WO2022044780A1 - Power supply system - Google Patents

Abstract

The present invention has electrical loads (34, 36), a first system (ES1) that includes a first power supply (10, 12), a second system (ES2) that includes a second power supply (16, 18), and an inter-system switch (SW1) that is provided on a connection path (LB) that connects the first system and the second system. The first power supply outputs a power supply voltage. The second power supply includes a plurality of storage batteries (16, 18). The present invention comprises an abnormality determination unit that determines whether an abnormality has occurred at the first system, a state control unit that opens the inter-system switch when the abnormality determination unit has determined that an abnormality has occurred, a first control unit that, when the plurality of storage batteries are to be charged, produces a first state in which the plurality of storage batteries are connected in parallel and power is supplied from the first power supply to the plurality of storage batteries, and a second control unit that, when the plurality of storage batteries are to be discharged, produces a second state in which the plurality of storage batteries are connected in series and power is supplied from the plurality of storage batteries to the electrical loads at a voltage that is higher than the power supply voltage of the first power supply or a voltage that is higher than a required voltage for the electrical loads.

Description

Power system Cross-reference of related applications

This application is based on Japanese Application No. 2020-141761 filed on August 25, 2020, and the contents of the description are incorporated herein by reference.

This disclosure relates to a power supply system.

In recent years, for example, a power supply system that is applied to a vehicle and supplies electric power to various devices of this vehicle is known. In this power supply system, when the vehicle is driven, an abnormality occurs in the system that supplies electric power to the electric load that performs the functions necessary for driving the vehicle, such as the electric brake device and the electric steering device, and the function is lost due to this. If you do, you will not be able to continue driving the vehicle. A device having a first power source and a second power source as a power source for supplying electric power to an electric load is known so as not to lose its function even when an abnormality occurs while the vehicle is in operation.

As a power supply system applied to this apparatus, for example, in Patent Document 1, a first power supply having a first load and a second load as an electric load for performing one function and including a first power supply connected to the first load is included. Those having a system and a second system including a second power source connected to the second load are known. In this power supply system, an inter-system switch is provided in the connection path connecting each system, and the inter-system switch is opened when the controller determines that an abnormality has occurred in one system. As a result, it is possible to secure the functions necessary for driving the vehicle by the electric load of the other system in which the abnormality has not occurred, and to continue the driving of the vehicle.

Japanese Unexamined Patent Publication No. 2019-62727

In the above power supply system, a configuration in which the second power supply of the second system is used as a storage battery can be considered. In such a configuration, for example, when the inter-system switch is opened due to an abnormality in the first system, power is supplied from the storage battery which is the second power source, but in a low temperature state or a high load state, for example, the first system is used. There is a concern that the electric load will not operate properly at the start of power supply from the storage battery in the two systems.

The present disclosure has been made to solve the above problems, and an object thereof is to provide a power supply system capable of appropriately supplying electric power to an electric load in a power supply system having a plurality of power supply systems. ..

The first means for solving the above-mentioned problems is an electric load, a first system including a first power source connected to the electric load, and a second system including a second power source connected to the electric load. A power supply system including an inter-system switch provided in a connection path connecting the first system and the second system to each other, wherein the first power supply is a power supply that enables driving of the electric load. The second power supply includes a plurality of storage batteries that can be charged by the power supply voltage of the first power supply, and has an abnormality determination unit for determining that an abnormality has occurred in the first system and an abnormality determination unit. When it is determined that an abnormality has occurred, the state control unit that opens the inter-system switch and the plurality of storage batteries are connected in parallel when charging the plurality of storage batteries, and the plurality of storage batteries are connected in parallel from the first power source. When the plurality of storage batteries are discharged, the first control unit in the first state of supplying power to the storage batteries of the above and the plurality of storage batteries are connected in series, and the voltage is higher than the power supply voltage of the first power supply. Alternatively, it includes a second control unit that is in a second state of supplying power to the electric load from the plurality of storage batteries at a voltage higher than the required voltage of the electric load.

According to the above configuration, a first system including a first power supply and a second system including a second power supply are provided. Therefore, redundant power supply by the first power supply and the second power supply becomes possible for the electric load. Further, an inter-system switch is provided in the connection path connecting the first and second systems to each other. Therefore, if it is determined that an abnormality has occurred in one of the systems, the switch between the systems is opened to operate the electric load by supplying power from the power supply of the other system in which the abnormality has not occurred. It is possible to continue.

Here, for example, when the inter-system switch is opened due to the occurrence of an abnormality in the first system, power is supplied from a plurality of storage batteries in the second power supply in the second system, and at that time, for example, in a low temperature state. It is desirable to keep the storage battery voltage of the second power supply high, considering that it may be in a high load state. However, on the other hand, in the configuration of charging the storage battery voltage to a high voltage, there is a concern that the power supply burden from the first power supply and the cost burden of the power supply system will increase.

In this respect, in the configuration of this means, when a plurality of storage batteries are charged, a plurality of storage batteries are connected in parallel, and when a plurality of storage batteries are discharged, a plurality of storage batteries are connected in series. In this case, when the plurality of storage batteries are charged, the plurality of storage batteries are connected in parallel, so that the power supply burden for charging and the cost burden of the power supply system can be reduced. Further, when power is supplied from a plurality of storage batteries in the second system due to an abnormality in the first system, a plurality of storage batteries are connected in series to have a voltage or an electric load higher than the power supply voltage of the first power supply. Since the electric load is supplied with a voltage higher than the required voltage, the electric load can be operated properly even in a low temperature state or a high load state. As a result, it is possible to properly supply electric power to an electric load in a power supply system having a plurality of power supply systems.

The second means is provided between the connection point with the connection path in the second system and the second power source, and includes a discharge control unit that regulates the discharge of the plurality of storage batteries in a series state.

In the above configuration, a discharge control unit is provided between the connection point with the connection path in the second system and the second power supply, and the discharge control unit regulates the discharge of a plurality of storage batteries in a series state. As a result, even if a plurality of storage batteries are placed in series, the electric charge stored in each of the storage batteries can be maintained. Further, by keeping each storage battery in series, it is possible to supply electric power from a plurality of storage batteries to an electric load at an early stage as needed.

In the third means, in the first state, the total voltage of the plurality of storage batteries becomes a voltage higher than the power supply voltage of the first power supply or a voltage higher than the required voltage of the electric load, and is in a fully charged state. A charge determination unit for determining that the battery is charged is provided, and the discharge regulation unit regulates the discharge of the plurality of storage batteries in a series state when the charge determination unit determines that the charge is fully charged.

In the above configuration, the discharge control unit regulates the discharge of multiple storage batteries in a series state and in a fully charged state. As a result, when an abnormality occurs in the first system, it is possible to supply power at a voltage higher than the power supply voltage of the first power supply or a voltage higher than the required voltage of the electric load at an early stage.

In the fourth means, the discharge control unit includes a battery switch that opens or closes a path between the connection point with the connection path and the second power supply in the second system, and the state control unit includes the state control unit. When it is determined by the abnormality determination unit that no abnormality has occurred, the inter-system switch is closed and the battery switch is opened to regulate the discharge of the plurality of storage batteries, and the abnormality determination unit is used. When it is determined that an abnormality has occurred, the inter-system switch is opened and the battery switch is closed to release the discharge restriction of the plurality of storage batteries.

In the above configuration, a battery switch is provided as a discharge control unit, and the inter-system switch and the battery switch are linked to open and close each based on the presence or absence of an abnormality in the first system. As a result, it is possible to properly manage the discharge of the storage battery of the second power source in both the normal state of the first system and the occurrence of an abnormality in the first system.

The fifth means is a power supply system mounted on a vehicle, wherein the electric load is a load that performs at least one function necessary for driving in the vehicle, and also performs a driving support function of the vehicle. The vehicle is capable of traveling in the first mode using the driving support function and traveling in the second mode without using the driving support function, and the first control unit is in the second mode. In the first state, the state control unit permits switching to the first mode when the discharge of the plurality of storage batteries is restricted by the discharge control unit.

In a power supply system applied to a vehicle having a first load and a second load as a function necessary for driving and performing a driving support function, driving and driving in the first mode using the driving support function and driving. Some can switch between driving in the second mode without using the support function. In the above configuration, the first state is set in the second mode, and when a plurality of storage batteries are fully charged in the second mode and discharge is restricted, switching to the first mode is permitted. As a result, even if an abnormality occurs in the first system in the first mode in which the driving support function is used, it is possible to continue driving the electric load using a plurality of fully charged storage batteries, and the driving support function Can be used continuously.

In the sixth means, the first path and the second path provided in parallel with each other between the connection point with the connection path and the second power supply in the second system, and the first path are provided. The discharge control unit includes a charging unit that charges a plurality of storage batteries connected in parallel to a voltage lower than the power supply voltage of the first power source by supplying power from the first power source, and the discharge regulating unit has the second path. To regulate the discharge of the plurality of storage batteries in the second system.

In the above configuration, the first path and the second path are provided in parallel with each other between the connection point with the connection path in the second system and the second power supply, and in the first path, the first path is provided by the charging unit. Multiple storage batteries are charged at a voltage lower than the power supply voltage of the power supply. Further, in the second path, the discharge regulating unit regulates the discharge of a plurality of storage batteries in the second system. By charging a plurality of storage batteries with a voltage lower than the power supply voltage of the first power supply, the charging unit can simplify the configuration of the power supply system related to the charging of the plurality of storage batteries and reduce the cost burden of the power supply system. be able to.

In the seventh means, the first path and the second path provided in parallel with each other between the connection point with the connection path and the second power supply in the second system, and the first path are provided. An open / close switch for opening or closing the first path is provided, and the discharge regulating unit is provided in the second path to regulate the flow of current from the connection point to the plurality of storage batteries in the second path. It also includes a rectifying element that causes a predetermined voltage difference between the voltage of the plurality of storage batteries connected in series and the power supply voltage.

In the above configuration, the first path and the second path are provided in parallel with each other between the connection point with the connection path in the second system and the second power supply, and the battery switch is closed in the first path. As a result, the plurality of storage batteries are charged, and when the battery switch is opened, the charging of the plurality of storage batteries is stopped. Further, a rectifying element as a discharge regulating unit is provided in the second path, and the rectifying element regulates the flow of current from the connection point to the plurality of storage batteries in the second path, and a plurality of connected in series. A predetermined voltage difference is created between the voltage of the storage battery and the voltage of the power supply. As a result, in the plurality of storage batteries in the series state, the state in which the voltage is higher than the power supply voltage of the first power supply is maintained. When an abnormality occurs in the first system, the voltage on the electric load side in the second system drops, and the batteries are discharged from a plurality of storage batteries connected in series, enabling early power supply to the electric load. It has become.

In the eighth means, the first control unit acquires the drive amount information indicating the drive amount of the electric load, and the second control unit has the drive amount indicated by the drive amount information more than a predetermined threshold value. When the state is switched from the small state to the large state, the second state is set.

With the occurrence of a ground fault in the first system, a voltage drop occurs in the electrical load. In addition to that, it is also conceivable that an excessive voltage drop of the electric load occurs due to a change in the driving amount of the electric load. In this respect, in the above configuration, the second state is set when the drive amount of the electric load is switched from the state smaller than the threshold value to the state larger than the threshold value. As a result, even if the drive amount of the electric load temporarily increases in the normal state of the first system, the electric load is properly operated by supplying power from a plurality of storage batteries connected in series. Can be done.

In the ninth means, when the first control unit switches from a state in which the drive amount indicated by the drive amount information is smaller than the threshold value to a state in which the drive amount is larger than the threshold value, and then from a state in which the drive amount is larger than the threshold value to a state in which the drive amount is smaller than the threshold value. In addition, the second state is switched to the first state, and the plurality of storage batteries are charged.

In the above configuration, when the drive amount of the electric load is switched from the state larger than the threshold value to the state smaller than the threshold value in the case where the second state is set in the normal state of the first system, the second state is switched to the first state. Changed to charge multiple storage batteries. Therefore, even when a plurality of storage batteries are temporarily discharged in the normal state of the first system, the plurality of storage batteries can be fully charged thereafter. Therefore, when an abnormality occurs in the first system, it is possible to continue driving the electric load by using a plurality of storage batteries in a fully charged state.

In the tenth means, the first control unit acquires the driving amount information indicating the driving amount of the electric load, and when the driving amount indicated by the driving amount information is smaller than a predetermined specified value, the plurality of said. The plurality of storage batteries are connected in parallel to charge the plurality of storage batteries individually, and when the drive amount indicated by the drive amount information is larger than the specified value, the plurality of storage batteries are connected in parallel to the plurality of storage batteries. Charge the storage battery at the same time.

In the first state, power supply to the electric load and power supply to a plurality of storage batteries are performed at the same time, so it is necessary to properly carry out these power supply. In this respect, in the above configuration, when the drive amount of the electric load is smaller than the specified value, a plurality of storage batteries are charged at the same time, and when the drive amount is larger than the specified value, the plurality of storage batteries are individually charged. did. By adjusting the number of storage batteries to be charged according to the amount of drive, it is possible to adjust the burden related to the power supply of the first power supply, and to properly supply power to the electric load and power to multiple storage batteries. can.

In the eleventh means, the plurality of storage batteries include a first specific battery and a second specific battery provided between a predetermined first potential point and a second potential point, and the positive electrode of the first specific battery. The terminal is connected to the first potential point by the first positive electrode side path and is connected to the second potential point by the first negative electrode side path, and the positive electrode terminal of the second specific battery is the second positive electrode. A first changeover switch provided in the first negative electrode side path, which is connected to the first potential point by the side path and is connected to the second potential point by the second negative electrode side path, and the second changeover switch. The second changeover switch provided in the positive electrode side path, the first connection point on the first specific battery side of the first negative electrode side path from the first changeover switch, and the second positive electrode side path. The first control unit includes, in the first state, the third changeover switch provided in the conduction path between the second changeover switch and the second connection point on the second potential point side. The first changeover switch and the second changeover switch are closed, the third changeover switch is opened, and the second control unit opens the first changeover switch and the second changeover switch in the second state. At the same time, the third changeover switch is closed, and the first control unit and the second control unit change the first changeover switch and the second changeover switch at the time of switching between the first state and the second state. The opening and closing of each changeover switch is controlled so that at least one of the switches and the third changeover switch are not closed at the same time.

When the first state in which the first specific battery and the second specific battery included in the plurality of storage batteries are connected in parallel and the second state in which the second specific battery is connected in series are switched, the first specific battery and the second specific battery are switched. When at least one of the first changeover switch and the second changeover switch connected in parallel and the third changeover switch connecting the first specific battery and the second specific battery in series are closed at the same time, the first specific battery and the second changeover battery are closed. There is a concern that at least one of the specified batteries will be short-circuited. In this regard, in the above configuration, when switching between the first state and the second state, each changeover switch is opened and closed so that at least one of the first changeover switch and the second changeover switch and the third changeover switch are not closed at the same time. I tried to control it. Thereby, the short circuit of the first specific battery and the second specific battery can be suppressed, and the first state and the second state can be appropriately switched.

The above objectives and other objectives, features and advantages of the present disclosure will be further clarified by the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is an overall configuration diagram of the power supply system of the first embodiment. FIG. 2 is a flowchart showing the procedure of the control process of the first embodiment. FIG. 3 is a time chart showing an example of the control process of the first embodiment. FIG. 4 is an overall configuration diagram of the power supply system of the second embodiment. FIG. 5 is a flowchart showing the procedure of the control process of the second embodiment. FIG. 6 is an overall configuration diagram of the power supply system according to the third embodiment. FIG. 7 is a flowchart showing the procedure of the control process of the third embodiment. FIG. 8 is a flowchart showing the procedure of the control process of the fourth embodiment.

(First Embodiment)
Hereinafter, an embodiment in which the power supply system according to the present disclosure is embodied as an in-vehicle power supply system 100 will be described with reference to the drawings.

As shown in FIG. 1, the power supply system 100 is a system that supplies electric power to a general load 30 and a specific load 32. The power supply system 100 includes a high-pressure storage battery 10, a DCDC converter (hereinafter referred to as a converter) 12, a first storage battery 14, a second storage battery 16 as a first specific battery, and a third storage battery 18 as a second specific battery. It includes a first switch unit 20, a relay switch SMR (system main relay switch), and a control device 40.

The high-voltage storage battery 10 has a rated voltage (for example, several hundred volts) higher than that of the first to third storage batteries 14 to 18, and is, for example, a lithium ion storage battery. The converter 12 is a voltage generation unit that converts the electric power supplied from the high-voltage storage battery 10 into the electric power of the power supply voltage VA and supplies it to the general load 30 and the specific load 32. In the present embodiment, the power supply voltage VA is a voltage that enables driving of the general load 30 and the specific load 32.

The general load 30 is an electric load (hereinafter, simply a load) that is not used for operation control in a vehicle as a mobile body, and is, for example, an air conditioner, an audio device, a power window, or the like.

On the other hand, the specific load 32 is a load that performs at least one function used for driving control of the vehicle, for example, an electric power steering device 50 that controls the steering of the vehicle, an electric brake device 51 that applies a braking force to the wheels, and the like. It is a traveling control device 52 or the like that monitors the situation around the vehicle. In this embodiment, the specific load 32 corresponds to the "electrical load".

Therefore, if an abnormality occurs in these specific loads 32 and all of their functions are lost, operation control cannot be performed. Therefore, the specific load 32 has a first load 34 and a second load 36 redundantly provided for each function so that all the functions are not lost even if an abnormality occurs. Specifically, the electric power steering device 50 has a first steering motor 50A and a second steering motor 50B. The electric brake device 51 has a first brake device 51A and a second brake device 51B. The travel control device 52 has a camera 52A and a laser radar 52B. The first steering motor 50A, the first brake device 51A, and the camera 52A correspond to the first load 34, and the second steering motor 50B, the second brake device 51B, and the laser radar 52B correspond to the second load 36. ..

The first load 34 and the second load 36 together realize one function, but each of them can realize a part of the function by itself. For example, in the electric power steering device 50, the first steering motor 50A and the second steering motor 50B allow the vehicle to be freely steered, and each steering motor 50A is subject to certain restrictions such as steering speed and steering range. , 50B enables steering of the vehicle.

Each specific load 32 realizes a function of supporting control by the driver in manual operation. Further, each specific load 32 realizes a function required for automatic driving in automatic driving that automatically controls behavior such as running and stopping of the vehicle. Therefore, the specific load 32 can also be said to be a load that performs at least one function necessary for driving the vehicle.

The first load 34 is connected to the converter 12 via the path LA1 in the first system, and the first storage battery 14 and the general load 30 are connected to the path LA1 in the first system. The first storage battery 14 is, for example, a lead storage battery. In the present embodiment, the first system ES1 is configured by the converter 12, the first storage battery 14, the general load 30, and the first load 34 connected by the path LA1 in the first system. In this embodiment, the high-voltage storage battery 10 and the converter 12 correspond to the "first power source".

Further, the second load 36 is connected to the second storage battery 16 and the third storage battery 18 via the path LA2 in the second system. The second storage battery 16 and the third storage battery 18 are, for example, lithium ion storage batteries. In the present embodiment, the second system ES2 is configured by the second storage battery 16, the third storage battery 18, and the second load 36 connected by the path LA2 in the second system. In this embodiment, the second storage battery 16 and the third storage battery 18 correspond to "a second power source and a plurality of storage batteries".

The first switch unit 20 is provided in the connection path LB that connects each system to each other. One end of the connection path LB is connected to the first intra-system path LA1 at the connection point PA, and the other end of the connection path LB is connected to the second intra-system path LA2 at the connection point PB. The first switch unit 20 includes a first switching element (hereinafter, simply the first switch) SW1. In this embodiment, an N-channel MOSFET (hereinafter, simply MOSFET) is used as the first switch SW1. In this embodiment, the first switch SW1 corresponds to an "intersystem switch".

The first current detection unit 27 is provided in the path LA1 in the first system, and the second current detection unit 28 is provided in the connection path LB. The first current detection unit 27 is provided in a portion of the path LA1 in the first system between the connection point PA and the first load 34, and detects the magnitude and direction of the current IA in the system flowing through the portion. do. The second current detection unit 28 is provided in the portion of the connection path LB on the first system ES1 side of the first switch unit 20, and detects the magnitude and direction of the inter-system current IB flowing through the portion.

The relay switch SMR is provided in a portion between the connection point PB in the path LA2 in the second system and the second storage battery 16 and the third storage battery 18, and the portion is opened or closed. By opening and closing the relay switch SMR, the second storage battery 16 and the third storage battery 18 can be switched between energization and energization cutoff. In this embodiment, the relay switch SMR corresponds to the "discharge control unit, battery switch".

The second storage battery 16 and the third storage battery 18 are configured to be rechargeable by the power supply from the converter 12. Specifically, by closing the first switching element SW1 and the relay switch SMR, the second storage battery 16 and the third storage battery 18 are charged by the power supply voltage VA.

The control device 40 generates a first switching signal SC1 in order to switch the first switch SW1 based on the detection values of the first and second current detection units 27 and 28, and issues a command by the first switching signal SC1. Output to the first switch SW1. Further, the control device 40 generates a relay switching signal SR in order to switch the relay switch SMR, and outputs a command by the relay switching signal SR to the relay switch SMR. Further, the control device 40 generates a control signal SD in order to control the operation of the converter 12, and outputs a command by the control signal SD to the converter 12. The operation state and the operation stop state of the converter 12 are switched by the control signal SD.

Further, the control device 40 is connected to the notification unit 44, the IG switch 45, and the input unit 46, and controls these. The notification unit 44 is a device that visually or audibly notifies the driver, and is, for example, a display or a speaker installed in a vehicle interior. The IG switch 45 is a vehicle start switch. The control device 40 monitors the opening or closing of the IG switch 45. The input unit 46 is a device that accepts the operation of the driver, for example, a handle, a lever, a button, a pedal, and a voice input device.

The control device 40 manually drives and automatically drives the vehicle using the above-mentioned specific load 32. The control device 40 includes a well-known microcomputer including a CPU, ROM, RAM, flash memory, and the like. The CPU realizes various functions for manual operation and automatic operation by referring to the arithmetic program and control data in the ROM.

Note that manual driving represents a state in which the vehicle is controlled by the operation of the driver. Further, the automatic driving represents a state in which the vehicle is driven and controlled by the control content by the control device 40 regardless of the operation of the driver. Specifically, automatic driving refers to automatic driving of level 3 or higher among the automatic driving levels from level 0 to level 5 defined by the National Highway Traffic Safety Administration (NHTSA). Level 3 is a level at which the control device 40 controls both steering wheel operation and acceleration / deceleration while observing the traveling environment.

Further, the control device 40 can implement driving support functions such as LKA (Lane Keeping Assist), LCA (Lane Change Assist), and PCS (Pre-Crash Safety) by using the specific load 32 described above. The control device 40 can switch the driving mode of the vehicle between a first mode in which the driving support function is used and a second mode in which the driving support function is not used, and the vehicle can travel in each driving mode. .. The control device 40 switches between the first mode and the second mode according to the driver switching instruction via the input unit 46. Here, the first mode includes a mode in which the driver manually drives the vehicle using the driving support function, and a mode in which the vehicle is automatically driven. The second mode is a mode in which the driver manually drives the vehicle without using the driving support function.

In the first mode, the control device 40 determines whether or not an abnormality has occurred in the first system ES1 and the second system ES2, and if it is determined that no abnormality has occurred in any of the systems ES1 and ES2, Automatic driving and driving support of the vehicle are performed using the first load 34 and the second load 36. As a result, the first and second loads 34 and 36 cooperate to carry out one function necessary for automatic driving and driving support. In the present embodiment, the abnormality is a power failure abnormality such as a ground fault or a disconnection.

On the other hand, if it is determined that an abnormality has occurred in either of the systems ES1 and ES2, the first switch SW1 is opened to electrically insulate the first system ES1 and the second system ES2. As a result, even if an abnormality occurs in one of the systems ES1 and ES2, the loads 34 and 36 of the other system ES1 and ES2 in which the abnormality has not occurred can be driven.

By the way, when the first switch SW1 is opened due to the occurrence of an abnormality in the first system ES1, power is supplied from the second storage battery 16 and the third storage battery 18 to the second load 36 in the second system ES2. Will be. However, when the power supply system 100 is used in a low temperature state or a high load state, the performance of the second storage battery 16 and the third storage battery 18 deteriorates, and the wiring resistance in the path LA2 in the second system increases, so that the second storage battery It is desirable to keep the storage battery voltage VB of 16 and the third storage battery 18 high. However, on the other hand, when the storage battery voltage VB is charged to a high voltage, there is a concern that the power supply burden and the cost burden from the converter 12 will increase.

In the present embodiment, in the second system ES2, the second storage battery 16 and the third storage battery 18 can be switched between a state in which they are connected in series and a state in which they are connected in parallel. Specifically, the positive electrode terminal of the second storage battery 16 is connected to the relay switch SMR by the first positive electrode side path LC1, and the negative electrode terminal of the second storage battery 16 is connected to the ground by the first negative electrode side path LD1. ing. The positive electrode terminal of the third storage battery 18 is connected to the first positive electrode side path LC1 at the connection point PC by the second positive electrode side path LC2, and the negative electrode terminal of the second storage battery 16 is connected to the connection point by the second negative electrode side path LD2. In PD, it is connected to the first negative electrode side path LD1. That is, the second storage battery 16 and the third storage battery 18 are connected in parallel between the connection point PC and the connection point PD by the first and second positive electrode side paths LC1 and LC2 and the first and second negative electrode side paths LD1 and LD2. Has been done. In the present embodiment, the connection point PC corresponds to the "first potential point", and the connection point PD corresponds to the "second potential point".

Further, in the path LA2 in the second system, the second switch unit 22 is provided on the second storage battery 16 and the third storage battery 18 side of the relay switch SMR. The second switch unit 22 includes second to fourth switching elements (hereinafter, simply second to fourth switches) SW2 to SW4. The second switch SW2 is provided in the first negative electrode side path LD1, and the third switch SW3 is provided in the second positive electrode side path LC2.

The fourth switch SW4 is provided in the conduction path LE connecting the second positive electrode side path LC2 and the first negative electrode side path LD1. One end of the conduction path LE is connected between the second storage battery 16 and the second switch SW2 of the first negative electrode side path LD1 at the connection point PE, and the other end of the conduction path LE is at the connection point PF. 2 Of the positive electrode side paths LC2, the third switch SW3 and the third storage battery 18 are connected to each other. In the present embodiment, the connection point PE corresponds to the "first connection point", and the connection point PF corresponds to the "second connection point".

In this embodiment, MOSFETs are used as the second to fourth switches SW2 to SW4. The control device 40 generates the second to fourth switching signals SC2 to SC4 in order to switch the second to fourth switches SW2 to SW4, and issues commands from the second to fourth switching signals SC2 to SC4 to the second to the second. Output to the 4th switch SW2 to SW4. In the present embodiment, the second switch SW2 corresponds to the "first changeover switch", the third switch SW3 corresponds to the "second changeover switch", and the fourth switch SW4 corresponds to the "third changeover switch". do.

The control device 40 switches between a state in which the second storage battery 16 and the third storage battery 18 are connected in parallel and a state in which they are connected in series by the second to fourth switching signals SC2 to SC4. Specifically, the second and third switches SW2 and SW3 are closed, and the fourth switch SW4 is opened, so that the second storage battery 16 and the third storage battery 18 are connected in parallel. On the other hand, when the second and third switches SW2 and SW3 are opened and the fourth switch SW4 is opened, the second storage battery 16 and the third storage battery 18 are connected in series.

Then, in the present embodiment, when the second storage battery 16 and the third storage battery 18 are charged by the power supply from the converter 12, the second storage battery 16 and the third storage battery 18 are connected in parallel. Further, when the second storage battery 16 and the third storage battery 18 are discharged, the opening or closing of the second to fourth switches SW2 to SW4 is controlled so that the second storage battery 16 and the third storage battery 18 are connected in series. The control process is now executed.

In this case, when the second storage battery 16 and the third storage battery 18 are charged, the second storage battery 16 and the third storage battery 18 are connected in parallel, and the second storage battery 16 and the third storage battery 18 are connected without boosting the power supply voltage VA. 18 is charged. This makes it possible to reduce, for example, the power supply burden of the converter 12 in charging and the cost burden of the power supply system 100 by providing the boost converter in the second system ES2. Further, when the power is supplied from the second storage battery 16 and the third storage battery 18 in the second system ES2 due to the occurrence of an abnormality in the first system ES1, the second storage battery 16 and the third storage battery 18 are connected in series. Power is supplied to the loads 34 and 36 at a voltage higher than the power supply voltage VA. As a result, the second load 36 can be properly operated even in a low temperature state or a high load state.

FIG. 2 shows a flowchart of the control process of the present embodiment. When the IG switch 45 is closed, the control device 40 repeatedly executes the control process at predetermined control cycles. At the beginning of closing the IG switch 45, the operation mode of the vehicle is set to the second mode, the first switch SW1 is closed, and the converter 12 is in the operating state.

When the control process is started, first, in step S10, it is determined whether or not the driving mode of the vehicle is the second mode. If affirmative determination is made in step S10, the remaining capacity SA of the second storage battery 16 and the third storage battery 18 is calculated in step S12. The remaining capacity SA is, for example, the total value of SOC (State Of Charge) indicating the state of charge of each of the storage batteries 16 and 18. When the second storage battery 16 and the third storage battery 18 are in the energized state (charged state or discharged state), the remaining capacity SA uses the current integrated value which is the time integrated value of the charge / discharge current of each of the storage batteries 16 and 18. Is calculated.

In step S14, it is determined whether or not the remaining capacity SA calculated in step S12 is larger than the predetermined capacity threshold value Sth. Here, the capacity threshold Sth is a capacity at which the total voltage of the second storage battery 16 and the third storage battery 18 becomes a voltage higher than the power supply voltage VA by a predetermined value. When the remaining capacity SA is smaller than the capacity threshold Sth, the total voltage of the second storage battery 16 and the third storage battery 18 is not higher than a predetermined value than the power supply voltage VA, and the second storage battery 16 and the third storage battery 18 are fully charged. Not in a state. In this case, since the precondition for executing the first mode is not satisfied, a negative determination is made in step S14, and the process proceeds to steps S42 and S44.

On the other hand, when the remaining capacity SA is larger than the capacity threshold Sth, the total voltage of the second storage battery 16 and the third storage battery 18 is higher than the power supply voltage VA by a predetermined value or more, and the second storage battery 16 and the third storage battery 18 are full. It is in a charged state. In this case, since the precondition for executing the first mode is satisfied, an affirmative determination is made in step S14. In this case, in step S16, the relay switch SMR is opened to stop the charging of the second storage battery 16 and the third storage battery 18. As will be described later, when the affirmative determination is made in step S14, the relay switch SMR is closed. In this embodiment, the process of step S14 corresponds to the "charge determination unit".

In the following step S17, the second storage battery 16 and the third storage battery 18 are switched to the series connection by opening the second and third switches SW2 and SW3 and closing the fourth switch SW4. In switching to series connection, the 4th switch SW4 is closed after opening the 2nd and 3rd switches SW2 and SW3, and at least one of the 2nd and 3rd switches SW2 and SW3 and the 4th switch SW4 are not closed at the same time. To do so.

By connecting the second storage battery 16 and the third storage battery 18 in series, the storage battery voltage VB of the second storage battery 16 and the third storage battery 18 is substantially doubled. In the present embodiment, the relay switch SMR is opened prior to the series connection of the second storage battery 16 and the third storage battery 18, so that the discharge of the second storage battery 16 and the third storage battery 18 in the series connection is restricted. Will be done.

In the following step S18, the operation mode of the vehicle is allowed to be switched from the second mode to the first mode, and the control process is terminated. The switching to the first mode is performed, for example, when a switching instruction such as an instruction to use the driving support function or an instruction for automatic driving is input from the driver via the input unit 46.

On the other hand, if a negative determination is made in step S10, it is determined in step S20 whether the driver is being notified. Here, the driver notification notifies the driver that an abnormality has occurred in either the first system ES1 or the second system ES2, informs the driver that the first mode is to be canceled, and switches to the second mode. Is to encourage.

If a negative determination is made in step S20, it is determined that an abnormality has occurred in either the first system ES1 or the second system ES2 in steps S22 and S24. Specifically, in step S22, it is determined whether or not an abnormality has occurred in the first system ES1. If a negative determination is made in step S22, it is determined in step S24 whether or not an abnormality has occurred in the second system ES2. In this embodiment, the process of step S22 corresponds to the "abnormality determination unit".

The occurrence of an abnormality can be determined by the magnitude of each of the currents IA and IB detected by the first and second current detection units 27 and 28. For example, when a ground fault occurs in the first system ES1, the magnitude of the in-system current IA detected by the first current detection unit 27 is equal to or larger than a predetermined current threshold value Is for determining the ground fault. Further, for example, when a ground fault occurs in the second system ES2, the magnitude of the inter-system current IB detected by the second current detection unit 28 becomes equal to or larger than the current threshold value Is. Therefore, it is possible to determine which system ES1 or ES2 the abnormality has occurred based on the magnitude of each of the currents IA and IB detected by the first and second current detection units 27 and 28.

If it is determined that no abnormality has occurred in any of the systems ES1 and ES2, a negative determination is made in step S24. In this case, the control process is terminated. As a result, the power supply from the converter 12 to the first and second loads 34 and 36 is continued, and the relay switch SMR is maintained in an open state. That is, when it is determined that no abnormality has occurred in any of the systems ES1 and ES2, and it is determined that the second storage battery 16 and the third storage battery 18 are in a fully charged state, the first switch SW1 is closed and the relay is relayed. The switch SMR is released. As a result, unnecessary discharge from the second storage battery 16 and the third storage battery 18 is suppressed.

On the other hand, when it is determined that an abnormality has occurred in either of the systems ES1 and ES2, the power supply to the system side where the abnormality has occurred is stopped and the power supply to the electric load of the system where the abnormality has not occurred. Carry out the process of continuing.

Specifically, if an affirmative determination is made in step S22, first, in step S26, the first switch SW1 is opened. In the following step S28, the relay switch SMR is closed to release the discharge suppression of the second storage battery 16 and the third storage battery 18. In the present embodiment, the process of step S26 corresponds to the "state control unit", and the process of steps S26 and 28 corresponds to the "second control unit".

As a result, with the second storage battery 16 and the third storage battery 18 connected in series, power is supplied from the second storage battery 16 and the third storage battery 18 to the second load 36, and the second storage battery 16 and the third storage battery 18 are supplied. Is in the second state of being discharged. In this case, since the second storage battery 16 and the third storage battery 18 are connected in series, power is supplied to the second load 36 at a voltage higher than the power supply voltage VA. In the following step S30, a command to put the converter 12 into the operation stop state is output.

Further, if an affirmative determination is made in step S24, the first switch SW1 is opened in step S32. As a result, the power supply from the converter 12 in the first system ES1 to the first load 34 is continued.

After that, in step S36, the driver is notified via the notification unit 44 that the first mode is to be stopped, and the control process is terminated.

If an affirmative determination is made in step S20, it is determined in step S38 whether or not a switching instruction to the second mode has been input from the driver via the input unit 46. That is, it is determined whether or not there is a response from the driver in response to the notification. If a negative determination is made in step S38, the control process is terminated, and the vehicle runs in the first mode using the loads 34 and 36 on the system side where no abnormality has occurred.

On the other hand, if an affirmative determination is made in step S38, the driving mode of the vehicle is switched from the first mode to the second mode in step S40, and the control process is terminated.

In steps S42 and S44, that is, when the driving mode of the vehicle is the second mode, it is determined that an abnormality has occurred in either the first system ES1 or the second system ES2. Specifically, in step S42, it is determined whether or not an abnormality has occurred in the first system ES1. If a negative determination is made in step S42, it is determined in step S44 whether or not an abnormality has occurred in the second system ES2.

If it is determined that no abnormality has occurred in any of the systems ES1 and ES2, a negative determination is made in step S44. In this case, in step S45, the second storage battery 16 and the third storage battery 18 are switched to parallel connection by closing the second and third switches SW2 and SW3 and opening the fourth switch SW4. In switching to parallel connection, the second and third switches SW2 and SW3 are closed after the fourth switch SW4 is opened, and at least one of the second and third switches SW2 and SW3 and the fourth switch SW4 are not closed at the same time. To do so.

In the following step S46, the relay switch SMR is closed and the control process is terminated. In this embodiment, the processes of steps S45 and S46 correspond to the "first control unit".

As a result, with the second storage battery 16 and the third storage battery 18 connected in parallel, power is supplied from the converter 12 to the second storage battery 16 and the third storage battery 18, and the second storage battery 16 and the third storage battery 18 are charged. It becomes the first state to be done. That is, when the driving mode of the vehicle is the second mode, the first state is set, and the process of step S14 described above is also performed in the first state.

On the other hand, when it is determined that an abnormality has occurred in either of the systems ES1 and ES2, the power supply to the system side where the abnormality has occurred is stopped and the power supply to the electric load of the system where the abnormality has not occurred. Carry out the process of continuing.

Specifically, if an affirmative determination is made in step S42, first, in step S47, the first switch SW1 is opened. In the following step S48, the second storage battery 16 and the third storage battery 18 are connected in series. As a result, a higher voltage can be discharged as compared with the case where the second storage battery 16 and the third storage battery 18 are connected in parallel. In the following step S50, a command to put the converter 12 into the operation stop state is output.

Further, if an affirmative determination is made in step S44, the first switch SW1 is opened in step S52. In the following step S54, the relay switch SMR is opened.

After that, in step S56, the driver is notified via the notification unit 44 that an abnormality has occurred in either the first system ES1 or the second system ES2, and the control process is terminated.

Subsequently, FIG. 3 shows an example of control processing. FIG. 3 shows the transition between the load voltage VD and the storage battery voltage VB when a ground fault abnormality (hereinafter, simply ground fault) occurs in the first system ES1 while the vehicle is running in the first mode. Here, the load voltage VD indicates the voltage applied to the second load 36, specifically, the voltage of the connection point PB in the second system ES2. Further, the storage battery voltage VB indicates the voltage between the terminals of the second storage battery 16 and the third storage battery 18, and specifically, the connection point PC between the first positive electrode side path LC1 and the second positive electrode side path LC2 in the second system ES2. Indicates the voltage of. Therefore, the storage battery voltage VB when the second storage battery 16 and the third storage battery 18 are connected in series is twice the voltage of the storage battery voltage VB when the second storage battery 16 and the third storage battery 18 are connected in parallel. Become.

In FIG. 3, (A) shows the transition of the state of the IG switch 45, (B) shows the transition of the operation mode of the vehicle, and (C) shows the transition of the open / closed state of the first switch SW1. (D) shows the transition of the open / closed state of the relay switch SMR, (E) shows the transition of the open / closed state of the second and third switches SW2 and SW3, and (F) shows the transition of the open / closed state of the fourth switch SW4. Shows the transition of. Further, (G) shows the transition of the connection state of the second storage battery 16 and the third storage battery 18, (H) shows the transition of the load voltage VD, and (I) shows the transition of the storage battery voltage VB. (J) shows the transition of the in-system current IA in the first system ES1.

As shown in FIG. 3, in the open period of the IG switch 45 until the time t1, that is, in the hibernation state of the power supply system 100, the first to fourth switches SW1 to SW4 and the relay switch SMR are open, and the converter 12 operates. It has been switched to the stopped state. Therefore, during the opening period of the IG switch 45, the load voltage VD and the in-system current IA become zero.

When the IG switch 45 is closed at time t1, the first switch SW1 is closed and a command for switching the converter 12 to the operating state is output. As a result, the converter 12 is switched to the operating state, the load voltage VD rises to a predetermined operating voltage VM as the power supply voltage VA rises, and the vehicle can run in the second mode. Here, the operating voltage VM is a voltage within the drive voltage range of the first and second loads 34 and 36.

In addition, the second and third switches SW2 and SW3 are closed, and the relay switch SMR is closed. As a result, in a state where the second storage battery 16 and the third storage battery 18 are connected in parallel, the first state is set in which the converter 12 is charged by the power supply voltage VA. Then, the storage battery voltage VB rises to a predetermined boosted voltage VH (see FIG. 3 (I)). Here, the boosted voltage VH is a voltage at which the second storage battery 16 and the third storage battery 18 are in a fully charged state, and is a voltage lower than the operating voltage VM and higher than half of the operating voltage VM.

When the storage battery voltage VB rises to the boost voltage VH at time t2 and the second storage battery 16 and the third storage battery 18 are in a fully charged state, the relay switch SMR is released. Further, the second and third switches SW2 and SW3 are opened at time t3 after the relay switch SMR is opened. As a result, the second storage battery 16 and the third storage battery 18 are in a disconnected state in which all of the second to fourth switches SW2 to SW4 are open.

Then, the fourth switch SW4 is closed at time t4 after the second and third switches SW2 and SW3 are opened. When the 4th switch SW4 is closed after the 2nd and 3rd switches SW2 and SW3 are opened, at least one of the 2nd and 3rd switches SW2 and SW3 and the 4th switch SW4 are erroneously closed at the same time. It is possible to prevent short-circuiting of at least one of the second storage battery 16 and the third storage battery 18.

Further, when the fourth switch SW4 is closed, the second storage battery 16 and the third storage battery 18 are connected in series, and in the state of being connected in series, the discharge is regulated by the relay switch SMR. As a result, the storage battery voltage VB becomes an additional voltage of 2 VH, which is the sum of the boosted voltages VH of the storage batteries 16 and 18.

When the second storage battery 16 and the third storage battery 18 are connected in series and the discharge is regulated by the relay switch SMR, the operation mode of the vehicle can be switched from the second mode to the first mode. In FIG. 3, the driving mode of the vehicle is switched from the second mode to the first mode at time t4.

It is determined that a ground fault has occurred in either the first system ES1 or the second system ES2 while the vehicle is running in the first mode. When it is determined that no ground fault has occurred in any of the systems ES1 and ES2, the first switch SW1 is maintained in the closed state. As a result, electric power can be supplied from the converter 12 and the first storage battery 14 to the first and second loads 34 and 36, respectively. The power supply from the converter 12 enables continuous power supply even during long-term automatic operation, and the power supply from the first storage battery 14 enables power supply with less voltage fluctuation. As a result, in the period from time t4 to time t5, automatic operation and driving support using the first load 34 and the second load 36 are performed.

If it is determined that a ground fault has occurred in either of the systems ES1 and ES2, the first switch SW1 is closed. In FIG. 3, a ground fault occurs in the first system ES1 at time t5. As a result, the power supply voltage VA and the load voltage VD decrease.

Further, the in-system current IA increases, and at the subsequent time t6, the in-system current IA becomes equal to or higher than the current threshold value Is. As a result, it is determined that a ground fault has occurred in the first system ES1. In this case, at time t6, the first switch SW1 is opened and the converter 12 is switched to the operation stop state. This reduces the in-system current IA.

Also, at this time t6, the relay switch SMR is closed. As a result, the load voltage VD rises due to the power supply from the second storage battery 16 and the third storage battery 18 to the second load 36. In the present embodiment, when a ground fault occurs in the first system ES1, the storage battery voltage VB rises to an added voltage of 2 VH higher than the boosted voltage VH, so that the load voltage VD rises to an added voltage of 2 VH. Therefore, a predetermined voltage difference ΔV can be secured between the load voltage VD and the threshold voltage Vth which is the lower limit of the drive voltage of the first and second loads 34 and 36. As a result, the second load 36 can be properly operated even in a low temperature state or a high load state.

Further, in the present embodiment, when a ground fault occurs in the first system ES1, the second storage battery 16 and the third storage battery 18 are connected in series. Therefore, when a ground fault occurs in the first system ES1, power can be supplied to the second load 36 at an early stage.

After that, when the driver inputs an instruction to switch to the second mode via the input unit 46, the driving mode of the vehicle is switched from the first mode to the second mode at time t7.

According to the present embodiment described in detail above, the following effects can be obtained.

In the present embodiment, when the second storage battery 16 and the third storage battery 18 are charged, the second storage battery 16 and the third storage battery 18 are connected in parallel, and the second storage battery 16 and the third storage battery 18 are discharged. The second storage battery 16 and the third storage battery 18 are connected in series. In this case, when the second storage battery 16 and the third storage battery 18 are charged, the second storage battery 16 and the third storage battery 18 are connected in parallel, so that the power supply burden for charging and the cost of the power supply system 100 are set. The burden can be reduced. Further, when the power is supplied from the second storage battery 16 and the third storage battery 18 in the second system ES2 due to the occurrence of an abnormality in the first system ES1, the second storage battery 16 and the third storage battery 18 are connected in series. Since the power is supplied to the loads 34 and 36 at a voltage higher than the power supply voltage VA, the second load 36 can be properly operated even in a low temperature state or a high load state. As a result, in the power supply system 100 having a plurality of systems ES1 and ES2, power can be appropriately supplied to the loads 34 and 36.

A second state in which the second storage battery 16 and the second storage battery 18 are connected in parallel when the first state in which the second storage battery 16 and the second storage battery 18 are connected in parallel and the second state in which the second storage battery 18 is connected in series can be switched. , At least one of the second storage battery 16 and the second storage battery 18 when at least one of the third switches SW2 and SW3 and the fourth switch SW4 for connecting the second storage battery 16 and the second storage battery 18 in series are closed at the same time. Is concerned that it will be short-circuited. In this respect, in the present embodiment, when switching between the first state and the second state, at least one of the second and third switches SW2 and SW3 and the fourth switch SW4 are not closed at the same time, so that the switches SW2 to SW4 are not closed at the same time. Changed to control the opening and closing of. As a result, it is possible to suppress a short circuit between the second storage battery 16 and the second storage battery 18 and appropriately switch between the first state and the second state.

In the present embodiment, a relay switch SMR is provided between the connection point PB in the second system ES2 and the second storage battery 16 and the third storage battery 18, and the second storage battery 16 and the second storage battery 16 in a series state are provided by the relay switch SMR. The discharge of the third storage battery 18 is regulated. As a result, even if the second storage battery 16 and the third storage battery 18 are in a series state, the electric charge stored in the second storage battery 16 and the third storage battery 18 can be maintained. Further, by keeping the second storage battery 16 and the third storage battery 18 in series, electric power can be supplied from the second storage battery 16 and the third storage battery 18 to the loads 34 and 36 at an early stage as needed.

-In particular, in this embodiment, the relay switch SMR is configured to regulate the discharge of a plurality of storage batteries in a series state and a fully charged state. As a result, when an abnormality occurs in the first system ES1, it is possible to supply power with an additional voltage of 2 VH, which is higher than the power supply voltage VA, at an early stage.

-In this embodiment, the first switch SW1 and the relay switch SMR are linked to open and close each of them based on the presence or absence of an abnormality in the first system ES1. As a result, the discharges of the second storage battery 16 and the third storage battery 18 can be properly managed both when the first system ES1 is normal and when an abnormality occurs in the first system ES1.

The power supply system 100 is applied to a vehicle having a first load 34 and a second load 36 as a specific load 32 that is a function necessary for driving and implements a driving support function, and is a first method that uses the driving support function. It is possible to switch between driving in a mode and driving in a second mode that does not use the driving support function. In the present embodiment, in the second mode, the second storage battery 16 and the third storage battery 18 are connected in parallel, and in the state of being connected in parallel, the first state is set to be charged by the power supply voltage VA of the converter 12. Then, when the second storage battery 16 and the third storage battery 18 are fully charged in the second mode and the discharge is restricted, the switching to the first mode is permitted. As a result, even if an abnormality occurs in the first system ES1 in the first mode in which the driving support function is used, the second load 36 can be driven by using the second storage battery 16 and the third storage battery 18 in the fully charged state. It can be continued, and the driving support function can be used continuously.

(Variation example of the first embodiment)
The relay switch SMR may not be provided in the second system ES2. In this case, the control device 40 can control the charging / discharging of the second storage battery 16 and the third storage battery 18 by controlling the second to fourth switches SW2 to SW4 instead of the relay switch SMR. Specifically, when charging the second storage battery 16 and the third storage battery 18 in the first state, the second and third switches SW2 and SW3 are opened, and the fourth switch SW4 is closed. When the second storage battery 16 and the third storage battery 18 are discharged in the second state, the second and third switches SW2 and SW3 are closed and the fourth switch SW4 is opened. Then, when stopping the charging / discharging of the second storage battery 16 and the third storage battery 18, the second to fourth switches SW2 to SW4 are opened. This makes it possible to simplify the configuration of the power supply system 100.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to FIGS. 4 and 5, focusing on the differences from the first embodiment.

This embodiment differs from the first embodiment in that a third switch unit 24 is provided in place of the relay switch SMR. In the present embodiment, the first path LF1 and the second path LF2 provided in parallel with each other are provided between the connection point PB in the second system ES2 and the second storage battery 16 and the third storage battery 18. A third switch unit 24 is provided in the first path LF1 and the second path LF2.

The first path LF1 is provided with a fifth switching element (hereinafter, simply the fifth switch) SW5. The fifth switch SW5 opens or closes the first path LF1. In this embodiment, the fifth switch SW5 corresponds to an "open / close switch".

The second path LF2 is provided with first to third diodes DA1 to DA3 and a sixth switching element (hereinafter, simply the sixth switch) SW6 connected in series. The diodes DA1 to DA3 are arranged so that the cathode is on the connection point PB side and the anode is on the second storage battery 16 and the third storage battery 18 side, and the second storage battery 16 and the second storage battery 16 and the second diode are arranged from the connection point PB in the second path LF2. 3 Regulate the flow of current to the storage battery 18.

Further, each diode DA1 to DA3 has a predetermined forward voltage drop amount (for example, 0.7V). Therefore, the storage battery voltage VB of the connection point PC located closer to the second storage battery 16 and the third storage battery 18 than the third switch unit 24, and the power supply voltage of the converter 12 applied to the connection point PB side of the third switch unit 24. A voltage difference due to the total value of the forward voltage drops of the first to third diodes DA1 to DA3 (hereinafter, voltage difference due to the first to third diodes DA1 to DA3) is generated between the VA and the VA. The sixth switch SW6 is provided on the second storage battery 16 and the third storage battery 18 side of the first to third diodes DA1 to DA3 in the second path LF2. In this embodiment, the first to third diodes DA1 to DA3 correspond to the "discharge control unit and rectifying element".

In this embodiment, MOSFETs are used as the 5th and 6th switches SW5 and SW6. A fifth diode DA5 is connected in parallel to the fifth switch SW5 as a parasitic diode, and a sixth diode DA6 is connected in parallel to the sixth switch SW6 as a parasitic diode. In the present embodiment, the diodes DA5 and DA6 are arranged so that the cathode is on the second storage battery 16 and the third storage battery 18 side and the anode is on the connection path LB side in each path LF1 and LF2. Therefore, in the second path LF2, the first to third diodes DA1 to DA3 and the sixth diode DA6 are provided so as to be in opposite directions. Further, in the first path LF1, the fifth diode DA5 regulates the flow of current from the second storage battery 16 and the third storage battery 18 to the connection point PB, and also regulates the current flow from the connection point PB to the second storage battery 16 and the third storage battery 18. It is provided to allow the flow of current to. The third switch unit 24 is composed of the first to third diodes DA1 to DA3 and the fifth and sixth switches SW5 and SW6.

In the control process, the control device 40 generates the fifth and sixth switching signals SC5 and SC6 in order to switch the fifth and sixth switches SW5 and SW6, and commands the fifth and sixth switching signals SC5 and SC6. Is output to the 5th and 6th switches SW5 and SW6. In the control process, the control device 40 closes the fifth switch SW5 in the first state in which the second storage battery 16 and the third storage battery 18 are connected in parallel and is charged by the power supply voltage VA of the converter 12. The second storage battery 16 and the third storage battery 18 are charged via the one-path LF1. Then, when the second storage battery 16 and the third storage battery 18 are in a fully charged state, the fifth switch SW5 is opened, and the second storage battery 16 and the second storage battery 16 connected in series by the voltage difference due to the first to third diodes DA1 to DA3. 3 Regulate the discharge of the storage battery 18.

After that, when an abnormality occurs in the first system ES1, the second storage battery 16 and the third storage battery 18 are discharged via the first to third diodes DA1 to DA3. However, when the discharge of the second storage battery 16 and the third storage battery 18 via the first to third diodes DA1 to DA3 is continued, the voltage difference between the first to third diodes DA1 to DA3 applies to the second load 36. The voltage to be applied drops. Further, there is a concern that the power consumption of the second storage battery 16 and the third storage battery 18 will increase due to the voltage difference between the first to third diodes DA1 to DA3. Therefore, in the present embodiment, in the control process, the fifth switch SW5 is closed after the abnormality occurs in the first system ES1.

FIG. 5 shows a flowchart of the control process of the present embodiment. In FIG. 5, the same processing as that shown in FIG. 2 above is given the same step number for convenience, and the description thereof will be omitted.

In the control process of the present embodiment, if affirmative determination is made in step S14, the fifth switch SW5 is opened, charging of the second storage battery 16 and the third storage battery 18 is stopped in step S60, and the process proceeds to step S17. As will be described later, when the affirmative determination is made in step S14, the fifth and sixth switches SW5 and SW6 are closed.

Further, if an affirmative determination is made in step S22, that is, if it is determined that an abnormality has occurred in the first system ES1, it is determined in step S62 whether or not the first switch SW1 is open. If a negative determination is made in step S62, the first switch SW1 is opened in step S64. As a result, the discharge of the second storage battery 16 and the third storage battery 18 is started via the first to third diodes DA1 to DA3. In the following step S66, the fifth switch SW5 is closed. As a result, the second storage battery 16 and the third storage battery 18 are discharged by the first path LF1 and the second path LF2. In the following step S68, a command to put the converter 12 into the operation stop state is output, and the control process is terminated.

Further, if an affirmative determination is made in step S62, that is, if the processes of steps S64 to S68 have already been performed, the sixth switch SW6 is released in step S70, and the process proceeds to step S36. As a result, the discharge of the second storage battery 16 and the third storage battery 18 via the first to third diodes DA1 to DA3 is stopped, and the second storage battery 16 and the third storage battery 18 are discharged by the second path LF2.

On the other hand, if an affirmative determination is made in step S24, that is, if it is determined that an abnormality has occurred in the second system ES2, the first switch SW1 is released in step S32. In the following step S72, the sixth switch SW6 is released, and the process proceeds to step S36. As a result, the discharge of the second storage battery 16 and the third storage battery 18 is stopped.

Further, if an affirmative determination is made in step S44, the first switch SW1 is opened in step S52. In the following step S74, the fifth and sixth switches SW5 and SW6 are opened, and the process proceeds to step S56. On the other hand, if a negative determination is made in step S44, the second storage battery 16 and the third storage battery 18 are connected in parallel in step S45. In the following step S74, the fifth and sixth switches SW5 and SW6 are closed to end the control process.

According to the present embodiment described in detail above, the following effects can be obtained.

-In the present embodiment, the first path LF1 and the second path LF2 are provided in parallel with each other between the connection point PB in the second system ES2 and the second storage battery 16 and the third storage battery 18. In the first path LF1, the second storage battery 16 and the third storage battery 18 are charged by closing the fifth switch SW5, and the second storage battery 16 and the third storage battery 18 are charged by opening the fifth switch SW5. Is stopped. Further, the first to third diodes DA1 to DA3 are provided in the second path LF2, and the second storage battery 16 and the third storage battery are provided from the connection point PB in the second path LF2 by the first to third diodes DA1 to DA3. The flow of current to 18 is regulated.

Then, the first to third diodes DA1 to DA3 are used to cause a voltage difference between the storage battery voltage VB and the power supply voltage VA of the second storage battery 16 and the third storage battery 18 connected in series. As a result, the second storage battery 16 and the third storage battery 18 in the series state are maintained in a state where the voltage is higher than the power supply voltage VA. Then, when an abnormality occurs in the first system ES1, the second storage battery 16 and the third storage battery 18 connected in series are discharged as the storage battery voltage VB drops in the second system ES2, and the second load 36 is performed. Early power supply to is possible.

-In this embodiment, the fifth switch SW5 is opened after an abnormality occurs in the first system ES1. As a result, the load applied to the second load 36 due to the voltage difference between the first to third diodes DA1 to DA3 while enabling the early power supply to the second load 36 by the first to third diodes DA1 to DA3. It is possible to suppress a decrease in the voltage VD.

-For example, when the drive amount of the loads 34 and 36 temporarily decreases, the load voltage VD may increase excessively. When the load voltage VD rises excessively, it is desired that the overvoltage be absorbed by the second storage battery 16 and the third storage battery 18. In the present embodiment, the fifth diode DA5 connected in parallel to the fifth switch SW5 in the first path LF1 is provided. The fifth diode DA5 regulates the flow of current from the second storage battery 16 and the third storage battery 18 to the connection point PB in the first path LF1, and the current from the connection point PB to the second storage battery 16 and the third storage battery 18. It is provided to allow the flow of. Therefore, when the load voltage VD rises excessively while the fifth switch SW5 is closed, the overvoltage can be absorbed by the second storage battery 16 and the third storage battery 18 via the fifth diode DA5.

(Third Embodiment)
Hereinafter, the third embodiment will be described with reference to FIGS. 6 and 7, focusing on the differences from the second embodiment.

This embodiment is different from the configuration of the third switch unit 24 and the second embodiment. In the present embodiment, the converter 26 is provided in the first path LF1. Hereinafter, for the sake of distinction, the converter 12 is referred to as a first converter 12, and the converter 26 is referred to as a second converter 26. The second converter 26 charges the second storage battery 16 by converting the power into a voltage lower than the power supply voltage VA by supplying power from the first converter 12. In this embodiment, the second converter 26 corresponds to the "charging unit".

The second path LF2 is provided with a seventh switching element (hereinafter, simply the seventh switch) SW7. The seventh switch SW7 opens or closes the second path LF2. In this embodiment, a MOSFET is used as the seventh switch SW7. A seventh diode DA7 is connected in parallel to the seventh switch SW7 as a parasitic diode. In the present embodiment, the seventh diode DA7 is arranged so that the cathode is on the second storage battery 16 and the third storage battery 18 side and the anode is on the connection path LB side in the second path LF2. The third switch unit 24 is configured by the second converter 26 and the seventh switch SW7. In this embodiment, the seventh switch SW7 corresponds to the "discharge control unit, battery switch".

In the control process, the control device 40 generates the 7th switching signal SC7 in order to switch the 7th switch SW7, and outputs a command from the 7th switching signal SC7 to the 7th switch SW7. Further, the control device 40 generates a control signal SD in order to control the operation of the second converter 26, and outputs a command by the control signal SD to the converter 26. Hereinafter, for the sake of distinction, the control signal SD to the first converter 12 is referred to as a first control signal SD1, and the control signal SD to the second converter 26 is referred to as a second control signal SD2.

In the control process, the control device 40 opens the seventh switch SW7 in the first state in which the second storage battery 16 and the third storage battery 18 are connected in parallel and is charged by the power supply voltage VA of the converter 12. The second storage battery 16 and the third storage battery 18 connected in parallel by the two converters 26 are constantly charged with a constant current or charged with a constant voltage. Then, when the second storage battery 16 and the third storage battery 18 are in a fully charged state, charging by the second converter 26 is stopped, and the second storage battery 16 and the third storage battery 18 connected in series by the opened seventh switch SW7. Regulate discharge. After that, when an abnormality occurs in the first system ES1, the seventh switch SW7 is closed, and the second storage battery 16 and the third storage battery 18 are discharged via the second path LF2.

FIG. 7 shows a flowchart of the control process of the present embodiment. In FIG. 7, the same processing as that shown in FIG. 2 above is given the same step number for convenience, and the description thereof will be omitted.

In the control process of the present embodiment, if an affirmative determination is made in step S14, the operation of the second converter 26 is set to the stopped state in step S80, and the process proceeds to step S17. As will be described later, when the affirmative determination is made in step S14, the second converter 26 is in the operating state, and the seventh switch SW7 is open.

Further, if an affirmative determination is made in step S22, that is, if it is determined that an abnormality has occurred in the first system ES1, the first switch SW1 is released in step S26. In the following step S82, the seventh switch SW7 is closed, and the process proceeds to step S30. As a result, the second storage battery 16 and the third storage battery 18 are discharged via the seventh switch SW7.

Further, if an affirmative determination is made in step S42, the first switch SW1 is opened in step S46. In the following step S48, the second storage battery 16 and the third storage battery 18 are connected in series. In the following step S84, the operation of the first converter 12 and the second converter 26 is stopped, and the process proceeds to step S56.

Further, if an affirmative determination is made in step S44, the first switch SW1 is opened in step S52. In the following step S86, the seventh switch SW7 is released. In the following step S88, the operation of the second converter 26 is stopped, and the process proceeds to step S56. On the other hand, if a negative determination is made in step S44, the second storage battery 16 and the third storage battery 18 are connected in parallel in step S45. In the following step S89, the second converter 26 is put into an operating state, and the control process is terminated.

-According to the present embodiment described in detail above, the first path LF1 and the second path LF2 are provided in parallel with each other between the connection point PB in the second system ES2 and the second storage battery 16 and the third storage battery 18. In the first path LF1, the second converter 26 charges the second storage battery 16 and the third storage battery 18 at a voltage lower than the power supply voltage VA. Further, in the second path LF2, the discharge of the second storage battery 16 and the third storage battery 18 in the second system ES2 is regulated by the seventh switch SW7. By charging the second storage battery 16 and the third storage battery 18 with a voltage lower than the power supply voltage VA, the second converter 26 simplifies the configuration of the power supply system 100 related to the charging of the second storage battery 16 and the third storage battery 18. This makes it possible to reduce the cost burden of the power supply system 100.

(Fourth Embodiment)
Hereinafter, the fourth embodiment will be described with reference to FIG. 8, focusing on the differences from the first embodiment.

The present embodiment is different from the first embodiment in that in the control process, the second storage battery 16 and the third storage battery 18 are charged and discharged when the first and second systems ES1 and ES2 in the first mode are normal. Specifically, the control device 40 acquires the drive amount information in the loads 34 and 36, and charges and discharges the second storage battery 16 and the third storage battery 18 based on the drive amount TR indicated by the drive amount information.

In the power supply system 100, a voltage drop occurs in the second load 36 due to the occurrence of a ground fault in the first system ES1. In addition to that, it is also conceivable that an excessive voltage drop of the loads 34 and 36 may occur due to a change in the drive amount TR of the loads 34 and 36. When the voltage of the excessive loads 34 and 36 drops, it is desirable to increase the load voltage VD.

Therefore, in the present embodiment, in the control process, when the drive amount TR is switched from a state smaller than a predetermined first drive amount threshold Tth1 to a state larger than the predetermined first drive amount threshold Tth1 when the first and second systems ES1 and ES2 in the first mode are normal. In the second state, the second storage battery 16 and the third storage battery 18 are discharged while the second storage battery 16 and the third storage battery 18 are connected in series. Further, when the drive amount TR is subsequently switched from a state larger than the first drive amount threshold Tth1 to a state smaller than the first drive amount threshold value Tth1, the second storage battery 16 and the third storage battery 18 are discharged when the first and second systems ES1 and ES2 are normal. In that case, the second state is switched to the first state, and the second storage battery 16 and the third storage battery 18 are charged in a state where the second storage battery 16 and the third storage battery 18 are connected in parallel.

FIG. 8 shows a flowchart of the control process of the present embodiment. In FIG. 8, the same processing as that shown in FIG. 2 above is given the same step number for convenience, and the description thereof will be omitted.

In the control process of the present embodiment, if a negative determination is made in step S20, that is, it is determined whether or not the relay switch SMR is closed in step S90 when the first and second systems ES1 and ES2 in the first mode are normal. .. When the second storage battery 16 and the third storage battery 18 are not charged or discharged, the relay switch SMR is closed. In this case, a negative determination is made in step S90, and the process proceeds to step S22.

On the other hand, when the second storage battery 16 and the third storage battery 18 are charged and discharged, the relay switch SMR is open. In this case, an affirmative determination is made in step S90, and in step S92, the drive amount information in the loads 34 and 36 is acquired, and it is determined whether or not the drive amount TR indicated by the drive amount information is smaller than the first drive amount threshold Tth1. do. Here, the first drive amount threshold value Tth1 is a drive amount corresponding to the maximum value of electric power that can be stably supplied from the high-voltage storage battery 10 to the loads 34 and 36. The acquired drive amount information is stored in a storage unit (not shown) of the control device 40.

When the second storage battery 16 and the third storage battery 18 are in the discharged state, the drive amount TR is larger than the first drive amount threshold Tth1. In this case, a negative determination is made in step S92, and the process proceeds to step S22. On the other hand, when the second storage battery 16 and the third storage battery 18 are in the charged state, the drive amount TR is smaller than the first drive amount threshold Tth1. In this case, an affirmative determination is made in step S92, and the remaining capacity SA of the second storage battery 16 and the third storage battery 18 is calculated in step S94. In the following step S96, it is determined whether or not the remaining capacity SA calculated in step S94 is larger than the capacity threshold value Sth.

When the second storage battery 16 and the third storage battery 18 are in a fully charged state, a positive determination is made in step S96. In this case, in step S98, the relay switch SMR is released and the process proceeds to step S22. On the other hand, when the second storage battery 16 and the third storage battery 18 are not in a fully charged state, a negative determination is made in step S96. In this case, in step S100, it is determined whether or not the drive amount TR is smaller than the second drive amount threshold value Tth2. Here, the second drive amount threshold Tth2 is a threshold for switching the charging method of the second storage battery 16 and the third storage battery 18, and is set to a drive amount smaller than the first drive amount threshold Tth1. In this embodiment, the second drive amount threshold value Tth2 corresponds to a “predetermined specified value”.

If an affirmative determination is made in step S100, a charging method for simultaneously charging the second storage battery 16 and the third storage battery 18 is adopted in step S102, and the process proceeds to step S22. In the charging method of simultaneous charging, the second storage battery 16 and the third storage battery 18 are charged at the same time by closing the second and third switches SW2 and SW3 at the same time with the fourth switch SW4 open.

On the other hand, if a negative determination is made in step S100, a charging method for individually charging the second storage battery 16 and the third storage battery 18 is adopted in step S104, and the process proceeds to step S22. In the charging method for individually charging, the second storage battery 16 and the third storage battery 18 are individually charged by alternately closing the second and third switches SW2 and SW3 with the fourth switch SW4 open.

Further, if an affirmative determination is made in step S22, that is, if it is determined that an abnormality has occurred in the first system ES1, the first switch SW1 is released in step S26. In the following step S116, the second storage battery 16 and the third storage battery 18 are switched to the series connection, and the process proceeds to step S28. Further, if an affirmative determination is made in step S24, that is, if it is determined that an abnormality has occurred in the second system ES2, the first switch SW1 is opened in step S32. In the following step S118, the relay switch SMR is released and the process proceeds to step S36.

Further, if a negative determination is made in step S24, it is determined in step S110 whether or not the drive amount TR is larger than the first drive amount threshold Tth1. The drive amount TR acquired in the previous control process is smaller than the first drive amount threshold Tth1, and the drive amount TR is smaller than the first drive amount threshold Tth1 in the current control process to be smaller than the first drive amount threshold Tth1. When the state is switched to the larger state, an affirmative determination is made in step S110. In this case, in step S112, the second storage battery 16 and the third storage battery 18 are switched to the series connection. In the following step S114, the relay switch SMR is closed and the control process is terminated. As a result, the second storage battery 16 and the third storage battery 18 are discharged in the second state in which the second storage battery 16 and the third storage battery 18 are connected in series.

On the other hand, if a negative determination is made in step S110, it is determined in step S116 whether or not the drive amount TR is smaller than the first drive amount threshold Tth1. The drive amount TR acquired in the previous control process is larger than the first drive amount threshold Tth1, and the drive amount TR is larger than the first drive amount threshold Tth1 in the current control process to be larger than the first drive amount threshold Tth1. When the state is switched to the smaller state, an affirmative determination is made in step S116. In this case, in step S118, the second storage battery 16 and the third storage battery 18 are switched to parallel connection, and the control process is terminated. As a result, in a state where the second storage battery 16 and the third storage battery 18 are connected in parallel, the first state is set in which the converter 12 is charged by the power supply voltage VA. That is, the second storage battery 16 and the third storage battery 18 are switched from the second state to the first state.

On the other hand, if the drive amount TR acquired in the previous and current control processes is both larger than the first drive amount threshold Tth1 or both are smaller than the first drive amount threshold Tth1, a negative determination is made in step S116. In this case, the control process is terminated.

According to the present embodiment described in detail above, the following effects can be obtained.

-In this embodiment, the second state is set when the drive amount TR of the loads 34 and 36 is switched from a state smaller than the first drive amount threshold Tth1 to a state larger than the first drive amount threshold Tth1. Therefore, even if the drive amount TR of the loads 34 and 36 temporarily increases in the normal state of the first and second systems ES1 and ES2, the power from the second storage battery 16 and the third storage battery 18 connected in series Supply is done. As a result, power can be supplied to the loads 34 and 36 at a voltage higher than the power supply voltage VA, and the loads 34 and 36 can be operated properly.

In the present embodiment, when the first and second systems ES1 and ES2 are in the second state in the normal state, the drive amount TR of the loads 34 and 36 is from a state larger than the first drive amount threshold Tth1 to a smaller state. When switched to, the second state is switched to the first state, and the second storage battery 16 and the third storage battery 18 are charged. Therefore, even if the second storage battery 16 and the third storage battery 18 are temporarily discharged in the normal state of the first and second systems ES1 and ES2, the second storage battery 16 and the third storage battery 18 are subsequently fully charged. be able to. Therefore, it is possible to continue driving the second load 36 by using the second storage battery 16 and the third storage battery 18 that are fully charged when an abnormality occurs in the first system ES1.

-In the first state, the power supply to the loads 34 and 36 and the power supply to the second storage battery 16 and the third storage battery 18 are performed at the same time, so it is necessary to properly supply these powers. In this respect, in the present embodiment, when the drive amount TR of the loads 34 and 36 is smaller than the second drive amount threshold Tth2, the second storage battery 16 and the third storage battery 18 are charged at the same time, and the drive amount TR is the second drive. When the amount threshold value is larger than Tth2, the second storage battery 16 and the third storage battery 18 are individually charged. By adjusting the number of storage batteries charged by the drive amount TR, the load related to the power supply of the converter 12 is adjusted, and the power supply to the loads 34 and 36 and the power supply to the second storage battery 16 and the third storage battery 18 are performed. Can be properly implemented.

(Other embodiments)
The present disclosure is not limited to the description of the above embodiment, and may be implemented as follows.

-Each load 34, 36 may be, for example, the following device.

It may be a traveling motor that imparts driving power to the vehicle and its drive circuit. In this case, each of the first and second loads 34 and 36 is, for example, a three-phase permanent magnet synchronous motor and a three-phase inverter device.

It may be an anti-lock braking device that prevents the wheels from locking during braking. In this case, each of the first and second loads 34 and 36 is, for example, an ABS actuator that can independently adjust the brake hydraulic pressure during braking.

The vehicle in front of the vehicle is detected, and if the vehicle in front is detected, the distance between the vehicle and the vehicle in front is kept constant. If the vehicle in front is not detected, the vehicle is in front of the vehicle. It may be a cruise control device for traveling at a preset vehicle speed. In this case, each of the first and second loads 34 and 36 is, for example, a millimeter wave radar.

-The loads 34 and 36 do not necessarily have to be a combination having the same configuration, and may be a combination that realizes the same function with devices of different types. Further, the first and second loads 34 and 36 may not be different loads but may be the same load. That is, the first and second loads 34 and 36 may be the same load that receives power from both the first in-system path LA1 and the second in-system path LA2.

-The first power supply is not limited to the converter, but may be an alternator. Further, the first power supply may not have a converter, and may have, for example, only the first storage battery 14.

-The plurality of storage batteries included in the second power source are not limited to two, and may be three or more. In this case, when connecting a plurality of storage batteries in series in the second state, the number of storage batteries connected in series may be switched based on the driving amount of the electric load.

-In the second state, the voltage applied to the electric load from the plurality of storage batteries is not limited to a voltage higher than the power supply voltage of the first power supply. For example, when the required voltage of the electric load is determined based on the driving amount of the electric load, the voltage may be set higher than this required voltage.

-The rectifying element provided in the second path LF2 is not limited to the diode, but may be a thyristor.

-In the above first embodiment, an example in which the opening of the first switch SW1 and the closing of the relay switch SMR are performed at the same time is shown, but the present invention is not limited to this. For example, the relay switch SMR may be closed after the first switch SW1 is opened. As a result, it is possible to suppress the discharge of the second storage battery 16 and the third storage battery 18 to the first system ES1 when an abnormality occurs in the first system ES1. Further, the first switch SW1 may be opened after the relay switch SMR is closed. As a result, it is possible to suppress a decrease in the load voltage VD due to the occurrence of an abnormality in the first system ES1.

-In the first embodiment, the charging of the second storage battery 16 and the third storage battery 18 may be controlled by the relay switch SMR. Specifically, when the second storage battery 16 and the third storage battery 18 are charged in the first state, the charging of the second storage battery 16 and the third storage battery 18 is controlled by controlling the duty ratio of the relay switch SMR. You may. Here, the duty ratio means the ratio of the closing time of the relay switch SMR to the specified period of the relay switch SMR controlled to be opened and closed. Further, a resistance element is provided between the relay switch SMR in the path LA2 in the second system and the second storage battery 16 and the third storage battery 18, and the resistance element charges and discharges the second storage battery 16 and the third storage battery 18. May be controlled.

-In the above embodiment, an example is shown in which the power supply system 100 is applied to a vehicle capable of traveling by manual driving and automatic driving, but the present invention is not limited to this. It may be applied to a vehicle that can only be driven by automatic driving, such as a fully autonomous vehicle, or may be applied to a vehicle that can only be driven by manual driving.

For example, when applied to a vehicle capable of traveling only by automatic driving, when an abnormality occurs in one of the systems ES1 and ES2, the loads 34 and 36 of the other system ES1 and ES2 in which the abnormality has not occurred are applied. It may be used to stop the running of the vehicle by automatic driving, or to stop the vehicle after moving it to a safe place.

Although the present disclosure has been described in accordance with the examples, it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various variations and variations within a uniform range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are within the scope and scope of the present disclosure.

Claims (11)

1. Electric load (34, 36) and
   The first system (ES1) including the first power supply (10, 12) connected to the electric load, and
   A second system (ES2) including a second power source (16, 18) connected to the electrical load, and
   A power supply system (100) having an inter-system switch (SW1) provided in a connection path (LB) that connects the first system and the second system to each other.
   The first power supply outputs a power supply voltage that enables driving of the electric load.
   The second power source includes a plurality of storage batteries (16, 18) that can be charged by the power source voltage of the first power source.
   An abnormality determination unit that determines that an abnormality has occurred in the first system,
   A state control unit that opens the inter-system switch when it is determined by the abnormality determination unit that an abnormality has occurred.
   When charging the plurality of storage batteries, a first control unit in which the plurality of storage batteries are connected in parallel and power is supplied from the first power source to the plurality of storage batteries is set as a first state.
   When discharging the plurality of storage batteries, the plurality of storage batteries are connected in series, and the electricity is supplied from the plurality of storage batteries at a voltage higher than the power supply voltage of the first power supply or a voltage higher than the required voltage of the electric load. A power supply system including a second control unit that is in a second state of supplying power to a load.
2. Discharge control units (SMR, DA1 to DA3, SW7) provided between the connection point (PB) with the connection path in the second system and the second power source to regulate the discharge of the plurality of storage batteries in a series state. The power supply system according to claim 1.
3. In the first state, it is determined that the total voltage of the plurality of storage batteries is in a fully charged state, which is a voltage higher than the power supply voltage of the first power supply or a voltage higher than the required voltage of the electric load. Equipped with a charge judgment unit,
   The power supply system according to claim 2, wherein the discharge control unit regulates the discharge of the plurality of storage batteries in a series state when the charge determination unit determines that the fully charged state is reached.
4. The discharge control unit includes a battery switch (SMR, SW7) that opens or closes a path between a connection point (PB) with the connection path and the second power supply in the second system.
   The state control unit
   When it is determined by the abnormality determination unit that no abnormality has occurred, the inter-system switch is closed and the battery switch is opened to regulate the discharge of the plurality of storage batteries.
   The second or third aspect of the present invention, wherein when the abnormality determination unit determines that an abnormality has occurred, the inter-system switch is opened and the battery switch is closed to release the discharge restriction of the plurality of storage batteries. Power system.
5. It is a power supply system installed in a vehicle.
   The electric load is a load that performs at least one function necessary for driving in the vehicle, and is a load that performs a driving support function of the vehicle.
   The vehicle can travel in the first mode using the driving support function and in the second mode not using the driving support function.
   The first control unit is set to the first state in the second mode.
   The power supply system according to any one of claims 2 to 4, wherein the state control unit permits switching to the first mode when the discharge of the plurality of storage batteries is restricted by the discharge control unit. ..
6. The first path (LF1) and the second path (LF2) provided in parallel between the connection point (PB) with the connection path and the second power supply in the second system,
   A charging unit (26) provided in the first path and charging the plurality of storage batteries connected in parallel to a voltage lower than the power supply voltage of the first power supply by supplying power from the first power supply is provided. ,
   The power supply system according to any one of claims 2 to 5, wherein the discharge control unit is provided in the second path and regulates discharge of the plurality of storage batteries in the second system.
7. The first path (LF1) and the second path (LF2) provided in parallel between the connection point (PB) with the connection path and the second power supply in the second system,
   An open / close switch (SW5) provided in the first path and which opens or closes the first path is provided.
   The discharge regulating unit is provided in the second path, regulates the flow of current from the connection point to the plurality of storage batteries in the second path, and regulates the voltage of the plurality of storage batteries connected in series and the power source. The power supply system according to any one of claims 2 to 5, further comprising a rectifying element (DA1 to DA3) that causes a predetermined voltage difference from the voltage.
8. The first control unit acquires the drive amount information indicating the drive amount of the electric load, and obtains the drive amount information.
   The second control unit corresponds to any one of claims 1 to 6 in which the second control unit is set to the second state when the drive amount indicated by the drive amount information is switched from a state smaller than a predetermined threshold value to a state larger than the predetermined threshold value. The power supply system described.
9. The first control unit is the second state when the drive amount indicated by the drive amount information is switched from a state smaller than the threshold value to a state larger than the threshold value and then from a state larger than the threshold value to a state smaller than the threshold value. The power supply system according to claim 8, wherein the first state is switched to and the plurality of storage batteries are charged.
10. The first control unit is
    The drive amount information indicating the drive amount of the electric load is acquired, and the drive amount information is acquired.
    When the drive amount indicated by the drive amount information is smaller than a predetermined specified value, the plurality of storage batteries are connected in parallel to charge the plurality of storage batteries at the same time.
    According to any one of claims 1 to 9, when the drive amount indicated by the drive amount information is larger than the specified value, the plurality of storage batteries are connected in parallel and the plurality of storage batteries are individually charged. The power supply system described.
11. The plurality of storage batteries include a first specific battery (16) and a second specific battery (18) provided between a predetermined first potential point (PC) and a second potential point (PD).
    The positive electrode terminal of the first specific battery is connected to the first potential point by the first positive electrode side path (LC1) and is connected to the second potential point by the first negative electrode side path (LD1).
    The positive electrode terminal of the second specified battery is connected to the first potential point by the second positive electrode side path (LC2) and is connected to the second potential point by the second negative electrode side path (LD2).
    The first changeover switch (SW2) provided in the first negative electrode side path and
    The second changeover switch (SW3) provided in the second positive electrode side path and
    Of the first negative electrode side path, the first connection point (PE) on the first specific battery side of the first changeover switch, and the second potential of the second positive electrode side path of the second changeover switch. A third changeover switch (SW4) provided in the conduction path (LE) between the second connection point (PF) on the point side is provided.
    In the first state, the first control unit closes the first changeover switch and the second changeover switch, and opens the third changeover switch.
    In the second state, the second control unit opens the first changeover switch and the second changeover switch, and closes the third changeover switch.
    In the first control unit and the second control unit, at the time of switching between the first state and the second state, at least one of the first changeover switch and the second changeover switch and the third changeover switch are used. The power supply system according to any one of claims 1 to 10, which controls the opening and closing of each changeover switch so as not to be closed at the same time.

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