FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule)

TITLE OF THE INVENTION
A system for controlling air flow for cooling for testing of motors.
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Sharma Neeraj of Crompton Greaves Ltd, Machine (M7) Division, D-5, Industrial Area, MPAKVN, Mandideep - 462046, Madhya Pradesh, India, an Indian National.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.

FIELD OF THE INVENTION:
This invention relates to the field of testing mechanisms and equipment for traction motors.
Particularly, this invention relates to a system for controlling air flow for cooling for testing of motors.
BACKGROUND OF THE INVENTION:
A traction motor such as an electric motor includes various types of operational parameters need to be monitored and tested before dispatch. A series/ parallel Hopkinson's test is performed to check these parameters. In this test, two motors of similar rating are put under same conditions and are coupled mechanically. Typically, one motor acts as a motor and other acts as a generator. The inlet air volume (in mm) of water, for cooling, is maintained. This test comprises a plurality of bellows for cooling of motor. The cross section area of the air duct, typically, is 0.1748 m . The air pressure at starting point of bellows and at the end has some variation, which has to be adjusted through air inlet valve as per the requirement.
The following deficiencies, in the existing control, are spotted:
1. Manual damper is used for maintaining the air flow;
2. No control on air flow; and
3. No motor protection against any faults.

OBJECTS OF INVENTION:
An object of the invention is to provide better air flow control through air ducts of traction motors.
Another object of the invention is to eliminate manual intervention for setting air pressure through damper of traction motor.
Yet another object of the invention is to facilitate continuous monitoring of air pressure in air duct of traction motor.
Still another object of the invention is to provide an automated air flow for motors.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a system for controlling air flow for cooling, through air ducts, for testing of motors, said system comprising:
a. pressure sensor in each of said air ducts, adapted to sense pressure of air
through said ducts;
b. drive means adapted to drive controlled amounts of air through said sir
duct in correlation with sensed pressure of air, and required pressure of
air; and
c. processor means adapted to receive said sensed pressure signals, to
compare said pressure signals with pre-defined pressure signals, and to

drive said drives for allowing air through said air ducts to achieve said required air supply to said motors.
Typically, said system includes remotely located control means adapted to control said processing means from a remote location.
Typically, said processing means includes comparator means adapted to compare said sensed signal with said pre-defined pressure signal.
Typically, said drive means is an AC drive means.
Typically, one motor is a generator motor.
Typically, one motor is a driven motor.
Typically, said system includes display means to display said sensed pressure signals.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a typical test setup for testing motors.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a schematic of testing mechanism for testing motors.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Typically, said test is a regenerative test. By this mechanism and method full load test can be carried out on two shunt machines, preferably identical ones without wasting their output. The connection diagram for this test on a pair of shunt machines is shown in Figure 1 of the accompanying drawings.
Typically, the two machines (motors) are mechanically coupled and they are so adjusted that one of them acts as a motor and the other as a generator. The electric power produced by the generator is utilized by the motor which is driving the generator. The power taken from the supply is that required to overcome the losses only. Two identical machines of any size can be tested under full load condition; therefore method is very useful for determining efficiency and also heat run test for determining the temperature rise.
To perform the test, the following procedure is adopted:
Machine M is started through a starter and its field rheostat R2 is adjusted so that it runs at normal speed. The machine M will drive machine G. The switch S is initially kept open.
The excitation of machine G is gradually increased (by decreasing the field circuit resistance) till voltmeter V1 reads zero. Then switch S is closed. Machine G is now floating neither taking any current from the supply nor delivering any current. Any desired load can be put on the set by adjusting the shunt field regulator. The machine with lower excitation will act as a motor and then the other machine will acts as a generator.

The power input to the set is only that which is required to meet the losses. The electrical output of the generator plus the small power taken from the supply is taken in by the motor given out as mechanical power after supplying the motor losses.
V = Supply voltage
11 = Output current of generator
12 = Current taken from supply
13 = Exciting current of generator
14 = Exciting current of motor
Ra=Armature resistance of each machine
The traction machines that are tested in the test plant are tested by creating almost same conditions in which these have to be operated at customer end. Cooling of these motors is done by force ventilation. To perform this operation, blower ducts have been installed which suck the air from outside which acts as inlet for the machines. The air pressure has to be continuously maintained throughout the testing period. To do so, it is necessary to adjust the dampers and measure the air volume in the air duct manually.
According to this invention, there is provided a testing mechanism for testing motors. Typically motors are traction motors (10). Typically, there are provided air ducts (12, 14) from said traction motor, said air ducts being provided for cooling purposes.
Figure 2 illustrates a schematic of testing mechanism for testing motors.

In accordance with an embodiment of this invention, there is provided a pressure sensor (16, 18) in each of said ducts, adapted to sense pressure of air through said ducts.
In accordance with another embodiment of this invention, there is provided a drive means (20, 22) adapted to drive controlled amounts of air through said sir duct. Typically, air control is in correlation with sensed pressure of air, and required pressure of air.
In accordance with yet another embodiment of this invention, there is provided a processor means (24) adapted to receive said sensed pressure signals, to compare said pressure signals with pre-defined pressure signals, and to drive said drives for allowing air through said air ducts to achieve said required air supply to said motors.
In accordance with an additional embodiment of this invention, there is provided a remotely located control means adapted to control said processing means from a remote location.
This eliminates manual intervention of setting the air pressure through damper, as was required in the prior art. The system of this invention will also facilitate continuous monitoring of air pressure in air duct.

We claim:
1. A system for controlling air flow for cooling, through air ducts, for testing of at least two motors, said system comprising:
a. pressure sensor in each of said air ducts, adapted to sense pressure of air
through said ducts;
b. drive means adapted to drive controlled amounts of air through said sir
duct in correlation with sensed pressure of air, and required pressure of
air; and
c. processor means adapted to receive said sensed pressure signals, to
compare said pressure signals with pre-defined pressure signals, and to
drive said drives for allowing air through said air ducts to achieve said
required air supply to said motors.
2. A system as claimed in claim 1 wherein, said system includes remotely located control means adapted to control said processing means from a remote location.
3. A system as claimed in claim 1 wherein, said processing means includes comparator means adapted to compare said sensed signal with said predefined pressure signal.
4. A system as claimed in claim 1 wherein, said drive means is an AC drive means.
5. A system as claimed in claim 1 wherein, one motor is a generator motor.

6. A system as claimed in claim 1 wherein, one motor is a driven motor.
7. A system as claimed in claim 1 wherein, said system includes display means to display said sensed pressure signals.