18-06-2012, 03:11 PM
Power upgrading of Transmission Line by combining
AC-DC Transmission
Power upgrading of Transmission.pdf (Size: 613.49 KB / Downloads: 160)
Abstract:
Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep
sufficient margin against transient instability. With the scheme proposed in this project, it is possible to load these
lines very close to their thermal limits. The conductors are allowed to carry usual ac along with dc superimposed
on it.
The added dc power flow does not cause any transient instability. This paper gives the feasibility of converting a
double circuit ac line into composite ac–dc power transmission line to get the advantages of parallel ac–dc
transmission to improve stability and damping out oscillations.
Introduction:
In recent years,
environmental, right-of-way, and cost concerns have
delayed the construction of a new transmission line,
while demand of electric power has shown steady
but geographically uneven growth. The power is
often available at locations not close to the growing
load centers but at remote locations. These locations
are largely determined by regulatory policies,
environmental acceptability, and the cost of
available energy. The wheeling of this available
energy through existing long ac lines to load centers
has a certain upper limit due to stability
considerations. Thus, these lines are not loaded to
their thermal limit to keep sufficient margin against
transient instability.
Problem Definition:-
The main object of my paper is to show that by
superimposing DC in AC transmission, the capacity
of the transmission line can be increased by nearly
70 % of that if only AC is transmitted. In our
existing transmission system, long extra high
voltage (EHV) ac lines cannot be loaded to their
thermal limits in order to keep sufficient margin
against transient instability. With the scheme
proposed in this project, it is possible to load these
lines very close to their thermal limits. The
conductors are allowed to carry usual ac along with
dc superimposed on it.
High Voltage AC Transmission
Introduction:-
Industrial-minded countries of the world require a
vast amount of energy of which electrical energy
forms a major fraction. The world has already
consumed major portion of its natural resources and
is looking for sources of energy other than Hydro
and Thermal to cater for the rapid rate of
consumption which is outpacing the discovery of
new resources. This will not slow down with time
and therefore there exists a need to reduce the rate of
annual increase in energy consumption by any
intelligent society if resources have to be preserved
for posterity. This requires very high voltages for
transmission. The very rapid stride taken by
development of dc transmission since 1950 is
playing a major role in extra-long-distance
transmission, complementing or supplementing
E.H.V. ac transmission. They have their roles to
play and a country must make intelligent assessment
of both in order to decide which is best suited for the
country's economy.
Conclusion
The feasibility to convert ac transmission line to a
composite ac–dc line has been demonstrated. For the
particular system studied, there is substantial
increase (about 83.45%) in the loadability of the
line. The line is loaded to its thermal limit with the
superimposed dc current.
AC-DC Transmission
Power upgrading of Transmission.pdf (Size: 613.49 KB / Downloads: 160)
Abstract:
Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep
sufficient margin against transient instability. With the scheme proposed in this project, it is possible to load these
lines very close to their thermal limits. The conductors are allowed to carry usual ac along with dc superimposed
on it.
The added dc power flow does not cause any transient instability. This paper gives the feasibility of converting a
double circuit ac line into composite ac–dc power transmission line to get the advantages of parallel ac–dc
transmission to improve stability and damping out oscillations.
Introduction:
In recent years,
environmental, right-of-way, and cost concerns have
delayed the construction of a new transmission line,
while demand of electric power has shown steady
but geographically uneven growth. The power is
often available at locations not close to the growing
load centers but at remote locations. These locations
are largely determined by regulatory policies,
environmental acceptability, and the cost of
available energy. The wheeling of this available
energy through existing long ac lines to load centers
has a certain upper limit due to stability
considerations. Thus, these lines are not loaded to
their thermal limit to keep sufficient margin against
transient instability.
Problem Definition:-
The main object of my paper is to show that by
superimposing DC in AC transmission, the capacity
of the transmission line can be increased by nearly
70 % of that if only AC is transmitted. In our
existing transmission system, long extra high
voltage (EHV) ac lines cannot be loaded to their
thermal limits in order to keep sufficient margin
against transient instability. With the scheme
proposed in this project, it is possible to load these
lines very close to their thermal limits. The
conductors are allowed to carry usual ac along with
dc superimposed on it.
High Voltage AC Transmission
Introduction:-
Industrial-minded countries of the world require a
vast amount of energy of which electrical energy
forms a major fraction. The world has already
consumed major portion of its natural resources and
is looking for sources of energy other than Hydro
and Thermal to cater for the rapid rate of
consumption which is outpacing the discovery of
new resources. This will not slow down with time
and therefore there exists a need to reduce the rate of
annual increase in energy consumption by any
intelligent society if resources have to be preserved
for posterity. This requires very high voltages for
transmission. The very rapid stride taken by
development of dc transmission since 1950 is
playing a major role in extra-long-distance
transmission, complementing or supplementing
E.H.V. ac transmission. They have their roles to
play and a country must make intelligent assessment
of both in order to decide which is best suited for the
country's economy.
Conclusion
The feasibility to convert ac transmission line to a
composite ac–dc line has been demonstrated. For the
particular system studied, there is substantial
increase (about 83.45%) in the loadability of the
line. The line is loaded to its thermal limit with the
superimposed dc current.