; unit: joule (J) or kilowatt-hour (kWh); symbol: E; equations: $E = Pt \, \text{or}\, E = VI t$
• Power: rate of electrical energy transfer; unit: Watt (W); symbol: P; equation: $P = VI$

Alternating Current vs Direct Current (AC/DC)

• AC systems rose in the 1880s due to simpler generation and efficient transformer-based transmission
• The early challenge was the lack of an efficient AC motor; Tesla advanced AC motors and a complete AC system
• HVDC systems are used today for long-distance transmission (efficiency over long links), offshore connections, and to avoid frequency variations
• LVDC and smart grid concepts are evolving parts of modern grids

Notable Modern Figures and Concepts

• Nikola Tesla: championed AC systems; developed two-phase AC motor and a complete AC system
• Edison: advocated DC; fought with Tesla/AC in early public discourse on transmission methods

Global and National Energy Contexts

• Main sources of electrical energy globally: Renewable sources (water, wind, solar, geothermal, biomass) and non-renewable sources (coal, natural gas, oil, nuclear)
• The largest hydropower plant examples: Three Gorges Dam (China) 22.5 GW

Hydropower and Energy Calculations (Fundamentals)

• Power calculation for hydropower: Pel = η · ρ_w · g ·

dot{V} · Δh

• Pel: electrical power output
• η: efficiency
• ρ_w: density of water (~1000 kg/m^3)
• g: acceleration due to gravity (≈ 9.81 m/s^2)
• 
  dot{V}: volumetric flow rate
• Δh: head (water height difference)
  • Energy output over time: Output energy Eout = Pel · FLH, where FLH = Full Load Hours
  • Potential energy of water: Epot = m g h Δh; alternative expressions: Epot = ρ_w

V̇ t g Δh

• Relationship examples: Epot = m g h Δh = ρw

V̇ t g Δh = Pel t + Q (where Q is waste heat) and Pel = η ρ_w

V̇ g Δh

• Efficiency relationship: Pel = η · ρ_w · g ·

V̇ · Δh

• Example units and note: ρ_w ≈ 1000 kg/m^3; g ≈ 9.81 m/s^2

Hydropower Calculations: Worked Example (Vuoksi vs Niagara)

• Vuoksi Imatrankoski plant nameplate capacity: 192 MW
• Niagara Adam Beck plant capacity: 1997 MW
• Basic energy/power relations used:
  • Pel = 111,834,000 W = 112 MW (from given data)
  • Output over full load hours: Outputel = Pel × FLH = 112 MW × 7125 h ≈ 797 GWh
  • Alternative calculation: Pel = 1,412,640,000 W = 1413 MW; Outputel = Pel × FLH = 1413 MW × 7500 h ≈ 10,594,800 MWh = 10,595 GWh
• A concrete calculation shown: Pel = 111,834,000 W derived from flow, density, head, and efficiency; Outputel = Pel × FLH = 112 MW × 7125 h ≈ 797 GWh
• Discussion: the nameplate capacities differ from calculated Pel due to factors like efficiency, actual flow variability, and seasonal differences
• Key formulas used:
  • Pel = η · ρ_w · g ·

V̇ · Δh

• E_pot = m g h Δh
• Eout = Pel · t (or Pel × t)

Why Flow and Capacity Matter in Hydropower Economics

• Flow is not always even; higher capacity can handle higher flow rates at different times
• Some rivers require minimum flow rates, potentially requiring higher capacity
• Higher capacity costs more; there must be an economic justification
• Market electricity prices vary by time of day and season; capacity helps maximize profit
• Hydropower also serves to balance grid frequency; higher capacity can influence balancing markets

Finland Electrification (Historical Context)

• Finland electrification timeline:
  • 1882: First electrification in Finland (Finlayson’s weaving hall, Tampere)
  • Two 110-volt DC dynamos supplied early electricity
  • Finlayson established Finland’s first power plant and helped set an example for electrification
  • Early European cities with electric light included Paris, Strasbourg, Milan, London

Nordic Electrification Progression

• 1929: Imatra hydropower plant—the largest in the Nordic countries at that time
• Imatra hydropower plant built around Vuoksi river; several plants listed with capacities, years, and owners
• Table (selected examples):
  • Imatra: 192 MW; annual energy ~1000 GWh; head 25 m; Vuoksi river; Imatra city; year of construction 1928; owner Imatra Voima/Fortum
  • Petäjäskoski: 182 MW; annual energy ~687 GWh; head 20.5 m; Kemijoki; Rovaniemi; 1957
  • Pirttikoski: 152 MW; annual energy ~581 GWh; head 26.0 m; Kemijoki; Rovaniemi; 1959
  • Pyhäkoski: 147 MW; annual energy ~555 GWh; head 32.3 m; Oulujoki; Muhos; 1951
  • Seitakorva: 144 MW; annual energy ~511 GWh; head 24.0–17.0 m; Kemijoki; Kemijärvi; 1963
  • Taivalkoski: 133 MW; annual energy ~536 GWh; head 20.0 m; Kemijoki; Keminmaa; 1976
  • Ossauskoski: 124 MW; annual energy ~501 GWh; head 15.5 m; Kemijoki; Tervola; 1966
  • Isohaara: 112.5 MW; annual energy ~310 GWh; head 12.0 m; Kemijoki; Keminmaa; 1949
  • Valajaskoski: 101 MW; annual energy ~365 GWh; head 11.5 m; Kemijoki; Rovaniemi; 1960
  • Other plants listed with similar data

Hydroelectric Capacity and Geography (European context)

• Map-style data shows Finland and neighboring regions; distances/heights illustrate hydropower distribution; emphasis on Finland’s role in Nordic energy

Global Hydroelectric and Energy Context

• Finland has over 220 hydroelectric plants contributing to about 3.1 GW total capacity
• The Three Gorges Dam in China is the largest hydro plant worldwide with about 22.5 GW capacity

Calculating Power: Key Formulas and Variables

• General hydro power formula:
  • Pel = η · ρ_w · g ·

V̇ · Δh

• Where:
  • η: efficiency
  • ρ_w: density of water (kg/m^3)
  • g: acceleration due to gravity (m/s^2)
  • 
    V̇: volumetric flow rate (m^3/s)
  • Δh: head (m)
  • Energy output over time:
• Eout = Pel · t
• E_pot = m g Δh
• Epot can be written also as ρw · V̇ · t · g · Δh
  • Relationship between energy and efficiency:
• Pel = η · ρ_w · g ·
  V̇ · Δh
• Epot = Pel · t + Q (where Q is waste heat), thus Pel = η · ρw · g ·
  V̇ · Δh

Electric System and Power Management Concepts

• The electricity system components: SUPPLY, CONSUMPTION, TRANSMISSION & DISTRIBUTION, POWER ELECTRONICS, CONTROL, MARKET PLACE
• Modern grid considerations include balancing frequency and market dynamics; capacity decisions are driven by profit optimization
• HVDC vs LVDC perspectives highlight different use cases in modern grids (interconnections, offshore, urban microgrids, etc.)

Global Development of Electronics and Communications (Timeline Highlights)

• 1842: First telegraph tests (Morse)
• 1866: First working trans-Atlantic cable (telegraph)
• 1875: Telephone (Bell)
• 1895: Wireless connection (G. Marconi)
• 1901: First trans-Atlantic radio signal (Marconi)
• 1906: Vacuum tube
• 1927: Television; followed by ongoing advances in electronics

Development of Electronics and Semiconductors

• Early electronics relied on cathode-ray tubes (CRTs) in the 20th century
• The transistor, invented in 1947, spurred semiconductor development
• Jack Kilby (Texas Instruments) built the first integrated circuit in September 1958
• Semiconductors enabled smaller, cheaper, and more reliable devices

Energy Sources and Global Context

• Main global energy sources are divided into Renewable (water, wind, solar, geothermal, biomass) and Non-renewable (fossil fuels, nuclear)

Electrification in Finland: A Case Study

• Finland’s early electrification began in 1882, with 110-volt DC dynamos and the Finlayson factory
• Finland’s first power plant and early electrification set the nation on the track toward modern electricity use
• By the late 1920s, significant hydropower development transformed the Nordic energy landscape

Contemporary Hydropower in Finland and the Nordic Region

• Finland’s hydro portfolio includes dozens of plants; total capacity around a few GW range, with significant regional contributions
• Imatra and other plants illustrate the integration of hydropower into the Nordic energy system

Practical Calculations: Example Numbers and Reasoning

• Key constants used in hydro calculations:
  • ρ_w ≈ 1000 kg/m^3
  • g ≈ 9.81 m/s^2
• Example calculation steps (as shown in the notes):
  • Compute Pel from flow, head, density, gravity, and efficiency
  • Convert Pel to energy over a period using Eout = Pel · t or E_out = Pel · FLH
  • Compare nameplate capacity with calculated Pel to discuss real-world factors such as efficiency, head variation, flow variability, and capacity planning

Final Reminders and Quiz

• Remember to answer the quizzes in Moodle
• Thank you and see you next week!

Key Equations Summary (LaTeX)

• Ohm’s Law: $V = I R$
• Current: $I = \frac{Q}{t}$
• Voltage-Current-Energy relationships: $E = P t \, ext{or}\, E = V I t$
• Power: $P = V I$
• Hydropower output: P{el} = b7 \, \rhow \, g \, \dot{V} \, \Delta h
• Potential energy: $E_{pot} = m g h \Delta h$
• Relating mass flow to volume flow: $E<em>{pot} = \rho</em>w \dot{V} t \, g \, \Delta h$
• Output energy: $E<em>{out} = P</em>{el} \, t$
• Full Load Hours: $E<em>{out} = P</em>{el} \cdot ext{FLH}$
• Efficiency relation: $P<em>{el} = \eta \rho</em>w \dot{V} g \Delta h$
• Inductance (Henry) relation noted in historical context: unit named after Henry; $L\,[\mathrm{H}]$
• Basic DC and AC concepts: $U = RI\, ,\, I = \frac{U}{R}$
• Magnetic field direction (Ampère’s rule): right-hand rule as described in the notes

Connections to Foundational Principles

• The content connects electromagnetism (Ørsted, Ampère, Coulomb) with practical energy systems (hydropower, HVAC, HVDC)
• It links fundamental units and laws (Coulomb’s law, Ohm’s law) to large-scale engineering decisions (grid design, energy markets, balancing, and reliability)
• The historical progression shows how scientific discoveries translate into ubiquitous technologies (motors, transformers, electronics, and modern smart grids)