JP7313273B2 - electric vehicle - Google Patents

Description

The present invention relates to an electric vehicle having a first power supply and a second power supply.

Generally, an electric vehicle having a traction motor or a hybrid vehicle having a traction motor and an engine includes a high-voltage battery that supplies power to the electric motor, and a lead battery that supplies power to electrical devices (including auxiliary devices) other than the electric motor. Additionally, such vehicles are equipped with a DC/DC converter that powers electrical equipment other than the electric motor from the high voltage battery.

Patent Literature 1 discloses a technique of switching a switch to supply electric power to a plurality of loads in a vehicle having a DC/DC converter, a battery, and a plurality of loads when idling is stopped or when the engine is restarted.

JP 2015-217919 A

Vehicles are equipped with high-load equipment that temporarily consumes a large amount of power to generate power, such as an engine restart motor and an actuator that realizes emergency automatic braking with a driving support device. When a high-load device is driven, the power supply voltage drops abruptly, which may affect other electrical devices connected to the same power source.

On the other hand, in a vehicle with multiple power sources such as a lead battery and a DC/DC converter, one power source drives a high-load device while the other power source supplies power to other electrical devices, thereby avoiding the voltage drop caused by the high-load device affecting other electrical devices. However, if a situation arises in which many other electrical devices are connected to another power supply when a high-load device is driven, a high-capacity power source is required, such as by increasing the output capacity of the other power source, assuming that these electrical devices consume power at the same time. And the cost of the power supply rises accordingly.

An object of the present invention is to provide an electric vehicle having a first power source, a second power source, and a first device that temporarily generates power, in which the required performance of the first power source and the second power source can be reduced while reducing the influence of driving the first device on other electric devices.

The invention according to claim 1,
a first power source and a second power source that supply power;
a first group of electrical devices and a second group of electrical devices that operate on power;
a first device that is driven by the power of the second power supply and temporarily generates power;
a switch unit capable of switching between a connection configuration in which a first power supply line that transmits power to the first electrical device group is connected to the first power supply, a second power supply line that transmits power to the second electrical device group is connected to the second power supply, and the first power supply line and the second power supply line are disconnected; and a connection configuration in which the first power supply line is connected to the second power supply, the second power supply line is connected to the first power supply, and the first power supply line and the second power supply line are disconnected;
a switch control unit for switching the switch unit;
It is an electric vehicle comprising

The invention according to claim 2 is the electric vehicle according to claim 1,
The switch control unit
selecting a first connection configuration in which the first power supply line is connected to the first power supply and the second power supply line to the second power supply, or a second connection configuration in which the first power supply line is connected to the second power supply and the second power supply line is connected to the first power supply, according to a vehicle state;
When driving the first device, the first power supply line and the second power supply line are disconnected in the selected first connection form or the second connection form.

The invention according to claim 3 is the electric vehicle according to claim 2,
The first electrical device group includes driving support devices that support driving,
The second electrical device group includes electrical devices that are driven while the vehicle is stopped or electrical devices that adjust the vehicle interior environment,
The switch control unit
The first power line and the second power line are disconnected in the first connection mode when the first device is driven while the vehicle is running, and the first power line and the second power line are disconnected in the second connection mode when the first device is driven while the vehicle is stopped.

The invention according to claim 4 is the electric vehicle according to claim 2 or claim 3,
The first device is an engine restart motor,
a device control unit that restarts the engine before executing the specific function when there is a request for execution of the specific function of the first electrical device group,
It is characterized by further comprising:

The invention according to claim 5 is the electric vehicle according to claim 3 or claim 4,
The switch section
a first switch that switches connection of the first power supply to the first power supply line or the second power supply line;
a second switch that switches connection of the second power supply to the first power supply line or the second power supply line;
a third switch that switches connection or disconnection between the first power line and the second power line;
The switch control unit
While driving without driving the first device, the first switch is connected to the first power supply line side, the second switch is connected to the second power supply line side, and the third switch is switched to the connection,
The first switch is connected to the second power supply line side, the second switch is connected to the first power supply line side, and the third switch is switched to the connection while the vehicle is stopped without driving the first device.

According to the present invention, the first power supply line and the second power supply line can be separated by the switch unit even when the power supply voltage of the second power supply drops significantly due to temporary power generation of the first device. Due to this disconnection, the first power supply line or the second power supply line connected to the first power supply is not affected by the voltage drop of the second power supply.

The resistance to large voltage drops in the power supply voltage (for example, resistance to momentary power failure) of electrical equipment mounted on an electric vehicle changes depending on the vehicle state, the external environment such as the outside temperature or weather, the road surface state, the driving mode selection state, or some other situation. For example, if there is a voltage drop while the vehicle is running, the desired functions of a driving support device or the like may not be obtained, or the driver may feel uncomfortable. On the other hand, if a voltage drop while the vehicle is stopped affects an automatic door opening/closing device, the desired function cannot be obtained or the driver feels uncomfortable. Therefore, according to the present invention, when the first power supply line and the second power supply line are disconnected by the switch section, the combination of connection between the first power supply and the second power supply and the first power supply line and the second power supply line can be selected from two combinations. These selections allow the first power supply line to be connected to the second power supply and the second power supply line to be connected to the first power supply in a situation where the first electrical equipment group is greatly affected by the voltage drop and the second electrical equipment group is not affected by the voltage drop. Conversely, in a situation where the voltage drop has a large effect on the second electrical equipment group and the voltage drop does not affect the first electrical equipment group, the first power supply line can be connected to the first power supply and the second power supply line can be connected to the second power supply. Since the connection form can be selected according to the situation, even if a voltage drop occurs in the second power supply, power can be supplied to both the first electrical device group and the second electrical device group without being affected by the voltage drop.

On the other hand, suppose that a configuration is adopted in which all other electric devices are connected to the first power supply when a voltage drop occurs in the second power supply. In this case, many electric devices may consume the power of the first power supply at the same time, so it becomes necessary to increase the output capacity of the first power supply. In addition, if a configuration is adopted in which an electrical device susceptible to voltage drop is left connected to the second power supply when a voltage drop occurs in the second power supply, the output performance of the second power supply needs to be improved so as to reduce the voltage drop in the second power supply. According to the present invention, even when a voltage drop occurs in the second power supply, the first electrical equipment group and the second electrical equipment group are connected to the first power supply and the second power supply in a distributed manner, and both the first electrical equipment group and the second electrical equipment group are not connected to only one power supply. Therefore, the output capacity and output performance required for the first power supply and the second power supply can be suppressed.

It is a figure showing the important section of the electric vehicle concerning Embodiment 1 of the present invention. 4 is a flowchart showing restart and power switching processing executed by the vehicle control unit of the first embodiment; 9 is a flowchart showing device control processing executed by a vehicle control unit according to Embodiment 2;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing essential parts of an electric vehicle according to Embodiment 1 of the present invention. An electric vehicle 1 according to Embodiment 1 of the present invention is a HEV (Hybrid Electric Vehicle) including an engine 7 and a travel motor 3 . The electric vehicle 1 includes drive wheels 2, a drive motor 3 and an engine 7 that generate power for the drive wheels 2, an inverter 4 that drives the drive motor 3 by inputting and outputting electric power, a first battery 5 that supplies power for running, an auxiliary machine 8 that drives the engine 7, a DC/DC converter 11 that generates a drive voltage for devices from the voltage of the first battery 5, a second battery 12 that outputs a drive voltage for devices, and an ISG (integrated starter) functioning as a restart motor for restarting the engine 7. 15, a first electrical device group 21 and a second electrical device group 22 that provide various functions of the electric vehicle 1, relays RL1 to RL3 for switching the connection form of the power supply, and a vehicle control unit 9 that controls the electric vehicle 1. The first battery 5 is a lithium ion secondary battery or the like and outputs a voltage higher than that of the second battery 12 . The second battery 12 is, for example, a lead-acid battery or a lithium-ion secondary battery, and outputs a power supply voltage for devices including auxiliary equipment such as a 12V system. Among the above configurations, the DC/DC converter 11 corresponds to an example of the first power supply according to the present invention. The second battery 12 corresponds to an example of a second power supply according to the invention. ISG15 is equivalent to an example of the 1st apparatus which concerns on this invention. The vehicle control section 9 corresponds to an example of a switch control section according to the present invention. The relays RL1 to RL3 correspond to examples of the switch section according to the present invention and the first to third switches according to the present invention.

The first electrical equipment group 21 is connected to the first power supply line L1 and operates by receiving power from the first power supply line L1. The first electric device group 21 includes driving support devices that support driving. More specifically, the first electrical device group 21 includes devices that operate mainly while the vehicle is running and are greatly affected by momentary power failures during operation. The first electrical device group 21 includes, for example, a skid prevention device 21a (also called VDC: Vehicle Dynamics Control), a collision mitigation braking system 21b, an electric power steering 21c, and a meter display system 21d that displays (vehicle speed, engine rotation speed, operation status of driving assistance functions, etc.) to assist driving operation. The sideslip prevention device 21a is a system that monitors whether or not the electric vehicle 1 skids, and adjusts the output of the brake and the power when the sideslip occurs to stabilize the behavior of the vehicle, and includes a sensor, a control circuit, and an actuator. The collision mitigation braking system 21b is a system that monitors the appearance of obstacles, warns the driver and assists braking based on the appearance of obstacles, and includes sensors, control circuits, and actuators.

The second electrical equipment group 22 is connected to the second power supply line L2 and operates by receiving power from the second power supply line L2. The second electrical equipment group 22 includes electrical equipment that operates mainly while the vehicle is stopped and does not operate while the vehicle is running, or electrical equipment that adjusts the vehicle interior environment. In other words, the second electrical equipment group 22 includes equipment that operates mainly while the vehicle is stopped but is greatly affected by an instantaneous power failure during operation, and equipment that operates while the vehicle is running or stopped but is less affected by an instantaneous power failure during operation. The second electrical equipment group 22 includes, for example, a power rear gate 22a, an electric parking brake 22b, an auxiliary display system 22c that displays auxiliary information such as outside temperature and room temperature on a meter panel, a rear defroster 22d that removes fogging from the rear window, a heat seat 22e that warms the seat, and a blower fan 22f that circulates air in the passenger compartment and air conditioning ducts.

The relay RL3 can switch connection and disconnection between the first power line L1 and the second power line L2. The relay RL3 employs a normally closed configuration in which, for example, it is switched to a disconnected state by excitation (output of excitation current to a control line) and switched to a connected state without excitation. With the normally closed configuration, power can be supplied to the vehicle control unit 9 when the system is stopped (when the ignition is turned off, that is, when the DC/DC converter 11 is stopped) regardless of whether the vehicle control unit 9 is connected to the first power line L1 or the second power line L2. However, the relay RL3 is not limited to this, and a normally open relay, a latch relay, a semiconductor switch (for example, a semiconductor switch having a parasitic diode, or a semiconductor switch connected in parallel with a diode), etc. may be employed as the relay RL3. If the relay RL3 is configured to be normally open, the relays RL1 and RL2 may be controlled to be in a predetermined switching state during system suspension. That is, the relays RL1 and RL2 should be switched so that the power line (the first power line L1 or the second power line L2) of the vehicle control unit 9 is connected to the second battery 12 when the system is stopped.

The relay RL1 is a three-pole relay that switches the connection destination of the DC/DC converter 11 to the first power line L1 or the second power line L2. The relay RL1 connects the DC/DC converter 11 to the second power supply line L2 by excitation, for example, and connects the DC/DC converter 11 to the first power supply line L1 without excitation. However, the relay RL1 is not limited to this, and a relay whose excitation and connection state are reversed, a latch relay, a semiconductor switch, or the like may be employed.

The relay RL2 is a three-pole relay that switches the connection destination of the second battery 12 to the first power line L1 or the second power line L2. The relay RL2 connects the second battery 12 to the first power supply line L1 by, for example, excitation, and connects the second battery 12 to the second power supply line L2 without excitation. However, the relay RL2 is not limited to this, and a relay whose excitation and connection state are reversed, a latch relay, a semiconductor switch, or the like may be employed.

The relays RL1 to RL3 switch their connection states based on the outputs of the excitation lines A and B from the vehicle control unit 9. FIG. One excitation line A is connected to the control lines of the two relays RL1 and RL2, and can excite the two relays RL1 and RL2 at the same time. The other excitation line B is connected to the control line of relay RL3 and can excite relay RL3.

パターン１は、本発明に係る第１接続形態の一例に相当し、パターン２は、本発明に係る第２接続形態の一例に相当する。 With such a configuration of the relays RL1 to RL3, as shown in the following pattern table A, it is possible to select from four power supply connection forms (denoted as "pattern 1" to "pattern 4"). In pattern 1 and pattern 2, the first power line L1 and the second power line L2 are separated by the non-excitation of the excitation line B, and the excitation or non-excitation of the excitation line A provides two connection configurations in which the first power line L1 and the second power line L2 are connected to the DC/DC converter 11 and the second battery 12 in different combinations. In patterns 3 and 4, excitation of the excitation line B connects the first power line L1 and the second power line L2. Therefore, both the DC/DC converter 11 and the second battery 12 are power sources that supply power to the first power line L1 and the second power line L2. Between patterns 3 and 4, there is no change in the relationship between the power supply destination and the power supply source. Pattern 3 and pattern 4 differ in the man-hours for switching relays RL1 to RL3 for transitioning to pattern 1 and the man-hours for switching relays RL1 to RL3 for transitioning to pattern 2. FIG. For example, a transition from pattern 3 to pattern 1 can be made by simply switching the output to excitation line B. A transition from pattern 4 to pattern 2 can be made only by switching the output to the excitation line B. FIG.

Pattern 1 corresponds to an example of a first connection form according to the present invention, and pattern 2 corresponds to an example of a second connection form according to the present invention.

The vehicle control unit 9 performs various controls of the electric vehicle 1, specifically, switching control of the relays RL1 to RL3, restart control of the engine 7 by driving the ISG 15, execution control of the function of each device of the first electric device group 21 and the second electric device group 22, drive control of controlling the driving force or braking force by controlling the auxiliary device 8 or the inverter 4 according to the driving operation of the driver. The vehicle control unit 9 may be composed of one ECU (Electronic Control Unit), or may be configured such that a plurality of ECUs communicate with each other and operate in cooperation with each other. The vehicle control unit 9 includes a ROM (Read Only Memory) that stores a control program and a CPU (Central Processing Unit) that performs calculation processing, and the CPU executes the control program to realize a plurality of functional modules. A plurality of functional modules can execute different control processes in parallel.

<Power supply switching control>
FIG. 2 is a flowchart showing restart and power switching processing executed by the vehicle control unit. The vehicle control unit 9 continuously executes the “restart and power switching process” in FIG. 2 during operation of the system of the electric vehicle 1 . In this process, first, the vehicle control unit 9 determines whether the electric vehicle 1 has switched from stopping to running or from running to stopped based on detection of the vehicle state (step S1). A stop means a state in which the vehicle speed is zero. Running means a state where the vehicle speed is other than zero. When the electric vehicle 1 is stopped, the engine 7 may be operating or may be stopped. When the vehicle state is running, the engine 7 may be operating or stopped (running by the running motor 3).

If it is determined in step S1 that there is no changeover between running and stopping, the vehicle control unit 9 jumps the process and determines whether or not there is a request to restart the engine 7 (step S4). The request to restart the engine 7 may be issued in parallel processing of another functional module realized by the vehicle control unit 9, or may be issued by the control units of the devices of the first electrical device group 21 and the second electrical device group 22. Further, a request to restart the engine 7 may occur both while the electric vehicle 1 is stopped and while it is running. While the vehicle is stopped, the engine 7 is requested to be restarted when, for example, a condition for canceling the idling stop is satisfied. During traveling, the restart of the engine 7 is required, for example, when switching from traveling driven by the traveling motor 3 to traveling driven by the engine 7 . If it is determined in step S4 that there is no request to restart the engine 7, the vehicle control unit 9 returns the process to step S1. Then, if the determination result of any of steps S1 and S4 is NO, these determination processes are repeated.

In the discrimination process of step S1, when there is a switch from traveling to stopping, the vehicle control unit 9 excites the excitation line A (step S2). Further, in the determination process of step S1, when the vehicle is switched from stop to running, the vehicle control unit 9 de-energizes the excitation line A (step S3).

When the excitation line A is excited in step S2, the connection of the relay RL1 is switched to the second power line L2 side, and the connection of the relay RL2 is switched to the first power line L1 side. At this time, the relay RL3 is in a state of connecting the first power line L1 and the second power line L2, the DC/DC converter 11 and the second battery 12 are connected to both the first power line L1 and the second power line L2, and the relationship between the power supply source and the power supply destination does not change. The process of step S2 is a process of switching the power supply connection form to pattern 4 of pattern table A, and is a preparatory process for enabling the power supply connection form to quickly transition to pattern 2 of pattern table A when the engine 7 is restarted while the vehicle is stopped.

When the excitation line A is de-excited in step S3, the connection of the relay RL1 is switched to the first power line L1 side, and the connection of the relay RL2 is switched to the second power line L2 side. At this time, the relay RL3 is in a state of connecting the first power line L1 and the second power line L2, the DC/DC converter 11 and the second battery 12 are connected to both the first power line L1 and the second power line L2, and the relationship between the power supply source and the power supply destination does not change. The process of step S3 is a process of switching the power supply connection form to pattern 3 of pattern table A, and is a preparatory process for enabling the power supply connection form to quickly transition to pattern 1 of pattern table A when the engine 7 is restarted while the vehicle is running.

Furthermore, when it is determined in the determination process of step S4 that there is a request to restart the engine 7, the vehicle control unit 9 first releases the excitation of the excitation line B (step S5). By releasing the excitation, the relay RL3 is switched to the disconnected state, and the first power line L1 and the second power line L2 are disconnected.

If the vehicle is stopped when the relay RL3 is switched in step S5, the power supply connection pattern has been switched to pattern 4 in the pattern table A in the previous step S2. Therefore, when step S5 is executed while the vehicle is stopped, the power supply connection mode is switched to pattern 2 in pattern table A, and the first power supply line L1 and the second power supply line L2 are disconnected in a state in which the second power supply line L2 is connected to the DC/DC converter 11 and the first power supply line L1 is connected to the second battery 12.

On the other hand, if the vehicle state is running when the relay RL3 is switched in step S5, the power supply connection pattern has been switched to pattern 3 of the pattern table A in the previous step S3. Therefore, when step S5 is executed while the vehicle is running, the power supply connection mode is switched to pattern 1 of the pattern table A, and the first power line L1 and the second power line L2 are disconnected with the first power line L1 connected to the DC/DC converter 11 and the second power line L2 connected to the second battery 12.

After switching the relay RL3, the vehicle control unit 9 drives the ISG 15 to restart the engine 7 (step S6). Since the ISG 15 temporarily consumes a large amount of electric power when the engine 7 is restarted, a large voltage drop occurs in the output of the second battery 12 . This voltage drop also extends to the power supply line (either the first power supply line L1 or the second power supply line L2) connected to the second battery 12 according to the connection pattern of the power supply.

However, when the vehicle is running, the voltage drop has little effect on the second electric device group 22 connected to the second battery 12 . The first electrical equipment group 21, which may cause inconvenience if a voltage drop occurs while the vehicle is running, is connected to the DC/DC converter 11 and supplied with a stable power supply voltage. Therefore, even if there is a voltage drop in the second battery 12, inconveniences such as restarting of any one of the first electric device group 21 and the second electric device group 22 used during running and being unable to provide a desired function are suppressed.

Further, when step S6 is executed while the vehicle is stopped, the first electric device group 21 connected to the second battery 12 is less affected by the voltage drop because the vehicle is stopped. Electrical devices that may cause problems if voltage drop occurs while the vehicle is stopped are connected to the DC/DC converter 11 and supplied with a stable power supply voltage. Therefore, even if there is a voltage drop in the second battery 12, inconveniences such as restarting of one of the first electric device group 21 and the second electric device group 22 used while the vehicle is stopped and being unable to provide a desired function are suppressed.

After completing the restart of the engine 7 in step S6, the vehicle control unit 9 excites the excitation line B (step S7) and switches the relay RL3 to the connected state. As a result, the first power line L1 and the second power line L2 are connected, and power can be supplied from the DC/DC converter 11 and the second battery 12 to both the first electric device group 21 and the second electric device group 22. Then, the vehicle control unit 9 returns the processing to step S1 and repeats the processing from step S1.

As described above, according to the electric vehicle 1 of Embodiment 1, the DC/DC converter 11 and the second battery 12, the ISG 15 that temporarily generates power, and the relays RL1 to RL3 that can switch the connection form of the power supply of the first power line L1 and the second power line L2. By switching the relays RL1 to RL3, the power supply connection forms of patterns 1 and 2 in the pattern table A can be realized. Therefore, even if a voltage drop occurs in the second battery 12 due to the drive of the ISG 15, the device group connected to the second battery 12 can be switched between a situation in which the voltage drop hardly affects the first electric device group 21 and a situation in which the voltage drop hardly affects the second electric device group 22. Therefore, a temporary voltage drop in the second battery 12 affects one of the first electrical device group 21 and the second electrical device group 22, and inconvenience such as not being able to obtain the requested operation can be suppressed. Furthermore, even if the connection form of the power supply is switched, the first electrical device group 21 and the second electrical device group 22 are not simultaneously connected only to the DC/DC converter 11 or connected only to the second battery 12 at the same time. Therefore, the required capacity of the DC/DC converter 11 and the second battery 12 can be kept low, and the cost of parts can be reduced.

Furthermore, according to the electric vehicle 1 of Embodiment 1, the vehicle control unit 9 switches the connection form of the power source between pattern 1 and pattern 2 of the pattern table A according to the vehicle state of the electric vehicle 1 . Furthermore, the electrical equipment that is susceptible to the drop in power supply voltage in a specific vehicle state and the electrical equipment that is susceptible to the drop in power supply voltage in another vehicle condition are divided into a first electrical equipment group 21 and a second electrical equipment group 22. Therefore, even if there is a temporary voltage drop in the second battery 12 due to the driving of the ISG 15, the second battery 12 is connected to a group of electric devices that are less susceptible to the voltage drop depending on the state of the vehicle, so that it is possible to suppress the voltage drop from affecting the electric devices and causing problems.

Furthermore, according to the electric vehicle 1 of Embodiment 1, the first electrical equipment group 21 includes driving support equipment that assists driving, and the second electrical equipment group 22 includes electrical equipment that is driven while the vehicle is stopped or electrical equipment that adjusts the vehicle interior environment. Further, the vehicle condition for selecting pattern 1 or pattern 2 in pattern table A as the power supply connection form for driving the ISG 15 is set to whether the vehicle is running or stopped. By adopting such a vehicle condition, by grouping the electrical devices as described above, the plurality of electrical devices provided in the electric vehicle 1 can be divided into two groups while avoiding inconveniences in all the electrical devices in the first electrical device group 21 and the second electrical device group 22 due to a temporary voltage drop in the second battery 12, and without biasing the total power consumption to one group.

Furthermore, according to the electric vehicle 1 of Embodiment 1, the vehicle control unit 9 switches the power supply connection form to pattern 3 or pattern 4 of the pattern table A from the stage where the ISG 15 is not driven, depending on the driving situation (steps S2 and S3 in FIG. 2). With such processing, when the ISG 15 is driven, the vehicle control unit 9 can realize switching to pattern 1 or pattern 2 (pattern table A) according to the vehicle state only by switching one relay RL3. Therefore, switching of the connection form of the power source according to the vehicle state can be realized promptly from the drive request of the ISG 15, and the delay in driving the ISG 15 can be suppressed.

(Embodiment 2)
FIG. 3 is a flowchart showing device control processing executed by a vehicle control unit according to the second embodiment. The electric vehicle 1 of the second embodiment has the same configuration as that of the first embodiment, and similarly executes the control process of the first embodiment. In addition, in the electric vehicle of Embodiment 2, the vehicle control unit 9 executes the device control process of FIG. 3 . The vehicle control section 9 of Embodiment 2 corresponds to an example of the switch control section and the device control section according to the present invention.

The vehicle control unit 9 always executes the device control process of FIG. 3 during the system operation of the electric vehicle 1 . In the device control process, the vehicle control unit 9 determines whether there is a request to execute the target function (step S11), and if there is no request to perform the target function, returns the process to step S1 and repeats this determination process. The target function corresponds to a specific function of the devices included in the first electrical device group 21, and corresponds to a function that consumes relatively large power due to temporary actuator driving, such as activation of emergency automatic braking in the collision mitigation braking system 21b. The execution request for the target function is issued by the control unit of the first electrical device group 21, for example, by a switch operation by the driver, or issued during parallel processing of other functional modules of the vehicle control unit 9.

As a result of the determination in step S11, if there is an execution request for the target function, the vehicle control unit 9 determines whether or not the engine 7 is stopped (step S12). The functions of the first electric device group 21 are executed while the vehicle is running, but may be executed while the engine 7 is stopped, such as while the vehicle is running by the traction motor 3 .

If the result of determination in step S12 is that the engine 7 is stopped, the vehicle control unit 9 requests restarting of the engine 7 (step S13). The restart request is passed to the "restart and power supply switching process" shown in FIG. 2, and the engine 7 is restarted within the process of FIG.

After the restart request, the vehicle control unit 9 confirms whether or not the engine 7 has completed restarting (step S14), and after confirming that the restarting has been completed, executes (or permits execution of) the target function (step S15).

In this way, when there is a request to execute a target function (a function of a device in the first electrical device group 21), the engine 7 is started first and then the target function is executed. This makes it possible to avoid driving the ISG 15, which consumes a large amount of power, and executing a specific function, which consumes a relatively large amount of power, at the same time. In the case of simultaneous execution, the electric device executing the target function consumes a large amount of power while being connected only to the DC/DC converter 11, but by shifting the execution timing, the electric device executing the target function consumes a large amount of power while being connected to both the DC/DC converter 11 and the second battery 12. Therefore, the target function can be stably executed.

If the result of determination in step S12 is that the engine 7 is not stopped, the vehicle control unit 9 determines whether the engine 7 is being restarted (step S16). If the vehicle is not being restarted, the vehicle control unit 9 shifts the process to step S15 to execute the target function, but if the vehicle is being restarted, the vehicle control unit 9 executes delay processing (waiting for a predetermined time) until the restart is completed (step S17), and then executes the target function (step S15).

The processing of steps S16 and S17 also avoids driving the ISG 15, which consumes a large amount of power, and executing a specific function, which consumes a relatively large amount of power, at the same time. Therefore, as described above, the electric device executing the target function can stably execute the target function while being connected to both the DC/DC converter 11 and the second battery 12 .

After executing the target function, the vehicle control unit 9 returns the process to step S1 and repeats the process from step S1.

Each embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiments. For example, in the above embodiment, an example in which the ISG 15 is applied as the first device that temporarily generates power was shown. However, the first device is not limited to the example of the embodiment as long as it is a device that temporarily generates power and consumes a large amount of power, such as an actuator that realizes automatic emergency braking. Therefore, the electric vehicle according to the present invention is not limited to a hybrid vehicle, and may be an electric vehicle that does not have an engine. Furthermore, in the above-described embodiment, as a condition for switching the combination of connections between the first power supply and the second power supply and the first power supply line L1 and the second power supply line L2, the vehicle condition of whether the vehicle is running or stopped is used. However, it is not limited to the example of the embodiment, and different conditions can be adopted, for example, when the road surface condition is bad such as rain or snow and when the road surface condition is good, or when an operation mode with high responsiveness is selected and when an operation mode with gentle responsiveness is selected. Furthermore, the first electrical equipment group and the second electrical equipment group may be grouped according to different conditions, such as equipment that is greatly affected by a momentary power failure in rain or snow, equipment that is greatly affected by a momentary power failure in sunny conditions, or equipment that is in a high-responsive operation mode and is greatly affected by a momentary power failure, and equipment that is in a slow-response operation mode and is greatly affected by a momentary power failure. Further, in the above-described embodiment, an example is shown in which the preparatory processes of steps S2 and S3 in FIG. 2 are executed in order to quickly switch the connection pattern of the power supply. In addition, the details shown in the embodiment, such as the specific configuration of the relays RL1 to RL3 as the switch section, can be changed as appropriate without departing from the gist of the invention.

REFERENCE SIGNS LIST 1 electric vehicle 3 traveling motor 7 engine 9 vehicle control unit (switch control unit, device control unit)
11 DC/DC converter (first power supply)
12 second battery (second power supply)
15 ISG (first device)
21 1st electrical equipment group 22 2nd electrical equipment group L1 1st power supply line L2 2nd power supply line RL1 to RL3 Relay (switch part)

Claims (5)

a first power source and a second power source that supply power;
a first group of electrical devices and a second group of electrical devices that operate on power;
a first device that is driven by the power of the second power supply and temporarily generates power;
a switch unit capable of switching between a connection configuration in which a first power supply line that transmits power to the first electrical device group is connected to the first power supply, a second power supply line that transmits power to the second electrical device group is connected to the second power supply, and the first power supply line and the second power supply line are disconnected; and a connection configuration in which the first power supply line is connected to the second power supply, the second power supply line is connected to the first power supply, and the first power supply line and the second power supply line are disconnected;
a switch control unit for switching the switch unit;
electric vehicle with The switch control unit
selecting a first connection configuration in which the first power supply line is connected to the first power supply and the second power supply line to the second power supply, or a second connection configuration in which the first power supply line is connected to the second power supply and the second power supply line is connected to the first power supply, according to a vehicle state;
2. The electric vehicle according to claim 1, wherein when the first device is driven, the first power line and the second power line are disconnected in the selected first connection mode or the second connection mode. The first electrical device group includes driving support devices that support driving,
The second electrical device group includes electrical devices that are driven while the vehicle is stopped or electrical devices that adjust the vehicle interior environment,
The switch control unit
3. The electric vehicle according to claim 2, wherein the first power line and the second power line are disconnected in the first connection mode when the first device is driven while the vehicle is running, and the first power line and the second power line are disconnected in the second connection mode when the first device is driven while the vehicle is stopped. The first device is an engine restart motor,
a device control unit that restarts the engine before executing the specific function when there is a request for execution of the specific function of the first electrical device group,
The electric vehicle according to claim 2 or 3, further comprising: The switch section
a first switch that switches connection of the first power supply to the first power supply line or the second power supply line;
a second switch that switches connection of the second power supply to the first power supply line or the second power supply line;
a third switch that switches connection or disconnection between the first power line and the second power line;
The switch control unit
While driving without driving the first device, the first switch is connected to the first power supply line side, the second switch is connected to the second power supply line side, and the third switch is switched to the connection,
While the vehicle is stopped without driving the first device, the first switch is connected to the second power supply line side, the second switch is connected to the first power supply line side, and the third switch is switched to the connection.
The electric vehicle according to claim 3 or 4, characterized in that:

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