CHARGING SYSTEM FOR AN ELECTRIC VEHICLE TO IMPLEMENT A REAL-TIME CHANGE IN THE CHARGING CURRENT AND CHARGING CURRENT
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- GM GLOBAL TECHNOLOGY OPERATIONS LLC
- Filing Date
- 2023-04-25
- Publication Date
- 2026-07-09
AI Technical Summary
Existing charging systems for electric vehicles do not dynamically adjust the terminal voltage (CV) and shutdown current (CC) combination pairs based on the type of charging station, leading to potential negative impacts on battery life, resistance, and charge completion accuracy.
A charging system that includes a control module to select optimal CV and CC combination pairs in real-time based on factors such as charging station type, battery life expectancy, resistance, and charge accuracy, minimizing degradation and optimizing charging time.
The system enhances battery life expectancy, improves charge completion accuracy, and reduces charging time by dynamically selecting CV and CC pairs tailored to the specific conditions of each charging event.
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Abstract
Description
INTRODUCTION
[0001] The information provided in this section serves to present the general context of the disclosure. Works of the inventors mentioned herein, insofar as they are described in this section, as well as aspects of the description that may not have been prior art at the time of filing, are neither expressly nor implicitly recognized as prior art with respect to the present disclosure.
[0002] The present disclosure relates to charging systems for rechargeable energy storage systems of vehicles.
[0003] Electric vehicles, such as fully electric vehicles, battery electric vehicles (BEVs), and hybrid electric vehicles, including plug-in hybrid electric vehicles (PHEVs), contain high-voltage battery packs (HS battery packs). The HS battery packs supply high-voltage direct current (DC) loads and an auxiliary power module that converts the high voltage to a low voltage to charge a low-voltage (LV) power source (or battery). The LV power source is used to supply LV DC loads. HS loads can include motors used for propulsion, as well as other HS loads. Examples of LV loads include lights, window and seat motors, door locks, infotainment systems, and so on. HS battery packs can have terminals rated at, for example, 400 V or 800 V. LV power sources can have terminals for, for example, charging cables, power supplies, and other accessories. B. 12 V or 48 V. SUMMARY
[0004] A charging system for an electric vehicle is disclosed. The charging system comprises: a storage device configured to store combination pairs of terminal voltage (CV) and cutoff current (CC); a charging socket configured to connect to an external charging station; and an internal charging circuit. The internal charging circuit comprises: a high-voltage DC bus connected to a rechargeable energy storage system; and a control module configured to communicate with the external charging station and determine the charging capabilities of the external charging station and the internal charging circuit, select one of the CV and CC combination pairs based on the charging capabilities of the external charging station and the internal charging circuit, and initiate charging of the rechargeable energy storage system based on the selected CV and CC combination pair.
[0005] In other features, the charging system further includes an internal charging module configured to: convert an AC voltage received from the external charging station via the charging socket into a DC voltage and supply the DC voltage to the high-voltage DC bus; indicate the AC voltage to the control module; and receive an instruction from the control module to convert the AC voltage into the CV of one of the CV and CC combination pairs in order to charge the rechargeable energy storage system.
[0006] In other features, the control module is configured to: look up or calculate an estimated charging power value for each of at least some of the CV and CC combination pairs to provide charging power values; and, based on the charging power values, select the CV and CC combination pair with the estimated charging power that is closest to, but not greater than, a smaller value of a) a power capacity of the external charging station and b) a power capacity of the internal charging circuit.
[0007] In other features, the control module is configured to: determine a depth of discharge; look up or calculate an estimated lifetime of the rechargeable energy storage system for each of at least some of the CV and CC combination pairs; and, based on the depth of discharge, select the one of the CV and CC combination pairs that results in a lifetime of the rechargeable energy storage system that is closest to a target lifetime without being shorter than the target lifetime.
[0008] In other features, the control module is configured to: estimate resistance uncertainty and / or growth of the rechargeable energy storage system; based on resistance uncertainty and / or growth, look up or calculate the estimated charge-end-state-of-charge uncertainty of the rechargeable energy storage system for each of at least some of the CV and CC combination pairs; and based on the estimated charge-end-state-of-charge uncertainties, select one of the CV and CC combination pairs, resulting in a charge-end-state-of-charge uncertainty that is close to a charge-end-state-of-charge target uncertainty without exceeding the charge-end-state-of-charge target uncertainty.
[0009] In other features, the control module is configured to: estimate a resistance change of the rechargeable energy storage system for each of at least some of the CV and CC combination pairs; estimate an open-circuit voltage based on the resistance change and the current supplied to the rechargeable energy storage system; estimate the state of charge based on the estimated open-circuit voltage; determine a state-of-charge error based on the estimated state of charge and a target state of charge; and select one of the CV and CC combination pairs with the highest corresponding power and with a state-of-charge error within a specified error range.
[0010] In other features, the control module is configured to: determine if the external charging station is a public station; determine if the external charging station has time-based charging costs; in response to the determination that the external charging station is a public station and has time-based charging costs, look up or calculate estimated charging power values for each of at least some of the CV and CC combination pairs to provide charging power values; and, based on the charging power values, select the CV and CC combination pair with the estimated charging power that is closest to, but not greater than, the smaller of a) a power capacity of the external charging station and b) a power capacity of the internal charging circuit.
[0011] In other features, the control module is configured to: determine whether the external charging station is a public station; in response to the determination that the external charging station is a public station, implement a charging time minimization procedure to select one of the CV and CC combination pairs; and in response to the determination that the external charging station is not a public station, implement a maximum lifetime charging procedure to select one of the CV and CC combination pairs.
[0012] In other features, the control module is configured to: determine a depth of discharge; determine a resistance uncertainty or resistance growth of the rechargeable energy storage system; filter out some of the CV and CC combination pairs that do not meet a lifetime requirement for the rechargeable energy storage system, based on the depth of discharge, to provide a first resulting set of CV and CC combination pairs; filter out some of the first resulting set of CV and CC combination pairs that do not meet a state-of-charge accuracy requirement to provide a second resulting set of CV and CC combination pairs; and implement a charging time minimization procedure to select one of the CV and CC combination pairs from the second resulting set of CV and CC combination pairs.
[0013] In other features, the control module is configured to: determine whether the external charging station is a DC charging station or an AC charging station; in response to the external charging station being a DC charging station, instruct the external charging station to charge the rechargeable energy storage system based on the selected CV and CC combination pair; and in response to the external charging station being an AC charging station, charge the rechargeable energy storage system based on the selected CV and CC combination pair.
[0014] Further features disclose a method for charging a rechargeable energy storage system of an electric vehicle. The method comprises: storing combination pairs of terminal voltage (CV) and cutoff current (CC); transferring current between an external charging station and a high-voltage DC bus of an internal charging circuit of the electric vehicle, wherein the high-voltage DC bus is connected to a rechargeable energy storage system; communicating with the external charging station and determining the charging capabilities of the external charging station and the internal charging circuit; selecting one of the CV and CC combination pairs based on the charging capabilities of the external charging station and the internal charging circuit; and charging the rechargeable energy storage system based on the selected CV and CC combination pair.
[0015] Other features of the method include: converting an alternating current voltage received from the external charging station via the charging socket into a direct current voltage and supplying the direct current voltage to the high-voltage direct current bus; determining the alternating current voltage; and converting the alternating current voltage into the CV of one of the CV and CC combination pairs for charging the rechargeable energy storage system.
[0016] In other features, the method further includes: looking up or calculating an estimated charging power value for each of at least some of the CV and CC combination pairs to provide charging power values; and, based on the charging power values, selecting the one of the CV and CC combination pairs with the estimated charging power that is closest to, but not greater than, a smaller value of a) a power capacity of the external charging station and b) a power capacity of the internal charging circuit.
[0017] In other features, the procedure further includes: determining a depth of discharge; looking up or calculating an estimated lifetime of the rechargeable energy storage system for each of at least some of the CV and CC combination pairs; and, based on the depth of discharge, selecting one of the CV and CC combination pairs, resulting in a lifetime of the rechargeable energy storage system that is closest to a target lifetime without being shorter than the target lifetime.
[0018] In other features, the procedure further includes: estimating resistance uncertainty and / or growth of the rechargeable energy storage system; based on the resistance uncertainty and / or growth, looking up or calculating the estimated charge-end-state-of-charge uncertainty of the rechargeable energy storage system for each of at least some of the CV and CC combination pairs; and based on the estimated charge-end-state-of-charge uncertainties, selecting one of the CV and CC combination pairs, resulting in a charge-end-state-of-charge uncertainty close to a charge-end-state-of-charge target uncertainty without exceeding the charge-end-state-of-charge uncertainty.
[0019] In other features, the method further includes: for each of at least some of the CV and CC combination pairs, estimating a resistance change of the rechargeable energy storage system, estimating an open-circuit voltage based on the resistance change and the current supplied to the rechargeable energy storage system, estimating the state of charge based on the estimated open-circuit voltage, and determining a state-of-charge error based on the estimated state of charge and a target state of charge; and selecting one of the CV and CC combination pairs with the highest corresponding power and with a state-of-charge error within a specified error range.
[0020] In other features, the procedure further includes: determining whether the external charging station is a public station; determining whether the external charging station has time-based charging costs; in response to determining that the external charging station is a public station and that it has time-based charging costs, looking up or calculating estimated charging power values for each of at least some of the CV and CC combination pairs to provide a variety of charging power values; and, based on the variety of charging power values, selecting the one of the CV and CC combination pairs with the estimated charging power that is closest to, but not greater than, a) a power capacity of the external charging station and b) a power capacity of the internal charging circuit.
[0021] In other features, the procedure further includes: determining whether the external charging station is a public station; in response to determining that the external charging station is a public station, implementing a charging time minimization procedure to select one of the CV and CC combination pairs; and in response to determining that the external charging station is not a public station, implementing a maximum lifetime charging procedure to select one of the CV and CC combination pairs.
[0022] In other features, the method further includes: determining a depth of discharge; determining a resistance uncertainty or resistance growth of the rechargeable energy storage system; based on the depth of discharge, filtering out some of the CV and CC combination pairs that do not meet a lifetime requirement for the rechargeable energy storage system to provide a first resulting set of CV and CC combination pairs; filtering out some of the first resulting set of CV and CC combination pairs that do not meet a state-of-charge accuracy requirement to provide a second resulting set of CV and CC combination pairs; and implementing a charging time minimization procedure to select one of the CV and CC combination pairs from the second resulting set of CV and CC combination pairs.
[0023] In other features, the method further includes: determining whether the external charging station is a DC charging station or an AC charging station; in response to the finding that the external charging station is a DC charging station, instructing the external charging station to charge the rechargeable energy storage system based on the selected CV and CC combination pair; and in response to the finding that the external charging station is an AC charging station, charging the rechargeable energy storage system based on the selected CV and CC combination pair.
[0024] Further applications of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples serve only for illustration and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present disclosure will be better understood from the detailed description and the accompanying drawings, whereby: Fig. 1 An example of the representation of current and voltage curves for two sets of combinations of terminal voltage (CV) and cut-off current (CC) is shown, which result in the same open-circuit voltage (OCV); Fig. 2 a functional block diagram of an exemplary charging system with a vehicle integration control module that implements a CV and CC application according to the present disclosure; Fig. 3 represents an example of a method for minimizing the loading time when changing a CV and CC combination pair in real time and according to the present disclosure; Fig. 4 represents an example of a RESS charging method for maximum lifetime for changing a CV and CC combination pair in real time and according to the present disclosure; Fig. 5 is an example of how to illustrate battery lifespan and charging time in comparison to depth of discharge (DoD); Fig. Figure 6 is an example of the representation of the percentage increase in cell resistance at the beginning of the lifetime compared to cell age for various applications; Fig. 7 represents a method for lowering a CV and CC combination point in real time as a function of the RESS resistance growth and / or uncertainty according to the present disclosure; Fig. 8 represents an example method for adjusting a CV and CC combination pair based on changes in the RESS resistance and the state of charge error (SOC error) according to the present disclosure; Fig. 9 represents an example method for changing a CV and CC combination pair in real time depending on whether an external charger is a public charger with charging time-based costs according to the present disclosure; and Fig. 10 represents an example of an arbitration procedure for matching a CV and CC combination pair in real time and in accordance with the present disclosure.
[0026] Reference symbols can be reused in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION
[0027] High-voltage (HS) battery packs for electric vehicles are charged by connecting the electric vehicles to external charging stations. During a charging process, targets for a full charge to a specific state of charge (SOC) (e.g., 96%) are achieved. These full charge targets include a pseudo-steady-state terminal constant voltage (CV) and a pseudo-steady-state constant voltage (CC). An open-circuit voltage (OCV) at rest corresponds to the target SOC. The SOC of a power source refers to the state of charge of the power source relative to its capacity. The SOC of a cell and / or battery pack module can refer to, for example, the voltage, current, and / or the amount of available energy stored in the cell and / or battery pack module. To achieve a full charge, the target CV and CC values are reached.A CV and CC combination pair can be determined empirically and / or analytically such that it results in an OCV at rest that corresponds to the desired SOC at full charge.
[0028] Fig. Figure 1 shows an example of current and voltage curve plots for two sets of CV and CC combination pairs providing the same OCV. A first voltage curve 100, a second voltage curve 102, a first current curve 104, and a second current curve 106 are shown. The first voltage curve 100 has a CV of V1. The second voltage curve 102 has a CV of V2. V1 is greater than V2. The first current curve 104 has a CC of I1. The second current curve 106 has a CC of I2. I1 is greater than I2. Curves 100 and 102 are associated with a first CV and CC combination pair. Curves 104 and 106 are associated with a second CV and CC combination pair. As can be seen from the diagram, loading with V1 and I1 results in the same OCV as loading with V2 and I2, even though the values of V2 and I2 are lower and the associated loading time is longer. Area 110 under curve 104 is the same size as area 112 under curve 106.
[0029] An electric vehicle can be charged using different types of external charging stations (PICs), referred to as L1, L2, and L3 charging stations. An L1 charging station involves using a travel-ready / portable charging station and a travel cable set, and connecting to a standard 120V outlet. An L2 charging station refers to a high-voltage alternating current (HSAC) charging station that provides HSAC (e.g., 240V AC) to the electric vehicle. An L3 charging station refers to a high-voltage direct current (DCFC) fast charging station that provides high-voltage direct current (e.g., 400V or 800V) to the electric vehicle.
[0030] Traditionally, an electric vehicle controller has a fixed CV and CC combination pair that is preselected for each type of external charging station. For a given PIC station type, all PIC events terminate their charging with the same CV and CC. The same CV and CC combination pair can be used for all types L1, L2, and L3, or different CV and CC combination pairs can be used for each type of external charging station. The power output of external charging stations is increasing. Traditional external charging stations have a range of 3-7 kilowatts (kW). Modern external charging stations have a range of 19-22 kW. The higher power range allows for faster charging with higher CV and CC combination pairs.The use of higher CV and CC combination pairs for faster charging times may negatively affect cell lifespan, cell resistance and / or charging accuracy, depending on the composition and chemistry of the battery pack cells and the specific application.
[0031] The examples presented here include charging systems and circuits that modify CV and CC combination pairs in real time at the completion of charging events. A CV and CC combination pair can be selected for each charging event independently and / or dependently on the type of charging station. A CV and CC combination pair can be selected based on one or more factors, including the accuracy of the charge completion, the remaining lifespan of the rechargeable storage system (RESS), the total charging time, the cost of charging at the public station, the capabilities of the external charging station, the capabilities of internal charging, the depth of discharge, the change in RESS resistance, and so on. In some embodiments, a CV and CC combination pair is selected for each charging event based on communication between a vehicle control module and an external charging station.In other exemplary embodiments, one or more CV and CC combination pairs are selected for each charging event.
[0032] The implementations disclosed here can be applied to fully electric vehicles, BEVs, hybrid electric vehicles including PHEVs, partially or fully autonomous vehicles and other vehicle types.
[0033] The term "power source" as used here can refer to a battery pack, a battery module within a battery pack, one or more cells within a battery module of a battery pack, a battery, and / or any other rechargeable power source. A battery pack can comprise multiple battery modules, each of which can contain hundreds of cells. Therefore, a power source can comprise multiple power sources. A power source can also include a cooling circuit, sensors, switches, terminals, a control module, and so on.
[0034] Fig. Figure 2 shows a charging system 200 comprising an external charging station 202, a vehicle charging socket 204 206, an internal charging module (OBCM) 208, a vehicle integration control module (VICM) 210, and a RESS 212. The OBCM 208 includes an AD / DC converter 213 that converts HS AC to HS DC. The OBCM 208 controls the current and power on the HS-DC bus 224, a portion of which is supplied to the RESS 212 during charging. The OBCM 208 receives an AC voltage from the external charging station 202 and reports the AC voltage to the VICM 210. The OBCM 208 can regulate the voltage on the HS-DC bus 224.
[0035] The VICM 210 communicates with the external charging station 202 via a communication line 214 and controls the charging of the RESS 212 i) directly via a first high-voltage DC line 216 and a second high-voltage DC line 218, or ii) indirectly via a high-voltage AC line 220, the OBCM 208, a line 222 between the charging socket 204 and the OBCM 208, and a high-voltage DC bus 224. The communication can include determining the charging capacities of the external charging station 202 and instructions for setting CVs, CCs, and / or power outputs of the external charging station 202. The high-voltage DC line 218 can be connected to the high-voltage DC bus 224. The VICM 210 implements a CV and CC application 230 using a CV and CC combination pair table 232, which is stored in memory 234. An example of a CV and CC combination table is shown in Table 1 below. Table 1 - Examples of CV and CC combination pairs CV (V) CC (A) 4,13 3,0 4,14 5,0 4,15 10,0 4,16 20,0 4,17 30,0 4,20 50,0
[0036] Table 1 is shown as an example. The CV and CC combination pair table 232 can contain any number of CV and CC combination pairs. The CC values can be used to provide a predefined SOC percentage (e.g., 96%). The CV and CC application 230 is implemented by the VICM 210 to select CV and CC combination pairs based on the factors mentioned above. The CV and CC application 230 can implement one or more of the methods from the Fig. The RESS 212 can include one or more battery pack(s) 236, which can be connected in series and / or parallel.
[0037] The vehicle 206 further comprises an auxiliary power module (APM) 240, a heating, ventilation, and air conditioning (HVAC) system 244, a propulsion system 246, and / or other high-voltage power sources. The APM 240 can convert the high-voltage direct current on the high-voltage direct current bus 224 into low-voltage direct current and supply the low-voltage direct current to a low-voltage power source 242 (e.g., a 12 V battery, a dynamically adjustable multi-power system (MODACS), a 48 V power source, etc.). The low-voltage power source 242 can have one or more positive terminal(s) with one or more positive voltage potentials (e.g., 12 V and 48 V). The low-voltage power source 242 supplies power to low-voltage systems and / or devices 243, e.g., the vehicle's electrical system, the vehicle's electrical system, and / or the vehicle's electrical system. B. Lighting systems, infotainment systems, navigation systems, object detection and / or collision avoidance systems, seat heating and / or motors, window motors, door locks, etc.Although only a single low-voltage DC bus 245 is shown, more than one low-voltage DC bus may be present. The HVAC system 244 may include an electric coolant heater (CEH) 247 and an electric air compressor (ACEC) 249. The propulsion system 246 may include one or more motors 248 and an internal combustion engine 250, which serve to drive one or more axles and corresponding wheels of the vehicle 206.
[0038] In some embodiments, the VICM 210 modifies CV and CC combination pairs in real time. "Real time" refers to the selection of one or more CV and CC combination pair(s) before and / or during each charging session. A "charging session" can refer to each time the vehicle 206 is connected to a charging station, such as the external charging station 202. The external charging station 202 can be a type L1, L2, or L3 charging station. The VICM 210 can modify CV and CC combination pairs based on communication with the external charging station 202 and information gathered by the sensors 260. The sensors 260 can include voltage sensors, current sensors, temperature sensors, etc. The current and voltage sensors can detect current and / or voltages from consumers (e.g. consumers 243, 247, 249 etc.), the HS DC bus 224, the LS DC bus 245 etc.The current and voltage sensors can detect the current supplied to the RESS 212 and / or the voltages of the RESS 212. The current and voltage sensors can also detect the current drawn from the external charging station 202 and / or the voltage supplied by the external charging station 202.
[0039] CV and CC combination pairs can be determined using the methods of Fig. 3-4 and 7-10 must be selected before and / or during each charging cycle. This includes selecting CV and CC pairs based on one or more of the factors mentioned above. Depending on the situation and arbitration rules, one or more of the procedures can be performed for each charging cycle. The VICM 210 can perform arbitration to determine the appropriate CV and CC combination pair for a given situation. Exemplary arbitration procedures with arbitration rules are described below.
[0040] Such a procedure is used in Fig. 10 shown. The procedures of Fig. Evidence 3-4 and 7-9 comprise different criteria and logical justifications for selecting CV and CC combination pairs. The procedures may involve reducing a stored set of CV and CC combination points to a selectable subset of CV and CC combination pairs and subsequently selecting a best CV and CC combination pair from that subset.
[0041] The vehicle 206 may also include a GPS (Global Positioning System) receiver 262 and a MAP module 264. The GPS receiver 262 can provide information about the vehicle's location. The MAP module 264 can provide map information and / or charging station information, such as: charging station type information for the location of the external charging station 202; whether the charging station is a public charging station; and / or whether the charging station has time-based charging costs. The map information can also, or alternatively, indicate whether the vehicle 206 and / or the external charging station 202 is / are located in a parking garage. Based on this information, the VICM 210 can determine the type of external charging station 202. For example, if the external charging station is located in a parking garage, it can be determined to be a public charging station with time-based charging costs.Alternatively, the VICM 210 can determine the type and / or characteristics of the external charging station 202 by communicating with the external charging station and / or with another network device, including whether the external charging station 202 is a public or private charging station and / or whether the external charging station 202 has time-based charging costs.
[0042] Although the procedures of Fig. Since procedures 3-4 and 7-10 are presented as separate processes, two or more of the processes can be performed for a single loading operation. The operations of the processes can be performed iteratively. The operations can be performed by VICM 210 of the Fig. 2 will be carried out. Fig. Figure 3 shows a method for minimizing the loading time when changing a CV and CC combination pair in real time.
[0043] At 300, the VICM 210 can determine whether the vehicle 206 is plugged into the external charging station 202. If so, operation 302 is performed.
[0044] At 302, the VICM 210 can identify the external and internal charging capabilities via communication with the external charging station 202. This can include determining the voltages, currents, and / or power output capabilities of the external charging station 202 and / or the voltages, currents, and / or power input capabilities of the vehicle's internal charging system (or circuit) 206. The specified voltages, currents, and / or power levels can be displayed via the communication line 214.
[0045] For example, the VICM 210 can determine the voltage, current, and power capabilities of the external charging station 202 while the RESS 212 is actively being charged by the external charging station 202. This can include determining the AC charging capability of the external charging station 202, including: a maximum wall (or output) current capacity; a maximum wall (or output) voltage that can be measured by the OBCM 208; and a wall power capacity. The wall power capacity is the product of the wall current capacity and the wall voltage capacity. The VICM 210 can determine the DCFC capability, including the maximum external current and power of the charging station.
[0046] The VICM 210 can calculate the resulting DC current supplied to the HS DC line 218 and / or the HS DC bus 224. During AC charging, the product of available wall power and OBCM efficiency is divided by the HS DC bus voltage to provide the HS DC bus current from the OBCM 208. During DCFC, a minimum is determined from i) a maximum current from the external charging station 202 and ii) a maximum power from the external charging station 202, divided by an HS DC bus voltage.
[0047] The VICM 210 can also calculate high-voltage losses and subtract them from the DC current supplied to the high-voltage DC line 218 and / or the high-voltage DC bus 224. These losses include parasitic loads and / or other losses. Some examples of losses are those associated with air conditioners, heaters, low-voltage power consumers, etc. The losses can include current and / or power drawn by the APM 240, the HVAC system 244, and / or other high-voltage consumers 245. The losses can be actively measured in real time via the sensors 260, including the current drawn by consumers such as the CEH 247, ACEC 249, and / or other consumers. By subtracting the losses (high-voltage bus current from the OBCM 208 minus other high-voltage current draws outside the RESS 212), the high-voltage current capacity to the RESS 212 is determined.
[0048] At 304, the VICM 210 can look up and / or calculate the estimated charging power for each CV and CC combination pair, such as each CV and CC combination pair in the CV / CC table 232.
[0049] At 306, the VICM 210 can select the CV and CC combination pair with the estimated charging power that is closest to, but not greater than, the smaller of a) the power rating of the external charging station 202 and b) the power rating of the internal charging system (or circuit). Multiple CV and CC combination pairs can meet the power requirements. The power assigned to a CV and CC combination pair can be equal to the product of CV and CC. For example, two or more of the CV and CC combination pairs from Table 1 can meet the power requirements. One or more of the CV and CC combination pairs from Table 1 may not meet the power requirements. The smaller the CV and CC values in a CV and CC combination pair, the slower the charging of the RESS 212.In one embodiment, the VICM 210 can select a maximum CV and CC combination pair based on the charging capabilities of an external charging station 202 and the internal charging capabilities of the vehicle 206 to minimize the total charging time. In this way, the CV and CC combination pair with the highest values that meet the performance requirements can be selected. This also includes ensuring that the capabilities of the external charging station 202 and / or the internal charging system (or circuit), which includes the charging socket 204, lines 218 and 222, the OBCM 208, and the RESS 212, are not exceeded.
[0050] In one embodiment, the internal and external power capabilities (or limits) are determined. For each power limit and for the charge termination conditions (CV and CC combination pairs), the VICM 210 determines what a power termination would look like and then selects one that is closest to the lower of the power limits. The number of different CV and CC combination pairs that can be selected depends on the internal and external current capacities.
[0051] In one embodiment, the largest CC value that does not exceed the HS current capacity to the RESS 212 is selected. The CV corresponding to the selected CC is also selected. For example, if the HS current to the RESS 212 is 19 amperes (A), the 4.15 V and 10.0 A CV and CC combination pair from Table 1 is selected. Another example: If the HS current is 20 A, the 4.16 V and 20.0 A CV and CC combination pair from Table 1 is selected. The described selection process can also involve interpolating between CV values in Table 1 to fit a determined HS current capacity to the RESS 212 and calculating the corresponding new CV. This can be done instead of selecting one of the CV and CC combination pairs listed in Table 1. The HS current capacity to the RESS 212 can be above, between, or below the CC values in Table 1.Interpolation, estimation, and / or curve fitting can be used to calculate the corresponding CV. The CC and the CV can then be used as a new pair (or point).
[0052] At operation 308, the VICM 210 can determine whether the external charging station 202 is a DC charging station. If so, operation 310 can be performed; otherwise, operation 312 can be performed.
[0053] At 310, the VICM 210 can instruct the external charging station 202 to charge the RESS 212 based on the selected CV and CC combination pair to be provided for charging the RESS 212. The external charging station 202 controls the CV and CC provided to the charging socket 204 and the RESS 212. In one embodiment, the actual CV and CC provided by the external charging station 202 are larger than the selected CV and CC combination pair due to calculated losses. The VICM 210 can determine the actual CV and CC combination pair provided by the external charging station 202 to provide the CV and CC combination pair selected for charging the RESS 212 and report the actual CV and CC combination pair to the external charging station 202.
[0054] At 312, the VICM 210 can charge the RESS 212 based on the selected CV and CC combination pair by controlling the operation of the OBCM 208, which can regulate the CV and CC supplied to the RESS 212. The VICM 210 can determine the actual CV and CC combination pair supplied by the external charging station 202 to provide the CV and CC combination pair selected for charging the RESS 212 and report the actual CV and CC combination pair to the external charging station 202.
[0055] Fig. Figure 4 shows a RESS charging method for maximum lifetime for changing a CV and CC combination pair in real time. The VICM 210 from Fig. 2 can select a maximum CV and CC combination pair to reduce RESS degradation and thus increase the lifespan of the RESS. The CV and CC combination pair can be selected such that the lifespan of the RESS is optimized to a target lifespan. In one embodiment, RESS degradation is minimized and the RESS lifespan is maximized. In another embodiment, the CV and CC combination pair is selected such that the RESS lifespan is greater than or equal to a target RESS lifespan (e.g., 10, 12, or 15 years), which may be less than a maximum lifespan. In one embodiment, the CV and CC combination pair is selected such that the RESS lifespan is longer than (or exceeds) the target RESS lifespan.
[0056] At 400, the VICM 210 can determine whether the vehicle 206 is plugged into the external charging station 202. If so, operation 402 is performed.
[0057] At 402, the VICM 210 can identify a typical DoD of the vehicle 206 and / or a typical DoD of the vehicle 206 when used by a specific user (e.g., a specific driver) of the vehicle 206.
[0058] At 404, the VICM 210 can look up and / or calculate the estimated RESS life expectancy in years, months and / or days for each CV and CC combination pair.
[0059] At 406, the VICM 210 can select the CV and CC combination that results in a RESS lifetime that most closely matches a target RESS lifetime without being shorter than the target RESS lifetime. The CV and CC combination is selected as described above. This can also include selecting a CV and CC combination to minimize RESS degradation and thus improve (or maximize) the RESS lifetime. Alternatively, the CV and CC combination can be selected to optimize the RESS lifetime to meet or exceed a target RESS lifetime, which may be shorter than the maximum lifetime. The charging process can be performed at a slow rate to improve the accuracy of a charge-end SOC.In one embodiment, the CV and CC combination pair is selected based on the chemical composition and / or chemistry of the RESS 212 battery pack(s). Certain chemicals exhibit a longer lifespan when charged slowly. Other chemicals exhibit a longer lifespan when charged quickly. In one embodiment, the RESS 212 is charged with a constant current. In another embodiment, the RESS 212 is charged with a tapered current.
[0060] In one embodiment, a DoD value is determined that is directly related to the battery's lifespan, and a CV value is determined based on the DoD value. The corresponding CC is then selected for the chosen CV.
[0061] Fig. Figure 5 shows a representation of the battery's expected lifespan and charging time in relation to the depth of discharge (DoD). The left vertical axis (500) refers to the battery's expected lifespan in years until it reaches 75% capacity at full charge, compared to when new. The right vertical axis (502) refers to the charging time in hours. The horizontal axis (504) refers to the DoD. Curves 510, 512, and 514 relate the battery's expected lifespan for three different CVs (e.g., 4.13, 4.17, and 4.20) to the DoD. Curves 510, 512, and 514 show corresponding charging times compared to the DoD curves 514, 516, and 518.
[0062] Three ranges, 520, 522, and 524, are shown. When selecting the CV that provides the longest RESS lifespan, the lowest of the three CVs (e.g., 4.13 V) can be chosen for the second range, 522. The second CV (e.g., 4.17 V) can be chosen for the first range, 520. The third CV (e.g., 4.20 V) can be chosen for the third range, 524. As shown in Fig. As shown in Figure 5, there are two intersection points. For example, for a specific driver and vehicle, the driver may drive an average number of miles per day. The vehicle's average mileage can be determined by calculating a ratio between i) the total number of miles driven since the vehicle was new and ii) the total number of days since the vehicle was new. An average or expected range in miles at full state of charge (e.g., 96%) for the vehicle can also be estimated or determined. For example, with an average daily driving performance of 35 miles and an expected range of 100 miles, the DoD might be 0.35. Using the curves from Fig. 5. The expected RESS lifespan can be estimated. Based on the values in the diagram, the expected RESS lifespan can be 7-8 years.
[0063] The DoD can be calculated using several different methods. For example, the DoD can be calculated based on the difference between a maximum and a minimum SOC. The DoD can be determined for each of several days and then averaged to obtain an average DoD. The maximum SOC value can be the maximum SOC value for that particular day. Similarly, the minimum SOC can be the minimum SOC value for that particular day.
[0064] Battery (or RESS) lifespan can be improved by selecting a higher CV and CC combination pair, depending on the chemical composition of the power source. This can also vary depending on the application (e.g., a private vehicle with low daily mileage versus public transportation or a fleet vehicle with high daily mileage). The selection of CV and CC combination pairs is based on the natural degradation of RESS 212 over time and not on other failure mechanisms.
[0065] At operation 408, the VICM 210 can determine whether the external charging station 202 is a DC charging station. If so, operation 410 can be performed; otherwise, operation 412 can be performed.
[0066] At 410, the VICM 210 can instruct the external charging station 202 to charge the RESS 212 based on the selected CV and CC combination pair. The external charging station 202 controls the CV and CC supplied to the RESS 212.
[0067] At 412, the VICM 210 can charge the RESS 212 based on the selected CV and CC combination pair by controlling the operation of the OBCM 208, which can regulate a CV and CC that are made available to the RESS 212.
[0068] Fig. Figure 6 shows a representation of the percentage increase in cell resistance at the beginning of its service life (BOL) versus cell age in years for different usage scenarios. CV and CC combination pairs can be selected based on the change in cell resistance or the change in RESS resistance, as described below in relation to the procedure of Fig. 7 described. Fig. Figure 6 shows several curves for different scenarios, e.g., for a daily driver, a regular driver, a vehicle driven in a hot climate, a vehicle driven in a cold climate, drivers and vehicles with different DoDs, driving patterns, etc. As shown Fig. As can be seen in Figure 6, the mean resistance of this cell population increases along with the resistance variations within this population as a given cell population ages across multiple vehicles. The older the cell, the more unpredictable its performance becomes, and the greater its resistance. The higher the resistance, the lower the cell's peak full voltage and the lower its OCV value. To compensate for the effect of the higher resistance and reduced SOC accuracy, the CC can be reduced. For example, if 96% SOC ±1% is the target and the resistance has increased, the CC can be tapered to lower the CV and CC combination pair. In one embodiment, a lower CC value can be chosen as the cell (or RESS) ages to improve charge termination accuracy.
[0069] Equations 1-4 posit an OCV (V OC ) and a terminal voltage VT in relation. The terminal voltage V T The terminal voltage V varies depending on cell resistance, voltage hysteresis, diffusion voltage, and other effects (chemical properties). T of the RESS 212 Fig. 2 is the CV before a full charge. V OC is the open-circuit voltage of the RESS 212 after it has been at rest for a while. I is the current to the RESS 212 and is the constant current (CC) before the charging process is complete. R O V is the known BOL resistance of the RESS 212, and ΔR refers to the unknown increase in resistance due to aging. Other stands for other effects, such as stress hysteresis, diffusion stress and the double layer effect. VOC=VT−I∗RO−I∗ΔR−VOther VT=VOC+I∗R+VOther VOC=VT−I∗(RO+ΔR)−VOther VOC=VT−I∗RO−I+ΔR−VOther
[0070] The larger the value of ΔR at a fixed V T The more... the more... the more... the goal V OCThe target value was undershot. With a higher expected uncertainty in ΔR or a high estimated value of ΔR, the error in the target value V may be lower. OC by minimizing / (e.g., by selecting a lower CV and CC combination point). The part I ∗ ΔR of equation 1 is associated with the increase in resistance of the RESS 212 with increasing age of the RESS 212.
[0071] Fig. Figure 7 shows a method for lowering a CV and CC combination point in real time as a function of the RESS resistance growth and uncertainty in increasing the charge completion SOC accuracy.
[0072] At 700, the VICM 210 can determine whether the vehicle 206 is plugged into the external charging station 202. If so, operation 702 is performed.
[0073] At 702, the VICM 210 can estimate the RESS resistance uncertainty and / or growth based on the mileage displayed on a vehicle's odometer and / or based on the calendar lifetime of the vehicle and / or the calendar lifetime (time since new purchase and / or first use) of the RESS 212 battery pack(s). The RESS resistance uncertainty and / or growth can be visualized using a graph similar to the one in Fig. 6, a lookup table relating the RESS resistance uncertainty and / or growth with the mileage and / or lifespan of the vehicle and / or the RESS, and / or one or more equations relating the RESS resistance uncertainty and / or growth with the mileage and / or lifespan of the vehicle and / or the RESS, can be estimated. At 704, the VICM 210 can look up and / or calculate the estimated charge completion SOC uncertainty for each CV and CC combination pair. The procedure of Fig. 8 can be performed up to the estimated charge completion SOC uncertainty.
[0074] At 706, the VICM 210 can select a CV and CC combination pair that results in a charge completion SOC uncertainty that most closely approximates a charge completion SOC target uncertainty without exceeding the charge completion SOC target uncertainty. See the procedure of Fig. 8. For example, the resulting charge completion SOC uncertainty can be within 0.5% of the charge completion SOC target uncertainty without exceeding the charge completion SOC target uncertainty.
[0075] At operation 708, the VICM 210 can determine whether the external charging station 202 is a DC charging station. If so, operation 710 can be performed; otherwise, operation 712 can be performed.
[0076] At 710, the VICM 210 can instruct the external charging station 202 to charge the RESS 212 based on the selected CV and CC combination pair. The external charging station 202 controls the CV and CC supplied to the RESS 212.
[0077] At 712, the VICM 210 can charge the RESS 212 based on the selected CV and CC combination pair by controlling the operation of the OBCM 208, which can regulate a CV and CC that are made available to the RESS 212.
[0078] Fig. Figure 8 shows a method for adjusting a CV and CC combination pair based on changes in the RESS resistance and the state of charge (SOC) error.
[0079] At 800, the VICM 210 can estimate the real-time resistance of the RESS 212. At 802, based on the real-time resistance of the RESS 212 and its initial resistance when new, the VICM 210 can estimate the change in resistance over the lifetime of the cells in the RESS 212 battery pack(s). The real-time resistance can be measured and / or determined based on the outputs of one or more sensors 260. One or more of the sensors 260 can be used to determine parameters of the RESS 212, from which the real-time resistance can be estimated.
[0080] At 804, the VICM 210 can set a counter to 1. At 806, the VICM 210 can estimate an OCV based on a target OCV and the product of current and resistance change of the RESS 212. At 808, the VICM 210 can estimate a SOC based on the estimated OCV. This can be done, for example, using a lookup table that relates estimated OCV values to SOC values.
[0081] At 810, the VICM 210 can determine a SOC error based on the estimated SOC and a target SOC. The SOC error can be equal to the difference between the target SOC and the estimated SOC. At 812, the VICM 210 can store a SOC error for a corresponding i-th CV and CC combination pair, where i is an index value relating to a specific CV and CC combination pair.
[0082] Operation 814 allows the VICM 210 to determine if the counter value equals the total number of CV and CC combination pairs. If not, operation 816 is performed and the counter is incremented. If so, operation 818 can be performed. Operation 818 allows the VICM 210 to select the CV and CC combination pair with the highest corresponding power output that exhibits a state-of-charge error within a specified error range (e.g., 0.5%).
[0083] Fig. Figure 9 shows a method for changing a CV and CC combination pair in real time depending on whether an external charger is a public charger with charging time-based costs.
[0084] At 900, the VICM 210 can determine whether the vehicle 206 is plugged into the external charging station 202. If so, operation 902 is performed.
[0085] At 902, the VICM 210 can determine whether the external charging station 202 is a public station that charges a time-based fee for charging the RESS 212. The VICM 210 of the Fig. 2 can determine whether the external charging station 202 is a public or private charging station. This can be determined based on the location of the vehicle 206 and / or communication with the external charging station 202. If it is not public and / or no time-based charge applies for billing, the procedure can be terminated; otherwise, operation 904 can be performed.
[0086] At 904, the VICM 210, as described above, can identify the external and internal charging capabilities via communication with the external charging station 202. The external charging station 202 can display its charging capabilities to the VICM 210, including the maximum charging voltage, maximum charging current, and / or maximum output power. The VICM 210 can determine the charging capabilities of the internal charging system (or circuit), including the maximum charging voltage, maximum charging current, and / or maximum received power.
[0087] At 906, the VICM 210 can look up and / or calculate an estimated charging power for each CV and CC combination pair.
[0088] At 908, the VICM 210 can select a CV and CC combination pair with an estimated charging power that is closest to, but not greater than, the smaller of a) the power capacity of the external charging station 202 and b) the power capacity of the internal charging system (or circuit).
[0089] At operation 910, the VICM 210 can determine whether the external charging station 202 is a DC charging station. If so, operation 912 can be performed; otherwise, operation 914 can be performed.
[0090] At 912, the VICM 210 can instruct the external charging station 202 to charge the RESS 212 based on the selected CV and CC combination pair. The external charging station 202 controls the CV and CC supplied to the RESS 212.
[0091] At 914, the VICM 210 can charge the RESS 212 based on the selected CV and CC combination pair by controlling the operation of the OBCM 208, which can regulate a CV and CC that are made available to the RESS 212.
[0092] By performing operations 904, 906, 908, 910, 912, and 914 in response to the fact that external charging station 202 is a public charging station with associated charging costs, the charging time is minimized to minimize the cost of charging the RESS 212. To minimize charging costs, the charging time can be minimized by selecting a CV and CC combination pair for fast charging.
[0093] Fig. Figure 10 shows a real-time arbitration procedure for adjusting a CV and CC combination pair. For example, the CV and CC combination pair that provides the most accurate SOC value may not provide the fastest charging time and / or be the best CV and CC combination pair for maximizing RESS lifetime. The arbitration takes place between the application of the RESS charging procedure for maximum lifetime according to Fig. 4 and the method for minimizing the charging time of Fig. 3.
[0094] At 1000, the VICM 210 can determine whether the vehicle is plugged into a charging station. If so, operation 1002 can be performed.
[0095] At 1002, the VICM 210 can filter out discrete CV and CC combination pairs from a complete list (or table) of possible pairs that do not meet the charge termination accuracy requirements. The charge termination accuracy requirements are a function of the RESS resistance growth (or the change in RESS resistance over time). Higher CV and CC combination pairs and higher RESS resistance growth / uncertainty result in greater charge termination SOC inaccuracy.
[0096] At operation 1004, the VICM 210 can determine whether the external charging station 202 is a public station. If not, operation 1006 can be performed; otherwise, operation 1008 can be performed.
[0097] At version 1006, the VICM 210 can implement the RESS charging method for maximum lifetime to select a CV and CC combination pair that maximizes the lifetime of the RESS (also referred to as longevity) and minimizes RESS degradation. At version 1008, the VICM 210 can implement the charging time minimization method to select a CV and CC combination pair that minimizes the charging time.
[0098] As another example of arbitration, the VICM 210 can start with a specific number X of discrete CV and CC combination pairs. The VICM 210 can then identify a typical user DoD and RESS resistance / uncertainty. The VICM 210 can then filter out the points that do not meet a lifetime requirement, which is a function of the DoD. An example of a lifetime requirement is 10 years and 100,000 miles for a RESS. The VICM 210 can then filter out CV and CC combination pairs (or points) that do not meet the SOC accuracy requirements. The VICM 210 can then select one CV and CC combination pair from the remaining CV and CC combination pairs to minimize the load time.
[0099] The examples described above, which include real-time modification and selection of CV and CC combination pairs for charge completion, reduce and / or minimize charging time, reduce and / or minimize RESS capacity degradation associated with charging, increase charge completion SOC accuracy, reduce user costs for public charging of a RESS, and provide a better ability to meet users' daily charging needs, including targeting a user-specific time for full charging.
[0100] The foregoing description serves only for illustration and is in no way intended to limit the disclosure, its application, or use. The comprehensive teachings of the disclosure can be implemented in a multitude of forms. Although this disclosure includes particular examples, the true scope of the disclosure should not be so restricted, since other modifications will become apparent upon study of the drawings, the description, and the following claims. It is understood that one or more steps within a process may be carried out in a different order (or simultaneously) without altering the principles of the present disclosure.Although each of the embodiments described above has certain features, one or more of these features described in relation to any embodiment of the disclosure may also be implemented in any other embodiment and / or combined with features of any other embodiment, even if this combination is not expressly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments remain within the scope of this disclosure.
[0101] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "intervening," "coupled," "adjacent," "next to," "above," "below," and "arranged." Unless a relationship between a first and a second element is explicitly described as "direct" in the above disclosure, this relationship may be a direct relationship in which no other intervening elements exist between the first and the second element, or it may be an indirect relationship in which one or more intervening elements (either spatial or functional) exist between the first and the second element.As used herein, the phrase “at least one of A, B and C” should be understood as a logical (A OR B OR C) using a non-exclusive logical OR, and not as “at least one of A, at least one of B and at least one of C”.
[0102] In the figures, the direction of an arrow, as indicated by the arrowhead, generally shows the flow of information (e.g., data or instructions) that is relevant to the illustration. For example, if Element A and Element B exchange a variety of information, but the information transmitted from Element A to Element B is relevant to the illustration, the arrow may point from Element A to Element B. This unidirectional arrow does not mean that no other information is transmitted from Element B to Element A. Furthermore, when information is sent from Element A to Element B, Element B may request the information from Element A or acknowledge its receipt.
[0103] In this application, including the definitions below, the term "module" or the term "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a (shared, dedicated, or grouped) processor circuit that executes code; a (shared, dedicated, or grouped) memory circuit that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above components, for example, in a system-on-a-chip.
[0104] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the internet, a wide area network (WAN), or combinations thereof. The functionality of any module of this disclosure may be distributed among multiple modules connected via interface circuits. Multiple modules may, for example, enable load balancing. In another example, a server module (also known as a remote or cloud module) may perform some functions on behalf of a client module.
[0105] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "common processor circuit" refers to a single processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" refers to a processor circuit that, in combination with other processor circuits, executes some or all of the code from one or more modules. The term "multiple processor circuits" refers to multiple processor circuits on individual dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above.The term "shared memory circuit" refers to a single memory circuit that stores some or all of the code from multiple modules. The term "group memory circuit" refers to a memory circuit that, in combination with additional memory, stores some or all of the code from one or more modules.
[0106] The term "memory circuit" is a subset of the term "computer-readable medium." The term "computer-readable medium," as used here, does not include transient electrical or electromagnetic signals propagating through a medium (e.g., on a carrier wave); the term "computer-readable medium" can therefore be considered material and non-transient. Non-restrictive examples of a non-transient, material, computer-readable medium include non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random-access memory circuit or a dynamic random-access memory circuit), magnetic storage media (such as analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).
[0107] The devices and methods described in this application can be implemented in part or in full by a specialized computer created by configuring a general-purpose computer to perform one or more specific functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a qualified technician or programmer.
[0108] Computer programs comprise processor-executable instructions stored on at least one non-transient, tangible, machine-readable medium. Computer programs may also contain or rely on stored data. They may include a basic input / output system (BIOS) that interacts with the hardware of the specialized computer, device drivers that interact with specific devices of the specialized computer, one or more operating systems, user applications, background services, background applications, and so on.
[0109] The computer programs may include: (i) descriptive text to be parsed, e.g. B. HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. The source code can be written in the syntax of languages such as C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.
Claims
[1] Charging system for an electric vehicle, the charging system comprising: a memory configured to store a plurality of terminal voltage (CV) and cut-off current (CC) combination pairs; a charging socket configured to be connected to an external charging station; and an internal charging circuit comprising a high-voltage direct current bus connected to a rechargeable energy storage system, and a control module configured to communicate with the external charging station and determine the charging capabilities of the external charging station and the internal charging circuit, select one of the plurality of CV and CC combination pairs based on the charging capabilities of the external charging station and the internal charging circuit, and initiate charging of the rechargeable energy storage system based on the selected one of the plurality of CV and CC combination pairs. [2] The charging system of claim 1, further comprising an internal charging module configured to: converts an AC voltage received from the external charging station via the charging socket into a DC voltage and supplies the DC voltage to the high-voltage DC bus; displays the AC voltage to the control module; and receives an instruction from the control module to convert the AC voltage to the CV of one of the plurality of CV and CC combination pairs for charging the rechargeable energy storage system. [3] The charging system of claim 1, wherein the control module is configured to: looks up or calculates an estimated charging power value for each of at least some of the plurality of CV and CC combination pairs to provide a plurality of charging power values; and based on the plurality of charging power values, selecting the one of the plurality of CV and CC combination pairs at which the estimated charging power is closest to, but not greater than, a smaller value of a) a power capacity of the external charging station and b) a power capacity of the internal charging circuit. [4] The charging system of claim 1, wherein the control module is configured to: a depth of discharge is determined; looks up or calculates an estimated life expectancy of the rechargeable energy storage system for each of at least some of the plurality of CV and CC combination pairs; and selecting, based on the depth of discharge, the one of the plurality of CV and CC combination pairs that results in a life expectancy of the rechargeable energy storage system that is closest to a target life expectancy without being shorter than the target life expectancy. [5] The charging system of claim 1, wherein the control module is configured to: estimates the resistance uncertainty and / or resistance growth of the rechargeable energy storage system; based on the resistance uncertainty and / or the resistance growth, look up or calculate the estimated charge completion state of charge uncertainty of the rechargeable energy storage system for each of at least some of the plurality of CV and CC combination pairs; and based on the estimated charge completion state of charge uncertainties, selecting the one of the plurality of CV and CC combination pairs that results in a charge completion state of charge uncertainty that is closest to a charge completion state of charge target uncertainty without exceeding the charge completion state of charge target uncertainty. [6] The charging system of claim 1, wherein the control module is configured to: for each of at least some of the plurality of CV and CC combination pairs, estimates a change in the resistance of the rechargeable energy storage system, estimates an open circuit voltage based on the change in resistance and the current supplied to the rechargeable energy storage system, estimates the state of charge based on the estimated open circuit voltage, and determines a state of charge error based on the estimated state of charge and a target state of charge; and selects the one from the plurality of CV and CC combination pairs that has the highest corresponding power and a state of charge error within a specified error range. [7] The charging system of claim 1, wherein the control module is configured to: determines whether the external charging station is a public station; determines whether the external charging station has time-based charging costs; in response to determining that the external charging station is a public station and that it has a time-based cost for charging, looks up or calculates estimated charging power values for each of at least some of the plurality of CV and CC combination pairs to provide a plurality of charging power values; and based on the plurality of charging power values, selecting the one of the plurality of CV and CC combination pairs at which the estimated charging power is closest to, but not greater than, a smaller value of a) a power capacity of the external charging station and b) a power capacity of the internal charging circuit. [8] The charging system of claim 1, wherein the control module is configured to: determines whether the external charging station is a public station; in response to determining that the external charging station is a public station, implements a charging time minimization method to select one of the plurality of CV and CC combination pairs; and in response to determining that the external charging station is not a public station, performs a maximum life charging procedure to select one of the plurality of CV and CC combination pairs. [9] The charging system of claim 1, wherein the control module is configured to: a depth of discharge is determined; determines a resistance uncertainty or resistance growth of the rechargeable energy storage system; based on the depth of discharge, filtering out some of the plurality of CV and CC combination pairs that do not meet a lifetime requirement for the rechargeable energy storage system to provide a first resulting set of CV and CC combination pairs; filters out some of the first resulting set of CV and CC combination pairs that do not meet a state of charge accuracy requirement to provide a second resulting set of CV and CC combination pairs; and a method for minimizing the loading time is implemented to select the one of the plurality of CV and CC combination pairs from the second resulting set of CV and CC combination pairs. [10] The charging system of claim 1, wherein the control module is configured to: determines whether the external charging station is a DC charging station or an AC charging station; in response to the external charging station being a DC charging station, instructing the external charging station to charge the rechargeable energy storage system based on the selected CV and CC combination pair; and in response to the external charging station being an AC charging station, to charge the rechargeable energy storage system based on the selected CV and CC combination pair.