WEEK 2A: ELECTRICAL LOAD Flashcards
- Any device which dissipates (consumes) power
- Defined by impedance (resistance, reactance)
- Modelled in aggregated way in the context of power systems
electrical load
The real component is the [?] which results to dissipation of heat
(usable energy).
resistance
The imaginary component is [?] which instead of dissipating
heat, energy is stored.
reactance
Types of Loads (RIC)
- resistive
- inductive
- capacitive
- Resists current linearly, producing heat and light
- E.g. incandescent bulbs, iron, toaster
- Power is real component only (Watts)
Resistive Loads
- Resists changes in current
- E.g. motors (fans, pumps), solenoids, relays
- Power has real (W) and reactive component (VAR)
Inductive Loads
- Resists changes in voltage
- Not very common; e.g. flashbulb, heart defibrillator
- Power has real and reactive (but negative) compone
Capactivie Loads
Types of Loads (AC or DC)
- AC
- DC
- Purely resistive (can be both ac and dc)
- can be interfaced to one type and vv
require specific frequency and voltage such as motors, and fluorescent lamps.
AC Loads
include those with battery system like most electronics
DC Loads
can be used both for AC and DC (example incandescent lights).
Purely Resistive Loads
- Simplest type of load
- tolerant to variations in power quality: Not affected by voltage or
frequency (or whether it alternates at all)
Resistive Load
resistive load power factor
1.0
- 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)
Lighting
A lighting system consists of the (5)
- light bulb
- power regulators (e.g. ballasts)
- converters (LED light bulbs)
- luminaires
- controls
The quantity of visible light is measured in
lumens (lm)
to connect lumens
with the electrical property, the [?] is usually given
luminous efficacy (lumens/Watt)
- 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
incandescent - tungsten wire
- 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
Fluorescent
- More expensive
- Long lamp life (dependent on electronics)
LED Lights
Types of Lighting
- incandescent
- fluorescent
- Compact fluorescent lamps (CFL)
- LED lights
- 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)
motors
Electronic Devices
- 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.
refers to a quantity of power not energy
demand
, is represented in a load
profile or a demand curve
instantaneous demand
tends to be the most
important factor to a system operator, is called the peak load, peak demand, or simply
peak
maximum demand
change shapes based on type of use, season, location, and weather
daily demand curve
- 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
need for storage
An electrical component that can be considered as a load (and a generator)
storage
reducing the peak demand from the grid
peak load shaving
Types of Storage
- chemical
- mechanical
- electrical
- Batteries: Lead-Acid, Li-ion based, redox batteries
- Fuel cells: hydrogen
Chemical Storage
- Pumped hydro (e.g. Caliraya lake)
- Flywheel
- Stored mass
- Compressed air
- Heat storage: molten salt, water, grave
Mechanical Storage
- Superconductive magnetic energy storage
- capacitors
Electrical Storage
Examples of Energy Storage in
Power Systems in the
Philippines
- Solar Power Philippines Paluan microgrid
- Kalayaan Pumped Hydro Storage
- AES Masinloc Energy Storage System
- 5 ha
- 2MW solar, 2 MWh
Tesla batteries with
a 2 MW diesel
generator
- Solar Power Philippines Paluan microgrid
- 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
- Kalayaan Pumped Hydro Storage
- 10MW battery for ancillary services
- AES Masinloc Energy Storage System
fast charging system for electric
vehicles developed at EEE Institute
Charging in Minutes (CharM)
