Download Major Power Grid Components

Power Systems
Last edited: Monday, June 1st, 2015
Before Power Distribution
• Technology developed 50-100 years before power
distribution to the public:
• Batteries
• Arc Lights
• Incandescent Lights
• Electric Motors (vacuum pump)
DC vs. AC
• Direct current (DC)
– DC machines
– Batteries
– Fuel cells
– Photovoltaic
• Alternating current (AC)
– AC machines
– Power electronic converters
– 60 Hertz in the US
Brush Electric Company
• HVDC distribution that
transmitted over longer
distances to one customer
• Niagara Falls to Buffalo
• Simple distribution system
that could only power arc
lights
Edison Electric Company
• Low voltage direct current system
• Better lightbulb
• Safer
• Short range use
• Powered Small DC motors
• Features added
• Electric meter
• Distribution System
Westinghouse Electric Company
• Low and High Voltage Alternating Current system
• Long distance transmission
• Able to change voltage
• Compatible with Edison Bulb
• Developed Westinghouse Bulb
• Own patent for AC Motor
Grid Expansion
• Grid distribution networks expanded until around 1915.
• The smaller grids slowly integrated into one system by
connecting the distribution grids by transmission lines.
• More transmission lines were added during the 1930s as part
of the Depression projects and rural areas received
electricity
• By the 1960’s the gird was largely intact and upgrades
occurred to make the lines more reliable.
Major Power Grid Components
• Generation
• Transmission
– 115 kVolts 765 kVolts
– Networked
• Distribution
– 4 kVolts to 69 kVolts
– Radial
• Load
Major Power Grid Components
 All power systems have three major components:
Generation, Transmission/Distribution, and Load.
 Generation: Creates electric power.
Transmission/Distribution: Transmits electric power from
generation to load.
Load: Consumes electric power.
Power in = Power Out
The Electric Grid Model
Interconnections
AC Transmission Grid
DC Transmission Components
Transmission & Distribution
Transmission
Distribution
networked connections
radial connections
power can be supplied from
power moves in one direction
multiple sources
only
typically higher voltages, above typically lower voltages, below
100 kV
100 kV
mostly overhead, with some
most new construction is
underground, especially in
underground in urban areas
suburban and urban locations
often source of large-scale
the source of most blackouts,
blackouts
but these are local
Synchronism
Since most generation is from
synchronous machines, the
interconnected power system
swings together.
16
North American Control Areas