JP6260422B2 - Battery unit - Google Patents

Description

  The present invention relates to a technique in which an external storage battery and a rotating machine having a power generation function can be connected to a battery unit having an internal storage battery.

  For example, a configuration in which a plurality of storage batteries (for example, a lead storage battery and a lithium ion storage battery) are used as an in-vehicle power supply system mounted on a vehicle and power is supplied to various in-vehicle electric loads while using each of these storage batteries properly is known. (For example, refer to Patent Document 1). Specifically, a semiconductor switch is provided in a connection path connecting a rotating machine and a lithium ion storage battery and a lead storage battery having a power generation function, and the rotation machine, the lithium ion storage battery, and the lead storage battery are electrically connected by opening and closing the semiconductor switch. It is set as the structure which conducts.

JP 2012-80706 A

  As a power supply system using the above two storage batteries, one storage battery (internal storage battery) and a semiconductor switch are built in the unit, and the other storage battery (external storage battery) is connected to two terminals of the unit (battery unit) having the internal storage battery. ) And a rotating machine can be connected to each other. Here, the terminal (first terminal) of the battery unit to which the external storage battery is connected and the terminal (second terminal) of the battery unit to which the rotating machine is connected are both power input / output terminals and have similar shapes. May have. In such a case, there is a concern that a reverse connection that connects the rotating machine to the first terminal and the external storage battery to the second terminal may occur during the assembly to the vehicle.

  Moreover, the connection between the first terminal and the external storage battery is cut off when the harness connecting the first terminal and the external storage battery is disconnected or the physical connection between the first terminal and the harness is released. There is a concern that connection interruption will occur.

  Here, under the situation where power generation is not performed in the rotating machine, the voltage is not applied to the first terminal from the outside of the battery unit in both reverse connection and connection disconnection. That is, under the situation where power generation is not performed in the rotating machine, it is not possible to distinguish between reverse connection and connection interruption, and there is a concern that fail-safe processing cannot be appropriately performed according to each abnormality.

  The present invention has been made to solve the above-described problems, and provides a means for appropriately performing fail-safe processing when a connection failure between a battery unit and an external storage battery occurs in a battery unit having an internal storage battery. The main purpose is to do.

  The present invention includes an internal storage battery (30), an external storage battery (20) is connected to the first terminal (P1), and a rotating machine (10) having a power generation function is connected to the second terminal (P2). A battery unit (U) that connects the first terminal and the second terminal and connects the internal storage battery to a battery connection point (N1) between the two terminals (N1). L1, L2), a first switch (51) provided between the first terminal and the battery connection point in the main connection path, an auxiliary terminal to which the external storage battery is connected, and the battery connection point A first bypass path (B1) connected to bypass the first switch, and a first bypass path (B1) that is provided on the first bypass path and is closed when the first switch is opened. , Bypassing the first switch The first bypass switch (55) for bringing the partial storage battery and the battery connection point into a conductive state, the voltage detection means (60) for detecting the voltage at the first terminal, and the first switch being opened. A connection failure determination means (60) for determining that a connection failure has occurred in which the external storage battery is not connected to the first terminal when the detected value of the voltage of the first terminal is lower than a predetermined value under the circumstances; And fail-safe means (60) for controlling both the first switch and the first bypass switch to a closed state when it is determined that the connection failure has occurred.

  Under the condition that the first switch is open, the detected value of the voltage at the first terminal should be equal to the output voltage of the external storage battery. In other words, when the detected value of the voltage at the first terminal is lower than the predetermined value under the condition where the first switch is in the open state, a connection failure occurs in which an external storage battery is not connected to the first terminal. Can be determined. This connection failure is caused by either the reverse connection in which the rotating machine is connected to the first terminal and the external storage battery is connected to the second terminal, or the connection interruption in which the connection between the first terminal and the external storage battery is cut off. It is believed that there is.

  A first bypass path is provided so as to bypass the first switch, and a first bypass switch is provided on the first bypass path. The first bypass switch is closed when the first switch is opened, thereby bypassing the first switch and bringing the external storage battery and the battery connection point (second terminal) into a conductive state. In a normal time when no connection failure has occurred, either one of the first switch and the first bypass switch is opened, and the other is closed.

  Since the auxiliary terminal is provided separately from the first terminal, it is considered that the auxiliary terminal and the external storage battery are normally connected even when a connection failure occurs in the first terminal. In the case of disconnection, the rotating machine and the external storage battery are connected via the auxiliary terminal and the first bypass switch. In the case of reverse connection, the rotating machine and the external storage battery are connected via the first switch. Therefore, when it is determined that a connection failure has occurred, both the first switch and the first bypass switch, which are normally opened and closed exclusively, are controlled to be closed. Thereby, even if any of reverse connection and connection interruption | blocking has arisen, it becomes possible to make a rotary machine and an external storage battery into a conduction | electrical_connection state. That is, even in a state where connection failure occurs at the first terminal, a state in which the rotating machine and the external storage battery are electrically connected can be maintained, and fail-safe processing can be suitably performed.

The electric circuit diagram which shows the power supply system of this embodiment. The figure which shows the state of each switch in a 1st state. The figure which shows the state of each switch in a 2nd state. The figure which shows the state of each switch in a 3rd state. The figure which shows the state of each switch in a 4th state. The figure which shows the state of each switch in a 5th state. The electric circuit diagram which shows the power supply system at the time of reverse connection. The electric circuit diagram which shows the power supply system at the time of a connection interruption | blocking. The flowchart showing a fail safe process. The flowchart showing an abnormality classification determination process.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Embodiments of the invention will be described below with reference to the drawings. The battery unit of this embodiment is applied to an in-vehicle power supply system mounted on a vehicle, and the vehicle travels using an engine (internal combustion engine) as a drive source. The vehicle has a so-called idling stop function.

  As shown in FIG. 1, the power supply system includes a rotating machine 10, a lead storage battery 20, a lithium ion storage battery 30, a starter 41, various electric loads 42 and 43, a P-MOS switch 51, a P-SMR switch 52, and an S- A MOS switch 53 and an S-SMR switch 54 are provided.

  Among these, the lithium ion storage battery 30 and each of the switches 51 to 54 are integrated by being accommodated in a casing (accommodating case) and configured as a battery unit U. Moreover, the battery unit U has the control part 60 which comprises a battery control means, and each switch 51-54 and the control part 60 are accommodated in the housing | casing in the state mounted in the same board | substrate.

  The battery unit U is provided with a first terminal P1, a second terminal P2, and a third terminal P3 as external terminals. The lead storage battery 20, the starter 41, and the electric load 42 are connected to the first terminal P1, The rotating machine 10 is connected to the two terminals P2, and the electric load 43 is connected to the third terminal P3. In this case, the lead storage battery 20 or the like is connected to the first terminal P1 via the harness H1, the rotating machine 10 is connected to the second terminal P2 via the harness H2, and the third terminal P3 via the harness H3. The electric load 43 is connected. Both the first terminal P1 and the second terminal P2 are large-current input / output terminals through which input / output currents of the rotating machine 10 flow.

  The rotating shaft of the rotating machine 10 is connected to a crankshaft of an engine (not shown) by a belt or the like, and the rotating shaft of the rotating machine 10 is rotated by the rotation of the crankshaft, and the rotating shaft of the rotating machine 10 is rotated Causes the crankshaft to rotate. In this case, the rotating machine 10 includes an electric power generation function for generating electric power (regenerative electric power generation) by rotating the crankshaft and a power output function for applying a rotational force to the crankshaft, and constitutes an ISG (Integrated Starter Generator). It has become.

  The lead storage battery 20 and the lithium ion storage battery 30 are electrically connected in parallel to the rotating machine 10, and the storage batteries 20, 30 can be charged by the generated power of the rotating machine 10. The rotating machine 10 is driven by power feeding from the storage batteries 20 and 30.

  The lead storage battery 20 is a well-known general-purpose storage battery. On the other hand, the lithium ion storage battery 30 is a high-density storage battery with less power loss during charging / discharging and higher output density and energy density than the lead storage battery 20. The lithium ion storage battery 30 is composed of an assembled battery formed by connecting a plurality of battery cells in series.

In the battery unit U, a plurality of connection paths L <b> 1 to L <b> 4 for connecting the terminals P <b> 1 to P <b> 3 and the lithium ion storage battery 30 to each other are provided as in-unit electrical paths. this house,
The first connection path L1 is an electrical path that connects the first terminal P1 and the second terminal P2,
The second connection path L2 is an electrical path that connects the connection point N1 (battery connection point) on the first connection path L1 and the lithium ion storage battery 30;
The third connection path L3 is an electrical path that connects the connection point N2 on the first connection path L1 and the third terminal P3,
The fourth connection path L4 is an electrical path that connects the connection point N3 of the second connection path L2 and the connection point N4 (load connection point) of the third connection path L3.
Among these, the first connection path L1 and the second connection path L2 correspond to “main connection paths”, and the third connection path L3 and the fourth connection path L4 correspond to “sub connection paths”.

And
A P-MOS switch 51 is provided in the first connection path L1 (specifically, between N1 and N2),
A P-SMR switch 52 is provided in the second connection path L2 (specifically, between N1 and N3),
An S-MOS switch 53 is provided in the third connection path L3 (specifically, between N2 and N4),
An S-SMR switch 54 is provided in the fourth connection path L4 (specifically, between N3 and N4).
Each of these switches 51 to 54 includes 2 × n MOSFETs (semiconductor switches) and is connected in series so that the parasitic diodes of the pair of MOSFETs are opposite to each other. By this parasitic diode, when each switch 51 to 54 is turned off, the current flowing through the path in which the switch is provided is completely cut off. In addition, the 1st connection path | route L1 and the 2nd connection path | route L2 are large current paths with which it is assumed that a comparatively big electric current flows between the rotary machine 10 and each storage battery 20,30. Further, the third connection path L3 and the fourth connection path L4 are small current paths that are assumed to flow a smaller current than the connection paths L1 and L2. Therefore, the switches 51 and 52 provided in the connection paths L1 and L2 have a larger allowable current amount than the switches 53 and 54 provided in the connection paths L3 and L4. Specifically, as the switches 51 and 52, more MOSFETs are connected in parallel than the switches 53 and 54, thereby increasing the allowable current amount.

  Further, the battery unit U is provided with bypass paths B1 and B2 that allow the lead storage battery 20 to be connected to the rotating machine 10 and the electric load 43 without using the switches 51 and 53 in the unit. Specifically, the battery unit U of the present embodiment is provided with a fourth terminal P4, and the lead storage battery 20, the starter 41, and the electric load 42 are connected to the fourth terminal P4 via a fuse 44. ing. The fourth terminal P4 is connected to the connection point N1 on the first connection path L1 by the first bypass path B1 inside the battery unit U. A first bypass switch 55 is provided on the first bypass path B1 to turn off the connection between the fourth terminal P4 and the connection point N1.

  Further, in the battery unit U, a second bypass path B2 is provided so as to connect the connection point N1 on the first connection path L1 and the third terminal P3. A second bypass switch 56 is provided on the second bypass path B2 to turn off the connection between the connection point N1 and the third terminal P3.

  The first bypass switch 55 and the second bypass switch 56 are normally closed relay switches. The lead storage battery 20 and the rotating machine 10 are connected by bypassing the P-MOS switch 51 by the first bypass path B1. Further, the first bypass path B1 and the second bypass path B2 are connected in series, thereby bypassing the S-MOS switch 53 and connecting the lead storage battery 20 and the electric load 43 to each other.

  The controller 60 switches the switches 51 to 54 between on (closed) and off (open). For example, at the time of discharge of each storage battery 20, 30, the switches 51 to 54 are basically controlled to cut off the mutual connection between the lead storage battery 20 and the lithium ion storage battery 30, and the lead storage battery 20 changes to the lithium ion storage battery 30. The flow of current and the flow of current from the lithium ion storage battery 30 to the lead storage battery 20 are suppressed. Thereby, the power loss accompanying a current flowing between both storage batteries can be suppressed.

  The control unit 60 is connected to an ECU 100 (electronic control device) outside the battery unit. That is, the control unit 60 and the ECU 100 are connected by a communication network such as CAN and can communicate with each other, and various data stored in the control unit 60 and the ECU 100 can be shared with each other. The ECU 100 performs idling stop control. As is well known, the idling stop control is to automatically stop the engine when a predetermined automatic stop condition is satisfied, and to restart the engine when the predetermined restart condition is satisfied under the automatic stop state.

  The electric load 43 is a constant voltage required electric load in which the voltage of the supplied power is substantially constant or the voltage fluctuation is required to be stable within a predetermined range. The lead load battery 20 is connected to the electrical load 43 via the S-MOS switch 53, and the lithium ion storage battery 30 is connected via the S-SMR switch 54. The lead storage battery 20 and the lithium ion storage battery 30 Power is supplied from either one.

  Specific examples of the electric load 43 include an in-vehicle navigation device and an in-vehicle audio device. For example, when the voltage of the supplied power is not constant and fluctuates greatly, or when it fluctuates greatly beyond the predetermined range, the voltage instantaneously drops below the minimum operating voltage, and the in-vehicle navigation There arises a problem that the operation of the device is reset. Therefore, the electric power supplied to the electric load 43 is required to be stable at a constant value where the voltage does not drop below the minimum operating voltage.

  The electric load 42 is a general electric load other than the electric load 43 (constant voltage required electric load) and the starter 41. Specific examples of the electric load 42 include wipers such as a headlight and a front windshield, a blower fan for an air conditioner, and a defroster heater for a rear windshield. The electric load 42 includes a driving load that shifts from a stopped state to a driven state when a predetermined driving condition is satisfied, and returns to the stopped state when the condition is not satisfied. The driving load is, for example, power steering or a power window.

  The rotating machine 10 generates power using the rotational energy of the crankshaft of the engine. The electric power generated by the rotating machine 10 is supplied to the electric loads 42 and 43 and also supplied to the lead storage battery 20 and the lithium ion storage battery 30. When the driving of the engine is stopped and power generation is not performed by the rotating machine 10, electric power is supplied from the lead storage battery 20 and the lithium ion storage battery 30 to the rotating machine 10, the starter 41, and the electric loads 42 and 43. The amount of discharge from each storage battery 20, 30 to the rotating machine 10, the starter 41 and the electric loads 42 to 43 and the amount of charge from the rotating machine 10 to each storage battery 20, 30 are determined by the SOC (State of of each storage battery 20, 30). charge: Control is performed so that the state of charge, that is, the ratio of the actual charge amount to the charge amount at the time of full charge, is in a range (appropriate range) in which overcharge / discharge does not occur.

  Control unit 60 detects the temperature, output voltage, and charge / discharge current of lithium ion storage battery 30, and calculates the SOC of lithium ion storage battery 30 based on the detected values. Further, the control unit 60 detects the temperature, output voltage, and charge / discharge current of the lead storage battery 20, and calculates the SOC of the lead storage battery 20 based on the detected values. The control unit 60 turns off the switches 51 to 54 based on the SOC of each storage battery, and performs control so that the SOC falls within an appropriate range. In addition, each of the switches 51 to 54 is provided with a current sensor, and the control unit 60 acquires a detected value of the current flowing through each of the switches 51 to 54. Moreover, the voltage sensor is provided in the terminals P1-P3 of the battery unit U, and the control part 60 acquires the detected value of the voltage of the terminals P1-P3, respectively.

  In the present embodiment, the decelerating regeneration is performed in which the rotating machine 10 is generated by the regenerative energy of the vehicle and charged to both the storage batteries 20 and 30 (mainly the lithium ion storage battery 30). This deceleration regeneration is performed under the control of the ECU 100 when conditions such as that the vehicle is decelerating and that fuel injection to the engine is cut off are satisfied.

  Here, both the storage batteries 20 and 30 are connected in parallel to the rotating machine 10. For this reason, when the electric power generated by the rotating machine 10 is charged, the storage battery having the lower terminal voltage is preferentially charged. At the time of regenerative power generation, the lithium ion storage battery 30 is charged with priority over the lead storage battery 20 so that the terminal voltage of the lithium ion storage battery 30 is lower than the terminal voltage of the lead storage battery 20. ing. Such a setting can be realized by setting the open end voltage and the internal resistance value of both the storage batteries 20 and 30. The open end voltage can be set using the positive electrode active material, the negative electrode active material and the electrolyte of the lithium ion storage battery 30. It can be realized by selecting.

  In the present embodiment, the engine is automatically stopped by idling stop control, and then the engine is automatically restarted by driving the rotating machine 10. Further, after the restart, output assist (start assist) for applying torque to the crankshaft is performed by the rotating machine 10 until the speed of the vehicle reaches a predetermined speed. Further, when the vehicle is running and the accelerator pedal is depressed by the driver to accelerate the vehicle, the rotating machine 10 performs output assistance (intermediate assist) that applies torque to the crankshaft. The intermediate assist is performed even in a situation where a high output is required for the crankshaft, such as when traveling on a steep slope. Both the start assist and the intermediate assist are performed under the control of the ECU 100. By performing the start assist and the intermediate assist, the fuel efficiency of the vehicle can be improved.

  A current corresponding to the amount of torque that the rotating machine 10 applies to the crankshaft supplies electric power to the rotating machine 10 as the rotating machine 10 is driven at the time of starting, starting assist, and intermediate assist. Flows into the storage battery. The output voltage of the storage battery is lowered by this current and the internal resistance of the storage battery. Due to the decrease in the output voltage of the storage battery according to the torque applied by the rotating machine 10, the voltage of the electric power supplied to the constant voltage requesting electric load 43 may also temporarily decrease, and an unexpected operation reset may occur. is there.

  Therefore, in the present embodiment, the control unit 60 appropriately controls the state of each of the switches 51 to 54 according to the traveling state of the vehicle, so that the operation of the constant voltage requesting electric load 43 is reset while the vehicle is traveling. Suppress defects. Specifically, the switches 51 to 54 are in the following first state to fifth state.

  In the first state shown in FIG. 2, the switches 51, 52, and 54 are turned on, and only the S-MOS switch 53 is turned off. In this first state, the lead storage battery 20 and the lithium ion storage battery 30 are in a conductive state, and both the storage batteries 20, 30 and the rotating machine 10 and the electrical load 43 are in a conductive state. At the time of regenerative power generation, the switch state is set to the first state in order to charge both storage batteries 20 and 30. In addition, the switch state is set to the first state also at the start assist after the idling stop restart.

  In the second state shown in FIG. 3, the switches 51 and 54 are turned on, and the switches 52 and 53 are turned off. In this second state, the lead storage battery 20 and the rotating machine 10 are in a conductive state, and the electrical load 43 and the lithium ion storage battery 30 are in a conductive state. Moreover, the lead storage battery 20 and the lithium ion storage battery 30 are cut off. A switch for the purpose of stabilizing the voltage of the electric power supplied to the electric load 43 at the time of running without assistance by the rotating machine 10 (during normal running), when the engine is stopped at idling stop, and when the engine is restarted at idling stop. Let the state be the second state.

  In the third state shown in FIG. 4, the switches 52 and 54 are turned on and the switches 51 and 53 are turned off. In the third state, the rotating machine 10 and the electric load 43 and the lithium ion storage battery 30 are in a conductive state. Moreover, the lead storage battery 20 and the lithium ion storage battery 30 are cut off. The purpose is to supply electric power from the lithium ion storage battery 30 to the rotating machine 10 to reduce the remaining capacity (charge rate) of the lithium ion storage battery 30 and to charge the lithium ion storage battery 30 with more power generated during regenerative power generation. As a result, at the time of intermediate assist, the switch state is basically set to the third state.

  In the fourth state shown in FIG. 5, the switches 51 and 53 are turned on, and the switches 52 and 54 are turned off. In the fourth state, the rotating machine 10, the electrical load 43, and the lead storage battery 20 are in a conductive state. Moreover, the lead storage battery 20 and the lithium ion storage battery 30 are cut off. In order to prevent overdischarge of the lithium ion storage battery 30, the switch state is set to the fourth state immediately after the IG is turned on and during cold start and when the remaining capacity of the lithium ion storage battery 30 is reduced.

  In the fifth state shown in FIG. 6, the switches 52 and 53 are turned on, and the switches 51 and 54 are turned off. In the fifth state, the rotating machine 10 and the lithium ion storage battery 30 are in a conductive state, and the electrical load 43 and the lead storage battery 20 are in a conductive state. Moreover, the lead storage battery 20 and the lithium ion storage battery 30 are cut off. At the time of the intermediate assist, when the current flowing through the rotating machine 10 is a predetermined amount or more and the output voltage of the lithium ion storage battery 30 is greatly reduced, the switch state is set to the fifth state.

  As described above, in the first state, the lead storage battery 20 and the lithium ion storage battery 30 are in a conducting state, and the lead storage battery 20, the lithium ion storage battery 30, the rotating machine 10, and the electric load 43 are in a conducting state. Moreover, in the 2nd-5th state, the lead storage battery 20 and the lithium ion storage battery 30 are made into the interruption | blocking state, and each of the rotary machine 10 and the electrical load 43 is electrically connected with either one of the lead storage battery 20 and the lithium ion storage battery 30. State.

  Here, if an open abnormality (always off abnormality) occurs in the P-MOS switch 51 while the in-vehicle power supply system is in the IG on state, power is supplied from the rotating machine 10 to the lead storage battery 20. I can't. In this case, as a result of the continued supply of electric power from the lead storage battery 20 to the electric load 42, the charge rate of the lead storage battery 20 decreases, and the electric load 42 eventually becomes a power failure. Therefore, the lead storage battery 20 and the rotating machine 10 are connected via the first bypass path B1. Thereby, when an open abnormality occurs in the P-MOS switch 51, the first bypass switch 55 is turned on, so that power can be supplied from the rotating machine 10 to the lead storage battery 20.

  In addition, when the lead storage battery 20 and the electrical load 43 are connected via the first bypass path B1 and the second bypass path B2 shown in FIG. 1, an abnormality occurs in the S-MOS switch 53 or the S-SMR switch 54. The bypass switch 55 and 56 are both turned on (on operation). Thereby, it becomes possible to supply electric power from the lead storage battery 20 to the electric load 43 without using both the switches 53 and 54, and the power supply failure in the electric load 43 can be suppressed.

  In addition, power supply (so-called dark current supply) to the electric loads 42 and 43 when the in-vehicle power supply system is in the IG off state is performed from the lead storage battery 20 in order to suppress the lithium ion storage battery 30 from being overdischarged. Is desirable. This is because lithium ion storage batteries have a greater degree of deterioration due to overdischarge than lead storage batteries. In addition, in order to suppress power consumption required for driving the MOS-FET (for example, power consumption due to gate leakage current), it is desirable that the switches 51 to 54 are turned off during dark current supply.

  Therefore, when the IG is turned off, power is supplied from the lead storage battery 20 to the electric load 43 via the first bypass path B1 and the second bypass path B2. That is, the control unit 60 turns on the bypass switches 55 and 56 on condition that the IG is off. Since the first bypass switch 55 and the second bypass switch 56 provided on the first bypass path B1 and the second bypass path B2 are normally closed relay switches, a current for driving the relay switch is not supplied. When stopped, it is turned on. That is, it is possible to suppress power consumption associated with keeping the switch in a conductive state when supplying dark current.

  Thus, the first bypass switch 55 is turned on when the P-MOS switch 51 is turned off, and the second bypass switch 56 is turned off with the S-MOS switch 53 and the S-SMR switch 54 being turned off. When it is in a state, it is turned on. That is, in normal times, the P-MOS switch 51 and the first bypass switch 55 are not turned on at the same time, and the S-MOS switch 53 or the S-SMR switch 54 and the second bypass switch 56 are simultaneously turned on. It is never turned on.

  Further, the fourth terminal P4 of the battery unit U and the connection point N5 to which the first terminal P1 and the lead storage battery 20 are connected are connected by a harness H4. A fuse 44 is provided on the harness H4. If a ground fault occurs in the second terminal P2 or the harness H2 while the first bypass switch 55 is turned on, a large current flows from the lead storage battery 20 to the point where the ground fault occurs. In addition, if a ground fault occurs in the third terminal P3 or the harness H3 while the first bypass switch 55 and the second bypass switch 56 are in the on state, the ground fault from the lead storage battery 20 is large. Current flows. When such a large current flows, the fuse 44 is blown, so that it is possible to suppress a secondary failure associated with the continuous large current.

  Since the bypass paths B1 and B2 are connected in series, it is not necessary to provide the fuse 44 for each of the bypass paths B1 and B2, and the number of parts can be reduced. Since the fuse 44 is provided outside the battery unit U, the fuse 44 can be easily replaced when the fuse 44 is blown.

  In addition, a fuse 45 is provided between the lithium ion storage battery 30 of the battery unit U and the casing (GND) of the battery unit U. If a ground fault occurs in the second terminal P2 or the harness H2 while the P-SMR switch 52 is in the on state, a large current flows from the lithium ion storage battery 30 to the point where the ground fault occurs. When such a large current flows, the fuse 45 is blown, so that it is possible to suppress a secondary failure caused by a large current continuing to flow from the lithium ion storage battery 30.

  As described above, in the first terminal P1 and the second terminal P2 of the battery unit U, the lead storage battery 20, the starter 41, and the electric load 42 are connected to the first terminal P1, and the rotation is performed to the second terminal P2. Machine 10 is connected. Further, the first terminal P1 and the fourth terminal P4 of the battery unit U are provided as separate bodies, and the harness H1 is connected to the first terminal P1, and the harness H4 is connected to the fourth terminal P4.

  When assembling to the vehicle, it is conceivable that an error in assembling the harnesses H1 and H2 to the terminals P1 and P2 of the battery unit U occurs. Specifically, there is a possibility that a connection failure (reverse connection) is made such that the rotating machine 10 is connected to the first terminal P1 and the lead storage battery 20 is connected to the second terminal P2. An electric circuit diagram at the time of reverse connection is shown in FIG. Also at the time of reverse connection, the lead storage battery 20, the starter 41, the electric load 43, and the fourth terminal P4 are connected via the harness H4 as in the case of normal connection.

  Moreover, about the connection failure of the 1st terminal P1 and the lead storage battery 20, connection interruption | blocking with the 1st terminal P1 and the lead storage battery 20 can be considered besides said reverse connection. An electric circuit diagram at the time of disconnection is shown in FIG. At the time of disconnection, the connection between the first terminal P1 and the harness H1 is interrupted, but the fourth terminal P4 and the lead storage battery 20 are connected via the harness H4. The disconnection may occur not only when the battery unit U is assembled to the vehicle, but also due to disconnection caused by vibration during traveling of the vehicle. Moreover, it may occur when the harness H1 is cut for some reason.

  Here, when the reverse connection occurs and when the connection is interrupted and the current is not flowing through the rotating machine 10 and the switches 51 to 54 are turned off, A voltage is not applied to the first terminal P1. That is, when the vehicle is stopped, it cannot be determined whether connection interruption or reverse connection occurs. Note that, when the vehicle is stopped, the first bypass switch 55 and the second bypass switch 56 are both turned on, so that power can be supplied from the lead storage battery 20 to the electric load 43.

  Therefore, a failure that does not cause inconvenience such as power failure even if reverse connection or connection disconnection occurs when no voltage is applied to the first terminal P1 when the vehicle is stopped. Perform safe processing. Specifically, switch control is performed so that the P-MOS switch 51, the S-MOS switch 53, the first bypass switch 55, and the second bypass switch 56 are turned on.

  When reverse connection occurs, the lead storage battery 20 and the rotating machine 10 are connected via the P-MOS switch 51. Further, the lead storage battery 20 and the electric load 43 are connected via a P-MOS switch 51 and an S-MOS switch 53. That is, since the P-MOS switch 51 and the S-MOS switch 53 are turned on by the fail-safe process described above, the rotating machine 10, the lead storage battery 20, and the electric load 43 are brought into conduction. The power failure of the load 43 can be suppressed, and the lead storage battery 20 can be charged.

  When the connection between the first terminal P <b> 1 and the lead storage battery 20 is cut off, the lead storage battery 20 and the rotating machine 10 are connected via the first bypass switch 55. In addition, the lead storage battery 20 and the electric load 43 are connected via the first bypass switch 55 and the second bypass switch 56. That is, since the first bypass switch 55 and the second bypass switch 56 are turned on by the fail-safe process, the rotating machine 10, the lead storage battery 20, and the electric load 43 are brought into conduction. The power failure of the load 43 can be suppressed, and the lead storage battery 20 can be charged.

  Further, at the time of disconnection, the rotating machine 10 and the lead storage battery 20 are connected via the fuse 44. Therefore, as a fail-safe process, in addition to the above switch control, in order to prevent the fuse 44 from being blown, control is performed to suppress the generated current output from the rotating machine 10 to a predetermined value or less.

  FIG. 9 shows a flowchart representing the fail-safe process in the present embodiment. This fail-safe process is performed by the control unit 60 at predetermined intervals.

  In step S11, it is determined whether or not the in-vehicle power supply system is changed from the IG off state to the IG on state. When the in-vehicle power supply system is in the IG off state (S11: NO), in step S12, the switches 51 to 54 are turned off, the bypass switches 55 and 56 are turned on, and the process is terminated.

  When the in-vehicle power supply system is changed from the IG off state to the IG on state (S11: YES), in step S13, the detection value Vin of the voltage at the first terminal P1 is acquired. In step S14, it is determined whether or not the detected value Vin is greater than or equal to a predetermined threshold value Va. When the detected value Vin is equal to or greater than the predetermined threshold value Va (S14: YES), in step S15, it is determined that the lead storage battery 20 is normally connected to the first terminal P1, and normal processing is performed for the switch state and the processing is terminated. To do. For example, immediately after the IG is turned off to the IG on state, the switch state is changed to the fourth state shown in FIG. 5, and both the bypass switches 55 and 56 are turned off.

  Further, when the detected value Vin is smaller than the predetermined threshold value Va (S14: NO), in step S16, the lead storage battery 20 is not connected to the first terminal P1, and a connection failure (reverse connection or connection disconnection) occurs. And determines that the battery unit U is in a fail-safe state and ends the process. Here, the fail safe state means that the P-MOS switch 51, the S-MOS switch 53, the first bypass switch 55 and the second bypass switch 56 are turned on, and the generated power of the rotating machine 10 is a predetermined value. It means to suppress to the following.

  Further, after the P-MOS switch 51, the S-MOS switch 53, the first bypass switch 55, and the second bypass switch 56 are turned on as described above, based on the detected value of the current flowing through each switch. Thus, it can be determined whether reverse connection or connection disconnection occurs.

  At the time of reverse connection, a current flows from the rotating machine 10 connected to the first terminal P <b> 1 to the lead storage battery 20 through the P-MOS switch 51. Further, a current flows from the rotating machine 10 connected to the first terminal P <b> 1 to the electric load 43 through the S-MOS switch 53. That is, at the time of reverse connection, in the P-MOS switch 51, a current flows from the first terminal P1 toward the second terminal P2.

  At the time of disconnection, a current flows from the rotating machine 10 connected to the second terminal P <b> 2 to the lead storage battery 20 via the first bypass switch 55. In addition, a current flows from the rotating machine 10 connected to the second terminal P <b> 2 to the electric load 43 through the P-MOS switch 51, the S-MOS switch 53, and the second bypass switch 56. That is, at the time of disconnection, in the P-MOS switch 51, a current flows from the second terminal P2 toward the first terminal P1.

  Therefore, based on the direction of the current flowing through the P-MOS switch 51 when the rotating machine 10 generates power, it can be determined whether reverse connection or connection disconnection has occurred.

  A flowchart showing the abnormality type determination process in the present embodiment is shown in FIG. The abnormality type determination process is performed by the control unit 60 at predetermined intervals while the IG is on.

  In step S21, it is determined whether or not the switch state is a fail-safe state. When the switch state is not the fail safe state (S21: NO), the process is terminated. When the switch state is the fail-safe state (S21: YES), in step S22, the power generation information of the rotating machine 10 is acquired from the ECU 100, and it is determined whether the rotating machine 10 is in the power generation state based on the acquired information. To do. When the rotating machine 10 is not in the power generation state (S22: NO), the process is terminated. When the rotating machine 10 is in the power generation state (S22: YES), the detected value Ipm of the current flowing through the P-MOS switch 51 is acquired in step S23. In step S24, based on the detection value Ipm, it is determined whether reverse connection or connection disconnection has occurred, and the process ends. Specifically, it is determined that reverse connection has occurred when current flows from the first terminal P1 toward the second terminal P2, and it is determined that connection interruption has occurred in other cases.

  When reverse connection occurs, since the rotating machine 10 and the lead storage battery 20 are connected via the P-MOS switch 51, it is not necessary to limit the generated power output from the rotating machine 10. On the other hand, when the connection is cut off, the rotating machine 10 and the lead storage battery 20 are connected via the first bypass switch 55 and the fuse 44, so that the rotating machine 10 is prevented from fusing in the fuse 44. It is good to limit the generated power output from. That is, it is determined whether reverse connection or connection disconnection occurs, and based on the determination result, the restriction on the generated power of the rotating machine 10 is canceled at the time of reverse connection, and the generated power of the rotating machine 10 is disconnected at the time of connection disconnection. It is good to continue the restriction.

  Hereinafter, effects in the present embodiment will be described.

  A first bypass path B1 is provided so as to bypass the P-MOS switch 51, and a first bypass switch 55 is provided on the first bypass path B1. The first bypass switch 55 is turned on when the P-MOS switch 51 is turned off, thereby bypassing the P-MOS switch 51 and bringing the lead storage battery 20 and the second terminal P2 into conduction. To do. In a normal time when no connection failure occurs, one of the P-MOS switch 51 and the first bypass switch 55 is turned off and the other is turned on.

  Since the fourth terminal P4 is provided separately from the first terminal P1, the fourth terminal P4 and the lead storage battery 20 are normally connected even if a connection failure occurs in the first terminal P1. It is thought that there is. In the case of disconnection, the rotating machine 10 and the lead storage battery 20 are connected via the fourth terminal P4 and the first bypass switch 55. In the case of reverse connection, the rotating machine 10 and the lead storage battery 20 are connected via the P-MOS switch 51. That is, in the case of connection interruption, if the process which makes the 1st bypass switch 55 into an ON state is performed, the rotary machine 10 and the lead storage battery 20 can be made into a conduction state. Moreover, in the case of reverse connection, if the process which makes the P-MOS switch 51 into an ON state is performed, the rotary machine 10 and the lead acid battery 20 can be made into a conduction | electrical_connection state.

  Therefore, when it is determined that a connection failure has occurred, both the P-MOS switch 51 and the first bypass switch 55, which are normally turned on and off exclusively, are controlled to be in the on state. Thereby, it becomes possible to make the rotary machine 10 and the lead-acid battery 20 into a conductive state when any of reverse connection and connection interruption occurs. That is, even in a state where a connection failure occurs at the first terminal P1, the state in which the rotating machine 10 and the lead storage battery 20 are electrically connected can be maintained, and the fail-safe process can be suitably performed.

  When the IG is turned on, since the rotating machine 10 is not in the power generation state, no voltage is applied from the rotating machine 10 to the first terminal P1 during reverse connection. That is, it is possible to suppress erroneous determination that the lead storage battery 20 is connected to the first terminal P1 by applying a voltage from the rotating machine 10 to the first terminal P1 despite the reverse connection. be able to. In addition, when IG is turned on, it is possible to appropriately perform fail-safe processing after IG is turned on by determining a connection failure, and to suppress secondary damage caused by reverse connection and connection disconnection. it can.

  By performing the above abnormality type determination process, it becomes possible to determine which of the connection failures is reverse connection or connection disconnection, and take appropriate measures when each of the abnormalities of reverse connection and connection disconnection occurs. It becomes possible to do.

  As a fail-safe process, in addition to the P-MOS switch 51 and the first bypass switch 55, the S-MOS switch 53 and the second bypass switch 56 are turned on. Thereby, it can suppress that the electric load 43 becomes a power failure.

(Other embodiments)
The fail safe process may be performed while the P-MOS switch 51 is in the off state, or may be performed while the IG is off. Moreover, you may implement on condition that harness H1-H4 was each assembled | attached to terminal P1, P2, P3 of the battery unit U. FIG. With this configuration, it becomes possible to determine a connection failure earlier.

  The battery unit U may be configured such that switches other than the P-MOS switch 51 and the first bypass switch 55 are omitted. Also in this configuration, when both the P-MOS switch 51 and the first bypass switch 55 are turned on when reverse connection or connection disconnection occurs, fail-safe processing can be performed appropriately.

  -As a fail-safe state, instead of the configuration in which both the S-MOS switch 53 and the second bypass switch 56 are turned on, either the S-MOS switch 53 or the second bypass switch 56 is turned on and the other is turned off. It is good also as a structure made into a state. Even when such control is performed, power supply failure in the electric load 43 can be suppressed.

  -The 2nd bypass path should just connect lead acid battery 20 and the 3rd terminal P3, and supply electric power to electric load 43 from lead acid battery 20. For example, the second bypass path may be provided so as to connect the connection point N2 on the first connection path L1 and the third terminal P3. In this case, the second bypass switch brings the connection between the connection point N2 and the third terminal P3 into a cut-off state or a conductive state.

  -It is good also as a structure in which the rotary machine 10 has only a power generation function.

  Although the lead storage battery 20 is used as the first storage battery and the lithium ion storage battery 30 is used as the second storage battery, this may be changed. For example, a nickel hydride storage battery, a nickel cadmium storage battery, or the like may be used as the first storage battery and the second storage battery.

  DESCRIPTION OF SYMBOLS 10 ... Rotating machine, 20 ... Lead storage battery (external storage battery), 30 ... Lithium ion storage battery (internal storage battery), 43 ... Electrical load, 51 ... P-MOS switch (first switch), 55 ... First bypass switch, 60 ... Control unit, L1, L2 ... main connection path, B1 ... first bypass path, P1 ... first terminal, P2 ... second terminal, P4 ... auxiliary terminal, U ... battery unit.

Claims (4)

A battery having an internal storage battery (30), an external storage battery (20) connected to the first terminal (P1), and a rotating machine (10) having a power generation function connected to the second terminal (P2) A unit (U),
A main connection path (L1, L2) for connecting the first storage terminal and the second terminal, and connecting the internal storage battery to a battery connection point (N1) between the two terminals;
A first switch (51) provided between the first terminal and the battery connection point in the main connection path;
A first bypass path (B1) for connecting the auxiliary terminal (P4) to which the external storage battery is connected and the battery connection point so as to bypass the first switch;
Provided on the first bypass path and closed when the first switch is open, bypassing the first switch and conducting the external storage battery and the battery connection point A first bypass switch (55),
Voltage detection means (60) for detecting the voltage of the first terminal;
When the detected value of the voltage of the first terminal is lower than a predetermined value under the condition where the first switch is in an open state, a connection failure is caused in which the external storage battery is not connected to the first terminal. Connection failure determination means (60) for determining
Fail-safe means (60) for controlling both the first switch and the first bypass switch to a closed state when it is determined that the connection failure has occurred;
A battery unit comprising: The battery unit is an in-vehicle battery unit mounted on a vehicle,
The connection failure determination means determines that a connection failure in which the external storage battery is not connected to the first terminal has occurred when the power state of the vehicle is turned on. The battery unit according to 1. Current detection means (60) for detecting a current flowing through the first switch;
The detected value of the current flowing through the first switch when power is being generated by the rotating machine in a state where both the first switch and the first bypass switch are closed by the fail-safe means. Based on the reverse connection, the rotating machine is connected to the first terminal and the external storage battery is connected to the second terminal, and the first terminal and the external storage battery (20) An abnormality type determination means (60) for determining which of the connection interruptions that will cause the connection to be blocked;
The battery unit according to claim 1, further comprising: A third terminal (P3) to which the electrical load (43) is connected;
A second switch (53) provided in a sub-connection path (L3) connecting an intermediate point (N2) between the first terminal and the first switch and the third terminal; and the battery connection point and the Load opening and closing means (53, 56) constituted by at least one of the second bypass switch (56) provided in the second bypass path (B2) connecting the third terminal;
With
The fail-safe means closes the load opening / closing means in addition to the first switch and the first bypass switch when the connection failure determination means determines that the connection failure has occurred. The battery unit according to any one of claims 1 to 3.

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