WO2023158427A1

WO2023158427A1 - Electrical storage for battery electric vehicle

Info

Publication number: WO2023158427A1
Application number: PCT/US2022/016794
Authority: WO
Inventors: Chad Burchett
Original assignee: Volvo Truck Corporation
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2023-08-24

Abstract

An electrical storage system and method is described. The system may comprise a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by an external high voltage power source, and an ultra-capacitor pack configured to store electric energy received from the external high voltage power source. The ultra-capacitor pack is configured to supply the electric energy stored in the ultra-capacitor pack to a vehicle battery of a battery electric vehicle when electrically connected to the vehicle battery. The high voltage battery pack is configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

Description

ELECTRICAL STORAGE FOR BATTERY ELECTRIC VEHICLE

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate generally to an electrical storage system and method for a battery electric vehicle, and more specifically, to an electrical storage system onboard a battery electric vehicle for a rapid charging and a corresponding method thereof.

BACKGROUND

[0002] Battery Electric Vehicles (BEVs) are limited in driving range due to the limited amount of electric energy stored in their onboard battery packs. The amount of electric energy stored in the battery packs is limited due in part to the storage capacity of the battery packs, and to insufficient time to fully charge the battery packs. When a BEV runs out of charge, the BEV battery normally needs to be recharged at a stationary charging station. In an emergency situation, a portable charging system may be available for recharging. In either case, a BEV driver has to wait for several hours because the BEV must be kept stationary during the charging process. Therefore, as compared to a regular car which can get back on the road quickly, as soon as being refilled with fuel, recharging of a BEV is inconvenient. Such inconvenience is one of the factors that cause many BEV drivers to suffer from range anxiety, i.e., an anxiety over running out of electricity before the BEV reaches its destination. Therefore, an improved charging system is desired which allows a BEV to be charged faster and more efficiently.

BRIEF SUMMARY

[0003] According to an embodiment, an electrical storage system may comprise a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by an external high voltage power source; and an ultra-capacitor pack configured to store electric energy received from the external high voltage power source, wherein, the ultra-capacitor pack being configured to supply the electric energy stored in the ultra-capacitor pack to a vehicle battery of a battery electric vehicle when electrically connected to the vehicle battery; and the high voltage battery pack being configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

[0004] According to an embodiment, a vehicle may comprise a vehicle battery, an ultracapacitor pack configured to store electric energy received from an external high voltage power source, and a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by the external high voltage power source; wherein, the ultra-capacitor pack being configured to supply the electric energy stored in the ultra-capacitor pack to the vehicle battery when electrically connected to the vehicle battery; and the high voltage battery pack being configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

[0005] According to an embodiment, a method for charging a battery electric vehicle may comprise storing, with an ultra-capacitor pack, electric energy received from an external high voltage power source; supplying, with the ultra-capacitor pack, the electric energy stored in the ultra-capacitor pack to a vehicle battery of a battery electric vehicle in response to the ultracapacitor pack being electrically connected to the vehicle battery; and supplying, with a high voltage battery pack, electric energy stored in the high voltage battery pack to the ultra-capacitor pack in response to the high voltage battery pack being electrically connected to the ultracapacitor pack, wherein the high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by the external high voltage power source. ASPECTS OF THE INVENTION

[0006] According to an embodiment, an electrical storage system may comprise a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by an external high voltage power source; and an ultra-capacitor pack configured to store electric energy received from the external high voltage power source, wherein, the ultra-capacitor pack being configured to supply the electric energy stored in the ultra-capacitor pack to a vehicle battery of a battery electric vehicle when electrically connected to the vehicle battery; and the high voltage battery pack being configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

[0007] According to an embodiment, the high voltage battery pack is configured to store electric energy received from the external high voltage power source.

[0008] According to an embodiment, the high voltage battery pack is configured to: store the electric energy at an adjustable charging rate based on a state of battery cells in the high voltage battery pack, and/or the ultra-capacitor pack is configured to supply the electric energy stored in the ultra-capacitor pack to the vehicle battery at an adjustable charging rate based on a state of battery cells in the vehicle battery.

[0009] According to an embodiment, the electrical storage system may further comprise a controller configured to electrically connect the high voltage battery pack to the ultra-capacitor pack in response to at least one of the ultra-capacitor pack having stopped storing the electric energy received from the external high voltage power source for a predetermined time duration, or the electric energy stored in the ultra-capacitor pack being less than a predetermined energy threshold, or being instructed by a control system of the battery electric vehicle. [0010] According to an embodiment, the controller is further configured to monitor at least one of: a time duration for which the ultra-capacitor pack having stopped storing the electric energy received from the external high voltage power source; or an amount of electric energy stored in the ultra-capacitor pack.

[0011] According to an embodiment, the controller is further configured to electrically connect the ultra-capacitor pack to the vehicle battery in response to at least one of: an energy level in the vehicle battery being lower than a predetermined level threshold; or the vehicle battery beginning to discharge energy; or the vehicle battery having discharged energy for a predetermined duration.

[0012] According to an embodiment, the electrical storage system may further comprise a battery monitoring system configured to, monitor at least one of the energy level in the vehicle battery, or a time when the vehicle battery beginning to discharge energy, or a time duration for which the vehicle battery having discharged energy.

[0013] According to an embodiment, the electrical storage system may further comprise the vehicle battery of the battery electric vehicle; and a DC to DC power converter electrically connected between the ultra-capacitor pack and the vehicle battery, wherein the DC to DC power converter is configured to convert the electric energy supplied by the ultra-capacitor pack from a high voltage to a lower voltage.

[0014] According to an embodiment, the ultra-capacitor pack is further configured to store electric energy converted from heat energy emitted by at least one of the high voltage battery pack, or the ultra-capacitor pack, or the vehicle battery, or other components of the battery electric vehicle. [0015] According to an embodiment, the electrical storage system may further comprise an AC to DC converter configured to electrically connect the external high voltage power source to the high voltage battery pack and to the ultra-capacitor pack.

[0016] According to an embodiment, the electrical storage system may further comprise the external high voltage power source.

[0017] According to an embodiment, a vehicle may comprise a vehicle battery, an ultracapacitor pack configured to store electric energy received from an external high voltage power source, and a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by the external high voltage power source; wherein, the ultra-capacitor pack being configured to supply the electric energy stored in the ultra-capacitor pack to the vehicle battery when electrically connected to the vehicle battery; and the high voltage battery pack being configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

[0018] According to an embodiment, a method for charging a battery electric vehicle may comprise storing, with an ultra-capacitor pack, electric energy received from an external high voltage power source; supplying, with the ultra-capacitor pack, the electric energy stored in the ultra-capacitor pack to a vehicle battery of a battery electric vehicle in response to the ultracapacitor pack being electrically connected to the vehicle battery; and supplying, with a high voltage battery pack, electric energy stored in the high voltage battery pack to the ultra-capacitor pack in response to the high voltage battery pack being electrically connected to the ultracapacitor pack, wherein the high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by the external high voltage power source. [0019] According to an embodiment, the method may further comprise storing, with the high voltage battery pack, electric energy received from the external high voltage power source.

[0020] According to an embodiment, wherein, storing, with the high voltage battery pack, the electric energy at an adjustable charging rate based on a state of battery cells in the high voltage battery pack, and/or supplying, with the ultra-capacitor pack, the electric energy stored in the ultra-capacitor pack to the vehicle battery at an adjustable charging rate based on a state of battery cells in the vehicle battery.

[0021] According to an embodiment, the method may further comprise electrically connecting, with a controller, the high voltage battery pack to the ultra-capacitor pack in response to at least one of: the ultra-capacitor pack having stopped storing the electric energy received from the external high voltage power source for a predetermined time duration, or the electric energy stored in the ultra-capacitor pack being less than a predetermined energy threshold, or being instructed by a control system of the battery electric vehicle; and electrically connecting, with the controller, the ultra-capacitor pack to the vehicle battery in response to at least one of: an energy level in the vehicle battery being lower than a predetermined level threshold; or the vehicle battery beginning to discharge energy; or the vehicle battery having discharged energy for a predetermined duration.

[0022] According to an embodiment, the method may further comprise monitoring, with a battery monitoring system, at least one of the energy level in the vehicle battery, or a time when the vehicle battery beginning to discharge energy, or a time duration for which the vehicle battery having discharged energy.

[0023] According to an embodiment, the method may further comprise electrically connecting, via a DC to DC power converter, the ultra-capacitor pack to the vehicle battery, and converting, with the DC to DC power converter, the electric energy supplied by the ultracapacitor pack from a high voltage to a lower voltage.

[0024] According to an embodiment, the method may further comprise converting heat energy emitted by at least one of the high voltage battery pack, or the ultra-capacitor pack, or the vehicle battery, or other components of the battery electric vehicle into electric energy, and storing, with the ultra-capacitor pack, the electric energy converted from the heat energy.

[0025] According to an embodiment, the method may further comprise electrically connecting, with an AC to DC converter, the external high voltage power source to the high voltage battery pack and to the ultra-capacitor pack.

BRIEF DESCRIPTION OF DRAWINGS

[0026] The description below refers to the following drawings of which:

[0027] FIG. 1 shows a rapid charging system, according to an embodiment of the disclosure;

[0028] FIG. 2 shows a flow diagram, according to an embodiment of the disclosure; and

[0029] FIG. 3 shows another flow diagram, according to an embodiment of the disclosure.

DETAILED DESCRIPTION

[0030] The present disclosure relates to a Battery Electric Vehicle (BEV) that may include one or more vehicle batteries. The one or more vehicle batteries may be charged by an Electrical Storage System (ESS) onboard the BEV while the BEV is in motion. The ESS may include a high voltage battery pack and an ultra-capacitor pack. The high voltage battery pack may have a storage voltage which is substantially the same as an input voltage supplied by an external high voltage power source. The ultra-capacitor pack may store electric energy received from the external high voltage power source at the substantially same high voltage as well. The ultra-capacitor pack may supply its stored electric energy to the one or more vehicle batteries via an electrical connection. The high voltage battery pack may supply its stored electric energy to the ultra-capacitor pack via an electrical connection. Therefore, when a BEV is pulled up and connected to a charging station, a rapid charging solution may be provided by charging the onboarding ESS at a substantially same high voltage as the output of the charging station.

Additionally, the ESS may manage and optimize the charging process of the one or more vehicle batteries while the BEV is in motion, during which time the ultra-capacitor pack may be charged by the high voltage battery pack. A further advantage of longer driving range may be achieved.

[0031] Details of exemplary systems and methods to achieve the aforementioned advantages and benefits are described herein. However, alternatives to the structure, layout, size, arrangement, etc., are contemplated without departing from the goals and scopes of an improved charging system for the BEVs according to embodiments of the present disclosure.

[0032] Referring to FIG. 1, a rapid charging system 1 is shown. The rapid charging system 1 may include a charging station 10, an AC/DC converter 20, an Electrical Storage System (ESS) 30, a DC/DC converter 40, and a vehicle battery 50. In the rapid charging system 1, the charging station 10 may function as an external power source of a BEV. The charging station 10 may be a stationary charging station. The charging station 10 may be a high voltage charging station with a voltage higher than a suitable input charging voltage of the vehicle battery 50. The voltage of the charging station 10 supplied to the BEV may be very high, which could be several thousand volts. Thus, in this context, high voltage may mean the voltage at which the charging station is capable of transmitting power to the BEV, whose lowest value is higher than the input charging voltage of the vehicle battery 50. For example, high voltage may be the voltage being used in a transmission line from a substation to another substation, or from a substation to a residential community (e.g., about 3000 V).

[0033] The charging station 10 may be electrically connected to the AC/DC converter 20. When a BEV equipped with the ESS 30 is electrically connected to the AC/DC converter 20, the charging station 10 may transfer its high voltage AC power to the ESS 30 via the AC/DC converter 20. In response to such electrical connectivity, the AC/DC converter 20 may convert the high voltage AC power transferred from the charging station 10 to a substantially same high voltage DC power. Due to a reasonable loss that may occur during a conversion of the power from AC to DC, the output voltage of the AC/DC converter 20 may be substantially the same, but not exactly the same, as the input high voltage AC power. The ESS 30 onboard the BEV may in turn store the DC power. In an alternative embodiment, the AC/DC converter 20 may be equipped on the BEV, rather than being provided at a charging station (e.g., charging station 10).

[0034] By storing the converted DC power at a substantially same high voltage as the power provided by the charging station 10, the ESS 30 may store a large amount of power within minutes, rather than hours. In an example, the charging station 10 may have 3000V AC power , with 333 amps current. In this example the transferred charging power would be almost 1MWH (megawatt-hour) according to the equation of Power = Voltage x Amperage. The transmitted current may be handled by a reasonable sized charging cable (e.g., 70-90 mm²) without overheating the cable. Therefore, no incredibly large cables may be needed to implement the embodiments of the present disclosure.

[0035] With continued reference to FIG. 1, the ESS 30 may include a high voltage battery pack 31 and an ultra-capacitor pack 32. The high voltage battery pack 31 may have a storage voltage which is substantially the same as an input voltage supplied by the charging station 10 via the AC/DC converter 20. The high voltage battery pack 31 may include one or more batteries. Those one or more batteries may be connected with each other in an appropriate way to allow the high voltage battery pack 31 to store the converted DC power at the substantially same high voltage provided by the charging station 10. The appropriate connection may be a parallel connection, a serial connection or a mix thereof, which may depend on how high the input voltage is and the size of the batteries arranged in the high voltage battery pack 31. As an illustrated example, when the charging station 10 provides 3000V, the converted input DC power is substantially 3000V. The high voltage battery pack 31 is therefore a 3000V battery pack. In this instance, there may be three battery modules connected in series, with each battery module having roughly 1000 voltage capability. Battery modules having other voltage sizes may also be arranged in the high voltage battery pack 31, and the appropriate connections thereof may be changed accordingly.

[0036] The ultra-capacitor pack 32 may include one or more ultra-capacitors. In order for the ultra-capacitor pack 32 to store the converted DC power at the substantial same high voltage as the power provided from the charging station 10, the one or more ultra-capacitors may be connected with each other in an appropriate way. Similar to the high voltage battery pack 31, the appropriate connection may be a parallel connection, a serial connection or a mix thereof. Furthermore, additional factors may also be taken into account when considering how to connect the one or more ultra-capacitors. The additional factors may be a desired speed to store the converted DC power, a desired amount of power to be stored in the ultra-capacitor pack 32 within a certain period of time, or a combination thereof. [0037] With continued reference to FIG. 1, when the ESS 30 is electrically connected to the charging station 10, the ultra-capacitor pack 32 may store the converted DC power transferred from the charging station 10 at a substantially same high voltage. The ultra-capacitor pack 32 may supply its stored DC power to the vehicle battery 50 to charge the vehicle battery 50. The ultra-capacitor pack 32 may charge the vehicle battery 50 at a later time, after electrically disconnecting from the charging station 10. The ultra-capacitor pack 32 may charge the vehicle battery 50 with its stored DC power in response to an electrical connectivity therebetween. Once the battery cells of the vehicle battery 50 are fully charged, the electrical connection between the ultra-capacitor pack 32 and the vehicle battery 50 may be disconnected. Then the ultra-capacitor pack 32 may maintain any excess power and wait to recharge the vehicle battery 50 when an electrical connection is established again.

[0038] In an embodiment, whether to establish an electrical connection between the ultracapacitor pack 32 and the vehicle battery 50 may depend on the amount of electric energy in the vehicle battery 50. Various factors may be taken into account and used to indicate the amount of electric energy in the vehicle battery 50. For example, an electrical connection may be established when the amount of electric energy in the vehicle battery 50 is below a certain value (e.g., a predetermined level threshold), or the amount of electric energy decreases (e.g., vehicle battery 50 began to discharge its electric energy), or the vehicle battery 50 has discharged its electric energy for a predetermined period of time, etc., or any combination thereof.

[0039] In an embodiment, a controller 60 is deployed on the BEV to control the electric connectivity between the ultra-capacitor pack 32 and the vehicle battery 50. Then, when the amount of electric energy remaining in the vehicle battery 50 indicates charging is needed, the controller 60 may establish an electrical connection accordingly. In an embodiment, monitoring the change in the amount of electric energy in the vehicle battery 50 is performed by the controller 60 itself. In an alternative embodiment, the monitoring is performed by other system(s) on the BEV (e.g., a battery monitoring system 70). Then upon detecting a change in the amount of electric energy which indicates an electrical connection is needed to charge the vehicle battery 50, the battery monitoring system 70 may notify the controller 60. The controller 60 in turn performs functions to establish the electrical connection between the ultra-capacitor pack 32 and the vehicle battery 50.

[0040] In an embodiment, the battery monitoring system 70 may further monitor a state of health of battery cells in the vehicle battery 50. Then the ultra-capacitor pack 32 may charge the vehicle battery 50 at an adjustable charging rate based on the monitored state of health of the battery cells. By adjusting the charging rate to accommodate the health state of the battery cells, the battery cells may store electric energy supplied by the ultra-capacitor pack 32 without being overheated, which may degrade the performance of the battery cells. As an illustrated example, a C rate of the vehicle battery 50 may be monitored by the battery monitoring system 70. The C rate may indicate how much electric energy the vehicle battery 50 can accept during charging compared to its storage capacity. A C rate of 1C means the vehicle battery 50 can accept the total capacity of its battery cells within 1 hour. The ultra-capacitor pack 32 may charge the vehicle battery 50 at a rate which is adjusted to not exceed the monitored rated C value, thereby not overburdening the battery cells of the vehicle battery 50.

[0041] With continued reference to FIG. 1, in an embodiment, for safety purposes, the

DC/DC converter 40 may be deployed between the ultra-capacitor pack 32 and the vehicle battery 50. In this case, the DC/DC converter 40 may perform a conversion on the voltage of the DC power supplied from the ultra-capacitor pack 32. As discussed above, the DC power supplied by the ultra-capacitor pack 32 has a high voltage which is substantially the same as the voltage provided from the charging station 10. The DC/DC converter 40 may convert the DC power from a high input voltage to a lower output voltage (e.g., from a 3000V to a voltage under 1000V). The lower output voltage may be an appropriate voltage which is suitable to be an input charging voltage for the vehicle battery 50 (e.g., 400-800V for a heavy-duty vehicle). The lower output voltage may also be a safe operation voltage for auto maintenance engineers.

[0042] With continued reference to FIG.l, as the DC power is transferred from the ultracapacitor pack 32 to the vehicle battery 50, the power stored in the ultra-capacitor pack 32 decreases. In such case, the high voltage battery pack 31 may supply power to the ultra-capacitor pack 32 when being electrically connected to the ultra-capacitor pack 32. In other words, the electrical connection between the high voltage battery pack 31 and the ultra-capacitor pack 32 may be established in response to a change of the amount of power stored in the ultra-capacitor pack 32 (e.g., the stored power is less than a predetermined threshold). Alternatively or additionally, such electrical connection may be established in response to the ultra-capacitor pack 32 being disconnected from the charging station 10, thus no longer storing power from the charging station 10 for a predetermined time duration, or when instructed to do so by a control system of the BEV, or a combination thereof. In an embodiment, the electrical connectivity between the high voltage battery pack 31 and the ultra-capacitor pack 32 may be controlled by the controller 60. The controller 60 may establish an electrical connection in response to any of the parameters monitored by itself or by the battery monitoring system 70.

[0043] After supplying stored power to the ultra-capacitor pack 32, the high voltage battery pack 31 may have less power stored therein. In an embodiment, when the ESS 30 is electrically connected for charging to the charging station 10 via the AC/DC converter 20, the high voltage battery pack 31 also may be electrically connected to the charging station 10 via the AC/DC converter 20. Then the high voltage battery pack 31 may store the converted DC power supplied from the charging station 10 during the charging process of the ultra-capacitor pack 32.

[0044] A plurality of factors may be considered to determine whether to establish an electrical connection between the high voltage battery pack 31 and the charging station 10. One of such factors may be when power stored in the high voltage battery pack 31 is below a predetermined threshold. Another factor may be when the power stored in the ultra-capacitor pack 32 is below a predetermined threshold. Thus, when the amount of power stored in the ultra-capacitor pack 32 is too low, the high voltage battery pack 31 may be configured to store power transferred from the charging station 10. Then after the ESS 30 is disconnected from the charging station 10, the high voltage battery pack 31 may supply its stored power to the ultracapacitor pack 32. In an embodiment, the high voltage battery pack 31 may supply its stored power later, at an appropriate time. The appropriate time may be, such as in response to the stored power in the ultra-capacitor pack 32 is less than a predetermined threshold, a disconnection of the ultra-capacitor pack 32 from the charging station 10 for a certain period of time, or as instructed by a control system as discussed above.

[0045] In an embodiment, the high voltage battery pack 31 may simply always be connected to the charging station 10 and store power during the period of time that the ultracapacitor pack 32 is charging. In another embodiment, any of the above and also other additional factors may be considered in a flexible way, depending on how much power the BEV needs to store, the desired charging time of the BEV and the high voltage level provided by the charging station 10. [0046] In an embodiment, the battery monitoring system 70 may monitor the state of health of the battery cells in the high voltage battery pack 31. Then the charging rate of the high voltage battery pack 31 may be adjusted by the ultra-capacitor pack 32 to accommodate to the monitored state of health of the battery cells. In an embodiment, the ultra-capacitor pack 32 may change the current that it splits with the high voltage battery pack 31 during charging by the charging station 10, to adjust the charging rate of the high voltage battery pack 31. This may be implemented in a variety of ways, such as by changing its internal connection relationship between or among the two or more ultra-capacitors within the ultra-capacitor pack 32.

[0047] In an embodiment, the ultra-capacitor pack 32 may store electric energy converted from heat energy emitted by the high voltage battery pack 31, the ultra-capacitor pack 32 itself, the AC/DC converter 20 if equipped on the BEV, the DC/DC converter 40, the vehicle battery 50, or any other components of the BEV. If the converted energy exceeds the storage limit of the ultra-capacitor pack 32, the excess energy may be stored further in the high voltage battery pack 31. As an example, the techniques used by a hybrid vehicle may be used to collect and convert the emitted heat energy into electric energy. If the DC/DC converter 40 is a bi-directional converter, it may be used for converting the converted energy from a lower voltage to a higher voltage. Otherwise, an additional DC/DC converter may be arranged to perform such conversion. Also, the DC/DC converter may be used to provide charge from the vehicle battery 50 to the high voltage battery pack 31.

[0048] When there is still excessive heat and the ambient temperature is high, a chiller may be used to remove the extra heat to cool the charging system. In another embodiment, the excessive heat may be used to keep the battery cells at their respective optimal operating temperature when the ambient temperature is low. [0049] In the various embodiments descried above with reference to FIG. 1, an exemplary rapid charging system 1 is illustrated. However, it’s noted that the ESS may include one or more high voltage battery packs and one or more ultra-capacitor packs as needed. Also, a separate controller 60 is not required. For example, the corresponding functions of the controller 60 could be implemented by an existing onboarding control system of the BEV or be incorporated into other appropriate systems of the BEV. In some cases, the BEV may include a tractor and a trailer. In some cases, each of the tractor and the trailer may include one or more vehicle batteries that may be charged by the ESS of the present disclosure. The various other components may be arranged on the tractor or trailer as appropriate. The functions of the other components may also be combined as appropriate.

[0050] Furthermore, in the embodiments descried above, the charging station 10 may function as an external power source of a BEV and supply its high voltage AC power to the onboard ESS 30. However, it may be understood that the connection is bi-directional. The ESS 30 may become an external power source to the charging station 10 as well. For example, when the power from an electric grid goes down and the charging station 10 is required to charge a battery of other electrical equipment. Then the ESS 30 may supply its stored DC power via the AC/DC converter 20 in cases where the AC/DC converter 20 may convert DC and AC bidirectionally. Otherwise, a DC/ AC converter may be used to substitute for the AC/DC converter 20 to establish an electrical connection in this scenario. Also, the ESS 30 may supply its stored DC power via an output port.

[0051] It may also be understood that the ESS 30 is not limited to merely supply its stored power to the vehicle battery 50. The ESS 30 may act as a power source for a plurality of other electrical devices instead (e.g., when power is not easy to find, like during camping or when there is an emergency such as a power outage caused by an extreme weather), whether portable or non-portable, whether onboard the BEV or not. For example, the ESS 30 may supply its power to another ESS onboard another BEV when needed. The ESS 30 may also charge another battery of any other electrical devices directly, or via the DC/DC converter 40.

[0052] In another example, the ESS 30 may supply power via the charging station. For example, in an industrial park, one or several ESSs may be used to provide power. In this scenario, a number of refrigerated trucks may be parked at a trucking facility. The ESS(s) may provide power to the facility’s power infrastructure via the charging stations to power the refrigeration units, or other components connected to the infrastructure. The ESS may be bidirectional to provide high voltage AC power back to the charging station, which is connected to the power infrastructure. The charging stations may include a control unit that can switch from the mode of charging the ESS to providing power from the ESS. In the above scenarios, necessary converters or devices may be used in addition to the DC/DC converter, DC/ AC converter, or as a substitute of the DC/DC converter 40, to establish a bi-directional electrical connection. That are bi-directional converters, or two one-way converters.

[0053] Referring to FIG. 2, a flow diagram illustrating a rapid charging method according to an embodiment of the present disclosure is shown. With continued reference to FIG. 1, relevant devices appropriate to perform steps of this method are illustrated therein. At step S 201, the converted DC power may be stored in the ultra-capacitor pack 32. At step S 202, in response to the ultra-capacitor pack 32 being electrically connected to the vehicle battery 50, the power stored in the ultra-capacitor pack 32 may be supplied to the vehicle battery 50. At step S 203, in response to the high voltage battery pack 31 being electrically connected to the ultra- capacitor pack 32, the power stored in the high voltage battery pack 31 may be supplied to the ultra-capacitor pack 32.

[0054] Referring to FIG. 3, another flow diagram of a rapid charging method according to another embodiment of the present disclosure is shown. Similarly, continued reference is made to FIG. 1 as an illustrating example of appropriate devices to perform steps of this method. At step S 301, via the AC/DC converter 20, an electrical connection between the charging station 10 and the high voltage battery pack 31, and between the charging station 10 and the ultracapacitor pack 32 is established. At step S 302, the converted DC power may be stored into the ultra-capacitor pack 32. At step S 303, the converted DC power may be stored into the high voltage battery pack 31. At step S 304, in response to the ultra-capacitor pack 32 being electrically connected to the vehicle battery 50, the power stored in the ultra-capacitor pack 32 may be supplied to the vehicle battery 50. At step S 305, in response to the high voltage battery pack 31 being electrically connected to the ultra-capacitor pack 32, the power stored in the high voltage battery pack 31 may be supplied to the ultra-capacitor pack 32.

[0055] Although FIGs 2 and 3 illustrate steps of a method sequentially, the steps may be further combined and/or separated, or the sequence may be further adjusted based on appropriate needs without departing from the goals and scopes of the present disclosure.

[0056] To be concise, the descriptions made with reference to FIG. 1 in conjunction with components illustrated therein will not be repeated in describing FIGS 2 and 3. Functions or operations descried above also may be performed as a step of a method according to an embodiment of the disclosure. In other words, any features or characteristics thereof could also be incorporated into a method according to an embodiment of the disclosure. [0057] In the above embodiments, the electrical connection and electrical connectivity refer to any form connection that is appropriate for transferring electric power or energy, such as wired or wireless electrical connection, magnetic connection, induction or any combination thereof. In the above embodiments, a substantially same voltage means the values of two voltages are close to each other, but not necessarily exactly the same. A reasonable difference therebetween may be understood and acceptable due to a plurality of factors, such as a loss caused by an AC/DC conversion, heat emitted during a power transmission via an electrical connection, etc.

[0058] Use of language such as “at least one of X, Y, and Z,” “at least one of X, Y, or Z,” “at least one or more of X, Y, and Z,” “at least one or more of X, Y, or Z,” “at least one or more of X, Y, and/or Z,” or “at least one of X, Y, and/or Z,” are intended to be inclusive of both a single item (just X, or just Y, or just Z) and multiple items (i.e., {X and Y}, {X and Z}, {Y and Z}, or {X, Y, and Z }). “At least one of’ is not intended to convey a requirement that each possible item must be present.

[0059] Although the foregoing description is directed to the preferred embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the invention.

Moreover, features described in connection with one embodiment of the invention may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. An electrical storage system, the system comprising: a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by an external high voltage power source; and an ultra-capacitor pack configured to store electric energy received from the external high voltage power source, wherein, the ultra-capacitor pack being configured to supply the electric energy stored in the ultracapacitor pack to a vehicle battery of a battery electric vehicle when electrically connected to the vehicle battery; and the high voltage battery pack being configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

2. The electrical storage system of claim 1, wherein the high voltage battery pack is configured to store electric energy received from the external high voltage power source.

3. The electrical storage system of claim 2, wherein the high voltage battery pack is configured to store the electric energy at an adjustable charging rate based on a state of battery cells in the high voltage battery pack, and/or the ultra-capacitor pack is configured to supply the electric energy stored in the ultracapacitor pack to the vehicle battery at an adjustable charging rate based on a state of battery cells in the vehicle battery.

4. The electrical storage system of claim 1, further comprising: a controller configured to electrically connect the high voltage battery pack to the ultracapacitor pack in response to at least one of: the ultra-capacitor pack having stopped storing the electric energy received from the external high voltage power source for a predetermined time duration, or the electric energy stored in the ultra-capacitor pack being less than a predetermined energy threshold, or being instructed by a control system of the battery electric vehicle.

5. The electrical storage system of claim 4, wherein the controller is further configured to monitor at least one of: a time duration for which the ultra-capacitor pack having stopped storing the electric energy received from the external high voltage power source; or an amount of electric energy stored in the ultra-capacitor pack.

6. The electrical storage system of claim 4, wherein the controller is further configured to electrically connect the ultra-capacitor pack to the vehicle battery in response to at least one of: an energy level in the vehicle battery being lower than a predetermined level threshold; or the vehicle battery beginning to discharge energy; or the vehicle battery having discharged energy for a predetermined duration.

7. The electrical storage system of claim 6, further comprising a battery monitoring system configured to, monitor at least one of the energy level in the vehicle battery, or a time when the vehicle battery beginning to discharge energy, or a time duration for which the vehicle battery having discharged energy.

8. The electrical storage system of claim 1, further comprising: the vehicle battery of the battery electric vehicle; and a DC to DC power converter electrically connected between the ultra-capacitor pack and the vehicle battery, wherein the DC to DC power converter is configured to convert the electric energy supplied by the ultra-capacitor pack from a high voltage to a lower voltage.

9. The electrical storage system of claim 1, wherein the ultra-capacitor pack is further configured to store electric energy converted from heat energy emitted by at least one of the high voltage battery pack, or the ultra-capacitor pack, or the vehicle battery, or other components of the battery electric vehicle.

10. The electrical storage system of claim 1, further comprising: an AC to DC converter configured to electrically connect the external high voltage power source to the high voltage battery pack and to the ultra-capacitor pack.

11. The electrical storage system of claim 1, further comprising the external high voltage power source.

12. A vehicle comprising: a vehicle battery, an ultra-capacitor pack configured to store electric energy received from an external high voltage power source, and a high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by the external high voltage power source; wherein, the ultra-capacitor pack being configured to supply the electric energy stored in the ultracapacitor pack to the vehicle battery when electrically connected to the vehicle battery; and the high voltage battery pack being configured to supply electric energy stored in the high voltage battery pack to the ultra-capacitor pack when electrically connected to the ultra-capacitor pack.

13. A method for charging a battery electric vehicle, the method comprising: storing, with an ultra-capacitor pack, electric energy received from an external high voltage power source; supplying, with the ultra-capacitor pack, the electric energy stored in the ultra-capacitor pack to a vehicle battery of a battery electric vehicle in response to the ultra-capacitor pack being electrically connected to the vehicle battery; and supplying, with a high voltage battery pack, electric energy stored in the high voltage battery pack to the ultra-capacitor pack in response to the high voltage battery pack being electrically connected to the ultra-capacitor pack, wherein the high voltage battery pack having a storage voltage substantially the same as an input voltage supplied by the external high voltage power source.

14. The method of claim 13, further comprising: storing, with the high voltage battery pack, electric energy received from the external high voltage power source.

15. The method of claim 14, wherein: storing, with the high voltage battery pack, the electric energy at an adjustable charging rate based on a state of battery cells in the high voltage battery pack, and/or supplying, with the ultra-capacitor pack, the electric energy stored in the ultra-capacitor pack to the vehicle battery at an adjustable charging rate based on a state of battery cells in the vehicle battery.

16. The method of claim 13, further comprising: electrically connecting, with a controller, the high voltage battery pack to the ultracapacitor pack in response to at least one of: the ultra-capacitor pack having stopped storing the electric energy received from the external high voltage power source for a predetermined time duration, or the electric energy stored in the ultra-capacitor pack being less than a predetermined energy threshold, or being instructed by a control system of the battery electric vehicle; and electrically connecting, with the controller, the ultra-capacitor pack to the vehicle battery in response to at least one of: an energy level in the vehicle battery being lower than a predetermined level threshold; or the vehicle battery beginning to discharge energy; or the vehicle battery having discharged energy for a predetermined duration.

17. The method of claim 16, further comprising: monitoring, with a battery monitoring system, at least one of the energy level in the vehicle battery, or a time when the vehicle battery beginning to discharge energy, or a time duration for which the vehicle battery having discharged energy.

18. The method of claim 13, further comprising: electrically connecting, via a DC to DC power converter, the ultra-capacitor pack to the vehicle battery, and converting, with the DC to DC power converter, the electric energy supplied by the ultracapacitor pack from a high voltage to a lower voltage.

19. The method of claim 13, further comprising: converting heat energy emitted by at least one of the high voltage battery pack, or the ultra-capacitor pack, or the vehicle battery, or other components of the battery electric vehicle into electric energy, and storing, with the ultra-capacitor pack, the electric energy converted from the heat energy.

20. The method of claim 13, further comprising: electrically connecting, with an AC to DC converter, the external high voltage power source to the high voltage battery pack and to the ultra-capacitor pack.