FIELD OF APPLICATION
The present invention relates to a system for obtaining power from an
alternative source during short duration power disturbances.
In particular, it relates to using a high power static transfer switch for obtaining
power from an alternative source during power disturbances like, voltage dips.
BACKGROUND OF THE INVENTION
Power disturbances, like voltage dips may lead to stoppage of a plant resulting in
disruption in production, affecting quality of output and also equipment damage.
A voltage dip of 30 % of the line voltage in one or all of the three phases for a
period of 100 m sec and generally less than 1 second may lead to such a
stoppage of plant with widespread effect.

The existing practice for avoiding such unpredictable happening despite various
measures taken is to provide an uninterrupted power supply (UPS) for protecting
costly equipment like PLC, etc.
However, UPS are available only upto about 100 KW because of the cost factor.
The cost of more than 100 KW UPS may be prohibitively high and above 150 KW
range it may not be available at all.
One possible solution for high power systems may be a reserved energy
flywheel. The cost of one 5 MW unit may be as high as Rs. 30 crores.
There was therefore, a need to provide a more cost effective solution to ensure
protection of high power (in MW) devices during short power disturbances.

SUMMARY OF THE INVENTION
The main object of the present invention therefore, is to provide megawatt
power from an alternate source for short duration of say 2 seconds to the system
affected with power disturbance and revert back to the main source after
ensuring that the disturbance is over.
This and other objects of the present invention are achieved by providing a fast
switching static switch to handle the megawatt power during switch over to an
alternate source in the event of a power disturbance and reverting back to the
main supply source after normalcy is restored.
Thus the present invention provides a system for obtaining megawatt power
from a geographically apart alternative source during short duration power
disturbances, said system comprising a fast switching static switch capable of
supplying megawatt power from said alternative source during the disturbance
and reverting back to main supply source upon restoration of normalcy.

BREIF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention can now be described in detail with the help of the figures of the
accompanying drawings in which
Figure 1 shows schematically an existing system for a high power device
without protection against power disturbances.
Figure 2 shows an existing system where UPS is provided
to protect expensive low power equipment like PLC.
Figure 3 shows the system of Figure 2 where the
present invention has been applied.

DETAILED DESCRIPTION
The system of a high power load connected to the main power source through a
drive is shown in Figure 1. The system is without protection during any short
duration power disturbance like voltage dip. Drive 2 for load 3 is directly
connected to the main power line 1.
A protection provided in the form of an uninterrupted power supply 2 for costly
equipment like a programmable logic controller 3 is shown in Figure 2.
Figure 3 illustrates the system of the present invention where a fast switching
static switch 4 is used for providing MW power from an alternative source 1' in a
geographically apart area for 2 seconds, in case of any short duration power
disturbance.
The static switch 4 can be of the required MW capacity, fast acting (5 milli
second). The phase and synchronization has to be maintained.

WE CLAIM
1. A system for obtaining megawatt power from a geographically apart
alternative source during short duration power disturbances, said system
comprising a fast switching static switch capable of supplying megawatt
power from said alternative source during the disturbance and reverting
back to main supply source upon restoration of normalcy.
2. The system as claimed in claim 1, wherein said short duration power
disturbance is for a period of about 2 seconds.
3. The system as claimed in claim 1, wherein said fast switching static
switch is of required MW capacity and capable of switching on and
switching off in about 5 milli seconds.

4. A system for obtaining megawatt power from a geographically apart
alternative source, substantially as herein described and illustrated in the
accompanying drawings.

The main object of the present invention therefore, is to provide megawatt
power from an alternate source for short duration of say 2 seconds to the system
affected with power disturbance and revert back to the main source after
ensuring that the disturbance is over.
This and other objects of the present invention are achieved by providing a fast
switching static switch to handle the megawatt power during switch over to an
alternate source in the event of a power disturbance and reverting back to the
main supply source after normalcy is restored.
Thus the present invention provides a system for obtaining megawatt power
from a geographically apart alternative source during short duration power
disturbances, said system comprising a fast switching static switch capable of
supplying megawatt power from said alternative source during the disturbance
and reverting back to main supply source upon restoration of normalcy.