FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS (AMENDMENT) RULES, 2006
COMPLETE SPECIFICATION
[See Section 10; rule 13]
“Current Carrying Capacity Management of a High Voltage Electrical Device”
Siemens Ltd., of Birla Aurora, Plot No. 1080, Dr Annie Besant Road, 400030 Worli, Mumbai, INDIA; and Siemens Energy Global GmbH & Co. KG, a German company, of Otto-Hahn-Ring 6, 81739 München, GERMANY,
The following specification particularly describes the invention and the manner in which it is to be performed:

Description
Current Carrying Capacity Management of a High Voltage Electrical Device
The present disclosure relates to high voltage electrical devices. More particularly, the present disclosure relates to high voltage switching devices such as earthing switches and disconnectors including a center-break disconnector, a double-side-break disconnector, a knee-type disconnector, a vertical break disconnector, a vertical reach disconnector, a side break disconnector, a pantograph disconnector, and/or a semi-pantograph disconnector. Furthermore, the present disclosure relates to a system and a method for managing operation of an electrical device based on a thermal model thereof.
A high voltage switching device, for example, a disconnector or an earthing switch is an essential part of any electrical power substation. A disconnector indicates a visible
isolating distance via an air-isolated gap. A disconnector is an assembly having a function of ensuring an interruption of voltage supply line with the switchgear when the disconnector is open, thus isolating the switchgear from electric supply. Such high voltage electrical devices are typically designed and manufactured for a specified nominal current also referred to as rated continuous current as per IEC 62271-102 edition 2 (2018) corresponding to a range of ambient temperatures that are also specified in advance. The suitability of the electrical device for these operating conditions, particularly the ambient temperature range, is verified in the context of type tests, temperature rise tests and/or continuous current tests. Such design, manufacturing and tests are carried out using the IEC 62271-1/102 standard.
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The standard IEC 62271 typically provides guidelines on how a high voltage electrical device must be operated. For example, the IEC 62271 standard validates a current carrying capacity of a distinct current path considering a defined maximum ambient temperature which is typically 40°C and 50°C respectively. The rated continuous current is set in such a way that at a current ambient temperature at the moment of the rated continuous current test, that is, the temperature rise test, an upper temperature limit for the electrical device is not exceeded, and the electrical device is not thermally overloaded. Thermal overload refers to a state in which at least part of the electrical device is heated up to an extent during operation that the temperature of this part exceeds the maximum permissible values. The maximum
permissible values can result from the material properties of the part and/or material combinations, for example, surface treatment, coating, etc., and are specified by the referred standards. For example, the IEC provides a table of precise temperature values for various materials such as Copper, Aluminium, Tin, Silver, etc., which must not be exceeded at the measuring point in order to judge the temperature rise test as passed or failed. These values are
deltas/differences, so that the temperature measurement unit of Kelvin can be used. Thus, it is easily visible, if the temperature rise at a certain measurement point on the electrical device is within the permitted limit at 40°C or 50°C. As a result of a thermal overload, the conductivity may decrease and lead to hot-spots, that is, increased
resistances, the insulation of the conductive components or other safety-related problems can fail, and therefore this state must be avoided during operation.
However, to avoid thermal overload also means that the high voltage device is not operated at its optimal current
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carrying capacity especially when the ambient temperatures go below 400C. Thus, there exists a need for efficient operation management of a high voltage electrical device that allows the device to operate at its maximum capacity while ensuring safe and standard compliant operation.
Accordingly, it is an object of the present disclosure, to provide a system and a method for managing operation, that is, current carrying capacity of an electrical device.
The present disclosure achieves the aforementioned object by providing a computer implemented method and a current carrying capacity management system that manage operation of an electrical device. As used herein, “electrical device” refers to a high voltage electrical device and particularly to a high voltage switching device such as a disconnector, an earthing switch, or a circuit breaker having a voltage rating greater than or equal to 35kV, a current carrying capacity of which is defined in IEC 62271 standard for a particular ambient temperature.
The computer implemented method disclosed herein obtains an ambient temperature associated with the electrical device. As used herein, “ambient temperature” refers to a temperature of the environment surrounding the current carrying path also referred to as the current carrying contact arms of the electrical device. According to one aspect of the present disclosure, the method obtains the ambient temperature from a temperature sensor mounted on the electrical device and in close proximity of the current carrying path for higher measurement accuracy. According to another aspect of the present disclosure, the method obtains the ambient
temperature from one or more sensors typically mounted on the electrical device that are capable of measuring the ambient
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temperature. According to yet another aspect of the present disclosure, the method obtains the ambient temperature from one or more external sources, for example, a meteorological department monitoring weather surrounding a substation in which the electrical device is physically located. According to yet another aspect of the present disclosure, the method obtains the ambient temperature from a combination of aforementioned sources and selects a highest temperature from the obtained ambient temperatures. Selection of the highest temperature ensures no thermal overloading of the electrical device upon increasing the current carrying capacity associated therewith.
According to another aspect of the present disclosure, the method obtains the ambient temperature at predefined
intervals, for example, every half an hour, every hour, twice a day, thrice a day, every week, every month, etc.
Advantageously, the predefined intervals are varied based on an existing season. For example, in summer the intervals at which the ambient temperatures are obtained may be less in the daytime because the chances of the ambient temperature dropping rapidly are much lower than in other seasons. According to another aspect of the present disclosure, the method obtains the ambient temperature continuously. Advantageously, the method stores the obtained ambient temperatures and corresponding time instances at which the ambient temperatures are obtained, for example, in a device management database.
The method dynamically determines a maximum current carrying capacity of the electrical device, during operation of the electrical device, based on the ambient temperature and supplier data associated with the electrical device, such that the electrical device when operated at the maximum
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current carrying capacity does not cause thermal overloading of the electrical device. As used herein, “supplier data” refers to data provided by the supplier or an original equipment manufacturer of the electrical device.
Advantageously, the supplier data comprises temperature rise test data associated with each temperature rise test performed on the electrical device, by the supplier. Advantageously, the method stores the supplier data for example, in the device management database.
Advantageously, the method determines the maximum current carrying capacity when a change observed in the ambient temperature is greater than or equal to a predefined threshold, for example 1°C. Cooler the ambient temperature higher is the current carrying capacity of the electrical device. Advantageously, the boundary conditions for the current carrying capacity include a lower limit of continuous current defined in the IEC 62271 standard at an ambient temperature of 40°C and 50°C respectively, and a higher limit of twice the continuous current defined at 40°C and 50°C respectively. The temperature rise test data comprises, for example, a rated continuous current applied to the electrical device while performing a temperature rise test, an ambient temperature at which the temperature rise test is performed, and a maximum temperature measured at a measurement point on the electrical device where a maximum temperature rise occurs while performing the temperature rise test. As used herein, “maximum temperature rise” refers to a temperature, measured at the measurement point on the electrical device, which is closest to the permitted temperature value as per the IEC standard. Moreover, the permitted value as per IEC standard is typically rated at 40°C and 50°C respectively. Therefore, this provides an indication on whether there exists room for increasing the current carrying capacity. For example, if the
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temperature rise in a test at a certain measurement point is 50K at an ambient temperature of 35°C and the IEC standard specifies a permissible temperature rise of 65K with ambient temperature 40°C then it is clear that the temperature rise will actually be 55K instead of 50K for ambient temperature of 40°C and about 65K for ambient temperature of 50°C. Thus, there exists room for increasing the rated continuous current, that is, the maximum current carrying capacity at the ambient temperature of 35°C without violating the permitted temperature rise of 65K at 40°C for an optimized current path usage.
According to another aspect of the present disclosure, the method determines the temperature rise test data in absence of supplier data based on supplier data provided by other suppliers for electrical devices having same rating and material of manufacture. For example, the method recommends a maximum temperature measured at a measurement point on the electrical device where a maximum temperature rise may have occurred while performing the temperature rise test and an operator of the electrical device may validate the recommendation based on his/her experience and/or visual inspection of the electrical device on site.
The method determines a temperature rise based on the maximum temperature measured at a measurement point on the electrical device where there occurs maximum temperature rise while performing the temperature rise test and a permissible temperature rise at the rated continuous current. The permissible temperature rise is specified in the IEC 62271 standard for a particular continuous current at a particular ambient temperature. The method determines the temperature rise, using the below formula:
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dTr = |Tmax - Tmaxperm|
Where dTr - temperature rise
Tmax - maximum temperature measured at a measurement point on the electrical device where the maximum temperature rise occurs while performing the temperature rise test and Tmaxperm - permissible temperature rise specified in the IEC 62271 at the rated continuous current Ir
The method determines the maximum current carrying capacity based on the rated continuous current, the temperature rise, the maximum temperature, and the permissible temperature rise. The method determines the maximum current carrying capacity also based on a potency factor which in turn is determined based on the supplier data. The method determines the maximum current carrying capacity, using the below formula:

Where T - current rise factor to be used for raising the existing current carrying capacity to the maximum current carrying capacity, and
v - potency factor determined by the method based on the temperature rise test data provided by suppliers of the electrical device. The potency factor defines a potency of the change in the current carrying capacity for a specific current path design of an electrical device. For example, higher the potency factor lesser is the change in the current carrying capacity compared to existing current carrying capacity of the current path. The potency factor is dependent
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on thermal radiation. According to one aspect of the present disclosure, the potency factor is defined by the supplier, that is, provided as the supplier data. The value of v typically ranges between about 1.4 to about 2. However, for worst-case scenario calculations, that is, to avoid thermal overloading of the electrical device, v is conservatively selected as 2. For example, if in the temperature rise test data provided by the suppliers, there exists data for one test conducted at one ambient temperature then the method selects v as 2 to be on safer side as per the IEC 62271-306 standard whereas, when there is data provided for at least two tests conducted at two different ambient temperatures at same rated continuous current, then the method selects a value lower than 2 up to about 1.4 or lower based on the IEC 62271-306 standard. Thus, the current rise factor T is calculated as square root of [(Tmax-Tamb)/dTr] when the potency factor v is 2.
The method determines a maximum permissible current Iamax that can be allowed to pass through the electrical device without causing thermal overloading of the electrical device as per the IEC 62271-306 standard, based on the rated continuous current at a particular ambient temperature, using the below formula:
Iamax = 2/r
That is, Iamax is the higher limit within which the current carrying capacity must be limited for safe operation of the electrical device. The method determines the maximum current carrying capacity, using the below formula:
la' = Ir*T
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Where Ia’ - the maximum current carrying capacity
According to one aspect of the present disclosure, the method compares the maximum current carrying capacity Ia’ with maximum permissible current Iamax. If Ia’ is less than or equal to Iamax then the method resets the existing current carrying capacity Ia at which the electrical device has been operating to Ia’, thereby increasing the current carrying capacity to an optimal level, that is:
la = la'
However, if Ia’ is greater than Iamax then the method initiates no action and the existing current carrying capacity Ia of the electrical device is maintained as is, that is:
la = la
Advantageously, considering the potency factor v while determining the maximum current carrying capacity (Ia’) enables to establish an indirect proportion between a temperature rise dT1 occurring at a first current carrying capacity I1 of an electrical device to a temperature rise dT2 occurring at a second current carrying capacity I2 with same potency v of the electrical device, that is, a same quotient value of v, represented as below:

Advantageously, the method stores each of the above computations into the device management database for purposes
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of future references, for example, applying learning on the
data to generate recommendations and operating plans for the
electrical device that optimize its current carrying capacity
at a particular geography in a particular climate.
Also, disclosed herein is a current carrying capacity management system for managing operation of an electrical device. The current carrying capacity management system comprises a non-transitory computer readable storage medium storing computer program instructions defined by modules of the current carrying capacity management system and at least one processor communicatively coupled to the non-transitory computer readable storage medium, wherein the at least one processor executes the computer program instructions. The modules of the current carrying capacity management system comprise, for example, a data reception module and a data processing module. The data reception module obtains an ambient temperature associated with the electrical device at predefined intervals from a temperature sensor mounted on the electrical device. The data reception module also receives the supplier data and the IEC 62271 standard data. The data reception module obtains the temperature rise test data comprising a rated continuous current applied to the electrical device while performing a temperature rise test, an ambient temperature at which the temperature rise test is performed, and/or a maximum temperature measured at a measurement point on the electrical device where there is maximum temperature rise while performing the temperature rise test.
The data processing module dynamically determines a maximum current carrying capacity of the electrical device, during operation of the electrical device based on the ambient temperature and supplier data associated with the electrical
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device, such that the electrical device when operated at the maximum current carrying capacity does not cause thermal overloading of the electrical device, wherein the supplier data comprises temperature rise test data associated with each temperature rise test performed on the electrical device.
The data processing module determines a temperature rise based on the maximum temperature measured at a measurement point on the electrical device where a maximum temperature rise occurs while performing the temperature rise test, and a permissible temperature rise at a rated continuous current of the temperature rise test data. The current carrying capacity management system determines the maximum current carrying capacity based on the rated continuous current, the temperature rise, the maximum temperature, and the permissible temperature rise.
Also disclosed herein, is a computer program product comprising a non-transitory computer readable storage medium storing computer program codes that comprise instructions executable by at least one processor. The computer program codes multiple computer program codes for executing steps carried out by the aforementioned computer implemented method disclosed herein.
The computer implemented method, the current carrying capacity management system and the computer program product disclosed herein allow a safe and clear indication of a continuous current at a particular ambient temperature for optimally increasing an existing current carrying capacity of an electrical device thereby, allowing higher current and therefore, power to be transmitted therethrough, especially
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during cooler ambient temperatures, leading to increased economic benefits.
The above mentioned and other features of the invention will now be addressed with reference to the accompanying drawings of the present invention. The illustrated embodiments are intended to illustrate, but not limit the invention.
The present invention is further described hereinafter with reference to illustrated embodiments shown in the accompanying drawings, in which:
FIG 1 is a perspective view of an active part of a
switching device such as a horizontal center-break type disconnector according to an embodiment of the present disclosure.
FIG 2 illustrates a process flowchart of a computer-
implemented method for managing operation of an electrical device shown in FIG 1, according to an embodiment of the present disclosure.
FIG 3 illustrates a current carrying capacity
management system for managing operation of an electrical device shown in FIG 1, according to an embodiment of the present disclosure.
FIG 4 is a block diagram illustrating an
architecture of a computer system employed by the current carrying capacity management system shown in FIG 3, for managing operation of an electrical device shown in FIG 1, according to an embodiment of the present disclosure.
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FIG 5 illustrates an exemplary graphical
representation of the current carrying capacity determined for various ambient temperatures surrounding an electrical device shown in FIG 1, using the method disclosed in the detailed description of FIG 2, according to an embodiment of the present disclosure.
Various embodiments are described with reference to the drawings, wherein like reference numerals are used to refer like elements throughout. In the following description, for the purpose of explanation, numerous specific details are set forth in order to provide thorough understanding of one or more embodiments. It may be evident that such embodiments may be practiced without these specific details.
FIG 1 is a perspective view of an active part of a high voltage switching device, for example, a horizontal center-break type disconnector 100 according to an embodiment of the present disclosure. The switching device 100 has movable current path arms 101A and 101B detachably coupled to each other and capable of rotation to occupy two positions, namely a closed position and an open position. The configuration shown in FIG 1A represents the closed position wherein the moveable current path arms 101A and 101B are in electrical contact with each other via a main contact system 103. In the open position, the moveable current path arms 101A and 101B rotate so as to break the electrical contact between them. Each of the moveable current path arms 101A and 101B are connected to the electricity supply and to the distribution bus bars via transfer contact systems 102C and 102D having rotatable terminal stems 102A and 102B respectively. Each of the terminal stems 102A and 102B, the moveable current path
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arms 101A and 101B, and the main contact system 103, are supported by insulators 104A and 104B which are in turn supported by a base frame 106. The base frame 106 comprises rotary units 105A and 105B that incorporate a rotation drive mechanism providing linear and/or rotary movement to the insulators 104A and 104B and the contact system 103 thereby, leading to making and breaking of the current path between the moveable current path arms 101A and 101B. The rotary units 105A and 105B typically comprise ball-bearings, shaft, disc, etc., designed for handling high mechanical loads.
One or more temperature sensors 107 are mounted on the base frame 106 for measuring the ambient temperature. The temperature sensor 107 wirelessly transmits the measured ambient temperature, for example to a computer device (not shown).
FIG 2 illustrates a process flowchart of a computer-implemented method 200 for managing operation of an electrical device 100 shown in FIG 1, according to an embodiment of the present disclosure. The method at step 201, obtains an ambient temperature Tamb associated with the electrical device 100, from the temperature sensor 107.
At step 201A, the method obtains the ambient temperature Tamb as per predefined intervals, such as, every hour, every two hours, every day, etc. Alternatively, at step 201A, the method continuously obtains and monitors the ambient temperature Tamb. At step 201B, the method compares the obtained ambient temperature Tamb with the previous ambient temperature at which the electrical device 100 was operating and whether the difference between the two temperatures is greater than or equal to a predefined threshold, for example, 1°C. If not, then the method goes back to step 201A for
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obtaining and/or monitoring the ambient temperature. Else, if yes, that is if the difference between the two temperatures is greater than or equal to 1°C then, at step 201C, the method receives the supplier data stored in a device management database. The supplier data includes temperature rise test data associated with each temperature rise test performed on the electrical device 100. The temperature rise test data comprises, for example, a rated continuous current Ir applied to the electrical device 100 while performing a temperature rise test, an ambient temperature Tambtest at which the temperature rise test is performed, and/or a maximum temperature Tmax measured at a measurement point (not shown) on the electrical device 100 where there is maximum temperature rise while performing the temperature rise test.
At step 201D, the method receives IEC 62271 standard data stored in the device management database. The IEC 62271 standard data comprises a maximum permissible current Iamax to be carried by the electrical device 100 at a particular ambient temperature Tamb and a permissible temperature rise Tmaxperm of the current path arms 101A and 101B of the electrical device 100 when carrying the rated continuous current Ir therethrough.
The method at step 202, dynamically determines a maximum current carrying capacity Ia’ of the electrical device 100, during operation of the electrical device 100, based on the ambient temperature Tamb and the supplier data associated with the electrical device 100, such that the electrical device 100 when operated at the maximum current carrying capacity Ia’ does not cause thermal overloading of the electrical device 100.
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At step 202A, the method determines a maximum permissible current Iamax that can be allowed to pass through the electrical device 100 as per the IEC 62271 standard, based on the rated continuous current Ir at a particular ambient temperature Tamb, using the below formula:
����� = 2��
At step 202B, the method determines a temperature rise dTr based on the maximum temperature Tmax measured at a measurement point on the electrical device 100 where there is maximum temperature rise while performing the temperature rise test and a permissible temperature rise Tmaxperm at the rated continuous current Ir, using the below formula:
dTr = |Tmax - Tmaxperm|
At step 202C, the method calculates a current rise factor Ʈ to be used for raising the existing current carrying capacity to maximum current carrying capacity Ia’ without causing thermal overloading of the electrical device 100, using the below formula:

Wherein v is potency factor provided by suppliers of the electrical device 100 and is dependent on thermal radiation. The value of V typically ranges between about 1.4 to about 2. However, for worst-case scenario calculations, that is, to avoid thermal overloading of the electrical device 100 v is selected as 2. Thus, the current rise factor Ʈ is calculated as square root of [(Tmax-Tamb)/dTr].
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At step 202D, the method determines the maximum current carrying capacity Ia’ using the below formula:
la' = Ir*T
At step 202E. the method compares the maximum current carrying capacity Ia’ with maximum permissible current Iamax that can be allowed to pass through the electrical device 100 as per the IEC 62271 standard. If Ia’ is less than or equal to Iamax then the existing current carrying capacity Ia at which the electrical device 100 is operating is reset to Ia’, that is:
la = la'
However, if Ia’ is greater than Iamax then at step 202G, no action is triggered and the existing current carrying capacity Ia of the electrical device 100 is maintained as is, and the method reverts to step 201A, that is:
la = la
Consider an example, where a high voltage horizontal center break (HCB) disconnector having a rating of 245kV, 40kA, 50Hz with a rated continuous current Ir of 2500A is being managed for optimizing its current carrying capacity. Assume that the HCB disconnector is operating at a current carrying capacity equal to the rated continuous current of 2500A and at an ambient temperature Tamb of 350C. The method 200 monitors changes in the ambient temperature where the Tamb drops to 330C which is higher than the predefined threshold of 1°C. In this case, the method 200 receives the supplier data and the
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IEC 62271 standard data associated with the HCB disconnector as below:
1. Potency V = 2
2. Maximum temperature measured at a measurement point on the HCB disconnector where there occurred maximum temperature rise while performing the temperature rise test
Tmax = 88.50C
3. Maximum permissible temperature rise Tmaxperm at the
rated continuous current Ir
Tmaxperm = 350C
Based on above values, the method 200 determines:
1. Iamax as 2*Ir = 5000A
2. dTr = Tmax - Tmaxperm = 53.50C
3. Ʈ = root square [(Tmax-Tamb)/dTr] = √ [(88.5-33)/53.5] = 1.018
4. Ia’ = Ir*Ʈ = 2500*1.018 = 2545A
The method 200 verifies whether Ia’ is less than or equal to Iamax and sets the current carrying capacity of the HCB disconnector to 2545A until the ambient temperature remains to be 330C +/- 0.9.
The method 200 keeps monitoring the changes occurring in the ambient temperature Tamb and dynamically calculates the optimal current carrying capacity suitable for the changed ambient temperature. This optimal current carrying capacity is then used for operating the HCB disconnector.
FIG 3 illustrates a current carrying capacity management system 300 for managing operation of an electrical device 100
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shown in FIG 1, according to an embodiment of the present disclosure. The current carrying capacity management system 300, is installable on and accessible by a user device, for example, a personal computing device, a workstation, a client device, a network enabled computing device, any other suitable computing equipment, and combinations of multiple pieces of computing equipment. The current carrying capacity management system 300 disclosed herein is in operable communication with a device management database 303 over a communication network 304. The communication network 304 is, for example, a wired network, a wireless network, or a network formed from any combination thereof. The current carrying capacity management system 300 disclosed herein is in operable communication with the temperature sensor 107 mounted on the electrical device 100 over the communication network 304.
The current carrying capacity management system 300 is downloadable and usable on the user device, or, is configured as a web-based platform, for example, a website hosted on a server or a network of servers, or, is implemented in the cloud computing environment as a cloud computing-based platform implemented as a service for recommending an optimal current carrying capacity for various electrical devices 100. A user of the current carrying capacity management system 300 is typically an operator at a substation, responsible for managing operation of electrical devices 100 deployed in the substation.
The current carrying capacity management system 300 disclosed herein comprises a non-transitory computer readable storage medium and at least one processor communicatively coupled to the non-transitory computer readable storage medium. As used herein, “non-transitory computer readable storage medium”
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refers to all computer readable media, for example, non-volatile media, volatile media, and transmission media except for a transitory, propagating signal. The non-transitory computer readable storage medium is configured to store computer program instructions defined by modules, for example, 301, 302, etc., of the current carrying capacity management system 300. The processor is configured to execute the defined computer program instructions. As illustrated in FIG 3, the current carrying capacity management system 300 comprises a graphical user interface (GUI) 305. A user using the user device can access the current carrying capacity management system 300 via the GUI 305. The GUI 305 is, for example, an online web interface, a web based downloadable application interface, etc. The current carrying capacity management system 300 further comprises a data reception module 301 and a data processing module 302.
The data reception module 301 obtains an ambient temperature Tamb associated with the electrical device 100 at predefined intervals from the temperature sensor 107 mounted on the electrical device 100. The data reception module 301 also accesses data such as the supplier data including the temperature rise test data, and the IEC 62271 standard data associated with the electrical device 100 from the device management database 303. The temperature rise test data comprises a rated continuous current Ir applied to the electrical device 100 while performing a temperature rise test, an ambient temperature Tambtest at which the temperature rise test is performed, and/or a maximum temperature Tmax measured at a measurement point on the electrical device 100 where there is maximum temperature rise while performing the temperature rise test.
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The data processing module 302 dynamically determines a maximum current carrying capacity Ia’ of the electrical device 100, during operation of the electrical device 100 based on the ambient temperature Tamb and the supplier data associated with the electrical device 100, such that the electrical device 100 when operated at the maximum current carrying capacity Ia’ does not cause thermal overloading of the electrical device 100. The data processing module 302 determines a temperature rise dTr based on the maximum temperature Tmax measured at a measurement point on the electrical device 100 where maximum temperature rise occurs while performing the temperature rise test and a permissible temperature rise Tmaxperm at a rated continuous current Ir of the temperature rise test data. The data processing module 302 determines the maximum current carrying capacity Ia’ based on the rated continuous current Ir, the temperature rise dTr, the maximum temperature Tmax, and the permissible temperature rise Tmaxperm.
FIG 4 is a block diagram illustrating architecture of a computer system 400 employed by the current carrying capacity management system 300 illustrated in FIG 3, for managing operation of the electrical device 100. The current carrying capacity management system 300 employs the architecture of the computer system 400. The computer system 400 is programmable using a high-level computer programming language. The computer system 400 may be implemented using programmed and purposeful hardware. As illustrated in FIG 4, the computer system 400 comprises a processor 401, a non-transitory computer readable storage medium such as a memory unit 402 for storing programs and data, an input/output (I/O) controller 403, a network interface 404, a data bus 405, a display unit 406, input devices 407, a fixed media drive 408 such as a hard drive, a removable media drive 409 for
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receiving removable media, output devices 410, etc. The processor 401 refers to any one of microprocessors, central processing unit (CPU) devices, finite state machines, microcontrollers, digital signal processors, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc., or any combination thereof, capable of executing computer programs or a series of commands, instructions, or state transitions. The processor 401 may also be implemented as a processor set comprising, for example, a general-purpose microprocessor and a math or graphics co-processor. The current carrying capacity management system 300 disclosed herein is not limited to a computer system 400 employing a processor 401. The computer system 400 may also employ a controller or a microcontroller. The processor 401 executes the modules, for example, 301, 302, etc., of the current carrying capacity management system 300.
The memory unit 402 is used for storing programs,
applications, and data. For example, the modules 301, 302, etc., of the current carrying capacity management system 300 are stored in the memory unit 402 of the computer system 400. The memory unit 402 is, for example, a random-access memory (RAM) or another type of dynamic storage device that stores information and instructions for execution by the processor 401. The memory unit 402 also stores temporary variables and other intermediate information used during execution of the instructions by the processor 401. The computer system 400 further comprises a read only memory (ROM) or another type of static storage device that stores static information and instructions for the processor 401. The I/O controller 403 controls input actions and output actions performed by the current carrying capacity management system 300.
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The network interface 404 enables connection of the computer system 400 to the communication network 304. For example, the current carrying capacity management system 300 connects to the communication network 304 via the network interface 404. In an embodiment, the network interface 404 is provided as an interface card also referred to as a line card. The network interface 404 comprises, for example, interfaces using serial protocols, interfaces using parallel protocols, and Ethernet communication interfaces, interfaces based on wireless communications technology such as satellite technology, radio frequency (RF) technology, near field communication, etc. The data bus 405 permits communications between the modules, for example, 301, 302, 303, 305, etc., of current carrying capacity management system 300.
The display unit 406, via the graphical user interface (GUI) 305, displays information such as the maximum current carrying capacity Ia’ determined for a particular ambient temperature Tamb, user interface elements such as text fields, buttons, windows, etc., for allowing a user to provide his/her inputs such as device installation data. The display unit 406 comprises, for example, a liquid crystal display, a plasma display, an organic light emitting diode (OLED) based display, etc. The input devices 407 are used for inputting data into the computer system 400. The input devices 407 are, for example, a keyboard such as an alphanumeric keyboard, a touch sensitive display device, and/or any device capable of sensing a tactile input.
Computer applications and programs are used for operating the computer system 400. The programs are loaded onto the fixed media drive 408 and into the memory unit 402 of the computer system 400 via the removable media drive 409. In an embodiment, the computer applications and programs may be
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loaded directly via the communication network 304. Computer applications and programs are executed by double clicking a related icon displayed on the display unit 406 using one of the input devices 407. The output devices 410 output the results of operations performed by the current carrying capacity management system 300. For example, the current carrying capacity management system 300 provides graphical representation of the recommendations, that is, the maximum current carrying capacity Ia’ determined, using the output devices 410. Alternatively, the graphical representations may include statistics and analytics of the historical operational data associated with the electrical device 100 such as different ambient temperatures that occurred over a certain time duration and the associated current at which the electrical device 100 was operated at.
The processor 401 executes an operating system. The computer system 400 employs the operating system for performing multiple tasks. The operating system is responsible for management and coordination of activities and sharing of resources of the computer system 400. The operating system further manages security of the computer system 400, peripheral devices connected to the computer system 400, and network connections. The operating system employed on the computer system 400 recognizes, for example, inputs provided by the users using one of the input devices 407, the output display, files, and directories stored locally on the fixed media drive 408. The operating system on the computer system 400 executes different programs using the processor 401. The processor 401 and the operating system together define a computer platform for which application programs in high level programming languages are written.
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The processor 401 of the computer system 400 employed by the current carrying capacity management system 300 retrieves instructions defined by the modules 301, 302, etc., of the current carrying capacity management system 300 for performing respective functions disclosed in the detailed description of FIG 3. The processor 401 retrieves instructions for executing the modules, for example, 301,
302, etc., of the current carrying capacity management system
300 from the memory unit 402. A program counter determines
the location of the instructions in the memory unit 402. The
program counter stores a number that identifies the current
position in the program of each of the modules, for example,
301, 302, etc., of the current carrying capacity management
system 300. The instructions fetched by the processor 401
from the memory unit 402 after being processed are decoded.
The instructions are stored in an instruction register in the
processor 401. After processing and decoding, the processor
401 executes the instructions, thereby performing one or more
processes defined by those instructions.
At the time of execution, the instructions stored in the instruction register are examined to determine the operations to be performed. The processor 401 then performs the specified operations. The operations comprise arithmetic operations and logic operations. The operating system performs multiple routines for performing several tasks required to assign the input devices 407, the output devices 410, and memory for execution of the modules, for example,
303, 304, etc., of the current carrying capacity management
system 300. The tasks performed by the operating system
comprise, for example, assigning memory to the modules, for
example, 301, 302, etc., of the current carrying capacity
management system 300, and to data used by the current
carrying capacity management system 300, moving data between
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the memory unit 402 and disk units, and handling input/output operations. The operating system performs the tasks on request by the operations and after performing the tasks, the operating system transfers the execution control back to the processor 401. The processor 401 continues the execution to obtain one or more outputs. The outputs of the execution of the modules, for example, 301, 302, etc., of the current carrying capacity management system 300 are displayed to the user on the GUI 305.
For purposes of illustration, the detailed description refers to the current carrying capacity management system 300 being run locally on the computer system 400, however the scope of the present invention is not limited to the current carrying capacity management system 300 being run locally on the computer system 400 via the operating system and the processor 401, but may be extended to run remotely over the communication network 304 by employing a web browser and a remote server, a mobile phone, or other electronic devices. One or more portions of the computer system 400 may be distributed across one or more computer systems (not shown) coupled to the communication network 304.
Disclosed herein is also a computer program product
comprising a non-transitory computer readable storage medium that stores computer program codes comprising instructions executable by at least one processor 401 for managing operation of an electrical device 100, as disclosed in aforementioned description. The computer program product comprises a first computer program code for obtaining an ambient temperature Tamb associated with the electrical device 100; a second computer program code for dynamically determining a maximum current carrying capacity Ia’ of the electrical device 100, during operation of the electrical
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device 100, based on the ambient temperature Tamb and
supplier data associated with the electrical device 100, such
that the electrical device 100 when operated at the maximum
current carrying capacity Ia’ does not cause thermal
overloading of the electrical device 100.
In an embodiment, a single piece of computer program code comprising computer executable instructions performs one or more steps of the method according to the present disclosure, for managing operation of an electrical device. The computer program codes comprising computer executable instructions are embodied on the non-transitory computer readable storage medium. The processor 401 of the computer system 400
retrieves these computer executable instructions and executes them. When the computer executable instructions are executed by the processor 401, the computer executable instructions cause the processor 401 to perform the steps of the method for managing operation of an electrical device.
FIG 5 illustrates an exemplary graphical representation 500 of the current carrying capacity Ia’ determined for various ambient temperatures Tamb surrounding an electrical device 100 shown in FIG 1, using the method 200 disclosed in the detailed description of FIG 2, according to an embodiment of the present disclosure. The graphical representation 500 illustrates on its X axis various possible ambient temperatures Tamb in °C and on its Y axis the dynamically calculated current carrying capacity, also referred to as, continuous current that can be safely carried by the electrical device 100 at the corresponding ambient
temperature Tamb. The electrical device 100 is a horizontal center break disconnector having a rating of 245kV, 40kA 50Hz. As seen from the graphical representation 500, along with variation in ambient temperatures Tamb, the potency
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factor v is also varied between 1.4 and 2. It can be observed from the graphical representation 500 that the potency factor of 2 provides safest current carrying capacity Ia’, that is, a continuous current closest to that recommended as be the IEC 62271 standard for respective ambient temperature Tamb.
While the present invention has been described in detail with reference to certain embodiments, it should be appreciated that the present invention is not limited to those embodiments. In view of the present disclosure, many modifications and variations would be present themselves, to those skilled in the art without departing from the scope of the various embodiments of the present invention, as described herein. The scope of the present invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.

List of Reference Numerals
100 switching device/disconnector/high voltage electrical device/electrical device
101A, 101B movable current path arms
102A, 102B terminal stems
103 contact system
104A, 104B insulators
105A, 105B rotary units/rotary bases/rotary stool bases/rotary pedestals
106 base frame
107 temperature sensor

300 current carrying capacity management system
301 data reception module
302 data processing module
303 device management database
304 communication network
305 Graphical user interface (GUI)

401 processor
402 memory unit
403 input/output (I/O) controller
404 network interface
405 data bus
406 display unit
407 input devices
408 fixed media drive
409 removable media drive
410 output devices
500 graphical representation of the current carrying capacity determined for various
ambient temperatures surrounding an electrical device

Patent claims:
1. A computer implemented method (200) for managing operation
of an electrical device (100), characterized by:
- obtaining (201) an ambient temperature (Tamb) associated with the electrical device (100); and
- dynamically determining (202) a maximum current carrying capacity (Ia’) of the electrical device (100), during operation of the electrical device (100), based on the ambient temperature (Tamb) and supplier data associated with the electrical device (100), such that the electrical device (100) when operated at the maximum current carrying capacity (Ia’) does not cause thermal overloading of the electrical device (100).

2. The computer implemented method (200) according to claim 1, wherein the ambient temperature (Tamb) is obtained at predefined intervals.
3. The computer implemented method (200) according to any one of the claims 1 and 2, wherein the ambient temperature (Tamb) is obtained from a temperature sensor (107) mounted on the electrical device (100).
4. The computer implemented method (200) according to claim 1, wherein the supplier data comprises temperature rise test data associated with each temperature rise test performed on the electrical device (100).
5. The computer implemented method (200) according to claim 4, wherein the temperature rise test data comprises one or more of a rated continuous current (Ir) applied to the electrical device (100) while performing a temperature
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rise test, an ambient temperature (Tambtest) at which the temperature rise test is performed, and a maximum temperature (Tmax) measured at a measurement point on the electrical device (100) where there is maximum temperature rise while performing the temperature rise test.
6. The computer implemented method (200) according to claim
5, further comprising determining a temperature rise (dTr)
based on the maximum temperature (Tmax) measured at a
measurement point on the electrical device (100) where
there is maximum temperature rise while performing the
temperature rise test and a permissible temperature rise
(Tmaxperm) at the rated continuous current (Ir).
7. The computer implemented method (200) according to claim
6, wherein the maximum current carrying capacity (Ia’) is
determined based on the rated continuous current (Ir), the
temperature rise (dTr), the maximum temperature (Tmax),
and the permissible temperature rise (Tmaxperm).
8. The computer implemented method (200) according to claim
7, wherein the maximum current carrying capacity (Ia’) is
determined based on a potency factor (v), and wherein the
potency factor (v) is determined based on the supplier
data.
9. The computer implemented method (200) according to claim
1, wherein the electrical device (100) is a high voltage
electrical device.
10. A current carrying capacity management system (300) for
managing operation of an electrical device (100), said
current carrying capacity management system (300)
comprising:
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- a non-transitory computer readable storage medium storing computer program instructions defined by modules of the current carrying capacity management system (300);
- at least one processor (401) communicatively coupled to the non-transitory computer readable storage medium, wherein the at least one processor (401) executes the computer program instructions; and
- the modules of the current carrying capacity management system (300) comprising:
o a data reception module (301) configured to obtain an ambient temperature (Tamb) associated with the electrical device (100) at predefined intervals from a temperature sensor (107) mounted on the electrical device (100); and
o a data processing module (302) configured to
dynamically determine a maximum current carrying capacity (Ia’) of the electrical device (100), during operation of the electrical device (100) based on the ambient temperature (Tamb) and supplier data associated with the electrical device (100), such that the electrical device (100) when operated at the maximum current carrying capacity (Ia’) does not cause thermal overloading of the electrical device (100), wherein the supplier data comprises temperature rise test data associated with each temperature rise test performed on the electrical device (100).
11. The current carrying capacity management system (300) according to claim 10, wherein the data reception module (301) obtains the temperature rise test data comprising
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one or more of a rated continuous current (Ir) applied to the electrical device (100) while performing a temperature rise test, an ambient temperature (Tambtest) at which the temperature rise test is performed, and a maximum temperature (Tmax) measured at a measurement point on the electrical device (100) where there is maximum temperature rise while performing the temperature rise test.
12. The current carrying capacity management system (300) according to claim 10, wherein the data processing module (302) determines a temperature rise (dTr) based on the maximum temperature (Tmax) measured at a measurement point on the electrical device (100) where there is maximum temperature rise while performing the temperature rise test and a permissible temperature rise (Tmaxperm) at a rated continuous current (Ir) of the temperature rise test data.
13. The current carrying capacity management system (300) according to claim 12, wherein the data processing module (302) determines the maximum current carrying capacity (Ia’) based on the rated continuous current (Ir), the temperature rise (dTr), the maximum temperature (Tmax), and the permissible temperature rise (Tmaxperm).
14. The current carrying capacity management system (300) according to claim 13, wherein the data processing module (302) determines the maximum current carrying capacity (Ia’) based on a potency factor (v), and wherein the potency factor (v) is determined based on the supplier data.
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15. The current carrying capacity management system (300)
according to claim 10, wherein the electrical device (100) is a high voltage electrical device.