CHARGER SELECTION SYSTEM, CHARGER SELECTION METHOD, AND CHARGER SELECTION PROGRAM

A charge control map for chargers specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the chargers, the state of charge (SOC) of a secondary battery mounted in an electrically driven vehicle to be charged, the voltage of the secondary battery, and time. A charge control map for an electrically driven vehicle specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the secondary battery, the SOC of the secondary battery, the voltage of the secondary battery, and time. A charger selection unit (118) selects a charger used for charging any electrically driven vehicle of a plurality of electrically driven vehicles from among the plurality of chargers. The charger selection unit (118) selects at least one charger that least limits the charging performance of the electrically driven vehicle to be charged.

TECHNICAL FIELD

The present disclosure relates to a charger selection system, a charger selection method, and a charger selection program that select a charger used for charging an electrically driven vehicle from among a plurality of chargers.

BACKGROUND ART

In recent years, the use of electrically driven vehicles such as electric vehicles (EV) and plug-in hybrid vehicles (PHV) has been growing. As the infrastructure development associated with this, the use of recharging facilities is also growing. With the evolution of compact mobility and the spread of car sharing, charging facilities are being used for a wide variety of electrically driven vehicles. The charging facilities are required to have high durability and complex control.

In order to charge a secondary battery mounted in an electrically driven vehicle as planned, it is necessary to charge the battery in a charging facility that meets the requirements of the vehicle. In this regard, a system has been suggested for matching an electric vehicle and a charging facility based on information on the electric vehicle and the power supply information on the charging facility (see, for example, Patent Literature 1).[Patent Literature 1] JP 2014-532350 (published Japanese translation of PCT international publication for patent application)

SUMMARY OF INVENTION

Technical Problem

The charging performance including the upper limit charging current of a charging facility varies depending on the model and the time of introduction. The charging performance of an electrically driven vehicle also varies depending on the model and grade. In the case of charging at a charging facility with charging performance lower than that of an electrically driven vehicle, the charging performance of the electrically driven vehicle cannot be fully utilized.

In this background, a general purpose of the present disclosure is to provide a technology for appropriately selecting a charging facility to be used to charge a specific electrically driven vehicle from among a plurality of charging facilities.

Solution to Problem

A charger selection system according to one embodiment of the present disclosure includes: a first charge control map holding unit that holds a charge control map for a plurality of chargers; a second charge control map holding unit that holds a charge control map for a plurality of electrically driven vehicles; and a charger selection unit that selects a charger used for charging any one electrically driven vehicle of the plurality of electrically driven vehicles from among the plurality of chargers. A charge control map for a plurality of chargers specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the chargers, the SOC of a secondary battery mounted in an electrically driven vehicle to be charged, the voltage of the secondary battery, and time, a charge control map for the electrically driven vehicle specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the secondary battery, the SOC of the secondary battery, the voltage of the secondary battery, and time, and the charger selection unit selects at least one charger that least limits the charging performance of the electrically driven vehicle to be charged.

Optional combinations of the aforementioned constituting elements and implementations of the present disclosure in the form of apparatuses, methods, systems, computer programs, etc., may also be practiced as additional modes of the present disclosure.

Advantageous Effects of Invention

According to the present disclosure, a charging facility to be used to charge a specific electrically driven vehicle can be appropriately selected from among a plurality of charging facilities.

DESCRIPTION OF EMBODIMENTS

FIG.1is a diagram for explaining the outline of a charger selection system1according to an embodiment. The charger selection system1according to the embodiment is a system suitable for use by a delivery operator. The charger selection system1may be constructed on an in-house server installed at a service provider's own facility or data center that provides operation management support services for an electrically driven vehicle3, for example. Further, the charger selection system1may be constructed on a cloud server used based on a cloud service contract. Also, the charger selection system1may be constructed on a plurality of servers distributed and installed at a plurality of bases, which are data centers and own facilities. The plurality of servers may be any of a combination of a plurality of in-house servers, a combination of a plurality of cloud servers, or a combination of an in-house server and a cloud server.

Each delivery operator has a plurality of electrically driven vehicles3, at least one charger4, and a delivery base for parking the electrically driven vehicles3. The electrically driven vehicles3are connected to the charger4through a charging cable5, and secondary batteries mounted in the electrically driven vehicles3are charged from the charger4via the charging cable5.

An operation management terminal device7is installed at the delivery base of the delivery operator. The operation management terminal device7consists of a PC, for example. The operation management terminal device7is used to manage the plurality of electrically driven vehicles3belonging to the delivery base. The operation manager of the delivery operator can use the operation management terminal device7so as to create delivery and charging plans for the electrically driven vehicles3. The operation management terminal device7can access the charger selection system1via a network2.

The network2is a general term for communication channels such as the Internet, a leased line, a virtual private network (VPN), etc., regardless of their communication media or protocols. As the communication media, for example, cellular phone networks (cellular networks), wireless LANs, wired LANs, optical fiber networks, ADSL networks, CATV networks, etc., can be used. For example, transmission control protocol (TCP)/internet protocol (IP), user datagram protocol (UDP)/IP, Ethernet (registered trademark), etc., can be used as the communication protocols.

The plurality of electrically driven vehicles3have a wireless communication function and can be connected to the network2. The electrically driven vehicles3can transmit vehicle information to the charger selection system1via the network2. A plurality of chargers4are connected to the network2, and the chargers4can transmit charger information and charging logs to the charger selection system1via the network2.

FIG.2is a diagram showing a configuration example of a charger4and an electrically driven vehicle3. The charger4includes a rectifier circuit41, a power factor correction (PFC) circuit42, a DC/DC converter43, a control unit44, a current sensor45, a voltage sensor46, and a temperature sensor47. In the embodiment, a quick charger compliant with CHAdeMO (registered trademark) is assumed.

The rectifier circuit41performs full-wave rectification of an AC voltage, for example, three-phase AC 200V, supplied from a commercial power system6. The PFC circuit42improves the power factor of the full-wave rectified power. The DC/DC converter43is an isolated DC/DC converter and controls the current or voltage of DC power supplied from PFC circuit42. The current sensor45detects the output current of the DC/DC converter43and outputs the output current to the control unit44. The voltage sensor46detects the output voltage of the DC/DC converter43and outputs the output voltage to the control unit44. The temperature sensor47detects the temperature inside the charger4and outputs the temperature to the control unit44. The temperature sensor47may be installed outside the charger4so as to detect the outside temperature of the location where the charger4is installed and output the outside temperature to the control unit44.

The control unit44controls the output current or output voltage of the DC/DC converter43based on the output current, the output voltage, or the temperature that is input. The control unit44includes a microcontroller, a communication controller, and a nonvolatile memory, e.g., an electrically erasable programmable read-only memory (EEPROM) and a flash memory.

A controller area network (CAN) is employed as the communication method between the charger4and the electrically driven vehicle3via the charging cable5in CHAdeMO and ChaoJi. Power line telecommunication (PLC) is employed in Combo. The charging cable5compliant with CHAdeMO includes a CAN communication line. The control unit44includes a CAN controller as a communication controller for controlling communication with the vehicle control unit36in the electrically driven vehicle3.

The control unit44also includes a LAN controller as a communication controller for connecting to the network2. The control unit44can transmit charger information to the charger selection system1via the network2. The charger information can include a charger ID, a model, a network address, e.g., IP address, MAC address, installation location information, administrator information, etc.

The electrically driven vehicle3includes a battery pack31, a battery control unit32, a current sensor33, a voltage sensor34, a temperature sensor35, a vehicle control unit36, a motor37, an inverter38, a first relay39, a second relay310, an on-board charger311, a GPS sensor312, a vehicle speed sensor313, a wireless communication unit314, and an antenna315.

The battery pack31includes a plurality of cells connected in series or in series-parallel. For the cells, lithium-ion battery cells, nickel hydrogen battery cells, lead battery cells, etc., can be used. Hereinafter, an example is assumed in the present specification where lithium-ion battery cells, with nominal voltage of 3.6-3.7 V, are used.

The current sensor33detects the current flowing in the battery pack31and outputs the current to the battery control unit32. The voltage sensor34detects the voltage of battery pack31and outputs the voltage to battery control unit32. Although not shown in the figure, the voltage sensor34can also detect the voltage of each of the plurality of cells connected in series that are included in the battery pack31. The temperature sensor35detects the temperature of the battery pack31and outputs the temperature to the battery control unit32. The temperature sensor35may be installed at multiple locations on the battery pack31.

The battery control unit32, also referred to as BMU or BMS, includes a microcontroller, a communication controller, and a nonvolatile memory. The battery control unit32and the vehicle control unit36are connected via an in-vehicle network, e.g., CAN or local interconnect network (LIN). The communication controller controls communication with the vehicle control unit36.

The battery control unit32estimates the state of charge (SOC), the full charge capacity (FCC), and the state of health (SOH) of each of the plurality of cells included in the battery pack31.

The battery control unit32combines the open circuit voltage (OCV) method and the current integration method so as to estimate the SOC. The OCV method is a method for estimating the SOC based on the OCV of the cell and the SOC-OCV curve of the cell. The SOC-OCV curve of a cell is created in advance based on a characteristic test performed by the battery manufacturer and is registered in the internal memory of the microcontroller at the time of shipment.

The current integration method is a method for estimating the SOC based on the OCV at the start of charging/discharging of a cell and the integrated value of the current flowing in the cell. In the current integration method, current measurement errors accumulate as the charging/discharging time becomes longer. Therefore, the SOC estimated according to the current integration method is preferably corrected using the SOC estimated according to the OCV method.

The battery control unit32can estimate the FCC by dividing the current integrated value from the start to the end of charging/discharging by the SOC change during that period. The SOC at the start and the SOC at the end of charging/discharging can be obtained from the measured OCV and SOC-OCV curve, respectively. SOH is defined by the ratio of the current FCC to the initial FCC, and the lower the value thereof (the closer to 0%), the more the deterioration is progressing.

The battery control unit32transmits the voltage, current, temperature, SOC, FCC, and SOH of the battery pack31and each cell to the vehicle control unit36via the in-vehicle network.

The vehicle control unit36is a vehicle electronic control unit (ECU) that controls the entire electrically driven vehicle3and may consist of, for example, an integrated vehicle control module (VCM). The vehicle control unit36includes a communication controller for connecting to the in-vehicle network and for communicating with the control unit44of the charger4via the charging cable5, e.g., a CAN controller.

The electrically driven vehicle3includes a three-phase AC motor as a drive motor37. The inverter38converts DC power supplied from the battery pack31into AC power and supplies the AC power to the motor37during power running. During regeneration, the inverter converts the AC power supplied from the motor37to DC power and supplies the DC power to the battery pack31. The motor37rotates according to the AC power supplied from the inverter38during power running. During regeneration, the motor converts rotational energy caused due to deceleration to AC power and supplies the Ac power to the inverter38.

The first relay39is a contactor that is inserted into wiring that connects the battery pack31and the inverter38. The vehicle control unit36controls the first relay39to be in an ON state, a closed state, when the vehicle is running so as to electrically connect the battery pack31and the inverter38. In principle, the vehicle control unit36controls the first relay39to be in an OFF state, an open state, when the vehicle is not running so as to electrically disconnect the battery pack31from the inverter38.

The second relay310is a relay that is inserted into the DC wiring that connects the battery pack31and an inlet into which the charging cable5is inserted. The battery control unit32controls the second relay310to be in the ON state when charging from the charger4is being performed and controls the second relay310to be in the OFF state after the charging is completed.

The on-board charger311is used for charging with AC power by inserting a cable with an AC plug into a regular charger or a general-purpose AC outlet. The on-board charger311rectifies the AC voltage supplied via the cable with an AC plug in full wave, improves the power factor of the full-wave rectified power, and controls the current or voltage of the DC power with an improved power factor so as to supply to the battery pack31.

The GPS sensor312detects the position information of the electrically driven vehicle3and transmits the detected position information to the vehicle control unit36. The GPS sensor312specifically receives radio waves each including its transmission time from a plurality of GPS satellites and calculates the latitude and longitude of a reception point based on the plurality of transmission times respectively included in the received radio waves.

The vehicle speed sensor313generates a pulse signal proportional to the rotation speed of the axle and transmits the generated pulse signal to the vehicle control unit36. The vehicle control unit36detects the speed of the electrically driven vehicle3based on the pulse signal received from the vehicle speed sensor313.

The wireless communication unit314performs a signal process for wireless connection to the network2via the antenna315. As wireless communication networks to which the electrically driven vehicle3can wirelessly connect, for example, cellular phone networks (cellular networks), wireless LAN, vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), electronic toll collection systems (ETC systems), and distance scanning resistance control (DSRC), etc., can be used.

The vehicle control unit36can transmit vehicle information from the wireless communication unit314to the charger selection system1via the network2. The vehicle information can include vehicle ID, vehicle model, network address, e.g., IP address, MAC address, type and model number of the battery pack31mounted in the electrically driven vehicle3, and the like.

In a state where the electrically driven vehicle3and the charger4are being connected by the charging cable5, the vehicle control unit36can transmit the vehicle ID, the FCC and SOC of the battery pack31, a charging current command value, and the like to the control unit44of the charger4via the CAN communication line in the charging cable5.

The battery control unit32in the electrically driven vehicle3generates a charging current command value as control during charging. In the case of quick charging, the battery control unit32basically sets the upper limit current of the battery pack31as the charging current command value. The battery control unit32changes the upper limit current according to the conditions during charging from the viewpoint of ensuring safety during the charging and preventing deterioration of the battery pack31. For example, the battery control unit32lowers the upper limit current as the SOC of the battery pack31increases. The battery control unit32also lowers the upper limit current as the temperature of the battery pack31becomes lower than or higher than the normal temperature. Hereafter, the relationship between the charging conditions during charging and the upper limit current value in the electrically driven vehicle3is referred to as a vehicle charge control map.

The battery control unit32transmits the generated charging current command value to the control unit44of the charger4via the vehicle control unit36and the charging cable5. As basic control, the control unit44of the charger4controls the DC/DC converter43such that the output current of the DC/DC converter43becomes the charging current command value received from the battery control unit32.

As control during the charging, the control unit44of the charger4limits the output current of the DC/DC converter43to be the upper limit current or less. The control unit44of the charger4changes the upper limit current according to the conditions during the charging from the viewpoint of ensuring safety during the charging. For example, the control unit44may lower the upper limit current as the temperature of the charger4increases. Further, the control unit44may lower the upper limit current as the SOC of the battery pack31being charged increases. Hereafter, the relationship between the charging conditions during the charging and the upper limit current value in the charger4is referred to as a charger charge control map.

The control unit44of the charger4limits the output current of the DC/DC converter43to the upper limit current set by the control unit44when the charging current command value received from the battery control unit32is higher than the upper limit current according to the conditions during charging.

The control unit44of the charger4transmits a charging log to the charger selection system1via the network2after the charging for the electrically driven vehicle3is completed. Prior to transmitting the charging log, the control unit44of the charger4receives from the vehicle control unit36the battery pack ID and transition data of the SOC, voltage, current, and temperature of the battery pack31being charged.

The charging log transmitted from the charger4to the charger selection system1can include the charger ID, the vehicle ID, the charging start time, the charging end time, the output current, output voltage, and temperature of the charger4, the battery pack ID of the battery pack31, transition data of the SOC, voltage, current, temperature, and charging current command value transmitted from the electrically driven vehicle3to the charger4of the battery pack31, etc.

FIG.3is a diagram showing a configuration example of the charger selection system1according to the embodiment. The charger selection system1includes a processing unit11, a memory unit12, and a communication unit13. The communication unit13is a communication interface for connecting to the network2by wire or wirelessly.

The processing unit11includes a vehicle information acquisition unit111, a charger information acquisition unit112, a charging log acquisition unit113, a charge control map update unit114, a charger search receiving unit115, a charging time determination unit116, a charging profile generation unit117, a charger selection unit118, and a charger guidance notification unit119.

The function of the processing unit11can be realized by cooperation of hardware resources and software resources, or only by hardware resources. As the hardware resources, CPU, ROM, RAM, graphics processing unit (GPU), application specific integrated circuit (ASIC), field programmable gate array (FPGA), and other LSIs can be used. Programs such as operating systems and applications can be used as the software resources.

The memory unit12includes a charger master holding unit121, a vehicle master holding unit122, a charger charge control map holding unit123, and a vehicle charge control map holding unit124. The memory unit12includes a non-volatile recording medium such as HDD, SSD, etc., and stores various types of data.

The charger master holding unit121holds master information of chargers4registered with a charger selection service. The chargers4registered with the charger selection service include chargers4installed at public charging stations. The master information of a charger4includes a charger ID, a model, a network address, an installation location, an administrator, a catalog specification, etc.

The vehicle master holding unit122holds master information of electrically driven vehicles3registered with the charger selection service. The master information of an electrically driven vehicle3includes a vehicle ID, a model, a network address, an administrator, the type of a battery pack31that is mounted, a model number, a catalog specification, etc.

The charger charge control map holding unit123holds charge control maps for a plurality of chargers4registered in the charger master holding unit121. The charge control map of a charger4specifies an upper limit current according to the temperature of the charger4, an upper limit current according to the SOC (or voltage) of the battery pack31to be charged, or an upper limit current according to a combination of the temperature of the charger4and the SOC (or voltage) of the battery pack31to be charged. Time can also be used as a charging condition during charge control. For example, as a countermeasure against rush current at the start of charging, a charger4may perform slow-start control such as performing charging at10A or less for five minutes after the start of the charging. In this case, the upper limit current at the start of the charging is specified by time only or a combination of the time and the temperature.

The vehicle charge control map holding unit124holds charge control maps for a plurality of electrically driven vehicles3registered in the vehicle master holding unit122. The charge control map of an electrically driven vehicle3specifies an upper limit current according to the temperature of the battery pack31, an upper limit current according to the SOC (or voltage) of the battery pack31to be charged, or an upper limit current according to a combination of the temperature of the battery pack31and the SOC (or voltage) of the battery pack31. Time can also be used as a charging condition during charge control.

FIGS.4A-4Bare diagrams showing examples of a charge control map for a charger4and a charge control map for an electrically driven vehicle3.FIG.4Ashows an example of a map that specifies the upper current limit in a charger A according to the combination of the temperature of the charger4and the SOC of the battery pack31to be charged.FIG.4Bshows an example of a map that specifies the upper current limit in an electrically driven vehicle A according to the combination of the temperature of the battery pack31and the SOC of the battery pack31.

The charge control map for the charger4shown inFIG.4Ashows an example in which the upper limit current is changed according to the SOC of the battery pack31to be charged, without considering the temperature of the charger4. The upper current limit may be changed according to the combination of the SOC of the battery pack31to be charged and the temperature of the charger4. Alternatively, the upper limit current may be changed according to the temperature of the charger4without considering the SOC of the battery pack31to be charged.

In the case of a typical lithium-ion battery, the OCV is 2.9V at 0% SOC, 3.3V at 10% SOC, 3.7V at 48% SOC, 4.0V at 80% SOC, and 4.2V at 100% SOC. The battery control unit32can also estimate the SOC based on the OCV per cell obtained by dividing the OCV of the entire battery pack31by the number of series of lithium-ion battery cells in the battery pack31.

The charge control map for the electrically driven vehicle3shown inFIG.4Bshows an example of changing the upper current limit according to the temperature and SOC of the battery pack31. The voltage of the battery pack31may be used instead of the SOC of the battery pack31. Alternatively, the upper current limit may be changed according to the temperature of the battery pack31without considering the SOC or voltage of the battery pack31, or the upper current limit may be changed according to the SOC or voltage of the battery pack31without considering the temperature of the battery pack31.

The initial values of the charge control map for the charger4are registered by the administrator of the charger selection system1based on the catalog specification of the charger4. Items that cannot be read from the catalog specification of the charger4may be left blank or estimated values may be registered. In the same way, the initial values of the charge control map for the electrically driven vehicle3are registered by the administrator of the charger selection system1based on the catalog specification of the battery pack31mounted in the electrically driven vehicle3.

The vehicle information acquisition unit111acquires vehicle information transmitted from the electrically driven vehicle3and registers the vehicle information in the vehicle master holding unit122. The charger information acquisition unit112acquires charger information transmitted from the charger4and registers the charger information in the charger master holding unit121.

The charging log acquisition unit113acquires the charging log transmitted from the charger4. The charge control map updating unit114estimates the charge control performed by the battery control unit32of the electrically driven vehicle3based on the vehicle ID, transition data of the SOC, temperature, and charge current command value of the battery pack31included in the acquired charging log.

In general, as the battery pack31deteriorates over time, the internal resistance thereof increases while the capacity thereof decreases. When the internal resistance rises, the heat generation increases even when the same current is applied. Many battery manufacturers incorporate a control that lowers the upper limit current used for charge control performed by the battery control unit32according to the progress of deterioration over time of the battery pack31.

The charge control map updating unit114reads the charge control map for the electrically driven vehicle3from the vehicle charge control map holding unit124based on the vehicle ID included in the acquired charging log. The charge control map updating unit114updates the read charge control map for the electrically driven vehicle3as necessary based on the estimated charge control of the electrically driven vehicle3.

More specifically, the charge control map updating unit114compares the SOC, temperature, and charge current command value of the battery pack31included in the acquired charging log with the corresponding SOC, temperature, and upper limit current of the read charge control map, and updates the upper limit current to the charge current command if the charge current command value is lower than the upper limit current.

Further, the charge control map updating unit114estimates the charge control performed by the control unit44of the charger4based on the charger ID, the output current and temperature of the charger4, and the transition data of the SOC and charge current command value of the battery pack31included in the acquired charging log.

In general, power elements used in the DC/DC converter43in the charger4, e.g., metal-oxide semiconductor field-effect transmitters (MOSFETs) and insulated gate bipolar transistors (IGBTs), deteriorate over time. Due to deterioration over time, the conversion efficiency of the power elements decreases, and the heat generation increases. Further, other elements in the charger4, e.g., electrolytic capacitors, coils, and fans, also deteriorate over time. Many charger manufacturers incorporate a control that decreases the upper current limit used for control during charging according to the progress of deterioration over time of the charger4.

The charge control map updating unit114reads the charge control map for the charger4from the charger charge control map holding unit123based on the charger ID included in the acquired charging log. The charge control map updating unit114updates the read charge control map for the charger4as necessary based on the estimated charge control of the charger4.

More specifically, the charge control map updating unit114compares the SOC of the battery pack31and the temperature and output current of the charger4with the corresponding SOC, temperature, and upper limit current of the read charge control map, and updates the upper limit current to the output current if the output current is lower than the upper limit current. The charge control map updating unit114does not update the upper limit current if the output current is lower than the upper limit current in order to satisfy the requirement of the charge current command value.

The charger search receiving unit115receives a search request for a charger4to be used for charging the electrically driven vehicle3via the network2from the electrically driven vehicle3or the operation management terminal device7. The search request from the electrically driven vehicle3includes at least the vehicle ID. The search request may further include at least one of the following information: the current position information, latitude and longitude, of the electrically driven vehicle3; a designated charging time, e.g., the shortest possible time, between XX o'clock and YY o'clock, or the like; a driving plan, e.g., a destination set in a car navigation system; and the SOC and target SOC for charging of the battery pack31.

A search request from the operation management terminal device7also includes at least the vehicle ID. The search request may further include at least one of the following information: the current position information of the electrically driven vehicle3; a designated charging time; a delivery plan; a charging plan, and the SOC and target SOC for charging of the battery pack31.

The charging time determination unit116determines the charging time based on the received search request for the charger4. If the search request includes a designated charging time, the charging time determination unit116determines the charging time to be this designated charging time. If the search request from the electrically driven vehicle3does not include a designated charging time, the charging time determination unit116determines the charging time to be the shortest. If the search request from the operation management terminal device7does not include a designated charging time or a charging plan but includes a delivery plan, the charging time determination unit116determines the charging time, charging start time and charging end time, based on the delivery plan.

If the charging time is set to the shortest by the charging time determination unit116, the charger selection unit118selects a charger4that does not limit the charging performance of the electrically driven vehicle3to be charged from among a plurality of chargers4registered in the charger master holding unit121. That is, the charger selection unit118selects a charger4having charging performance that encompasses the maximum charging performance of the electrically driven vehicle3to be charged.

If the current position information of the electrically driven vehicle3is included in the search request for the charger4, the charger selection unit118may select only chargers4located within a predetermined distance from the current position of the electrically driven vehicle3from among the plurality of chargers4registered in the charger master holding unit121as selection candidates. For example, the charger selection unit118may set only chargers4located within a radius of X km centered on the current position of the electrically driven vehicle3as the selection candidates.

The charging profile generation unit117reads charge control maps for the selection candidate chargers4from the charger charge control map holding unit123and reads the charge control map for the electrically driven vehicle3to be charged from the vehicle charge control map holding unit124. The charging profile generation unit117combines each of the charge control maps for the selection candidate chargers4and the charge control map for the electrically driven vehicle3to be charged so as to generate a charging profile for each selection candidate. More specifically, for each condition at the time of charging, the charging profile generation unit117plots the smaller of the upper limit current specified in the charge control map for a selection candidate charger4and the upper limit current specified in the charge control map for the electrically driven vehicle3to be charged.

FIG.5is a diagram showing a charging profile generated based on the charge control map for the charger A and the charge control map for the electrically driven vehicle A shown inFIGS.4A-4B. For example, for a combination of the SOC in the range of 0 to 10% and the temperature in the range of 0 to 10° C., the upper current limit of the charger A is specified as 30 [A] and that of electric vehicle A as 8 [A]. In this case, the charging profile for the same conditions is 8 [A].

The charger selection unit118refers to the respective charging profiles for the selection candidates generated by the charging profile generation unit117so as to determine whether a charger4exists that does not limit the charging performance of the electrically driven vehicle3to be charged under all conditions at the time of charging. If there is, the charger selection unit118selects the charger4as a recommended charger. If there are some, the charger selection unit118selects those chargers4as recommended chargers. If the current position information of the electrically driven vehicle3is included in the search request for the charger4, the charger selection unit118may prioritize the plurality of chargers4in order of proximity from the current position of the electrically driven vehicle3.

If there is no charger4that does not limit the charging performance of the electrically driven vehicle3to be charged in all conditions at the time of charging, the charger selection unit118selects as the recommended charger the charger4with the fewest conditions at the time of charging that limit the charging performance of the electrically driven vehicle3to be charged.

If the SOC of the battery pack31mounted in the electrically driven vehicle3is included in the search request for the charger4, the charger selection unit118may select a charger4that does not limit the charging performance of the electrically driven vehicle3based on the upper current limit of the SOC condition in the charging profile for each selection candidate. In that case, a charger4may be selected that allows for charging while both the charging performance of the charger4and the charging performance of the electrically driven vehicle3are at maximum performance.

The charger selection unit118may select a charger4that does not limit the charging performance of the electrically driven vehicle3based on the SOC and the upper limit current for the temperature condition in a charging profile for each selection candidate if atmospheric temperature information of areas where selection candidate chargers4are installed is acquired from a weather forecast server (not shown) via the network2. In that case, a charger4may be selected that allows for charging while both the charging performance of the charger4and the charging performance of the electrically driven vehicle3are at maximum performance.

The charger guidance notification unit119notifies the electrically driven vehicle3or the operation management terminal device7that requested the search for the charger4of guidance information for a recommended charger selected by the charger selection unit118. The guidance information for a recommended charger includes position information of the recommended charger.

The charger selection unit118selects as the recommended charger a charger4that can complete charging of the electrically driven vehicle3to a target SOC within a target charging time from among the plurality of registered chargers4if the current SOC and charging target SOC of the battery pack31are included in the search request of the charger4while the target charging time has been set by the charging time determination unit116.

If the current SOC is not included in the search request for the charger4, the charger selection unit118may assume that the current SOC is at 0%. If the search request for the charger4does not include a charging target SOC, the charger selection unit118may assume the charging target SOC to be at 100%.

If the current position information of the electrically driven vehicle3is included in the search request for the charger4, the charger selection unit118may select only chargers4located within a predetermined distance from the current position of the electrically driven vehicle3from among the plurality of chargers4registered in the charger master holding unit121as selection candidates.

The charger selection unit118refers to the respective charging profiles for the selection candidates generated by the charging profile generation unit117so as to select as a recommended charger a charger4that can complete charging the electrically driven vehicle3to be charged to the target SOC within the target charging time. For example, in the case of a constant current charging profile, charging can be completed within the target charging time if the current rate obtained by dividing the capacity corresponding to the difference between the target charging SOC and the current SOC by the target charging time is equal to the upper limit current or less.

The charger selection unit118may select a charger4that can complete charging within the target charging time based on the upper limit current in an SOC range at the time of charging in a charging profile for each selection candidate. The charger selection unit118may select a charger4that can complete charging within the target charging time based on the upper limit current corresponding to the combination of an SOC range at the time of charging and an expected atmospheric temperature for each charging time zone in a charging profile for each selection candidate if expected atmospheric temperature information for each charging time zone of areas where selection candidate chargers4are installed is acquired from a weather forecast server (not shown).

If there are a plurality of chargers4that can complete charging within the target charging time, the charger selection unit118selects the plurality of chargers4as recommended chargers. If the current position information of the electrically driven vehicle3is included in the search request for the charger4, the charger selection unit118may prioritize the plurality of chargers4in order of proximity from the current position of the electrically driven vehicle3. Further, the charger selection unit118may prioritize the plurality of chargers4in descending order of upper limit current for the purpose of ensuring safety at the time of charging and suppressing deterioration of the battery pack31.

If there is no charger4that can complete charging the electrically driven vehicle3to be charged within the target charging time, the charger selection unit118selects as a recommended charger the charger4that can bring the SOC of the battery pack31to be charged closest to the target SOC within the target charging time from among the selection candidate chargers4.

The charger guidance notification unit119notifies the electrically driven vehicle3or the operation management terminal device7that requested the search for the charger4of guidance information for a recommended charger selected by the charger selection unit118.

FIG.6is a flowchart showing an example of a process of updating the charge control map for the charger4and the charge control map for the electrically driven vehicle3. The charging log acquisition unit113acquires a charging log transmitted from the charger4that has finished charging the electrically driven vehicle3(S10). The charge control map updating unit114estimates charge control performed by the control unit44of the charger4from data contained in the acquired charging log (S11). The charge control map updating unit114updates as necessary the charge control map for the charger4read from the charger charge control map holding unit123based on the estimated charge control of the charger4(S12).

The charge control map updating unit114estimates charge control performed by the battery control unit32of the electrically driven vehicle3from data contained in the acquired charging log (S13). The charge control map updating unit114updates as necessary the charge control map for the electrically driven vehicle3read from the vehicle charge control map holding unit124based on the estimated charge control of the electrically driven vehicle3(S14).

FIG.7is a flowchart showing an example of a recommended charger guidance process for the fastest charging. The charger search receiving unit115receives a search request for a charger4to be used for charging the electrically driven vehicle3from the electrically driven vehicle3or the operation management terminal device7(S20). The charging profile generating unit117reads the charge control map for the electrically driven vehicle3to be charged from the vehicle charge control map holding unit124(S21). The charging profile generating unit117reads charge control maps for the plurality of selection candidate chargers4from the charger charge control map holding unit123(S22).

The charging profile generation unit117combines the charge control map for the electrically driven vehicle3to be charged and each of the charge control maps for the plurality of selection candidate chargers4so as to generate a charging profile for each selection candidate charger4(S23). The charger selection unit118refers to the respective charging profiles generated for the selection candidates and selects a charger4that does not limit the charging performance of the electrically driven vehicle3to be charged under predicted conditions at the time of charging as a recommended charger (S24). The charger guidance notification unit119notifies the electrically driven vehicle3or the operation management terminal device7that requested the search of guidance information for the selected recommended charger (S25).

FIG.8is a flowchart showing an example of a recommended charger guidance process for non-fastest charging. The charger search receiving unit115receives a search request for a charger4to be used for charging the electrically driven vehicle3from the electrically driven vehicle3or the operation management terminal device7(S30). The charging time determination unit116determines the charging time based on various types of information included in the received search request for the charger4(S31).

The charging profile generating unit117reads the charge control map for the electrically driven vehicle3to be charged from the vehicle charge control map holding unit124(S32). The charger selection unit118narrows down the selection candidates from among the plurality of chargers4registered in the charger master holding unit121to chargers4located within a predetermined distance from the current position of the electrically driven vehicle3(S33). The charging profile generating unit117reads charge control maps for the plurality of selection candidate chargers4from the charger charge control map holding unit123(S34).

The charging profile generation unit117combines the charge control map for the electrically driven vehicle3to be charged and each of the charge control maps for the plurality of selection candidate chargers4so as to generate a charging profile for each selection candidate charger4(S35). The charger selection unit118refers to the respective charging profiles generated for the selection candidates and selects a charger4that can complete charging to the target SOC within a determined charging time as a recommended charger (S36). The charger guidance notification unit119notifies the electrically driven vehicle3or the operation management terminal device7that requested the search of guidance information for the selected recommended charger (S37).

There are some charging stations that have multiple chargers4connected to a single distribution board connected to the commercial power system6. Also, some models have a single charger4with multiple charging ports. Hereafter, in the present specification, a charger4with multiple DC/DC converters43in parallel in the housing of one charger4and with multiple charging ports is also treated as multiple chargers4.

FIG.9is a diagram showing a configuration in which two chargers4are connected to one distribution board8. For example, a maximum of 30 A current can be drawn from the distribution board8when one charger4is used to charge one electrically driven vehicle3if the allowable current of a breaker in the distribution board8is 30 A. In contrast, the current that each charger4can draw from the distribution board8drops to a maximum of 15 A when two chargers4are used to charge two electrically driven vehicles3simultaneously.

FIG.10is a diagram showing a charging profile obtained when the two chargers are connected that is generated based on the charge control map for the charger A and the charge control map for the electrically driven vehicle A shown inFIGS.4A-4B. The charging profile inFIG.5shows the charging profile obtained when one charger is connected. In the charging profile inFIG.10, the upper current limit for the combination of an SOC in the range of 0 to 10% and a temperature in the range of 10 to 45° C. and the upper current limit for the combination of an SOC in the range of 10 to 48% and a temperature in the range of 10 to 45° C. are each limited to 15 [A].

The charging profile generation unit117generates a charging profile for each number of chargers to be used if at least two chargers4are connected to the commercial power system6via a single breaker. According to a predicted number of chargers to be used, the charger selection unit118switches the charging profile to be referred to for at least two chargers4connected to one breaker. That is, when selecting a recommended charger, the charger selection unit118uses the upper limit current according to the predicted number of chargers to be used for at least two chargers4connected to a single breaker.

For example, for practical use, the predicted number of chargers to be used during the daytime may be fixed to one, and the predicted number of chargers to be used during the nighttime may be fixed to two. The charger selection unit118may determine the predicted number of chargers to be used based on charging plans for multiple chargers4connected to one breaker if the charging plans can be acquired.

As explained above, according to the present embodiment, it is possible to appropriately select a charger4to be used for charging a specific electrically driven vehicle3from among a plurality of chargers4. An electrically driven vehicle3cannot be charged as planned if a charger4cannot meet the current requirement of an electrically driven vehicle3. In this regard, according to the present embodiment, selection of a charger4that does not limit the charging performance of the electrically driven vehicle3allows the electrically driven vehicle3to be charged as planned. Further, even if there is no charger4that can charge the electrically driven vehicle3as planned, a charger4that can achieve charging in a way close to the plan can be selected as an alternative.

Estimation of the charging performance of a charger4and the charging performance of an electrically driven vehicle3using a charging log and updating of the charge control map for the charger4and the charge control map for the electrically driven vehicle3allow for matching based on the actual charging performance. In contrast, when matching of a charger4and an electrically driven vehicle3is performed based on catalog specifications of the charger4and electrically driven vehicle3, a charger4that cannot perform charging as required by the electrically driven vehicle3may be selected due to the discrepancy between the catalog specifications and the actual performance of the charger4and the deterioration of the charger4. In this case, the charging time is longer than expected.

The detailed charge control of the charger4and electrically driven vehicle3is treated as a black box by each manufacturer, and it is difficult to identify the detailed charge control from catalog specifications. In contrast, the charge control of the charger4and electrically driven vehicle3can be estimated with high accuracy by learning the charge control of the charger4and electrically driven vehicle3from the charging log in the present embodiment.

The charging performance of a charger4also depends on the quality of power supplied from the commercial power system6. Since charging logs obtained when the quality of the power from the commercial power system6is poor are also learned, the number of cases where charging cannot be performed as planned due to the influence of the commercial power system6can be reduced.

With the rapid spread of chargers4in the future, it is expected that inexpensive low-performance products will appear on the market. In addition, it is expected that the number of chargers4will increase that are no longer able to output power as shown in the specifications due to aging. Furthermore, the charging performance of electrically driven vehicles3is expected to improve as battery packs31mounted in the electrically driven vehicles3become larger in capacity and the number of vehicle models compatible with rapid charging increases. Thus, it is expected that the number of chargers4that cannot meet the requirements of electrically driven vehicles3will increase in the future.

In the present embodiment, the optimal matching of a charger4and an electrically driven vehicle3can be achieved by also considering the degradation of charging performance on the electrically driven vehicle3side. The charging performance of both can be utilized without excess or deficiency if a combination that can bring out the maximum performance of both can be extracted. This contributes to the efficient operation of all chargers4registered in the charger selection system1.

In the present embodiment, the effects of individual differences in chargers4and the current limitation by a breaker between the chargers4and the commercial power system6can be taken into account, and more optimal matching of chargers4and electric vehicles3can thus be achieved.

Further, in the present embodiment, it is possible to select a charger4that can perform charging according to the planned charging time even when low-current charging is performed from the viewpoint of ensuring safety during charging and suppressing deterioration of the battery pack31.

Described above is an explanation based on the embodiments of the present disclosure. The embodiments are intended to be illustrative only, and it will be obvious to those skilled in the art that various modifications to constituting elements and processes could be developed and that such modifications are also within the scope of the present disclosure.

In the above embodiment, the charge control map for a charger4and the charge control map for a charged electrically driven vehicle3are updated based on the charging log obtained from the charger4. In this regard, only the charge control map for the charger4may be updated based on the charging log. That is, the charge control map for the electrically driven vehicle3may have a fixed value, e.g., a value that can be read from the catalog specifications.

Further, the charger4may also transmit to the charger selection system1the charging log of the electrically driven vehicle3that is not registered in the vehicle master holding unit122. In that case, only the charge control map for the charger4is updated based on the charging log.

Four-wheeled electric vehicles are assumed as electrically driven vehicles3in the above embodiment. In this regard, electric motorcycles (electric scooters), electric bicycles, and electric kick scooters may also be used. Further, the electrically driven vehicles include not only full-standard electric vehicles but also low-speed electric vehicles such as golf carts and land cars used in shopping malls and entertainment facilities.

The embodiment may be specified by the following items.

A charger selection system (1) including:a first charge control map holding unit (123) that holds a charge control map for a plurality of chargers (4);a second charge control map holding unit (124) that holds a charge control map for a plurality of electrically driven vehicles (3); anda charger selection unit (118) that selects a charger (4) used for charging any one electrically driven vehicle (3) of the plurality of electrically driven vehicles (3) from among the plurality of chargers (4),wherein a charge control map for a plurality of chargers (4) specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the chargers (4), the state of charge (SOC) of a secondary battery (31) mounted in an electrically driven vehicle (3) to be charged, the voltage of the secondary battery (31), and time,wherein a charge control map for the electrically driven vehicle (3) specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the secondary battery (31), the SOC of the secondary battery (31), the voltage of the secondary battery (31), and time, andwherein the charger selection unit (118) selects at least one charger (4) that least limits the charging performance of the electrically driven vehicle (3) to be charged.

This allows a charger (4) to be selected that can perform charging as planned according to the electrically driven vehicle (3).

The charger selection system (1) according to Item 1,wherein the charge control map for the charger (4) specifies an upper limit current according to the temperature of the charger (4), an upper limit current according to the SOC or voltage of the secondary battery (31) mounted in the electrically driven vehicle (3) to be charged, or an upper limit current according to a combination of the temperature of the charger (4) and the SOC or voltage of the secondary battery (31), andwherein the charge control map for the electrically driven vehicle (3) specifies an upper limit current according to the temperature of the secondary battery (31), an upper limit current according to the SOC or voltage of the secondary battery (31), or an upper limit current according to a combination of the temperature of the secondary battery (31) and the SOC or voltage of the secondary battery (31).

This allows a charger (4) to be selected that can perform charging as planned according to the electrically driven vehicle (3).

The charger selection system (1) according to Item 1 or 2, wherein the charger selection unit (118) selects a charger (4) that does not limit the charging performance of the electrically driven vehicle (3) under predicted conditions at the time of charging.

This can increase the probability that a charger (4) is selected that can perform charging as planned according to the electrically driven vehicle (3).

The charger selection system (1) according to any one of Items 1 through 3, further including:a charging log acquisition unit (113) that acquires a charging log from any one charger (4) of the plurality of chargers (4); anda charge control map updating unit (114) that updates a charge control map held in the first charge control map holding unit (123) based on the acquired charging log.

According to this, the actual state of the charging performance of the charger (4) can be reflected in the charge control map.

The charger selection system (1) according to Item 4, wherein the charge control map updating unit (114) further updates a charge control map held in the second charge control map holding unit (124) based on the acquired charging log.

According to this, the actual state of the charging performance of the electrically driven vehicle (3) can be reflected in the charge control map.

The charger selection system (1) according to any one of Items 1 through 5, further including:a charging time determination unit (116) that determines a charging time based on information included in a search request for a charger (4),wherein the charger selection unit (118) selects a charger (4) that completes targeted charging within the determined charging time from among the plurality of chargers (4) when the charging time has been determined by the charging time determination unit (116).

This allows a charger (4) to be selected that can perform charging according to a charging plan even when the fastest charging is not performed.

The charger selection system (1) according to any one of Items 1 through 6, wherein when at least two chargers (4) are connected to a power system (6) via one breaker (8), the charger selection unit (118) uses for the upper limit current of the at least two chargers (4) an upper limit current according to a predicted number of chargers to be used.

According to this, a connection mode between the chargers (4) and the power system (6) can be reflected in the charger (4) selection.

A charger selection method including:referring to a charge control map for a plurality of chargers (4) that specifies the relationship between an upper limit current and charging conditions including at least the temperature of the chargers (4) or at least one of the temperature of the chargers (4), the state of charge (SOC) of a secondary battery (31) mounted in an electrically driven vehicle (3) to be charged, the voltage of the secondary battery (31), and time and a charge control map for a plurality of electrically driven vehicles (3) that specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the secondary battery (31), the SOC of the secondary battery (31), the voltage of the secondary battery (31), and time so as to select a charger (4) used for charging any one electrically driven vehicle (3) of the plurality of electrically driven vehicles (3) from among the plurality of chargers (4); andselecting at least one charger (4) that least limits the charging performance of the electrically driven vehicle (3) to be charged in the selecting of a charger (4).

This allows a charger (4) to be selected that can perform charging as planned according to the electrically driven vehicle (3).

A charger selection program comprising computer-implemented modules including:a module that refers to a charge control map for a plurality of chargers (4) that specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the chargers (4), the state of charge (SOC) of a secondary battery (31) mounted in an electrically driven vehicle (3) to be charged, the voltage of the secondary battery (31), and time and a charge control map for a plurality of electrically driven vehicles (3) that specifies the relationship between an upper limit current and charging conditions including at least one of the temperature of the secondary battery (31), the SOC of the secondary battery (31), the voltage of the secondary battery (31), and time so as to select a charger (4) used for charging any one electrically driven vehicle (3) of the plurality of electrically driven vehicles (3) from among the plurality of chargers (4); anda module that selects at least one charger (4) that least limits the charging performance of the electrically driven vehicle (3) to be charged in the module that selects a charger (4).

This allows a charger (4) to be selected that can perform charging as planned according to the electrically driven vehicle (3).

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to the selection of a charger for an electrically driven vehicle.

REFERENCE SIGNS LIST