Vehicle, vehicle control system and vehicle control method

Abstract

Vehicle with a battery pack (10) containing a secondary battery, a battery sensor (12) which detects a state of the secondary battery, and a first control device, a second control device provided separately from the battery pack (10), a converter, where the first control device is arranged to use a detection value of the battery sensor (12) to obtain a current upper limit value indicating an upper limit of an output current of the secondary battery, the second control device is configured to use a power upper limit value indicating an upper limit of an output power of the secondary battery to control the output power of the secondary battery, and the converter is configured to convert the current upper limit value into the power upper limit value by multiplying an estimated voltage value by the current upper limit value, wherein the estimated voltage value is a voltage value of the secondary battery in a state in which a current corresponding to the current upper limit value flows, and a third control device which is provided separately from the battery pack (10) and is arranged to relay a communication between the first control device and the second control device, wherein the converter is attached to the third control device, the battery pack (10) is set up to output the upper current limit value, the vehicle is configured such that when the current upper limit value from the battery pack (10) is input to the third control device, the converter converts the current upper limit value into the power upper limit value and the power upper limit value is output from the third control device to the second control device, and the third control device is configured to perform the conversion and output the power upper limit value when the current upper limit value is input, and to output the power upper limit value without performing the conversion when the power upper limit value is input.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present disclosure relates to a vehicle, a vehicle control system, and a vehicle control method.2. DESCRIPTION OF THE RELATED ARTJapanese Unexamined Patent Application Publication JP 2019-156 007 A discloses a controller that controls an output of a secondary battery using an upper limit power value (Wout) indicating an upper limit output of the secondary battery mounted on a vehicle.US 2014 / 0 111 164 A1 discloses a battery control device capable of accurately obtaining the allowable charging or discharging power according to the variation of the internal resistance of a battery. The battery control device includes an internal resistance table in which the internal resistance value of individual cells is described according to the temperature and the state of charge thereof in association with each charging or discharging period of the individual cells. The battery control device calculates an allowable charging current or an allowable discharging current using the internal resistance value described in the internal resistance table, and controls the charging or discharging of the individual cells according to the current value thus obtained.JP 2014-58 267 A discloses a vehicle power generation control system in which an MPU of a generation ECU obtains load information on an operating state of the onboard device via a communication medium such as an onboard power supply system, and calculates a power demand of a vehicle based on the load information. Further, the MPU determines whether a charge initiation condition can be established based on an index value of a currently remaining chargeable capacity of a battery and the calculated value of power demand. As long as the calculated value of the power demand is larger but not relatively small as the index value of the current remaining chargeable capacity of the battery is larger, the charge initiation condition is established. Further, the MPU controls an alternator until a charge termination condition is established, and thus performs the charging of the battery to be performed by the alternator.DE 10 2018 127 530 A1 discloses a method for predicting the performance of a battery pack in a system. The method includes determining, via a controller, an open circuit voltage of the battery pack, calculating the pack resistance using the measured voltage and current during a charging or discharging event, and calculating a maximum current of the pack using the open circuit voltage and internal resistance. The method includes selecting the lower or an absolute value of each of the calculated maximum discharge current and the predetermined current limit, calculating the discharge capacity of the battery pack using the selected lower absolute value, and controlling a state of the system using the calculated performance. The method also controls the charging current and parameters during a DC fast charging operation. A system includes the battery pack, the electric machine, and the controller. The system may be a vehicle having an electric powertrain with an electric machine powered by the battery pack.SUMMARY OF THE INVENTIONElectric powered vehicles (for example, electric vehicles or hybrid vehicles) using a secondary battery as a power source are becoming more and more prevalent. In the electrically driven vehicles, when the capacity or the output of the secondary battery decreases due to battery deterioration or the like, it is conceivable that the secondary battery mounted on the electrically driven vehicle is replaced.Generally, the secondary battery is mounted on a vehicle in the form of a battery pack. The battery pack includes a secondary battery, a sensor that detects the state of the secondary battery (for example, current, voltage, and temperature), and a controller. Hereinafter, the control device included in the battery pack is also referred to as a "battery electronic control unit (battery ECU)", and the sensor included in the battery pack is also referred to as a "battery sensor". Peripheral devices (for example, a sensor and a controller) suitable for the secondary battery are mounted on the battery pack. The battery pack is stored such that the secondary battery and its peripheral devices can operate normally. Therefore, when replacing the vehicle-mounted secondary battery, it is considered preferable from the viewpoint of vehicle maintenance to replace not only the secondary battery but the entire vehicle-mounted battery pack.As described in JP 2019-156 007 A, there is a known control device that is mounted on a vehicle separately from a battery pack and that controls the output of the secondary battery using an upper limit power value (hereinafter also referred to as "power limit control device"). The power constraint controller is configured to perform a power-based output constraint. The power-based output limitation is a process of controlling the output of the secondary battery such that the output of the secondary battery does not exceed the power upper limit value. In general, a vehicle including a controller that performs the power-based output restriction is equipped with a battery pack including a battery ECU that obtains a power upper limit value by using a detection value from a battery sensor (hereinafter also referred to as a "power restriction battery pack").On the other hand, a controller that is mounted on a vehicle separately from the battery pack and that controls the output current of the secondary battery using an upper limit current value indicating an upper limit value of the output current of the secondary battery (hereinafter also referred to as "current restriction control means") is known. The current restriction control means is arranged to perform a current-based output restriction. The current-based output limitation is a process of controlling the output current of the secondary battery such that the output current of the secondary battery does not exceed an upper limit current value. In general, a vehicle including a controller that performs the current-based output restriction is equipped with a battery pack including a battery ECU that obtains a current upper limit value using a detection value from a battery sensor (hereinafter also referred to as "current restriction battery pack").Depending on the supply situation and the need (or the storage status) of the battery pack, the current limiting battery pack can be used more easily than the power limiting battery pack. However, with respect to the related art vehicle, it has not been expected to use a current limiting battery pack and a power limiting controller in combination, and thus studies on means for using a current limiting battery pack and a power limiting controller in combination have not been performed. Therefore, it is difficult to apply a current limiting battery pack in a vehicle equipped with a power limiting control device.An object of the present invention is to enable performance of power-based output restriction on a secondary battery included in a current restriction battery pack.The object is achieved by the features of the independent claims. Advantageous refinements of the invention are described in the dependent claims.A vehicle according to a first aspect of the present disclosure includes a battery pack including a first controller, and a second controller and a converter provided separately from the battery pack. The battery pack further includes a secondary battery and a battery sensor that detects a state of the secondary battery. The first controller is configured to use a detection value of the battery sensor to obtain an upper limit current value indicating an upper limit value of an output current of the secondary battery. The second controller is configured to use an upper limit power value indicating an upper limit power value of the secondary battery to control the output power of the secondary battery. The converter is configured to perform conversion of the current upper limit value to the power upper limit value by performing multiplication of a voltage value of the secondary battery in a state where a current corresponding to the current upper limit value flows (hereinafter referred to as an "estimated voltage value") with the current upper limit value.The vehicle is equipped with the converter that converts the current upper limit value into the power upper limit value. The voltage of the secondary battery changes depending on the magnitude of the current. The converter uses the estimated voltage value (i.e., the voltage value of the secondary battery in the state where the current corresponding to the current upper limit value flows) to convert the current upper limit value to the power upper limit value. Specifically, the converter converts the current upper limit value to the power upper limit value by multiplying the current upper limit value by the estimated voltage value. This makes it possible to obtain the power upper limit value corresponding to the current upper limit value with high accuracy. With the above configuration, the second controller can suitably perform power-based output restriction even when the current restriction battery pack is applied. The second control means corresponds to the above-described power restriction control means.In the above configuration, the converter may be configured to use measured values of a current and a voltage of the secondary battery detected by the battery sensor, an internal resistance of the secondary battery, and the current upper limit value to obtain the estimated voltage value.The converter having the above configuration can securely and appropriately obtain the estimated voltage value. Then, the converter can convert the current upper limit value to the power upper limit value with high accuracy by using the estimated voltage value obtained as described above. Hereinafter, the measured values of the current and the voltage of the secondary battery detected by the battery sensor are also referred to as "actual current" and "actual voltage". The current, voltage, and internal resistance of the secondary battery have a relationship represented by "internal resistance=voltage / current". The internal resistance of the secondary battery used for obtaining the estimated voltage value may be stored in a storage device in advance. The internal resistance of the secondary battery stored in the storage device may be a fixed value or may be variable according to the temperature of the secondary battery. The converter described above may obtain the estimated voltage value based on the actual current, the actual voltage, the current upper limit value, and the internal resistance according to an expression "estimated voltage value=actual voltage+(current upper limit value-actual current)×intermittence.".In the above configuration, the vehicle further includes a third controller provided separately from the battery pack and configured to relay communication between the first controller and the second controller. The converter is mounted on the third controller. The battery pack is configured to output the current upper limit value. The vehicle is configured such that when the current upper limit value is input from the battery pack to the third controller, the converter performs the conversion of the current upper limit value to the power upper limit value, and the power upper limit value is output from the third controller to the second controller.In the above configuration, the third controller provided separately from the battery pack includes the converter, and the converter converts the current upper limit value to the power upper limit value. The inverter can thus be mounted on the vehicle without changing the configurations of the battery pack (including the first controller) and the second controller.In the above configuration, the third controller is configured to perform the conversion and output of the power upper limit value when the current upper limit value is input, and to output the power upper limit value without performing the conversion when the power upper limit value is input.According to the above configuration, when the vehicle is equipped with the current limiting battery pack, the third controller performs the conversion on the current upper limit value input from the current limiting battery pack and outputs the power upper limit value. On the other hand, when the vehicle is equipped with the power limiting battery pack, the third controller outputs the current upper limit value without performing the conversion on the power upper limit value input from the power limiting battery pack. With the above configuration, therefore, the second controller can suitably perform the power-based output restriction both in a case where the power restriction battery pack is applied and in a case where the power restriction battery pack is applied.In the above configuration, the first controller, the second controller, and the third controller may each be a microcomputer connected to a local area network (LAN) in the vehicle. In the in-vehicle LAN, the first controller may be connected via the third controller to the second controller for communicating with the second controller via the third controller.Note that LAN is an abbreviation for "Local Area Network". In the above configuration, each of the first to third control devices is a microcomputer. The microcomputer is small in size and has a large processing capacity, and thus is suitable as an in-vehicle control device. The third controller may receive the current upper limit value from the first controller via the in-vehicle LAN, convert the current upper limit value to the power upper limit value with the converter, and then transmit the power upper limit value to the second controller via the in-vehicle LAN. With the above configuration, each controller can suitably perform the required calculation and communication. As the communication protocol of the in-vehicle LAN, a controller area network (CAN) or FlexRay may be adopted.The third controller may also be used for purposes other than the conversion of the upper limit value (i.e., conversion from the current upper limit value to the power upper limit value). The third controller may be configured to control information (for example, accumulating vehicle data). Further, the third controller may operate as a central gateway (CGW).In the above configuration, the converter may be mounted on the first controller. The first controller may be configured to perform the conversion of the current upper limit value obtained using the detection value of the battery sensor with the converter to the power upper limit value and output the power upper limit value to the second controller when the first controller is connected to the second controller.The converter may be incorporated in the first controller (i.e., the battery pack). With this configuration, the current upper limit value in the battery pack may be converted into the power upper limit value, and the power upper limit value may be output from the battery pack. Thus, the second controller can suitably perform the power-based output restriction without adding the third controller.In the above configuration, the converter may be mounted on the second controller. The battery pack may be configured to output the current upper limit value. The second controller may be configured to perform the conversion of the current upper limit value input from the battery pack with the converter into the power upper limit value and to control the output of the secondary battery such that the output of the secondary battery does not exceed the power upper limit value.In the above configuration, the second controller provided separately from the battery pack includes the converter, and the converter converts the current upper limit value to the power upper limit value. Therefore, the converter can be mounted on the vehicle without changing the configuration of the battery pack (including the first controller). Further, the second controller may suitably perform the power-based output restriction without adding the third controller.The vehicle of the above configuration may be an electrically driven vehicle that travels using electric power stored in the secondary battery in the battery pack. The electric powered vehicle includes an electric vehicle (EV), a hybrid vehicle (HV), and a plug-in hybrid vehicle (PHV).The vehicle may be a hybrid vehicle including a first motor generator, a second motor generator, and an engine. Electric power can be supplied to the first motor generator and the second motor generator from the secondary battery in the battery pack, respectively. The engine and the first motor generator may be mechanically connected to drive wheels of the hybrid vehicle via a single ring planetary gear. The single ring planetary gear and the second motor generator may be configured such that the driving force output from the single ring planetary gear and the driving force output from the second motor generator are combined and transmitted to the driving wheels. The second controller may generate a control command for each of the first motor generator, the second motor generator, and the engine such that the output of the secondary battery does not exceed the upper limit power value.In a vehicle control system according to a second aspect of the present disclosure, the power upper limit value corresponding to the current upper limit value is obtained by multiplying the current upper limit value by the estimated voltage value. Therefore, even when the current limiting battery pack is applied, it is possible to suitably perform the power-based output limiting on the secondary battery included in the current limiting battery pack.In a vehicle control method according to a third aspect of the present disclosure, the power upper limit value corresponding to the current upper limit value is obtained by multiplying the current upper limit value by the estimated voltage value. Therefore, even when the current limiting battery pack is applied, it is possible to suitably perform the power-based output limiting on the secondary battery included in the current limiting battery pack.The above configuration enables provision of a vehicle, a vehicle control system, and a vehicle control method that can perform power-based output restriction on a secondary battery included in a current restriction battery pack.BRIEF DESCRIPTION OF THE DRAWINGSHereinafter, features, advantages, and technical and industrial significance of embodiments of the invention will be described with reference to the accompanying drawings, in which like reference numerals denote like components. FIG. 1 is a diagram illustrating a configuration of a vehicle according to an exemplary embodiment of the present disclosure, FIG. 2 is a diagram illustrating a connection mode of control devices included in the vehicle according to the embodiment of the present disclosure, FIG. 3 is a diagram showing an example of a map used for setting target battery power in the vehicle according to the embodiment of the present disclosure, FIG. 4 is a diagram showing a detailed configuration of a battery pack, a gateway electronic control unit (gateway ECU), and a hybrid vehicle (HV)ECU shown in FIG. 1 , FIG. 5 is a diagram showing a detailed configuration of a conversion unit shown in FIG. 4, FIG. 6 is a diagram for describing a method of obtaining an estimated voltage value according to the embodiment of the present disclosure, FIG. 7 is a diagram showing a first example of a vehicle control system according to the embodiment of the present disclosure, FIG. 8 is a diagram showing a second example of the vehicle control system according to the embodiment of the present disclosure, FIG. 9 is a diagram showing a modified example of the gateway ECU shown in FIG. 4, FIG. 10 is a diagram showing a modified example of the HV ECU shown in FIG. 4, FIG. 11 is a diagram showing a first modified example of the vehicle control system shown in FIG. 4; and FIG. 12 is a diagram showing a second modified example of the vehicle control system shown in FIG. 4.DETAILED DESCRIPTION OF THE EMBODIMENTSEmbodiments of the present disclosure will be described in more detail with reference to the drawings. Note that the same or corresponding portions in the drawings are denoted by the same reference numerals, and their repeated description is omitted. Hereinafter, an electronic control unit is also referred to as an "ECU".FIG. 1 is a diagram showing a configuration of a vehicle according to this embodiment. In this embodiment, it is assumed that a front-wheel-drive four-wheel vehicle (specifically, a hybrid vehicle) is used, but the number of wheels and the drive system may be changed as appropriate. For example, the drive system may be a four-wheel drive.Referring to FIG. 1, a vehicle 100 is equipped with a battery pack 10 including a battery ECU 13. Further, a motor ECU 23, an engine ECU 33, an HV ECU 50, and a gateway ECU 60 are mounted on the vehicle 100 separately from the battery pack 10. The motor ECU 23, the engine ECU 33, the HV ECU 50, and the gateway ECU 60 are located outside the battery pack 10. the battery ECU 13 is located in the battery pack 10.The battery pack 10 includes a battery 11, a voltage sensor 12 a, a current sensor 12 b, a temperature sensor 12 c, the battery ECU 13, and a system main relay (SMR) 14. In this embodiment, a assembled battery including a plurality of electrically connected lithium ion batteries is adopted as the battery 11. Each secondary battery constituting the assembled battery is also referred to as a "cell". In this embodiment, each lithium ion battery constituting the battery 11 corresponds to the "cell". The secondary battery included in the battery pack 10 is not limited to the lithium ion battery, and may be another secondary battery (for example, a nickel metal hydride battery). An electrolytic solution secondary battery or an all-solid secondary battery may be used as a secondary battery.The voltage sensor 12 adetects the voltage of each cell of the battery 11. the current sensor 12 bdetects current flowing through the battery 11 (the charge side takes a negative value). The temperature sensor 12 cdetects the temperature of each cell of the battery 11. The current sensor 12 bis provided on the current path of the battery 11. In this embodiment, a voltage sensor 12a and a temperature sensor 12c are provided for each cell. However, the present disclosure is not limited thereto, and a voltage sensor 12 aand a temperature sensor 12 cmay be provided for each group of a plurality of cells, or only a voltage sensor 12 aand a temperature sensor 12 cmay be provided for a assembled battery. Hereinafter, the voltage sensor 12 a, the current sensor 12 b, and the temperature sensor 12 care collectively referred to as "battery sensor 12". The battery sensor 12 may be a battery management system (BMS) having a state of charge (SOC) estimator, a state of health (SOH) estimator, a cell voltage compensation function, a diagnostic function, and a communication function in addition to the above sensor functions.The SMR 14 is configured to switch connection and disconnection of power paths that connect external connection terminals T 1 and T 2 of the battery pack 10 and the battery 11. An electromagnetic mechanical relay may be used as the SMR 14, for example. In this embodiment, a power control unit (PCU) 24 is connected to the external connection terminals T 1 and T 2 of the battery pack 10. The battery 11 is connected to the PCU 24 via the SMR 14. When the SMR 14 is in the closed state (connected state), power can be transmitted between the battery 11 and the PCU 24. On the other hand, when the SMR 14 is in the open state (disconnected state), the power paths connecting the battery 11 and the PCU 24 are disconnected. In this embodiment, the SMR 14 is controlled by the battery ECU 13. The battery ECU 13 controls the SMR 14 according to an instruction from the HV ECU 50. The SMR 14 is in the closed state (connected state), for example, when the vehicle 100 travels.The vehicle 100 includes an internal combustion engine 31, a first motor generator 21 a(hereinafter referred to as "MG 21 a"), and a second motor generator 21 b(hereinafter referred to as "MG 21 b") as power sources for traveling. The MG 21 aand the MG 21 bare motor generators having both a function as a motor that outputs torque by receiving drive power and a function as a generator that generates electric power by receiving the torque. An alternating current (AC) motor (for example, a permanent magnet synchronous motor or an induction motor) is used as the MG 21a and the MG 21b. The MG 21 aand the MG 21 bare electrically connected to the battery 11 via the PCU 24. The MG 21 aincludes a rotor axis 42 a, and the MG 21 bincludes a rotor axis 42 b. The rotor axis 42 acorresponds to a rotation shaft of the MG 21 a, and the rotor axis 42 bcorresponds to a rotation shaft of the MG 21 b.The vehicle 100 further includes a single ring planetary gear 42, and an output shaft 41 of the engine 31 and the rotor axis 42 aof the MG 21 aare connected to the single ring planetary gear 42. The internal combustion engine 31 is, for example, a spark ignition internal combustion engine including a plurality of cylinders (for example, four cylinders). The internal combustion engine 31 burns fuel (for example, gasoline) in each cylinder to generate driving force, and the generated driving force rotates a crankshaft (not shown) used by all the cylinders. The crankshaft of the engine 31 is connected to the output shaft 41 via a rotary damper (not shown). The output shaft 41 rotates together with the rotation of the crankshaft. The internal combustion engine 31 is not limited to a gasoline engine, and may be a diesel engine.The single ring planetary gear 42 has three rotational components, i.e., an input component, an output component, and a reaction force component. Specifically, the single ring planetary gear 42 includes a sun gear, a ring gear disposed coaxially with the sun ring, a gear engaged with the sun ring and the ring gear, and a carrier that holds the gear so that the gear can rotate and revolve. The carrier corresponds to the input component, the ring gear corresponds to the output component, and the sun gear corresponds to the reaction force component.The engine 31 and the MG 21 aare mechanically connected to each other via the single ring planetary gear 42. The output shaft 41 of the internal combustion engine 31 is connected to the carrier of the single ring planetary gear 42. The rotor axis 42 aof the MG 21 ais connected to the sun ring of the single ring planetary gear 42. The torque output from the engine 31 is input to the carrier. The single ring planetary gear 42 is configured to split the torque output from the engine 31 to the output shaft 41 into a torque transmitted to the sun gear (finally, the MG 21 a) and a torque transmitted to the ring gear. When the torque output from the engine 31 is output to the ring gear, the reaction torque generated by the MG 21 aapplies to the sun gear.The single-ring planetary gear set 42 and the MG 21 bare configured such that the driving force output from the single-ring planetary gear set 42 (i.e., driving force output to the ring gear) and the driving force output from the MG 21 b(i.e., driving force output to the rotor shaft 42 b) are combined and transmitted to the driving wheels 45 aand 45 b. Specifically, an output gear (not shown) engaged with a driven gear 43 is mounted on the ring gear of the single ring planetary gear 42. A drive gear (not shown) mounted on the rotor shaft 42 bof the MG 21 bis also meshed with the driven gear 43. The driven gear 43 combines the torque output from the MG 21 bto the rotor axis 42 band the torque output from the ring gear of the single ring planetary gear 42. The thus combined driving torque is transmitted to a differential gear 44 and further transmitted to the driving wheels 45a and 45b via driving shafts 44a and 44b extending rightward and leftward from the differential gear 44.The MG 21 ais provided with a motor sensor 22 athat detects the state (for example, current, voltage, temperature, and rotational speed) of the MG 21 a. The MG 21 bis provided with a motor sensor 22 bthat detects the state (for example, current, voltage, temperature, and rotational speed) of the MG 21 b. The engine sensors 22 aand 22 boutput their detection results to the engine ECU 23. The engine 31 is provided with an engine sensor 32 that detects the state of the engine 31 (for example, intake air amount, intake pressure, intake temperature, exhaust pressure, exhaust temperature, catalyst temperature, engine cooling liquid temperature, and rotational speed). The engine sensor 32 outputs its detection result to the engine ECU 33.The HV ECU 50 is configured to issue a command (control command) for controlling the engine 31 to the engine ECU 33. The engine ECU 33 is configured to control various actuators of the engine 31 (for example, a throttle valve, an igniter, and an injector (not shown)) according to the command from the HV ECU 50. The HV ECU 50 may perform engine control via the engine ECU 33.The HV ECU 50 is configured to issue a command (control command) for controlling the MG 21 aand the MG 21 bto the motor ECU 23, respectively. The motor ECU 23 is configured to generate current signals (for example, signals indicating amplitude and frequency of current) that match the target torque of each of the MG 21 aand the MG 21 bin accordance with the command from the HV ECU 50 and output the generated current signals to the PCU 24. The HV ECU 50 may perform motor control via the motor ECU 23.The PCU 24 includes, for example, two inverters respectively corresponding to the MG 21 aand the MG 21 b, and an inverter (not shown) disposed between each inverter and the battery 11. The PCU 24 is configured to supply electric power accumulated in the battery 11 to the MG 21 aand the MG 21 b, respectively, and supply electric power generated by the MG 21 aand the MG 21 b, respectively, to the battery 11. The PCU 24 is configured such that the states of the MG 21 aand the MG 21 bcan be controlled separately, and the MG 21 bmay be in the power flow state while the MG 21 ais in the regenerative state (i.e., the power generation state), for example. The PCU 24 is configured to be able to supply the electric power generated by one of the MG 21 aand the MG 21 bto the other generator. The MG 21 aand the MG 21 bare configured to be able to transmit and receive electric power to and from each other.The vehicle 100 is configured to perform hybrid vehicle (HV) driving and electric vehicle (EV) driving. The HV traveling is traveling performed by operating the engine 31 and the MG 21 b, where the engine 31 generates driving force for traveling. The EV travel is travel performed by operating the MG 21 bwhen the internal combustion engine 31 is stopped. When the internal combustion engine 31 is stopped, no combustion is performed in the cylinders. When the combustion in the cylinders is stopped, the internal combustion engine 31 does not generate combustion energy (driving force for traveling). The HV ECU 50 is configured to switch between the EV travel and the HV travel depending on the situation.FIG. 2 is a diagram showing a connection mode of the control devices included in the vehicle 100 according to this embodiment. Referring to FIG. 2 along with FIG. 1, the vehicle 100 includes an in-vehicle local area network (LAN) including a local bus B 1 and a global bus B 2. The control devices (for example, the battery ECU 13, the motor ECU 23, and the engine ECU 33) mounted on the vehicle 100 are connected to the in-vehicle LAN. In this exemplary embodiment, a control unit network (CAN) is used as the communication protocol of the LAN in the vehicle. The local bus B 1 and the global bus B 2 are, for example, CAN buses. However, the communication protocol of the in-vehicle LAN is not limited to the CAN, and may be any protocol such as FlexRay.The battery ECU 13, the motor ECU 23, and the engine ECU 33 are connected to the local bus B 1. Although not shown, a plurality of controllers are connected to the global bus B2. The controllers connected to the global bus B2 include, for example, a human machine interface (HMI) controller. Examples of the HMI controller include a controller that controls a navigation system or a display device. The global bus B2 is connected to another global bus via a not-shown central gateway (CGW).The HV ECU 50 is connected to the global bus B 2. The HV ECU 50 is configured to perform CAN communication with each controller connected to the global bus B 2. The HV ECU 50 is connected to the local bus B 1 via the gateway ECU 60. The gateway ECU 60 is configured to relay communication between the HV ECU 50 and each controller (for example, the battery ECU 13, the motor ECU 23, and the engine ECU 33) connected to the local bus B 1. The HV ECU 50 is configured to mutually perform CAN communication via the gateway ECU 60 with each controller connected to the local bus B 1. The gateway ECU 60 may be configured to collect and save data regarding the vehicle 100 (for example, various pieces of information acquired by the in-vehicle sensors, and control commands S M1, S M2, S E) described below, IWin, IWout, Win, Wout. Further, the gateway ECU 60 may have a firewall function. The gateway ECU 60 may be configured to detect unauthorized communication in cooperation with the firewall function and / or an error detection function of the CAN communication.In this embodiment, a microcomputer is used as the battery ECU 13, the motor ECU 23, the engine ECU 33, HV-ECU 50, and the gateway ECU 60. The battery ECU 13 includes a processor 13 a, a random access memory (RAM) 13 b, a storage device 13 c, and a communication interface (-I / F) 13 d. The engine ECU 23 includes a processor 23 a, a RAM 23 b, a storage device 23 c, and a communication I / F 23 d. The engine ECU 33 includes a processor 33 a, a RAM 33 b, a storage 33 c, and a communication I / F 33 d. The HV ECU 50 includes a processor 50 a, a RAM 50 b, a storage device 50 c, and a communication I / F 50 d. The gateway ECU 60 includes a processor 60 a, a RAM 60 b, a storage 60 c, and a communication I / F 60 d. For example, a central processing unit (CPU) may be used as processors. Each communication I / F includes a CAN controller. Each RAM functions as a working memory that temporarily stores data processed by the processor. Each storage device is configured to be able to save stored information. Each storage device includes, for example, a read only memory (ROM) and a rewritable nonvolatile memory. Each storage device stores, in addition to a program, information used in the program (for example, a mapping, a mathematical expression, and various parameters). Various controls of the vehicle 100 are executed when the processors execute the programs stored in the storage devices. However, the present disclosure is not limited thereto, and various controls may be executed by dedicated hardware (an electronic circuit). The number of processors included in each ECU is not limited, and any ECU may include a plurality of processors.Charge / discharge control of the battery 11 will be described with reference to FIG. 1 again. Hereinafter, the input power of the battery 11 and the output power of the battery 11 are collectively referred to as "battery power". The HV ECU 50 determines target battery power using the SOC of the battery 11. then the HV ECU 50 controls charging / discharging of the battery 11 so that the battery power comes closer to the target battery power. However, this charge / discharge control of the battery 11 is limited by an input / output restriction described below. Hereinafter, the target battery power on the charging side (input side) may be referred to as "target input power", and the target battery power on the discharging side (output side) may be referred to as "target output power". In this embodiment, the power on the discharge side is represented by a positive (+) value, and the power on the charge side is represented by a negative (-) value. However, when the magnitude of the power is compared, the absolute value is used regardless of the positive or negative sign (+ / -). That is, the magnitude of the power is smaller as the value becomes closer to zero. When an upper limit value and a lower limit value are set for the power, the upper limit value is on the side where the absolute value of the power is large, and the lower limit value is on the side where the absolute value of the power is small. The power exceeding the positive-side upper limit value means that the positive-side power becomes larger than the upper limit value (i.e., the power moves away from the positive side with respect to zero). The power exceeding the upper limit value on the negative side means that the power on the negative side becomes larger than the upper limit value (i.e., the power moves toward the negative side with respect to zero). The SOC indicates the remaining charge amount, and the ratio of the current charge amount to the fully charged charge amount is represented by a range between 0% and 100%, for example. As the measurement method of the SOC, a known method such as a current integration method or an open circuit voltage (OCV) estimation method can be adopted.FIG. 3 is a diagram showing an example of a map used for determining the target battery power. In FIG. 3, a reference value C 0 indicates a control center value of the SOC, a power value P A indicates a maximum value of the target input line, and a power value P B indicates a maximum value of the target output power. Referring to FIG. 3 together with FIG. 1, according to this map, the target battery power is "0" when the SOC of the battery 11 is the reference value C 0 and the battery 11 is neither charged nor discharged. In the range where the SOC of the battery 11 is less than the reference value C 0 (excessive discharge range), the smaller the SOC of the battery 11 is, the larger the target input power is until the target input power reaches the maximum value (power value P A). On the other hand, in a range in which the SOC of the battery 11 is greater than the reference value C 0 (overcharge range), the greater the SOC of the battery 11 until the target output reaches the maximum value (power value P B) is the target output power. The HV ECU 50 determines the target battery power according to the map shown in FIG. 3, and charges and discharges the battery 11 so that the battery power becomes closer to the determined target battery power, thereby bringing the SOC of the battery 11 closer to the reference value C 0. The reference value C 0 of the SOC may be a fixed value, or may be variable depending on the situation of the vehicle 100.The HV ECU 50 is configured to perform input restriction and output restriction of the battery 11. The HV ECU 50 sets a first power upper limit value (hereinafter referred to as "Win") indicating an input power upper limit value of the battery 11 and a second power upper limit value (hereinafter referred to as "Wout") indicating an output power upper limit value of the battery 11, and controls the battery power such that the battery power does not exceed the set values Win and Wout. The HV ECU 50 adjusts the battery power by controlling the engine 31 and the PCU 24. When Win or Wout is less (i.e., closer to zero) than the target battery power, the battery power is controlled to Win or Wout instead of the target battery power. In this embodiment, Wout corresponds to an example of the "power upper limit value" according to this disclosure.The battery ECU 13 is configured to use a detection value of the battery sensor 12 to obtain a first current upper limit value (hereinafter also referred to as "IWin") indicating an upper limit value of the input current of the battery 11. The battery ECU 13 is also configured to use a detection value of the battery sensor 12 to obtain a second current upper limit value (hereinafter also referred to as "IWout") indicating an upper limit value of the output current of the battery 11. That is, the battery pack 10 corresponds to a current limiting battery pack. On the other hand, the HV ECU 50 is configured to use Win to control the input power of the battery 11. The HV ECU 50 is configured to perform power-based input restriction (i.e., a process for controlling the input power of the battery 11 such that the input power of the battery 11 does not exceed Win). Further, the HV ECU 50 is configured to use Wout to control the output of the battery 11. The HV ECU 50 is configured to perform power-based output restriction (i.e., a process for controlling the output power of the battery 11 such that the output power of the battery 11 does not exceed Wout). That is, the HV ECU 50 corresponds to power restriction control means. In this embodiment, IWout corresponds to an example of the "current upper limit value" according to the present disclosure.As described above, the vehicle 100 includes the current limiting battery pack (i.e., the battery pack 10) and the power limiting control means (i.e., the HV ECU 50). In the vehicle 100, the current limiting battery pack and the power limiting control means are used in combination. IWin and IWout are output from the battery pack 10, and IWin and IWout are converted into Win and Wout by the gateway ECU 60 interposed between the battery pack 10 and the HV-ECU 50, respectively. With this configuration, the HV ECU 50 can suitably perform a power-based input restriction and a power-based output restriction on the battery 11 included in the battery pack 10.FIG. 4 is a diagram showing details of a configuration of the battery pack 10, the gateway ECU 60, and the HV ECU 50. S 1 and S 4 in FIG. 4 respectively indicate a first step and a fourth step, which will be described below. Referring to FIG. 4 together with FIG. 2, in this embodiment, the battery 11 included in the battery pack 10 is a assembled battery including a plurality of cells 111. Each cell 111 is, for example, a lithium ion battery. Each cell 111 includes a positive electrode terminal 111 a, a negative electrode terminal 111 b, and a battery case 111 c. The voltage between the positive electrode terminal 111 aand the negative electrode terminal 111 bcorresponds to a cell voltage Vs. In the battery 11, the positive electrode terminal 111 aof one cell 111 and the negative electrode terminal 111 bof another cell 111 adjacent to the one cell 111 are electrically connected to each other through a bus bar 112 having conductivity. The cells 111 are connected in series with each other. However, the present disclosure is not limited thereto, and any connection mode may be applied in the assembled battery.The battery pack 10 includes the battery sensor 12, the battery ECU 13, and the SMR 14 in addition to the battery 11. signals output from the battery sensor 12 to the battery ECU 13 (hereinafter also referred to as "battery sensor signals") include a voltage signal VB output from the voltage sensor 12 a, a current signal IB output from the current sensor 12 b, and a temperature signal TB output from the temperature sensor 12 c. The voltage signal VB indicates a measured value of the voltage of each cell 111 (cell voltage Vs). The current signal IB indicates a measured value of the current flowing through the battery 11 (the charging side assumes a negative value). The temperature signal TB indicates a measured value of the temperature of each cell 111.The battery ECU 13 repeatedly receives the latest battery sensor signals. The interval at which the battery ECU 13 receives the battery sensor signals (hereinafter also referred to as "sampling cycle") may be a fixed value or may be variable. In this embodiment, the sampling cycle is 8 ms. However, the present disclosure is not limited thereto, and the sampling cycle may be variable in a predetermined range (for example, a range from 1 ms to 1 s). Hereinafter, the number of times the battery ECU 13 obtains the battery sensor signals per unit time may be referred to as "sampling rate". There is a tendency that the higher the sampling rate, the greater the accuracy of obtaining Win and Wout (i.e., the conversion accuracy) via the conversion process described later.The battery ECU 13 includes an IWin calculation unit 131 and an IWout calculation unit 132. The IWin calculation unit 131 is configured to use the detection value of the battery sensor (i.e., the battery sensor signals) to obtain IWin. A known method can be used as a calculation method of IWin. The IWin calculation unit 131 may determine IWin such that charging current restriction is performed for protecting the battery 11. IWin may be determined, for example, to suppress overcharge, Li deposition, very rapid degradation, and battery overheating in the battery 11. The IWout calculation unit 132 is configured to use the detection value of the battery sensor 12 (i.e., the battery sensor signals) to obtain IWout. As the calculation method of IWout, a known method can be used. The IWout calculation unit 132 may determine IWout so that discharge current restriction is performed for protecting the battery 11. IWout may be determined, for example, to suppress overdischarge, Li deposition, very rapid deterioration, and battery overheating in the battery 11. In the battery ECU 13, the IWin calculation unit 131 and the IWout calculation unit 132 are implemented by, for example, the processor 13 ashown in FIG. 2 and the program executed by the processor 13 a. However, the present disclosure is not limited thereto, and the IWin calculation unit 131 and the IWout calculation unit 132 may be implemented by dedicated hardware (an electronic circuit).The battery pack 10 outputs the IWin calculated by the IWin calculation unit 131, the IWout calculated by the IWout calculation unit 132, and the signals (i.e., the battery sensor signals) obtained from the battery sensor 12 to the gateway ECU 60. These pieces of information are output from the battery ECU 13 included in the battery pack 10 to the gateway ECU 60 provided outside the battery pack 10. As shown in FIG. 2, the battery ECU 13 and the gateway ECU 60 exchange information through CAN communication.The gateway ECU 60 includes a conversion unit 600 described below. FIG. 5 is a diagram showing details of a configuration of the conversion unit 600. S 2 and S 3 in FIG. 5 respectively indicate a second step and a third step, which will be described later. Referring to FIG. 5 together with FIG. 4, the conversion unit 600 includes a first estimation unit 611, a second estimation unit 621, and calculation units 612 and 622. In the gateway ECU 60, for example, the conversion unit 600 (and therefore, the first estimation unit 611, the second estimation unit 621, and the calculation units 612 and 622) is implemented by the processor 60 ashown in FIG. 2 and the program executed by the processor 60 a. However, the present disclosure is not limited thereto, and the conversion unit 600 may be implemented by dedicated hardware (an electronic circuit). The conversion unit 600 according to this embodiment corresponds to an example of a "converter" according to this disclosure.The first estimation unit 611 estimates a voltage value (hereinafter referred to as "V 1") of the battery 11 in a state where a current corresponding to IWin flows. In addition, the second estimation unit 621 estimates a voltage value (hereinafter referred to as "V 2") of the battery 11 in a state where a current corresponding to IWout flows. V 2 according to this embodiment corresponds to an example of an "estimated voltage value" according to the present disclosure.FIG. 6 is a diagram for describing the method for estimating V 2 with the second estimating unit 621. Referring to FIG. 6 together with FIG. 5, the second estimation unit 621 uses the actual current and voltage of the battery 11 (i.e., the measured values of the current and voltage of the battery 11 detected by the battery sensor 12), the internal resistance of the battery 11, and IWout to obtain V 2. A graph M 1 in FIG. 6 shows the following relational expression.In the above relational expression, "R" indicates the internal resistance, "IB" indicates the actual current, and "VBs" indicates the actual voltage. In this embodiment, the average cell voltage (i.e., the average value of the voltages of all the cells 111) is applied as VBs. However, the present disclosure is not limited thereto. Instead of the average cell voltage, the maximum cell voltage (i.e., the highest voltage value among the voltages of the cells 111), the minimum cell voltage (i.e., the smallest voltage value among the voltages of the cells 111), or the inter-terminal voltage of the assembled battery (i.e., the voltage applied between the external connection terminals T 1 and T 2 when the SMR 14 is in the closed state) may be applied as VBs. The second estimation unit 621 may obtain VBs using the battery sensor signals (specifically, the voltage signal VB). The above relational expression is stored in the storage device 60 c(FIG. 2 ) in advance. The above relational expression may include a predetermined correction term (for example, a correction term regarding polarization).In this embodiment, the second estimation unit 621 refers to a map M 2 for obtaining the internal resistance of the battery 11. In the map M 2, "R" indicates the internal resistance, and "TB" indicates the temperature of the battery 11. Map M 2 illustrates information indicating the relationship between the temperature (TB) of battery 11 and the internal resistance (R) of battery 11, and is stored in storage device 60 c(FIG. 2 ) in advance. The second estimation unit 621 may obtain the internal resistance of the battery 11 from the temperature of the battery 11. The temperature of the battery 11 used for obtaining the internal resistance is, for example, a measured value of the temperature of the battery 11 detected by the temperature sensor 12 c. As the temperature of the battery 11, for example, any one of an average cell temperature, a maximum cell temperature, and a minimum cell temperature may be adopted. As shown in map M 2, the internal resistance of the battery 11 tends to decrease as the temperature of the battery 11 increases. The second estimation unit 621 may periodically acquire the actual current and the actual voltage, and correct the map M 2 based on the relationship between the actual current and the actual voltage.The method for estimating V 2 with the second estimating unit 621 has been described above with reference to FIG. 6. V1 is also estimated by a method similar to the above-described method for estimating V2. The first estimation unit 611 estimates V 1 according to the following relational expression. Since the method of estimating V 1 with the first estimating unit 611 is basically the same as the method of estimating V 2 as described above, only the relational expression is shown, and the detailed description is omitted.Referring back to FIGS. 4 and 5, the calculation unit 612 uses the V 1 obtained by the first estimation unit 611 to convert IWin into Win. Specifically, the calculation unit 612 converts IWin to Win by performing the calculation represented by the following expression F 1. The expression F 1 is stored in advance in the storage device 60 c(FIG. 2 ).The calculation unit 612 receives V 1 from the first estimation unit 611 and multiplies the IWin input from the battery pack 10 (FIG. 4 ) by V 1. In this way, the calculation unit 612 converts IWin to Win by multiplying IWin by V 1 according to the above expression F 1.The calculation unit 622 uses the V 2 obtained by the second estimation unit 621 to convert IWout into Wout. Specifically, the calculation unit 622 converts IWout to Wout by performing the calculation represented by the following expression F 2. The expression F 2 is stored in advance in the storage device 60 c(FIG. 2 ).The calculation unit 622 receives V 2 from the second estimation unit 621 and multiplies the IWout input from the battery pack 10 (FIG. 4 ) by V 2. In this way, the calculation unit 622 converts IWout to Wout by multiplying IWout by V2 according to the above expression V2.Referring to FIG. 4, IWin, IWout and the battery sensor signals from the battery pack 10 are input to the gateway ECU 60, the conversion unit 600 of the gateway ECU 60 (see FIG. 5 for the detailed configuration) converts IWin and IWout into Win and Wout, respectively. Then, Win, Wout, and the battery sensor signals are output from the gateway ECU 60 to the HV ECU 50. The gateway ECU 60 sequentially obtains IWin, IWout, and VBs from the battery pack 10 in real time, calculates Win and Wout, and sends Win and Wout to the HV ECU 50. Win and Wout sent from the gateway ECU 60 to the HV ECU 50 are sequentially updated using the latest values of IWin, IWout, and VBs (i.e., real time values). As shown in FIG. 2, the gateway ECU 60 and the HV ECU 50 exchange information through CAN communication.The HV ECU 50 includes a control unit 51 described below. In the HV ECU 50, the control unit 51 is implemented by, for example, the processor 50 ashown in FIG. 2 and the program executed by the processor 50 a. However, the present disclosure is not limited thereto, and the control unit 51 may be implemented by dedicated hardware (an electronic circuit).The control unit 51 is configured to use Win to control the input power of the battery 11. The control unit 51 is further configured to use Wout to control the output power of the battery 11. In this embodiment, the control unit 51 generates the control commands S M1, S M2 and S E respectively for the motor generators MG 21a, MG 21b shown in FIG. 1 and the engine 31 so that the input power and the output power of the battery 11 do not exceed Win and Wout, respectively. The control unit 51 outputs the control commands S M1 and S M2 for the MG 21 aand the MG 21 bto the motor ECU 23, and outputs the control command S E for the internal combustion engine 31 to the internal combustion engine ECU 33. The control commands S M1 and S M2 output from the HV ECU 50 are transmitted to the motor ECU 23 via the gateway ECU 60. The engine ECU 23 controls the PCU 24 (FIG. 1 ) according to the received control commands S M1 and S M2. The control command S E output from the HV ECU 50 is transmitted to the engine ECU 33 via the gateway ECU 60. The engine ECU 33 controls the engine 31 according to the received control command S E. The MG 21 a, the MG 21 b, and the engine 31 are controlled according to the control commands S M1, S M2 and S E so that the input power and the output power of the battery 11 are controlled not to exceed Win and Wout, respectively. The HV ECU 50 can adjust the input power and the output power of the battery 11 by controlling the internal combustion engine 31 and the PCU 24. The HV ECU 50 sequentially obtains Win and Wout from the gateway ECU 60 in real time, generates the control commands S M1, S M2 and S E using the latest values Win and Wout (i.e., the real time values), and transmits the control commands S M1, S M2 and S E to the motor ECU 23 and the engine ECU 33.As described above, the vehicle 100 according to this embodiment includes the battery pack 10 including the battery ECU 13 and the HV ECU 50 and the gateway ECU 60 provided separately from the battery pack 10. The gateway ECU 60 is configured to relay communication between the battery ECU 13 and the HV ECU 50. The conversion unit 600 is included in the gateway ECU 60. The conversion unit 600 converts IWin into Win by multiplying V 1 (i.e., the voltage value of the battery 11 in the state where the current corresponding to the IWin flows) by IWin. The conversion unit 600 converts IWout into Wout by multiplying V 2 (i.e., the voltage value of the battery 11 in the state where current corresponding to the IWout flows) by IWout. The battery ECU 13 is configured to use the detection value of the battery sensor 12 to obtain IWin (i.e., the current upper limit value indicating the upper limit value of the input current of the battery 11) and IWout (i.e., the current upper limit value indicating the upper limit value of the output current of the battery 11). The battery pack 10 is configured to output IWin and IWout. When IWin and IWout are input from the battery pack 10 to the gateway ECU 60, the conversion unit 600 of the gateway ECU 60 converts IWin and IWout into Win and Wout, respectively, and the gateway ECU 60 outputs Win and Wout to the HV ECU 50. The HV ECU 50 is configured to control the input power of the battery 11 using Win (i.e., the power upper limit value indicating the upper limit value of the input power of the battery 11). Further, the HV ECU 50 is configured to control the output power of the battery 11 using Wout (i.e., the power upper limit value indicating the output power upper limit value of the battery 11).Since the vehicle 100 includes the conversion unit 600, IWin and IWout output from the current limiting battery pack (for example, the battery pack 10) can be converted into Win and Wout, respectively. Although the voltage of the battery 11 changes depending on the magnitude of the current, the conversion unit 600 can obtain Win and Wout corresponding to IWin and IWout with high accuracy by multiplying IWin and IWout by V 1 and V 2, respectively. The HV ECU 50 can suitably perform the power-based input restriction and the power-based output restriction using the Win and Wout thus obtained.The control sections included in the vehicle 100 may be modularized in predetermined units to form a vehicle control system.FIG. 7 is a diagram showing a first example of the vehicle control system. Referring to FIG. 7, a vehicle control system 201 includes the MGs 21 aand 21 b, the motor sensors 22 aand 22 b, the motor ECU 23, the PCU 24, the engine 31, the engine sensor 32, the engine ECU 33, the single ring planetary gear 42, the HV ECU 50, and the gateway ECU 60 that are modularized. The vehicle control system 201 is configured such that the battery pack 10 (FIG. 4 ) can be mounted.FIG. 8 is a diagram showing a second example of the vehicle control system. Referring to FIG. 8, a vehicle control system 202 is configured by modularizing the control portions of the vehicle control system 201 other than the engine control portions (i.e., the engine 31, the engine sensor 32, and the engine ECU 33). The vehicle control system 202 is configured such that the battery pack 10 (FIG. 4 ) and the engine control portions can be attached.The modularized vehicle control system may be treated as a component. Modularization of the control sections as described above facilitates the manufacture of the vehicle. Modularization also allows sharing of sections between different vehicle models.The vehicle control systems 201 and 202 include the HV ECU 50 and the gateway ECU 60, respectively. When the battery pack 10 (FIG. 4 ) is added to the vehicle control systems 201 and 202, respectively, the HV ECU 50 controls the input power of the battery 11 so that the input power of the battery 11 does not exceed Win, and controls the output power of the battery 11 so that the output power of the battery 11 does not exceed Wout. In the vehicle control system 201, 202, the HV ECU 50 corresponds to an example of the "control unit" according to the present disclosure. When IWin is input from the battery pack 10, the gateway ECU 60 uses the detection value (for example, voltage, current, and temperature) of the battery sensor 12 and IWin to obtain V 1, and multiplies IWin by V 1 to convert IWin to Win. Further, when IWout is input from the battery pack 10, the gateway ECU 60 uses the detection value (for example, voltage, current, and temperature) of the battery sensor 12 and IWout to obtain V 2, and multiplies IWout by V 2 to convert IWout into Wout. In the vehicle control system 201, 202, the gateway ECU 60 corresponds to an example of the "conversion unit" according to the present disclosure.In addition, the vehicle control system 201, 202 to which the battery pack 10 is mounted may control the output power of the battery 11 by the vehicle control method including steps 1 to 4 described below.In the first step (for example, S 1 in FIG. 4 ), the vehicle control system 201, 202 obtains IWout and the detection value of the battery sensor 12 from the battery pack 10. In the third step (for example, S 3 in FIG. 5 ), the vehicle control system 201, 202 converts IWout to Wout by multiplying IWout by V 2. In the fourth step (for example, S 4 in FIG. 4 ), the vehicle control system 201, 202 controls the output power of the battery 11 using Wout.The vehicle control system 201, 202 to which the battery pack 10 is mounted may control the input power of the battery 11 by the vehicle control method including steps five to eight described below.In the fifth step, the vehicle control system 201, 202 acquires IWin and the detection value of the battery sensor 12 from the battery pack 10. In the seventh step, the vehicle control system 201, 202 converts IWin to Win by multiplying IWin by V1. In the eighth step, the vehicle control system 201, 202 controls the input power of the battery 11 using Win.According to the above vehicle control method, the vehicle control systems 201 and 202 can suitably perform the power-based input restriction and the power-based output restriction using Win and Wout.In the above-described embodiment, when the power limiting battery pack is connected to the power limiting control means, the gateway ECU 60 is applied such that the power-based input limiting and the power-based output limiting are performed on the secondary battery included in the power limiting battery pack. That is, in the above-described embodiment, the gateway ECU 60 configured to be connectable to the current limiting battery pack and that cannot be connected to the power limiting battery pack is employed. However, the present disclosure is not limited thereto, and a gateway ECU 60X shown in FIG. 9 may be applied instead of the gateway ECU 60 applied to the above-described embodiment. FIG. 9 is a diagram showing a modified example of the gateway ECU 60 shown in FIG. 4.Referring to FIG. 9, the gateway ECU 60X includes a connector C 21 for connecting a battery pack 10A to the gateway ECU 60X and a connector C 22 for connecting a battery pack 10B to the gateway ECU 60X. The battery pack 10A is a current limiting battery pack that includes an external connection connector C 11 and outputs the IWin, IWout, and the battery sensor signals to the connector C 11. The battery pack 10B is a power limiting battery pack that includes an external connection connector C 12 and outputs the Win, Wout, and the battery sensor signals to the connector C 12. The HV ECU 50 is connected to an output terminal C 3 of the gateway ECU 60X via a signal line.When the connector C 11 of the battery pack 10A is connected to the connector C 21 of the gateway ECU 60X, IWin, IWout, and the battery sensor signals from the battery pack 10A are input to the connector C 21. Then, the conversion unit 600 of the gateway ECU 60X converts IWin and IWout into Win and Wout, respectively, and Win, Wout and the battery sensor signals are output to the output terminal C 3. Then, Win, Wout, and the battery sensor signals are output from the gateway ECU 60X to the HV ECU 50.On the other hand, when the connector C 12 of the battery pack 10B is connected to the connector C 22 of the gateway ECU 60X, Win, Wout, and the battery sensor signals from the battery pack 10B are input to the connector C 22. The gateway ECU 60X outputs Win, Wout and the battery sensor signals input to the connector C 22 unchanged to the output terminal C 3. That is, the above reaction is not carried out. Thus, Win, Wout, and the battery sensor signals are output from the gateway ECU 60X to the HV ECU 50.As described above, when IWin and IWout are input, the gateway ECU 60X according to this modified example performs the conversion according to the above expressions F 1 and F 2 to output Win and Wout. When Win and Wout are input, the gateway ECU 60X outputs Win and Wout without performing the above conversion. In a vehicle including the gateway ECU 60X, Win and Wout are output from the gateway ECU 60X both in a case where the battery pack 10A is used and in a case where the battery pack 10B is used. Thus, in such a vehicle, the HV ECU 50 can suitably perform the power-based input restriction and the power-based output restriction both in a case where the battery pack 10A is applied and in a case where the battery pack 10B is applied.In the example shown in FIG. 9, the gateway ECU 60X includes the input terminal for a current limiting battery pack (connector C 21) and the input terminal for a power limiting battery pack (connector C 22) separately from each other. However, the gateway ECU may be configured to be connected to both the current limiting battery pack and the power limiting battery pack in another form. The gateway ECU may include, for example, an input terminal to which both the current limiting battery pack and the power limiting battery pack can be connected. The gateway ECU may be configured to recognize whether the battery pack is the current limiting battery pack or the power limiting battery pack in the initial process when the battery pack is connected to the input terminal. When the battery pack connected to the input terminal is the current limiting battery pack, the gateway ECU may activate conversion logic (for example, the conversion unit 600) for converting the values IWin and IWout input thereto into Win and Wout, respectively, and outputting Win and Wout to the output terminal.On the other hand, when the battery pack connected to the input terminal is the power limiting battery pack, the gateway ECU may directly output the values Win and Wout input thereto to the output terminal without activation of the conversion logic.In the above-described embodiment, the number of power upper limit values required for the output restriction of the battery 11 is one. However, the present disclosure is not limited thereto, and the output restriction may be performed using a plurality of power upper limit values. For example, an HV-ECU 50X shown in FIG. 10 may be used instead of the HV-ECU 50 used in the above embodiment. FIG. 10 is a diagram showing a modified example of the HV ECU 50 shown in FIG. 4.Referring to FIG. 10 together with FIG. 4, the hardware configuration of the HV ECU 50X is the same as the configuration of the HV ECU 50 shown in FIG. 2. however, the HV ECU 50X includes a protection unit 53 in addition to the control unit 51. However, the present disclosure is not limited thereto, and the control unit 51 and the protection unit 53 may be implemented by dedicated hardware (an electronic circuit).Win, Wout, and the battery sensor signals are input to the HV ECU 50X from the gateway ECU 60 shown in FIG. 4, for example. The protection unit 53 uses a figure. M for obtaining a third power upper limit value (hereinafter also referred to as "GWin") indicating the upper limit value of the input power of the battery 11 and a fourth power upper limit value (hereinafter also referred to as "GWout") indicating the upper limit value of the output power of the battery 11. GWin is a protection value for Win, and when Win is an abnormal value (particularly, an extremely large value), limits, instead of Win GWin, the input power of the battery 11. GWout is a protection value for Wout, and when Wout is an abnormal value (particularly, a very large value), limits GWout, instead of Wout, the output power of the battery 11.The FIGS. M represents information indicating the relationship between the temperature of the battery 11 and each of GWin and GWout, and is stored in the storage device 50 c(FIG. 2 ) in advance. A curve L 11 in the figure. M indicates the relationship between the temperature of the battery 11 and GWin. A curve L 12 in the figure. M indicates the relationship between the temperature of the battery 11 and GWout.The protection unit 53 is shown in the figure. M for obtaining GWin and GWout according to the current temperature of the battery 11. Then, the protection unit 53 outputs the smaller value of Win and GWin to the control unit 51, and outputs the smaller value of Wout and GWout to the control unit 51. For example, when the temperature of the battery 11 and Win is in a state P 11 in the figure. M, Win is output to the control unit 51, and when the temperature of the battery 11 and Win are in a state P 12 in the map, GWin (curve L 11) is output to the control unit 51. Hereinafter, the situation where Win exceeds GWin (for example, the situation where the state P 12 is established) will be referred to as "Win with protection". When the temperature of the battery 11 and Wout is in a state P 21 in the figure. M, Wout is output to the control unit 51, and when the temperature of the battery 11 and Wout is in a state P 22 in the FIG.. M, GWout (curve L 12) is output to the control unit 51. Hereinafter, the situation where Wout exceeds GWout (for example, the situation where the state P 22 is established) will be referred to as "Wout with protection".The temperature of the battery 11 used for obtaining GWin and GWout is a measured value of the temperature of the battery 11 detected by, for example, the temperature sensor 12 cshown in FIG. 4. For example, any one of the average cell temperature, the maximum cell temperature, and the minimum cell temperature may be adopted as the temperature of the battery 11.In addition to the power upper limit value, the battery sensor signals are also output from the protection unit 53 to the control unit 51. The control unit 51 controls the input power and the output power of the battery 11 using the power upper limit values received from the protection unit 53. Specifically, the control unit 51 generates the control commands S M1, S M2 for MG 21 a, Mg 21 band the control command S E for the internal combustion engine 31 shown in FIG. 1 so that the input power and the output power of the battery 11 do not exceed the upper limit power values. The control unit 51 controls the input power of the battery 11 so that the input power of the battery 11 does not exceed the smaller one of Win and GWin. As a result, the input power of the battery 11 does not exceed either Win or GWin. The control unit 51 controls the output power of the battery 11 so that the output power of the battery 11 does not exceed the smaller one of Wout and GWout. As a result, the output power of the battery 11 does not exceed either Wout or GWout.The protection unit 53 may record Win with protection and Wout with protection in the storage device 50 c(FIG. 2 ) and determine compliance / non-compliance of the vehicle-mounted battery pack (for example, the battery pack 10 shown in FIG. 4 ) based on the recorded data. For example, the protection unit 53 may determine that the battery pack is not compliant when the frequency of "Win with protection" and / or the frequency of "Wout with protection" exceeds a predetermined value. In addition, the protection unit 53 may determine that the battery pack is not compliant when the duration during which the "Win with protection" state continues and / or the duration during which the "Wout with protection" state continues exceeds a predetermined value.The HV ECU 50X may record the determination result of conformity / non-conformity of the battery pack in the storage device 50 c(FIG. 2 ). In addition, the HV ECU 50X may inform a user of the non-conformance when it is determined that the battery pack is not compliant. This notification may prompt the user to replace the battery pack. The notification process to the user is optional, and the notification may be performed by a display (for example, display of characters or images) on a display device, by sound (including voice) from a speaker, or by lighting (including blinking) a predetermined lamp.Win, Wout may exceed GWin, GWout due to insufficient accuracy of conversion of IWin, IWout to Win, Wout. Thus, when Win exceeds GWin and / or when Wout exceeds GWout, the HV ECU 50X may transmit a predetermined signal to the battery ECU 13 shown in FIG. 4 to increase the sampling rate of the battery ECU 13 (and therefore, the number of data of the battery sensor signals transmitted from the battery ECU 13 to the gateway ECU 60 per unit time).According to the modified example shown in FIG. 10, it is possible to protect the battery 11 with GWin and GWout when Win and Wout take extremely large values for some reason.In the above-described embodiment, the gateway ECU 60 includes the conversion unit 600. However, the present disclosure is not limited thereto, and another ECU may have these functions.FIG. 11 is a diagram showing a first modified example of the vehicle control system shown in FIG. 4. Referring to FIG. 11, the vehicle control system according to the first modified example is the same as the vehicle control system shown in FIG. 4 except that an HV ECU 50Y is applied instead of the HV ECU 50 and the gateway ECU 60 is omitted. The hardware configuration of the HV ECU 50Y is the same as the configuration of the HV ECU 50 shown in FIG. 2, however, the HV ECU 50Y includes the conversion unit 600 (see FIG. 5 ) in addition to the control unit 51. In the HV ECU 50Y, the control unit 51 and the conversion unit 600 are implemented by, for example, the processor 50 ashown in FIG. 2 and the program executed by the processor 50 a. However, the present invention is not limited thereto, and the control unit 51 and the conversion unit 600 may be implemented by dedicated hardware (an electronic circuit).The battery pack 10 outputs IWin, IWout, and the battery sensor signals to the HV ECU 50Y. The conversion unit 600 of the HV ECU 50Y converts the IWin and IWout output from the battery pack 10 into Win and Wout, respectively. Win and Wout are input from the conversion unit 600 to the control unit 51. The control unit 51 generates the control commands S M1, S M2 and S E for the MG 21 a, MG 21 bshown in FIG. 1, and the engine 31, respectively, and outputs the control commands S M1 and S M2 to the motor ECU 23, and outputs the control command S E to the engine ECU 33 so that the input power and the output power of the battery 11 do not exceed Win and Wout, respectively.In the vehicle control system according to the first modified example, the HV ECU 50Y provided separately from the battery pack 10 includes a converter (i.e., the conversion unit 600), and the converter converts IWin and IWout into Win and Wout. The inverter can thus be mounted on the vehicle without changing the configuration of the battery pack 10. Further, the HV ECU 50Y may suitably perform the power-based input restriction and the power-based output restriction without adding the gateway ECU 60 (FIG. 4 ) described above.FIG. 12 is a diagram showing a second modified example of the vehicle control system shown in FIG. 4. Referring to FIG. 12, the vehicle control system according to the second modified example is the same as the vehicle control system shown in FIG. 4 except that a battery pack 10X (including a battery ECU 13X) is applied instead of the battery pack 10 (including the battery ECU 13), and the gateway ECU 60 is omitted. The hardware configuration of the battery ECU 13X included in the battery pack 10X is the same as the configuration of the battery ECU 13 shown in FIG. 2. however, the battery ECU 13X includes the conversion unit 600 (see FIG. 5 ) in addition to the IWin calculation unit 131 and the IWout calculation unit 132. In the battery ECU 13X, the IWin calculation unit 131, the IWout calculation unit 132, and the conversion unit 600 are implemented by, for example, the processor 13 ashown in FIG. 2 and the program executed by the processor 13 a. However, the present disclosure is not limited thereto, and the IWin calculation unit 131, the IWout calculation unit 132, and the conversion unit 600 may be implemented by dedicated hardware (an electronic circuit).The conversion unit 600 of the battery ECU 13X receives IWin and IWout from the IWin calculation unit 131 and the IWout calculation unit 132, respectively, and converts IWin and IWout into Win and Wout. The battery pack 10X outputs Win, Wout, and the battery sensor signals to the HV ECU 50. The control unit 51 of the HV ECU 50 generates the control commands S M1, S M2 and S E for the MG 21 a, the MG 21 b, and the engine 31, respectively, shown in FIG. 1, and outputs the control commands S M1 and S M2 to the motor ECU 23, and outputs the control command S E to the engine ECU 33 so that the input power and the output power of the battery 11 do not exceed Win and Wout, respectively.In the vehicle control system according to the second modified example, the inverter (i.e., the inverter 600) is incorporated into the battery ECU 13X (i.e., inside the battery pack 10X). With this configuration, IWin and IWout inside the battery pack 10X are converted into Win and Wout, so that Win and Wout can be output from the battery pack 10X. Therefore, the HV ECU 50 can suitably perform the power-based input restriction and the power-based output restriction without adding the gateway ECU 60 (FIG. 4 ) described above.In the above-described embodiment and each modified example, the input restriction of the secondary battery is performed in conformity with the output restriction of the secondary battery, but the method of the input restriction of the secondary battery may be changed as appropriate. For example, the power upper limit value of the secondary battery on the input side may be calculated by a calculation method different from that used for the power upper limit value of the secondary battery on the output side.In the above-described embodiment and each modified example, the battery ECU 13, the motor ECU 23, and the engine ECU 33 are connected to the local bus B 1 (see FIG. 2 ). However, the present disclosure is not limited thereto, and the motor ECU 23 and the engine ECU 33 may be connected to the global bus B 2.The configuration of the vehicle is not limited to the configuration shown in FIG. 1. Although a hybrid vehicle is shown in FIG. 1, the vehicle is not limited to the hybrid vehicle, and may be, for example, an electric vehicle to which an internal combustion engine is not attached. Further, the vehicle may be a plug-in hybrid vehicle (PHV) configured such that the secondary battery in the battery pack can be charged using electric power supplied from the outside of the vehicle. Further, the HV ECU 50 may be configured to directly control the SMR 14 by bypassing the battery ECU 13. The battery 11 (secondary battery) included in the battery pack 10 is not limited to the assembled battery, and may be a single battery.

Claims

A vehicle comprising a battery pack (10) including a secondary battery, a battery sensor (12) that detects a state of the secondary battery, and a first controller, a second controller provided separately from the battery pack (10), a converter, wherein the first controller is configured to use a detection value of the battery sensor (12) to obtain a current upper limit value indicating an upper limit value of an output current of the secondary battery, the second controller is configured to use a power upper limit value indicating an upper limit value of an output power of the secondary battery to control the output power of the secondary battery, and the converter is configured to perform conversion of the current upper limit value to the power upper limit value by performing multiplication of an estimated voltage value with the current upper limit value, wherein the estimated voltage value is a voltage value of the secondary battery in a state in which a current corresponding to the current upper limit value flows, and a third controller provided separately from the battery pack (10) and configured to relay communication between the first controller and the second controller, the converter being attached to the third controller, the battery pack (10) being configured to output the current upper limit value, the vehicle is configured such that when the current upper limit value is input from the battery pack (10) to the third controller, the converter performs the conversion of the current upper limit value to the power upper limit value and the power upper limit value is output from the third controller to the second controller, and the third controller performs the conversion and output of the power upper limit value, when the current upper limit value is input, and configured to output the power upper limit value without performing the conversion when the power upper limit value is input.The vehicle according to claim 1, wherein the converter is configured to use measured values of a current and a voltage of the secondary battery detected by the battery sensor (12), an internal resistance of the secondary battery, and the current upper limit value to obtain the estimated voltage value.The vehicle according to claim 1, wherein the first controller, the second controller, and the third controller are each a microcomputer connected to a local area network in the vehicle, and in the local area network in the vehicle, the first controller is connected to the second controller via the third controller to communicate with the second controller via the third controller.A vehicle control system configured such that a battery pack including a secondary battery, a first controller, and a battery sensor that detects a state of the secondary battery is mounted on the vehicle control system, the vehicle control system comprising a second controller configured to control an output power of the secondary battery such that the output power of the secondary battery does not exceed an upper limit power value when the battery pack (10) is mounted on the vehicle control system, a conversion unit configured such that, when an upper limit current value indicating an upper limit current value of an output current of the secondary battery and a detection value of the battery sensor (12) are input from the battery pack (10), the conversion unit uses the detection value of the battery sensor (12) and the upper limit current value to obtain an estimated voltage value, wherein the estimated voltage value is a voltage value of the secondary battery in a state in which a current corresponding to the current upper limit value flows, and performs conversion of the current upper limit value to the power upper limit value by performing multiplication of the current upper limit value with the estimated voltage value, and a third controller provided separately from the battery pack (10) and configured to relay communication between the first controller and the second controller, wherein the conversion unit is mounted on the third controller, the battery pack (10) is configured to output the current upper limit value when the current upper limit value is input from the battery pack (10) to the third controller, the conversion unit is configured to perform conversion of the current upper limit value into the power upper limit value and the power upper limit value is output from the third controller to the second controller, and the third controller is configured to perform conversion and output of the power upper limit value when the current upper limit value is input and to output the power upper limit value without performing the conversion when the power upper limit value is input.A vehicle control method comprising obtaining an upper limit current value with a vehicle control system to which a battery pack (10) including a secondary battery, a first controller, and a battery sensor (12) that detects a state of the secondary battery, the upper limit current value indicating an upper limit value of an output current of the secondary battery, and a detection value of the battery sensor (12) from the battery pack (10) is attached; obtaining an estimated voltage value with the vehicle control system using the detection value of the battery sensor (12) and the upper limit current value, the estimated voltage value being a voltage value of the secondary battery in a state in which a current corresponding to the upper limit current value flows; performing conversion of the upper limit current value into an upper limit power value with a conversion unit of the vehicle control system, which indicates an upper limit value of an output power of the secondary battery by performing multiplication of the current upper limit value with the estimated voltage value, controlling the output power of the secondary battery with a second controller of the vehicle control system using the power upper limit value, and relaying communication between the first controller and the second controller with a third controller of the vehicle control system, wherein the conversion unit is mounted on the third controller, the battery pack (10) outputs the current upper limit value when the current upper limit value is input from the battery pack (10) to the third controller, the conversion unit performs the conversion of the current upper limit value to the power upper limit value and the power upper limit value is output from the third controller to the second controller, and the third controller performs the conversion and outputs the power upper limit value, when the current upper limit value is input and outputs the power upper limit value without performing the conversion when the power upper limit value is input.

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