Electric
Springs—A New Smart Grid Technology
ABSTRACT:
The scientific principle of “mechanical springs” was
described by the British physicist Robert Hooke in the 1660’s. Since then, there
has not been any further development of the Hooke’s law in the electric regime.
In this paper, this technological gap is filled by the development of “electric
springs.” The scientific principle, the operating modes, the limitations, and
the practical realization of the electric springs are reported. It is
discovered that such novel concept has huge potential in stabilizing future
power systems with substantial penetration of intermittent renewable energy sources.
This concept has been successfully demonstrated in a practical power system
setup fed by an ac power source with a fluctuating wind energy source. The
electric spring is found to be effective in regulating the mains voltage
despite the fluctuation caused by the intermittent nature of wind power.
Electric appliances with the electric springs embedded can be turned into a new
generation of smart loads, which have their power demand following the power
generation profile. It is envisaged that electric springs, when distributed
over the power grid, will offer a new form of power system stability solution
that is independent of information and communication technology.
KEYWORDS:
1. Distributed power systems
2. Smart loads
3. Stability
SOFTWARE: MATLAB/SIMULINK
BLOCK
DIAGRAM:
Fig. 1. The experimental setup for the
electric spring (with control block diagram).
CONCLUSION:
The Hooke’s law on mechanical springs has
been developed into an electric spring concept with new scientific applications
for modern society. The scientific principles, operating modes and limits of
the electric spring are explained. An electric spring has been practically
tested for both voltage support and suppression, and for shaping load demand
(of about 2.5 kW) to follow the fluctuating wind power profile in a 10 kVA
power system fed by an ac power source and a wind power simulator. The electric
springs can be incorporated into many existing noncritical electric loads such
as water heaters and road lighting systems [26] to form a new generation of
smart loads that are adaptive to the power grid. If many noncritical loads are
equipped with such electric springs and distributed over the power grid, these electric
springs (similar to the spring array in Fig. 1) will provide a highly reliable
and effective solution for distributed energy storage, voltage regulation and
damping functions for future power systems. Such stability measures are also
independent of information and communication technology (ICT). This discovery
based on the three-century-old Hooke’s law offers a practical solution to the
new control paradigm that the load demand should follow the power generation in
future power grid with substantial renewable energy sources. Unlike traditional
reactive power compensation methods, electric springs offer both reactive power
compensation and real power variation in the noncritical loads. With many countries
determined to de-carbonize electric power generation for reducing global
warming by increasing renewable energy up to 20% of the total electrical power
output by 2020 [22]–[25], electric spring is a novel concept that enables human
society to use renewable energy as nature provides. The Hooke’s law developed in
the 17th century has laid down the foundation for stability control of
renewable power systems in the 21st century.
REFERENCES:
[1] Hooke’s
law—Britannica Encyclopedia [Online]. Available: http://www.britannica.com/EBchecked/topic/271336/Hookes-law
[2]
A. M. Wahl, Mechanical Springs, 2nd ed. New York: McGraw-Hill, 1963.
[3]
W. S. Slaughter, The Linearized Theory of Elasticity. Boston, MA: Birkhauser,
2002.
[4]
K. Symon, Mechanics. ISBN 0-201-07392-7. Reading, MA: Addison- Wesley,
Reading,1971.
[5]
R. Hooke, De Potentia Restitutiva, or of Spring Explaining the Power of
Springing Bodies. London, U.K.: John Martyn, vol. 1678, p. 23.
