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he century-old U.S. electricity
grid is said to be the largest
interconnected machine on Earth.
The grid comprises more than 9,200
generating units producing over 1,000
GW and connected to more than
480,000 km of transmission lines.
However, at no time in its history has
this grid undergone such rapid change
as that which is happening now.
Utilities are investing heavily in “smart
grids” to dramatically enhance energy
delivery by lowering costs, improving
efficiency, offering customers more
flexibility, and making the connecting of
renewable energy sources easier.
Implementing smart grids demands a
range of new technologies including grid
protection, power quality enhancement,
fast communications, cyber security,
and consumer monitoring. That makes
these huge machines increasingly
reliant on the electronic components
that have supported the technology
revolution already experienced by many
other sectors.
This article looks at the opportunities
that are opening up for electronics
designers as smart grids gather pace
and then describes a range of modules
from major suppliers that have been
specifically designed to power the
electronic systems, satisfying the
unique challenges of these new
electricity networks.
Power revolution
The smart-grid revolution has been
triggered by a number of factors,
including consumer backlash to rising
prices, increased raw-energy costs,
deregulation, and pressure from
the environmental lobby to limit the
construction of new fossil-fuel power
stations. The disruption is bringing
computerization, digital communication,
and bi-directional energy flow to a
previously ultra-conservative industry
in order to dramatically enhance the
performance of its networks.
While the smart grid is complex, it
can be broken down into four key
areas: Infrastructure, communications,
metering, and renewable energy.
Engineers tasked with upgrading
existing infrastructure to smart-grid
status are in turn concerned with
protection, monitoring, and power
quality. Apart from the wires and
poles, that infrastructure comprises
“distribution automation” resources
equipped with sensors to gather data,
sending information about the grid’s
status and performance to the utility’s
network operations center to allow
operators to adjust and control assets
from the central location. In addition,
smart grids automatically monitor,
protect, and optimize electricity
distribution to industrial users and
domestic consumers. The built-in
intelligence of smart grids also allows
rapid automatic intervention in the case
of faults, limiting outage duration.
Another key difference between a smart
grid and a conventional network is that
electricity flows in both directions,
which enables utilities to move away
from centralized power generation and
encourage distributed renewable energy
sources such as wind turbines and
photovoltaic (PV) panels on domestic
consumers’ roofs (Figure 1). Smart
grids also limit system losses, thus
improving overall efficiency and helping
to decrease the generation of carbon
emissions and other pollutants[1].
Smart-grid information systems
include Power Line Communications
(PLC), Ethernet networks, serial links,
T
Power Modules Underpin Smart Grid Adoption
Steven Keeping, DigiKey Electronics
New-Tech Magazine Europe l 28