WEEK 2A: ELECTRICAL LOAD

Question 1

• Any device which dissipates (consumes) power
• Defined by impedance (resistance, reactance)
• Modelled in aggregated way in the context of power systems

Answer 1

electrical load

Question 2

The real component is the [?] which results to dissipation of heat
(usable energy).

Answer 2

resistance

Question 3

The imaginary component is [?] which instead of dissipating
heat, energy is stored.

Answer 3

reactance

Question 4

Types of Loads (RIC)

Answer 4

• resistive
• inductive
• capacitive

Question 5

• Resists current linearly, producing heat and light
• E.g. incandescent bulbs, iron, toaster
• Power is real component only (Watts)

Answer 5

Resistive Loads

Question 6

• Resists changes in current
• E.g. motors (fans, pumps), solenoids, relays
• Power has real (W) and reactive component (VAR)

Answer 6

Inductive Loads

Question 7

• Resists changes in voltage
• Not very common; e.g. flashbulb, heart defibrillator
• Power has real and reactive (but negative) compone

Answer 7

Capactivie Loads

Question 8

Types of Loads (AC or DC)

Answer 8

• AC
• DC
• Purely resistive (can be both ac and dc)
• can be interfaced to one type and vv

Question 9

require specific frequency and voltage such as motors, and fluorescent lamps.

Answer 9

AC Loads

Question 10

include those with battery system like most electronics

Answer 10

DC Loads

Question 11

can be used both for AC and DC (example incandescent lights).

Answer 11

Purely Resistive Loads

Question 12

• Simplest type of load
• tolerant to variations in power quality: Not affected by voltage or
  frequency (or whether it alternates at all)

Answer 12

Resistive Load

Question 13

resistive load power factor

Answer 13

1.0

Question 14

• One of the first applications of electricity
• Lamps, ballasts, starters, converters, luminaires and controls
• Lumens (lm): measure of total quantity of visible light
• Luminous efficacy (lumens / W)

Answer 14

Lighting

Question 15

A lighting system consists of the (5)

Answer 15

• light bulb
• power regulators (e.g. ballasts)
• converters (LED light bulbs)
• luminaires
• controls

Question 16

The quantity of visible light is measured in

Answer 16

lumens (lm)

Question 17

to connect lumens
with the electrical property, the [?] is usually given

Answer 17

luminous efficacy (lumens/Watt)

Question 18

• Inexpensive, easy to use, excellent color rendering, easy to dim, free of toxic components, instant switching, can also be used for heating
• Short lamp life, low luminous efficacy, heat generation

Answer 18

incandescent - tungsten wire

Question 19

• Low pressure gas discharge light source (with [?] powder and mercury vapor)
• Long tubular bulb with an electrode at each end
• Inexpensive, good luminous efficacy, long lamp life
• Needs auxilliary ballast and starter, contains mercury

Answer 19

Fluorescent

Question 20

• More expensive
• Long lamp life (dependent on electronics)

Answer 20

LED Lights

Question 21

Types of Lighting

Answer 21

• incandescent
• fluorescent
• Compact fluorescent lamps (CFL)
• LED lights

Question 22

• Significant fraction of residential, commercial and industrial load
• Fans, pumps (fridge, A/C), power tools, electric vehicles
• Electrical to mechanical energy conversion
• Mechanical power output is expressed in horsepower (hp) = 746W
• AC motors: induction, synchronous
• DC motors: high torque, used for locomotive applications
• Sensitive to power quality (excessive heating)

Answer 22

motors

Question 23

Electronic Devices

Answer 23

• Low voltage DC
• may be supplied by batteries or psu (e.g. ATX: 12V, 5V, 3.3V), chargers
• usually small power demand
• Less intense computing = less energy
• Phantom load: energy used in standby mode
• In combination with other types of load:
  computers with motors, lights, etc.

Question 24

refers to a quantity of power not energy

Answer 24

demand

Question 25

, is represented in a load profile or a demand curve

Answer 25

instantaneous demand

Question 26

tends to be the most important factor to a system operator, is called the peak load, peak demand, or simply peak

Answer 26

maximum demand

Question 27

change shapes based on type of use, season, location, and weather

Answer 27

daily demand curve

Question 28

* No need to generate when it will be used * Reliable power: guarantee sufficient supply of energy during time of peak demand or when resource unavailable (e.g. rural electrification) * Power quality improvement: intermittence of RE * Peak load shaving

Answer 28

need for storage

Question 29

An electrical component that can be considered as a load (and a generator)

Answer 29

storage

Question 30

reducing the peak demand from the grid

Answer 30

peak load shaving

Question 31

Types of Storage

Answer 31

- chemical - mechanical - electrical

Question 32

* Batteries: Lead-Acid, Li-ion based, redox batteries * Fuel cells: hydrogen

Answer 32

Chemical Storage

Question 33

* Pumped hydro (e.g. Caliraya lake) * Flywheel * Stored mass * Compressed air * Heat storage: molten salt, water, grave

Answer 33

Mechanical Storage

Question 34

* Superconductive magnetic energy storage * capacitors

Answer 34

Electrical Storage

Question 35

Examples of Energy Storage in Power Systems in the Philippines

Answer 35

- Solar Power Philippines Paluan microgrid - Kalayaan Pumped Hydro Storage - AES Masinloc Energy Storage System

Question 36

* 5 ha * 2MW solar, 2 MWh Tesla batteries with a 2 MW diesel generator

Answer 36

- Solar Power Philippines Paluan microgrid

Question 37

* Situated in Laguna, water is pumped from Laguna Lake to Lake Caliraya. To produce electricity, water is released from Caliraya Lake to run a turbine

Answer 37

- Kalayaan Pumped Hydro Storage

Question 38

* 10MW battery for ancillary services

Answer 38

- AES Masinloc Energy Storage System

Question 39

fast charging system for electric vehicles developed at EEE Institute

Answer 39

Charging in Minutes (CharM)