Description:FIELD OF THE INVENTION
[001] The present invention generally relates to a current multiplier and more particularly to a system and method thereof, for AC/DC current multiplier solution to calibrate AC/DC clamp meters and current transformers.
BACKGROUND OF THE INVENTION
[002] AC high current measurement is performed using current transformer (CT). CT manufacturers specify the ratio of CT (Primary current: Secondary Current). If ratio is 2000:5 means primary is rated for 2000A and secondary for 5A. High current flowing through primary will electromagnetically induce proportionate current as per the CT ratio in the secondary throughout the measurement range. User measures secondary current and interprets the actual high current flowing through the primary using the CT ratio. CTs are of different types: ring, ovel, rectangular, split core, clamp type etc.
[003] CT is mostly used for current measurement therefore major concern always is of CT ratio. Applications like Power & Energy measurement where power factor (Cos₵) is to be measured require a measurement of perfect phase angle between voltage and current. It is expected that ideally CT itself should not add any phase error. Manufacturers of CT specify the phase error and ratio error. Ratio error is expressed in terms of class. Where class defines error in terms of Full Scale e.g. CT of 2000A with class 1 accuracy means error of 20A (1% of 2000) is allowed throughout the range. This allowable error is very significant at lower range of measurements. If the same CT is measuring 100A then the allowable error of 20A will effectively be with accuracy of 20%.
[004] As CT tends to be non-linear in performance, they come in different ratings of ratios and class of accuracy. Therefore, for a low current measurement applications CT with Full scale of that current value is chosen.
[005] CTs used for either current measurement or power/ energy analysis should periodically be calibrated. CT calibration set up requires AC High Current source, ratio and phase error analyzer and a Reference CT. CT to be calibrated is compared with the reference CT for its ratio and phase errors.
[006] Reference CT needs to be calibrated from a better lab like National Physical Laboratory. There are three techniques of making a High Current Source to excite the CT under calibration:
1. Variac (dimmer stat/auto transformer) along with transformer of high current
2. Amplifier with transformer of high current with feedback control system
3. Stable and adjustable low current source with current multiplier coil.
[007] Figure 1 (prior art) shows high current source using Variac (dimmer stat/auto transformer) along with transformer of high current. Figure 2 (prior art) shows high current source using Amplifier with transformer of high current with feedback control system. Figure 3 (prior art) shows high current source using stable and adjustable Low current source derived from current ranges of Multi-Function Calibrator with current multiplier coil to simulate High current.
[008] However, Variac controlled current sources have poor stability. Current tends to vary as per mains variations. Heavy current cause heating effect and hence cable resistance increases and the current tends to drop.
[009] The Amplifier based technology needs higher wattage amplifiers and high current transformers too! heavy current cause heating effect and hence cable resistance increases and therefore more power is demanded from the input to maintain the set current. Further, heating effect due to a very high current attracts more electricity bill.
[0010] Also, Reference CT whose characteristics of ratio error and phase error are defined over the entire range is required for CT under calibration to be compared with it. Both (Variac based and Amplifier based) techniques need the Reference CT. As CTs of different current ratings required to be calibrated therefore the above two techniques need multiple outputs of current ranges. Therefore, multiple Reference CTs also! These CTs need to be calibrated from prime labs like NPL. It is very expensive and time consuming to maintain calibration traceability of all the reference CTs.
[0011] Further, both (Variac based and Amplifier based) techniques tend to be very bulky in size. Cables with suitable end terminations/lugs capable of handling extremely high currents are required for making connections. Special tools like spanners, nuts, bolts, washers etc. needed to make and break connections of reference CT and CT under calibration and that too for each output range. Current Multipliers normally come with multi-function calibrators to calibrate camp meters and clamp CTs. Current Multipliers cannot calibrate normal CTs (Ring, Toroidal, rectangular) type because of their construction limitations.
[0012] For the reasons stated above, which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for a system and method thereof for an AC/DC current multiplier that will serve as a stable and accurate high current simulator to calibrate both CTs and Clamps that is useable, scalable and independent of new technology platforms, uses minimum resources that is easy and cost effectively maintained and is portable and can be deployed anywhere in very little time.
SUMMARY OF THE INVENTION
[0013] The present invention generally relates to a current multiplier and more particularly to a system and method thereof, for AC/DC current multiplier solution to calibrate AC/DC clamp meters and current transformers.
[0014] The present invention, a system for AC/DC current multiplier is comprising of a plurality of connector having a plurality of pins (N) each. Each of the connector is having a plurality of pins (N) in the upperpart of the connector and equal number of pins (N) to that of the pins in the upperpart of the connector, in the lower part of the connector is configured to make number of loops equal to one less than number of pins in the connector (N – 1). The first loop begins from pin one of the upper part of the connector and ends at pin two of the lower part of the connector, the second loop begins from pin two of the upper part of the connector and ends pin three of the lower part of the connector and so on, making effectively number of loops equal to one less than number of pins in the connector (N – 1) per connector. The present invention a system for AC/DC current multiplier is comprising of a plurality of flexible insulated copper wires to form loops. The number of flexible insulated copper wires forming loops being equal to one less than number of pins in the connector (N – 1) flexible insulated copper wires per connector constituting the system. The present invention a system for AC/DC current multiplier is comprising of a make/break arrangement configured through connector ensuring firm connection of same pin numbers of upperpart and lower part when fit together. The present invention a system for AC/DC current multiplier wherein the current is fed to the pin one of the lower part of the first connector and return path of the current is taken from the last pin of the lower part of the first connector constituting a current multiplier of X (one less than number of pins in the connector (N – 1)). The present invention a system for AC/DC current multiplier wherein the current multiplier of X(one less than number of pins in the connector (N – 1)) connections are replicated for required number of X(one less than number of pins in the connector (N – 1)) current multiplication and last pin of a connector is connected to first pin of the very next connector to connect all the loops from all the connector in series when all connectors are fitted. The present invention a system for AC/DC current multiplier is comprising of a rotary switch. The rotary switch comprising one pole and plurality of ways, the number of the plurality of ways being equal to the number of connectors constituting the system. The present invention a system for AC/DC current multiplier wherein a junction point of a previous connector’s last pin and the first pin of the very next connector connected sequentially to one of the plurality of ways of the multi-way single pole rotary switch, and a pole of the rotary switch connected to low potential point of a current source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The embodiments can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the embodiments. Moreover, the figures, like reference numerals designate corresponding parts throughout the different views.
[0016] Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[0017] The above and other objects, features, and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Figure 1 (prior art) shows high current source using Variac (dimmer stat/auto transformer) along with transformer of high current.
Figure 2 (prior art) shows high current source using Amplifier with transformer of high current with feedback control system.
Figure 3 (prior art) shows high current source using stable and adjustable Low current source derived from current ranges of Multi-Function Calibrator with current multiplier coil to simulate High current.
Figure 4 illustrates the Amp-Turns (AT) realization as a product of current and number of turns.
Figure 5 (prior art) illustrates a set up for Clamp Meter calibration.
Figure 6(A-B) and Figure 7 illustrates an exemplary implementation of the system for AC/DC current multiplier according to one of the embodiments of the present invention.
Figure 8 illustrates an AC/DC Current Multiplier Coil having accommodated CT and Clamp Meter according to one of the embodiments of the present invention.
Figure 9 illustrates a circuit diagram explaining how 10 loops per connecter are added and all connectors connected in series according to one of the embodiments of the present invention.
Figure 10 A-AD illustrates test setup for AC current for the system and method thereof for AC/DC current multiplier according to one of the embodiments of the present invention.
Figure 11 A-T illustrates test setup for DC current for the system and method thereof for AC/DC current multiplier according to one of the embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is a system/device and method thereof related to a current multiplier and more particularly to a system and method thereof, for AC/DC current multiplier solution to calibrate AC/DC clamp meters and current transformers.
[0019] In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, some of which are described below, may be incorporated into a number of systems.
[0020] The various embodiments of the present invention provide a system/device and method thereof for AC/DC current multiplier solution to calibrate AC/DC clamp meters and current transformers.
[0021] Furthermore, connections between components and/or modules within the figures are not intended to be limited to direct connections. Rather, these components and modules may be modified, re-formatted or otherwise changed by intermediary components and modules.
[0022] The systems/device and methods described herein are explained using examples with specific details for better understanding. However, the disclosed embodiments can be worked on by a person skilled in the art without the use of these specific details.
[0023] Throughout this application, with respect to all reasonable derivatives of such terms, and unless otherwise specified (and/or unless the particular context clearly dictates otherwise), each usage of:
“a” or “an” is meant to read as “at least one.”
“the” is meant to be read as “the at least one.”
References in the present invention to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
[0024] Embodiments of the present invention include various steps, which will be described below. The steps may be performed by mechanical, magnetic, electrical components or may be embodied in a mechatronic system, machine-executable instructions, which may be used to cause a general-purpose or special purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of mechanical, magnetic, electrical components and/or by human operators.
[0025] If the specification states a component or feature "may' can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0026] As used in the description herein and throughout the claims that follow, the meaning of "a, an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.
[0027] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this invention will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).
[0028] Hereinafter, embodiments will be described in detail. For clarity of the description, known constructions and functions will be omitted. Parts of the description may be presented in terms of operations performed by a Mechanical/Magnetic/Electrical/Electronic system.
[0029] While embodiments of the present invention have been illustrated and described, it will be clear that the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the invention, as described in the claim.
[0030] The present invention, a system and method thereof for AC/DC current multiplier is based on the principle of current multiplication. A Current Transformer (CT) is an electrical device that measures alternating current (AC) in a primary circuit and provides a proportional reduced current in a secondary circuit as per CT ratio.
[0031] Clamp-on Current Transformers (Clamp CTs) are portable devices that measure current without interrupting the primary circuit. The Hall Effect sensor type clamps sense DC currents too!
[0032] The conductor (bus bar or cable) carrying high current is routed through CT to monitor the current. The conductor itself serves the purpose of primary of a CT. The current carrying conductor produces magnetic field around it. The change in flux linkages induce emf and thereby the current is induced in the secondary of CT as per the CT ratio. But CT actually measures Amp-Turns. Amp-Turns (AT) is a unit of Magneto Motive Force (MMF). It is a product of current and number of turns.
[0033] If CT is subjected to measure 300A flowing through a straight single conductor then it will sense current as per the Magneto Motive Force of 300 Amp-Turns (AT). If the two loops are passing through the same CT then it will experience 300 Amp-Turns (AT) at 150 A because of the two turns. Similarly, if the three loops are passing through the same CT then CT will sense 300 AT at 100A.
[0034] The Figure 4 illustrates the Amp-Turns (AT) realization as a product of current and number of turns. Current Multiplication is nothing but creating Amp-Turns using a low current source. It is illustrated in Figure 4, as you increase number of turns effectively you increase primary turns and therefore the overall CT ratio is reduced or in practice current requirement is reduced to calibrate the CT. There will be always limitation to pass multiple loops through CT manually.
[0035] Leading manufacturers of Multi-Function/Product Calibrators supply the Current Multiplier Coils for exclusively calibration of Clamp Meters. A Coil having typically 100 loops is made from a single unbroken enamelled copper wire. The loops are made so as to accommodate clamp meters. AC & DC Current (0 to 10A) from Multifunction Calibrator serve the purpose of stable and accurate current source.
[0036] Figure 5 (prior art) illustrates a set up for Clamp Meter calibration. As illustrated in Figure 5, together Coil and current source make a set up for Clamp Meter calibration up to 1000A AC & DC. In this set up Designer has to make a low current source for simulation of High Currents. The Current input to multiplier can either be AC or DC and clamp meters having measurement range even beyond 1000A can also be calibrated. In case of this setup the stability of the simulated high value Amp-Turns (AT) is same as that of the low-level input current and waveform of the simulated high value Amp-Turns (AT) is also same as that of the input current. However, because of the construction limitations, CTs (Ring/ovel/rectangular type) cannot be inserted in above multiplier coil for calibration purpose. Hence current multiplier coils cannot be used for CT calibration.
[0037] According to one of the embodiments, the present invention provides a unique solution which takes care of CT calibration and AC-DC Clamp calibration as well. The system and method thereof of the present invention makes changes in current multiplication technique so as to accommodate CT as well as clamps of different ratios and sizes for their calibration.
[0038] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier is comprising of a plurality of connector having a plurality of pins (N) each. Each of the connector is having a plurality of pins (N) in the upperpart of the connector and equal number of pins (N) to that of the pins in the upperpart of the connector, in the lower part of the connector is configured to make number of loops equal to one less than number of pins in the connector (N – 1). The first loop begins from pin one of the upper part of the connector and ends at pin two of the lower part of the connector, the second loop begins from pin two of the upper part of the connector and ends pin three of the lower part of the connector and so on, making effectively number of loops equal to one less than number of pins in the connector (N – 1) per connector. The present invention a system for AC/DC current multiplier is comprising of a plurality of flexible insulated copper wires to form loops. The number of flexible insulated copper wires forming loops being equal to one less than number of pins in the connector (N – 1) flexible insulated copper wires per connector constituting the system. The present invention a system for AC/DC current multiplier is comprising of a make/break arrangement configured through connector ensuring firm connection of same pin numbers of upperpart and lower part when fit together. The present invention a system for AC/DC current multiplier wherein the current is fed to the pin one of the lower part of the first connector and return path of the current is taken from the last pin of the lower part of the first connector constituting a current multiplier of X (one less than number of pins in the connector (N – 1)). The present invention a system for AC/DC current multiplier wherein the current multiplier of X(one less than number of pins in the connector (N – 1)) connections are replicated for required number of X(one less than number of pins in the connector (N – 1)) current multiplication and last pin of a connector is connected to first pin of the very next connector to connect all the loops from all the connector in series when all connectors are fitted. The present invention a system for AC/DC current multiplier is comprising of a rotary switch. The rotary switch comprising one pole and plurality of ways, the number of the plurality of ways being equal to the number of connectors constituting the system. The present invention a system for AC/DC current multiplier wherein a junction point of a previous connector’s last pin and the first pin of the very next connector connected sequentially to one of the plurality of ways of the multi-way single pole rotary switch, and a pole of the rotary switch connected to low potential point of a current source.
[0039] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier for calibrating CT, users have to lose the connector and fit it after insertion.
[0040] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier the each connector of plurality of pins (N) together with flexible insulated copper wires equal in number to one less than number of pins in the connector (N – 1) forming loops constitutes a current multiplier of X(one less than number of pins in the connector (N – 1)) with make/brake arrangement. The reliable assembly of connector ensures firm connection of same pin numbers of upper part and lower part when fit together.
[0041] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier a low current source can be used for simulation of High current. The current input to current multiplier can either be AC or DC. By the system for AC/DC current multiplier according to present invention clamp meters having measurement range even beyond 1000A can be calibrated.
[0042] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier, the stability of the simulated high value Amp-Turns (AT) is same as that of the low-level input current.
[0043] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier, the current multiplier is configured to accommodate CT as well as clamps of different ratios and sizes for their calibration. The current multiplier is configured for multiple ranges of CT calibration by taping junction points of connector to connector and providing return path of current source through a rotary switch of a plurality of ways and one pole.
[0044] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier, the need of master CT with very high current source is eliminated. The system for AC/DC current multiplier of the present invention does not add any phase error to the simulated AT with respect to basic low current.
[0045] In an implementation according to one of the embodiments of the present invention a system for AC/DC current multiplier, the plurality of connector having a plurality of pins (N) each can be circular connector type, or rectangular connector type, or square connector type or connector made up of any other shape and type.
[0046] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier is comprising of a plurality of connector having eleven pins each. Each of the connector is having eleven pins in the upperpart of the connector and eleven pins in the lower part of the connector. Each of the connector is configured to make ten loops wherein the first loop begins from pin one of the upper part of the connector and ends at pin two of the lower part of the connector, the second loop begins from pin two of the upper part of the connector and ends pin three of the lower part of the connector and so on, making effectively ten loops per connector.
[0047] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier is comprising of a plurality of flexible insulated copper wires to form loops. The number of plurality of flexible insulated copper wires forming loops are equal to ten flexible insulated copper wires per connector constituting the system.
[0048] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier is comprising of a make/break arrangement configured through connector ensuring firm connection of same pin numbers of upperpart and lower part when fit together.
[0049] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier current is fed to the pin one of the lower part of the first connector and return path of the current is taken from the pin eleven of the lower part of the first connector constituting a current multiplier of X10. The current multiplier of X10 connection is replicated for required number of X10 current multiplication and last pin of a connector is connected to first pin of the very next connector to connect all the loops from all the connector in series when all connectors are fitted.
[0050] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier is comprising of a rotary switch comprising one pole and plurality of ways, the number of the plurality of ways being equal to the number of connectors constituting the system. The junction point of a previous connector’s last pin and the first pin of the very next connector are connected sequentially to one of the plurality of ways of the multi-way single pole rotary switch and a pole of the rotary switch connected to low potential point of a current source.
[0051] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier wherein each connector of plurality of pins together with flexible insulated copper wires equal in number to number of pins on connector -1 forming loops constitutes a current multiplier of X10 with make/brake arrangement. Each connector of eleven pins together with ten flexible insulated copper wires forming ten loops constitutes a current multiplier of X10 with make/brake arrangement.
[0052] Figure 6(A-B) and Figure 7 illustrates an exemplary implementation of the system for AC/DC current multiplier according to one of the embodiments of the present invention.
[0053] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier instead of enamelled copper wire, flexible insulated copper wire is used to form loops. Circular connector of 11 pins is used to make 10 loops. The first loop will begin from pin 1 of upper part and end at pin 2 of the lower part. The second loop will begin from pin 2 of upper part and end at pin3 of the lower part and so on. Effectively 10 loops per connector are made. The reliable assembly of circular connector ensures firm connection of same pin numbers of upper part and lower part when fit together. That helps in making total 10 unbroken loops when connector is tightened. To calibrate CT, user has to lose the circular connector and fit it after insertion.
[0054] In an exemplary implementation according to one of the embodiments the system for AC/DC current multiplier wherein if the current is fed to the pin1 of the lower part of the connector and the return path of current is taken from the pin 11 of the lower part of the connector, then effectively, a current multiplier of X10 is made with make / break arrangement.
[0055] In an exemplary implementation according to one of the embodiments of the system for AC/DC current multiplier, 10 loops and a current source of 10A will serve CT/clamp calibration up to 100A AC and DC. To expand the range up to 1000A there should be total 10 connectors i.e., 100 loops i.e. (10A x 100 Turns=1000AT). The last pin of a connector if connected to first pin of very next connector then effectively all the loops will be in series when all connectors are fit. If we tap junction points of connector to connector and provide return path of current source through a rotary switch of 1 pole 10 way then effectively, the system have multiple ranges of CT calibration e.g., 100A, 200A, 300A, 400A, 500A, 600A, 700A, 800A, 900A, 1000A. The system can fit CT, clamp meter or even both to calibrate them.
[0056] Figure 8 illustrates an AC/DC Current Multiplier Coil having accommodated CT and Clamp Meter according to one of the embodiments of the present invention.
[0057] Figure 9 illustrates a circuit diagram explaining how 10 loops per connecter are added and all connectors connected in series according to one of the embodiments of the present invention. This circuit explains how 10 loops per circular connector are added. All the connectors are in series. The junction point of a previous connector's last pin and the first pin of the very next connector are connected to ways of the 10-way single pole switch. The pole of the rotary switch reaches to low potential point of the current source.
[0058] Figure 10 A-AD illustrates test setup for AC current for the system and method thereof for AC/DC current multiplier according to one of the embodiments of the present invention.
[0059] Figure 11 A-T illustrates test setup for DC current for the system and method thereof for AC/DC current multiplier according to one of the embodiments of the present invention.
[0060] The test reports for the system and method thereof for AC/DC current multiplier are depicted in the tables below:

Test Report
Date of Testing Date of Issue Report No.
18-21/01/2025 25/01/2025 01/01 (2024-2025)
1 Name of Customer : M/s: Zeal Manufacturing and Calibration Services Pvt. Ltd. S.No. 78/1, Pandhari Industrial Estate, Shivane, Pune 411023.
2 Calibration/Testing Carried out at : Testing Laboratory
3 Date of Receipt of Item : 17/01/2025
4 Condition of the Item : Okay
5 Prototype Details
Nomenclature: AC/DC Current Multiplier Make: Zeal Model: ZMADCM
6 Environmental Conditions : At Temperature 25C  2C, Humidity 30% - 75 % RH
7 Parameter to be calibrated : AC Current, DC Current
8 Details of traceability used for Calibration/Testing:
Name Make/ Model Sr.No./ Id.No. Calibration Cert. No. & Date Calibrated By
6½ Digit Precision Multimeter Fluke / 8846A 3547023 / ZS/DMM/08 CC/ECL/0890/24-25 09/09 to 10/09/2024 IDEMI, Mumbai
6½ Digit Precision Multimeter Fluke / 8846A 4809019/ ZS/DMM/01 08/128 (2024-2025)
17/08/2024 ZMCSPL, Pune
Current Transformer ETC Corp / --- 2907-02 / ZS/CT/01 12/203 (2024-2025)
27/12/2024 ZMCSPL, Pune
AC/DC Clamp Meter Kyoritsu / Kew Snap 2003A E8233886 / ZS/CLM/02 CC/ECL/1484/24-25 04/01/2025 IDEMI, Mumbai

OBSERVATIONS:

A. PARAMETER: AC Current @50Hz
Ratio of CT: 1000A/1A

Multiplier Factor Standard Input
A
(Through ZS/DMM/01)

Simulated High Current in
A Expected Secondary Current of CT As per the ratio
A Observed secondary Current of CT on Std. DMM A
(Through ZS/DMM/08)

Error A

% Error
10 1.001622 10.01622 10.01622 m 9.9930 m - 0.02322 - 0.23
20 1.000873 20.01746 20.01746 m 19.9532 m - 0.06426 - 0.32
30 1.000194 30.00582 30.00582 m 29.9480 m - 0.05782 - 0.19
40 1.000646 40.02584 40.02584 m 39.9242 m - 0.10164 - 0.25
50 1.000280 50.01400 50.01400 m 49.9125 m - 0.1015 - 0.20
60 0.999558 59.97348 59.97348 m 59.7923 m - 0.18118 - 0.30
70 1.000147 70.01029 70.01029 m 69.8638 m - 0.14649 - 0.21
80 1.000332 80.02656 80.02656 m 79.8245 m - 0.20206 - 0.25
90 1.000816 90.07344 90.07344 m 89.8437 m - 0.22974 - 0.26
100 1.000168 100.0168 100.0168 m 99.7418 m - 0.2750 - 0.27

Multiplier Factor Standard Input
A
(Through ZS/DMM/01)

Simulated High Current in
A Expected Secondary Current of CT As per the ratio
A Observed secondary Current of CT on Std. DMM A
(Through ZS/DMM/08)

Error A

% Error
10 5.00067 50.0067 50.0067 m 49.8767 m -0.1300 -0.26
20 5.00046 100.0092 100.0092 m 99.7780 m -0.2312 -0.23
30 5.00032 150.0096 150.0096 m 149.559 m -0.4506 -0.30
40 5.00097 200.0388 200.0388 m 199.443 m -0.5958 -0.30
50 5.00020 250.0100 250.0100 m 249.281 m -0.7290 -0.29
60 5.00054 300.0324 300.0324 m 299.155 m -0.8774 -0.29
70 5.00040 350.0280 350.0280 m 349.009 m -1.0190 -0.29
80 5.00078 400.0624 400.0624 m 398.810 m -1.2524 -0.31
90 5.00075 450.0675 0.4500675 0.448941 -0.001127 -0.25
100 5.00067 500.0670 0.5000670 0.498979 -0.001088 -0.22

Multiplier Factor Standard Input
A
(Through ZS/DMM/01)

Simulated High Current in
A Expected Secondary Current of CT As per the ratio
A Observed secondary Current of CT on Std. DMM A
(Through ZS/DMM/08)

Error A

% Error
10 9.99903 99.9903 0.0999903 0.099748 -0.000242 - 0.24
20 10.00224 200.0448 0.2000448 0.199673 -0.000372 - 0.19
30 10.00045 300.0135 0.3000135 0.299507 -0.000506 - 0.17
40 10.00141 400.0564 0.4000564 0.399330 -0.000726 - 0.18
50 10.00017 500.0085 0.5000085 0.499299 -0.000709 - 0.14
60 10.00545 600.327 0.600327 0.599456 -0.000871 - 0.15
70 10.00737 700.5159 0.7005159 0.699644 -0.000872 - 0.12
80 10.00138 800.1104 0.8001104 0.799170 -0.000940 - 0.12
90 10.00477 900.4293 0.9004293 0.899413 -0.001016 - 0.11
100 10.00783 1000.783 1.000783 0.999547 -0.001236 - 0.12

B. PARAMETER: DC Current

Multiplier Factor
Standard Input
A
(Through ZS/DMM/01)

Simulated High Current in
A
Observed Reading on Clamp on Meter
A (ZS/CLM/02)

Error A

% Error
10 1.001105 10.01105 10.2 0.18895 1.89
20 1.000708 20.01416 20.6 0.58584 2.93
30 1.000761 30.02283 30.8 0.77717 2.56
40 1.000017 40.00068 41.2 1.19932 3.00
50 0.999927 49.99635 51.5 1.50365 3.01
60 1.000733 60.04398 61.7 1.65602 2.76
70 1.000774 70.05418 71.9 1.84582 2.63
80 1.000717 80.05736 82.0 1.94264 2.43
90 1.000722 90.06498 92.3 2.23502 2.48
100 1.000769 100.0769 102.4 2.3231 2.32

Multiplier Factor Standard Input
A
(Through ZS/DMM/01)

Simulated High Current in
A Observed Reading on Clamp on Meter
A (ZS/CLM/02)

Error A

% Error
10 10.00045 100.0045 102.9 2.8955 2.90
20 10.00008 200.0016 206.0 5.9984 3.00
30 10.00108 300.0324 309.0 8.9676 2.99
40 10.00046 400.0184 411 10.9816 2.75
50 10.00247 500.1235 513 12.8765 2.57
60 10.00207 600.1242 614 13.8758 2.31
70 10.00170 700.119 715 14.8810 2.13
80 10.00156 800.1248 815 14.8752 1.86
90 10.00126 900.1134 916 15.8866 1.76
100 10.00095 1000.095 1017 16.9050 1.69

[0061] The system and method thereof for AC/DC current multiplier with amplifier based current source will serve as a stable and accurate high current simulator to calibrate both CTs and Clamps. The system and method thereof for AC/DC current multiplier with amplifier based current source will also be helpful for calibration and testing of Current transducers, Current sensors, Current transmitters or any other devices which act after sensing high current. The AC/DC current multiplier of the present invention needs source of relatively of lower wattage. Tremendous cost saving of electricity bills and space is achieved. Also, Reference CTs will not be required. The AC/DC current multiplier of the present invention reduces cost of multiple Reference CTs and saves their cost of maintaining calibration traceability every year from a prime lab. The AC/DC current multiplier of the present invention is small in size and less in weight, therefore it is easy to handle. The special tools and other accessories for making high current wiring are not required. Also, less heat dissipation will take place as cable losses due to flow of extremely high currents will be eliminated. The AC/DC current multiplier of the present invention meets calibration of CTs for ratio and phase errors and also takes care of calibration of AC & DC clamps.
[0062] Further, while one or more operations have been described as being performed by or otherwise related to certain modules, devices or entities, the operations may be performed by or otherwise related to any module, device or entity.
[0063] Further, the operations need not be performed in the disclosed order, although in some examples, an order may be preferred. Also, not all functions need to be performed to achieve the desired advantages of the disclosed system and method, and therefore not all functions are required.
[0064] While select examples of the disclosed system and method have been described, alterations and permutations of these examples will be apparent to those of ordinary skill in the art. Other changes, substitutions, and alterations are also possible without departing from the disclosed system and method in its broader aspects. , Claims:WE CLAIM:
1. A system for AC/DC current multiplier, the system comprises:
a plurality of connector having a plurality of pins (N) each, each connector having a plurality of pins (N) in the upperpart of the connector and equal number of pins (N) to that of the pins in the upperpart of the connector, in the lower part of the connector configured to make number of loops equal to one less than number of pins in the connector (N – 1), wherein the first loop begins from pin one of the upper part of the connector and ends at pin two of the lower part of the connector, the second loop begins from pin two of the upper part of the connector and ends pin three of the lower part of the connector and so on, making effectively number of loops equal to one less than number of pins in the connector (N – 1) per connector;
a plurality of flexible insulated copper wires to form loops, the number of flexible insulated copper wires forming loops being equal to one less than number of pins in the connector (N – 1) flexible insulated copper wires per connector constituting the system;
a make/break arrangement configured through connector ensuring firm connection of same pin numbers of upperpart and lower part when fit together;
feeding current to the pin one of the lower part of the first connector and taking return path of the current from the last pin of the lower part of the first connector constituting a current multiplier of X (one less than number of pins in the connector (N – 1));
replicating, the current multiplier of X(one less than number of pins in the connector (N – 1)) connection for required number of X(one less than number of pins in the connector (N – 1)) current multiplication and connecting last pin of a connector to first pin of the very next connector to connect all the loops from all the connector in series when all connectors are fitted;
a rotary switch comprising one pole and plurality of ways, the number of the plurality of ways being equal to the number of connectors constituting the system;
a junction point of a previous connector’s last pin and the first pin of the very next connector connected sequentially to one of the plurality of ways of the multi-way single pole rotary switch; and
a pole of the rotary switch connected to low potential point of a current source.

2. The system for AC/DC current multiplier as claimed in claim 1 wherein, the system comprises:
a plurality of connector having eleven pins each, each connector having eleven pins in the upperpart of the connector and eleven pins in the lower part of the connector configured to make ten loops wherein the first loop begins from pin one of the upper part of the connector and ends at pin two of the lower part of the connector, the second loop begins from pin two of the upper part of the connector and ends pin three of the lower part of the connector and so on, making effectively ten loops per connector;
a plurality of flexible insulated copper wires to form loops, the number of plurality of flexible insulated copper wires forming loops being equal to ten flexible insulated copper wires per connector constituting the system;
a make/break arrangement configured through connector ensuring firm connection of same pin numbers of upperpart and lower part when fit together;
feeding current to the pin one of the lower part of the first connector and taking return path of the current from the pin eleven of the lower part of the first connector constituting a current multiplier of X10;
replicating the current multiplier of X10 connection for required number of X10 current multiplication and connecting last pin of a connector to first pin of the very next connector to connect all the loops from all the connector in series when all connectors are fitted;
a rotary switch comprising one pole and plurality of ways, the number of the plurality of ways being equal to the number of connectors constituting the system;
a junction point of a previous connector’s last pin and the first pin of the very next connector connected sequentially to one of the plurality of ways of the multi-way single pole rotary switch; and
a pole of the rotary switch connected to low potential point of a current source.

3. The system as claimed in claim 1 or claim 2 wherein for calibrating CT, users have to loose the connector and fit it after insertion.

4. The system as claimed in claim 1 or claim 2 wherein each connector of plurality of pins (N) together with flexible insulated copper wires equal in number to one less than number of pins in the connector (N – 1) forming loops constitutes a current multiplier of X(one less than number of pins in the connector (N – 1)) with make/brake arrangement.

5. The system as claimed in claim 1 or claim 2 wherein reliable assembly of connector ensures firm connection of same pin numbers of upper part and lower part when fit together.

6. The system as claimed in claim 1or claim 2 wherein a low current source can be used for simulation of High current.

7. The system as claimed in claim 1 or claim 2 wherein current input to current multiplier can either be AC or DC.

8. The system as claimed in claim 1 or claim 2 wherein clamp meters having measurement range even beyond 1000A can be calibrated.

9. The system as claimed in claim 1 or claim 2 wherein the stability of the simulated high value Amp-Turns (AT) is same as that of the low -level input current.

10. The system as claimed in claim 1 or claim 2 wherein the current multiplier is configured to accommodate CT as well as clamps of different ratios and sizes for their calibration.

11. The system as claimed in claim 1 or claim 2 wherein the current multiplier is configured for multiple ranges of CT calibration by taping junction points of connector to connector and providing return path of current source through a rotary switch of a plurality of ways and one pole.

12. The system as claimed in claim 1 or claim 2 wherein need of master CT with very high current source is eliminated.

13. The system as claimed in claim 1 or claim 2 does not add any phase error to the simulated AT with respect to basic low current.

14. The system as claimed in claim 2 wherein each connector of plurality of pins together with flexible insulated copper wires equal in number to number of pins on connector -1 forming loops constitutes a current multiplier of X10 with make/brake arrangement.

15. The system as claimed in claim 2 wherein each connector of eleven pins together with ten flexible insulated copper wires forming ten loops constitutes a current multiplier of X10 with make/brake arrangement.

16. The system as claimed in claim 1 or claim 2 wherein the plurality of connector having a plurality of pins (N) each can be circular connector type, or rectangular connector type, or square connector type or connector made up of any other shape and type.
Dated this on 01st April, 2025

Prafulla Wange
(Agent for the applicant)
(IN/PA-2058)