Abstract:
An electric charging system for a battery pack of an electric vehicle, including a charging station electrically coupled to the battery pack, the charging station transferring charging energy to the battery pack at a maximum fast charge rate in a first operational mode and transferring charging energy to the battery pack at a slower charge rate in a second operational mode; a data collection system acquiring a set of data indicating a state of charge (SOC) of the battery pack and one or more desired charge optimization parameters; and a station control, responsive to the set of data and to the desired charge optimization parameters, automatically establishing a charging profile for the battery pack to assert a control signal and operate the charging station in the second operational mode whenever the charging station is able to transfer sufficient energy to the battery pack at the slower charge rate to meet an SOC target and a charge completion time target, otherwise asserting the control signal and operate the charging station in the first operational mode.

Description:
The present application is a divisional of U.S. patent application Ser. No. 13/475,396, filed May 18, 2012, the disclosure of each of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to charge rate optimization, and more specifically, but not exclusively, to implementation of a charge rate at less than a maximum fast rate based upon user requirements for optimization of secondary considerations of economy, battery life, or the like when primary considerations of SOC and charge completion time targets are not adversely impacted by a slower charge rate. 
     Charging high performance battery packs implicate many nuanced considerations and subtleties in order to maximize sometimes competing goals of maximum battery pack lifetime, performance, and availability. For user convenience, fast chargers have been designed and implemented for personal and public charging stations. These chargers are designed to quickly restore a user&#39;s access to their electric vehicle. This enhanced charging speed comes at a potential cost of degrading battery life. 
     For many electric vehicle (EV) users, recharging their EV as quickly as possible is considered very important, and these users select the fastest charging option whenever possible even when a slower charging option may be more economical, more efficient, and/or better for the battery pack. What is needed is a system and method providing fast charge optimization based upon user need. 
     BRIEF SUMMARY OF THE INVENTION 
     Disclosed is a system and method providing fast charge optimization based upon user need. Manually or automatically determined or inferred actual user need is used to optimize charging rate when the user does not otherwise require the full charging rate over the entire charging period (the maximum fast charge is always available). 
     The following summary of the invention is provided to facilitate an understanding of some of technical features related to fast charge optimization, and is not intended to be a full description of the present invention. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole. The present invention is applicable to other charging scenarios in addition public charging of electric. 
     An electric charging system for an energy storage system includes a charging station electrically coupled to the energy storage system, the charging station transferring charging energy to the energy storage system at a maximum fast charge rate in a first operational mode and transferring charging energy to the energy storage system at a slower charge rate in a second operational mode, the modes responsive to a control signal; a data collection system acquiring a set of data indicating a state of charge (SOC) of the energy storage system and one or more desired charge optimization parameters; and a station control, responsive to the set of data and to the desired charge optimization parameters, automatically establishing a charging profile for the energy storage system to assert the control signal and operate the charging station in the second operational mode whenever the charging station is able to transfer sufficient energy to the energy storage system at the slower charge rate to meet an SOC target and a charge completion time target, otherwise asserting the control signal and operate the charging station in the first operational mode. 
     A computer-implemented charging method for an energy storage system including a) collecting data to answer an optimization query designed to establish an SOC target and a charge completion time target for the energy storage system, a primary consideration for charging the energy storage system including satisfaction of the SOC target and the charge completion target; b) determining using a microprocessor system whether a satisfaction of the primary consideration requires a maximum fast charge rate from a charging station coupled to the energy storage system; c) charging the energy storage system at the maximum fast charge rate when required to attempt to satisfy the primary consideration; otherwise d) charging the energy storage system at a secondary charge rate slower than the fast charge rate to satisfy the primary consideration when satisfying the primary consideration does not require the maximum fast charge rate, the secondary charge rate responsive to one or more secondary considerations including one or more of an improved economical charging cycle and an improved lifetime for the energy storage system. 
     Other features, benefits, and advantages of the present invention will be apparent upon a review of the present disclosure, including the specification, drawings, and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention. 
         FIG. 1  illustrates an enhanced charging station having user-need optimization features; and 
         FIG. 2  illustrates a flowchart for an enhanced charging process. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention provide a system and method providing fast charge optimization based upon user need. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. 
     Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. 
       FIG. 1  illustrates an enhanced charging system  100  including an optimized fast charging station  105  having user-need optimization features. Fast charging station  105  supplies electrical energy for recharging energy storage systems (e.g., high-performance battery packs used in electric vehicles, plug-in hybrids electric-gasoline vehicles, semi-static and mobile electrical units, and the like). This electrical energy is converted and appropriately processed for desired electrical characteristics from an energy/power source  110  (e.g., electrical grid, network AC line power, battery source, or the like) that sets a maximum charge rate for charging station  105 . The present invention is applicable to any charging station  105 , whether it uses a constant power, constant current, constant voltage, algorithmic charging curve, or other charging profile providing a range of charge rates and irrespective of the nature of power source  110 . 
     As noted above, charging station  105  may be used for many different systems and provide differing amounts of charging energy, whether it is a level 1, level 2, or level 3 charger, or other configuration not presently implemented, and the present invention may be adapted appropriately. To simplify the discussion and to aid in understanding aspects of the invention, a scenario is described in which charging station  105  includes a level 3 fast charger using electrical grid energy for power source  110  to charge an electric vehicle  115 . 
     Enhanced charging system  100  includes a station control  125  which oversees the charging and implements appropriate optimization profiles based upon actual needs of user  120 . A communications network  130  is shown interconnecting selected components of enhanced charging system  100 . Communications network  130  may be implemented in a wired mode, a wireless mode, or a combination of wired and wireless modes. There may be multiple different implementations of wired and wireless technologies all employed by enhanced charging system  100 , some of which are further explained below. Not all aspects of enhanced charging system  100  will include the same components or provide the same interconnections. Information and data flows between the interconnected selected components is appropriate to the degree and nature of the optimizations desired and implemented. 
     Enhanced charging system  100  additionally includes a user interface  135  and a generic function referred to herein as vehicle enhancement  140 . User interface  135  may be any appropriate input/output system enabling user  120  to either directly enter charge optimization data, a fast charging profile, or other explicit or inferred data from which an optimized charging profile for user  120  may be selected or constructed. User interface  135  may be integrated into and/or distributed over one or more of the other components of enhanced charging system  100 . Vehicle enhancement  140  includes features and systems that may be used in the building and implementation of a desired optimization profile. 
     For example, for some cell chemistries used in the energy storage system of certain high-performance electric vehicles  115 , frequent and extended uses of fast charging may adversely impact useful lifetime performance of the energy storage system. For some of these cell chemistries and charging implementations, some vehicle enhancement (e.g., environmental control of a system or component) of electric vehicle  115  will help counter some of the adverse effects of fast charging. One such environmental control is to ensure that the energy storage system is at an optimum temperature before initiation of the optimized charging profile being implemented. In such cases vehicle enhancement  140  includes a temperature control (typically a warmer) for the battery pack serving as the propulsion energy storage system of electric vehicle  115 . Other implementations may employ alternative or additional vehicle enhancement systems appropriate for those applications and design considerations. 
     Station control  125  collects available data from components of enhanced charging system  100  to establish an optimized charging profile that transfers charging energy/power from charging station  105  to electric vehicle  115 . This optimized charging profile may be dynamic or static and it may be explicitly set by user  120  (e.g., using user interface  135 ) or inferred from other available data. For the preferred implementation, the optimized charging profile primarily ensures that user  120  meets their needs for use of electric vehicle  115 . Secondarily other considerations may be optimized as long as these primary needs are satisfied. 
     The primary consideration is set by station control  125  determining when user  120  needs electric vehicle  115  to be available and what is the range requirement for electric vehicle  115  when user  120  expects to use electric vehicle  115 . There are many different ways station control  125  may establish or infer answers to these questions, the answers being used to build the charge optimization profile. 
     Typically, the answer to the optimization question to user  120  of “when do you need it and how far do you need to go?” is “it is needed as soon as possible and I need to go as far as possible.” This may be expressed in such general terms or in explicit state of charge (SOC) terms such as 80 miles range in one hour from now. In these cases, charging station  105  provides maximum available fast charge rate to meet the primary need of user  120 . However in other cases, the answer to the optimization question is something else and in these instances enhanced charging system  100  offers many advantages without interfering with satisfaction of primary considerations in the typical case. 
     In some cases, user  120  may not be aware or cognizant that less than a maximum fast charge will satisfy their current optimization question. The user may know that they need to be in City X three hours from now, but not realize that the necessary SOC for that range could be achieved with something other than a maximum fast charge. For situations when a “medium charge rate” scenario produces a valid charging profile that meets the user&#39;s primary needs, enhanced charging system  100  is then able to implement the charging profile optimized to include secondary considerations. These secondary considerations may be established by user  120 , set by an owner/operator of charging station  105 , or some combination. Some representative secondary considerations include a battery life conservation mode, an economical mode, a charger queue status (e.g., whether other customers are waiting to use the charger), a charger status, or other modes. Enabling station control  125  to factor in secondary considerations provides options that would not otherwise be available. 
     Enhanced charging system  100  is more intelligent and uses available resources more optimally. For example, when user  120  requests (explicitly or implicitly) 80% SOC two hours from the initiation of charging, station control  125  determines, for this particular charging use, an optimal combination of vehicle enhancement (e.g., pre-heating of the battery pack) and lower charge rate to meet the user primary need. This eliminates/minimizes any risk of possible battery life degradation due to this charging cycle. Alternatively, when the secondary consideration is a more economical mode, station control  125  could opt-out of using energy for battery pack pre-heating. 
     In some scenarios, it is possible that user  120  could be charged based upon some tiered pricing structure for use of high-performance charging (e.g., fee based upon charging measured in miles/minute or kWh/minute or the like). For charging scenarios where user  120  does not require the highest-priced charging rate, automatic use of a lower priced, slower charge rate advantages user  120 , particularly for an economical mode secondary consideration. Implementations of the present invention may be adapted for different sets of secondary considerations. 
     The more data that is available to station control  125 , the better enhanced charging system  100  is able to define and implement an appropriate optimization charging profile. Preferably station control  125  takes into account how much charge energy is currently stored in electric vehicle  115  and understands other charging parameters of enhanced charging system  100  to be able to estimate charge times and expected SOC levels accurately in order to meet the primary needs of user  120 . This data may be made available from on-vehicle sensors, on-vehicle management systems, or the like. 
     Station control  125  collects any available necessary or desirable data using communications network  130  to access charging station  105 , electric vehicle  115 , user  120 , and/or user interface  135 . Station control  125  may, in some implementations, not only obtain key charging parameters (e.g., current SOC) from electric vehicle  115 , but may access on-board or cloud-based electronic trip planning/navigation systems to automatically help establish answers to the optimization question (e.g., how far away is the next stop for user  120  and is there a scheduled time for departure/arrival). Station control  125  has access to the available data to formulate many different questions/responses that explicitly define, or allow intelligent inference of, an optimized charging profile that meets desired primary and selected secondary considerations. 
     The optimized charging profile may be static, dynamic, or some combination. A static profile is one that is set at the initiation of the charging cycle. It will stop when completed, or it may be interrupted, such as to terminate charging early or to redefine the charging profile. Enhanced charging system  100  enables dynamic charging profiles to be used as well. For example, user  120  may communicate with station control  125  periodically using communications network  130  (e.g., user  120  may employ a portable electronic device (e.g., smartphone or the like) operating a software process that communicates wirelessly with station control  125  and/or electric vehicle  115 ). Changes to the optimization question (e.g., lunch is running longer than anticipated and more time is available for charging or the destination is changed so less range is required) result in automatic adjustments to the optimization profile when communicated to station control  125 , such as by entering updated data from the portable electronic device carried by user  120 . 
     In some cases charging station  105  may be able to provide variable rate charging to multiple electric vehicles at the same time. Charging station  105  would be able to dynamically allocate different charging rates to different electric vehicles based upon an aggregation of priority and optimization questions of several users at one time. In some cases charging station  105  would not be able to provide all users with full fast charging at the same time and enhanced charging system  100  would dynamically apportion charging energy transfer rates among the several electric vehicles. 
     Enhanced charging system  100  offers additional options to the users of the several electric vehicles and to the owner/operator of charging station  105 . A simple priority system would have a first electric vehicle (vehicle A) arriving at charging station  105  first receive priority over a second electric vehicle (vehicle B) arriving later. However based upon optimization questions, it may be that vehicle B has need of a full fast charge and vehicle A could use a medium charge and still meet desired SOC and departure targets for both users. Enhanced charging system  100  is able to reallocate resources of charging station  105  to meet both user needs. 
     There are other options as well. In the case that all needs of all concurrent users of charging station  105  cannot be met, station control  125  may issue offers to first-in-time higher priority users requesting changes to their travel plans (e.g., delay departure by some predetermined time) in exchange for appropriate compensation. Station control  125  is able to intelligently make offers as it understands all current charging expectations and scheduled charge completion times. For example, user A may be offered a discount on her charging costs if she agrees to delay her departure 15 minutes to accommodate user B&#39;s need for a maximum fast charge. When agreed to, the users are notified of the new charging schedules, with both users satisfied of the outcome. In some implementations, concurrent users of charging station  105  may participate in a real-time auction for charging rate in cases where demand exceeds capacity. Thus enhanced charging system  100  may establish a dynamic price for different tiers of charging speed to accommodate users with urgent needs. 
     In some cases, it may meet overall optimization goals for charging station  105  to consider that a newer arrival may already have the battery pack at or near an optimum temperature for charging. Giving this user charging priority may help meet other implemented secondary considerations of enhanced charging system  100 . This may be advantageous as an earlier user&#39;s requirement for a pre-heating phase is not affected by delaying initiation of charging and thus will consume the same amount of energy for warming and charging irrespective of whether charging is performed “now” as opposed to “later.” As long as the user&#39;s primary needs are otherwise met, changing charging order or priority does not adversely impact the earlier user. In this scenario the overall energy used is less when considering energy consumption of both drivers than would be the case of charging performed based strictly on arrival order. 
       FIG. 2  illustrates a flowchart for an enhanced charging process  200 , such as may be implemented by enhanced charging system  100  shown in  FIG. 1 . Process  200  includes steps  205 - 235  and begins at step  205  to collect data to answer some version of the optimization question to the user: “When do you need your electric vehicle to be ready and how far do you need to go?” Process  200  receives data from the electric vehicle and/or the user to explicitly answer this question, or may infer the answer from other available data, and sets this as the primary consideration. Based upon the collected data, process  200  next at step  210  establishes an answer to a first question of whether a maximum/fast charge is required to best meet the primary consideration. When the answer to that question is “YES” process  200  branches to step  215  to initiate the required fast charge. When the answer to the question of step  210  is “NO” then process  200  branches to step  220  to build an optimization profile that includes one or more secondary considerations. These secondary considerations may include an “economical” mode or a “best battery life” mode, a combination of these modes or some mode altogether different. The mode may be set or influenced by the user or owner/operator of the charging station. After the optimization profile is built at step  220 , process  200  advances to step  225  to initiate charging using the optimization profile which is likely to be, but not necessarily, different from the maximum fast charge of step  215 . 
     After both step  215  and step  225 , process  200  makes a second test at step  230  to determine whether there have been any changes that could affect the charging rate currently being applied (i.e., a change to the primary or secondary considerations used by process  200 ). These changes may be explicit changes or may be implicit in other factors affecting enhanced charging system  100 . Explicit changes include an express change to departure time or destination that is communicated to station control  125 . Implicit changes include secondary factors that implicate changes to the departure time or destination, affect charge rate, and/or affect vehicle enhancement. For example, before charging is actually initiated using an existing optimization profile, temperature data currently indicates that there are now benefits to pre-heating the energy storage system when there had been no previous advantage to pre-heating during a previous test (e.g., the energy storage system has cooled). When there are no changes at step  230 , process  200  implements step  235  and continues charging as determined by step  215  or step  225 . Process  200  continues to loop from step  235  to the test at step  230  while charging in case important changes are made or detected. 
     When the test at step  230  indicates that there are changes that could affect the answer to the optimization question, process  200  returns to step  205  to collect new data as necessary or appropriate. Process  200  continues until charging is terminated. 
     The system and methods above has been described in general terms as an aid to understanding details of preferred embodiments of the present invention. In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the present invention. It is anticipated that many implementations of the present invention include fast level 3 chargers for electric vehicles, such as incorporated into public charging stations. The present invention may be implemented in other contexts as well. One of the many advantages of the disclosed implementations of the present invention is that the user is not always tasked with understanding the many nuances and most current subtleties in implementing effective charging profiles to meet secondary considerations. As noted, there are nuances to building and implementing an effective charging profile to optimally enhancing battery life for any particular energy storage system. By using the systems and methods disclosed herein, the user does not need to learn and understand these evolving nuances. The user may be goal focused, and the systems and methods may optimally implement the charging profile(s) that best meet those goals. As the nuances evolve, the systems and methods are easily upgraded to implement the appropriate requirements, all without detailed involvement from the users. One or more components of the system and method are implemented using microprocessors executing instructions accessed from memory, these instructions available in software or firmware. 
     Some features and benefits of the present invention are realized in such modes and are not required in every case. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention. 
     Reference throughout this specification to “one embodiment”, “an embodiment”, or “a specific embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, respective appearances of the phrases “in one embodiment”, “in an embodiment”, or “in a specific embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention. 
     It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. 
     Additionally, any signal arrows in the drawings/Figures should be considered only as exemplary, and not limiting, unless otherwise specifically noted. Furthermore, the term “or” as used herein is generally intended to mean “and/or” unless otherwise indicated. Combinations of components or steps will also be considered as being noted, where terminology is foreseen as rendering the ability to separate or combine is unclear. 
     As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. 
     The foregoing description of illustrated embodiments of the present invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention. 
     Thus, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention is to be determined solely by the appended claims.