Generating a charging profile for charging an energy storage device

Abstract

Examples for charging an energy storage device of an electric vehicle based on a charging profile, are described. In an example, initially, a plurality of charging attributes of the energy storage device is obtained. Thereafter, charging characteristics of the energy storage device are extracted from a data repository. Then, a charging time function indicating linear relation between total time to charge with a plurality of charging time is subjected to be optimized with respect to a plurality of charging attribute constraints to determine a charging profile. Once generated, the charging profile is transmitted to a power supply source to enable charging of the energy storage device.

Description

GENERATING A CHARGING PROFILE FOR CHARGING AN ENERGY STORAGE DEVICEBACKGROUND

[0001] Electronic devices, such as smart phones, laptops, PC’s, and other electrically powered systems, such as electric vehicles, may use an energy storage device, such as a rechargeable battery for powering. The energy storage device provides electrical energy to power different components of such devices or systems. Once discharged, the electronic system needs to be connected to a power supply source for recharging the energy storage device up to a certain state of charge (SoC). The energy storage device of the electronic devices may be charged by providing appropriate charging current.BRIEF DESCRIPTION OF DRAWINGS

[0002] The detailed description is provided with reference to the accompanying figures, wherein:

[0003] FIG. 1 illustrates an exemplary charging environment depicting a vehicle connected to a power supply source for charging an energy storage device, in accordance with one implementation of the present subject matter;

[0004] FIG. 2 illustrates a block diagram of a control unit, in accordance with one implementation of the present subject matter; and

[0005] FIG. 3 illustrates an exemplary method for charging an energy storage device based on a charging profile, in accordance with one implementation of the present subject matter.

[0006] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and / or implementations consistent with the description; however,the description is not limited to the examples and / or implementations provided in the drawings.DETAILED DESCRIPTION

[0007] Different components of electronic or mechanical devices, e.g., electric motor in an electric vehicle, operate on electric energy which may be provided by an energy storage device, such as a rechargeable battery. Such components draw power from the energy storage device to function appropriately. With passage of time as the device is used, the energy storage device may get discharged. Once discharged, due to it rechargeable capacities, the energy storage device may be recharged by connecting it to a power supply source. With increasing demand of device which are powered through electrical source of energy, specifically, electric vehicles, quick charging times for charging the energy storage device has become an essential requirement.

[0008] Generally, electric vehicles need several hours of time for recharging their energy storage devices. Such long hours of time results in downside usage of EVs by the users. There are several fast-charging methods available in the market which may effectuate quick charging of energy storage devices. However, existing fast-charging methods either fail to provide better energy storage device health or efficient charging to provide an improved used experience. For example, on one hand, some charging methods provide quick charging facility by opting for higher c- rates, but these compromise the health and longevity of the energy storage device due to the overloading of current. On the other hand, some charging methods follow a linear charging rate (i.e., constant rate), which while ensuring battery longevity, fails to provide the quickest possible charging time. Therefore, there is a need to provide such an approach which may ensure battery health as well as efficient charging to provide an improved user experience.

[0009] Examples for charging an energy storage device of an electric vehicle based on a charging profile, are described. In an example, a charging profile provides information to the electrically powered system about a charging parameter, such as c-rate and corresponding charging time for that c-rate. In operation, when the energy storage device is plugged in or connected with a power supply source for charging, the electric vehicle obtains a plurality of charging attributes of the energy storage device. In an example, the plurality of charging attributes includes a current state of charge (SoC), a current temperature, and a target SoC of the energy storage device. For example, on connecting the energy storage device to the power supply source, the electric vehicle obtains charging attributes, such as current SoC and current temperature, from the energy storage device itself. Further, the other charging attributes, such as target SoC may be obtained by electric vehicle either via a user based on its requirement or it may take target SoC as 100% by default.

[0010] Once obtained, the electrically powered system extracts charging characteristics of the energy storage device from a data repository. In an example, the charging characteristics includes change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates for the energy storage device. The charging characteristics are stored in the data repository based on previously conducted charging operations on the energy storage device. For example, based on charging operations conducted by plurality of battery manufacturers on plurality of energy storage devices, corresponding charging characteristics are stored in the data repository to be used as standard characteristics for performing future charging operation.

[0011] Thereafter, the electric vehicle generates a charging time function corresponding to a charging operation. In an example, the charging time function indicates a linear relation between total time to charge (TTC) for the energy storage device with a plurality of charging time corresponding to the plurality of charging rates. Once generated, the electric vehicleoptimizes the charging time function with respect to a plurality of charging attributes constraints to determine a charging profile. In an example, while optimizing the charging time function, the electric vehicle applies plurality of charging attributes and charging characteristics of the energy storage device as limiting values to minimize the charging time function to determine the charging profile with minimized TTC for energy storage device. In an example, the charging profile includes a set of values of a charging parameter. Examples of charging parameters include, but are not limited to, c-rate for charging and charging time for corresponding c-rate. In an example,

[0012] Returning to the present example, once determined, the charging profile is transmitted to the power supply source to be used as a standard profile to provide charging current to the energy storage device for charging. In an example, the electric vehicle generates a charging signal including the charging profile which is to be transmitted to the power supply source connected to the energy storage device. In response, the power supply source provides a charging current based on the charging profile included in the charging signal for charging the energy storage device.

[0013] The present approaches allow determining the charging profile for charging the energy storage device by optimizing the charging time function with respect to the plurality of charging attributes constraints based on charging attributes and charging characteristics of the energy storage device. For optimizing the charging time function, the electric vehicle may use any Linear programming problem solving techniques, such as dual simplex method or graph theory method, to minimize the charging time function. Therefore, the main objective of the present subject matter is to minimize the time to charge while achieving the required target SoC and keeping the temperature of the energy storage device under the desired threshold.

[0014] It may be noted that, although the present subject matter either above or in conjunction with drawings is described in context of an energystorage device comprised in an electric vehicle, the same should not be construed as a limitation. In another example, the present subject matter may be used for determining charging profile of energy storage device installed in any other electronic device without deviating from the scope of the present subject matter.

[0015] The manner in which the electric vehicle including a control unit determines the charging profile of the energy storage device is explained in detail with respect to FIG. 1 -3. While aspects of described control unit may be implemented in any number of different electronic devices, environments, and / or implementation, the examples are described in the context of the following example device(s). It may be noted that drawings of the present subject matter shown here are for illustrative purposes and are not to be construed as limiting the scope of the subject matter claimed.

[0016] FIG. 1 illustrates a charging environment 100 depicting an electric vehicle 102 connected to a power supply source 104 for charging an energy storage device 106 via charging cable (as depicted in FIG. 1 ). In an example, the energy storage device 106 is used as an electrical energy source to power different component of the electric vehicle 102. Examples of such electric vehicle 102 include, but may not be limited to, electric twowheeler, electric car, electric bus, etc. Although, the electric vehicle 102 in FIG. 1 is depicted as connected to the power supply source 104 (referred to as the power source 104) at the back end of the electric vehicle, however, the same may should not be construed as limitation. Further, although, the description is provided with respect to the electric vehicle 102 (hereinafter referred to as vehicle 102) including the energy storage device 106, the same may also be implemented for any electronic device comprising the energy storage device without deviating from the scope of the present subject matter.

[0017] Once plugged in for charging, the vehicle 102 receives a charging current from the power source 104 to charge the energy storage device 106. The charging current, as per the present subject matter, isgenerated by the power source 104 based on a charging profile determined by the vehicle 102 based on certain current charging prerequisites or charging requirements of the user for effecting efficient and quick charging of the energy storage device 106. In an example, the vehicle 102 may include a control unit 108 which facilitates determination of an efficient and quick charging profile for charging the energy storage device based on parametric and characteristic data of the energy storage device 106. In an example, the control unit 108 may be implemented as a hardware or software-based application on the vehicle 102 (as described in FIG. 1 ). However, other implementations of the control unit 108 may also be possible, without deviating from the scope of the present subject matter.

[0018] In operation, once vehicle 102 is plugged in for charging, the control unit 108 obtains a plurality of charging attributes of the energy storage device 106. Examples of charging attributes include, but are not limited to, current SoC, current temperature, and target SoC. The plurality of charging attributes are either obtained from the energy storage device 106 or from the user operating the vehicle 102. For example, charging attributes, such as current SoC and current temperature are obtained by control unit 108 from the energy storage device 106. On the other hand, target SoC is obtained by the control unit 108 from a Human Machine Interface (HMI) (not shown in FIG. 1 ) installed on the vehicle 102. In such case, the user operating the vehicle 102 may enter or provide the target SoC up to which the user wants to charge the energy storage device 106 on the HMI of the vehicle 102.

[0019] Continuing further, once the charging attributes are obtained, the control unit 108 extract charging characteristics of the energy storage device from a data repository (not shown in FIG. 1 ). In an example, the charging characteristics include change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates (or c- rates) for the energy storage device. Such charging characteristics are recorded or maintained by various manufacturers or suppliers, or industryexperts based on previous charging of the similar type of energy storage device. For example, the energy storage device, when charged in the past, may would have experienced changes in SoC per minute and changes in temperature per minute. The same data is stored as the charging characteristics in the data repository.

[0020] Returning to the present example, thereafter, the control unit 108 generates a charging time function which is to indicate a linear relation between total time to charge (TTC) of the energy storage device 106 with a plurality of charging time corresponding to the plurality of charging rates (or c-rates). In an example, the charging time function is a summation of plurality of charging times (e.g., ti to tg) with each corresponding to one of the plurality of charging rates (e.g., ci to eg). For example, charging time function may written as TTC = ti, wherein ‘i’ varies from 1 to 9 and each ‘ti’ correspond to one of the plurality of charging rates.

[0021] Once generated, the control unit 108 subject the charging time function to be optimized with respect to a plurality of charging attributes constraints to determine a charging profile for charging the energy storage device 106. While optimizing, the control unit 108 applies values of the plurality of charging attributes and charging characteristics to the plurality of charging attributes constraints to optimize (i.e., minimize) the charging time function. In an example, the control unit 108 performs a dual simplex method to minimize the charging time function with respect to the plurality of charging attributes constraints.

[0022] Thereafter, the data which is obtained after minimization of the charging time function is used to formulate a charging profile for charging the energy storage device 106. In an example, the charging profile includes a set of values of a charging parameter. Examples of charging parameters include, but are not limited to, c-rate for charging and a charging time corresponding to the c-rate. For example, if after minimization, as a result of dual simplex method, the control unit 108 determines that charging of the energy storage device 106 needs to be performed with c-rate t1 and t5 for5 minutes and 15 minutes, respectively. Then, the control unit 108 formulates or determines the charging profile to include these details as values for charging parameters in the charging profile.

[0023] Continuing further, once formulated, the control unit 108 generates a charging signal to be transmitted to the power source 104 which is connected to the energy storage device 106. In an example, the charging signal includes the charging profile indicating different charging parameters to be used for charging the energy storage device 106. Based on the charging signal, the power source 104 provides a charging current to the vehicle 102 for charging the energy storage device 106. For example, in response to transmitted charging signal, the control unit 108 or vehicle 102 receives the charging current from the power source 104 to charge the energy storage device 106. Subsequently, the control unit 108 passes this charging current to the energy storage device 106 to effectuate the charging.

[0024] The manner in which the control unit 108 obtain different charging attributes and characteristics from different components of vehicle 102 or from data repository is further described in conjunction with FIG. 2.

[0025] FIG. 2 illustrates a charging environment 200 depicting block diagram of various components of an electric vehicle 202 (referred to as vehicle 202) and other components which are in communication with the vehicle 202 for effecting charging of the vehicle 202, according to an example of the present subject matter. In an example, the vehicle 202 is similar to that of vehicle 102, includes a control unit 204 for performing processes related to the functional aspects of vehicle 202, e.g., control unit 204 is to formulate a charging profile which is to be used for charging a storage device of the vehicle 202. Further, the vehicle 202 includes an energy storage device 206 for powering different components of the vehicle 202 and a human machine interface (HMI) 208 for either receiving user input from a user or displaying information to the user.

[0026] When the energy storage device 206 is discharged or expended, the vehicle 202 is connected to an external power supply source 210 for enabling charging of the energy storage device 206. Once connected, the control unit 204 formulates the charging profile to be shared with the power supply source 210. The charging profile prescribes a value of charging parameter to be used for charging the energy storage device 206 of the vehicle 202. Examples of such charging parameters include, but are not limited to, charging rates (c-rates) and charging time corresponding to c- rates. Based on the charging profile, the power supply source 210 (power source 210) provides a charging current to the vehicle 202 to be used for recharging the energy storage device 206. In an example, the charging current provided by the power source 210 may change based on the information provided in the charging profile, i.e., the charging current dynamically changes over a period of time based on the charging profile.

[0027] The control unit 204 of the vehicle 202 may be communicatively coupled to a data repository 212 through a network (not shown in FIG. 2). The data repository 212 may further include a charging characteristic(s) 214 for a plurality of energy storage devices. In an example, the charging characteristic(s) 214 include change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates for the plurality of energy storage devices. For example, the battery manufacturer or supplied would have conducted certain charging or discharging operations (with different charging rates) on a variety of energy storage devices having different device attributes. The data obtained during such operations is stored in the data repository 212 segregated based on the device attributes of the energy storage devices. Therefore, based on the device attributes, corresponding charging characteristic(s) 214 may be obtained from data repository 212 to be used in formulating the charging profile for charging the energy storage device 206 of the vehicle 202.

[0028] The charging characteristic(s) 214, although depicted as being obtained from a single repository, such as data repository 212, may also beobtained from multiple other source either external or internally present within the vehicle 202 without deviating from the scope of the present subject matter. In such cases, each of such multiple repositories may be interconnected through a network (not shown in FIG. 2). The network may be a private network or a public network and may be implemented as a wired network, a wireless network, or a combination of a wired and wireless network. The network may also include a collection of individual networks, interconnected with each other and functioning as a single large network, such as the internet. Examples of such individual networks include, but are not limited to, Global System for Mobile Communication (GSM) network, Universal Mobile Telecommunications System (UMTS) network, Personal Communications Service (PCS) network, Time Division Multiple Access (TDMA) network, Code Division Multiple Access (CDMA) network, Next Generation Network (NGN), Public Switched Telephone Network (PSTN), Long Term Evolution (LTE), and Integrated Services Digital network (ISDN).

[0029] The control unit 204 further includes a processor 216, interface(s) 218, a memory(s) 220, and a data 222. The processor 216 may be implemented as microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and / or other devices that manipulate signals based on operational instructions. The interface(s) 218 may allow the connection or coupling of the control unit 204 with one or more other devices, through a wired (e.g., Local Area Network, i.e., LAN) connection or through a wireless connection (e.g., Bluetooth®, Wi-Fi). The interface(s) 218 may also enable intercommunication between different logical as well as hardware components of the control unit 204.

[0030] The memory(s) 220 may be a computer-readable medium, examples of which include volatile memory (e.g., RAM), and / or non-volatile memory (e.g., Erasable Programmable read-only memory, i.e., EPROM, flash memory, etc.). The memory(s) 220 may be an external memory, or internal memory, such as a flash drive, a compact disk drive, an externalhard disk drive, or the like. The memory(s) 220 may further include data which either may be utilized or generated during the operation of the control unit 204.

[0031] The data 222, on the other hand, includes a current SoC 224, a current temperature 226, a target SoC 228, charging characteristic(s) 214, a charging profile 230, and other data 232. Further, the other data 232, amongst other things, may serve as a repository for storing data that is processed, or received, or generated as a result of the execution of instructions comprised in the control unit 204. In an example, the current SoC 224 and the current temperate 226 represents SoC and temperature, respectively, of the energy storage device 206 and is obtained from the energy storage device 206. For example, there are plurality of sensors installed or attached in the vicinity of the energy storage device 206 which monitors several attributes, such as SoC and temperature, of the energy storage device 206 to be provided to the control unit 204. Further, the target SoC 228 is the SoC up to which the charging of the energy storage device 206 needs to be performed. In one example, it is entered by a user on HMI 208 or it may be a default value, e.g., 100% SoC.

[0032] In another example, the control unit 204 may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or in combination thereof. For a firmware and / or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein.

[0033] In operation, when the energy storage device 206 of the vehicle 202 is discharged or expended and needs to be charged, the vehicle 202 is connected to the power source 210 to recharge the energy storage device206 (e.g., as depicted in FIG. 1 by connecting vehicle 102 with the power source 104). In such an instance, once the vehicle 202 is plugged in for charging, the control unit 204 of the vehicle 202 obtains a plurality of charging attributes of the energy storage device 206. Examples of such plurality of charging attributes include, but are not limited to, current SoC, current temperature, and target SoC. The plurality of charging attributes are either obtained from the energy storage device 206 or from the HMI 208 of the vehicle 202.

[0034] For example, charging attributes, such as current SoC 224 and current temperature 226 are obtained by control unit 204 from the energy storage device 206 (as depicted by communication link 234). On the other hand, target SoC 228 is obtained by the control unit 204 from the HMI 208 which is installed on the vehicle 202 (as depicted by communication link 236). In such a case, the user operating the vehicle 202 or the person who is responsible for monitoring the charging of the vehicle 202 may enter or provide the target SoC 228 on the HMI up to which the user wants to charge the energy storage device 206.

[0035] Continuing further, once the charging attributes are obtained, the control unit 204 extracts charging characteristic(s) 214 of the energy storage device 206 from the data repository (as depicted by communication link 238). As described above as well, the charging characteristic(s) 214 include change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates (or c-rates) for the plurality of energy storage device. Such charging characteristics are recorded or maintained by various manufacturers or suppliers, or industry experts based on previous charging operation of the similar type of energy storage device. For example, the energy storage device, when charged in the past, would have experienced changes in SoC per minute and changes in temperature per minute. The same data is recorded and stored in the data repository 212 as the charging characteristic(s) 214. Such data is updatedcontinuously based on charging operations performed on various energy storage devices.

[0036] In an example, the data repository 212 include charging characteristic(s) 214 of plurality of energy storage devices. In order to obtain relevant charging characteristic(s) 214 corresponding to the energy storage device 206, the control unit 204 derives or determines a plurality of device attributes of the energy storage device 206. In one example, the control unit 204 generates a request signal for the energy storage device 206 which in response to this signal provides the plurality of device attributes to the control unit 204. Based on the determined device attributes, the control unit 204 selects charging characteristic(s) 214 corresponding to the energy storage device 206 from the data repository 212. Since data repository 212 includes charging characteristic(s) 214 of plurality of energy storage devices segregated based on their device attributes, the control unit 204 searches and selects charging characteristic(s) 214 corresponding to the determined device attributes. Examples of plurality of device attributes include, but are not limited to, charging capacity and chemical formulation of the energy storage devices.

[0037] Returning to the present example, thereafter, the control unit 204 generates a charging time function. In an example, the charging time function indicates a linear relation between total time to charge (TTC) of the energy storage device 206 with a plurality of charging time corresponding to the plurality of charging rates (or c-rates). In an example, the charging time function is the summation of plurality of charging times (e.g., ti to tg) with each corresponding to one of the plurality of charging rates (e.g., ci to eg). For example, charging time function may be written as TTC = ti, wherein ‘i’ varies from 1 to 9 and each ‘ti’ correspond to one of the plurality of charging rates. It may be noted that, values of ‘i’ are exemplary and it may take any of the possible values based on the possible charging rates.

[0038] Once generated, the control unit 204 subject the charging time function to be optimized with respect to a plurality of charging attributesconstraints to determine a charging profile, such as charging profile 230, for charging the energy storage device 206. While optimizing, the control unit 108 applies values of the plurality of charging attributes and charging characteristic(s) 214 to the plurality of charging attributes constraints to optimize (i.e., minimize) the charging time function. Specifically, the main objection of the present subject matter is to reduce the TTC or minimize TTC while achieving the required target SoC 228 and keeping the temperature of the energy storage device 206 under the desired threshold.

[0039] In an example, the charging time function as described above is a linear equation which may be optimized (i.e., minimized) using linear programming techniques with respect to certain constraints. There are number of techniques available to optimize such equations. In an example, the control unit 204 performs a dual simplex method to minimize the charging time function with respect to the plurality of charging attributes constraints to determine the charging profile 230. In an example, the plurality of charging attributes constraints are:A emp <= temp imit - current temperatureA_SoC <= target SoC - current SoCA_SoC >= min ((tempjimit - current temperature f, target SoC - current SoC))A_SoC_X1 >= max (min (X1 , target SoC) - max (current SoC, X2), 0) A_SoC_X2 < max (min (X2, target SoC) - current SoC, 0).

[0040] In an example, tempjimit is the maximum allowable temperature for charging, f is a factor based on the ratio of temperature change per minute to the SoC change per minute of the lowest charging rate, ‘XT is the SoC above which certain charging rates are not allowed due to voltage buildup constraints, X2’ is the SoC below which only certain C rates are allowed. In one example, as per industry standards, the temperature of the energy storage device should not increase beyond 45C (i.e., the tempjimit is 45C) while charging, however, it may take any possible value based on the requirement.

[0041] It may be noted that, the above-described constraints are derived or formulated to achieve best charging performance by keeping various parameters and attributes of the energy storage device within the limit. Examples of such limiting criterions include, but are not limited to, temperature should not increase beyond the threshold value, fast charging should be achieved, most effective charging rates should be picked, etc.

[0042] Once the optimization (or specifically minimization) of the charging time function is done, the control unit 204 utilizes the data obtained as a result of minimization to formulate the charging profile 230 for charging the energy storage device 206. In an example, the charging profile 230 includes a set of values of a charging parameter. Examples of charging parameters include, but are not limited to, c-rate for charging and a charging time corresponding to the c-rate. For example, if after minimization, as a result of dual simplex method, the control unit 204 determines that charging of the energy storage device 206 needs to be performed with c-rate ci and C5 for 5 minutes (ti) and 15 minutes (tz), respectively. Then, the control unit 204 formulates or determines the charging profile 230 to include these details as values for charging parameters in the charging profile 230.

[0043] Continuing further, once formulated, the control unit 204 generates a charging signal to be transmitted to the power source 210 (as depicted by arrow 240 in FIG. 2). In an example, the charging signal includes the charging profile 230 indicating different charging parameters to be used for providing charging current to the energy storage device 206. Based on the charging signal, the power source 210 provides a charging current to the vehicle 202 for charging the energy storage device 206 (as depicted by arrow 242 in FIG. 2). For example, in response to transmitted charging signal, the control unit 204 or vehicle 202 receives the charging current from the power source 210 to charge the energy storage device 206.

[0044] FIG. 3 illustrates an example method 300 for generating a charging profile and subsequently using the charging profile for charging an energy storage device, in accordance with examples of the present subjectmatter. The order in which the above-mentioned methods are described is not intended to be construed as a limitation, and some of the described method blocks may be combined in a different order to implement the methods, or alternative methods.

[0045] Furthermore, the above-mentioned methods may be implemented in a suitable hardware, computer-readable instructions, or combination thereof. The steps of such methods may be performed by either a system under the instruction of machine executable instructions stored on a non-transitory computer readable medium or by dedicated hardware circuits, microcontrollers, or logic circuits. For example, the methods may be performed by a control unit, such as the control unit 204 or control unit 108 of the electric vehicle, such as vehicle 202 or vehicle 102. Herein, some examples are also intended to cover non-transitory computer readable medium, for example, digital data storage media, which are computer readable and encode computer-executable instructions, where said instructions perform some or all the steps of the above-mentioned methods.

[0046] In an example, the method 300 may be implemented by the control unit 204 to determine the charging profile 230 which is to be used for charging the energy storage device 206. At block 302, a plurality of charging attributes of an energy storage device are obtained. For example, when the energy storage device 206 of the vehicle 202 is discharged or expended and needs to be charged, the vehicle 202 is connected to the power source 210 to recharge the energy storage device 206. In such an instance, once the vehicle 202 is plugged in for charging, the control unit 204 of the vehicle 202 obtains a plurality of charging attributes of the energy storage device 206. Examples of such plurality of charging attributes include, but are not limited to, current SoC, current temperature, and target SoC. The plurality of charging attributes are either obtained from the energy storage device 206 or from the HMI 208 of the vehicle 202.

[0047] For example, charging attributes, such as current SoC 224 and current temperature 226 are obtained by control unit 204 from the energy storage device 206 (as depicted by communication link 234). On the other hand, target SoC 228 is obtained by the control unit 204 from the HMI 208 which is installed on the vehicle 202 (as depicted by communication link 236). In such a case, the user operating the vehicle 202 or the person who is responsible for monitoring the charging of the vehicle 202 may enter or provide the target SoC 228 on the HMI up to which the user wants to charge the energy storage device 206.

[0048] At block 304, charging characteristics of the energy storage device are extracted from a data repository. For example, once the charging attributes are obtained, the control unit 204 extracts charging characteristic(s) 214 of the energy storage device 206 from the data repository (as depicted by communication link 238). As described above as well, the charging characteristic(s) 214 include change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates (or c-rates) for the plurality of energy storage device. Such charging characteristics are recorded or maintained by various manufacturers or suppliers, or industry experts based on previous charging operation of the similar type of energy storage device. For example, the energy storage device, when charged in the past, would have experienced changes in SoC per minute and changes in temperature per minute. The same data is recorded and stored in the data repository 212 as the charging characteristic(s) 214. Such data is updated continuously based on charging operations performed on various energy storage devices.

[0049] At block 306, a charging time function is generated. For example, the control unit 204 generates a charging time function. In an example, the charging time function indicates a linear relation between total time to charge (TTC) of the energy storage device 206 with a plurality of charging time corresponding to the plurality of charging rates (or c-rates). In an example, the charging time function is the summation of plurality of chargingtimes (e.g., ti to tg) with each corresponding to one of the plurality of charging rates (e.g., ci to eg). For example, charging time function may be written as TTC = ti, wherein ‘i’ varies from 1 to 9 and each ‘ti’ correspond to one of the plurality of charging rates. It may be noted that, values of ‘i’ are exemplary and it may take any of the possible values based on the possible charging rates.

[0050] At block 308, the charging time function is subjected to be optimized with respect to a plurality of charging attributes constraints to determine a charging profile. For example, the control unit 204 subject the charging time function to be optimized with respect to a plurality of charging attributes constraints to determine a charging profile, such as charging profile 230, for charging the energy storage device 206. While optimizing, the control unit 204 applies values of the plurality of charging attributes and charging characteristic(s) 214 to the plurality of charging attributes constraints to optimize (i.e., minimize) the charging time function. Specifically, the main objection of the present subject matter is to reduce the TTC or minimize TTC while achieving the required target SoC 228 and keeping the temperature of the energy storage device 206 under the desired threshold.

[0051] Once the optimization or specifically minimization of the charging time function is done, the control unit 204 utilizes the data obtained as a result of minimization to formulate the charging profile 230 for charging the energy storage device 206. In an example, the charging profile 230 includes a set of values of a charging parameter. Examples of charging parameters include, but are not limited to, c-rate for charging and a charging time corresponding to the c-rate. For example, if after minimization, as a result of dual simplex method, the control unit 204 determines that charging of the energy storage device 206 needs to be performed with c-rate ci and C5 for 5 minutes (ti) and 15 minutes (tz), respectively. Then, the control unit 204 formulates or determines the charging profile 230 to include these details as values for charging parameters in the charging profile 230.

[0052] At block 310, a charging signal including the charging profile is generated to be transmitted to a power supply source. For example, the control unit 204 generates a charging signal to be transmitted to the power source 210 (as depicted by arrow 240 in FIG. 2). In an example, the charging signal includes the charging profile 230 indicating different charging parameters to be used for providing charging current to the energy storage device 206.

[0053] At block 312, a charging current is received from the power supply based on the charging profile to charge the energy storage device. For example, the power source 210 provides a charging current to the vehicle 202 for charging the energy storage device 206 (as depicted by arrow 242 in FIG. 2). For example, in response to transmitted charging signal, the control unit 204 or vehicle 202 receives the charging current from the power source 210 to charge the energy storage device 206.

[0054] Although implementations of present subject matter have been described in language specific to structural features and / or methods, it is to be noted that the present subject matter is not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed and explained in the context of a few implementations for the present subject matter.

Claims

I / We Claim:

1. A control unit is to: obtain a plurality of charging attributes of an energy storage device, wherein the plurality of charging attributes comprises a current state of charge (SoC), a current temperature, and a target SoC of the energy storage device; extract charging characteristics of the energy storage device from a data repository, wherein the charging characteristics comprises change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates for the energy storage device; generate a charging time function indicating linear relation between total time to charge (TTC) of the energy storage device with a plurality of charging time corresponding to the plurality of charging rates; and subject the charging time function to be optimized with respect to a plurality of charging attributes constraints to determine a charging profile with plurality of charging attributes and charging characteristics applied to the plurality of charging attributes constraints, wherein the charging profile comprises a value of a charging parameter.

2. The control unit as claimed in claim 1 , wherein the charging parameter is a c-rate for charging and a charging time corresponding to the c-rate.

3. The control unit as claimed in claim 1 , wherein the current SoC and current temperature of the energy storage device are obtained when the energy storage device is connected to a power supply for charging.

4. The control unit as claimed in claim 1 , wherein the target SoC is provided by a user on a Human Machine Interface (HMI) installed on an electric vehicle.

5. The control unit as claimed in claim 1 , wherein to subject the charging time function to be optimized, the control unit is to:subject the charging time function for minimization with respect to the plurality of charging attributes constraints using a dual simplex method to determine a minimized time to charge (TTC).

6. The control unit as claimed in claim 5, wherein the charging time function is:TTC = ti, wherein ‘i’ varies from 1 to 9 and each ‘ti’ correspond to one of the plurality of charging rates; wherein the plurality of charging attributes constraints are:A_temp <= temp_limit - current temperatureA_SoC <= target SoC - current SoCA_SoC >= min ((temp_limit - current temperature)*f, target SoC - current SoC))A_SoC_X1 >= max (min (X1 , target SoC) - max (current SoC, X2), 0)A_SoC_X2 < max (min (X2, target SoC) - current SoC, 0) wherein tempjimit is the maximum allowable temperature for charging, T is a factor based on the ratio of temperature change per minute to the SoC change per minute of the lowest charging rate, ‘XT is the SoC above which certain charging rates are not allowed due to voltage buildup constraints, X2’ is the SoC below which only certain C rates are allowed.

7. The control unit as claimed in claim 1 , wherein the control unit is to: generate a charging signal comprising the charging profile to be transmitted to a power supply connected to the energy storage device for charging; and receive a charging current from the power supply to charge the energy storage device based on the charging profile comprised in the charging signal.

8. The control unit as claimed in claim 1 , wherein to extract charging characteristics of the energy storage device, the control unit is to:determine a plurality of device attributes of the energy storage device, wherein the plurality of device attributes comprise charging capacity and chemical formulation of the energy storage device; and select charging characteristics of the energy storge device from the data repository based on the plurality of device attributes, wherein the data repository stores charging characteristics of a plurality of energy storage devices segregated based on device attributes.

9. A method comprising: obtaining a plurality of charging attributes of an energy storage device, wherein the plurality of charging attributes comprises a current state of charge (SoC), a current temperature, and a target SoC of the energy storage device; extracting charging characteristics of the energy storage device from a data repository, wherein the charging characteristics comprises change in SoC per minute and change in temperature per minute corresponding to a plurality of charging rates for the energy storage device; generating a charging time function indicating linear relation between total time to charge (TTC) of the energy storage device with a plurality of charging time corresponding to the plurality of charging rates; and subjecting the charging time function to be optimized with respect to a plurality of charging attributes constraints to determine a charging profile with plurality of charging attributes and charging characteristics applied to the plurality of charging attributes constraints, wherein the charging profile comprises a value of a charging parameter.

10. The method as claimed in claim 9, wherein the charging parameter is a charging current, a charging time, or a combination thereof.1 1 . The method as claimed in claim 9, wherein the current SoC and current temperature of the energy storage device are obtained when the energy storage device is connected to a power supply for charging.

12. The method as claimed in claim 9, wherein the target SoC is provided by a user on a Human Machine Interface (HMI) installed on an electric vehicle.

13. The method as claimed in claim 9, wherein while subjecting the charging time function to be optimized, the method comprises: subjecting the charging time function for minimization with respect to the plurality of charging attributes constraints using a dual simplex method to determine a minimized time to charge (TTC); wherein the charging time function is:TTC = ti, wherein ‘i’ varies from 1 to 9 and each ‘ti’ correspond to one of the charging rates; wherein the plurality of charging attributes constraints are:A_temp <= temp_limit - current temperatureA_SoC <= target SoC - current SoCA_SoC >= min ((temp_limit - current temperature)*f, target SoC - current SoC))A_SoC_X1 >= max (min (X1 , target SoC) - max (current SoC, X2), 0)A_SoC_X2 < max (min (X2, target SoC) - current SoC, 0) wherein tempjimit is the maximum allowable temperature for charging, ‘f’ is a factor based on the ratio of temperature change per minute to the SoC change per minute of the lowest charging rate, ‘XT is the SoC above which certain charging rates are not allowed due to voltage buildup constraints, X2’ is the SoC below which only certain C rates are allowed.

14. The method as claimed in claim 9, wherein the method comprises: generating a charging signal comprising the charging profile to be transmitted to a power supply connected to the energy storage device for charging; andreceiving a charging current from the power supply based on the charging profile comprised in the charging signal to charge the energy storage device.

15. The method as claimed in claim 9, wherein for extracting charging characteristics of the energy storage device, the method comprises: determining a plurality of device attributes of the energy storage device, wherein the plurality of device attributes comprise charging capacity and chemical formulation of the energy storage device; and selecting charging characteristics of the energy storage device from the data repository based on the plurality of device attributes, wherein the data repository stores charging characteristics of a plurality of energy storage devices segregated based on device attributes.

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