FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention - AN AUTOMATED SYSTEM AND A METHOD FOR
MEASURING VARIOUS PARAMETERS FOR
CIRCUIT BREAKERS
2. Applicant(s)
(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY : An Indian company
(c) ADDRESS : L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be
performed :

FIELD OF THE INVENTION
The present invention relates to an improved automated system for measuring various parameters for circuit breakers. More particularly, the invention relates to an improved automated system for measurement of closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for circuit breakers.
The invention also relates to a method for high precision measurement of closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for circuit breakers.
BACKGROUND AND THE PRIOR ART
In the circuit breakers/air circuit breakers (ACB) drive shaft is the moving part which has moving contacts, when the breaker is closed or opened the shaft rotates, during its rotation the contacts closes at some point of travel and finally shaft stops. During opening similarly the shaft rotates in reverse direction and contacts opens.
US 6472877 discloses a method and apparatus for measuring the opening time of a medium voltage air circuit breaker. Herein the prior art teaches a circuit and method for measuring the opening time of a circuit breaker which minimizes down time of the power distribution system and which is not connected to the main power contacts of the circuit breaker. However, it was not known that closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like can be measured by
2

introducing automation in the system and achieving accurate, reliable and precise measurement.
The conventional system available in the market uses specially designed micro-controller based card and LCD display to measure the parameters. Further there is no graphical representation of measured parameters and no provision for data storage and analysis of historical data
The conventional method of measurement of closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like was time consuming, inconsistent reading, poor reliability and operator dependent.
Thus there is a need to provide for an improved automated system and method for measurement of closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for the circuit breakers and the like.
The present inventors have found that improved measurement of closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like can be achieved and historical trend and analysis of the measured parametric values maintained for circuit breakers and the like by way of a system and a method for interfacing outputs from sensing means and breaker contacts thereby determining the required parameters.
OBJECTS OF THE INVENTION
Accordingly, one object of the present invention is to overcome the disadvantages of the prior art.
3

Another object of the present invention is to provide a system to measure the closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for circuit breakers accurately.
Another object of the present invention is to provide a method for measuring the closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for circuit breakers accurately.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided an automated system to measure various parameters for circuit breakers, said system comprising:
sensing means mounted on shaft of circuit breaker which
contact the parameters to be measured;
converter means being operatively connected to said sensing
means, said converter means adapted to receive inputs from
said sensing means,
data acquisition means for sampling of all signals received
from converter means, said data acquisition means having high
sampling frequency; and
processing means receiving the sampled data from the data
acquisition means wherein the sampled data is processed and
analyzed to get desired parameter values.
According to another aspect of the present invention there is provided a method for measuring various parameters for circuit breakers, method comprising steps of:
4

Sensing of position changes of shaft of the circuit breakers
in form of resistance changes;
converting said resistance changes into potential changes by
means of converter means and communicating the same to a data
acquisition means for sampling wherein all potential changes
are sampled; and
analyzing said sampled data in processing means so as to
extract required information on various parameters for the
circuit breakers.
The other objects and advantages of the present invention will be apparent from the detailed description and the description provided hereinbelow with reference to the accompanying figures.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an automated system for measurement of various parameters for circuit breakers. It is known in the circuit breakers/air circuit breakers (ACB) drive shaft is the moving part which has moving contacts, when the breaker is closed or opened the shaft rotates, during its rotation the contacts closes at some point of travel and finally shaft stops. During opening similarly the shaft rotates in reverse direction and contacts opens.
The system of the present invention facilitates measurement of closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like and combinations thereof. The system of the present invention comprises a sensing means mounted on the shaft of the circuit breakers (herein the circuit breaker is an air circuit breaker) . However, air circuit breaker does not restrict the scope of the present invention and the system of
5

the present invention can be used in any other circuit breakers. The sensing means is a rotary potentiometer mounted on the shaft of the product under test. The mounting of the potentiometer is done in a manner that rotation of shaft makes the potentiometer to rotate and the angle of rotation is transferred to converter means.
The converter means is a signal conditioning module which measures the resistance change of potentiometer in the form of potential change. The breaker contact continuity signal is also converted into potential change. The system further comprises a high speed data acquisition card which receives the data output from the said potentiometer. The data acquisition card used in the present invention has sample frequency upto 100 KHz where each signal is sampled by 10 KHz. However, this sample frequency is not to be considered as restricting the scope of the present invention and any other data acquisition card with high order or lower order of sample frequencies can be used and still the invention can be performed.
The processing means of the present invention receives the sampled data output from the data acquisition means. The captured data is analyzed adopting a computer program. Velocity of the shaft at the point of closing and/or opening of contacts, total angle of rotation, bounce time and number of bounce for the breaker contacts, closing/opening time and re-bounce angle are the parameters derived and displayed on computer screen. Graphical display of all channels is also available to analyze the signal manually.
Data captured is stored in the database for analysis on product and processes. The reference values are also stored in the database, actual values are compared with reference value
6

and OK / not OK decision also given by the software. Additionally, data can be viewed and reproduced graphically in testing station from stored data and can also be analyzed at a remote place. Further the system can be further enhanced through data/screens in HTML format over internet for remote analysis. However, such HTML format should not be considered as restriction of the present invention and any other format can be used and still the invention can be performed.
Another embodiment of the present invention describes a method for measuring closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for circuit breakers. The position changes of contactors are sensed in form of resistance changes. The acquired information/data on the breaker contact travel or position change measured in the form of change in resistance of the potentiometer is then converted into potential changes by means of converter means and communicated to a data acquisition means for sampling wherein all potential changes are sampled. The sampled data/information are then analyzed in a processing means so as to extract required information on closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like for the circuit breakers.
Advantages :
• It gives indication on proper working of mechanism which is heart of the circuit breaker.
• The measurement of the parameters is done in a manner that there is no physical device pushing the shaft of the breaker. So the measurement is true reflection of actual operation.
7

• Correctness of critical items and freeness of moving parts, spring values etc. can be verified in one shot.
• Helps in analyzing effect of change in component or process.
• Historical trend and analysis possible for selected parameters.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 illustrates a block representation of the system of the present invention.
Figure 2 illustrates measurement set up of speed for power breaker.
Figure 3 illustrates measurement set up of speed for power breaker.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 shows the system of the present invention which comprises sensor (1), signal conditioning Module (2), high speed Data Acquisition card (3) and processing means (4). The figure also shows the device for which parameters are required to be measured. Sensor (1) is operatively connected to air circuit breaker (5) .
Figures 2 and 3 indicates the closing speed, number of bounce, time of bounce and closing time for phases (Rl, Yl, Bl, Nl) and (R2, Y2, B2, N2) .
8

The invention has been described in a preferred form only and many variations . may be made in the invention which will still be comprised within its spirit. The invention is not limited to the details cited above. The components herein described may be replaced by its technical equivalence and yet the invention can be performed. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit.
9

WE CLAIM
1. An automated system to measure the various parameters for
circuit breakers, said system comprising:
sensing means mounted on shaft of circuit breaker which
contact the parameters to be measured;
converter means being operatively connected to said
sensing means, said converter means adapted to receive
inputs from said sensing means,
data acquisition means for sampling of all signals
received from converter means, said data acquisition
means having high sampling frequency; and
processing means receiving the sampled data from the data
acquisition means wherein the sampled data is processed
and analyzed to get desired parameter values.
2. System as claimed in claim 1, wherein the sensing means comprises a rotary potentiometer.
3. System as claimed in claims 1 and 2 wherein the various parameters are selected from closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like and combinations thereof.
4. System as claimed in claim 1, wherein the converter means comprises a signal conditioning module.
5. System as claimed in claims 1 to 4 wherein sampled data is optionally remotely analyzed.
10

6. A method for measuring various parameters for circuit
breakers, method comprising steps of:
sensing of position changes of shaft of the circuit
breakers in form of resistance changes;
converting said resistance changes into potential
changes by means of converter means and communicating the
same to a data acquisition means for sampling wherein all
potential changes are sampled; and
analyzing said sampled data in processing means so as to
extract required information on various parameters for
the circuit breakers.
7. Method as claimed in claim 6 further comprising steps of converting breaker contact contact continuity signal to potential change.
8. Method as claimed in claims 6 and 7 wherein the various parameters are selected from closing speed, opening speed angle of rotation, bounce time, number of bounce, closing and opening time, rebounce angle and the like and combinations thereof.
9. Method as claimed in claims 6 to 8 wherein all channels are displayed graphically for analyzing the signals.
10. An automated system and a method to measure the various parameters for circuit breakers as herein described and illustrated with reference to the accompanying figures.
Dated this 26th day of March 2008

11

ABSTRACT
AN AUTOMATED SYSTEM AND A METHOD FOR MEASURING VARIOUS PARAMETERS FOR CIRCUIT BREAKERS
The present invention relates to an automated system to measure various parameters for circuit breakers. The system comprises sensing means (1), converter means (2) operatively connected to the sensing means, data acquisition means (3) for sampling of all signals received from converter means, and processing means (4) receiving the sampled data from the data acquisition means where the sampled data is processed and analyzed to get desired parameter values. The invention also relates to a method for measuring various parameters for circuit breakers.
Figure 1
12