Method for controlling electric vehicle, and electric vehicle system

Abstract

Provided is a method for controlling an electric vehicle comprising a battery to be charged by a charger provided at a charging spot. This control method involves setting a target battery temperature at which to start charging at a destination charging spot that has been set as a charging spot where the battery is to be charged, and estimating a speed profile of the electric vehicle up to the time of starting charging on the basis of road information and / or past travel information about the route leading to the destination charging spot. The control method further involves controlling the timing at which to implement temperature control on the basis of a weather profile of the route leading to the destination charging spot and the estimated speed profile, such that the battery temperature reaches the target battery temperature at the time of starting charging and such that the energy loss, which is the sum of the energy consumption associated with the travel of the electric vehicle and the energy consumption associated with the control of the temperature of the battery, is minimized.

Description

Electric vehicle control method and electric vehicle system

[0001] The present invention relates to a control method for an electric vehicle and an electric vehicle system.

[0002] JP 4228086B1 discloses an electric vehicle equipped with a battery that can be charged externally. When the electric vehicle arrives at a destination where charging is possible, the temperature of the battery is controlled so that the temperature is at a temperature that provides good charging efficiency (optimum charging temperature), thereby improving charging efficiency during charging after arriving at the destination.

[0003] In the electric vehicle described in JP4228086B1, the battery temperature reaches an optimum charging temperature when the vehicle arrives at a destination where charging is possible, but if the battery is warmed up to the optimum charging temperature and then maintained at that temperature until the vehicle arrives at the destination, there is a risk that energy consumption will increase in order to maintain the optimum charging temperature. In other words, in some cases, energy consumption will increase and electricity efficiency will deteriorate.

[0004] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a control method and an electric vehicle system for an electric vehicle that reduce energy consumption while maintaining a battery temperature at a temperature that provides good charging efficiency when charging begins.

[0005] According to one aspect of the present invention, there is provided a method for controlling an electric vehicle having a battery that is charged by a charger provided at a charge spot. The method sets a target battery temperature when charging starts at a destination charge spot that is set as a charge spot for charging the battery, and estimates a speed profile of the electric vehicle up to the start of charging based on at least one of road information and past driving information for the route to the destination charge spot. Then, based on a weather profile for the route to the destination charge spot and the estimated speed profile, controls the timing of temperature control so that the battery temperature reaches the target battery temperature at the start of charging and minimizes energy loss, which is the sum of energy consumption due to vehicle travel and energy consumption due to battery temperature control.

[0006] FIG. 1 is a schematic configuration diagram of an electric vehicle system according to one embodiment. FIG. 2 is a diagram showing a calculation flow for estimating a charge waiting time. FIG. 3 is a diagram showing a calculation flow for calculating a temperature control implementation section and the magnitude of a temperature control output. FIG. 4 is a block diagram of a portion related to battery temperature and energy management control. FIG. 5 is a flowchart explaining battery temperature and energy management control. FIG. 6 is a diagram explaining the effect of a control method for an electric vehicle according to this embodiment. FIG. 7 is a diagram explaining the effect of a control method for an electric vehicle according to this embodiment.

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0008] 1 is a schematic diagram of an electric vehicle system 100 according to one embodiment. The electric vehicle system 100 is an electric vehicle system mounted on an electric vehicle to which a control method according to one embodiment of the present invention is applied. The electric vehicle here is, for example, a hybrid vehicle, an electric vehicle, or the like.

[0009] As shown in FIG. 1, the electric vehicle system 100 includes a battery temperature control system 1, a battery pack 2, a charging port 3, a navigation system 4, and a controller 5 mounted on an electric vehicle (hereinafter simply referred to as a "vehicle"), a cloud 6 outside the vehicle, and a user terminal 7 such as a smartphone that is a portable information terminal.

[0010] The battery temperature control system 1 controls the temperature of the battery in the battery pack 2. The battery temperature control system 1 and the battery pack 2 are provided on a cooling water passage 10, and the battery temperature control system 1 causes a heat medium (coolant) in the cooling water passage 10 to receive or release heat, and circulates and supplies the heat medium to the battery in the battery pack 2. The heat medium that has received or released heat is supplied to the battery, thereby heating or cooling the battery. The battery temperature control system 1 includes, for example, an HVAC device 11, a PTC heater 12, a radiator 13, a motor unit 14, and a circuit switching mechanism 15.

[0011] The HVAC system (hereinafter simply referred to as "HVAC") 11 is an air conditioning system that controls the temperature, humidity, and air quality in the passenger compartment of an electric vehicle. The HVAC 11 forms an AC cycle with a chiller, compressor, condenser, expander, etc., and supplies temperature-regulated air to the passenger compartment. The HVAC 11 is controlled by a controller 5.

[0012] The PTC heater 12 is an electric heating device that operates using stored power from a battery and uses a PTC element whose resistance increases as the temperature rises. The PTC heater 12 heats the heat medium in the cooling water passage 10. The PTC heater 12 is controlled by the controller 5.

[0013] The radiator 13 exchanges heat between the heat medium in the cooling water passage 10 and the air outside the vehicle compartment, and cools the heat medium by dissipating heat from the heat medium to the outside of the vehicle compartment.

[0014] The motor unit 14 is mainly composed of a motor that functions as a drive source for the electric vehicle, and an inverter that adjusts the power supplied to the motor. The motor and inverter of the motor unit 14 are heated or cooled by heat exchange with the heat medium in the cooling water passage 10. The operation of the inverter of the motor unit 14 is controlled by the controller 5.

[0015] The circuit switching mechanism 15 includes a switching valve, a water pump, etc., and switches the circuit (flow of cooling water) in the cooling water passage 10 in the battery temperature adjustment system 1. The operation of the circuit switching mechanism 15 is controlled by the controller 5.

[0016] The battery temperature control system 1 configured as described above functions as a warming circuit that heats the battery of the battery pack 2 or as a cooling circuit that cools the battery. Whether the battery temperature control system 1 configures a warming circuit or a cooling circuit depends on how the HVAC 11, the PTC heater 12, and the circuit switching mechanism 15 are controlled.

[0017] The configuration of the battery temperature adjustment system 1 is not limited to the above, and any known configuration may be used as long as it is capable of heating and cooling the battery 2.

[0018] The battery pack 2 is, for example, a lithium-ion battery, and includes a plurality of battery modules 21. The battery module 21 is configured by connecting a plurality of battery cells in series or by connecting them in a combination of series and parallel, and the battery pack 2 is provided with a plurality of battery modules 21. The plurality of battery modules 21 are connected in parallel to each other to form a high-output, large-capacity battery. The battery may also be configured by connecting a plurality of battery modules 21 in series. The battery configured by the plurality of battery modules 21 supplies power to the motor unit 14 for driving the motor.

[0019] The battery pack 2 is mounted on a cooling plate having a cooling water passage 10 therein, and the battery (hereinafter also referred to as "battery 2") of the battery pack 2 is heated or cooled by the heat medium in the cooling water passage being heated or cooled by the battery temperature control system 1. A battery current I ＢＴ a current sensor for detecting the battery voltage V ＢＴ a voltage sensor to detect the battery temperature T ＢＴ The detected values ​​of these sensors are sent to the controller 5.

[0020] The charging port 3 constitutes a connection port for a charging connector from external charging equipment. The charging port 3 is electrically connected to each battery module 21 of the battery 2. When the charging connector of a charger is connected to the charging port 3, power is supplied from the charger to charge the battery 2. When the charging connector of the charger is connected to the charging port 3, connection information of the charger is transmitted to the controller 5.

[0021] The navigation system 4 is a system that provides guidance to a user of an electric vehicle (hereinafter referred to as the “vehicle user”) on routes to a destination, etc., and stores or acquires various information to be provided to the vehicle user. The navigation system 4 is configured to be able to communicate with a cloud 6 and a user terminal 7 (described later) and acquires road information, weather information, destination information, past driving information to the destination, etc., from the cloud 6 or from the cloud 6 via the user terminal 7. The road information includes traffic congestion information, speed limit information, road gradient information, etc., and the weather information includes information on the weather (sunny, rainy, snowy, cloudy, etc.) and outside temperature, etc. The navigation system 4 also acquires map information from a database (not shown) and vehicle position information from a GPS receiver (not shown), for example. The navigation system 4 has an operation unit (not shown) that allows the vehicle user to set a destination, etc., and a display unit (not shown) that displays the set destination, the current location of the electric vehicle, maps of the surrounding areas, the driving route to the destination, traffic congestion information, etc. Therefore, information is provided to the vehicle user mainly by displaying it on the display unit, but is not limited to this and may be provided by voice, etc. The destination can be set by the vehicle user through an input operation to the navigation system 4, but may also be set via the user terminal 7.

[0022] Furthermore, when a charging spot (destination charging spot) where the battery 2 is to be charged is set as a destination, the navigation system 4 acquires from the cloud 6 a weather profile, which is a history of weather information up to the destination charging spot, and a road gradient profile up to the destination charging spot. The navigation system 4 also estimates (calculates) a speed profile up to the destination charging spot and a charging wait time from arrival at the destination charging spot until charging starts. In this case, the navigation system 4 estimates the speed profile up to the destination charging spot based on road information up to the destination charging spot, including congestion information, speed limit information, road gradient information, etc., and past driving information on the route to the destination charging spot. The navigation system 4 also estimates the charging wait time based on usage information on a charger provided at the destination charging spot (hereinafter referred to as "charger usage information"). In this embodiment, the speed profile up to the destination charging spot is a speed profile of the time and speed from the present time until arrival at the destination charging spot. Note that the speed profile does not need to be estimated using all of the above information; it can be estimated using at least either road information up to the destination charging spot or past driving information on the route to the destination charging spot. Specifically, the charging wait time is estimated according to the flow shown in Figure 2. First, current charger usage information and information on past usage records (learned data, etc.) for the time and day of week up to the time of expected arrival at the destination charging spot are acquired from the cloud 6 and / or the user terminal 7. Then, based on this information, the congestion level at the charging spot at the time of expected arrival of the electric vehicle at the destination charging spot is predicted, and the charging wait time is estimated. Next, the navigation system 4 estimates a speed profile up to the start of charging by adding the speed during the charging wait time (set to 0) to the speed profile up to the destination charging spot. The weather profile, road gradient profile, and the estimated speed profile and charging wait time up to the start of charging acquired by the navigation system 4 are transmitted to the controller 5.

[0023] The controller 5 is composed of one or more computers (microcomputers) equipped with a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and an input / output interface (I / O interface). The controller 5 performs control by having the CPU execute a program stored in the ROM or RAM. The program may be stored in a non-transitory storage medium such as a CD-ROM.

[0024] The controller 5 receives input of detected values ​​from various sensors, a speed profile and destination information (charger usage information) from the navigation system 4. The controller 5 is also communicably connected to the cloud 6 and a user terminal 7, and receives input of information such as road information, weather information, destination information, and past driving information to the destination from the cloud 6 and / or the user terminal 7. In this embodiment, when a charging spot for charging the battery 2 is set as the destination, the controller 5 executes battery temperature and energy management control based on the input detected values ​​and various information to control the temperature of the battery 2 to reach an optimum charging temperature and to suppress energy consumption at the start of charging. The battery temperature and energy management control will be described in detail later.

[0025] The controller 5 also includes an in-vehicle controller unit (in-vehicle C / U) 51, a charge controller 52, an EV controller 53, and a battery controller 54.

[0026] The on-board controller unit (on-board C / U) 51 comprehensively controls various systems and devices of the electric vehicle. The on-board C / U 51 also manages the battery temperature and energy consumption. The on-board C / U 51 receives vehicle position information, road information, weather information, etc. from the navigation system 4, and receives the SOC of the battery 2, the temperature of the battery 2 (battery temperature) T from a battery controller 54 (described later). ＢＴThe vehicle C / U 51 receives the following information: vehicle location information from the navigation system 4; a road gradient profile from the current location to the destination charging spot; a weather profile; an estimated speed profile from the present to the start of charging; and an estimated charging wait time. The vehicle C / U 51 sets a temperature (optimum charging temperature) that provides optimal charging efficiency as the target battery temperature at the start of charging. Based on the various input information, the vehicle C / U 51 calculates a section (hereinafter referred to as the "temperature control section") in which temperature control of the battery 2 is performed so that the temperature of the battery 2 reaches the target battery temperature and energy consumption is suppressed at the start of charging of the battery 2; and a temperature control output profile, which is a history of the amount of power output from the battery 2 to the HVAC 11 and the PTC heater 12 from the present to the start of charging. In this embodiment, the temperature control section is calculated as a time range, i.e., the start and end times of temperature control.

[0027] The temperature control section and the temperature control output profile are calculated in detail according to the calculation flow shown in FIG. 3 . As shown in FIG. 3 , the onboard C / U 51 calculates the running resistance and grade resistance of the electric vehicle from the present to the start of charging based on the speed profile and the road gradient profile. Then, the onboard C / U 51 calculates the driving force of the electric vehicle from the present to the start of charging based on the calculated running resistance and grade resistance. The onboard C / U 51 also estimates the power consumption of the air conditioner (A / C) from the present to the start of charging based on the weather profile. The onboard C / U 51 also calculates the amount of heat dissipated by the battery 2 into the outside air from the present to the start of charging (hereinafter referred to as "battery outside air heat dissipation amount") based on the weather profile and a temperature profile, which is a history of the temperature of the battery 2 from the present to the start of charging. The weather profile used to calculate the outside air heat dissipation amount is, in detail, a profile of the outside air temperature from the present to the start of charging. The calculation of the temperature profile will be described later. Next, the on-board C / U 51 calculates a profile of power consumption due to driving and air conditioning up to the start of charging based on the speed profile, the driving force up to the start of charging, and the air conditioning power consumption up to the start of charging. The on-board C / U 51 also calculates the SOC of the battery 2 from the present to the start of charging based on the profile of power consumption due to driving and air conditioning. The on-board C / U 51 then calculates the internal resistance of the battery 2 from the present to the start of charging based on the SOC and temperature profile up to the start of charging. The on-board C / U 51 then calculates the loss of the battery 2 from the present to the start of charging based on the internal resistance of the battery 2 up to the start of charging and the power consumption due to driving and air conditioning up to the start of charging. The amount of heat generated by the battery 2 from the present to the start of charging (hereinafter referred to as "battery heat generation amount") is then calculated based on the battery loss up to the start of charging. The on-board C / U 51 calculates the energy loss, which is the sum of the energy consumption due to the running of the electric vehicle and the energy consumption due to the temperature control of the battery 2, based on the temperature control output profile, which is a history of the temperature control output value from the present to the start of charging, the temperature control implementation section, the amount of heat dissipated into the air outside the battery, and the amount of heat generated by the battery. Also, the on-board C / U 51 calculates the temperature profile based on the temperature control output profile, the temperature control implementation section, the amount of heat dissipated into the air outside the battery, and the amount of heat generated by the battery.

[0028] Here, the temperature profile, the temperature control output profile, and the temperature control execution section are calculated and determined as follows: First, the in-vehicle C / U 51 calculates the temperature T ＢＴ A temperature control output profile and a temperature control implementation section are provisionally determined so that the battery 2 reaches the target battery temperature. A temperature profile is then calculated based on the provisionally determined temperature control output profile and temperature control implementation section. Once the temperature profile is calculated, the amount of heat generated by the battery and the amount of heat dissipated into the air outside the battery are calculated. Then, the temperature profile, energy loss, temperature control output profile, and temperature control implementation section are repeatedly calculated using an optimization algorithm that sets the condition that the temperature of the battery 2 reaches the target battery temperature at the start of charging and has the objective function of minimizing energy loss. In this way, a temperature control output profile and a temperature control implementation section are calculated so that the temperature of the battery 2 reaches the target battery temperature at the start of charging and energy loss is minimized.

[0029] The temperature control implementation section and the temperature control output profile calculated by the on-board C / U 51 are transmitted to the EV controller 53 as instruction signals.

[0030] The charge controller 52 receives charger connection information from the charge port 3 and controls the charge voltage, charge time, etc. during charging based on the SOC of the battery 2 estimated by a battery controller 54 (described later).

[0031] The EV controller 53 controls the operation of the inverter of the motor unit 14 to control the power supply from the battery 2 to the motor unit 14. The EV controller 53 also controls the battery temperature control system 1 (HVAC 11, PTC heater 12, and circuit switching mechanism 15) based on instruction signals for the temperature control implementation section and temperature control output profile input from the on-board C / U 51, to warm (heat) or cool the battery 2.

[0032] The battery controller 54 detects the battery current I from a current sensor, a voltage sensor, and a temperature sensor provided for the battery 2. ＢＴ , battery voltage V ＢＴ , battery temperature TＢＴ The battery controller 54 also acquires the detected value of the battery voltage V ＢＴ and battery temperature T ＢＴ The SOC of the battery 2 is estimated from the battery temperature T ＢＴ The detected value is transmitted to the in-vehicle C / U 51 and the EV controller 53 , and the estimated SOC of the battery 2 is transmitted to the in-vehicle C / U 51 and the charge controller 52 .

[0033] The cloud 6 is a server external to the electric vehicle that has a database of traffic information, weather information, and the like. The electric vehicle system 100 can access the cloud 6 from the navigation system 4, the controller 5, or via a user terminal 7. The electric vehicle system 100 can obtain various types of information from the cloud 6, such as road information, weather information, destination information, and past driving information. The vehicle user can also obtain various types of information by accessing the cloud 6 via the user terminal 7.

[0034] The user terminal 7 is a mobile information terminal such as a smartphone. The vehicle user can set a destination using the user terminal 7. For example, the vehicle user sets the nearest charging spot (destination charging spot) as the destination. As described above, the destination setting can also be input directly into the navigation system 4.

[0035] As described above, the temperature control output profile and temperature control implementation section are calculated so that the temperature of battery 2 reaches the target battery temperature at the start of charging and energy loss is minimized, and temperature control is performed based on this, thereby improving power consumption.

[0036] As described above, in this embodiment, the temperature control output profile and the temperature control execution section are determined based on not only the speed profile but also the battery temperature T ＢＴ The calculation is based on the amount of heat generated by the battery (self-heating) based on the internal resistance of the battery 2, which is correlated with the battery temperature TＢＴ By keeping the battery 2 at a high temperature, the energy consumption of the battery 2 during driving can be reduced, resulting in suppressed energy loss. Therefore, power consumption can be further improved. In addition, since the temperature control is based on the amount of heat generated by the battery (self-heating) based on the internal resistance of the battery 2 and the amount of heat dissipated by the battery into the outside air, if there is a large difference between the target battery temperature and the outside air temperature, or if snow or rain on the road is blown up onto the underside of the battery 2 and there is a large amount of heat dissipated by the battery 2 into the outside air, the temperature control output is increased and temperature control is performed just before the start of charging, even if the temperature control efficiency is poor. Therefore, heat loss to the outside can be suppressed, and as a result, energy loss can be suppressed, resulting in further improved power consumption.

[0037] Furthermore, as described above, in this embodiment, the temperature control output profile and the temperature control implementation section are calculated based on the charger usage information as well, that is, the temperature control output profile and the temperature control implementation section are calculated taking into account the charging wait time, so that it is possible to prevent the temperature of battery 2 from dropping during the charging wait time, thereby preventing large energy losses.

[0038] Note that, because a large temperature difference within the battery 2 can cause deterioration and output reduction of the battery 2, it is preferable to set the temperature control output profile taking into account temperature deviations within the battery 2. Therefore, for example, the temperature control output profile may be set within a range in which the temperature difference between the coolant temperature in the cooling water passage 10 at the inlet of the battery 2 and the coolant temperature in the cooling water passage 10 at the outlet does not exceed a predetermined value (threshold value). In this case, when calculating the temperature profile, energy loss, temperature control output profile, and temperature control implementation section, the calculations are performed also under the condition that the temperature difference between the inlet temperature and the outlet temperature of the battery 2 does not exceed the threshold value. Note that this threshold value can be determined in advance through experiments or the like from the perspective of protecting the battery 2. In this way, by controlling the magnitude of the temperature control output within a range in which the temperature difference within the battery 2 does not exceed the threshold value, deterioration and output reduction of the battery 2 can be suppressed, thereby further protecting the battery 2.

[0039] Furthermore, the calculation flow for calculating the temperature control implementation section and the temperature control output profile described above is an example, and the temperature control implementation section and the temperature control output profile do not necessarily need to be calculated in accordance with this flow. In other words, the temperature control implementation section and the temperature control output profile may be calculated using any known calculation method as long as the calculation is based on at least the speed profile and the weather profile.

[0040] FIG. 4 is a block diagram of a portion of the electric vehicle system 100 that is related to battery temperature and energy management control.

[0041] As shown in FIG. 4, the battery temperature and energy management control is mainly executed by a calculation unit B1, an instruction unit B2, and a temperature information acquisition unit B3.

[0042] The calculation unit B1 calculates the temperature control implementation section and the temperature control output profile. The calculation unit B1 is composed of the navigation system 4, the on-board C / U 51, the cloud 6, and the user terminal 7. The calculation unit B1 acquires information about the destination charging spot, which is the destination set by the vehicle user, and estimates the speed profile up to the start of charging based on road information (including traffic congestion information, speed limit information, and road gradient profile) of the route to the destination charging spot, past driving information of the route to the destination charging spot, charger usage information, etc. The calculation unit B1 also sets a target battery temperature at the start of charging, and calculates the battery temperature T ＢＴ The temperature profile, energy loss, temperature control execution section, and temperature control output profile are calculated so that the target battery temperature is reached and the energy loss is minimized. The calculated temperature profile, temperature control execution section, and temperature control output profile are sent to the instruction section B2 as instruction signals.

[0043] The calculation unit B1 also receives the battery temperature T ＢＴ The battery temperature T ＢＴIf the temperature profile does not follow the calculated temperature profile, the temperature profile, the energy loss, the temperature control section, and the temperature control output profile are recalculated. The recalculated temperature profile, the temperature control section, and the temperature control output profile are sent to the instruction unit B2 as an instruction signal.

[0044] The instruction unit B2 controls the temperature control timing and temperature control output based on instruction signals of the temperature control section and the temperature control output profile, thereby controlling the temperature of the battery 2. In this embodiment, the instruction unit B2 is configured by the EV controller 53. The instruction unit B2 controls the HVAC 11, PTC heater 12, radiator 13, motor unit 14, and circuit switching mechanism 15 as heat sources, to warm or cool the battery 2.

[0045] The instruction unit B2 also receives the battery temperature T ＢＴ The battery temperature T ＢＴ It is determined whether the battery temperature T ＢＴ If the temperature profile does not follow the temperature profile, the instruction unit B2 stops temperature control of the battery 2 until it receives an instruction signal for the recalculated temperature profile, temperature control execution section, and temperature control output profile.

[0046] The temperature information acquisition unit B3 acquires the temperature of the battery 2 as needed. In this embodiment, the temperature information acquisition unit B3 is configured by the battery controller 54. The temperature information acquisition unit B3 acquires the acquired battery temperature T ＢＴ is transmitted to the calculation unit B1 and the instruction unit B2.

[0047] As described above, the electric vehicle system 100 performs temperature control of the battery 2 based on the temperature profile, temperature control implementation section, and temperature control output profile calculated by the calculation unit B1.

[0048] However, if the battery temperature is controlled solely with the consideration of achieving the optimum charging temperature upon arrival at a chargeable destination, energy loss may increase, resulting in poor fuel economy. For example, if the battery is warmed up to the optimum charging temperature and then maintained at that temperature until arrival at the destination, energy consumption may increase in order to maintain the optimum charging temperature. Furthermore, if the battery is preheated to a temperature higher than the optimum charging temperature in anticipation of a drop in battery temperature by the time the vehicle arrives at the destination, excessive energy loss may occur.

[0049] In contrast to this, in this embodiment, the speed profile up to the start of charging is estimated based on road information on the route to the destination charging spot, past driving information on the route to the destination charging spot, charger usage information, etc. Then, the battery temperature T ＢＴ The temperature control section and the temperature control output are controlled so that the battery temperature T reaches the target battery temperature, which is the optimum temperature for charging, at the start of charging, and the energy loss, which is the sum of the energy consumption due to the running of the electric vehicle and the energy consumption due to the temperature control of the battery 2, is minimized. ＢＴ can be controlled to a temperature that provides good charging efficiency.

[0050] 5 is a flowchart illustrating the battery temperature and energy management control. The following controls are all executed by the navigation system 4 and / or the controller 5. The navigation system 4 and the controller 5 acquire various pieces of information from the cloud 6 and the user terminal 7 as needed. The controller 5 also acquires detection values ​​from various sensors as needed.

[0051] When the vehicle user sets a charging spot as a destination in the navigation system 4 or the user terminal 7, the battery temperature and energy management control is started.

[0052] In step S101, the controller 5 sets a temperature at which charging efficiency is good (optimum charging temperature) as the target battery temperature at the start of charging. The target battery temperature is set to a temperature at which charging efficiency is best, taking into consideration, for example, the charge acceptance by the charger at the charging spot (charger specifications, etc.) and protection of the battery 2.

[0053] In step S102, the navigation system 4 estimates (calculates) a speed profile up to the start of charging based on road information to the destination charging spot, past driving information on the route to the destination charging spot, charger usage information, etc.

[0054] In step S103, the controller 5 calculates a profile of power consumption due to driving and air conditioning up to the start of charging, based on the speed profile and the weather profile (outside temperature profile).

[0055] In step S104, the controller 5 determines the battery temperature T ＢＴ The temperature profile, energy loss, temperature control execution section, and temperature control output profile are calculated so that the battery temperature reaches the target battery temperature and the energy loss is minimized. Specifically, as described above, the calculations are performed using an optimization algorithm that uses the temperature of battery 2 reaching the target battery temperature at the start of charging as a condition based on the amount of heat generated by the battery and the amount of heat dissipated into the air outside the battery, and that has the objective function of minimizing the energy loss.

[0056] Ideally, the temperature control section and the temperature control output profile are calculated so that energy loss is minimized, but they do not necessarily have to be calculated to achieve a complete minimum. For example, the temperature control section and the temperature control output profile may be calculated so that energy loss falls within a predetermined percentage. In other words, "minimizing energy loss" here includes not only the case where energy loss is completely minimized, but also the case where loss is suppressed to a predetermined range.

[0057] After calculating the temperature profile, energy loss, temperature control section, and temperature control output profile, in step S105, the controller 5 determines whether the electric vehicle has reached the temperature control section. Whether the electric vehicle has reached the temperature control section is determined, for example, using a timer or clock built into the controller 5, based on whether the temperature control start time has arrived. The processing of step S105 is repeated until the electric vehicle reaches the temperature control section.

[0058] When the temperature control execution section is reached, in step S106, the controller 5 starts temperature control of the battery 2 with an output in accordance with the temperature control output profile.

[0059] When the temperature control of the battery 2 is started, in step S107, the controller 5 ＢＴ Determine whether the battery temperature T follows the temperature profile. ＢＴ If the battery temperature T does not follow the temperature profile, the controller 5 temporarily stops the temperature adjustment and returns to the processing of steps S102 to S104. ＢＴ The controller 5 recalculates the temperature profile, energy loss, temperature control implementation section, and temperature control output profile so that the target battery temperature is reached and the energy loss is minimized. After recalculating the temperature profile, energy loss, temperature control implementation section, and temperature control output profile, the controller 5 executes the processing from step S105 onwards.

[0060] In step S107, the battery temperature T ＢＴ If the temperature profile is being followed, in step S108, the controller 5 determines whether the temperature control implementation section has ended. Whether the temperature control implementation section has ended is determined, for example, using a timer or clock built into the controller 5, based on whether the temperature control end time has arrived. If the temperature control implementation section has not ended, the controller 5 returns to the processing of step S107. Note that the end of the temperature control implementation section also occurs when the charging connector of the charger is connected to the charging port 3.

[0061] If the temperature control implementation section has ended, in step S109, the controller 5 ends the temperature control of the battery 2 and ends the battery temperature and energy management control.

[0062] In this embodiment, the temperature control implementation section and the temperature control output profile are calculated, but it is also possible to keep the temperature control output value in the temperature control implementation section constant and calculate only the time at which temperature control of battery 2 starts (hereinafter referred to as the ``temperature control start timing'') and the magnitude of the temperature control output at the temperature control start timing.

[0063] Furthermore, as in the present embodiment, it is preferable to calculate the temperature control output profile and the temperature control implementation section based not only on the speed profile but also on the amount of heat generated by the battery (self-heating) and the amount of heat dissipated into the air from the battery, but this is not necessarily limited to this. That is, the temperature control output profile and the temperature control implementation section may be calculated without considering either or both of the amount of heat generated by the battery (self-heating) and the amount of heat dissipated into the air from the battery.

[0064] Furthermore, as in the present embodiment, it is preferable to calculate the temperature control implementation section and the temperature control output profile based on charger usage information as well, but this is not necessarily limited to this. That is, the temperature control implementation section and the temperature control output profile may be calculated without taking into account charger usage information (i.e., charger waiting time). In this case, the arrival time at the charging spot is considered to be the charging start time.

[0065] Furthermore, in this embodiment, each profile is calculated and / or acquired as a profile corresponding to time (hours of the day). However, when calculating the temperature control section and the temperature control output profile without taking into account the charger usage information, the profile may be calculated and / or acquired as a profile corresponding to a position. For example, the speed profile may be calculated as a profile of the speed at each position on the route to the destination charging spot. In this case, whether the temperature control section has been reached and whether the temperature control section has ended can be determined based on the position information of the electric vehicle, etc.

[0066] Furthermore, in this embodiment, the estimation of the speed profile and the like is performed by the navigation system 4, but this is not limiting and these may also be performed by the controller 5. Furthermore, in this embodiment, some of the processes performed by the controller 5 may also be performed by the navigation system 4. That is, in this embodiment, the processes performed by the controller 5 and the processes performed by the navigation system 4 may be performed by either the controller 5 or the navigation system 4.

[0067] 6 and 7 are diagrams illustrating the effects of the control method for an electric vehicle according to this embodiment.

[0068] FIG. 6 shows the battery temperature T ＢＴ 6 shows the temperature profile of the battery at the start of charging and the energy loss (energy consumption due to driving and temperature control). ＢＴ After temperature control, the battery temperature T ＢＴ On the other hand, in this embodiment, the battery temperature T ＢＴ In order to ensure that the battery reaches the optimum charging temperature, the start timing of temperature control is delayed compared to Comparative Examples 1 to 3. Note that t0, t1, and t2 in Fig. 6 are the start timings of temperature control in Comparative Examples 1, 2, and 3, respectively, and t3 is the start timing of temperature control in this embodiment. Also, t4 is the start timing of charging.

[0069] As shown in FIG. 6, in Comparative Examples 1 to 3, the battery temperature T ＢＴ If the battery temperature T reaches the optimum charging temperature before charging starts, ＢＴ In contrast, in this embodiment, the battery temperature T ＢＴ The timing for starting temperature control is delayed compared to the comparative example so that the battery reaches the optimum charging temperature, thereby suppressing energy loss.

[0070] FIG. 7 is a diagram showing a case where the temperature control output value is constant and the amount of heat generated by the battery (self-heating) and the amount of heat dissipated by the battery to the outside air are taken into consideration. Comparative Examples 4 to 6 in FIG. 7 are examples where the amount of heat generated by the battery (self-heating) and the amount of heat dissipated by the battery to the outside air are not taken into consideration. Note that t5, t6, and t7 in FIG. 7 are the timings at which temperature control is started in Comparative Examples 4, 5, and 6, respectively, and t8 is the timing at which temperature control is started in this embodiment. Also, t9 is the timing at which charging starts.

[0071] As shown in FIG. 7, in Comparative Examples 4 to 6, the battery temperature T ＢＴ However, because the amount of heat generated by the battery (self-heating) and the amount of heat dissipated by the battery into the air outside are not taken into consideration, the battery loss (energy consumption due to driving) and heat loss to the outside during driving are greater than in this embodiment, and the total energy loss is greater than in this embodiment. In contrast, in this embodiment, the amount of heat generated by the battery (self-heating) and the amount of heat dissipated by the battery into the air outside are taken into consideration, so the battery loss and heat loss to the outside during driving can be reduced, and the total energy loss is reduced compared to Comparative Examples 4 to 6.

[0072] According to the control method for an electric vehicle of the above embodiment, the following effects can be obtained.

[0073] According to the control method for an electric vehicle of this embodiment, the speed profile of the electric vehicle up to the start of charging is estimated based on at least one of road information on the route to the destination charging spot and past driving information on the route to the destination charging spot. Then, the battery temperature T ＢＴ The timing to start temperature control is controlled so that the battery temperature T reaches the target battery temperature, which is the optimum temperature for charging, at the start of charging, and the energy loss, which is the sum of the energy consumption due to the running of the electric vehicle and the energy consumption due to the temperature control of the battery 2, is minimized. ＢＴ can be controlled to a temperature that provides good charging efficiency.

[0074] According to the control method for an electric vehicle of this embodiment, the battery temperature T ＢＴ The timing of temperature control is controlled so that the target battery temperature is reached at the start of charging and energy loss of the electric vehicle is minimized. In this way, the timing of temperature control is controlled based on the charger usage information as well. That is, since the timing of temperature control is controlled taking into consideration the charging wait time, it is possible to prevent the temperature of the battery 2 from decreasing during the charging wait time, thereby preventing energy loss from increasing.

[0075] According to the control method for an electric vehicle of this embodiment, the battery temperature T ＢＴ The timing of temperature control and the magnitude of the temperature control output are controlled so that the battery reaches the target battery temperature at the start of charging and energy loss in the electric vehicle is minimized. In other words, since not only the timing of temperature control but also the magnitude of the temperature control output are controlled, even if the temperature control efficiency is poor, in cases where increasing the temperature control output would reduce energy loss in the electric vehicle, the temperature control output can be increased to reduce energy loss. Therefore, electricity efficiency can be further improved.

[0076] According to the control method for an electric vehicle of this embodiment, the battery temperature T ＢＴ The timing of temperature control and the magnitude of the temperature control output are controlled so that the target battery temperature is reached at the start of charging and the energy loss, which is the sum of the energy consumption due to the running of the electric vehicle and the energy consumption due to the temperature control of battery 2, is minimized. In this way, the timing of temperature control and the magnitude of the temperature control output are controlled based on the charger usage information as well. In other words, since the timing of temperature control and the magnitude of the temperature control output are controlled taking into account the charging wait time, it is possible to prevent the temperature of battery 2 from decreasing during charging wait time, thereby preventing an increase in energy loss.

[0077] According to the control method for an electric vehicle of this embodiment, the energy consumption due to the running of the electric vehicle is calculated based on weather information for the route to the destination charging spot, a speed profile, and the internal resistance of the battery 2, which is correlated with the temperature of the battery 2. In other words, the timing for implementing temperature control and the magnitude of the temperature control output are controlled taking into consideration that the increase in the temperature of the battery 2 due to the amount of heat generated by the battery (self-heating) based on the internal resistance of the battery 2 reduces the energy consumption due to running. As a result, even if the energy consumption due to temperature control increases, the temperature control output can be increased to reduce the battery temperature T ＢＴ By keeping the temperature at a high level, the energy consumption of the battery 2 during driving can be reduced, and as a result, energy loss can be suppressed. Therefore, the electric efficiency can be further improved.

[0078] According to the control method for an electric vehicle of this embodiment, the energy consumption due to temperature control of the battery 2 is calculated based on weather information for the route to the destination charging spot, the speed profile, and the amount of heat generated by the internal resistance of the battery 2. That is, when the difference between the target battery temperature and the outside air temperature is large, the timing of temperature control and the magnitude of the temperature control output are controlled taking into consideration the need to increase the temperature control output to suppress heat loss to the outside. Therefore, when the amount of heat dissipated by the battery 2 to the outside air is large, even if the temperature control efficiency is poor, the temperature control output can be increased, and temperature control can be performed just before charging begins, thereby suppressing heat loss to the outside. This further improves power efficiency.

[0079] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

Claims

1. A control method for an electric vehicle having a battery that is charged by a charger provided at a charging spot, comprising the steps of: setting a target battery temperature at the start of charging at a destination charging spot that is set as the charging spot for charging the battery; estimating a speed profile of the electric vehicle up to the start of charging based on at least one of road information on the route to the destination charging spot and past driving information; and controlling the timing to start the temperature control based on the weather profile on the route to the destination charging spot and the estimated speed profile so that the battery temperature reaches the target battery temperature at the start of charging and so that energy loss, which is the sum of energy consumption due to driving of the electric vehicle and energy consumption due to temperature control of the battery, is minimized.

2. A control method for an electric vehicle as described in claim 1, comprising controlling the timing of performing the temperature control based on a weather profile for the route to the destination charging spot, the estimated speed profile, and usage information for a charger installed at the destination charging spot, so that the battery temperature reaches the target battery temperature at the start of charging and energy loss, which is the sum of energy consumption due to driving of the electric vehicle and energy consumption due to temperature control of the battery, is minimized.

3. A control method for an electric vehicle as described in claim 1, comprising controlling the timing of performing the temperature control and the magnitude of the output of the temperature control based on a weather profile for the route to the destination charging spot and the estimated speed profile so that the battery temperature reaches the target battery temperature at the start of charging and so that energy loss, which is the sum of energy consumption due to driving of the electric vehicle and energy consumption due to temperature control of the battery, is minimized.

4. A control method for an electric vehicle as described in claim 3, comprising controlling the timing of performing the temperature control and the magnitude of the output of the temperature control based on a weather profile for the route to the destination charging spot, the estimated speed profile, and usage information for a charger installed at the destination charging spot, so that the battery temperature reaches the target battery temperature at the start of charging and energy loss, which is the sum of energy consumption due to driving of the electric vehicle and energy consumption due to temperature control of the battery, is minimized.

5. A control method for an electric vehicle according to claim 3 or 4, wherein energy consumption by the driving of the electric vehicle is calculated based on weather information for the route to the destination charging spot, the estimated speed profile, and the internal resistance of the battery, which is correlated with the temperature of the battery.

6. A control method for an electric vehicle according to claim 3 or 4, wherein the energy consumption due to temperature control of the battery is calculated based on weather information for the route to the destination charging spot, the estimated speed profile, and the amount of heat generated by the internal resistance of the battery.

7. A method for controlling an electric vehicle according to claim 3 or 4, wherein the magnitude of the temperature control output is controlled within a range in which the temperature difference within the battery does not exceed a predetermined value.

8. An electric vehicle system having a battery that is charged by a charger provided at a charging spot, comprising a controller that controls temperature control of the battery, wherein the controller: sets a target battery temperature when charging starts at a destination charging spot that is set as the charging spot where the battery will be charged; estimates a speed profile of the electric vehicle up to the time charging starts based on at least one of road information on the route to the destination charging spot and past driving information; and controls the timing to start the temperature control based on a weather profile on the route to the destination charging spot and the estimated speed profile so that the battery temperature reaches the target battery temperature at the time charging starts and energy loss, which is the sum of energy consumption due to driving of the electric vehicle and energy consumption due to temperature control of the battery, is minimized.

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