JP2018113783A - Power supply device and power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device and a power supply system capable of regulating flow of currents to a storage battery side in the case of switching the storage battery.SOLUTION: When switching switches 23, 24, switch parts Sb3, Sa4 connected in parallel with parasitic diodes Db3, Da4 for regulating flow of currents from a connection point N4 side to a storage battery side are put in an open state. Also, the other switch parts Sa3, Sb4 among the switch parts Sa3, Sb3, Sa4, Sb4 of the switches 23, 24 are put in a closed state. Afterwards, any of electric paths L3, L4 is closed. Thus, when switching storage batteries 11, 12 for supplying power to an electric load 15 by switching the switches 23, 24, power can be continuously supplied to the electric load 15, and flow of currents from the connection point N4 side to the storage batteries 11, 12 side can be regulated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device applied to a power supply system having a plurality of storage batteries, and a power supply system.

  Conventionally, for example, as an in-vehicle power supply system mounted on a vehicle, two storage batteries (for example, a lead storage battery and a lithium ion storage battery) connected in parallel to an electric load are used. The structure which supplies electric power is known (for example, patent document 1). In this case, switches are provided in the electrical path between the electrical load and the lead-acid battery and the electrical path between the electrical load and the lithium ion storage battery, and the discharge of each storage battery is controlled by opening and closing each switch. .

JP 2014-36557 A

  By the way, when switching the storage battery of the supply source that supplies power to the electric load between the lead storage battery and the lithium ion storage battery, the power is continuously supplied by temporarily closing each switch. Is done. Thereby, when the electric power from the electric load is requested | required, it has prevented that a power defect arises. Such switching control is particularly necessary when there is a constant voltage load that always requires power.

  However, when each switch is closed and all the electrical paths are energized, if there is a voltage difference between the storage batteries, the current from the storage battery with a high voltage value is not limited to the electrical load. There is a possibility that it will flow to the storage battery side having a lower voltage as it is. In this case, a problem arises depending on the allowable current amount of each switch.

  This invention is made | formed in view of the said situation, and when changing a storage battery, it aims at providing the power supply device and power supply system which can control that an electric current flows into the storage battery side. .

  In order to solve the above-mentioned problem, a first invention is a power supply device applied to a power supply system in which a first storage battery and a second storage battery are connected in parallel to an electric load, wherein the first storage battery and the second storage battery are applied. A first opening / closing portion provided on the first storage battery side with respect to the electrical load in the electrical path between the storage battery and a second provided on the second storage battery side with respect to the connection point in the electrical path. An opening / closing part; and a control part for controlling the first opening / closing part and the second opening / closing part. The first opening part and the second opening / closing part are connected in series with a first switch and a second switch, respectively. The first switch and the second switch each include a diode and a switch unit connected in parallel with the diode, and the diode of the first switch The diodes of the second switch are provided in opposite directions, and the control unit switches the storage battery that supplies power to the electric load between the first storage battery and the second storage battery, Among the switch parts of the first opening and closing part and the second opening and closing part, the switch part connected to a diode that regulates the current from the connection point side to the storage battery side is opened, and the same as the switch part The switching unit that is in the opening / closing unit and in which the switch unit connected in series to the switching unit is in a closed state is controlled, and the switching unit is controlled to switch the storage battery during the switching intermediate state. The gist.

  In the switching intermediate state in which the switch part connected in parallel with the diode that regulates the current flow from the connection point side to the storage battery side is opened, from the storage battery side to the connection point side (that is, the electrical load) via the diode Although the current is allowed to flow, the current flowing to the opposite side (storage battery side) is restricted. For this reason, even if it switches to the state which supplies electric power to the electric load from both the storage battery sides, it can control that an electric current flows into one of the storage battery side from a connection point side by a voltage difference.

  2nd invention WHEREIN: The said switch part made into an open state in the said switching intermediate state is the said switch part which the said opening / closing part provided in the said storage battery side with a low voltage value among the said 1st storage battery and the said 2nd storage battery has It is a summary.

  When each storage battery has a voltage difference, when both the first electric path and the second electric path are energized, the current from the storage battery side with a high voltage value is not only an electric load, but the storage battery side with a low voltage value as it is There is a possibility of flowing. Therefore, by appropriately opening the switch connected in parallel with the diode that regulates the current to the storage battery with a low voltage value in the switching intermediate state, the switch that may cause an unintended overcurrent to flow is properly protected. Can do.

  3rd invention is equipped with the detection part which each detects the electric current which flows through the said 1st opening-and-closing part and the electric current which flows through the said 2nd opening-and-closing part, The said control part has the said 1st opening-closing part and the said 2nd opening-and-closing part Among the switch units having, all the switch units connected to the diode that regulates the current from the connection point side to the storage battery side are opened, and all the switch units other than the switch unit are closed. Based on the current detected by the detection unit in the switching intermediate state, the switching unit in which more current flows is identified from the first switching unit and the second switching unit, and the identified switching unit The gist of the invention is to switch the storage battery in a state where all of the switch portions of the battery are closed.

  In the switching intermediate state in which all the switch parts connected to the diode that regulates the current from the connection point side to the storage battery side are opened and all the switch parts other than the switch part are closed, more current is supplied. The flowing opening / closing part is specified, and the specified opening / closing part is in a closed state. For this reason, it is possible to secure a time for specifying an opening / closing part through which more current flows while continuing to supply power to the electric load. Moreover, it can suppress that a big electric current flows into a diode continuously.

  According to a fourth aspect of the present invention, when the specified opening / closing part is an opening / closing part that is required to be opened in switching of the storage battery, the control unit includes all of the switch parts included in the specified opening / closing part. The gist of the invention is to switch the storage battery by opening all the switch parts of the specified opening / closing part without making the battery closed.

  Thereby, it is possible to save the trouble of opening all the switch parts of the opening / closing part through which a larger amount of current is closed after being closed.

  In a fifth aspect of the present invention, the electric load includes a constant voltage load that requires power of a constant voltage, and either the first storage battery or the second storage battery separately from the constant voltage load, The gist is that an electrical load that temporarily requires power is connected.

  When electric power is supplied from an electric load that temporarily requires electric power, the voltage on either storage battery side may be temporarily reduced. Even in this case, by opening the switch unit connected in parallel with the diode that restricts the current flow to the storage battery side, by controlling each open / close unit to switch the storage battery, from the connection point side It can regulate that current flows into the storage battery side. Therefore, regardless of the power demand from the electric load, even if the voltage value on either storage battery side becomes low, the switch unit can be appropriately opened and closed for switching.

  The gist of the sixth invention is that a generator for supplying electric power is connected to one of the first storage battery and the second storage battery.

  When power is supplied from the generator, the voltage on either storage battery side may be temporarily increased. Even in this case, by opening the switch unit connected in parallel with the diode that restricts the current flow to the storage battery side, by controlling each open / close unit to switch the storage battery, from the connection point side It can regulate that current flows into the storage battery side. Therefore, regardless of the power generation status of the generator, even if the voltage value on either storage battery side becomes high, the switch unit can be appropriately opened and closed for switching.

  The gist of the seventh invention is that the control unit switches the storage battery when it is determined that an abnormality has occurred in the power supply device.

  For example, even if a power supply source or an electrical load other than the storage battery is connected to each storage battery, and there is a power supply or power request from them, when switching the storage battery, from the connection point side to the storage battery side with a low voltage No current flows. That is, the switch unit can be opened and closed without considering the power supply source other than the storage battery or the state of the electric load. For this reason, appropriate switching control can be performed when an abnormality occurs that requires quick switching.

  An eighth invention is a power supply system comprising an electrical load and a first storage battery and a second storage battery connected in parallel to the electrical load, and an electrical path between the first storage battery and the second storage battery. A first opening / closing portion provided closer to the first storage battery than the connection point with the electrical load, a second opening / closing portion provided closer to the second storage battery than the connection point in the electrical path, and the first An opening / closing part and a control part for controlling the second opening / closing part, wherein the first opening / closing part and the second opening / closing part are configured by connecting a first switch and a second switch in series, respectively. Each of the first switch and the second switch includes a diode and a switch unit connected in parallel with the diode, and the diode of the first switch and the die of the second switch And the control unit is configured to switch the storage battery that supplies power to the electric load between the first storage battery and the second storage battery when the first opening / closing unit is provided. Among the switch parts of the second opening / closing part, the switch part connected to the diode for regulating the current from the connection point side to the storage battery side is opened, and the same opening / closing part as the switch part is present. The gist is to control each of the open / close units so as to switch the storage battery during the switching intermediate state after setting the switching unit connected in series to the switch unit to a closed intermediate state.

  In the switching intermediate state in which the switch unit connected in parallel with the diode that restricts the current flow from the connection point side to the storage battery side is opened, the storage battery is switched from the storage battery side to the connection point side (that is, through the diode). The electric current is allowed to flow to the electric load), but the current is restricted to flow on the opposite side (storage battery side). For this reason, even if it switches to the state which supplies electric power to the electric load from both the storage battery sides, it can control that an electric current flows into one of the storage battery side from a connection point side by a voltage difference.

The electric circuit diagram which shows a power supply system. (A) And (b) is a figure which shows the electricity supply state in IG ON state, (c) is a figure which shows the electricity supply state at the time of a fail safe process. The flowchart which shows a switching process. The figure explaining the opening-and-closing order of a switch part. The figure explaining the opening-and-closing order of a switch part. The figure explaining the opening-and-closing order of a switch part. The figure explaining the opening-and-closing order of a switch part. The flowchart which shows the switching process of 2nd Embodiment. The electric circuit diagram which shows the power supply system of another example. The flowchart which shows the switching process of another example.

(First embodiment)
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. In the present embodiment, an in-vehicle power supply system that supplies electric power to various devices of the vehicle in a vehicle that runs using an engine (internal combustion engine) as a drive source is embodied.

  As shown in FIG. 1, this power supply system is a dual power supply system having a lead storage battery 11 as a first storage battery and a lithium ion storage battery 12 as a second storage battery. 13 and the electric load 15 can be supplied. In addition, the storage batteries 11 and 12 can be charged by the rotating electrical machine 14. In this system, the lead storage battery 11 and the lithium ion storage battery 12 are connected in parallel to the rotating electrical machine 14, and the lead storage battery 11 and the lithium ion storage battery 12 are connected in parallel to the electric load 15.

  The lead storage battery 11 is a well-known general-purpose storage battery. On the other hand, the lithium ion storage battery 12 is a high-density storage battery that has less power loss during charging / discharging than the lead storage battery 11, and has a high output density and energy density. The lithium ion storage battery 12 may be a storage battery having higher energy efficiency during charging / discharging than the lead storage battery 11. Moreover, the lithium ion storage battery 12 is comprised as an assembled battery which has a some single cell, respectively. These storage batteries 11 and 12 have the same rated voltage, for example, 12V.

  Although the detailed description by illustration is omitted, the lithium ion storage battery 12 is housed in a housing case and configured as a battery unit U integrated with a substrate. In the present embodiment, the battery unit U constitutes a “power supply device”. In FIG. 1, the battery unit U is surrounded by a broken line. The battery unit U has external terminals P0, P1, and P2. Among these, the lead storage battery 11 and the electric load 13 are connected to the external terminal P0, the rotating electrical machine 14 is connected to the external terminal P1, and the external terminal P2 is connected to the external terminal P2. An electrical load 15 is connected.

  The rotating electrical machine 14 is a generator with a motor function having a three-phase AC motor and an inverter as a power converter, and is configured as an electromechanical integrated ISG (Integrated Starter Generator). The rotating electrical machine 14 includes a power generation function that generates power (regenerative power generation) by rotating the engine output shaft and the axle, and a power running function that applies rotational force to the engine output shaft. The rotating electrical machine 14 supplies generated power to the storage batteries 11 and 12 and the electric load 15.

  The electric load 15 includes a constant voltage load in which the voltage of supplied power is required to be constant or fluctuate within a predetermined range. It can be said that the electric load 15 is a protected load. Further, it can be said that the electric load 15 is a load in which a power failure is not allowed.

  Specific examples of the electric load 15 that is a constant voltage required load include various ECUs such as a navigation device, an audio device, a meter device, and an engine ECU. In this case, by suppressing the voltage fluctuation of the supplied power, it is possible to suppress an unnecessary reset or the like in each of the above devices, and to realize a stable operation. The electric load 15 may include a travel system actuator such as an electric steering device or a brake device.

  The electric load 13 is a general electric load other than the constant voltage required load. It can be said that the electric load 13 is a load that allows a power supply failure compared to the electric load 15. Specific examples of the electric load 13 include a starter, a seat heater, a heater for a defroster for a rear window, a headlight, a wiper for a front window, a blower fan for an air conditioner, and the like.

  Next, the battery unit U will be described. The battery unit U is provided with an electrical path L1 that connects the external terminals P0 and P1 and an electrical path L2 that connects the connection point N1 on the electrical path L1 and the lithium ion storage battery 12 as an in-unit electrical path. . Among these, the switch 21 is provided in the electrical path L1, and the switch 22 is provided in the electrical path L2. The electric power generated by the rotating electrical machine 14 is supplied to the lead storage battery 11 and the lithium ion storage battery 12 through the electrical paths L1 and L2. In terms of the electrical path from the lead storage battery 11 to the lithium ion storage battery 12, a switch 21 is provided between the external terminal P0 and the connection point N1 of the rotating electrical machine 14, and the lithium ion storage battery 12 is connected to the connection point N1. A switch 22 is provided on the side.

  Further, in the battery unit U of the present embodiment, in addition to the electrical paths L1 and L2, the connection point N2 (a point between the external terminal P0 and the switch 21) on the electrical path L1 and the external terminal P2 are connected. It has a path L3. The electric path L3 forms a path that enables power supply from the lead storage battery 11 to the electric load 15. A switch 23 is provided in the electrical path L3 (specifically, between the connection point N2 and the connection point N4).

  Further, in the battery unit U, a connection point N3 (a point between the switch 22 and the lithium ion storage battery 12) of the electric path L2 and a connection point N4 (a point between the switch 23 and the external terminal P2) on the electric path L3 Are provided with an electrical path L4. A path that enables power supply from the lithium ion storage battery 12 to the electrical load 15 is formed by the electrical path L4. A switch 24 is provided in the electrical path L4 (specifically, between the connection point N3 and the connection point N4). In terms of the electrical path from the lead storage battery 11 to the lithium ion storage battery 12, a switch 23 is provided between the external terminal P0 and the connection point N4, and the switch 24 is closer to the lithium ion storage battery 12 than the connection point N4. Is provided. The switches 21 and 23 correspond to the “first opening / closing part”, and the switches 22 and 24 correspond to the “second opening / closing part”.

  Each of these switches 21-24 includes a pair of semiconductor switches 21a, 21b, 22a, 22b, 23a, 23b, 24a, 24b. The semiconductor switches 21a to 24a and 21b to 24b are MOSFETs, and are connected in series so that the parasitic diodes of the pair of MOSFETs are opposite to each other.

  For example, the switch 23 will be described in detail. The semiconductor switches 23a and 23b are connected in series. The semiconductor switches 23a and 23b inevitably have rectifying means due to their internal structure. That is, the internal circuit of the semiconductor switch 23a is a circuit in which the switch unit Sa3 and the parasitic diode Da3 are connected in parallel. Similarly, the semiconductor switch 23b is a circuit in which the switch unit Sb3 and the parasitic diode Db3 are connected in parallel. These semiconductor switches 23a and 23b are connected in series so that the parasitic diodes Da3 and Db3 are opposite to each other. The semiconductor switch 23a corresponds to the first switch, and the semiconductor switch 23b corresponds to the second switch.

  Similarly, the switch 24 is configured by connecting semiconductor switches 24a and 24b in series. The internal circuit of the semiconductor switch 24a is a circuit in which a switch unit Sa4 and a parasitic diode Da4 are connected in parallel. Similarly, the semiconductor switch 24b is a circuit in which the switch unit Sb4 and the parasitic diode Db4 are connected in parallel. These semiconductor switches 24a and 24b are connected in series so that the parasitic diodes Da4 and Db4 are opposite to each other. The semiconductor switch 24a corresponds to the first switch, and the semiconductor switch 24b corresponds to the second switch.

  For convenience, the switches 23 and 24 have been described, but the switches 21 and 22 are configured in the same manner. In FIG. 1, the parasitic diodes Da3 and Db3 are connected to each other at the anodes, but the cathodes of the parasitic diodes Da3 and Db3 may be connected to each other. The same applies to the other switches 21, 22, and 24.

  By configuring the switches 21 to 24 as described above, for example, when the switch 23 is turned off, that is, when the semiconductor switches 23a and 23b are turned off, a current flows through the parasitic diodes Da3 and Db3. Is completely blocked.

  In addition, it is also possible to use IGBT, a bipolar transistor, etc. instead of MOSFET as semiconductor switch 21a-24a, 21b-24b. When an IGBT or a bipolar transistor is used as a switch unit, a diode that is a substitute for the parasitic diode may be connected to the switch unit in parallel. Moreover, in the switches 21 to 24, a plurality of sets of MOSFETs may be provided, and a plurality of sets of MOSFETs may be connected in parallel.

  Further, the battery unit U is provided with bypass paths B1 and B2 that allow the lead storage battery 11 to be connected to the rotating electrical machine 14 and the electric load 15 without using the switches 21 and 23 in the unit. That is, the bypass paths B1 and B2 are provided so as to bypass the switches 21 and 23 on the electric paths L1 and L3.

  One end of the bypass path B1 is connected to the connection point N2 on the electric path L1 inside the unit, and the other end is connected to the connection point N1 on the electric path L1 inside the unit. The bypass route B1 is provided with a bypass opening / closing circuit RE1 for energizing or shutting off the bypass route B1. The bypass opening / closing circuit RE1 has, for example, a normally closed mechanical relay. If the bypass path B1 is energized by the bypass switching circuit RE1, supply of generated power from the rotating electrical machine 14 to the lead storage battery 11 via the bypass path B1 even when the switch 21 is turned off. Is possible.

  One end of the bypass path B2 is connected to a connection point N2 on the electric path L1 inside the unit, and the other end is connected to a connection point N4 on the electric path L3 inside the unit. The bypass path B2 is provided with a bypass opening / closing circuit RE2 for energizing or interrupting the bypass path B2. The bypass switching circuit RE2 has, for example, a normally closed mechanical relay. If the bypass path B2 is energized by the bypass switching circuit RE2, the power supply from the lead storage battery 11 to the electric load 15 can be performed via the bypass path B2 even when the switch 23 is turned off. It is possible.

  The battery unit U is provided with a voltage detector 31 for detecting the voltage value on the lead storage battery 11 side and a voltage detector 32 for detecting the voltage value on the lithium ion storage battery 12 side. More specifically, the voltage detector 31 that detects the voltage value on the lead storage battery 11 side detects the voltage value at a point (for example, the external terminal P0) on the lead storage battery 11 side of the switch 23 in the electrical path L3. The voltage detector 32 that detects the voltage value on the lithium ion storage battery 12 side detects the voltage value at a point (for example, the connection point N3) on the lithium ion storage battery 12 side of the switch 24 in the electrical path L4.

  The external terminal P0 is connected to the lead storage battery 11 via the fuse 35. The external terminal P2 is connected to the electrical load 15 via the fuse 38. Further, the connection point N2 is connected to the bypass switching circuit RE1 through the fuse 37.

  The battery unit U includes a control unit 51 that controls the switches 21 to 24 and the bypass switching circuits RE1 and RE2. The control unit 51 is configured by a microcomputer including a CPU, ROM, RAM, input / output interface, and the like.

  The control unit 51 controls the switches 21 to 24 and the like based on the storage state of the storage batteries 11 and 12 and the like. For example, the control unit 51 controls the bypass opening / closing circuits RE1 and RE2 to be closed and the switches 21 to 24 to be opened while the in-vehicle power supply system is stopped (that is, the ignition switch is off). Hereinafter, the stop state of the in-vehicle power supply system is referred to as an IG off state. In addition, an operating state of the in-vehicle power supply system (that is, an ignition switch on state) is indicated as an IG on state.

  On the other hand, in the IG-on state, the control unit 51 opens the bypass opening / closing circuits RE1 and RE2 and controls the switches 21 to 24 to open and close as appropriate. In that case, the control part 51 controls each switch 21-24 suitably so that at least one of the switch 23 or the switch 24 may close. That is, the control unit 51 appropriately controls each of the switches 21 to 24 so that power is continuously supplied to the electric load 15.

  Specifically, the control unit 51 calculates the SOC (remaining capacity: State Of Charge) of the lithium ion storage battery 12. And the control part 51 controls each switch 21-24 so that the SOC may be maintained in a predetermined use range, and controls charge and discharge of the lead storage battery 11 and the lithium ion storage battery 12. That is, the control unit 51 performs charging / discharging by selectively using the lead storage battery 11 and the lithium ion storage battery 12.

  In addition, the control unit 51 performs abnormality determination related to the battery unit U. Examples of the abnormality relating to the battery unit U include an abnormality relating to charging / discharging of the lithium ion storage battery 12 and an abnormality relating to each of the switches 21 to 24. And the control part 51 implements control which closes bypass bypass circuit RE1, RE2 while forcibly opening each switch 21-24 as a fail safe process at the time of abnormality determination.

  For example, the control unit 51 uses a current sensor or a temperature sensor to detect that an overcurrent is flowing in the lithium ion storage battery 12 or that the temperature of the lithium ion storage battery 12 is excessively increased. Implement fail-safe processing. Thereby, the control part 51 functions also as an abnormality determination part which determines abnormality (failure) of a vehicle-mounted power supply system.

  The control unit 51 is connected to an ECU 52 made of, for example, an engine ECU. The ECU 52 is composed of a microcomputer including a CPU, ROM, RAM, input / output interface, and the like, and controls the operation of the engine based on the engine operating state and the vehicle traveling state each time. The control unit 51 and the ECU 52 are connected by a communication network such as CAN and can communicate with each other, and various data stored in the control unit 51 and the ECU 52 can be shared with each other. The ECU 52 may detect an abnormality (failure) in the in-vehicle power supply system, and the ECU 52 may notify the control unit 51 of the failure (abnormality). When an abnormality is notified from the ECU 52, the control unit 51 performs various processes as a fail-safe process.

  Next, the state of the battery unit U in the IG on state will be described. In the IG ON state, for example, as shown in FIG. 2A, the switches 21 and 23 may be closed, the switches 22 and 24 may be opened, and the bypass opening / closing circuits RE1 and RE2 may be open. If power generation of the rotating electrical machine 14 is performed in such a state, the generated power is supplied to the lead storage battery 11 and the generated power is supplied to the electric load 15. Even if power generation is not performed, electric power is supplied from the lead storage battery 11 to the electric load 15.

  In the IG ON state, for example, as shown in FIG. 2B, the switches 22 and 24 are closed, the switches 21 and 23 are opened, and the bypass switching circuits RE1 and RE2 are opened. is there. If the rotating electrical machine 14 generates power in such a state, the generated power is supplied to the lithium ion storage battery 12 and the generated power is supplied to the electric load 15. Further, even if power generation is not performed, power is supplied from the lithium ion storage battery 12 to the electric load 15.

  In the IG on state, the switches 21 to 24 are appropriately controlled so that at least one of the switch 23 and the switch 24 is turned on (closed). For this reason, it is possible to supply power to the electrical load 15 from at least one of the lead storage battery 11 and the lithium ion storage battery 12.

  Next, the state of the battery unit U during the fail safe state will be described. In the fail-safe state, as shown in FIG. 2C, the switches 21 to 24 are open, and the bypass switching circuits RE1 and RE2 are closed. If power generation of the rotating electrical machine 14 is performed in such a state, the generated power is supplied to the lead storage battery 11 and the generated power is supplied to the electric load 15. Even if power generation is not performed, electric power is supplied from the lead storage battery 11 to the electric load 15.

  By the way, the electric load 15 includes a constant voltage load. For this reason, when switching the storage batteries 11 and 12 which supply electric power to the electric load 15 between the lead storage battery 11 and the lithium ion storage battery 12, it is necessary to prevent a power defect from occurring. That is, when switching between the switch 23 and the switch 24, after temporarily setting the power to be supplied from both the storage batteries 11 and 12, by opening one of the switches 23 and 24, a power defect occurs. It is necessary not to.

  However, when power is temporarily supplied from both the storage batteries 11 and 12, an unintended overcurrent may flow through the switch 23 and the switch 24 depending on the voltage difference between the storage batteries 11 and 12. That is, when the electric paths L3 and L4 are both energized, the switch 23 and the switch 24 are used to switch from one storage battery 11 or 12 having a high voltage value to the other storage battery 11 or 12 having a low voltage value. An overcurrent may flow between the storage batteries 11 and 12.

  As shown in FIG. 1, the lead storage battery 11 is connected to an electrical load 13 that temporarily supplies power. When electric power is requested from the electric load 13, the voltage value on the lead storage battery 11 side that supplies electric power to the electric load 13 may be lower than that on the lithium ion storage battery 12 side. That is, the voltage value at the external terminal P0 to which the lead storage battery 11 is connected may be lower than the voltage value of the lithium ion storage battery 12. In this case as well, an overcurrent may flow from the lithium ion storage battery 12 side having a high voltage value to the lead storage battery 11 side having a low voltage value via the switch 23 and the switch 24.

  Moreover, as shown in FIG. 1, the lead storage battery 11 and the lithium ion storage battery 12 are connected to the rotating electrical machine 14 via electrical paths L1 and L2, respectively. When one of the electric paths L1 and L2 is energized and the generated electric power is supplied from the rotating electrical machine 14, the voltage value on the side of the storage batteries 11 and 12 to which the generated electric power is supplied is supplied. Compared to the voltage value on the storage battery 11, 12 side, there is a possibility that it becomes higher.

  That is, when the generated power is supplied from the rotating electrical machine 14 to the lead storage battery 11 via the electrical path L1 (for example, the state of FIG. 2A), the voltage value at the external terminal P0 to which the lead storage battery 11 is connected is The voltage value of the lithium ion storage battery 12 may be higher. In this case, when both the electrical paths L3 and L4 are energized, the lead storage battery 11 side (that is, the external voltage) having a high voltage value is connected via the switch 23 and the switch 24 even when the electrical path L2 is in the energized state. There is a possibility that an overcurrent flows from the terminal P0 side) to the lithium ion storage battery 12 side having a low voltage value (that is, the connection point N3 side).

  In addition, when generated power is supplied from the rotating electrical machine 14 to the lithium ion storage battery 12 via the electrical path L2 (for example, the state of FIG. 2B), the voltage at the connection point N3 to which the lithium ion storage battery 12 is connected. The value may be higher than the voltage value of the lead storage battery 11. In this case, if both the electrical paths L3 and L4 are energized, the lithium ion storage battery 12 side with a high voltage value (that is, the side of the lithium ion storage battery 12 through the switch 23 and the switch 24) There is a possibility that an overcurrent flows from the connection point N3 side) to the lead storage battery 11 side having a low voltage value (that is, the external terminal P0 side).

  In these cases, an excessive current may flow through the switch 23 and the switch 24 with respect to the allowable current amount. At this time, the switch 23 or the switch 24 may have some abnormality.

  In general, the rotating electrical machine 14 adjusts the power generation amount so as to be a constant voltage. For this reason, when a current flows into the storage batteries 11 and 12 having a low voltage value (not to be charged) through the switches 23 and 24, the rotating electrical machine 14 can increase the amount of power generation to maintain the voltage. There is sex. In this case, a larger current may flow through the switch 23 and the switch 24.

  Therefore, when switching on and off of the switches 23 and 24 is performed, overcurrent flows from the connection point N4 side to the storage batteries 11 and 12 side through the switch 23 and the switch 24 by performing predetermined control. . This will be described in detail below.

  Control part 51 acquires the voltage value by the side of lead storage battery 11, and the voltage value by the side of lithium ion storage battery 12, when it is required (determination) to switch on and off of switches 23 and 24 mutually. Specifically, the control unit 51 is connected to the voltage detectors 31 and 32, and acquires voltage values from the voltage detectors 31 and 32, respectively.

  The control unit 51 compares the voltage value on the lead storage battery 11 side with the voltage value on the lithium ion storage battery 12 side. And the control part 51 specifies the switch part by the side of a storage battery with a low voltage value among switch part Sa3, Sa4, Sb3, Sb4 which switch 23,24 has. Then, the control unit 51 opens (opens) the switch unit that is connected in parallel with the parasitic diode that allows the current to the connection point N4 side and regulates the current to the opposite side among the identified switch units. State). At the same time, the control unit 51 causes the other switch unit among the identified switch units to be in a closed state (closed state). That is, the control unit 51 restricts the current to the connection point N4 side among the identified switch units and closes the switch unit connected in parallel with the parasitic diode that allows the current to the opposite side. . This state is referred to as a switching intermediate state.

  For example, when the lead storage battery 11 side is low, the current from the storage battery side having a low voltage value to the connection point N4 side is the current from the lead storage battery 11 side, specifically, the external terminal P0 (or connection point N2). To the connection point N4 (or the external terminal P2). In this case, the control part 51 specifies switch part Sa3, Sb3 as a switch part by the side of the lead storage battery 11 with a low voltage value. And the control part 51 opens the switch part Sb3 connected in parallel with the parasitic diode Db3 which regulates the electric current to the lead storage battery 11 side among the specified switch parts Sa3 and Sb3, and the switch part Sa3. Let it be closed.

  On the other hand, when the lithium ion storage battery 12 side is low, the current from the storage battery side having a low voltage value to the connection point N4 side is the current from the lithium ion storage battery 12 side, specifically, the connection point N3 to the connection point N4. (Or current to the external terminal P2). In this case, the control part 51 specifies switch part Sa4, Sb4 as a switch part by the side of the lithium ion storage battery 12 with a low voltage value. And the control part 51 makes the switch part Sa4 connected in parallel with the parasitic diode Da4 which regulates the electric current to the lithium ion storage battery 12 side among the specified switch parts Sa4 and Sb4 open, and the switch part Sb4. Is closed.

  In this switching intermediate state, the control unit 51 closes all of the switch units on the storage battery side having a high voltage value among the switch units Sa3, Sa4, Sb3, and Sb4 included in the switches 23 and 24. Thereby, electric power will be supplied with respect to the electric load 15 from either storage battery 11 and 12 side.

  On the other hand, in the switching intermediate state, among the switch units on the storage battery side having a low voltage value, the switch unit connected in parallel with the parasitic diode that regulates the current to the connection point N4 side is opened. For this reason, even if the voltage difference of the storage batteries 11 and 12 is large, it is controlled that an electric current flows from the connection point N4 side to the storage battery side with a low voltage value.

  After entering the switching intermediate state, the control unit 51 identifies the switches 23 and 24 that are requested (determined) to be opened by the switching request among the switches 23 and 24, and opens all the switch units of the switch. Let That is, the control part 51 specifies the switch provided in the electrical path | route made into an electric conduction interruption state among the electrical paths L3 and L4, and opens the switch part of the said switch. Thereby, among the electric paths L3 and L4, the electric path between the storage battery that does not supply electric power to the electric load 15 is in a state where the energization is cut off. As described above, the storage batteries 11 and 12 that supply power to the electric load 15 are switched.

  When the switch on the storage battery side having a low voltage value is a switch to be closed, the switch on the storage battery side having a high voltage value is opened, and then the switch on the storage battery side having a low voltage value is closed. That is, the switching intermediate state is terminated.

  As described above, when the switches 23 and 24 are switched on and off, current flows from the connection point N4 side to the storage battery having a low voltage value via the switches 23 and 24 while continuing to supply power to the electric load 15. Can be regulated. That is, it is possible to restrict the flow of current from the external terminal P0 to the connection point N3 and the flow of current from the connection point N3 to the external terminal P0 through the electrical paths L3 and L4.

  Incidentally, when fail-safe processing is performed, the control unit 51 closes the switch 23 and opens the switch 24, then closes the bypass opening / closing circuit RE2, and then opens the switch 23. Yes. As a result, it is possible to avoid a situation in which the bypass switching circuit RE2 and the switch 24 are simultaneously closed. That is, when the bypass switching circuit RE2 and the switch 24 are closed at the same time, a current may flow from the connection point N4 side to either storage battery side via the bypass switching circuit RE2 and the switch 24 due to the potential difference between the storage batteries 11 and 12. There is sex. For this reason, the switch 23 is closed, the switch 24 is opened, and then the bypass switching circuit RE2 is closed to prevent a current from flowing to any one of the storage batteries.

  Next, a switching process executed when the switches 23 and 24 are switched on and off will be described with reference to FIG. The switching process is executed by the control unit 51 at predetermined intervals.

  The control unit 51 determines whether or not a switching request has occurred (step S101). The switching request (decision to switch the switches 23 and 24) is generated based on the processing result of the control unit 51 and a command from the ECU 52. For example, the control unit 51 may make a switching request based on the charging status of the storage batteries 11 and 12. Further, the ECU 52 may make a switching request depending on the power generation status of the rotating electrical machine 14, power running drive, power demand from the electrical load 13, and the like. In addition, a switching request may occur in fail-safe processing. When the switching request has not occurred (step S101: NO), the control unit 51 ends the switching process.

  When the switching request has occurred (step S101: YES), the control unit 51 compares the voltage values of the storage batteries 11 and 12 acquired from the voltage detectors 31 and 32, and the voltage value (Pb) on the lead storage battery 11 side. It is determined whether or not (voltage) is higher than the voltage value (Li voltage) on the lithium ion storage battery 12 side (step S102).

  When the voltage value on the lead storage battery 11 side is higher (step S102: YES), the control unit 51 is a switching request for opening the closed switch 23 and closing the opened switch 24. Is determined (step S103). Which switch 23, 24 is to be opened or closed is specified based on the processing result of the control unit 51 and the content of a command from the ECU 52. For example, when the charge amount of one of the storage batteries 11 and 12 decreases, a switching request for specifying opening and closing of the switches 23 and 24 is performed so that power is supplied from the other storage battery 11 and 12 to the electric load 15. . In addition, when an abnormality occurs, a switching request is made to specify opening and closing of the switches 23 and 24 so that electric power is supplied from the lead storage battery 11.

  When it is the switching request | requirement which opens the switch 23 (step S103: YES), the control part 51 closes switch part Sb4 of the switch 24 (step S104). That is, when the voltage value on the lithium ion storage battery 12 side is low, the control unit 51 causes the switch unit Sa4 to be in the open state and the switch unit Sb4 to be in the closed state (in order to switch to the switching intermediate state). To close.

  After a predetermined time (for example, 100 ms) has elapsed from step S104, the control unit 51 opens the switch units Sa3 and Sb3 of the switch 23 that is requested (determined) to be opened (step S105). Moreover, the control part 51 closes switch part Sa4 (step S106), and complete | finishes a switching process. The switching intermediate state is also ended by closing the switch part Sa4.

  If it is not a switching request to open the switch 23 (step S103: NO), that is, if it is a switching request to close the opened switch 23, the control unit 51 opens the switch unit Sa4 of the switch 24 (step S107). ). When the voltage value of the lead storage battery 11 is higher, that is, when the voltage value on the lithium ion storage battery 12 side is low, the switch part Sa4 is opened and the switch part Sb4 is closed (in the switching intermediate state). Switch part Sa4 is opened.

  After a predetermined time has elapsed from step S107, the control unit 51 closes the switch units Sa3 and Sb3 of the switch 23 (step S108). That is, in step S108, the control unit 51 closes all the switch units Sa3 and Sb3 on the lead storage battery 11 side having a high voltage value. The control unit 51 opens the switch unit Sb4 of the switch 24 that is requested (determined) to be opened (step S109), and ends the switching process.

  When the voltage value on the lead storage battery 11 side is lower (step S102: NO), the control unit 51 is a switching request for opening the closed switch 23 and closing the opened switch 24. Is determined (step S110).

  When it is a switching request for opening the closed switch 23 (step S110: YES), the control unit 51 opens the switch unit Sb3 of the switch 23 (step S111). When the voltage value on the lead storage battery 11 side is lower, the control unit 51 causes the switch unit Sb3 to be in the open state and the switch unit Sa3 to be in the closed state (in order to switch to the switching intermediate state). Open.

  After a predetermined time has elapsed from step S111, the control unit 51 closes the switch units Sa4 and Sb4 of the switch 24 (step S112). That is, in step S112, the control unit 51 closes all the switch units Sa4 and Sb4 on the lithium ion storage battery 12 side having a high voltage value. Thereafter, the control unit 51 opens the switch unit Sa3 of the switch 23 that is requested (determined) to be opened (step S113), and ends the switching process.

  When it is not a switching request for opening the closed switch 23 (step S110: NO), that is, when it is a switching request for closing the opened switch 23, the control unit 51 closes the switch unit Sa3 of the switch 23. (Step S114). When the voltage value on the lead storage battery 11 side is lower, the control unit 51 causes the switch unit Sb3 to be in an open state and the switch unit Sa3 to be in a closed state (in order to switch to a switching intermediate state). Close.

  After a predetermined time has elapsed from step S114, the control unit 51 opens the switch units Sa4 and Sb4 of the switch 24 that is requested (determined) to be opened (step S115). Then, the control part 51 closes switch part Sb3 (step S116), and complete | finishes a switching process. Note that the switching intermediate state is also ended by closing the switch unit Sb3.

  By performing the above switching process, when the switches 23 and 24 are switched on and off, the current from the storage batteries 11 and 12 to the connection point N4 is allowed, so that the power supply to the electric load 15 is continued. Will be. On the other hand, the current from the connection point N4 side to the storage battery having the lower voltage value among the storage batteries 11 and 12 is regulated. That is, of the storage batteries 11 and 12, the current from the storage battery side having a high voltage value to the storage battery side having a low voltage value is regulated.

  Next, based on FIGS. 4-7, the switching order of each switch part Sa3, Sb3, Sa4, Sb4 in the case of switching the storage batteries 11 and 12 which supply the electric power to the electric load 15 is demonstrated. 4 to 7, only the electric paths L3 and L4, the switches 23 and 24, the storage batteries 11 and 12, and the electric load 15 are illustrated to simplify the configuration of the in-vehicle power supply system.

  First, a case where the voltage value on the lead storage battery 11 side is higher and the switch 23 is changed from the closed state to the open state will be described with reference to FIG. That is, the case where the storage batteries 11 and 12 that supply power to the electric load 15 are switched from the lead storage battery 11 to the lithium ion storage battery 12 when the voltage value on the lead storage battery 11 side is higher will be described.

  As shown in FIG. 4A, in the initial state, the switch portions Sa3 and Sb3 of the switch 23 are closed (ON), and the switch portions Sa4 and Sb4 of the switch 24 are opened (OFF). Thereby, in an initial state, a current flows from the lead storage battery 11 side to the connection point N4 side, and power is supplied from the lead storage battery 11 side to the electric load 15. On the other hand, no current flows from the lithium ion storage battery 12 side to the connection point N4 side.

  When the switching request is generated, step S104 of the switching process is performed, and the switch unit Sb4 is first closed as shown in FIG. 4B. Thereby, a current flows from the lead storage battery 11 and the lithium ion storage battery 12 side to the connection point N4 side, and power is supplied to the electric load 15 from both storage batteries 11 and 12 side. Even if the voltage value on the lead storage battery 11 side is higher than the voltage value on the lithium ion storage battery 12 side, since the switch part Sa4 is opened, no current flows from the connection point N4 side to the lithium ion storage battery 12 side. . That is, current does not flow from the lead storage battery 11 side to the lithium ion storage battery 12 side via the electrical paths L3 and L4.

  Thereafter, step S105 of the switching process is performed, and the switch parts Sa3 and Sb3 are opened as shown in FIG. As a result, the electric path L3 is in a state where the energization is cut off, and power is not supplied from the lead storage battery 11 side to the electric load 15, and no current flows from the connection point N4 side to the lead storage battery 11 side. On the other hand, since the switch unit Sb4 is in a closed state, a current flows from the lithium ion storage battery 12 side to the connection point N4 side via the switch unit Sb4 and the parasitic diode Da4. Thereby, electric power is continuously supplied from the lithium ion storage battery 12 side to the electric load 15.

  Then, step S106 of the switching process is performed, and the switch unit Sa4 is closed as shown in FIG. As a result, the electrical path L4 is energized, and the switching of the switches 23 and 24 is completed.

  Next, a case where the voltage value on the lead storage battery 11 side is higher and the switch 23 is changed from the open state to the closed state will be described with reference to FIG. That is, the case where the storage batteries 11 and 12 that supply power to the electric load 15 are switched from the lithium ion storage battery 12 to the lead storage battery 11 when the voltage value on the lead storage battery 11 side is higher will be described.

  As shown in FIG. 5A, in the initial state, the switch portions Sa3 and Sb3 of the switch 23 are opened (OFF), and the switch portions Sa4 and Sb4 of the switch 24 are closed (ON). Thereby, in an initial state, a current flows from the lithium ion storage battery 12 side to the connection point N4 side, and power is supplied from the lithium ion storage battery 12 side to the electric load 15. On the other hand, no current flows from the lead storage battery 11 side to the connection point N4 side.

  When a switching request is generated, step S107 of the switching process is performed, and the switch unit Sa4 is first opened as shown in FIG. Also in this case, since the switch part Sb4 is in a closed state, a current flows from the lithium ion storage battery 12 side to the connection point N4 side via the switch part Sb4 and the parasitic diode Da4. That is, electric power is continuously supplied from the lithium ion storage battery 12 side to the electric load 15.

  Thereafter, step S108 of the switching process is performed, and the switch parts Sa3 and Sb3 are closed as shown in FIG. Thereby, a current flows from the lead storage battery 11 and the lithium ion storage battery 12 side to the connection point N4 side, and power is supplied to the electric load 15 from both storage batteries 11 and 12 side. On the other hand, even if the voltage value on the lead storage battery 11 side is higher than the voltage value on the lithium ion storage battery 12 side, since the switch part Sa4 is open, a current flows from the connection point N4 side to the lithium ion storage battery 12 side. There is no.

  Thereafter, step S109 of the switching process is performed, and the switch unit Sb4 is opened as shown in FIG. As a result, the electrical path L3 is energized, while the electrical path L4 is energized and the switching of the switches 23 and 24 is completed.

  Next, a case where the voltage value on the lithium ion storage battery 12 side is higher and the switch 23 is changed from the closed state to the open state will be described with reference to FIG. That is, the case where the storage batteries 11 and 12 that supply power to the electric load 15 are switched from the lead storage battery 11 to the lithium ion storage battery 12 when the voltage value on the lithium ion storage battery 12 side is higher will be described.

  As shown in FIG. 6A, in the initial state, the switch portions Sa3 and Sb3 of the switch 23 are closed (ON), and the switch portions Sa4 and Sb4 of the switch 24 are opened (OFF). Thereby, in an initial state, a current flows from the lead storage battery 11 side to the connection point N4 side, and power is supplied from the lead storage battery 11 side to the electric load 15. On the other hand, no current flows from the lithium ion storage battery 12 side to the connection point N4 side.

  When the switching request is generated, step S111 of the switching process is performed, and as shown in FIG. 6B, the switch unit Sb3 is first opened. Also in this case, since the switch part Sa3 is in the closed state, a current flows from the lead storage battery 11 side to the connection point N4 side via the switch part Sa3 and the parasitic diode Db3. That is, electric power is continuously supplied from the lead storage battery 11 side to the electric load 15.

  Thereafter, step S112 of the switching process is performed, and the switch parts Sa4 and Sb4 are closed as shown in FIG. Thereby, a current flows from the lead storage battery 11 and the lithium ion storage battery 12 side to the connection point N4 side, and power is supplied to the electric load 15 from both storage batteries 11 and 12 side. On the other hand, even if the voltage value on the lithium ion storage battery 12 side is higher than the voltage value on the lead storage battery 11 side, the current flows from the connection point N4 side to the lead storage battery 11 side because the switch portion Sb3 is open. Absent.

  Thereafter, step S113 of the switching process is performed, and the switch unit Sa3 is opened as shown in FIG. As a result, the electrical path L3 is energized, while the electrical path L4 is energized and the switching of the switches 23 and 24 is completed.

  Next, a case where the voltage value on the lithium ion storage battery 12 side is higher and the switch 23 is changed from the open state to the closed state will be described with reference to FIG. That is, the case where the storage batteries 11 and 12 that supply power to the electric load 15 are switched from the lithium ion storage battery 12 to the lead storage battery 11 when the voltage value on the lithium ion storage battery 12 side is higher will be described.

  As shown in FIG. 7A, in the initial state, the switch portions Sa3 and Sb3 of the switch 23 are opened (OFF), and the switch portions Sa4 and Sb4 of the switch 24 are closed (ON). Thereby, in an initial state, a current flows from the lithium ion storage battery 12 side to the connection point N4 side, and power is supplied from the lithium ion storage battery 12 side to the electric load 15. On the other hand, no current flows from the lead storage battery 11 side to the connection point N4 side.

  When the switching request is generated, step S114 of the switching process is performed, and the switch unit Sa3 is first closed as shown in FIG. 7B. Thereby, a current flows from the lead storage battery 11 and the lithium ion storage battery 12 side to the connection point N4 side, and power is supplied to the electric load 15 from both storage batteries 11 and 12 side. Even if the voltage value on the lithium ion storage battery 12 side is higher than the voltage value on the lead storage battery 11 side, since the switch part Sb3 as a specific switch part is opened, the current from the connection point N4 side to the lead storage battery 11 side Will not flow. That is, no current flows from the lithium ion storage battery 12 side to the lead storage battery 11 side via the electrical paths L3 and L4.

  Thereafter, step S115 of the switching process is performed, and the switch parts Sa4 and Sb4 are opened as shown in FIG. As a result, the electrical path L4 is turned off, and power is not supplied from the lithium ion storage battery 12 side to the electrical load 15, and no current flows from the connection point N4 side to the lithium ion storage battery 12 side. On the other hand, since the switch part Sa3 is in a closed state, a current flows from the lead storage battery 11 side to the connection point N4 side via the switch part Sa3 and the parasitic diode Db3. Thereby, electric power is continuously supplied from the lead storage battery 11 side to the electric load 15.

  Then, step S116 of the switching process is performed, and the switch unit Sb3 is closed as shown in FIG. As a result, the electrical path L3 is energized, and the switching of the switches 23 and 24 is completed.

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

  The storage batteries 11 and 12 are switched through a switching intermediate state in which the switch portions Sb3 and Sa4 connected in parallel with the parasitic diodes Db3 and Da4 that restrict the current flow from the connection point N4 side to the storage batteries 11 and 12 side are opened. . In this switching intermediate state, current is allowed to flow from the storage batteries 11 and 12 side to the connection point N4 side via the parasitic diodes Db3 and Da4, but current is passed to the opposite side (storage batteries 11 and 12 side). Flow is regulated. For this reason, even if the other switch parts other than the switch parts Sb3 and Sa4 are closed and power is supplied to the electric load 15 from both the storage batteries 11 and 12, the voltage difference between the storage batteries 11 and 12 It is possible to regulate the current flowing to the storage battery side. As a result, when the switches 23 and 24 are switched, it is possible to restrict the flow of an excessive current that exceeds the allowable current amount of each of the switch portions Sa3, Sb3, Sa4, and Sb4, thereby protecting the switches 23 and 24.

  When the electric paths L3 and L4 are both energized, when there is a voltage difference between the storage batteries 11 and 12, a current flows from the connection point N4 side to the storage battery side having a low voltage value via the switches 23 and 24. On the other hand, no current flows from the connection point N4 side to the storage batteries 11 and 12 side having a high voltage value.

  For this reason, in the switching intermediate state, the switch part connected in parallel with the parasitic diode that regulates the current from the connection point N4 side to the storage battery side having a low voltage value is opened, and the other switch parts are closed. It was decided to be in a state. As a result, an excessive current flows from the connection point N4 side to the storage batteries 11 and 12 to the switches 23 and 24 provided on the electric paths L3 and L4 between the electric load 15 and the storage batteries 11 and 12 having a low voltage value. Flow can be regulated. Therefore, the switches 23 and 24 that need to be protected can be appropriately protected.

  In addition, no current flows from the connection point N4 side to the storage batteries 11 and 12 side having a high voltage value. That is, it is not necessary to open the switch unit provided on the side of the storage battery having a high voltage value. For this reason, by comparing the voltage value, by opening the switch unit connected in parallel with the parasitic diode that regulates the current to the storage battery side having a low voltage value, the switch unit that does not need to be opened is determined. It can be prevented from opening.

  A lead storage battery 11 and an electrical load 13 are connected in parallel to the external terminal P0. When electric power is temporarily supplied from the electrical load 13, the voltage value on the lead storage battery 11 side may be temporarily reduced. That is, the voltage value at the external terminal P0 may be lower than that of the lithium ion storage battery 12 due to the influence of the electric load 13. In this case, if the electrical paths L3 and L4 are both energized and the switches 23 and 24 are switched, an excessive current may flow with respect to the allowable current amount of the switches 23 and 24 due to the power demand of the electrical load 13. There is. In particular, if the power demand of the electric load 13 is large, the possibility increases.

  However, even if the switches 23 and 24 are switched when power is requested from the electrical load 13 by executing the switching process as described above, the current is supplied to the lead storage battery 11 side through the switches 23 and 24. Can be controlled. That is, regardless of the power demand from the electric load 13, the switch portions Sa3, Sb3, Sa4, and Sb4 can be appropriately opened and closed.

  A lead storage battery 11 and a lithium ion storage battery 12 are connected in parallel to the rotating electrical machine 14 via electrical paths L1 and L2. For this reason, when electric power is supplied from the rotating electrical machine 14, the voltage value on the storage battery 11, 12 side may also temporarily increase. However, even if the switches 23 and 24 are switched when the electric power is supplied from the rotating electrical machine 14 by executing the switching process as described above, the connection point N4 is connected via the switches 23 and 24. It can control that an electric current flows into either storage battery 11 and 12 side. That is, each switch part Sa3, Sb3, Sa4, Sb4 can be appropriately opened and closed irrespective of the situation of the rotating electrical machine 14 and the opening and closing situation of the switches 21 and 22. For this reason, control becomes easy.

  A rotating electrical machine 14 or an electric load 13 as a power supply source other than the storage batteries 11 and 12 is connected to each of the storage batteries 11 and 12, and the storage batteries 11 and 12 are connected even if there is a power supply or a power request from them. When switching, current does not flow from the connection point N4 side to the storage battery side having a low voltage. That is, each switch part Sa3, Sb3, Sa4, Sb4 can be opened and closed without considering the situation of the rotating electrical machine 14 and the electrical load 13. Therefore, by executing this switching process, the switches 23 and 24 can be switched quickly and appropriately at the time of abnormality determination.

  The control unit 51 opens the switch unit connected in parallel with the parasitic diode that allows the current to the connection point N4 and regulates the current to the opposite side among the switch units on the storage battery side having a low voltage value. After making it into a state, other switch parts are made into a closed state. Thereby, even if it is a case where the storage batteries 11 and 12 which supply electric power to the electric load 15 are switched, electric power can be continued to be supplied to the electric load 15. Therefore, the electric load 15 can include a constant voltage load that requires constant voltage power.

(Second Embodiment)
In 2nd Embodiment, after making all the switch parts Sb3 and Sa4 into an open state, the control part 51 closes the switch part by the side of a storage battery with a high voltage value among switch parts Sb3 and Sa4, In that state, The switches 23 and 24 are switched.

  That is, at the time of the switching request of the switches 23 and 24, the control unit 51 opens all the switch units Sb3 and Sa4 and sets all the other switch units Sa3 and Sb4 regardless of the voltage difference between the storage batteries 11 and 12. Closed state (switching intermediate state). Based on the current or potential difference between the switches 23 and 24, the control unit 51 identifies the storage battery side having a high voltage value and closes the switch on the storage battery side having a high voltage value. Then, the control part 51 opens the switch part provided in the electric paths L3 and L4 to be in a state where the energization is cut off. At that time, among the switch portions Sb3 and Sa4, the switch portions provided in the electric paths L3 and L4 to be energized are closed. Hereinafter, the switching process will be described in detail with reference to FIG.

  The control unit 51 determines whether or not a switching request has occurred (step S301). When the switching request has not occurred (step S301: NO), the control unit 51 ends the switching process. When the switching request has occurred (step S301: YES), the control unit 51 determines whether or not the switching request is to open the closed switch 23 (step S302).

  When it is a switching request for opening the switch 23 (step S302: YES), the control unit 51 opens the switch unit Sb3 of the switch 23 (step S303). Moreover, the control part 51 closes switch part Sb4 of the switch 24 (step S304). That is, the control unit 51 closes the switch unit Sb4 in order to open the switch units Sb3 and Sa4 and to close the switch units Sa3 and Sb4 (in order to make the switch intermediate state).

  Thereafter, the current flowing through the switches 23 and 24 is acquired (step S305). Each of the switches 23 and 24 is provided with a current detection circuit (not shown) as a detection unit for detecting the current flowing through the switches 23 and 24, and the control unit 51 receives the switches 23 and 24 from each current detection circuit. Current for each.

  Then, the control unit 51 determines whether or not the current flowing through the switch 23 is larger than the current flowing through the switch 24 (step S306). That is, based on the ratio of the current supplied to the electric load 15, the storage battery side having a higher voltage value is determined among the storage batteries 11 and 12. Although the currents of the switches 23 and 24 are detected and compared, the voltage values of the storage batteries 11 and 12 may be detected and compared. Further, the currents flowing through the parasitic diodes Db3 and Da4 may be detected and compared.

  When the current flowing through the switch 23 is larger (step S306: YES), the control unit 51 closes the switch unit Sb3 (step S307). That is, since the lead storage battery 11 side has a higher voltage value than the lithium ion storage battery 12 side, the control unit 51 closes the switch unit Sb3. Thereby, it can suppress that a big electric current continues flowing into the parasitic diode Db3.

  Then, the control unit 51 opens the switch units Sa3 and Sb3 of the switch 23 that is requested (determined) to be opened (step S308). The control unit 51 closes the switch unit Sa4 (step S309) and ends the switching process.

  When the current flowing through the switch 24 is larger (step S306: No), the control unit 51 closes the switch unit Sa4 (step S310). That is, since the lead storage battery 11 side has a lower voltage value than the lithium ion storage battery 12 side, the control unit 51 closes the switch unit Sa4. Thereby, it can suppress that a big electric current continues flowing into the parasitic diode Da4.

  Then, the control unit 51 opens the switch unit Sa3 of the switch 23 that is requested (determined) to be opened (step S311), and ends the switching process.

  When the switch request is not for opening the switch 23 (step S302: NO), the control unit 51 opens the switch unit Sa4 of the switch 24 (step S312). The control unit 51 closes the switch unit Sa3 of the switch 23 (step S313). In other words, the control unit 51 closes the switch unit Sa3 in order to open the switch units Sb3 and Sa4 and to close the switch units Sa3 and Sb4 (in order to set the switch units Sa3 and Sb4 to the switching intermediate state).

  Thereafter, the currents of the switches 23 and 24 are acquired (step S314). Then, the control unit 51 determines whether or not the current flowing through the switch 23 is larger than the current flowing through the switch 24 (step S315).

  When the current flowing through the switch 23 is larger (step S315: YES), the control unit 51 closes the switch unit Sb3 (step S316). Then, the control unit 51 opens the switch unit Sb4 of the switch 24 that is requested (determined) to be opened (step S317), and ends the switching process.

  When the current flowing through the switch 24 is larger (step S315: No), the control unit 51 closes the switch unit Sa4 (step S318). Then, the control unit 51 opens the switch units Sa4 and Sb4 of the switch 24 that is requested (determined) to be opened (step S319). Then, the control part 51 closes switch part Sb3 (step S320), and complete | finishes a switching process.

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

  When the switches 23 and 24 are switched, it is possible to restrict current from flowing from the connection point N4 to the storage batteries 11 and 12 while continuously supplying power from the storage batteries 11 and 12 to the electric load 15. In addition, when switching of the switches 23 and 24 is requested, the switch units Sb3 and Sa4 are both opened, and the other switch units Sa3 and Sb4 are closed. Judge whether it is high. For this reason, the time for determination can be ensured. Moreover, the storage battery 11 and 12 side with a high voltage value is determined based on the electric current of the switches 23 and 24, and the switch part by the side of the storage battery 11 and 12 with a high voltage value is closed among switch part Sa4 and Sb4. For this reason, it can suppress that a big electric current flows into the parasitic diodes Db3 and Da4 continuously.

(Other embodiments)
The present invention is not limited to the above embodiment, and may be implemented as follows, for example. In the following, parts that are the same or equivalent to each other in the respective embodiments are denoted by the same reference numerals, and the description of the same reference numerals is used.

  In the above embodiment, the lead storage battery 11 and the electrical load 13 are connected to the external terminal P0, the rotating electrical machine 14 is connected to the external terminal P1, and the electric load 15 is connected to the external terminal P2. However, it may be applied to other in-vehicle power supply systems. For example, the storage batteries 11 and 12 may be connected in parallel to the alternator 70 as a generator, and the storage batteries 11 and 12 may be connected in parallel to the electric load 15. .

  This in-vehicle power supply system will be described in detail. As shown in FIG. 9, a lead storage battery 11, an alternator 70 as a generator, an electrical load 13 and the like are connected to an external terminal P0 of the battery unit U, and an electrical load 15 and the like are connected to an external terminal P2. In the battery unit U, a switch 23 is provided in the electrical path L3 between the external terminals P0 and P2, and a switch 24 is provided in the electrical path L4 between the lithium ion storage battery 12 and the external terminal P2. Further, the battery unit U is provided with a bypass path B2 that bypasses the switch 23, and a bypass opening / closing circuit RE2 is provided in the bypass path B2.

  Even in such a power supply system, by performing the switching process, it is possible to restrict current from flowing from the electric load 15 side to any one of the storage batteries 11 and 12 while continuously supplying power to the electric load 15. Can do.

  In the above embodiment, the lead storage battery 11 is provided as the first storage battery and the lithium ion storage battery 12 is provided as the second storage battery, but this may be changed. As the second storage battery, a high-density storage battery other than the lithium ion storage battery 12, for example, a nickel-hydrogen battery may be used. In addition, as the first storage battery and the second storage battery, it is also possible to use the same storage battery (for example, a lead storage battery or a lithium ion storage battery).

  -In the said 2nd Embodiment, when the switch to open is a switch by the side of a storage battery with a high voltage value in a switching intermediate state, among the switch parts which the said switch has, from the connection point N4 side to the storage batteries 11 and 12 side The switch may be switched as it is without closing the switch connected in parallel to the parasitic diode that regulates the current. That is, when the switch to be opened is a switch on the storage battery side having a high voltage value in the switching intermediate state, the control unit 51 opens all the switch units of the switch while closing all the switch units of the switch to be closed. It may be.

  Specifically, when the determination result in step S306 of the switching process is positive (when the current flowing through the switch 23 is larger), the control unit 51 switches the switch 23 that is requested (determined) to be opened. The part Sa3 is opened, the switch part Sa4 is closed, and the switching process is terminated. In this way, it is possible to omit the opening / closing process of closing the switch portion Sb3 and then opening the switch portion Sb3, thereby shortening the time for switching the switch.

  Similarly, when the determination result of step S315 of the switching process is negative (when the current flowing through the switch 24 is larger), the control unit 51 switches the switch unit Sb4 of the switch 24 that is requested (determined) to be opened. Is opened, the switch Sb3 is closed, and the switching process is terminated. In this way, it is possible to omit the opening / closing process of closing the switch part Sa4 once and then opening it, thereby shortening the time for switching the switch.

  -The power supply system can be used for purposes other than vehicles.

  The control unit 51 opens both the switch units Sb3 and Sa4 connected in parallel with the parasitic diodes Db3 and Da4 that regulate the current from the electric load 15 side to the storage batteries 11 and 12, and then the switch 23, 24 may be switched. That is, at the time of the switching request of the switches 23 and 24, regardless of the voltage difference between the storage batteries 11 and 12, the switch parts Sb3 and Sa4 are both opened and the other switch parts Sa3 and Sb4 are closed. After that, the control unit 51 opens the switch units provided in the electrical paths L3 and L4 that are in a state where the energization is cut off. In that case, it is desirable to close the switch part provided in the electrical paths L3 and L4 to be energized among the switch parts Sb3 and Sa4. Hereinafter, the switching process will be described in detail with reference to FIG.

  The control unit 51 determines whether or not a switching request has occurred (step S201). When the switching request has not occurred (step S201: NO), the control unit 51 ends the switching process.

  When the switching request has occurred (step S201: YES), the control unit 51 determines whether or not it is a switching request for opening the closed switch 23 (step S202).

  When it is a switching request for opening the switch 23 (step S202: YES), the control unit 51 opens the switch unit Sb3 of the switch 23 (step S203).

  Moreover, the control part 51 closes switch part Sb4 of the switch 24 (step S204). That is, the control unit 51 closes the switch unit Sb4 in order to open the switch units Sb3 and Sa4 and to close the switch units Sa3 and Sb4 (in order to make the switch intermediate state).

  After a predetermined time has elapsed from step S204, the control unit 51 opens the switch unit Sa3 of the switch 23 requested to be opened (determined) (step S205). The control unit 51 closes the switch unit Sa4 (step S206) and ends the switching process.

  When it is not a switching request for opening the switch 23 (step S202: NO), the control unit 51 opens the switch unit Sa4 of the switch 24 (step S207). The control unit 51 closes the switch unit Sa3 of the switch 23 (step S208). In other words, the control unit 51 closes the switch unit Sa3 in order to open the switch units Sb3 and Sa4 and to close the switch units Sa3 and Sb4 (in order to set the switch units Sa3 and Sb4 to the switching intermediate state).

  After a predetermined time has elapsed from step S208, the control unit 51 opens the switch unit Sb4 of the switch 24 that is requested (determined) to be opened (step S209). Moreover, the control part 51 closes switch part Sa3 (step S210), and complete | finishes a switching process. Thereby, the voltage value on the lead storage battery 11 side may be compared with the voltage value on the lithium ion storage battery 12 side.

  DESCRIPTION OF SYMBOLS 11 ... Lead storage battery, 12 ... Lithium ion storage battery, 15 ... Electric load, 21-24 ... Switch, 21a-24a, 21b-24b ... Semiconductor switch, 51 ... Control part, Da1-Da4, Db1-Db4 ... Parasitic diode, Sa1 ~ Sa4, Sb1 ~ Sb4 ... switch part, U ... battery unit.

Claims (8)

In the power supply device (U) applied to the power supply system in which the first storage battery (11) and the second storage battery (12) are connected in parallel to the electrical load (15),
A first opening / closing part (21, 23) provided on the first storage battery side of the connection point (N1, N4) to the electrical load in an electrical path between the first storage battery and the second storage battery;
A second opening / closing portion (22, 24) provided closer to the second storage battery than the connection point in the electrical path;
A controller (51) for controlling the first opening / closing part and the second opening / closing part;
The first opening and closing part and the second opening and closing part are configured by connecting first switches (21a to 24a) and second switches (21b to 24b) in series,
Each of the first switch and the second switch includes a diode (Da1 to Da4, Db1 to Db4) and a switch unit (Sa1 to Sa4, Sb1 to Sb4) connected in parallel with the diode,
The diode of the first switch and the diode of the second switch are provided in opposite directions,
When the control unit switches the storage battery that supplies power to the electric load between the first storage battery and the second storage battery, the control unit includes the switch unit included in the first opening / closing unit and the second opening / closing unit. The switch unit connected to the diode that regulates the current from the connection point side to the storage battery side is opened, and the switch unit that is in the same opening / closing unit as the switch unit and connected in series to the switch unit A power supply apparatus that controls each of the open / close units to switch the storage battery during the switching intermediate state after the switching intermediate state is set to the closed state.   The switch unit that is in an open state in the switching intermediate state is the switch unit included in the opening / closing unit provided on the storage battery side having a low voltage value among the first storage battery and the second storage battery. The power supply described. A detection unit that detects a current flowing through the first opening and closing unit and a current flowing through the second opening and closing unit;
The control unit is in an open state of all the switch units connected to a diode that regulates a current from the connection point side to the storage battery side among the switch units included in the first open / close unit and the second open / close unit. And, in the switching intermediate state in which all the switch units other than the switch unit are in the closed state, more of the first open / close unit and the second open / close unit based on the current detected by the detection unit Identify the opening / closing part where the current of
3. The power supply device according to claim 1, wherein the storage battery is switched in a state where all of the switch units included in the specified opening / closing unit are in a closed state.   When the specified opening / closing part is an opening / closing part that is required to be opened in switching of the storage battery, the control unit does not close all the switch parts of the specified opening / closing part. The power supply device according to claim 3, wherein all of the switch parts included in the specified opening / closing part are opened, and the storage battery is switched. The electric load includes a constant voltage load that requires constant voltage power,
The electric load (13) which requests | requires electric power temporarily is connected to either of the said 1st storage battery and the said 2nd storage battery separately from the said constant voltage load. The power supply device described in 1.   The power supply device according to any one of claims 1 to 5, wherein a generator (14, 70) for supplying electric power is connected to either the first storage battery or the second storage battery.   The power supply device according to any one of claims 1 to 6, wherein the control unit switches the storage battery when it is determined that an abnormality has occurred in the power supply device. In a power supply system comprising an electrical load (15) and a first storage battery (11) and a second storage battery (12) connected in parallel to the electrical load,
A first opening / closing part (21, 23) provided on the first storage battery side of the connection point (N1, N4) to the electrical load in an electrical path between the first storage battery and the second storage battery;
A second opening / closing portion (22, 24) provided closer to the second storage battery than the connection point in the electrical path;
A controller (51) for controlling the first opening / closing part and the second opening / closing part;
The first opening and closing part and the second opening and closing part are configured by connecting first switches (21a to 24a) and second switches (21b to 24b) in series,
Each of the first switch and the second switch includes a diode (Da1 to Da4, Db1 to Db4) and a switch unit (Sa1 to Sa4, Sb1 to Sb4) connected in parallel with the diode,
The diode of the first switch and the diode of the second switch are provided in opposite directions,
When the control unit switches the storage battery that supplies power to the electric load between the first storage battery and the second storage battery, the control unit includes the switch unit included in the first opening / closing unit and the second opening / closing unit. The switch unit connected to the diode that regulates the current from the connection point side to the storage battery side is opened, and the switch unit that is in the same opening / closing unit as the switch unit and connected in series to the switch unit A power supply system that controls each of the opening and closing units so as to switch the storage battery during the switching intermediate state after the switching intermediate state to be closed.

Images