JP7069765B2 - Power system - Google Patents

Description

The present invention relates to a power supply system that supplies power to a load.

As a power supply system, a system is known in which a plurality of batteries (for example, a lead battery and a lithium ion battery) are used, and power is supplied to a load while using each of these batteries properly.

In Patent Document 1, a load (electric load 43) is connected to an electric path connecting a lead battery and a lithium ion battery. Among the electric paths, the first switch (switch 53) is provided in the path connecting the lead battery and the load, and the second switch (switch 54) is provided in the path connecting the lithium ion battery and the load. In such a configuration, if one of the first switch and the second switch is turned on, power can be supplied to the load from either the lead battery or the lithium ion battery.

However, when power is supplied from one of the batteries to the load, if both the first switch and the second switch are turned off due to an open failure or the like, the power cannot be supplied to the load. Therefore, in Patent Document 1, a bypass switch (first bypass switch 55 and second) is used as a bypass path (first bypass path B1 and second bypass path B2) that bypasses the first switch and connects the lead battery and the load. A bypass switch 56) is provided.

Then, the bypass switch is switched on on condition that both the first switch and the second switch are off. As a result, even if the power supply path to the load cannot be secured via the first switch and the second switch, the power supply path from the lead battery to the load is secured via the bypass path.

Japanese Unexamined Patent Publication No. 2015-149849

However, it is inevitable that the power supply to the load will be interrupted from the time when both the first switch and the second switch are turned off and the power supply path to the load cannot be secured until the bypass switch is switched on. There is a problem such as.

The present invention has been made in view of the above, and an object of the present invention is to provide a power supply system capable of avoiding interruption of power supply from a power source to a load.

In the first means, a load (R11) connected to an electric path (L1) connecting the first power supply (11) and the second power supply (12), and
Among the electric paths, a first switch (SW1) provided in the first path (L11) connecting the first power supply and the load, and
Of the electric paths, a second switch (SW2) provided in the second path (L12) connecting the second power supply and the load, and
A diode portion (D) composed of at least one diode, the first diode portion (D1) connected in parallel to the first switch so that a forward current flows from the first power supply to the load. And the second diode section (D2) connected in parallel to the second switch so that a forward current flows from the second power supply to the load.
A current detection unit (102) that detects the current flowing through the first diode unit and the second diode unit, and the current detection unit (102).
A switch control unit (101) that controls so that one of the first switch and the second switch is on and the other is off is provided.
The switch control unit
The first switch is turned on and the second switch is turned off on condition that the current flowing through the first diode portion is equal to or higher than a predetermined value.
The first switch is turned off and the second switch is turned on on condition that the current flowing through the second diode portion is equal to or higher than a predetermined value.

Connect the load to the electrical path connecting the first and second power supplies. Then, among the electric paths, a first switch is provided in the first path connecting the first power supply and the load, and a second switch is provided in the second path connecting the second power supply and the load. In such a configuration, if one of the first switch and the second switch is turned on, power can be supplied from one of the first power supply and the second power supply to the load.

However, if one switch is turned off and the other switch is turned on at the same time, both switches are turned off momentarily, and the power supply to the load may be interrupted.

Therefore, the first diode section is connected in parallel to the first switch so that the forward current flows from the first power supply to the load. Similarly, the second diode section is connected in parallel to the second switch so that the forward current flows from the second power supply to the load. Each diode portion is configured by using at least one diode.

Then, the states of both switches are switched on the condition that a current of a predetermined value or more is flowing in one of the diode portions and a power supply path to the load is secured through the diode portion.

Specifically, when the first switch is off and the second switch is on, power is supplied from the second power supply to the load, and the voltage of the second power supply gradually decreases. On the other hand, since the power is not supplied from the first power supply to the load, the voltage of the first power supply does not decrease. Therefore, when the voltage of the second power supply drops, the potential difference between the first power supply and the second power supply increases. When the potential difference between the first power supply and the second power supply becomes a magnitude corresponding to the forward voltage of the first diode portion, the first diode portion is conducted and the forward current flows. That is, a feeding path from the first power source to the load is secured via the first diode portion.

Then, in the situation where the power supply path to the load is secured through the first diode portion in this way, if the first switch is turned on and the second switch is turned off, both switches are instantaneous. Even if it is turned off, it is possible to prevent the power supply to the load from being interrupted.

Similarly, when the current flowing through the second diode section is equal to or greater than the specified value and the power supply path to the load is secured via the second diode section, the first switch should be turned off and the second switch should be turned on. By setting this, even if both switches are turned off momentarily, it is possible to prevent the power supply to the load from being interrupted.

Further, regarding the diode, when the current flowing through the diode exceeds a predetermined value, the switch is switched on, so that the current of the predetermined value or more does not continuously flow through the diode. This protects the diode.

In the second means, the diode portion is configured by connecting a plurality of the diodes in series so that the forward current flows when the potential difference between the first power supply and the second power supply becomes a predetermined value or more. Will be done.

The diode has a characteristic that when the temperature rises, the forward voltage required for the diode to conduct and the forward current flows decreases. Therefore, when the temperature of the diode becomes high, the diode is conducted even if the potential difference between the first power supply and the second power supply is smaller than the desired size. Therefore, the period from the previous conduction of the diode to the next conduction is shortened. Further, since the diode is conducted again before the temperature of the diode is sufficiently lowered, the temperature of the diode rises, which may cause a failure of the diode. Further, regarding the switch, the on / off state is frequently switched, which is disadvantageous in terms of maintaining durability.

Therefore, the diode section is configured by connecting a plurality of diodes in series. As a result, the forward voltage required for the forward current to flow in the diode portion can be increased as compared with the case where the diode portion is composed of a single diode.

The fact that the voltage required for the diode portion to conduct becomes large means that the potential difference between the first power supply and the second power supply required for the diode portion to conduct becomes large. Then, in order to increase the potential difference between the first power supply and the second power supply, it is necessary that the voltage of the power supply that is supplying power to the load is further lowered.

In this case, it takes time for the diode portion to conduct conduction, and it becomes easy to secure the time until the diode portion is cooled by heat dissipation. As a result, the temperature rise of the diode portion can be suppressed. Further, regarding the switch, since the period until the on / off state is switched is long, it is advantageous in terms of maintaining the durability.

In order to lower the temperature of the diode portion, it is conceivable to provide a heat radiating member for the diode portion, but in order to provide the radiating member, it is necessary to increase the cost and increase the size of the device. On the other hand, in the above configuration, the heat dissipation function of the diode portion can be enhanced only by increasing the number of inexpensive diodes, which is advantageous in terms of cost and the like when configuring the device.

In the third means, when the switch control unit switches the on / off state of the first switch and the second switch, the switch in the on state is switched off and then the switch in the off state is switched on. ..

When switching the on / off state of the first switch and the second switch, if one switch is turned off and the other switch is turned on at the same time, both switches are momentarily turned on and a through current flows, which is the first. It may be a burden on the switch and the second switch. Therefore, as the order of switching the on / off state of both switches, the switch in the on state is switched off first, and then the switch in the off state is switched on. This prevented both switches from being on at the same time.

For example, when the first switch is on and the second switch is off, the current flowing through the second diode exceeds a predetermined value, and when it is time to switch the switch state, the first switch is turned off first. After switching to, switch the second switch to on. By switching the switch states in this order, the influence of the through current can be avoided.

If the switch states are switched in the above order, there will be a moment when both the first switch and the second switch are turned off. However, even if both switches are turned off, the power supply path from the power supply to the load is secured through the diode section during that time. Therefore, the on / off state of each switch can be switched while avoiding interruption of power supply to the load.

In the fourth means, the first bypass switch (BSW1) provided in the path bypassing the first switch and switching the electrical connection state between the first power supply and the load and the second switch are bypassed. A bypass switch including at least one of a second bypass switch (BSW2) provided in the path and switching an electrical connection state between the second power supply and the load.
When the first bypass switch is provided, power cannot be supplied from the first power supply to the load via the first path, provided that the first switch is on. When it is determined that an abnormality has occurred and the second bypass switch is provided, the second power supply can be used from the second power source via the second path, provided that the second switch is on. It is equipped with an abnormality determination unit (103) for determining that a power supply abnormality has occurred in which power cannot be supplied to the load.
The control unit controls so that one of the first switch and the first bypass switch is on and the other is off, one of the second switch and the second bypass switch is on, and the other is off. There,
The switch control unit
When the first bypass switch is provided, the state of the first switch is on the condition that the first switch is on and the power supply abnormality has occurred via the first path. Regardless of, the first bypass switch is turned on,
When the second bypass switch is provided, the second switch is turned on and it is determined that the power supply abnormality has occurred via the second path. The second bypass switch is turned on regardless of the state of the two switches.

If at least one of the first switch and the second switch has an abnormality due to an open failure, etc., the switch cannot be turned on correctly even if the switch is controlled to be turned on (the switch does not turn on correctly). It remains off), and power cannot be supplied from the power supply to the load via the switch. In this case, since the current flows through the diode connected in parallel to the switch in which the abnormality occurs, it is possible to secure the feeding path to the load. However, the continuous flow of current through a diode, which is less durable than a switch, causes a diode failure.

Therefore, a bypass switch for switching the electrical connection state between each power supply and the load is provided in the path bypassing each switch. Specifically, as a bypass switch, it is provided in a path that bypasses the first switch, a first bypass switch that switches the electrical connection state between the first power supply and the load, and a path that bypasses the second switch. , At least one of a second bypass switch for switching the electrical connection state between the second power supply and the load is provided.

With such a configuration, even if a power supply abnormality occurs in which power cannot be supplied from the power supply to the load via the first switch or the second switch, the bypass switch connected in parallel to the switch can be switched on. If so, the load can be supplied via the bypass switch. Therefore, it is possible to continue supplying power to the load while protecting the diode.

Specifically, when the first switch is off and the second switch is on, the first switch is turned on and the second switch is turned on, provided that a current equal to or higher than a predetermined value is flowing through the first diode section. Control to switch off is performed. At this time, if the first switch is open and faulty, the first switch remains off, so that the current to the load continues to flow through the first diode section, which is the cause of the first diode section. It may cause a malfunction. On the other hand, if such a power supply abnormality occurs, if the first bypass switch is switched on, the load is supplied to the load via the first diode section, and then the load is supplied via the first bypass switch. It is possible to switch to the state where power is supplied to. As described above, even if the switch fails, it is possible to continuously supply power to the load while protecting the diode portion.

In the fifth means, an open / close switch (SW1) provided in the electric path (L1) connecting the power supply (11) and the load (R11) is used.
A bypass switch (BSW1) provided in a path that bypasses the open / close switch and switches the electrical connection state between the power supply and the load.
A diode section (D) configured using at least one diode and connected in parallel to at least one of the open / close switch and the bypass switch so that a forward current flows from the power supply to the load.
A switch control unit (101) that controls so that one of the open / close switch and the bypass switch is on and the other is off.
An abnormality determination unit (103) for determining that a power supply abnormality in which power cannot be supplied from the power supply to the load via the electric path occurs when the open / close switch is turned on is provided.
When it is determined that the power supply abnormality has occurred, the switch control unit turns on the bypass switch regardless of the state of the open / close switch.

An open / close switch is provided in the electric path connecting the power supply and the load, and a bypass switch for switching the electrical connection state between the power supply and the load is provided in the path bypassing the open / close switch. In such a configuration, even if an abnormality such as an open failure occurs in the open / close switch and a power supply abnormality occurs in which power cannot be supplied from the power supply to the load via the electric path, the bypass switch can be turned on by turning on the bypass switch. It is possible to continue power supply from the power supply to the load via the path provided with.

However, the power supply from the power supply to the load is interrupted between the time when the power supply abnormality is determined and the time when the bypass switch is switched on.

Therefore, a diode was connected in parallel to at least one of the open / close switch and the bypass switch so that the forward current flows from the power supply to the load. With such a configuration, it is possible to secure a power supply path from the power supply to the load via the diode even from the time when it is determined that the power supply abnormality has occurred until the bypass switch is switched on. ..

In the sixth means, the open / close switch is a first open / close switch (SW1) provided in the first electric path (L11) connecting the first power supply (11) and the load (R11), and the second power supply (SW1). A second open / close switch (SW2) provided in the second electric path (L12) connecting the 12) and the load, and
A bypass switch (BSW1) provided in a path that bypasses the first open / close switch and switches the electrical connection state between the first power supply and the load.
A diode portion (D) connected in parallel to at least one of the first open / close switch and the bypass switch so that a forward current flows from the first power supply to the load.
A first switch control unit (101) that controls so that one of the first open / close switch and the second open / close switch is on and the other is off.
A second switch control unit (101) that turns on the bypass switch, provided that both the first open / close switch and the second open / close switch are off.
To prepare for.

When the first open / close switch is provided in the first electric path connecting the first power supply and the load and the second open / close switch is provided in the second electric path connecting the second power supply and the load, the first open / close switch is provided. If one of the switch and the second open / close switch is controlled to be on and the other is off, the load can be supplied from either the first power supply or the second power supply.

However, in such a configuration, if both open / close switches are turned off, the power supply to the load is interrupted.

Therefore, a bypass switch for switching the electrical connection state between the first power supply and the load is provided in the path bypassing the first open / close switch. Then, the bypass switch is switched on on condition that both the first open / close switch and the second open / close switch are off.

With such a configuration, even if both the first open / close switch and the second open / close switch are turned off, the power supply path from the first power supply to the load can be secured via the bypass switch.

In the seventh means, the load is an in-vehicle device (EL1) whose state is reset when the applied voltage fluctuates beyond a predetermined range.

When the load is an in-vehicle device whose state is reset when the applied voltage fluctuates beyond a predetermined range, the above configuration is applied to stably supply power to the in-vehicle device. Therefore, it is possible to suppress the occurrence of inconveniences such as unnecessary resets.

In the eighth means, a first open / close switch (SW1) provided in the first electric path (L1) connecting the power supply (11) and the first load (R11) is used.
A second open / close switch (SW3) provided in the second electric path (L21) connecting the power supply and the second load (30), and
A first bypass switch (BSW1) provided in a path that bypasses the first open / close switch and switches an electrical connection state between the power supply and the first load.
A second bypass switch (BSW2) provided in a path that bypasses the second open / close switch and switches the electrical connection state between the power supply and the second load.
A first diode section (D1) connected in parallel to at least one of the first open / close switch and the first bypass switch so that a forward current flows from the power supply to the first load.
A second diode portion (D2) connected in parallel to at least one of the second open / close switch and the second bypass switch so that a forward current flows from the power supply to the second load.
A switch control unit (101) for switching on and off of the first open / close switch and the second open / close switch,
Even if the first open / close switch is switched on by the switch control unit, power cannot be supplied to the first load, or even if the second open / close switch is switched on by the switch control unit. It is provided with an abnormality determination unit (103) for determining that a power supply abnormality has occurred when power supply to the second load cannot be performed.
When it is determined that the power supply abnormality has occurred, the switch control unit is provided in a path that bypasses the open / close switch regardless of the state of the open / close switch in the path in which the power supply abnormality is determined. A power supply system characterized in that the bypass switch is turned on.

A first open / close switch is provided in the first electric path connecting the power supply and the first load, and a second open / close switch is provided in the second electric path connecting the power supply and the second load. Further, a first bypass switch is provided on the path bypassing the first open / close switch, and a second bypass switch is provided on the path bypassing the second open / close switch. With such a configuration, even if an abnormality such as an open failure occurs in one of the open / close switches, if the bypass switch connected in parallel to the open / close switch is turned on, each load (first load) from the power supply is turned on. , The second load) can be continued to be supplied.

However, in each electric path (first electric path or second electric path), between the time when the power supply abnormality is determined and the time when the bypass switch (first bypass switch, second bypass switch) is switched on, The power supply from the power supply to the load (first load, second load) is interrupted.

Therefore, a diode is connected in parallel to at least one of each open / close switch and each bypass switch so that a forward current flows from the power supply to each load.

With such a configuration, even in a configuration in which a first load and a second load are provided as loads, a power supply is supplied even after it is determined that a power supply abnormality has occurred until the bypass switch is switched on. It is possible to secure a power supply path from to each load.

In the ninth means, a first open / close switch (SW1) provided in the first electric path (L1) connecting the power supply (11) and the first load (R11) is used.
A second open / close switch (SW3) provided in the second electric path (L21) connecting the power supply and the second load, and
A first bypass switch (BSW1) provided in a path that bypasses the first open / close switch and switches an electrical connection state between the power supply and the first load.
A second bypass switch (BSW2) provided in a path that bypasses the second open / close switch and switches the electrical connection state between the power supply and the second load.
A first diode (D1) connected in parallel to at least one of the first open / close switch and the first bypass switch so that a forward current flows from the power supply to the first load.
A second diode (D2) connected in parallel to at least one of the second open / close switch and the second bypass switch so that a forward current flows from the power supply to the second load.
A first switch control unit (101) for switching on and off of the first open / close switch and the second open / close switch,
The first bypass switch is switched on on condition that the first open / close switch remains off even if the first open / close switch is switched on by the first switch control unit, and the first switch is switched on. With the second switch control unit (101) that switches the second bypass switch on, provided that the second open / close switch remains off even if the second open / close switch is switched on by the control unit. ,
A power supply system characterized by being equipped.

In a configuration in which a first open / close switch is provided in the first electric path connecting the power supply and the first load, and a second open / close switch is provided in the second electric path connecting the power supply and the second load, the first open / close switch or the first open / close switch is provided. 2 When the open / close switch is turned off, the power supply from the power supply to each load is interrupted. Therefore, a first bypass switch for switching the electrical connection state between the power supply and the first load is provided in the path bypassing the first open / close switch. Further, a second bypass switch for switching the electrical connection state between the power supply and the second load is provided in the path bypassing the second open / close switch. Then, the first bypass switch is switched on on condition that the first open / close switch is off, and the second bypass switch is switched on on condition that the second open / close switch is off. .. By performing such a process, even if the first open / close switch or the second open / close switch is turned off, a power supply path to each load can be secured via each bypass switch.

Further, since the first diode is connected in parallel to at least one of the first open / close switch and the first bypass switch, and the second diode is connected in parallel to at least one of the second open / close switch and the second bypass switch, each open / close switch is turned off. It is possible to secure a power supply path from the power supply to each load even from the time when the presence is detected until each open / close switch is switched on. As described above, it is possible to continuously secure a power supply path to each load.

In the tenth means, the first load is an in-vehicle device (EL1) that needs to be applied with a voltage in a predetermined range.
The second load is a rotary electric machine (30) having a power generation function of generating power by the power of an engine and an electric function of being rotated by power supply from the power source.

In the case of a rotary electric machine having a power generation function of generating power by the power of an engine and an electric function of being rotated by power supply from a power source, the above configuration is applied to stabilize the load with respect to the rotary electric machine. Since power is supplied to the rotary electric machine, the operation of the rotary electric machine can be stabilized.

The figure which shows the schematic structure of 1st Embodiment of a power-source system. The figure which shows the execution example of the operation of 1st Embodiment of a power-source system. The figure which shows the schematic structure of the 2nd Embodiment of a power-source system. The figure which shows the schematic structure of the 3rd Embodiment of a power-source system. The figure which shows the processing procedure of 3rd Embodiment of a power-source system. The figure which shows the execution example of the operation of the 3rd Embodiment of a power-source system. The figure which shows the execution example of the operation of the 3rd Embodiment of a power-source system. The figure which shows the schematic structure of 4th Embodiment of a power-source system.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. Each of the following embodiments shows a power supply system mounted on a vehicle and supplying electric power to various in-vehicle devices (loads). Further, in each embodiment, the same or equal parts are designated by the same reference numerals in the drawings, and the description thereof is used for the parts having the same reference numerals.

(First Embodiment)
As shown in FIG. 1, the power supply system includes a lead battery 11, a lithium ion battery 12, a starter 13, a load R11, a load R12, a rotary electric machine 30, switches SW1 to SW4, a diode unit D, current sensors I1 and I2, and a control device. It has 100.

The lead battery 11 is a well-known general-purpose battery. On the other hand, the lithium ion battery 12 is a high-density battery having a smaller power loss in charging / discharging and a higher output density and energy density than the lead battery 11. Therefore, it can be said that the lithium ion battery 12 has a characteristic that the charge / discharge efficiency is higher than that of the lead battery 11 and a characteristic that the durability against repeated charging / discharging is high.

Further, the lithium ion battery 12 has a characteristic that the voltage fluctuation range with respect to the fluctuation of the state of charge (SOC) is large and the internal resistance is small as compared with the lead battery 11. Further, the lithium ion battery 12 has excellent cycle characteristics as compared with the lead battery 11, and has characteristics that deterioration due to charging / discharging is relatively mild. The SOC refers to the ratio of the actual charge amount to the charge amount at the time of full charge.

The lead battery 11 and the lithium ion battery 12 are electrically connected in parallel to the rotary electric machine 30. The rotary electric machine 30 is a generator with a motor function having a three-phase AC motor and a motor control unit that controls the drive of the motor. For example, as shown in FIG. 1, as an ISG (Integrated Starter Generator) integrated with mechanical and electrical equipment. It is composed. The rotary electric machine 30 has a power generation function of generating power (regenerative power generation) by rotating an engine output shaft or an axle, and a power running function of applying a rotational force to the engine output shaft.

While the vehicle is running, power is generated by the power generation function of the rotary electric machine 30, and the generated power is supplied to the batteries 11, 12, and the like. On the other hand, when the engine ENG, which is automatically stopped by idling stop control, is restarted when the vehicle is stopped, the power running function of the rotary electric machine 30 supplies power from the batteries 11 and 12 to the engine output shaft and the like. Is rotated and the engine ENG is restarted. The batteries 11 and 12 are provided with a voltage sensor, a current sensor and a temperature sensor (not shown), and the SOC is calculated based on the detection results of each of these sensors. When both batteries 11 and 12 are charged by the generated power of the rotary electric machine 30 or when the rotary electric machine 30 is driven by the power supply from either of the batteries 11 and 12, this SOC is set within a predetermined range. Is adjusted to.

The load R12 is composed of an in-vehicle device EL2 in which fluctuations in the input voltage are relatively tolerated among various in-vehicle devices. For example, the in-vehicle device EL2 is a seat heater, a heater for a defroster of a rear window, a headlight, a wiper of a front window, a blower fan of an air conditioner, and the like. The load R12 is composed of at least one of these in-vehicle devices EL2.

The load R11 is composed of an in-vehicle device EL1 having a relatively narrow allowable range of input voltage fluctuation among various in-vehicle devices. For example, the in-vehicle device EL1 is a navigation device, an audio device, a meter device, various ECUs such as an engine ECU, a traveling system actuator such as an electric steering device and a braking device, and the like. The load R11 is composed of at least one of these in-vehicle devices EL1.

It is required that a voltage within a predetermined range is applied to the in-vehicle device EL1 in order to suppress the occurrence of an unnecessary reset or the like, that is, the voltage fluctuation of the supplied power is suppressed. Therefore, the load R11 can be said to be a constant voltage required load.

Each of these members constituting the power supply system is electrically connected to each other by using the battery unit U. As shown in FIG. 1, the battery unit U has output terminals P1 to P3 and an electric path in the unit. A lead battery 11, a starter 13, and a load R12 are connected to the output terminal P1. A rotary electric machine 30 is connected to the output terminal P2. A load R11 is connected to the output terminal P3.

The electric path in the unit electrically connects the output terminals P1 to P3 to each other, and has an electric path L1 and an electric path L2 for connecting the lead battery 11 and the lithium ion battery 12. One end of the electric path L1 is connected to the output terminal P1 and the other end is connected to the lithium ion battery 12. The connection point N1 which is an intermediate point of the electric path L1 is connected to the output terminal P3. The path between the electric path L1 and N1-P3 is a small current path assuming that a small current flows as compared with the electric path L1 side (that is, a small current path having a smaller allowable current than the electric path L1). Yes, the load R11 is energized from the batteries 11 and 12 via this path.

Further, among the electric paths L1, the switch SW1 is provided in the path L11 (first path) on the side of the lead battery 11 with respect to the connection point N1. A switch SW2 is provided in the path L12 (second path) of the electric path L1 on the side of the lithium ion battery 12 with respect to the connection point N1.

By alternately switching the switches SW1 and SW2 on and off, one of the batteries 11 and 12 is connected to the load R11. Specifically, when the switch SW1 is turned on and the switch SW2 is turned off, the lead battery 11 and the load R11 are electrically connected, and the load R11 is supplied with power from the lead battery 11. When the switch SW1 is turned off and the switch SW2 is turned on, the lithium ion battery 12 and the load R11 are electrically connected, and the load R12 is supplied with power from the lithium ion battery 12.

One end of the electric path L2 is connected to the connection point N3 between the output terminal P1 and the switch SW1, and the other end is connected to the connection point N2 between the switch SW4 and the lithium ion battery 12. The connection point N4, which is an intermediate point of the electric path L2, is connected to the output terminal P2. The path between the electric paths L2 and N4-P2 is a large current path assuming that an input / output current to the rotary electric machine 30 flows, and the mutual batteries 11 and 12 and the rotary electric machine 30 pass through this path. Will be energized.

Further, a switch SW3 is provided in the path of the electric path L2 on the side of the lead battery 11 with respect to the connection point N4. A switch SW4 is provided in the path on the side of the lithium ion battery 12 with respect to the connection point N4.

By switching the switches SW3 and SW4 on and off, the electrical connection state between the rotary electric machine 30 and the batteries 11 and 12 can be switched. Specifically, when the switch SW3 is turned on, the lead battery 11 and the rotary electric machine 30 are electrically connected to supply power from the lead battery 11 to the rotary electric machine 30, or the lead battery 11 is generated by the power generated by the rotary electric machine 30. Can be charged. When the switch SW4 is turned on, the lithium ion battery 12 and the rotary electric machine 30 are electrically connected to supply power from the lithium ion battery 12 to the rotary electric machine 30, or the lithium ion battery 12 is powered by the generated power of the rotary electric machine 30. It can be charged.

These switches SW1 to SW4 are configured by using semiconductor switching elements such as MOSFETs, transistors, and IGBTs. When each switch SW1 to SW4 is composed of a semiconductor switching element, when the semiconductor switching element is turned off, a current flows through a parasitic diode peculiar to the semiconductor switch. Therefore, each switch SW1 to SW4 is configured by connecting at least two semiconductor switching elements in series so that the directions of the parasitic diodes are opposite to each other. With such a configuration, if the pair of semiconductor switching elements is turned off, the current component flowing through the parasitic diode of the pair of semiconductor switching elements can also be cut off. Each switch SW1 to SW4 can be configured by at least one semiconductor switch. Further, each switch SW1 to SW4 may be configured by a mechanical switch such as a relay.

Further, among the switches SW1 to SW4, the diode portion D and the current sensor I are provided in parallel with respect to the switch SW1 and the switch SW2. Specifically, a path bypassing the switch SW1 is connected in parallel to the switch SW1, and a diode section D1 and a current sensor I1 are connected in series to the path. The diode unit D1 is arranged so that a forward current flows from the lead battery 11 to the load R11, and is configured by using at least one diode. In FIG. 1, the diode section D1 is configured by connecting two diodes in series. Each diode is arranged so that the cathode is on the load R11 side and the anode is on the lead battery 11 side.

Similarly, a path bypassing the switch SW2 is connected in parallel to the switch SW2, and the diode section D2 and the current sensor I2 are connected in series to the path. The diode portion D2 is arranged so that a forward current flows from the lithium ion battery 12 to the load R11, and is configured by using at least one diode. In FIG. 1, the diode section D2 is configured by connecting two diodes in series. Each diode is arranged so that the cathode is on the load R11 side and the anode is on the lithium ion battery 12 side.

The control device 100 is a microcomputer configured to include a CPU, ROM, RAM, I / O interface, etc., and when the CPU executes a program stored in the ROM, the switch control unit 101 and the current detection unit 102 Realize each function.

First, the current detection unit 102 reads the current detection value by the current sensor I1 and recognizes the current value flowing through the diode unit D1. Further, the detected value of the current by the current sensor I2 is read, and the current value flowing through the diode portion D2 is recognized.

The switch control unit 101 controls a switch for switching on and off of each switch SW1 to SW4. Specifically, the switch control unit 101 switches the electrical connection state between the lead battery 11 and the rotary electric machine 30 by switching the switch SW3 on and off. By switching the switch SW4 on and off, the electrical connection state between the lithium ion battery 12 and the rotary electric machine 30 is switched.

Further, the switch control unit 101 alternately switches the switches SW1 and SW2 on and off so as to supply power to the load R11 from one of the lead battery 11 and the lithium ion battery 12. That is, when power is supplied to the load R11 from the lead battery 11, the switch SW1 is turned on and the switch SW2 is turned off. When power is supplied to the load R11 from the lithium ion battery 12, the switch SW1 is turned off and the switch SW2 is turned on.

By the way, the voltage (SOC) of the battery supplying power to the load R11 gradually decreases. Therefore, when the voltage (SOC) of the battery that is supplying power drops to a predetermined lower limit voltage, switch control is performed with respect to the load R11 in order to prevent the battery from being over-discharged. It may be switched so that power is supplied from the other battery. However, during switch control, if one switch is turned off and the other switch is turned on at the same time, both switches are turned off momentarily, and the power supply to the load may be interrupted.

In order to avoid this, it is conceivable to provide a situation in which both switches are turned on at the same time by first switching the off switch to on and then switching the on switch to off. However, when both switches SW1 and SW2 are turned on, a through current flows, which may be a burden on the switches SW1 and SW2.

Therefore, in the switch control unit 101, a current of a predetermined value or more is flowing through any of the diode units D (D1, D2) provided in the path bypassing the switches SW1 and SW2, and the current is flowing through the diode unit D. The states of both switches SW1 and SW2 are switched on condition that the power supply path to the load R11 is secured. At this time, the switch control unit 101 first switches the on state switch to off, and then switches the off state switch to on, in the order of switching the on / off state of both switches SW1 and SW2. This prevents both switches from being on at the same time.

Specifically, when switching the state of each switch in the state where the switch SW1 is on and the switch SW2 is off, the switch SW1 is first switched off and then the switch SW2 is switched on. When switching the state of each switch in the state where the switch SW1 is off and the switch SW2 is on, the switch SW2 is first switched off and then the switch SW1 is switched on.

When the on / off states of the switches are switched in such an order, a moment when both switches SW1 and SW2 are turned off occurs. However, even if both switches SW1 and SW2 are turned off, a power supply path from the power supply to the load is secured through the diode portion D during that time. Therefore, it is possible to switch the on / off state of each switch while avoiding interruption of power supply to the load.

Specifically, in a situation where the switch SW1 is off and the switch SW2 is on and power is supplied from the lithium ion battery 12 to the load R11, the voltage (SOC) of the lithium ion battery 12 gradually decreases. On the other hand, since the lead battery 11 does not supply power to the load R11, the voltage does not decrease.

Therefore, in this case, as the voltage of the lithium ion battery 12 decreases, the potential difference between the two batteries 11 and 12 expands, and when the potential difference becomes a magnitude corresponding to the forward voltage of the diode portion D1, the diode portion D1 becomes large. It is conducted and a forward current flows. That is, the feeding path from the lead battery 11 to the load R11 is secured via the diode portion D1. Then, in such a situation that the feeding path to the load R11 is secured via the diode portion D1, the switch SW2 is turned off and then the switch SW1 is turned on.

Similarly, even in a situation where the switch SW1 is on and the switch SW2 is off and power is being supplied from the lead battery 11 to the load R11, the power supply path from the lithium ion battery 12 to the load R11 via the diode portion D2. If the switch SW1 is turned off and then the switch SW2 is turned on, the power supply to the load R11 is interrupted even if both switches SW1 and SW2 are momentarily turned off. Can be avoided.

Further, regarding the diode portion D, when the current flowing through the diode portion D becomes a predetermined value or more, any of the switches SW1 and SW2 is switched on, so that the current of the diode portion D or more is a predetermined value or more. It will not continue to flow. As a result, the diode portion D is protected.

By the way, the diode has a characteristic that when the temperature rises, the diode conducts and the forward voltage required for the forward current to flow decreases. Therefore, when the temperature of the diode becomes high, the diode is conducted even if the potential difference between the two batteries 11 and 12 is smaller than the expected size. In this case, the period required from the previous conduction of the diode to the next conduction is shortened. Further, since the diode is conducted again before the temperature of the diode is sufficiently lowered, the temperature of the diode rises, which may cause a failure of the diode. Further, regarding the switches SW1 and SW2, the on / off state is frequently switched, which is disadvantageous in terms of maintaining durability.

Therefore, in the present embodiment, the diode section D is configured by connecting a plurality of diodes in series. In FIG. 1, two diodes are connected in series to form a diode portion D. When the diode portion D is configured by using a plurality of diodes in this way, the forward voltage required for the forward current to flow in the diode portion D is compared with the case where the diode portion D is composed of a single diode. Becomes larger.

The fact that the forward voltage required for the diode portion D to conduct is large means that the potential difference between the first power supply and the second power supply required for the diode portion D to conduct is large. Then, in order to increase the potential difference between the first power supply and the second power supply, it is necessary that the voltage of the power supply that is supplying power to the load R11 is further lowered.

In this case, it takes time for the diode portion D to conduct, and it becomes easy to secure the time for the diode to be cooled by heat dissipation. As a result, the temperature rise of the diode can be suppressed. Further, with respect to the switches SW1 and SW2, since the period until the on / off state is switched becomes long, it is advantageous in terms of maintaining the durability.

In order to lower the temperature of the diode portion D, it is conceivable to provide a heat radiating member for the diode portion D, but in order to provide the radiating member, it is necessary to increase the cost and increase the size of the device. On the other hand, in the above configuration, the heat dissipation function of the diode portion D can be enhanced only by increasing the number of inexpensive diodes, which is advantageous in terms of cost and the like when configuring the device.

Next, an operation example of the power supply system of the present embodiment is shown with reference to FIG. In FIG. 2, the current flowing into the load R11 is shown as “A”, the voltage of the lead battery 11 is shown as “VPb”, the voltage of the lithium ion battery 12 is shown as “VLi”, and the voltage of the load R11 is shown as “VR”. .. Further, in FIG. 2, the threshold value “Th1” of the current flowing through the diode portion D when the state of the switch is switched, and the threshold value at which the potential difference between the two batteries 11 and 12 becomes a magnitude corresponding to the forward voltage of the diode portion D. It is indicated as "Th2".

At time t1, the switch SW1 is on and the switch SW2 is off, and the load R11 is supplied with power from the lead battery 11. Therefore, after time t1, the voltage VPb of the lead battery 11 gradually decreases, and the potential difference between the voltage VPb and the voltage VLi gradually increases accordingly.

At time t2, when the potential difference between the voltage VPb and the voltage VLi becomes equal to or higher than the forward voltage of the diode section D2, a current flows from the lithium ion battery 12 to the load R11 via the diode section D2. That is, after time t2, power is supplied from the lead battery 11 to the load R11 via the switch SW1, and power is also supplied from the lithium ion battery 12 to the load R11 via the diode unit D2.

When the current flowing through the diode section D2 reaches a predetermined threshold value Th1 at time t3, the switch SW1 is first switched off, and then the switch SW2 is switched on at time t4 thereafter. Therefore, during the time t3 to t4, both switches SW1 and SW2 are in the off state, so that power is not supplied via both switches SW1 and SW2. However, during the time t3 to t4, the power supply to the load R11 is continued via the diode portion D2.

Since the switch SW1 is off and the switch SW2 is on after the time t4, the load R11 is supplied with power from the lithium ion battery 12 via the switch SW2. Therefore, after the time t4, the voltage VLi of the lithium ion battery 12 gradually decreases, and accordingly, the potential difference between the voltage VPb and the voltage VLi gradually decreases.

At time t5, regenerative power generation is performed by the rotary electric machine 30. Although not shown here, specifically, the switch SW3 and the switch SW4 are switched on by the switch control unit 101, and the rotary electric machine 30 and both batteries 11 and 12 are electrically connected. In this state, the generated power generated by the regenerative power generation is supplied to both batteries 11 and 12, so that both batteries 11 and 12 are charged and their voltage rises. During this period, the load R11 is continuously supplied with power from the lithium ion battery 12 via the switch SW2.

When the charging of both batteries 11 and 12 is completed at time t6, the switch SW3 and the switch SW4 are switched off (not shown). After that, the load R11 is continuously supplied with power from the lithium ion battery 12 via the switch SW2, and the voltage of the lithium ion battery 12 gradually decreases accordingly.

At time t7, when the potential difference between the voltage VPb and the voltage VLi becomes equal to or higher than the forward voltage of the diode section D1, a current flows from the lead battery 11 to the load R11 via the diode section D1. That is, after time t7, power is supplied from the lithium ion battery 12 to the load R11 via the switch SW2, and power is also supplied from the lead battery 11 to the load R11 via the diode unit D1.

When the current flowing through the diode section D1 reaches the threshold value Th1 at time t8, the switch SW2 is first switched off, and then the switch SW1 is switched on at time t9. Therefore, during the time t8 to t9, both switches SW1 and SW2 are in the off state, so that power is not supplied via both switches SW1 and SW2. However, during the time t8 to t9, the power supply to the load R11 is continued via the diode portion D1.

After time t9, the load R11 is supplied with power from the lead battery 11.

As described above, by repeating the switch control for switching the switches SW1 and SW2 on and off, the power supply to the load R11 is interrupted and the through current flows through both switches SW1 and SW2 while avoiding the flow to the load R11. Power supply will be continued.

(Transformation example)
The switch control unit 101 may switch the states of the switches SW1 and SW2 at the same time. More specifically, with reference to the execution example of FIG. 2, when the current flowing through the diode portion D2 reaches the threshold value Th1 at time t3, the states of both switches SW1 and SW2 are switched at the same time. You may do it. Even in this case, even if a moment when both switches SW1 and SW2 are turned off occurs, it is possible to avoid interruption of the power supply to the load R11 and continue to supply power to the load R11.

According to the above, the following excellent effects can be obtained.

When the switch SW1 is off and the switch SW2 is on, power is supplied from the lithium ion battery 12 to the load R11, and the voltage of the lithium ion battery 12 gradually decreases. On the other hand, since the power is not supplied from the lead battery 11 to the load R11, the voltage of the lead battery 11 does not decrease. Therefore, when the voltage of the lithium ion battery 12 decreases, the potential difference between the lead battery 11 and the lithium ion battery 12 increases. When the potential difference between the lead battery 11 and the lithium ion battery 12 becomes large enough to correspond to the forward voltage of the diode portion D1, the diode portion D1 is conducted and a forward current flows. That is, the feeding path from the lead battery 11 to the load R11 is secured via the diode portion D1.

Then, in the situation where the power supply path to the load R11 is secured via the diode portion D1 in this way, if the switch SW1 is switched on and the switch SW2 is switched off, both switches SW1 and SW2 are assumed to be switched. Even if it is turned off momentarily, it is possible to avoid interruption of power supply to the load R11.

Similarly, if the current flowing through the diode section D2 is equal to or higher than a predetermined value and the power supply path to the load R11 is secured via the diode section D2, the switch SW1 can be turned off and the switch SW2 can be turned on. Even if both switches SW1 and SW2 are momentarily turned off, it is possible to avoid interruption of power supply to the load R11.

Further, regarding the diode portion D, when the current flowing through the diode portion D exceeds a predetermined value, the switch is switched on, so that the current exceeding the predetermined value does not continuously flow through the diode portion D. Become. As a result, the diode portion D is protected.

-The diode section D is configured by connecting a plurality of diodes in series. As a result, the forward voltage required for the forward current to flow in the diode portion D can be increased as compared with the case where the diode portion D is composed of a single diode. The fact that the voltage required for the diode portion D to conduct becomes large means that the potential difference between the lead battery 11 and the lithium ion battery 12 required for the diode portion D to conduct becomes large. Then, in order to increase the potential difference between the lead battery 11 and the lithium ion battery 12, it is necessary that the voltage of the power source that supplies power to the load R11 is further reduced.

In this case, it takes time for the diode portion D to conduct, and it becomes easy to secure the time for the diode portion D to be cooled by heat dissipation. As a result, the temperature rise of the diode portion D can be suppressed. Further, regarding the switch, since the period until the on / off state is switched is long, it is advantageous in terms of maintaining the durability.

In order to lower the temperature of the diode portion D, it is conceivable to provide a heat radiating member for the diode portion D, but in order to provide the radiating member, it is necessary to increase the cost and increase the size of the device. On the other hand, in the above configuration, the heat dissipation function of the diode portion D can be enhanced only by increasing the number of inexpensive diodes, which is advantageous in terms of cost and the like when configuring the device.

-When switching the on / off state of switch SW1 and switch SW2, if one switch is turned off and the other switch is turned on at the same time, both switches are turned on momentarily and a through current flows, which is the cause of switch SW1 and switch SW2. It may be a burden on the switch SW2. Therefore, as the order of switching the on / off states of both switches SW1 and SW2, the switch in the on state is first switched off, and then the switch in the off state is switched on. This prevents both switches SW1 and SW2 from being turned on at the same time.

For example, when the switch SW1 is on and the switch SW2 is off, the current flowing through the diode unit D2 becomes a predetermined value or more, and when it is time to switch the switch state, the switch SW1 is switched off first. Therefore, the switch SW2 is switched on. By switching the switch states in this order, the influence of the through current can be avoided.

If the switch states are switched in the above order, there will be a moment when both the switch SW1 and the switch SW2 are turned off. However, even if both switches SW1 and SW2 are turned off, a power supply path from the power supply to the load R11 is secured via the diode portion D2 during that time. Therefore, the on / off state of each switch can be switched while avoiding the interruption of the power supply to the load R11.

When the load R11 is an in-vehicle device EL1 whose state is reset when the applied voltage fluctuates beyond a predetermined range, the above configuration is applied to the in-vehicle device EL1. Since the power supply is stably performed, it is possible to suppress the occurrence of inconveniences such as unnecessary reset.

-When a rotary electric machine 30 having a power generation function of generating power by the power of an engine and an electric function of being rotated by power supply from a power source is connected instead of the load R11, the above configuration is applied. Since the power is stably supplied to the rotary electric machine 30, the operation of the rotary electric machine 30 can be stabilized.

The present invention is not limited to the description of the above embodiment, and may be implemented as follows. In the following description, the same configurations as above will be assigned the same reference numerals and details will be omitted. In addition, each embodiment can be used by combining them with each other or by selectively selecting them.

(Second Embodiment)
In FIG. 1 above, when an abnormality occurs in any of the switches SW1 and SW2 due to an open failure or the like, the switch cannot be turned on correctly even if the switch is controlled to be turned on (the switch). (Because) remains off), it becomes impossible to supply power from the power supply to the load via the switch.

In this case, the power supply path to the load is secured by the current flowing through the diode portion D provided in the path bypassing the switch in which the abnormality occurs. However, if current continues to flow through a diode that is less durable than a switch, it causes a diode failure. Therefore, it is advisable to provide a bypass switch BSW for switching the electrical connection state between each power supply and the load in the path bypassing the switch and the diode portion D.

More specifically, as shown in FIG. 3, first, a bypass switch BSW1 for switching the electrical connection state between the lead battery 11 and the load R11 is provided in a path bypassing both the switch SW1 and the diode portion D1. Similarly, a bypass switch BSW2 for switching the electrical connection state between the lithium ion battery 12 and the load R11 is provided in a path bypassing both the switch SW2 and the diode portion D2. For example, as the bypass switches BSW1 and BSW2, normally closed mechanical switches that are closed when the power supply system is stopped are used. The on / off of each bypass switch BSW1 and BSW2 is switched by the switch control unit 101.

With such a configuration, it is possible to supply power from the lead battery 11 to the load R11 via the switch SW1 or to supply power from the lithium ion battery 12 to the load R11 via the switch SW2. When a power supply abnormality that cannot be performed occurs, the switch control unit 101 switches on the bypass switch BSW1 (BSW2) provided in the path bypassing the switch SW1 (SW2) to turn on the bypass switch BSW1 (BSW2). The power supply to the load R11 is continued through.

Specifically, when the switch SW1 is off and the switch SW2 is on, the switch SW1 is switched on and the switch SW2 is switched off on condition that a current equal to or higher than a predetermined value is flowing through the diode portion D1. However, at this time, if the switch SW1 is open and failed, the switch SW1 remains off. In this case, the current continues to flow to the load R11 via the diode portion D1, which causes a failure of the diode portion D1.

Therefore, even if the switch control unit 101 performs a process of switching the states of the switches SW1 and SW2, for example, the bypass switch BSW1 is turned on on condition that the current of the diode unit D1 continues to be equal to or higher than a predetermined state. Switch. As a result, the state in which the power is supplied to the load R11 via the diode portion D1 is switched to the state in which the power is supplied to the load R11 via the bypass switch BSW1.

As described above, even if the switches SW1 and SW2 fail, the power supply to the load R11 can be continuously performed while protecting the diode portion D.

As described above, in the second embodiment, the bypass switch BSW for switching the electrical connection state between the batteries 11 and 12 and the load R11 is provided in the path bypassing the switches SW1 and SW2. Specifically, as the bypass switch BSW, a bypass switch BSW1 for switching the electrical connection state between the lead battery 11 and the load R11 is provided in the path bypassing the switch SW1, and the lithium ion battery is provided in the path bypassing the switch SW2. A bypass switch BSW1 for switching the electrical connection state between the 12 and the load R11 is provided.

With such a configuration, for example, even if a power supply abnormality occurs in which power cannot be supplied from the lead battery 11 (lithium ion battery 12) to the load R11 via the switch SW1 (or switch SW2). If the bypass switch BSW connected in parallel to the switch is switched on, the power supply to the load R11 can be continued while protecting the diode portion D.

(Third Embodiment)
As shown in FIG. 4, among the switches SW1 to SW4, the diode portion D is connected in parallel to the switch SW1 on the path L11 connecting the lead battery 11 and the load R11. Further, the output terminal P4 is provided in the battery unit U, and the output terminal P4 and the lead battery 11 or the like are connected outside the battery unit U. Further, in the battery unit U, a bypass switch BSW1 is provided on a path connecting the output terminal P4 and the connection point N5 between the load R11 and the switch SW1 (connection point N1).

Further, the control device 100 is provided with a function of an abnormality determination unit 103 for determining that a power supply abnormality in which power cannot be supplied to the load R11 via the switch SW1 has occurred. Even if the switch control unit 101 controls the switch SW1 to be turned on, the abnormality determination unit 103 loads when it is detected that the detected value of the current flowing through the switch SW1 does not exceed a predetermined value. It is determined that a power supply abnormality has occurred in which power cannot be supplied to R11. The current value of the current flowing through the switch SW1 is detected by the current detection unit 102.

In such a configuration, even if an abnormality such as an open failure occurs in the switch SW1 and a power supply abnormality occurs in which the lead battery 11 cannot supply power to the load R11 via the electric path L1 (path L11), the switch control is performed. If the bypass switch BSW1 is switched on by the unit 101, the power supply from the lead battery 11 to the load R11 can be continued via the bypass switch BSW1 (bypass path).

However, it is inevitable that the power supply from the lead battery 11 to the load R11 will be interrupted between the time when the power supply abnormality is determined and the time when the bypass switch BSW1 is switched on by the switch control unit 101.

Therefore, the diode portion D is connected in parallel to at least one of the switch SW1 and the bypass switch BSW1 so that a forward current flows from the lead battery 11 to the load R11. Note that FIG. 4 shows an example in which the bypass switch BSW1 is connected in parallel to the switch SW1. With such a configuration, from the time when the abnormality determination unit 103 determines that a power supply abnormality has occurred until the bypass switch BSW1 is switched on, the lead battery 11 to the load R11 via the diode unit D. It is possible to secure a power supply route to.

Here, with reference to FIG. 5, the processing performed by the control device 100 in the power supply system of the third embodiment will be specifically described. The process shown in FIG. 5 is repeated by the control device 100 at a predetermined cycle while the power supply system is activated. When the power supply system is stopped, the control device 100 does not control the switch, but the bypass switch BSW1 is on and the control device 100 is supplied with dark current from the lead battery 11, so that the power supply system It is possible to recognize the state of (whether or not it is started, etc.).

First, the control device 100 determines whether or not the power supply system is in the activated state (S11). This process is positively determined when the on-vehicle ignition switch (not shown) is on. If the power supply system is not in the activated state (S11: NO), the bypass switch BSW1 is kept on. On the other hand, if the power supply system is in the activated state (S11: YES), it is determined whether or not both the switches SW1 and SW2 are off (S12). This process can be recognized by the current detection unit 102 detecting the current flowing through each of the switches SW1 and SW2. If both switches SW1 and SW2 are not off (S12: NO), the bypass switch BSW1 is turned off (S13). In this case, power is supplied to the load R11 via any of the switches SW1 and SW2. On the other hand, if both switches SW1 and SW2 are off (S12: YES), the bypass switch BSW1 is turned on (S14). In this case, power is supplied to the load R11 via the bypass switch BSW1.

An execution example of the processing of the power supply system of the third embodiment will be described. Here, FIG. 6 shows an example of processing when a switch SW2 has an open failure while the switch SW1 is on. FIG. 7 shows an example of processing when the switch SW2 has an open failure while the switch SW2 is on. In any of the execution examples, the ignition switch is switched on before the time t1, the power supply system is in the activated state, and the switch control by the switch control unit 101 is started.

In FIG. 6, at time t1, the switch SW1 is on, the switch SW2 is off, and the bypass switch BSW1 is off, and power is supplied from the lead battery 11 to the load R11 via the switch SW1.

If the switch SW2 fails to open at time t2, switch control is performed to switch the switch SW1 off and the switch SW2 on at the subsequent time t3, but the switch SW2 cannot be properly switched to the on state. Switches SW1 and SW2 are turned off. When it is determined that a power supply abnormality has occurred, the bypass switch BSW1 is switched on at the subsequent time t4.

Therefore, during the time t3 to t4, all of the switches SW1 and SW2 and the bypass switch BSW1 are in the off state. However, during this period, the feeding path from the lead battery 11 to the load R11 is secured by the diode portion D1 connected in parallel to the switch SW1. Therefore, it is possible to avoid interruption of power supply to the load R11.

In FIG. 7, at time t1, the switch SW1 is off, the switch SW2 is on, and the bypass switch BSW1 is off, and power is supplied from the lithium ion battery 12 to the load R11 via the switch SW2.

When the switch SW2 is switched off due to some abnormality at time t2, all of the switches SW1 and SW2 and the bypass switch BSW1 are turned off. When it is determined that a power supply abnormality has occurred, the bypass switch BSW1 is switched on at the subsequent time t3. Therefore, between the times t2 and t3, all of the switches SW1 and SW2 and the bypass switch BSW1 are in the off state. However, during this period, the feeding path from the lead battery 11 to the load R11 is secured by the diode portion D1 connected in parallel to the switch SW1. Therefore, the power supply to the load R11 is interrupted, but it is avoided.

(Transformation example)
In the third embodiment described above, if the bypass switch BSW and the diode section D are similarly connected in parallel to the switch SW2 of the electric path L1 (path L12) connecting the lithium ion battery 12 and the load R11, Lithium via the diode section D from the time when a power supply abnormality that cannot supply power to the load R11 via the switch SW2 is determined until the bypass switch BSW connected in parallel to the switch SW2 is switched on. A power supply path from the ion battery 12 to the load R11 can be secured.

(Fourth Embodiment)
In the above, in order to avoid interruption of power supply to the load R11 when both batteries 11 and 12 are alternately connected to the load R11, the diode portion D and the bypass switch BSW are provided to the switches SW1 and SW2. You are connected. In addition to this, when the rotary electric machine 30 is operated as a load by the power running function, it is preferable to configure the rotary electric machine 30 so that the power supply to the load is not interrupted.

Specifically, as shown in FIG. 8, among the switches SW1 to SW4, the diode portion D2 is also connected in parallel to the switch SW3 that connects the lead battery 11 and the rotary electric machine 30. Further, a bypass switch BSW2 for electrically connecting the lead battery 11 and the rotary electric machine 30 is provided in the path bypassing the switch SW3. Specifically, the bypass switch BSW2 is provided in the path connecting the output terminal P4 and the connection point N4 which is an intermediate point of the electric path L2.

In such a configuration, when the switch SW3 is turned on and power is supplied from the lead battery 11 to the rotary electric machine 30, the abnormality determination unit 103 recognizes that the switch SW3 cannot be switched on (switch SW3). When a power supply abnormality in which power cannot be supplied from the lead battery 11 to the rotary electric machine 30 is recognized), the switch control unit 101 switches the bypass switch BSW2 on. As a result, the power supply from the lead battery 11 to the rotary electric machine 30 is continued via the bypass switch BSW2. Also in this case, both the switch SW3 and the bypass switch BSW2 are turned off between the time when the power supply abnormality is determined and the time when the bypass switch BSW2 is switched on. However, also in this case, the power supply path from the lead battery 11 to the rotary electric machine 30 is secured via the diode portion D2 connected in parallel to the switch SW3 (bypass switch BSW2). Therefore, it is possible to avoid interruption of the power supply path to the rotary electric machine 30 at the timing when the states of the switch SW3 and the bypass switch BSW2 are switched.

As described above, in the fourth embodiment, the diode portion D is connected in parallel to at least one of the switch SW3 and the bypass switch BSW2 so that the forward current flows from the lead battery 11 to the rotary electric machine 30. .. With such a configuration, it is possible to secure a power supply path from the lead battery 1 to the rotary electric machine 30 even after it is determined that a power supply abnormality has occurred until the bypass switch BSW2 is switched on. can.

(Transformation example)
In the fourth embodiment described above, the diode portion D and the bypass switch BSW are similarly connected in parallel to the switch SW4 provided in the path connecting the lithium ion battery 12 and the rotary electric machine 30. Even if an abnormality such as an open failure occurs in the switch SW4, it is possible to avoid interruption of the power supply path from the lithium ion battery 12 to the rotary electric machine 30.

(Other embodiments)
In each of the above embodiments, the various in-vehicle devices EL1 and EL2 are provided separately in a plurality of systems such as the load R11 and the load R12, but the various in-vehicle devices EL1 and EL2 are provided in one system. You may be able to do it. For example, in FIG. 1, the configuration related to the load R12 may be omitted.

11 ... Lead-acid battery, 12 ... Lithium-ion battery, 101 ... Switch control unit, 102 ... Current detection unit, D ... Diode unit, D1 ... Diode unit, D2 ... Diode unit, L1 ... Electric path, L11 ... Path, L12 ... Path , SW1 ... switch, SW2 ... switch.

Claims (10)

The load (R11) connected to the electric path (L1) connecting the first power supply (11) and the second power supply (12), and
Among the electric paths, a first switch (SW1) provided in the first path (L11) connecting the first power supply and the load, and
Of the electric paths, a second switch (SW2) provided in the second path (L12) connecting the second power supply and the load, and
A diode portion (D) composed of at least one diode, the first diode portion (D1) connected in parallel to the first switch so that a forward current flows from the first power supply to the load. And the second diode section (D2) connected in parallel to the second switch so that a forward current flows from the second power supply to the load.
A current detection unit (102) that detects the current flowing through the first diode unit and the second diode unit, and the current detection unit (102).
A switch control unit (101) that controls so that one of the first switch and the second switch is on and the other is off is provided.
The switch control unit
The first switch is turned on and the second switch is turned off on condition that the current flowing through the first diode portion is equal to or higher than a predetermined value.
A power supply system characterized in that the first switch is turned off and the second switch is turned on on condition that the current flowing through the second diode portion is equal to or higher than a predetermined value. According to claim 1, the diode portion is configured by connecting a plurality of the diodes in series so that the forward current flows when the potential difference between the first power supply and the second power supply becomes a predetermined value or more. The power supply system described. According to claim 1 or 2, when the switch control unit switches the on / off state of the first switch and the second switch, the switch in the on state is switched off and then the switch in the off state is switched on. The power supply system described. The first bypass switch (BSW1) provided in the path bypassing the first switch and switching the electrical connection state between the first power supply and the load, and the path bypassing the second switch are provided. A second bypass switch (BSW2) that switches the electrical connection state between the second power supply and the load, and a bypass switch that includes at least one of them.
When the first bypass switch is provided, power cannot be supplied from the first power supply to the load via the first path, provided that the first switch is on. When it is determined that an abnormality has occurred and the second bypass switch is provided, the second power supply can be used from the second power source via the second path, provided that the second switch is on. It is equipped with an abnormality determination unit (103) for determining that a power supply abnormality has occurred in which power cannot be supplied to the load.
The control unit controls so that one of the first switch and the first bypass switch is on and the other is off, one of the second switch and the second bypass switch is on, and the other is off. There,
The switch control unit
When the first bypass switch is provided, the state of the first switch is on the condition that the first switch is on and the power supply abnormality has occurred via the first path. Regardless of, the first bypass switch is turned on,
When the second bypass switch is provided, the first is provided on condition that the second switch is turned on and it is determined that the power supply abnormality has occurred via the second path. 2. The power supply system according to any one of claims 1 to 3, wherein the second bypass switch is turned on regardless of the state of the two switches. An open / close switch (SW1) provided in the electric path (L1) connecting the power supply (11) and the load (R11), and
A bypass switch (BSW1) provided in a path that bypasses the open / close switch and switches the electrical connection state between the power supply and the load.
A diode section (D) configured using at least one diode and connected in parallel to at least one of the open / close switch and the bypass switch so that a forward current flows from the power supply to the load.
A switch control unit (101) that controls so that one of the open / close switch and the bypass switch is on and the other is off.
An abnormality determination unit (103) for determining that a power supply abnormality in which power cannot be supplied from the power supply to the load via the electric path occurs when the open / close switch is turned on is provided.
The switch control unit is a power supply system characterized in that when it is determined that the power supply abnormality has occurred, the bypass switch is turned on regardless of the state of the open / close switch. An open / close switch, the first open / close switch (SW1) provided in the first electric path (L11) connecting the first power supply (11) and the load (R11), and the second power supply (12) and the load. The second open / close switch (SW2) provided in the second electric path (L12) to connect the
A bypass switch (BSW1) provided in a path that bypasses the first open / close switch and switches the electrical connection state between the first power supply and the load.
A diode portion (D) connected in parallel to at least one of the first open / close switch and the bypass switch so that a forward current flows from the first power supply to the load.
A first switch control unit (101) that controls so that one of the first open / close switch and the second open / close switch is on and the other is off.
A second switch control unit (101) that turns on the bypass switch, provided that both the first open / close switch and the second open / close switch are off.
A power supply system characterized by being equipped with. The power supply system according to any one of claims 1 to 6, wherein the load is an in-vehicle device (EL1) whose state is reset when the applied voltage fluctuates beyond a predetermined range. The first open / close switch (SW1) provided in the first electric path (L1) connecting the power supply (11) and the first load (R11), and
A second open / close switch (SW3) provided in the second electric path (L21) connecting the power supply and the second load (30), and
A first bypass switch (BSW1) provided in a path that bypasses the first open / close switch and switches an electrical connection state between the power supply and the first load.
A second bypass switch (BSW2) provided in a path that bypasses the second open / close switch and switches the electrical connection state between the power supply and the second load.
A first diode section (D1) connected in parallel to at least one of the first open / close switch and the first bypass switch so that a forward current flows from the power supply to the first load.
A second diode portion (D2) connected in parallel to at least one of the second open / close switch and the second bypass switch so that a forward current flows from the power supply to the second load.
A switch control unit (101) for switching on and off of the first open / close switch and the second open / close switch,
Even if the first open / close switch is switched on by the switch control unit, power cannot be supplied to the first load, or even if the second open / close switch is switched on by the switch control unit. It is provided with an abnormality determination unit (103) for determining that a power supply abnormality has occurred when power supply to the second load cannot be performed.
When it is determined that the power supply abnormality has occurred, the switch control unit is provided in a path that bypasses the open / close switch regardless of the state of the open / close switch in the path in which the power supply abnormality is determined. A power supply system characterized in that the bypass switch is turned on. The first open / close switch (SW1) provided in the first electric path (L1) connecting the power supply (11) and the first load (R11), and
A second open / close switch (SW3) provided in the second electric path (L21) connecting the power supply and the second load (30), and
A first bypass switch (BSW1) provided in a path that bypasses the first open / close switch and switches an electrical connection state between the power supply and the first load.
A second bypass switch (BSW2) provided in a path that bypasses the second open / close switch and switches the electrical connection state between the power supply and the second load.
A first diode section (D1) connected in parallel to at least one of the first open / close switch and the first bypass switch so that a forward current flows from the power supply to the first load.
A second diode portion (D2) connected in parallel to at least one of the second open / close switch and the second bypass switch so that a forward current flows from the power supply to the first load.
A first switch control unit (101) for switching on and off of the first open / close switch and the second open / close switch,
The first bypass switch is switched on on condition that the first open / close switch remains off even if the first open / close switch is switched on by the first switch control unit, and the first switch is switched on. With the second switch control unit (101) that switches the second bypass switch on, provided that the second open / close switch remains off even if the second open / close switch is switched on by the control unit. ,
A power supply system characterized by being equipped. The first load is an in-vehicle device (EL1) that needs to be applied with a voltage in a predetermined range.
The power supply system according to claim 8 or 9, wherein the second load is a rotary electric machine (30) having a power generation function of generating power by power of an engine and an electric function of being rotated by power supply from the power source.

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