JP2021023015A - Vehicle electrical power system - Google Patents

Abstract

To provide a vehicle electrical power system comprising a fuel battery and a secondary battery, capable of more properly suppressing exhaustion of power of the secondary battery.SOLUTION: An electrical power system 1 comprises: a drive motor 30; a fuel battery 10 for generating power supplied to the drive motor 30; a secondary battery 20 for storing power supplied to the drive motor 30; and a control unit 100 for controlling charging/discharging of the secondary battery 20. The control unit 100 executes first charging/discharging control for controlling charging/discharging of the secondary battery 20 so that a residual capacity of the secondary battery 20 approximates to a first target residual capacity, and when a prescribed condition is satisfied, executes second charging/discharging control for controlling charging/discharging of the secondary battery 20 so that the residual capacity of the secondary battery 20 approximates to a second target residual capacity higher than the first target residual capacity.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle power supply system.

In recent years, electric vehicles that travel using a drive motor as a drive source have been widely used, and some electric vehicles are equipped with a power supply system equipped with a fuel cell and a secondary battery as a power source for the drive motor. is there. In such an electric vehicle, it is important to appropriately suppress the depletion of the electric power of the secondary battery. For example, in Patent Document 1, in a vehicle power supply system including a fuel cell and a secondary battery as electric power sources, a secondary battery is obtained by effectively utilizing the time when the main switch is off for charging the secondary battery. A technique for suppressing the depletion of electric power in Japan is disclosed.

Japanese Unexamined Patent Publication No. 2001-231108

However, in a vehicle power supply system including a fuel cell and a secondary battery, it is desired to more appropriately suppress the depletion of electric power of the secondary battery. Specifically, immediately after the power supply system is restarted (that is, immediately after the vehicle restarts), there is a start-up time of the fuel cell, and in that time, the fuel cell is driven by the electric power stored in the secondary battery. It becomes necessary to drive the motor. Therefore, if high-load driving (that is, driving in which the required driving force is higher than the threshold value) is performed immediately after the power supply system is restarted, the remaining capacity of the secondary battery (hereinafter referred to as SOC) when the power supply system is restarted. (Also called System Of Charge)), the power of the secondary battery may be exhausted.

Therefore, in view of such a problem, an object of the present invention is to provide a vehicle power supply system capable of more appropriately suppressing the depletion of electric power of a secondary battery.

In order to solve the above problems, the vehicle power supply system of the present invention includes a drive motor, a fuel battery that generates power supplied to the drive motor, and a secondary battery that stores power supplied to the drive motor. A first control device comprising a battery and a control device for controlling the charge / discharge of the secondary battery, the control device controls the charge / discharge of the secondary battery so that the remaining capacity of the secondary battery approaches the first target remaining capacity. A second charge / discharge control is performed, and when a predetermined condition is satisfied, the charge / discharge of the secondary battery is controlled so that the remaining capacity of the secondary battery approaches the second target remaining capacity, which is higher than the first target remaining capacity. Execute charge / discharge control.

The second target remaining capacity outputs the required driving force to the driving motor during the start-up time of the fuel cell when high-load driving in which the required driving force is higher than the threshold value is performed within a predetermined time from the restart of the power supply system. It may be the remaining capacity corresponding to the amount of electric power required for the operation.

The control device predicts whether or not it is more likely that high-load driving in which the required driving force is higher than the threshold value will be performed within a predetermined time from the restart of the power supply system, and the high-load driving is performed as a predetermined condition. If it is predicted that it is more likely to be performed within a predetermined time from the restart of the power supply system, the second charge / discharge control may be executed.

Based on the information indicating the destination of the vehicle, the control device may predict whether or not the high-load driving is more likely to occur within a predetermined time from the restart of the power supply system.

Based on the information indicating the travel route of the vehicle, the control device may predict whether or not the high-load travel is more likely to occur within a predetermined time from the restart of the power supply system.

The control device may execute the second charge / discharge control so that the remaining capacity of the secondary battery reaches the second target remaining capacity before the vehicle arrives at the destination of the vehicle.

The control device may change the second target remaining capacity based on the parameters related to the required driving force in high load driving in which the required driving force performed within a predetermined time from the restart of the power supply system becomes higher than the threshold value. ..

According to the present invention, in a vehicle power supply system including a fuel cell and a secondary battery, it is possible to more appropriately suppress the depletion of electric power of the secondary battery.

It is a schematic diagram which shows the schematic structure of the power supply system which concerns on embodiment of this invention. It is a schematic diagram which shows typically an example of the navigation information which concerns on embodiment of this invention. It is a flowchart which shows 1st example of the process flow performed by the control apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the transition of required driving force and SOC of a secondary battery before and after the power supply system which concerns on embodiment of this invention is stopped. It is a flowchart which shows the 2nd example of the process flow performed by the control apparatus which concerns on embodiment of this invention.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, and the like shown in the embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. To do.

<Power system configuration>
The configuration of the power supply system 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic diagram showing a schematic configuration of a power supply system 1.

Specifically, the power supply system 1 is a system mounted on an electric vehicle and used to supply electric power to each device in the vehicle.

The power supply system 1 described below is merely an example of the power supply system according to the present invention, and as will be described later, the configuration of the power supply system according to the present invention is not particularly limited to the configuration of the power supply system 1.

Specifically, as shown in FIG. 1, the power supply system 1 includes a drive motor 30, a fuel cell 10 that generates electric power supplied to the drive motor 30, and electric power supplied to the drive motor 30. A secondary battery 20 for storing electricity and a control device 100 for controlling charging / discharging of the secondary battery 20 are provided. Further, the power supply system 1 includes a fuel cell converter 41, a secondary battery converter 42, an inverter 43, a navigation device 50, and a secondary battery sensor 60. In addition, in this specification, charge / discharge means at least one of charge and discharge. That is, the charge / discharge control described later includes a charge / discharge control that executes only charging.

The vehicle on which the power supply system 1 is mounted (hereinafter, also simply referred to as a vehicle) travels by using a drive motor 30 driven by using electric power supplied from at least one of the fuel cell 10 and the secondary battery 20 as a drive source. .. Specifically, the electric power generated by the fuel cell 10 is mainly used to drive the drive motor 30, and for example, the electric power generated by the fuel cell 10 is insufficient with respect to the electric power required to drive the drive motor 30. In this case, the electric power stored in the secondary battery 20 is used.

In the power supply system 1, the fuel cell 10 is connected to the inverter 43 via the fuel cell converter 41. The secondary battery 20 is connected to the inverter 43 via the secondary battery converter 42. The secondary battery 20 and the secondary battery converter 42 are connected to the inverter 43 in parallel with the fuel cell 10 and the fuel cell converter 41. The inverter 43 is connected to the drive motor 30, and the drive motor 30 is connected to the drive wheels 9.

The fuel cell 10 is a battery that generates electricity by reacting a fuel gas (specifically, hydrogen gas) and an oxidation gas (specifically, air). Specifically, the fuel cell 10 is connected to a hydrogen tank (not shown), and the hydrogen tank is filled with, for example, high-pressure hydrogen supplied to the fuel cell 10. Then, hydrogen gas is supplied from the hydrogen tank to the fuel cell 10 by a motor pump (not shown) or the like. Further, air as an oxidation gas is supplied to the fuel cell 10 by a compressor (not shown) or the like. The output of the fuel cell 10 is controlled by controlling the supply amounts of hydrogen gas and air to the fuel cell 10.

The fuel cell converter 41 is a power conversion device capable of boosting the power generated by the fuel cell 10. For example, the fuel cell converter 41 is a DCDC converter including a so-called chopper type circuit, and power conversion by the fuel cell converter 41 is controlled by controlling the operation of a switching element provided in the circuit. The electric power generated by the fuel cell 10 is supplied to the drive motor 30 via the fuel cell converter 41 and the inverter 43, and is used to drive the drive motor 30. Further, the electric power generated by the fuel cell 10 is supplied to the secondary battery 20 via the fuel cell converter 41 and the secondary battery converter 42, and can be used for charging the secondary battery 20.

The secondary battery 20 is a battery capable of charging and discharging electric power. As the secondary battery 20, for example, a lithium ion battery, a lithium ion polymer battery, a nickel hydrogen battery, a nickel cadmium battery or a lead storage battery is used, but batteries other than these may be used.

The secondary battery converter 42 is a power conversion device capable of boosting the power stored in the secondary battery 20 and further stepping down the power supplied from the fuel cell converter 41 or the inverter 43. For example, the secondary battery converter 42 is a DCDC converter including a so-called chopper type circuit, and the power conversion by the secondary battery converter 42 is controlled by controlling the operation of the switching element provided in the circuit. The electric power stored in the secondary battery 20 is supplied to the drive motor 30 via the secondary battery converter 42 and the inverter 43, and is used to drive the drive motor 30. The electric power stored in the secondary battery 20 may be supplied to an auxiliary machine in the vehicle. In that case, for example, the electric power stored in the secondary battery 20 is stored between the secondary battery 20 and the auxiliary machine. A DCDC converter capable of stepping down the power and supplying it to the auxiliary machine is provided.

The drive motor 30 can output power, and the power output from the drive motor 30 is transmitted to the drive wheels 9. As the drive motor 30, for example, a multi-phase AC type (for example, three-phase AC type) motor is used. Further, the drive motor 30 may have a function (that is, a regenerative function) as a generator that is regeneratively driven at the time of deceleration of the vehicle and generates power by using the rotational energy of the drive wheels 9.

The inverter 43 can convert the DC power supplied from the fuel cell converter 41 or the secondary battery converter 42 into AC power and supply it to the drive motor 30, and further converts the AC power generated by the drive motor 30 into DC. It is a power conversion device that can be converted into electric power and supplied to the secondary battery converter 42. The inverter 43 includes, for example, a multi-phase bridge circuit (for example, a three-phase bridge circuit), and the power conversion by the inverter 43 is controlled by controlling the operation of the switching element provided in the circuit. The electric power generated by the drive motor 30 is supplied to the secondary battery 20 via the inverter 43 and the secondary battery converter 42, and is used for charging the secondary battery 20.

The navigation device 50 is a device that guides a route from the current position of the vehicle to a destination desired by the user in response to an input operation by the user. Further, the navigation device 50 has a function of visually displaying information, and is a travel target of navigation information (for example, the current position of the vehicle and the route the vehicle is currently traveling), which is information related to route guidance. The route, the position of the destination, the distance from the current position of the vehicle to the destination on the travel route, the arrival time to the destination, etc.) are displayed.

FIG. 2 is a schematic diagram schematically showing an example of navigation information. Specifically, FIG. 2 corresponds to a display example of navigation information displayed by the navigation device 50, and FIG. 2 shows the vehicle start point P1, destination P2, current position C1 and travel route as navigation information. L1 is shown. These navigation information is output from the navigation device 50 to the control device 100, and is used for processing performed by the control device 100 as described later. The navigation device 50 can identify the current position of the vehicle by receiving radio waves from a GPS (Global Positioning System) satellite or the like.

The secondary battery sensor 60 detects various state quantities of the secondary battery 20 and outputs them to the control device 100. Specifically, the secondary battery sensor 60 detects the SOC of the secondary battery 20.

The control device 100 controls the supply of electric power in the power supply system 1.

For example, the control device 100 includes a CPU (Central Processing Unit) which is an arithmetic processing unit, a ROM (Read Only Memory) which is a storage element for storing programs and arithmetic parameters used by the CPU, and parameters which are appropriately changed in the execution of the CPU. It is composed of a RAM (Random Access Memory) or the like, which is a storage element that temporarily stores the above.

Specifically, the control device 100 controls the power supply in the power supply system 1 by controlling the operations of the fuel cell 10, the fuel cell converter 41, the secondary battery converter 42, and the inverter 43.

For example, the control device 100 can control the output of the drive motor 30 by controlling the supply of electric power from the fuel cell 10 and the secondary battery 20 to the drive motor 30.

Further, for example, the control device 100 can control the charge / discharge of the secondary battery 20 by controlling the supply of electric power from the fuel cell 10 to the secondary battery 20 and the like.

Further, the control device 100 acquires various information output from each of these devices by communicating with the navigation device 50 and the secondary battery sensor 60. The information obtained in this way is used for processing related to control of power supply in the power supply system 1.

As described above, the control device 100 communicates with each device mounted on the power supply system 1. Communication between the control device 100 and each device is realized by using, for example, CAN (Control Area Network) communication.

The function of the control device 100 according to the present embodiment may be at least partially divided by a plurality of control devices, and the plurality of functions may be realized by one control device. When the function of the control device 100 is at least partially divided by the plurality of control devices, the plurality of control devices may be connected to each other via a communication bus such as CAN.

As described above, the control device 100 controls the charging / discharging of the secondary battery 20. Specifically, the control device 100 normally controls the charging / discharging of the secondary battery 20 so that the SOC of the secondary battery 20 approaches the first target remaining capacity (hereinafter, also referred to as the first target SOC). 1 Execute charge / discharge control. The first target SOC is an SOC for continuously using the secondary battery 20 in a healthy state. It should be noted that the normal time basically means a time other than the time when a predetermined condition is satisfied and the second charge / discharge control is executed as described later.

Here, the control device 100 causes the SOC of the secondary battery 20 to approach the second target remaining capacity (hereinafter, also referred to as the second target SOC) higher than the first target remaining capacity when a predetermined condition is satisfied. The second charge / discharge control for controlling the charge / discharge of the secondary battery 20 is executed. As a result, it becomes possible to more appropriately suppress the depletion of the electric power of the secondary battery 20. As will be described later, the second target SOC is specifically the rise time of the fuel cell 10 when a high-load run in which the required driving force is higher than the threshold value is performed within a predetermined time from the restart of the power supply system 1. It is an SOC corresponding to the amount of electric power required to output the required driving force to the driving motor 30 inside. The details of the process related to the second charge / discharge control performed by the control device 100 will be described later.

<Operation of power supply system>
Subsequently, the operation of the power supply system 1 according to the embodiment of the present invention will be described with reference to FIGS. 3 to 5. In the following, as an example of the processing flow performed by the control device 100 of the power supply system 1, the first example and the second example will be described in this order.

[First example]
First, a first example of the flow of processing performed by the control device 100 will be described with reference to FIGS. 3 and 4.

FIG. 3 is a flowchart showing a first example of the flow of processing performed by the control device 100. The control flow according to the first example shown in FIG. 3 is specifically a flow of processing related to the second charge / discharge control performed by the control device 100, and is after the power supply system 1 is started (for example, the fuel cell 10). It is started after the rise time of. The control flow according to the first example shown in FIG. 3 is started in a state where the first charge / discharge control is performed.

When the control flow according to the first example shown in FIG. 3 is started, first, in step S501, the control device 100 acquires information indicating the destination of the vehicle.

For example, the control device 100 acquires information indicating the destination of the vehicle included in the navigation information output from the navigation device 50. The acquisition of information indicating the destination may be performed when a new destination is set, or may be performed regularly or irregularly while the vehicle is traveling.

Next, in step S502, the control device 100 predicts whether or not there is a higher possibility that the high-load traveling will be performed within a predetermined time from the restart of the power supply system 1 when the vehicle stops at the destination. .. In the following, the possibility that the high load running is performed within a predetermined time from the restart of the power supply system 1 is also referred to as the high load running possibility. When it is predicted that the high load running possibility when the vehicle stops at the destination is higher than the standard (step S502 / YES), the process proceeds to step S503. On the other hand, when it is predicted that the high load traveling possibility when the vehicle is stopped at the destination is below the standard (step S502 / NO), the process returns to step S501, and the processes of step S501 and step S502 are repeated.

In addition, high load running means running in which the required driving force (that is, the driving force required for running the vehicle) is higher than the threshold value. The threshold value is set to a value higher than the average value of the required driving force during normal load driving or low load driving of the vehicle. The threshold value may be appropriately different depending on the specifications of the vehicle and the like. Further, the above-mentioned predetermined time means a time from the time when the power supply system 1 is restarted to at least the time from the time when the start-up of the fuel cell 10 is completed.

Here, the control device 100 performs the prediction process of step S502 based on the information indicating the destination of the vehicle.

For example, the control device 100 predicts that when the destination of the vehicle is a point on a mountain road, the possibility of high-load traveling when the vehicle stops at the destination is higher than the standard.

Note that the control device 100 may predict that the possibility of high-load traveling when the vehicle stops at the destination is higher than the standard because the destination of the vehicle is a point other than the point on the mountain road. ..

For example, the control device 100 states that the possibility of high-load traveling when the vehicle stops at the destination is higher than the standard because the destination of the vehicle is a point on the highway (for example, an interchange or a service area). You may predict. Further, for example, the control device 100 determines that the vehicle can travel at a high load when the vehicle stops at the destination because the destination of the vehicle is a point on a mountain road or a point near a point on an expressway. You may expect it to be high.

The reference value in the prediction process in step S502 may be, for example, a reference value such as 50%, or may be something other than a numerical value. The criteria are from the viewpoint of improving the certainty that the depletion of electric power of the secondary battery 20 is suppressed at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1 and the frequency with which the second charge / discharge control is unnecessarily executed. Can be appropriately set from the viewpoint of reducing the amount of fuel. Specifically, the lower the standard is set, the greater the effect of improving the certainty that the depletion of the power of the secondary battery 20 at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1 is suppressed. Therefore, the frequency with which the second charge / discharge control is unnecessarily executed also increases. Further, the higher the criterion in the above determination is set, the less the effect of improving the certainty that the depletion of the electric power of the secondary battery 20 is suppressed at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1 is reduced. The frequency with which the second charge / discharge control is unnecessarily executed is also reduced.

If YES is determined in step S502, in step S503, the control device 100 determines whether or not the arrival time to the destination is less than the reference time. If it is determined that the arrival time to the destination is less than the reference time (step S503 / YES), the process proceeds to step S504. On the other hand, when it is determined that the arrival time to the destination has not reached the reference time (step S503 / NO), the process of step S503 is repeated.

For example, the control device 100 can perform the prediction process of step S503 based on the information including the navigation information indicating the arrival time from the current position of the vehicle to the destination.

Here, the reference time is set to a sufficient time as the time required for the SOC of the secondary battery 20 to reach the second target SOC from the time when the second charge / discharge control is started. For example, the reference time starts the second charge / discharge control when the SOC of the secondary battery 20 is the lowest SOC that can be taken during the execution of the first charge / discharge control at the time when the second charge / discharge control is started. The time required for the SOC of the secondary battery 20 to reach the second target SOC is set to be longer than the estimated time from that point.

If YES is determined in step S503, in step S504, the control device 100 starts the second charge / discharge control.

As described above, in the second charge / discharge control, the charge / discharge of the secondary battery 20 is controlled so that the SOC of the secondary battery 20 approaches the second target SOC higher than the first target SOC. As a result, by executing the second charge / discharge control, the SOC of the secondary battery 20 is the second target SOC which is higher than the first target SOC which is the target value of the SOC in the first charge / discharge control. It can be increased to a value near.

By the way, as described above, immediately after the power supply system 1 is restarted (that is, immediately after the vehicle is restarted), there is a start-up time of the fuel cell 10, so that the secondary battery 20 is charged with electricity at that time. It becomes necessary to drive the drive motor 30 using electric power. Therefore, if high-load driving is performed within a predetermined time from the restart of the power supply system 1, the SOC of the secondary battery 20 when the power supply system 1 is restarted is only about the first target SOC. There is a risk that the power of the next battery 20 will be exhausted. Therefore, even if the high load running is performed within a predetermined time from the restart of the power supply system 1, the SOC of the secondary battery 20 is set near the second target SOC by the time the power supply system 1 is restarted. By raising the value to the value, it is possible to prevent the power of the secondary battery 20 from being exhausted during the start-up time of the fuel cell 10.

Here, from the viewpoint of appropriately suppressing the depletion of the electric power of the secondary battery 20 at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1, the second target SOC is that the high load running causes the restart of the power supply system 1. It is preferable that the SOC corresponds to the amount of electric power required to output the required driving force to the driving motor 30 during the start-up time of the fuel cell 10 when the operation is performed within a predetermined time.

Further, from the viewpoint of more appropriately suppressing the depletion of the electric power of the secondary battery 20 at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1, the control device 100 is within a predetermined time from the restart of the power supply system 1. It is preferable to change the second target SOC based on the parameters related to the required driving force in the high load running performed. Specifically, it is preferable that the control device 100 increases the second target SOC as the required driving force predicted based on the parameters increases.

For example, the control device 100, as the above parameters, is based on various information about the road in or near the destination of the vehicle (for example, gradient, speed limit, coefficient of friction, degree of undulation, information about traffic light or traffic jam information, etc.). The second target SOC may be changed. Further, for example, the control device 100 has the second target SOC based on the parameter indicating the tendency of the accelerator operation amount of the driver (for example, the parameter indicating whether or not the driver tends to depress the accelerator strongly) as the above parameter. May be changed.

As described above, in the control flow shown in FIG. 3, the second charge / discharge control is started when the arrival time to the destination falls below the reference time. Therefore, the control device 100 can execute the second charge / discharge control so that the SOC of the secondary battery 20 reaches the second target SOC before the vehicle arrives at the destination of the vehicle. As a result, the SOC of the secondary battery 20 can be appropriately reached to the second target SOC by the time when the vehicle arrives at the destination of the vehicle and a request to stop the power supply system 1 is generated by the operation of the driver. Therefore, the second charge / discharge control is continuously executed after the time when the stop request of the power supply system 1 is generated by the operation of the driver (that is, the secondary battery 20 is charged using the generated power of the fuel cell 10). It can be suppressed.

Next, the control flow shown in FIG. 3 ends.

In the first example, the second charge / discharge control ends, for example, when the power supply system 1 is stopped. Further, after the power supply system 1 is restarted, for example, the charge / discharge control of the secondary battery 20 using the target SOC is not performed during the rise time of the fuel cell 10, and the first charge / discharge control starts after the lapse of the time. Will be done.

Here, with reference to FIG. 4, an example of the transition of various state quantities when the control flow shown in FIG. 3 is executed will be described.

FIG. 4 is a diagram showing an example of the transition of the required driving force and the SOC of the secondary battery 20 before and after the power supply system 1 is stopped.

In the example shown in FIG. 4, it is predicted that the possibility of high-load driving when the vehicle stops at the destination is higher than the reference time before the time T1, and the arrival time to the destination at the time T1 is the reference time. Corresponds to the example when it is determined that the value is less than.

Since the vehicle is running with the first charge / discharge control executed until the time T1, the SOC of the secondary battery 20 is set to a value near the first target SOC as shown in FIG. It is maintained. Then, at time T1, the SOC of the secondary battery 20 begins to rise as the second charge / discharge control is started, and at time T2 after time T1, the SOC of the secondary battery 20 becomes the second target. Reach the SOC. After that, at time T3, the vehicle arrives at the destination and stops, and the power supply system 1 is stopped by the operation of the driver. Therefore, as shown in FIG. 4, at time T3, the required driving force becomes 0 [N] as the vehicle stops.

Then, at time T4 after the time T3, the power supply system 1 is restarted as the vehicle restarts. Here, in the example shown in FIG. 4, immediately after the time T4 when the power supply system 1 is restarted, the required driving force is a value F ₀ so that the traveling state corresponds to a high load traveling. By the way, the SOC of the secondary battery 20 has risen to a value near the second target SOC at time T4 by executing the second charge / discharge control. Therefore, at the rise time of the fuel cell 10 immediately after the time T4 when the power supply system 1 is restarted, the drive motor 30 is driven by the electric power stored in the secondary battery 20. It is possible to prevent the power of the next battery 20 from being exhausted.

As described above, in the first example described with reference to FIG. 3, the control device 100 is subjected to high-load traveling within a predetermined time from the restart of the power supply system 1 based on the information indicating the destination of the vehicle. Predict whether the possibility of being done (that is, the possibility of high-load driving) is higher than the standard. Then, the control device 100 executes the second charge / discharge control when it is predicted that the high load traveling is more likely to be performed within the predetermined time from the restart of the power supply system 1 as a predetermined condition. As a result, when the vehicle stops at the destination and there is a high possibility that the high load traveling will be performed within a predetermined time from the restart of the power supply system 1, the second charge / discharge control can be executed. Therefore, even if the high-load running is performed within a predetermined time from the restart of the power supply system 1 after the vehicle has stopped at the destination, the secondary battery 20 has to be restarted before the power supply system 1 is restarted. Since the SOC can be raised to a value near the second target SOC, it is possible to prevent the power of the secondary battery 20 from being exhausted during the start-up time of the fuel battery 10.

[Second example]
Next, a second example of the flow of processing performed by the control device 100 will be described with reference to FIG.

The second example described with reference to FIG. 5 uses information indicating the traveling route of the vehicle in the prediction processing of whether or not the high load traveling possibility is higher than the reference as compared with the first example described above. The point is different.

FIG. 5 is a flowchart showing a second example of the flow of processing performed by the control device 100. The control flow according to the second example shown in FIG. 5 is a flow of processing related to the second charge / discharge control performed by the control device 100, similarly to the control flow according to the first example described above. Yes, it is started after the power supply system 1 is started (for example, after the start-up time of the fuel cell 10 has elapsed). The control flow according to the second example shown in FIG. 5 is started in a state where the first charge / discharge control is performed, similarly to the control flow according to the first example described above.

When the control flow according to the second example shown in FIG. 5 is started, first, in step S601, the control device 100 acquires information indicating the traveling route of the vehicle.

For example, the control device 100 acquires information indicating the traveling route of the vehicle included in the navigation information output from the navigation device 50.

Next, in step S602, the control device 100 may be subjected to high-load traveling within a predetermined time from the restart of the power supply system 1 when the vehicle is stopped on the traveling route (that is, high-load traveling possibility). Predict whether is higher than the standard. When it is predicted that the possibility of high-load driving when the vehicle is stopped on the traveling route is higher than the standard (step S602 / YES), the process proceeds to step S603. On the other hand, when it is predicted that the high load traveling possibility when the vehicle is stopped on the traveling route is equal to or less than the standard (step S602 / NO), the process returns to step S601 and the processes of steps S601 and S602 are repeated.

Here, the control device 100 performs the prediction process of step S602 based on the information indicating the traveling route of the vehicle.

For example, the control device 100 predicts that the possibility of high-load traveling is higher than the standard when the vehicle stops on the traveling route because the traveling route of the vehicle is a mountain road.

The control device 100 may predict that the possibility of high-load traveling is higher than the standard when the vehicle stops on the traveling route because the traveling route of the vehicle is a route other than the mountain road.

For example, the control device 100 may predict that the high load traveling possibility is higher than the standard when the vehicle stops on the traveling route because the traveling route of the vehicle is an expressway.

Further, when the type of road is different between the current position in the traveling route of the vehicle and the position ahead of the current position, the control device 100 determines the type of road at the position ahead of the current position in the traveling route. Based on this, the prediction process of step S602 may be performed. For example, even if the type of road at the current position on the travel route is a general road, the vehicle stops on the travel route because the type of road at a position ahead of the current position on the travel route is an expressway. It may be predicted that the possibility of high-load driving is higher than the standard.

The reference in the prediction process of step S602 is the same as the prediction process of step S502 in the control flow according to the first example described above, that is, the secondary battery 20 at the rise time of the fuel cell 10 immediately after the restart of the power supply system 1. It can be appropriately set from the viewpoint of improving the certainty that the depletion of electric power is suppressed and the viewpoint of reducing the frequency of unnecessary execution of the second charge / discharge control.

If YES is determined in step S602, the control device 100 starts the second charge / discharge control in step S603.

Next, the control flow shown in FIG. 5 ends.

In the second example, as in the first example, the second charge / discharge control ends, for example, when the power supply system 1 is stopped, and after the power supply system 1 is restarted, for example, the fuel. The first charge / discharge control is started after the rise time of the battery 10 has elapsed.

As described above, in the second example described with reference to FIG. 5, the control device 100 performs high-load traveling within a predetermined time from the restart of the power supply system 1 based on the information indicating the traveling route of the vehicle. Predict whether the possibility of being done (that is, the possibility of high-load driving) is higher than the standard. Then, the control device 100 executes the second charge / discharge control when it is predicted that the high load traveling is more likely to be performed within the predetermined time from the restart of the power supply system 1 as a predetermined condition. As a result, when the vehicle stops on a travel route such as a mountain road or an expressway where heavy load travel is expected, there is a possibility that high load travel will be performed within a predetermined time from the restart of the power supply system 1. When it is high, the second charge / discharge control can be executed. Therefore, even if the power supply system 1 is restarted after the vehicle has stopped on the travel route and the high load travel is performed within a predetermined time, the secondary battery 20 is restarted before the power supply system 1 is restarted. Since the SOC of the above can be raised to a value near the second target SOC, it is possible to prevent the power of the secondary battery 20 from being exhausted at the start-up time of the fuel battery 10.

In the above, with reference to each control flow shown in FIGS. 3 and 5, the first example and the second example have been described as examples of the flow of processing performed by the control device 100, but the processing performed by the control device 100 has been described. Is not particularly limited to these examples.

For example, in the first example, the second charge / discharge control is started when the arrival time to the destination is less than the reference time, and in the second example, it is predicted that the high load running possibility is higher than the reference time. The second charge / discharge control is started at a time point, but the start timing of the second charge / discharge control is not limited to these examples. For example, the second charge / discharge control may be started when the vehicle stops after the high load traveling possibility is predicted to be higher than the reference. In this case, after the time when the stop request of the power supply system 1 is generated by the operation of the driver, the second charge / discharge control is continuously executed until the SOC of the secondary battery 20 reaches the second target SOC. (That is, the secondary battery 20 may be charged using the generated power of the fuel cell 10).

Further, for example, in the first example and the second example, it is predicted whether or not the high load running possibility is higher than the standard, and when the high load running possibility is predicted to be higher than the standard, the second charge / discharge is performed. Although the control has been executed, the second charge / discharge control may be executed without such a prediction. For example, the control device 100 may execute the second charge / discharge control when the vehicle is stopped as a predetermined condition without predicting whether or not the high load traveling possibility is higher than the reference.

<Effect of power supply system>
Subsequently, the effect of the power supply system 1 according to the embodiment of the present invention will be described.

In the power supply system 1 according to the present embodiment, the control device 100 executes the first charge / discharge control for controlling the charge / discharge of the secondary battery 20 so that the SOC of the secondary battery 20 approaches the first target SOC. When the above condition is satisfied, the second charge / discharge control for controlling the charge / discharge of the secondary battery 20 is executed so that the SOC of the secondary battery 20 approaches the second target SOC higher than the first target SOC. Therefore, by executing the second charge / discharge control, the SOC of the secondary battery 20 is set to the second target SOC which is higher than the first target SOC which is the target value of the SOC in the first charge / discharge control. It can be increased to a nearby value. As a result, even if high-load driving is performed within a predetermined time after the power supply system 1 is restarted, the SOC of the secondary battery 20 is set near the second target SOC by the time the power supply system 1 is restarted. By raising the value to the value of, it is possible to prevent the power of the secondary battery 20 from being exhausted during the start-up time of the fuel cell 10. Therefore, in the power supply system 1 of the vehicle including the fuel cell 10 and the secondary battery 20, the depletion of the electric power of the secondary battery 20 can be suppressed more appropriately.

Further, according to the power supply system 1 according to the present embodiment, the power consumption of the secondary battery 20 is exhausted at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1 without increasing the capacity of the secondary battery 20. Since it can be suppressed, it is possible to suppress an increase in the weight of the power supply system 1, an increase in cost, and a deterioration in electricity cost.

Further, according to the power supply system 1 according to the present embodiment, the rise time of the fuel cell 10 immediately after the restart of the power supply system 1 without increasing the first target SOC, which is the target value of the SOC in the first charge / discharge control. It is possible to suppress the exhaustion of the electric power of the secondary battery 20 in the above. Here, for example, when the target value of the SOC in the first charge / discharge control is made higher than the conventional one without executing the second charge / discharge control, the SOC of the secondary battery 20 is basically always higher than the conventional one. Therefore, there is a risk that it may be difficult to properly operate the regenerative function of the drive motor 30, or the deterioration of the secondary battery 20 may be accelerated. Therefore, in the power supply system 1 according to the present embodiment, it is possible to suppress the depletion of the electric power of the secondary battery 20 at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1 while avoiding such a problem. ..

Further, in the power supply system 1 according to the present embodiment, the second target SOC is the drive motor 30 during the start-up time of the fuel cell 10 when the high-load running is performed within a predetermined time from the restart of the power supply system 1. It is preferable that the SOC corresponds to the amount of electric power required to output the required driving force. As a result, it is appropriately suppressed that the power of the secondary battery 20 is exhausted due to the drive motor 30 being driven by the power stored in the secondary battery 20 at the start-up time of the fuel cell 10. can do.

Further, in the power supply system 1 according to the present embodiment, the control device 100 predicts whether or not it is more likely than the reference that the high load running is performed within a predetermined time from the restart of the power supply system 1 as a predetermined condition. However, when it is predicted that the high load running is more likely to be performed within a predetermined time from the restart of the power supply system 1, it is preferable to execute the second charge / discharge control. As a result, when the possibility that the high-load running will be performed within a predetermined time from the restart of the power supply system 1 is higher than the standard, the second charge / discharge control can be appropriately executed, so that the power supply system 1 is restarted. It is possible to appropriately suppress the depletion of the electric power of the secondary battery 20 at the start-up time of the fuel cell 10 immediately after.

Further, in the power supply system 1 according to the present embodiment, the control device 100 is based on the possibility that the high-load traveling is performed within a predetermined time from the restart of the power supply system 1 based on the information indicating the destination of the vehicle. It is preferable to predict whether it is high or not. As a result, the second charge / discharge control can be executed when there is a high possibility that the high load traveling will be performed within a predetermined time from the restart of the power supply system 1 when the vehicle stops at the destination. Therefore, even if the high-load running is performed within a predetermined time from the restart of the power supply system 1 after the vehicle has stopped at the destination, the secondary battery 20 has to be restarted before the power supply system 1 is restarted. Since the SOC can be raised to a value near the second target SOC, it is possible to prevent the power of the secondary battery 20 from being exhausted during the start-up time of the fuel battery 10.

Further, in the power supply system 1 according to the present embodiment, the control device 100 is based on the possibility that the high-load running is performed within a predetermined time from the restart of the power supply system 1 based on the information indicating the traveling route of the vehicle. It is preferable to predict whether it is high or not. As a result, the second charge / discharge control can be executed when there is a high possibility that the high load traveling will be performed within a predetermined time from the restart of the power supply system 1 when the vehicle is stopped on the traveling route. .. Therefore, even if the power supply system 1 is restarted after the vehicle has stopped on the travel route and the high load travel is performed within a predetermined time, the secondary battery 20 is restarted before the power supply system 1 is restarted. Since the SOC of the above can be raised to a value near the second target SOC, it is possible to prevent the power of the secondary battery 20 from being exhausted at the start-up time of the fuel battery 10.

Further, in the power supply system 1 according to the present embodiment, the control device 100 performs a second charge / discharge so that the SOC of the secondary battery 20 reaches the second target SOC before the vehicle arrives at the destination of the vehicle. It is preferable to carry out control. As a result, the SOC of the secondary battery 20 can be appropriately reached to the second target SOC by the time when the vehicle arrives at the destination of the vehicle and a request to stop the power supply system 1 is generated by the operation of the driver. Therefore, the second charge / discharge control is continuously executed after the time when the stop request of the power supply system 1 is generated by the operation of the driver (that is, the secondary battery 20 is charged using the generated power of the fuel cell 10). It can be suppressed.

Further, in the power supply system 1 according to the present embodiment, the control device 100 sets the second target SOC based on the parameters related to the required driving force in the high load running performed within a predetermined time from the restart of the power supply system 1. It is preferable to change it. As a result, when high-load driving is performed within a predetermined time from the restart of the power supply system 1, the amount of electric power required to output the required driving force to the driving motor 30 during the rising time of the fuel cell 10 is increased. The second target SOC can be changed appropriately. Therefore, it is more appropriately suppressed that the power of the secondary battery 20 is exhausted due to the drive motor 30 being driven by the power stored in the secondary battery 20 at the start-up time of the fuel cell 10. can do. Therefore, it is possible to more appropriately suppress the depletion of the electric power of the secondary battery 20 at the start-up time of the fuel cell 10 immediately after the restart of the power supply system 1.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and various modifications within the scope of claims are described. It goes without saying that the modified examples also belong to the technical scope of the present invention.

For example, in the above, the configuration of the power supply system 1 has been described with reference to FIG. 1, but the configuration of the power supply system according to the present invention is not limited to such an example, and for example, the power supply system shown in FIG. A part of the components may be deleted, added or changed with respect to 1. For example, the power supply system according to the present invention also includes a power supply system 1 shown in FIG. 1 in which the secondary battery converter 42 is deleted.

Further, for example, the processes described by using the flowchart in the present specification do not necessarily have to be executed in the order shown in the flowchart. Further, additional processing steps may be adopted, and some processing steps may be omitted.

The present invention can be used in power supply systems.

1 Power supply system 9 Drive wheels 10 Fuel cell 20 Secondary battery 30 Drive motor 41 Fuel cell converter 42 Secondary battery converter 43 Inverter 50 Navigation device 60 Secondary battery sensor 100 Control device

Claims (7)

Drive motor and
A fuel cell that generates electric power supplied to the drive motor,
A secondary battery that stores the electric power supplied to the drive motor,
A control device that controls the charging and discharging of the secondary battery,
With
The control device is
The first charge / discharge control for controlling the charge / discharge of the secondary battery is executed so that the remaining capacity of the secondary battery approaches the first target remaining capacity.
When a predetermined condition is satisfied, the second charge / discharge control for controlling the charge / discharge of the secondary battery so that the remaining capacity of the secondary battery approaches the second target remaining capacity higher than the first target remaining capacity is performed. Execute,
Vehicle power system. The second target remaining capacity is set in the driving motor during the start-up time of the fuel cell when a high-load running in which the required driving force is higher than the threshold value is performed within a predetermined time from the restart of the power supply system. The remaining capacity corresponding to the amount of power required to output the required driving force,
The vehicle power supply system according to claim 1. The control device predicts whether or not it is more likely than the reference that high-load driving in which the required driving force is higher than the threshold value is performed within a predetermined time from the restart of the power supply system.
As the predetermined condition, when it is predicted that the high load running is more likely to be performed within the predetermined time from the restart of the power supply system than the reference, the second charge / discharge control is executed.
The vehicle power supply system according to claim 1 or 2. Based on the information indicating the destination of the vehicle, the control device predicts whether or not the high load traveling is more likely to be performed within the predetermined time from the restart of the power supply system than the reference.
The vehicle power supply system according to claim 3. Based on the information indicating the traveling route of the vehicle, the control device predicts whether or not the high load traveling is more likely to be performed within the predetermined time from the restart of the power supply system than the reference.
The vehicle power supply system according to claim 3 or 4. The control device executes the second charge / discharge control so that the remaining capacity of the secondary battery reaches the second target remaining capacity before the vehicle arrives at the destination of the vehicle.
The vehicle power supply system according to any one of claims 1 to 5. The control device changes the second target remaining capacity based on the parameters related to the required driving force in high load driving in which the required driving force performed within a predetermined time from the restart of the power supply system becomes higher than the threshold value. Let,
The vehicle power supply system according to any one of claims 1 to 6.

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