JP2016203969A - Power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply unit that can appropriately perform discharging to an electric load.SOLUTION: A power supply system, which comprises a lead battery 11 and a lithium ion battery 12 that are connected in parallel to a rotary electric machine 10 with power generation function, comprises: in an electric path L1 between the lead battery 11 and the lithium ion battery 12, serially-connected bodies of a switch 21 and a switch 22 having respective diode components D1 and D2 connected to face each other in a forward direction; and a connection point P1 which is an intermediate point between the switch 21 and the switch 22 and is connected to a first electric load 14.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device mounted on a vehicle or the like.

  As a power supply device mounted on a vehicle or the like, a configuration is known in which a plurality of storage batteries (lead storage battery, lithium ion storage battery, etc.) are used, and power is supplied to various on-vehicle electric loads while using each of these storage batteries properly.

  For example, in patent document 1, the 1st electric load is connected to the rotary electric machine and lithium ion storage battery side which have an electric power generation function, and the 2nd electric load is connected to the lead storage battery side. Moreover, the semiconductor switch is provided in the connection path which connects a lithium ion storage battery and a lead storage battery. Then, by turning on the semiconductor switch, the first electric load and the second electric load can be discharged by the two power sources of the lithium ion storage battery side and the lead storage battery.

JP 2011-230618 A

  However, in the above configuration, when the semiconductor switch is turned off, there is a case where the discharge to each electric load cannot be continued. For example, if a ground fault occurs and the semiconductor switch is turned off, it becomes impossible to discharge the electric load on the ground fault generation path side.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a power supply device that can appropriately discharge electric loads.

  A first invention made to solve the above problems is a power system including a first storage battery (11) and a second storage battery (12) connected in parallel to a rotating electrical machine (10) having a power generation function. A first switch (21) and a second switch (22) connected in series to each other with the forward direction of the diode components facing each other in the electrical path (L1) between the first storage battery and the second storage battery. A connection body and a connection point (P1) that is an intermediate point between the first switch and the second switch and connects an electric load (14) are provided.

  According to the first invention, the first switch and the second switch are connected so that the forward directions of the diode components face each other, and the connection point for connecting the electrical load is provided at the intermediate point. In addition to the case where each switch is on, also when each switch is off, discharging to the electrical load is possible via the diode provided in each switch. Therefore, it is possible to ensure the redundancy of power supply by the two power sources for the electric load regardless of whether the first switch and the second switch are on or off.

  The second invention is characterized by comprising switch control means (40) for individually turning on and off the first switch and the second switch.

  According to the second invention, since the first switch and the second switch are individually turned on / off, the first switch in the on state is turned on by turning on one of the first switch and the second switch and turning off the other. It is possible to perform both energization through the second switch and energization through the diodes of the first and second switches in the off state.

  According to a third aspect of the present invention, the switch control means turns on a storage battery side switch that prioritizes discharge to the electric load among the storage batteries, and turns off a storage battery side switch that does not prioritize discharge to the electric load. Features.

  According to the third invention, in order to turn off the switch on the storage battery side that gives priority to the discharge to the electric load among the first storage battery and the second storage battery, and to turn off the switch on the storage battery side that does not give priority to the discharge to the electric load. In a switch on the storage battery side that has no priority, a voltage drop occurs due to energization via a diode. As a result, the relative voltage of the storage battery that prioritizes discharge is increased relative to the voltage of the storage battery that does not prioritize discharge, and power is preferentially supplied to the electrical load from the storage battery prioritizing discharge. Can enhance the effect.

  According to a fourth aspect of the present invention, the rotating electrical machine is capable of powering drive, and is connected between a series connection body of the first switch and the second switch and the second storage battery, and the switch control means The first switch is turned on and the second switch is turned off in a state where the rotating electrical machine is driven by powering.

  According to the fourth aspect of the invention, since the first switch is turned on and the second switch is turned off in a state where the rotating electrical machine is driven by power running (vehicle acceleration state and idling stop control restart state), the second switch The discharge from the storage battery to the electric load can be suppressed, and the discharge from the first storage battery to the electric load can be more actively performed.

  In a fifth aspect of the invention, the rotating electrical machine is connected between a series connection body of the first switch and the second switch and the second storage battery, and the switch control means is based on power generation of the rotating electrical machine. It is characterized in that both the first switch and the second switch are turned on during charging (for example, during charging in the deceleration regeneration state).

  According to the fifth invention, when charging is performed by power generation of the rotating electrical machine in a vehicle deceleration state or the like, both the first switch and the second switch are turned on, so that the first storage battery and the second storage battery are turned on. The regenerative power can be supplied to each of the electric loads.

  6th invention is equipped with the opening-and-closing means (60) provided in parallel with the said series connection body between the said 1st storage battery and the said 2nd storage battery, The said switch control means is the time of the charge by the electric power generation of the said rotary electric machine, At least one of the first switch and the second switch is turned on, and the opening / closing means is turned on.

  According to the sixth aspect of the present invention, when the rotating electrical machine is charged by power generation, the open / close means provided in parallel to the series connection body is turned on (closed), whereby the electric power generated by the rotating electrical machine is stored via the open / close means. A charging path for supplying to the battery can be formed. In this case, between the first storage battery and the second storage battery, a charging path to the storage battery and a power feeding path to the electric load are formed in parallel. As a result, the current load of each switch constituting the series connection body is sufficient to satisfy the required power of the electric load. That is, by forming the charging path to the storage battery and the power feeding path to the electric load, it is possible to realize an appropriate circuit configuration in consideration of the magnitude of the assumed power in each path.

  According to a seventh aspect of the present invention, the electrical path in which the series connection body is provided between the first storage battery and the second storage battery is a load power supply path for passing a current according to the required power of the electrical load, The parallel path (L11) provided with the switching means is a large current path that allows energization of a larger current than the load power supply path.

  According to the seventh aspect, between the first storage battery and the second storage battery, the load power supply path and the large current path that allows energization of a larger current than the load power supply path are provided in parallel. Therefore, among these paths, the load feeding path can reduce the number of switches constituting the series connection body, while the large current path can increase the number of switches.

  If a rotating electrical machine with a large rated output is used, the assumed maximum power in the large current path increases according to the rated output. In such a case, however, the number of switches constituting the series connection body It is not necessary to increase each of them, and it can be dealt with only by dealing with the switching means on the large current path side.

  According to an eighth aspect of the present invention, there is provided a failure determination means (40) for determining the presence or absence of a failure in either the first switch or the second switch, and a determination that any one of the first switch or the second switch has failed. And a fail-safe means (40) for turning on the one of the first switch and the second switch that is not in failure and turning on the opening / closing means.

  According to the eighth invention, when one of the first switch and the second switch fails, by turning on the switch that has not failed among the first switch and the second switch and turning on the opening and closing means, It is possible to continue power supply to the electric load while allowing the rotating battery to charge the storage battery. Thereby, an appropriate fail-safe treatment can be performed.

  A ninth invention includes a ground fault determination means (40) for determining the presence or absence of a ground fault in the electrical path that electrically connects the first storage battery and the second storage battery, and the switch control means includes the first control battery. When a ground fault occurs on the first storage battery side of the switch, the first switch is turned off. When a ground fault occurs on the second storage battery side of the second switch, the second switch is turned off. It is characterized by being turned off.

  According to the ninth invention, when a ground fault occurs on the first storage battery side, when the first switch is turned off, even if the discharge from the first storage battery side to the electric load is stopped, the second storage battery The discharge from the side to the electric load can be continued. Further, when the second switch is turned off when a ground fault occurs on the second storage battery side, even if the discharge from the second storage battery side to the electric load is stopped, the first storage battery side to the electric load is stopped. Discharge can be continued.

  In a tenth aspect of the invention, each of the first switch and the second switch is configured by a parallel connection body of a plurality of semiconductor switches, and the switch control means is configured to charge the first storage battery and the second storage battery. According to the priority, which one of the plurality of semiconductor switches is turned on in the first switch and the second switch is switched.

  According to the tenth invention, when each of the first switch and the second switch is constituted by a parallel connection body of a plurality of semiconductor switches, the semiconductor switch to be turned on among the semiconductor switches constituting the parallel connection body By switching, the path resistance in the first switch and the second switch can be changed. Using this, each storage battery can be charged according to the priority of charge by switching on and off the first switch and the second switch according to the priority of charge.

  According to an eleventh aspect of the invention, the first storage battery and the second storage battery have different upper limit voltages, and the switch control means sets the upper limit voltage when charging the first storage battery and the second storage battery. Until one of the storage batteries on the lower side reaches the upper limit voltage, both the first storage battery and the second storage battery are charged, and after the one storage battery reaches the upper limit voltage, the other on the higher side of the upper limit voltage The first switch and the second switch are controlled to be turned on and off so as to preferentially charge the storage battery.

  According to the eleventh aspect, when the upper limit voltages of the first storage battery and the second storage battery are different, when charging each storage battery, the both storage batteries are charged until the storage battery having the lower upper limit voltage reaches the upper limit voltage. To do. And when the storage battery with the lower upper limit voltage reaches the upper limit voltage, the other storage battery with the higher upper limit voltage is preferentially charged. In this case, each storage battery can be charged closer to a fully charged state while avoiding an overvoltage state in which a voltage equal to or higher than the upper limit voltage is applied to each storage battery.

  According to a twelfth aspect of the present invention, the first storage battery and the second storage battery have different upper limit voltages, and the switch control means is configured such that the temperature of the storage battery on the lower side of the upper limit voltage is lower than a predetermined value. The switch of the storage battery having the lower upper limit voltage is turned off, and the switch of the storage battery having the higher upper limit voltage is turned on.

  According to the twelfth aspect, when the temperature on the side of the storage battery having the lower upper limit voltage is lower than a predetermined value, the voltage increase associated with charging in the storage battery is large and easily reaches the upper limit voltage. Therefore, by turning off the switch on the side of the storage battery with the lower upper limit voltage and turning on the switch on the side of the storage battery with the higher upper limit voltage, charging is performed via a diode on the side of the storage battery with the lower upper limit voltage turned off. As a result, an increase in charging voltage can be suppressed. And in the storage battery side by the side with a high upper limit voltage, it can charge more appropriately by suppressing the voltage rise of the storage battery by the side of the storage battery with a low upper limit voltage. Further, on the side of the storage battery having a lower upper limit voltage, the temperature increase caused by energization through the diodes promotes the temperature increase of the storage battery, and the voltage increase of the storage battery can be suppressed.

  In a thirteenth aspect of the present invention, when the voltage of the storage battery having a lower upper limit voltage among the first storage battery and the second storage battery reaches the upper limit voltage, the switch control means has a lower side of the upper limit voltage. The storage battery is switched off, and the switch on the storage battery side having the higher upper limit voltage is turned on.

  According to the thirteenth aspect, when the voltage on the storage battery side with the lower upper limit voltage reaches the upper limit voltage, the switch on the storage battery side with the lower upper limit voltage is turned off and the switch on the storage battery side with the higher upper limit voltage is turned on. Since it did in this way, the storage battery side with a high upper limit voltage can be charged in the state which stopped charge of the storage battery with a low upper limit voltage.

  14th invention is equipped with the 2nd opening-closing means (30) connected in series with respect to the said 2nd storage battery while being connected with respect to the serial connection body of the said 1st switch and the said 2nd switch, The said switch The control means turns on the second opening / closing means when permitting charging / discharging by the second storage battery, and turns off the second opening / closing means when prohibiting charging / discharging of the second storage battery. Features.

  According to the fourteenth aspect, regardless of the state of the first switch and the second switch, the charging / discharging permission / prohibition of the second storage battery can be switched by switching the open / close state of the second opening / closing means.

  In a fifteenth aspect of the invention, the second opening / closing means includes a series connection body of a third switch (31a) and a fourth switch (31b) in which the forward directions of the diode components are reversed.

  According to the fifteenth aspect, since the forward directions of the diode components of the third switch and the fourth switch are connected in opposite directions (because the anodes are connected), the second opening / closing means is turned off. In this case, it is possible to enhance the effect of interrupting the current flowing through the path provided with the second opening / closing means.

  In a sixteenth aspect of the invention, the switch control means turns on at least one of the first switch and the second switch, turns off the second opening / closing means, and prohibits the second opening / closing means when charging / discharging of the second storage battery is prohibited. The opening / closing means (60) provided in parallel with the series connection body between the first storage battery and the second storage battery is turned on.

  According to the sixteenth aspect, in a state where charging / discharging of the second storage battery is prohibited, at least one of the first switch and the second switch is on, the second opening / closing means is off, and the series connection body is provided in parallel. When the opening / closing means is turned on, the first storage battery can be charged by the rotating electrical machine, and the power supply to the electric load can be continuously performed.

  In a seventeenth aspect of the invention, the first storage battery is connected to a second electric load (13) having a larger required power than the electric load without going through a series connection body of the first switch and the second switch. It is characterized by being.

  According to the seventeenth aspect, by supplying power from the first storage battery to the second electric load without going through the series connection body of the first switch and the second switch, the second electric load having a large required power can be obtained. On the other hand, power can be supplied efficiently.

  In an eighteenth aspect of the invention, the second electrical load is a starter device that starts an engine, and the storage capacity of the first storage battery is larger than the storage capacity of the second storage battery.

  According to the eighteenth aspect, since the storage capacity of the first storage battery is larger than the storage capacity of the second storage battery, the startability of the starter device that starts the engine can be improved.

  The nineteenth invention is characterized in that the charge / discharge performance of the second storage battery is higher than the charge / discharge performance of the first storage battery.

  According to the nineteenth invention, the discharge from the second storage battery having high charge / discharge performance is more actively performed, so that the power of the first storage battery can be suppressed, and consequently the deterioration of the first storage battery can be suppressed. Can do.

  A twentieth aspect of the invention is a priority determination means (40) for determining the priority of charging the first storage battery and the second storage battery by comparing the state of charge of the first storage battery with the state of charge of the second storage battery. It is characterized by providing.

  According to the twentieth invention, both storage batteries can be charged in a well-balanced manner according to the state of charge of the first storage battery and the second storage battery.

The electric circuit diagram which shows the power supply system of this embodiment. The figure which shows SOC use range of a lead storage battery and a lithium ion storage battery. The flowchart of a ground fault determination process. The flowchart of a normal process. The electric circuit diagram which shows the power supply system of 2nd Embodiment. Explanatory drawing regarding the setting of the priority of charge of each storage battery. Explanatory drawing regarding the setting of the priority of charge of each storage battery. The flowchart of the charge control of 2nd Embodiment. The flowchart of the charge control of 2nd Embodiment. The electric circuit diagram which shows the power supply system of 3rd Embodiment. The flowchart of the charge control of 3rd Embodiment. The electric circuit diagram which shows the power supply system of 4th Embodiment. The circuit diagram which shows the electricity supply state at the time of deceleration regeneration. The circuit diagram which shows the electricity supply state at the time of the power running drive of a rotary electric machine. The circuit diagram which shows the electricity supply state at the time of the priority discharge of a lead storage battery. The circuit diagram which shows the electricity supply state at the time of the priority discharge of a lithium ion storage battery. The circuit diagram which shows the electricity supply state at the time of use stop of a lithium ion storage battery. The circuit diagram which shows the electricity supply state at the time of implementation of the fail safe 1. FIG. The circuit diagram which shows the electricity supply state at the time of implementation of the fail safe 2. FIG. The circuit diagram which shows the electricity supply state at the time of implementation of the fail safe 3. FIG.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. A vehicle on which the power supply system of this embodiment is mounted travels using an engine (internal combustion engine) as a drive source, and has a so-called idling stop function.

(First embodiment)
As shown in FIG. 1, the power supply system includes a rotating electrical machine 10, a lead storage battery 11, a lithium ion storage battery 12, a first electrical load 14, a second electrical load 13, a first switch unit 20, and a second switch unit 30. ing. Among these, the lithium ion storage battery 12, the 1st switch part 20, and the 2nd switch part 30 are integrated by being accommodated in the housing | casing (accommodating case) which is not shown in figure, and is comprised as the battery unit U.

  The battery unit U is provided with a first terminal T1, a second terminal T2, and a third terminal T3 as external terminals. The lead storage battery 11, the second electric load 13, and the first electric load 14 are connected to the first terminal T1, and the rotating electrical machine 10 is connected to the second terminal T2. A first electrical load 14 is connected to the third terminal T3. The terminals T1 and T2 are both large current input / output terminals through which input / output currents of the rotating electrical machine 10 flow.

  The rotating shaft of the rotating electrical machine 10 is drivingly connected to an engine output shaft (not shown) by a belt or the like, and the rotating shaft of the rotating electrical machine 10 is rotated by the rotation of the engine output shaft, while the rotating shaft of the rotating electrical machine 10 is rotated. As a result, the engine output shaft rotates. In this case, the rotating electrical machine 10 includes a power generation function that generates power (regenerative power generation) by rotating the engine output shaft and the axle, and a power output function (power running function) that applies rotational force to the engine output shaft. For example, an ISG (Integrated Starter Generator) is used for the rotating electrical machine 10.

  The lead storage battery 11 and the lithium ion storage battery 12 are electrically connected in parallel to the rotating electrical machine 10, and the storage batteries 11, 12 can be charged by the generated power of the rotating electrical machine 10. The rotating electrical machine 10 is driven by power feeding from the storage batteries 11 and 12.

  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. In this case, the lithium ion storage battery 12 corresponds to a second storage battery, which may be a storage battery having a higher output density or energy density than the lead storage battery 11.

  Specifically, the lead storage battery 11 has a positive electrode active material of lead dioxide (PbO2), a negative electrode active material of lead (Pb), and an electrolyte solution of sulfuric acid (H2SO4). And the some battery cell comprised from these electrodes is connected in series, and is comprised. In the present embodiment, the storage capacity of the lead storage battery 11 is set to be larger than the storage capacity of the lithium ion storage battery 12.

  On the other hand, an oxide containing lithium (lithium metal composite oxide) is used for the positive electrode active material of the lithium ion storage battery 12, and specific examples include LiCoO 2, LiMn 2 O 4, LiNiO 2, LiFePO 4, and the like. As the negative electrode active material of the lithium ion storage battery 12, carbon (C), graphite, lithium titanate (for example, LixTiO2), an alloy containing Si or Su, or the like is used. An organic electrolyte is used as the electrolyte of the lithium ion storage battery 12. And the some battery cell comprised from these electrodes is connected in series, and is comprised.

  In addition, the codes | symbols 11a and 12a in FIG. 1 represent the battery cell assembly of the lead storage battery 11 and the lithium ion storage battery 12, and the codes | symbols 11b and 12b represent the internal resistance of the lead storage battery 11 and the lithium ion storage battery 12. Moreover, in the following description, the open voltage V0 of the storage battery is a voltage generated by the battery cell assemblies 11a and 12a.

  The battery unit U is provided with a first connection path L1 and a second connection path L2 that connect the terminals T1 and T2 and the lithium ion storage battery 12 to each other as an in-unit electrical path. Of these, the first switch section 20 is provided in the first connection path L1 that connects the first terminal T1 and the second terminal T2, and the connection point N1 (battery connection point) and lithium ion on the first connection path L1. A second switch unit 30 is provided in the second connection path L <b> 2 that connects the storage battery 12. The second switch unit 30 corresponds to “second opening / closing means”.

  Each of the first switch unit 20 and the second switch unit 30 is configured as a series connection body of semiconductor switches. Each semiconductor switch includes a diode component connected in antiparallel. In this embodiment, an N-channel MOSFET is used as the semiconductor switch.

  Specifically, the first switch unit 20 is configured as a series connection body of two semiconductor switches (switches 21 and 22). The switches 21 and 22 are connected so that their drain terminals face each other. As a result, the cathode (forward direction) of the diode D1 on the switch 21 side and the cathode (forward direction) of the diode D2 on the switch 22 side face each other.

  The 2nd switch part 30 is provided with the switch 31 comprised as a serial connection body of two semiconductor switches (switch 31a, 31b). The switches 31a and 31b are connected so that their source terminals face each other. As a result, the anode of the diode D3 on the switch 31a side and the anode of the diode D4 on the switch 31b side face each other.

  In the first switch unit 20, a connection point P <b> 1 for connecting the first electrical load 14 is provided at a connection location between the drain terminals of the switches 21 and 22. The connection point P1 is connected to the third terminal T3 via the third connection path L3. When the first electrical load 14 is connected to the connection point P1, the diodes provided in the switches 21 and 22 are provided not only when the switches 21 and 22 are turned on but also when the switches 21 and 22 are turned off. Discharging to the first electric load 14 is possible via D1 and D2. In other words, regardless of whether the switches 21 and 22 are turned on or off, it is possible to supply power to the first electric load 14 from the two power sources.

  The first electric load 14 includes a constant voltage request load that is required to be stable so that the voltage of the supplied power is substantially constant or at least varies within a predetermined range, and a general load other than the constant voltage load. Yes.

  The first electric load 14 will be described in detail. The constant voltage request load includes a travel load related to vehicle travel and a load other than travel. Examples of the driving load include a brake device, an oil pump of an automatic transmission, a fuel pump, and an electric power steering. Examples of loads other than traveling include a navigation device, a display device that displays a meter, an audio device, and the like. The general load is a load that has a relatively wide voltage range that can be operated compared to the constant voltage required load, such as wipers such as headlights and front windshields, blower fans for air conditioners, heaters for defrosters for rear windshields, etc. Is mentioned. The second electric load 13 is a load that requires a large current to flow when the engine is started, and is, for example, a starter.

  The control unit 40 performs various processes in the power supply system. The control unit 40 is connected to an ECU 50 outside the battery unit. The control unit 40 and the ECU 50 are connected by a communication network such as CAN and can communicate with each other, and various data stored in the control unit 40 and the ECU 50 can be shared with each other. For example, the ECU 50 receives signals from various sensors that indicate the traveling state of the vehicle, such as an accelerator opening sensor and a brake sensor (not shown), and the detection signals of these various sensors are shared with the control unit 40.

  The ECU 50 is also an electronic control device having a function of performing idling stop control. As is well known, idling stop control automatically stops the engine when a predetermined automatic stop condition is satisfied, and restarts the engine when the predetermined restart condition is satisfied under the automatic stop condition. The engine is restarted by driving the rotating electrical machine 10.

  The rotating electrical machine 10 also serves as a generator that generates electric power using rotational energy of the engine output shaft. Specifically, when the rotor is rotated by the engine output shaft in the rotating electrical machine 10, an alternating current is induced in the stator coil in accordance with the exciting current flowing in the rotor coil, and is converted into a direct current by a rectifier (not shown). Then, the exciting current flowing through the rotor coil in the rotating electrical machine 10 is adjusted by the regulator, so that the voltage of the generated direct current is adjusted to a predetermined adjustment voltage Vreg (see FIG. 2).

  For example, when the vehicle performs steady running or is in an automatic stop state by idling stop control, power is not applied to the engine by driving the rotating electrical machine 10, and the vehicle is automatically stopped by acceleration state or idling stop control. At the time of restart from, power is applied to the engine by driving the rotating electrical machine 10.

  The electric power generated by the rotating electrical machine 10 is supplied to the first electric load 14 and to the lead storage battery 11 and the lithium ion storage battery 12. When the driving of the engine is stopped and no electric power is generated by the rotating electrical machine 10, electric power is supplied from the lead storage battery 11 and the lithium ion storage battery 12 to the first electric load 14. The amount of discharge from the lead storage battery 11 and the lithium ion storage battery 12 to the first electric load 14 and the amount of charge from the rotating electrical machine 10 are SOCs (State of charge: charge state, actual charge amount with respect to the charge amount at full charge). (Which is also a ratio) is appropriately adjusted so as to be in a range (SOC usage range) in which overcharge / discharge does not occur.

  Here, the setting of the SOC use range in each of the storage batteries 11 and 12 will be described in detail. FIG. 2 shows the correlation between the open circuit voltage (OCV) and the state of charge (SOC) of the lead storage battery 11 and the lithium ion storage battery 12. 2A shows the correlation between the open-circuit voltage of the lead storage battery 11 and the charged state, and FIG. 2B shows the correlation between the open-circuit voltage of the lithium ion storage battery 12 and the charged state. It is shown. FIG. 2B is also an enlarged view of an alternate long and short dash line portion (portion showing the SOC usage range W1 (Pb)) in FIG. 2A, and the lithium ion storage battery 12 shown on the horizontal axis of FIG. The SOC = 0% position corresponds to the SOCa value of the SOC usage range W1 (Pb). In both figures, it is assumed that the voltages Va and Vb have the same voltage value.

  The horizontal axis in FIG. 2A shows the SOC of the lead storage battery 11, and the solid line A1 in the figure is a voltage characteristic line showing the relationship between the SOC of the lead storage battery 11 and the open circuit voltage V0 (Pb). The open circuit voltage V0 (Pb) also increases in proportion to the increase in the amount of charge and the SOC. The horizontal axis in FIG. 2 (b) shows the SOC of the lithium ion storage battery 12, and the solid line A2 in the figure is a voltage characteristic line showing the relationship between the SOC of the lithium ion storage battery 12 and the open circuit voltage V0 (Li). As the amount of charge increases and the SOC increases, the open circuit voltage V0 (Li) also increases.

  In addition, when the storage batteries 11 and 12 are overcharged or overdischarged, there is a concern about early deterioration. Therefore, the charging / discharging amounts of the storage batteries 11 and 12 are regulated so that the SOC of each of the storage batteries 11 and 12 falls within a predetermined lower limit value and upper limit value range (SOC usage range) that does not cause overcharge / discharge. In FIG. 2A, the SOC usage range W1 of the lead storage battery 11 is shown, and in FIG. 2B, the SOC usage range W2 of the lithium ion storage battery 12 is shown.

  In this case, the control unit 40 limits the amount of charge to each of the storage batteries 11 and 12 in order to control the SOC of the lead storage battery 11 within the SOC use range W1 and the SOC of the lithium ion storage battery 12 within the SOC use range W2. Protection control is performed so as to protect the overcharge while limiting the discharge amount from the lead storage battery 11 and the lithium ion storage battery 12 as well as overcharge protection.

  Specifically, the control unit 40 constantly acquires the detected value of the terminal voltage or the open-circuit voltage V0 (Li) of the lead storage battery 11 and the lithium ion storage battery 12, and the lead storage battery 11 and the lithium ion detected by the current detection means (not shown). The current value flowing through the storage battery 12 is always acquired. For example, when the terminal voltage of each of the storage batteries 11 and 12 at the time of discharging is lower than the voltage (lower limit voltage) corresponding to the lower limit value of the SOC usage ranges W1 and W2, The overdischarge protection of the storage batteries 11 and 12 is intended. Moreover, the control part 40 implements overcharge protection (overvoltage protection) so that the terminal voltage of each storage battery 11 and 12 does not rise above the voltage (upper limit voltage) corresponding to the upper limit value of the SOC usage ranges W1 and W2. .

  Moreover, in this embodiment, the decelerating regeneration which performs the electric power generation of the rotary electric machine 10 with the regenerative energy of a vehicle and charges both the storage batteries 11 and 12 (mainly lithium ion storage battery 12) is performed. This deceleration regeneration is performed when conditions such as that the vehicle is decelerating and that fuel injection to the engine is cut are satisfied.

  Further, the control unit 40 controls switching of the first switch unit 20 between on (closed) and off (open). For example, the control unit 40 determines the presence / absence of a ground fault in the electrical path. If there is no ground fault, the controller 40 individually controls on / off of the switches 21 and 22 of the first switch unit 20 based on the driving state of the vehicle. To do. When there is a ground fault, on / off of each of the switches 21 and 22 of the first switch unit 20 is individually controlled according to the state of occurrence of the ground fault. In the present embodiment, after the IG switch is turned on, the second switch unit 30 is basically turned on.

  Specifically, in a normal state where no ground fault has occurred, in a state where no power is applied to the engine by driving the rotating electrical machine 10, such as when the driving state of the vehicle is a steady running state or when the idling stop control is automatically stopped. Then, the switch 21 is turned off, the switch 22 is turned on, and the lithium ion storage battery 12 is discharged preferentially to the first electrical load 14.

  On the other hand, in a state where power is applied to the engine by driving the rotating electrical machine 10, such as when the engine is restarted or during power assist (acceleration) by the rotating electrical machine 10, due to the influence of discharge from the lithium ion storage battery 12 to the rotating electrical machine 10. There is a risk of voltage fluctuations in the lithium ion storage battery 12. Under such circumstances, the switch 21 is turned on and the switch 22 is turned off to preferentially discharge the lead storage battery 11 to the first electric load 14 while suppressing the influence of voltage fluctuation.

  As described above, among the lead storage battery 11 and the lithium ion storage battery 12, the switch on the storage battery side that prioritizes discharge to the first electrical load 14 is turned on, and the switch on the storage battery side that does not prioritize discharge to the first electrical load 14 is turned off. In this case, the switch on the storage battery side that does not give priority to discharging is energized via a diode, resulting in a voltage drop. As a result, the relative voltage of the storage battery prioritizing discharge is increased relative to the voltage of the storage battery prioritizing discharge, and the discharge from the storage battery prioritizing discharge to the first electric load 14 can be more actively performed. it can.

  On the other hand, when a ground fault has occurred, on / off of the first switch unit 20 is controlled according to the state of occurrence of the ground fault. Specifically, when a ground fault occurs on the first terminal T1 side, that is, on the lead storage battery 11 side with respect to the switch 21, the switch 21 is turned off and the switch 22 is turned on. In this case, even if the discharge from the lead storage battery 11 to the first electric load 14 is stopped, the discharge from the lithium ion storage battery 12 to the first electric load 14 can be continued. Similarly, when a ground fault occurs on the second terminal T2 side, that is, on the lithium ion storage battery 12 side rather than the switch 22 side, the switch 21 is turned on and the switch 22 is turned off. In this case, even if the discharge from the lithium ion storage battery 12 to the electric load is stopped, the discharge from the lead storage battery 11 to the first electric load 14 can be continued.

  Here, the effect of the voltage drop of the diode will be described in more detail with reference to FIG. First, the open voltage V0 (Li) of the lithium ion storage battery 12 and the open voltage of the lead storage battery 11 are set in a specific region that is on the lower SOC side than the SOC use range W2 (Li) within the entire SOC range of the lithium ion storage battery 12. There is a point Vds1 that coincides with V0 (Pb), and in the SOC usage range W2 (Li), the entire range is “open voltage V0 (Pb) of open voltage V0 (Li)>”.

  In this case, in the region where “open voltage V0 (Li) <open voltage V0 (Pb)”, the lead-acid battery 11 is prioritized to discharge, and “open voltage V0 (Pb)> open voltage V0 (Pb)”. In such a region, the discharge of the lithium ion storage battery 12 is prioritized.

  In the present embodiment, the switches 21 and 22 of the first switch unit 20 are connected so that the cathodes of the diodes D1 and D2 face each other. Therefore, when one of the lead storage battery 11 side and the lithium ion storage battery 12 side is turned on and the other switch is turned off, the voltage drop due to the diode of the switch on the off side causes a point shown in FIG. It is possible to change Vds1 to either the side on which the SOC usage range W2 (Li) of the lithium ion storage battery 12 is expanded or the side on which it is reduced.

  Specifically, when the switch 21 is turned off and the switch 22 is turned on, the OCV of the lead storage battery 11 is substantially reduced in the SOC characteristics of the lithium ion storage battery 12 of FIG. 2B due to the voltage drop of the diode D1 of the switch 21. It can be in the state. In this case, when the point Vds1 shown in FIG. 2B is shifted to Vds2 on the low SOC side, the SOC usage range W2 (Li) is expanded to the low SOC side, and the discharge of the lithium ion storage battery 12 is performed. Can be performed more actively.

  When the switch 21 is turned on and the switch 22 is turned off, the OCV of the lithium ion storage battery 12 in the SOC characteristic of the lithium ion storage battery 12 of FIG. Can be lowered. In this case, when the point Vds1 shown in FIG. 2B is shifted to Vds3 on the high SOC side, the SOC usage range W2 (Li) is reduced to the high SOC side. In other words, the high SOC side of the SOC usage range W1 (Pb) of the lead storage battery 11 is expanded, and the lead storage battery 11 can be discharged more actively.

  Next, a processing procedure performed by the control unit 40 of this embodiment will be described with reference to the flowcharts of FIGS. The following processing is repeatedly performed by the control unit 40 at a predetermined cycle. 3 and 4, the control unit 40 basically maintains the second switch unit 30 in the on state, and switches the first switch unit 20 on and off.

  In FIG. 3, it is determined whether or not it is a normal state in which no ground fault has occurred (S11). This process is performed using a detection value of current detection means (not shown) that detects the discharge current of the lead storage battery 11 and the lithium ion storage battery 12, and is normal when the detection value of the current is less than a predetermined threshold value. When the detected current value is equal to or greater than a predetermined threshold value, the ground fault state is determined. When it determines with it being a normal state, on-off control of the switches 21 and 22 is controlled as a normal process according to the driving | running state of a vehicle (S12).

  Here, the normal process of S12 is demonstrated using FIG. First, it is determined whether or not the vehicle is in a steady running state (S21). Whether or not the vehicle is in a steady running state is determined based on detection signals from various sensors indicating the running state of the vehicle (not shown). The steady running state includes a state where the vehicle speed is substantially constant and the engine is idling.

  If it is determined in S21 that the vehicle is in the steady running state, the switch 21 is turned off and the switch 22 is turned on, giving priority to the discharge of the lithium ion storage battery 12 (S22). If it is determined in S21 that the vehicle is not in the steady running state, it is determined whether or not the vehicle is in a decelerating state (during regenerative charging) (S23). If it is determined in S23 that the vehicle is decelerating, both switches 21 and 22 are turned on (S24). In this case, the power generated by the power generation of the rotating electrical machine 10 is supplied to the storage batteries 11 and 12 and the first electric load 14.

  If it is determined in S23 that the vehicle is not in a deceleration state, it is determined whether or not the engine is in an automatic stop state by idling stop control (S25). This process makes a positive determination when the accelerator opening is zero and the vehicle speed is zero. When an affirmative determination is made in S25, the switch 21 is turned off, the switch 22 is turned on, and the lithium ion storage battery 12 is preferentially used to discharge the first electric load 14 (S26).

  If a negative determination is made in S25, it is determined whether the engine is restarted by the rotating electrical machine 10 or the power assist is performed by the rotating electrical machine 10 (ie, acceleration) (S27). When an affirmative determination is made in S27, the switch 21 is turned on, the switch 22 is turned off, and the discharge to the first electric load 14 is performed using the lead storage battery 11 preferentially (S28).

  On the other hand, if it is determined in S11 in FIG. 3 that a ground fault has occurred, it is determined whether or not the occurrence of the ground fault is on the first terminal T1 side (lead storage battery 11 side) (S13). This process makes an affirmative determination when the detected value of the current on the lead storage battery 11 side is equal to or greater than a predetermined determination value. If a ground fault occurs on the lead storage battery 11 side, the switch 21 is turned off and the switch 22 is turned on (S14). In this case, even if the discharge from the lead storage battery 11 is stopped, the discharge from the lithium ion storage battery 12 can be continued.

  When the ground fault is not on the first terminal T1 side, that is, on the second terminal T2 side (lithium ion storage battery 12 side), the switch 21 is turned on and the switch 22 is turned off (S15). In this case, even if the discharge from the lithium ion storage battery 12 is stopped, the discharge from the lead storage battery 11 can be continued.

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

  The switch 21 and the switch 22 are connected so that the forward directions of the diode components face each other, and a connection point P1 for connecting the first electric load 14 is provided at the intermediate point. In this case, in addition to the case where the switches 21 and 22 are turned on, the discharge to the first electric load 14 is caused via the diode component of the switches 21 and 22 when the switches 21 and 22 are turned off. It becomes possible. Therefore, it is possible to ensure redundancy of power supply by the two power sources to the first electric load 14 regardless of whether the switch 21 and the switch 22 are on or off.

  Since the switch 21 and the switch 22 are individually turned on and off, energization through the switches 21 and 22 in the on state and the diode D1 by turning on one of the switch 21 and the switch 22 and turning off the other. , D2 can be both energized.

  When the switch on the storage battery side that gives priority to the discharge to the first electric load 14 is turned on among the lead storage battery 11 and the lithium ion storage battery 12, the switch on the storage battery side that does not give priority to the discharge to the first electric load 14 is turned off. In a switch on the storage battery side that has no priority, a voltage drop occurs due to energization via a diode. Therefore, the relative voltage of the storage battery that gives priority to discharge is increased with respect to the voltage of the storage battery that gives priority to discharging, and the effect that priority is given to supplying power to the electric load from the storage battery giving priority to discharging. Can be increased.

  In a configuration in which the charge / discharge performance of the lithium ion storage battery 12 is higher than that of the lead storage battery 11 and the rotating electrical machine 10 is connected to the lithium ion storage battery 12 side, the rotating electrical machine 10 does not apply power to the engine (steady state of the vehicle In the driving state or the automatic stop state by idling stop control), the switch 21 is turned off and the switch 22 is turned on. Therefore, the discharge from the lead storage battery 11 to the first electric load 14 is suppressed, and the lithium ion storage battery 12 having a high charge / discharge performance is used. 1 The electric discharge to the electric load 14 can be more actively performed. In the state in which the rotating electrical machine 10 applies power to the engine (the vehicle acceleration state and the idling stop control restart state), the switch 21 is turned on and the switch 22 is turned off. The discharge to 14 can be suppressed, and the discharge from the lead storage battery 11 to the first electrical load 14 can be performed more actively.

  In the case of charging in which regenerative charging is performed in the deceleration state of the vehicle, both the switch 21 and the switch 22 are turned on to regenerate each of the lead storage battery 11, the lithium ion storage battery 12, and the first electric load 14. It can supply power for power generation.

  When the switch 21 is turned off when a ground fault occurs on the lead storage battery 11 side, even if the discharge from the lead storage battery 11 side to the first electric load 14 is stopped, the first is started from the lithium ion storage battery 12 side. The discharge to the electric load 14 can be continued. Further, when a ground fault occurs on the lithium ion storage battery 12 side, when the switch 22 is turned off, even if the discharge from the lithium ion storage battery 12 side to the first electric load 14 is stopped, the lead storage battery 11 side The discharge to the first electric load 14 can be continued.

  You may change the said embodiment as follows, for example. In addition, in the following description, the same figure number is attached | subjected about the same structure as the above-mentioned structure, and detailed description is abbreviate | omitted.

(Second Embodiment)
In the above, the charging / discharging of each storage battery 11 and 12 is individually controlled, so that the SOC of each storage battery 11 and 12 may vary. Moreover, in each of the storage batteries 11 and 12, the voltage which becomes overcharge (overdischarge) may differ. Therefore, when charging each of the storage batteries 11 and 12, in order to avoid that the SOC of one storage battery becomes an overcharged state (overdischarged state), if charging of the other storage battery is stopped, the other storage battery is still charged. Although it is possible, the state of charge can be limited.

  Therefore, in the second embodiment, on / off of the first switch unit 20 and the second switch unit 30 is controlled in accordance with the charging priority determined based on the current SOC of the lead storage battery 11 and the lithium ion storage battery 12. .

  In the present embodiment, in order to ensure the redundancy of power supply by the two power sources from each storage battery 11, 12 to the first electric load 14, as shown in FIG. 5, the switches 21, 22 of the first switch unit 20 Each is constituted by a parallel connection body of a plurality of semiconductor switches. That is, the switch 21 is configured by a parallel connection body of two semiconductor switches (switches 21a and 21b). The switch 22 is constituted by a parallel connection body of two semiconductor switches (switches 22a and 22b).

  In the above configuration, according to the charging priority of each storage battery 11, 12, each storage switch of the first switch unit 20 is individually turned on / off, so that the storage battery side with high charging priority is provided. The path resistance of the switch is made smaller than the path resistance of the switch on the storage battery side having a low charge priority. The “path resistance” shown in the present embodiment includes the ON resistance of each semiconductor switch, the wiring resistance of each electric path, and the like.

  Specifically, when both storage batteries 11 and 12 have the same charging priority, both switches 21a and 21b and both switches 22a and 22b are turned on. In this case, since the difference in path resistance between the storage batteries 11 and 12 is small, the charging current is supplied to both storage batteries 11 and 12 in the same manner.

  When the charging priority of the lithium ion storage battery 12 is higher than the lead storage battery 11, both the switches 22a and 22b are turned on, and only one of the switches 21a and 21b is turned on. In this case, since the path resistance of the switch 22 is smaller than the path resistance of the switch 21, the charging current is preferentially supplied to the lithium ion storage battery 12.

  Here, the priority of charging of each of the storage batteries 11 and 12 is determined by the control unit 40 using the relationship of FIGS. 6 and 7 stored in a ROM (not shown). FIG. 6 divides the SOC usage range of each of the storage batteries 11 and 12 into a plurality of sections. In this embodiment, the SOC of the lead storage battery 11 is divided into three, A1, B1, and C1 (A1> B1> C1). It is divided. Similarly, the SOC of the lithium ion storage battery 12 is divided into three parts A2, B2, and C2 (A2> B2> C2).

  Then, the control unit 40 associates the current SOC of each of the storage batteries 11 and 12 with each section of FIG. 6 and determines the priority of charging based on the relationship of FIG. Specifically, when the SOC of the lead storage battery 11 is A1, if the SOC of the lithium ion storage battery 12 is A2, it is determined that the priorities of the storage batteries 11 and 12 are the same. If the SOC of the lithium ion storage battery 12 is B2, C2, it is determined that the priority of the lithium ion storage battery 12 is high.

  When the SOC of the lead storage battery 11 is B1, if the SOC of the lithium ion storage battery 12 is A2, it is determined that the priority of the lead storage battery 11 is high. If the SOC of the lithium ion storage battery 12 is B2, it determines with the priority of both the storage batteries 11 and 12 being the same. If the SOC of the lithium ion storage battery 12 is C2, it is determined that the priority of the lithium ion storage battery 12 is high.

  When the SOC of the lead storage battery 11 is C1, if the SOC of the lithium ion storage battery 12 is A2 or B2, it is determined that the priority of the lead storage battery 11 is high. If the lithium ion storage battery 12 is C2, it will determine with the charge degree of both the storage batteries 11 and 12 being the same.

  As described above, by determining the priority of charging of the storage batteries 11 and 12 according to the SOC of each of the storage batteries 11 and 12, and controlling on / off of the first switch unit 20 according to the priority of the charging, Each storage battery 11 and 12 can be charged with good balance.

  Next, the charging control of the second embodiment by the control unit 40 will be described using the flowchart of FIG. The following processing is repeatedly performed by the control unit 40 at a predetermined cycle. Also in the present embodiment, the second switch unit 30 is basically maintained in the on state.

  In FIG. 8, it is determined whether or not each of the storage batteries 11 and 12 is being charged (S41). This process can be determined based on the detection results of the currents of the storage batteries 11 and 12. When an affirmative determination is made, it is determined whether the priority of charging of the lithium ion storage battery 12 is high (S42). If an affirmative determination is made in S42, both switches 22a and 22b are turned on, and switch 21a is turned off (switch 21b is turned on) (S43). In this case, the path resistance of the switch 22 is smaller than that of the switch 21, and the lithium ion storage battery 12 is charged with priority.

  When a negative determination is made in S42, that is, when the charge priority of the lead storage battery 11 and the lithium ion storage battery 12 is the same, all the switches 21 and 22 are turned on (S44). In this case, the difference in path resistance between the first switch unit 20 and the second switch unit 30 is suppressed, and the charging current is supplied to both the storage batteries 11 and 12 in the same manner. When a negative determination is made in S41, that is, when it is not during charging, the normal control of FIG. 4 is performed (S45).

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

  When the switch 21 and the switch 22 are configured by a parallel connection body of a plurality of semiconductor switches, by switching which semiconductor switch is turned on among the semiconductor switches of the parallel connection body, the switches 21 and 22 The path resistance can be changed. By utilizing this, the storage batteries 11 and 12 can be charged according to the charging priority by switching the semiconductor switch on and off according to the charging priority.

  -By determining the priority of charging of the lead storage battery 11 and the lithium ion storage battery 12 according to the state of charge of the lead storage battery 11 and the lithium ion storage battery 12, using this, the first switch unit 20 and the second switch The state of the unit 30 can be switched.

(Third embodiment)
When two lead storage batteries 11 and lithium ion storage batteries 12 having different battery characteristics are used, it is considered that the upper limit value (upper limit voltage) of the usable open-circuit voltage OCV may be different between the storage batteries 11 and 12. In this case, when both the storage batteries 11 and 12 are charged at the same time, if the voltage of one storage battery reaches the upper limit voltage, the charging is stopped while the other storage battery is still chargeable. Moreover, even if the voltage of one storage battery becomes an upper limit voltage, when charging of the other storage battery is continued, there is an inconvenience that the voltage of one storage battery exceeds the upper limit voltage and an overcharged state is applied. Can occur.

  Therefore, in the third embodiment, when the upper limit voltages of the storage batteries 11 and 12 are different, when charging the storage batteries 11 and 12, until the voltage of one of the storage batteries on the lower upper limit voltage reaches the upper limit voltage, Charging both storage batteries 11 and 12 is performed. And when the voltage of one storage battery with a low upper limit voltage reaches an upper limit voltage, the other storage battery with a higher upper limit voltage is charged with priority.

  Moreover, when charging both the storage batteries 11 and 12, if each storage battery 11 and 12 is a low temperature state, since internal resistance of a battery is large and a voltage will rise easily with charge, it will become easy to reach an upper limit voltage. Therefore, in the third embodiment, in the case of a low temperature state where the temperature of each of the storage batteries 11 and 12 is less than a predetermined value, the storage battery on the side with the higher upper limit voltage is limited in a state where charging of the storage battery on the side with the lower upper limit voltage is restricted. Charge. Specifically, the storage battery having the lower upper limit voltage is charged via a diode. In this case, charging of the storage battery having a high upper limit voltage can be continued while suppressing the voltage increase of the storage battery having a lower upper limit voltage. In addition, it is expected that the rise in the voltage of the storage battery is suppressed by the heat generated by energization of the diode that promotes the rise in the temperature of the storage battery.

  Next, the charging control of the third embodiment by the control unit 40 will be described. FIG. 9 is an example of a processing procedure when the upper limit voltage V2 of the lithium ion storage battery 12 is larger than the upper limit voltage V1 of the lead storage battery 11 (when V1 <V2). The processing in FIG. 9 is based on the configuration in FIG. Also in the present embodiment, the second switch unit 30 is basically maintained in an on state, and the on / off of the first switch unit 20 is controlled so that the storage batteries 11 and 12 are charged by the generated power of the rotating electrical machine 10. Switch the state.

  First, it is determined whether or not each storage battery 11, 12 is being charged (S51). If it is determined that the battery is being charged in S51, it is determined whether or not the voltage (Pb voltage) of the lead storage battery 11 is equal to or higher than the upper limit voltage V1 (S52).

  When the voltage (Pb voltage) of the lead storage battery 11 is equal to or higher than the upper limit voltage V1, the switch 21 is turned off and the switch 22 is turned on (S53). In this case, charging of the lithium ion storage battery 12 can be continued in a state where the charging of the lead storage battery 11 is stopped and the voltage increase of the lead storage battery 11 is stopped. When the voltage (Pb voltage) of the lead storage battery 11 is less than the upper limit voltage V1, it is determined whether or not the temperature of the lead storage battery 11 is less than a predetermined value (low temperature) (S54). This process is determined based on, for example, a temperature detection value by a temperature sensor (not shown) of the lead storage battery 11.

  When the temperature of the lead storage battery 11 is low, the switch 21 is turned on and the switch 22 is turned off (S55). In this case, the charging of the lithium ion storage battery 12 can be continued in a state where the conduction of the charging current to the lead storage battery 11 is restricted by the diode D2 of the switch 22 and the voltage increase of the lead storage battery 11 is suppressed to the current flowing through the diode D2. .

  If the lead storage battery 11 is not at a low temperature, both the switches 21 and 22 are turned on, and both the storage batteries 11 and 12 are similarly charged with the generated power of the rotating electrical machine 10 (S56). If a negative determination is made in S51, the above-described normal processing is performed (S57). In the present embodiment, it is possible to maintain power supply redundancy with the two power sources for the first electrical load 14 regardless of whether the switches 21 and 22 are turned on or off.

  Next, a processing procedure when the upper limit voltage V2 of the lithium ion storage battery 12 is smaller than the upper limit voltage V1 of the lead storage battery 11 (V1> V2) will be described with reference to FIGS. FIG. 10 shows a configuration in which a rotating electrical machine 10a is connected to the first terminal T1 side instead of the rotating electrical machine 10 connected to the second terminal T2 side in FIG. For example, an alternator or the like is used for the rotating electrical machine 10a. Therefore, at the time of charging with the generated power of the rotating electrical machine 10, the charging current from the rotating electrical machine 10 a is supplied to the lead storage battery 11 regardless of whether the first switch unit 20 is on or off. On the other hand, the charge state of the lithium ion storage battery 12 is switched by switching the first switch unit 20 on and off. In the present embodiment, this is used to switch the charging priority of the storage batteries 11 and 12.

  In addition, in FIG. 10, although the structure of the 2nd switch part 30 is abbreviate | omitted, the 2nd switch part 30 is provided in the lithium ion storage battery 12 side, and it is basically maintained in an ON state similarly to the above-mentioned case. It may be.

  In FIG. 11, it is determined whether or not each of the storage batteries 11 and 12 is being charged (S61). If it is determined in S61 that the battery is being charged, it is determined whether or not the voltage (Li voltage) of the lithium ion storage battery 12 is equal to or higher than the upper limit voltage V2 (S62). When the voltage (Li voltage) of the lithium ion storage battery 12 is equal to or higher than the upper limit voltage V2, the switch 21 is turned on and the switch 22 is turned off (S63). In this case, the charging of the lithium ion storage battery 12 is stopped by the switch 22 being off. Thereby, in the state which stopped the voltage rise of the lithium ion storage battery 12, charge of the lead storage battery 11 can be continued.

  When a negative determination is made in S62, it is determined whether or not the temperature of the lithium ion storage battery 12 having a low upper limit voltage is lower than a predetermined value (low temperature) (S64). This process is determined based on, for example, a temperature detection value by a temperature sensor (not shown) of the lithium ion storage battery 12.

  When the lithium ion storage battery 12 is at a low temperature, the switch 21 is turned off and the switch 22 is turned on (S65). In this case, the charging of the charging current to the lithium ion storage battery 12 is restricted by the diode D1 of the switch 21, and charging of the lead storage battery 11 can be continued in a state in which the voltage increase of the lithium ion storage battery 12 is suppressed.

  When the lithium ion storage battery 12 is not at a low temperature, both the switches 21 and 22 are turned on, and both storage batteries 11 and 12 are similarly charged with the generated power of the rotating electrical machine 10 (S66). If it is determined in S61 that it is not during charging, the above-described normal processing is performed (S67). In the present embodiment, it is possible to maintain power supply redundancy with the two power sources for the first electrical load 14 regardless of whether the switches 21 and 22 are turned on or off.

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

  -When the upper limit voltages of the lead storage battery 11 and the lithium ion storage battery 12 are different, when charging each of the storage batteries 11, 12, the storage batteries 11, 12 are charged until the storage battery on the side with the lower upper limit voltage reaches the upper limit voltage. To do. And when the storage battery with the lower upper limit voltage reaches the upper limit voltage, the other storage battery with the higher upper limit voltage is preferentially charged. In this case, it is possible to charge the storage batteries 11 and 12 closer to the fully charged state while avoiding an overvoltage state in which a voltage higher than the upper limit voltage is applied to the storage batteries 11 and 12.

  -When the temperature on the side of the storage battery having a low upper limit voltage is lower than a predetermined temperature, the voltage increase accompanying charging in the storage battery is large, and the upper limit voltage is easily reached. Therefore, by turning off the switch on the side of the storage battery with the lower upper limit voltage and turning on the switch on the side of the storage battery with the higher upper limit voltage, charging is performed via a diode on the side of the storage battery with the lower upper limit voltage turned off. As a result, an increase in charging voltage can be suppressed. And in the storage battery side by the side with a high upper limit voltage, it can charge more appropriately by suppressing the voltage rise of the storage battery by the side of the storage battery with a low upper limit voltage. Further, on the side of the storage battery having a lower upper limit voltage, the temperature increase caused by energization through the diodes promotes the temperature increase of the storage battery, and the voltage increase of the storage battery can be suppressed.

  -When the voltage on the storage battery side with the lower upper limit voltage reaches the upper limit voltage, the switch on the storage battery side with the lower upper limit voltage is turned off and the switch on the storage battery side with the higher upper limit voltage is turned on. In a state where charging of the low storage battery is stopped, the storage battery side having a high upper limit voltage can be charged.

(Fourth embodiment)
FIG. 12 is an electric circuit diagram of the power supply system in the present embodiment. In FIG. 12, as a difference from FIG. 1 described above, two connection paths L1 and L11 are provided in parallel between the first terminal T1 and the second terminal T2, which are high-current input / output terminals, of which connection The first switch unit 20 is provided in the path L1, and the third switch unit 60 is provided in the connection path L11 as a parallel path. The first switch unit 20 is the opening / closing means described above. The third switch unit 60 is an opening / closing means provided in parallel with the first switch unit 20 between the lead storage battery 11 and the lithium ion storage battery 12.

  The third switch unit 60 includes a series connection body of two semiconductor switches 61. Each of these switches 61 is made of, for example, an N-channel MOSFET, and their source terminals are connected to face each other. Thus, the anodes of the diodes face each other in each switch 61. This is the same configuration as the second switch unit 30.

  Here, the connection paths L1 and L11 are both electrical paths provided between the terminals T1 and T2, but the connection path L1 is provided as a load power feeding path for passing a current according to the required power of the first electrical load 14. The connection path L11 is provided as a large current path that allows energization of a larger current than the load power supply path. The connection path L11 is also a large current path for energizing a large current mainly including input / output of the rotating electrical machine 10. In this case, the first switch unit 20 and the third switch unit 60 have different numbers of semiconductor switches, and the third switch unit 60 through which a large current flows has a number of switches that is lower than that of the first switch unit 20 having a lower current. It is increasing. For example, in the first switch unit 20, two series connection bodies of two semiconductor switches are provided in parallel, whereas in the third switch unit 60, three series connection bodies of two semiconductor switches are provided in parallel. ing. Incidentally, in the second switch unit 30 on the lithium ion storage battery 12 side, the same number of semiconductor switches as the third switch unit 60 are provided.

  The control unit 40 controls on / off of the switch units 20, 30, 60 in the battery unit U based on the vehicle operating state and the state of the storage batteries 11, 12. Below, switch control by the control part 40 is demonstrated concretely. In the switch unit 20, the switches 21 and 22 of the series connection body are individually turned on / off. Moreover, in the switch part 30, each switch 31 of a serial connection body is collectively ON / OFF controlled, and in the switch part 60, each switch 61 of a serial connection body is collectively ON / OFF controlled.

  Here, (1) at the time of deceleration regeneration, (2) at the time of powering driving of the rotating electrical machine 10, that is, at the time of power assist and restart, (3) at the time of priority discharge of the lead storage battery 11, (4) priority of the lithium ion storage battery 12 The state of energization will be described with reference to FIGS. 13 to 17 at the time of discharging, (5) when the use of the lithium ion storage battery 12 is stopped, that is, when charging / discharging is prohibited.

  During the deceleration regeneration shown in FIG. 13, the switches 21, 22, 31, 61 are controlled in a state of [ON, ON, ON, ON]. In this case, the electric power generated by the rotating electrical machine 10 is supplied to the storage batteries 11 and 12 via the switches 31 and 61, and the storage batteries 11 and 12 are appropriately charged. Further, the generated electric power of the rotating electrical machine 10 is supplied to the first electric load 14 via the switch 22 in accordance with the required power (power consumption) of the first electric load 14.

  Power supply to the first electrical load 14 may be performed via either of the switches 21 and 22. When the switches 21 and 22 are both on, the generated electric power of the rotating electrical machine 10 is supplied to the first electrical load 14 via the switch 21. It may be supplied to the load 14. In addition, the structure which turns ON only one of the switches 21 and 22 at the time of deceleration regeneration may be sufficient.

  At the time of powering driving of the rotating electrical machine 10 shown in FIG. 14, the switches 21, 22, 31, 61 are controlled in a state of [ON, OFF, ON, OFF]. In this case, electric power is supplied from the lead storage battery 11 to the first electrical load 14 via the switch 21. Further, electric power is supplied from the lithium ion storage battery 12 to the rotating electrical machine 10 via the switch 31.

  At the time of priority discharge of the lead storage battery 11 shown in FIG. 15, the switches 21, 22, 31, 61 are controlled in a state of [ON, OFF, ON, OFF]. In this case, electric power is preferentially supplied from the lead storage battery 11 to the first electric load 14 via the switch 21.

  At the time of priority discharge of the lithium ion storage battery 12 shown in FIG. 16, the switches 21, 22, 31, 61 are controlled in a state of [OFF, ON, ON, OFF]. In this case, power is preferentially supplied from the lithium ion storage battery 12 to the first electrical load 14 via the switch 22.

  When the use of the lithium ion storage battery 12 shown in FIG. 17 is stopped, the switches 21, 22, 31, and 61 are controlled in a state of [ON, ON, OFF, ON]. In this case, the electric power generated by the rotating electrical machine 10 is supplied to the lead storage battery 11 via the switch 61, and only the lead storage battery 11 is appropriately charged. Further, the generated electric power of the rotating electrical machine 10 is supplied to the first electric load 14 via the switch 22 in accordance with the required electric power of the first electric load 14.

  Power supply to the first electrical load 14 may be performed via either of the switches 21 and 22. When the switches 21 and 22 are both on, the generated electric power of the rotating electrical machine 10 is supplied to the first electrical load 14 via the switch 21. It may be supplied to the load 14. Note that only one of the switches 21 and 22 may be turned on.

  Further, in the battery unit U, there is a concern that a failure may occur in each switch unit. Below, the fail safe process implemented by the control part 40 at the time of occurrence of a switch failure is demonstrated. In this case, the control unit 40 constitutes a failure determination unit and a fail-safe unit. The control unit 40 determines whether or not there is a failure in any of the switches 21 and 22 of the first switch unit 20 and any of the switches 21 and 22. If it is determined that one of the switches 21, 22 is turned on, the switch that is not broken is turned on, and the third switch unit 60 is turned on. For example, the control unit 40 acquires the voltage across the switch when each of the switches 21 and 22 is on and off, and determines whether there is a failure in each of the switches 21 and 22 based on the voltage across the switches. When the battery unit U fails, the second switch unit 30 connected to the lithium ion storage battery 12 is maintained in the off state.

  In this case, when the switch 21 fails, the fail-safe 1 process shown in FIG. 18 is performed, when the switch 22 fails, the fail-safe 2 process shown in FIG. 19 is executed, and when the switch 61 fails, the process shown in FIG. The process of the fail safe 3 shown is implemented.

  When the switch 21 shown in FIG. 18 fails, the switches 22 and 61 are controlled in the [ON, ON] state. In this case, the electric power generated by the rotating electrical machine 10 is supplied to the lead storage battery 11 via the switch 61, and the lead storage battery 11 is appropriately charged. Further, the electric power generated by the rotating electrical machine 10 is supplied to the first electric load 14 via the switch 22.

  When the switch 22 shown in FIG. 19 fails, the switches 21 and 61 are controlled in the [ON, ON] state. In this case, the electric power generated by the rotating electrical machine 10 is supplied to the lead storage battery 11 via the switch 61, and the lead storage battery 11 is appropriately charged. Further, the electric power generated by the rotating electrical machine 10 is supplied to the first electric load 14 via the switch 21.

  When the switch 61 shown in FIG. 20 fails, the switches 21 and 22 are controlled in the [ON, ON] state. In this case, the electric power generated by the rotating electrical machine 10 is supplied to the lead storage battery 11 via the switches 21 and 22, and the lead storage battery 11 is appropriately charged. Further, the electric power generated by the rotating electrical machine 10 is supplied to the first electric load 14 via the switch 22.

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

  A charging path for supplying the generated power of the rotating electrical machine 10 to the lead storage battery 11 via the third switch unit 60 by turning on (closing) the third switch unit 60 during charging by the power generation of the rotating electrical machine 10. Can be formed. In this case, between the lead storage battery 11 and the lithium ion storage battery 12, a charging path to the lead storage battery 11 and a power supply path to the first electric load 14 are formed in parallel. As a result, the current load of each of the switches 21 and 22 constituting the first switch unit 20 is sufficient to satisfy the required power of the first electric load 14. In other words, by forming the charging path to the lead storage battery 11 and the power feeding path to the first electric load 14, it is possible to realize an appropriate circuit configuration in consideration of the magnitude of the assumed power in each path. it can.

  Since the load power supply path (L1) and the large current path (L11) are provided in parallel between the lead storage battery 11 and the lithium ion storage battery 12, the first switch unit 20 in the load power supply path among these paths While the number of switches 21 and 22 constituting each of the switches is reduced, it is possible to cope with the large current path by increasing the number of switches of the third switch unit 60.

  If a rotating electrical machine 10 having a large rated output is used, the assumed maximum power in the large current path is increased according to the rated output. It is not necessary to increase the number of switches 21 and 22, respectively, and this can be dealt with only by handling the third switch unit 60 on the large current path side.

  When charging / discharging the lithium ion storage battery 12 is prohibited, at least one of the switches 21 and 22 is turned on, the second switch unit 30 is turned off, and the third switch unit 60 is turned on. Thereby, in a state where charging / discharging of the lithium ion storage battery 12 is prohibited, the lead electrical storage battery 11 can be charged by the rotating electrical machine 10 and the power supply to the first electric load 14 can be continuously performed.

  -When each switch 21 and 22 of the 1st switch part 20 fails, it was set as the structure which turns on the switch which is not out of the switches 21 and 22 and turns on the 3rd switch part 60. Thereby, even when there is a switch failure, the lead electrical storage battery 11 can be charged by the rotating electrical machine 10 and power supply to the first electrical load 14 can be continued. Thereby, an appropriate fail-safe treatment can be performed.

(Other embodiments)
-In above-mentioned 1st Embodiment, in the electrical pathway between the lead storage battery 11 and the lithium ion storage battery 12, the rotary electric machine 10 (ISG as a generator) is formed in the lithium ion storage battery 12 side among the both sides of the 1st switch part 20. Etc.), but this configuration may be changed. For example, as shown in FIG. 10, it is good also as a structure which connects the rotary electric machine 10a as a generator to the lead acid battery 11 side. In this case, when a ground fault occurs on the lead storage battery 11 side, even if the discharge from the lead storage battery 11 to the first electrical load 14 is stopped by turning off the switch 21 and turning on the switch 22, The lithium ion storage battery 12 can be discharged to the first electric load 14. Similarly, when a ground fault occurs on the lithium ion storage battery 12 side, even if the discharge from the lithium ion storage battery 12 to the first electrical load 14 is stopped by turning the switch 21 on and the switch 22 off, The lead storage battery 11 can be discharged to the first electrical load 14.

  -In said 1st Embodiment, when a ground fault arises, the switch 21 or switch 22 by the side of the storage battery in which the ground fault has not occurred is turned on, and the discharge to the 1st electric load 14 is continued. However, as described above, when the cathodes of the diodes D1 and D2 of the first switch unit 20 are connected to face each other, even if the switches 21 and 22 on the storage battery side where no ground fault has occurred are turned off, The discharge to the first electrical load 14 can be continued by energization via the diodes of the switches 21 and 22.

  The above second embodiment can also be applied to the configuration of the battery system of FIG. 10 in which the battery unit U includes only the first terminal T1 and the third terminal T3 as external terminals. Also in this case, each switch 21, 22 is constituted by a parallel connection body of a plurality of switches, and the on / off of each switch 21, 22 is switched so that the path resistance is switched according to the priority of charging of the storage batteries 11, 12. It only has to be done.

  In the second embodiment, each of the switches 21 and 22 of the first switch unit 20 is configured as a parallel connection body of two semiconductor switches. However, the number of the switches 21 and 22 is n (n = 2, 2). 3, 4, etc.) may be configured as a parallel connection body of switches.

  -In said 2nd Embodiment, you may comprise the 2nd switch part 30 as a parallel connection body of the n switches (n = 2, 3, 4, ...). In this case, on / off of both the first switch unit 20 and the second switch unit 30 is controlled in accordance with the charging priority of the storage batteries 11 and 12. Thereby, each storage battery 11 and 12 can be charged according to the priority of charge by changing the wiring resistance of each switch 20 and 30. FIG.

  -In said 3rd Embodiment, in each processing of Drawing 9 and Drawing 11, it is judged whether lead storage battery 11 (or lithium ion storage battery 12) is low temperature, and lead storage battery 11 (or lithium ion storage battery 12). ) Is both determined as to whether or not the voltage is equal to or higher than a predetermined threshold, but only one of the determination processes may be performed.

  -In the above, the battery unit U may contain only the 1st switch part 20 and the connection point P1, and is not limited to the said structure.

  -In the power supply system (configuration of FIG. 12) of said 4th Embodiment, control based on a ground fault determination (FIG. 3), switch control based on the priority of charge (FIGS. 5-8), each storage battery 11, The charging control based on the upper limit voltage of 12 and the temperature (FIGS. 9 to 11) can be implemented in appropriate combination.

  In the fourth embodiment, the specific configuration of the third switch unit 60 may be changed. For example, in the two switches 61, the anodes of the diodes do not have to face each other. A semiconductor switch other than the N-channel MOSFET may be used.

  DESCRIPTION OF SYMBOLS 10 ... Rotary electric machine, 11 ... Lead storage battery, 12 ... Lithium ion storage battery, 20 ... 1st switch part, 21 ... Switch, 22 ... Switch, P1 ... Connection point.

Claims (20)

Applied to a power supply system comprising a first storage battery (11) and a second storage battery (12) connected in parallel to a rotating electrical machine (10) having a power generation function,
A series connection body of a first switch (21) and a second switch (22) connected to the electric path (L1) between the first storage battery and the second storage battery with the forward directions of the diode components facing each other. ,
A connection point (P1) that is an intermediate point between the first switch and the second switch and connects an electrical load (14);
A power supply device comprising:   The power supply device according to claim 1, further comprising switch control means (40) for individually turning on and off the first switch and the second switch.   3. The power supply device according to claim 2, wherein the switch control unit turns on a switch on a storage battery side that prioritizes discharge to the electric load among the storage batteries, and turns off a switch on a storage battery side that does not give priority to discharge to the electric load. . The rotating electrical machine is capable of powering drive, and is connected between a series connection body of the first switch and the second switch and the second storage battery,
4. The power supply device according to claim 2, wherein the switch control unit turns on the first switch and turns off the second switch in a state where the rotating electrical machine is driven by powering. 5. The rotating electrical machine is connected between a series connection body of the first switch and the second switch and the second storage battery,
5. The power supply device according to claim 2, wherein the switch control unit turns on both the first switch and the second switch during charging by power generation of the rotating electrical machine. Opening and closing means (60) provided in parallel with the series connection body between the first storage battery and the second storage battery,
5. The switch control unit according to claim 2, wherein the switch control unit turns on at least one of the first switch and the second switch and turns on the opening / closing unit during charging by power generation of the rotating electrical machine. Power supply.   Between the first storage battery and the second storage battery, the electrical path in which the series connection body is provided is a load power supply path through which a current corresponding to the required power of the electrical load flows, and the opening / closing means is provided in parallel. The power supply device according to claim 6, wherein the path (L11) is a large current path that allows energization of a larger current than the load power supply path. Failure determination means (40) for determining presence or absence of failure in any of the first switch and the second switch;
When it is determined that one of the first switch and the second switch has failed, the switch that has not failed among the first switch and the second switch is turned on, and the opening / closing means is turned on. Fail-safe means (40);
The power supply device according to claim 6 or 7. A ground fault determining means (40) for determining the presence or absence of a ground fault in the electrical path for electrically connecting the first storage battery and the second storage battery;
The switch control means turns off the first switch when a ground fault occurs on the first storage battery side with respect to the first switch, and a ground fault occurs on the second storage battery side with respect to the second switch. The power supply device according to any one of claims 2 to 8, wherein the second switch is turned off in the event of a failure. Each of the first switch and the second switch is constituted by a parallel connection body of a plurality of semiconductor switches,
The switch control means switches which one of the plurality of semiconductor switches is turned on in the first switch and the second switch according to a priority of charging of the first storage battery and the second storage battery. The power supply device according to any one of 2 to 9. Each of the first storage battery and the second storage battery has a different upper limit voltage,
In the charging of the first storage battery and the second storage battery, the switch control means charges both the first storage battery and the second storage battery until one of the storage batteries on the lower side of the upper limit voltage reaches the upper limit voltage. And after the one storage battery reaches the upper limit voltage, the on / off of the first switch and the second switch is controlled so as to preferentially charge the other storage battery on the higher upper limit voltage side. The power supply device according to any one of 2 to 10. Each of the first storage battery and the second storage battery has a different upper limit voltage,
The switch control means turns off the switch of the storage battery having the lower upper limit voltage and turns off the switch of the storage battery having the higher upper limit voltage when the temperature of the storage battery having the lower upper limit voltage is lower than a predetermined value. The power supply device according to claim 2, which is turned on.   The switch control means turns off the switch of the storage battery having the lower upper limit voltage when the voltage of the storage battery having the lower upper limit voltage of the first storage battery and the second storage battery reaches the upper limit voltage. The power supply device according to claim 12, wherein a switch on a storage battery side having a high upper limit voltage is turned on. A second opening / closing means (30) connected to the series connection body of the first switch and the second switch and connected in series to the second storage battery;
The switch control means turns on the second opening / closing means when permitting charging / discharging by the second storage battery, and turns off the second opening / closing means when prohibiting charging / discharging of the second storage battery. The power supply device according to any one of claims 2 to 13.   The power supply apparatus according to claim 14, wherein the second opening / closing means includes a series connection body of a third switch (31a) and a fourth switch (31b) in which the forward directions of the diode components are connected in reverse.   The switch control means turns on at least one of the first switch and the second switch, turns off the second opening / closing means, and turns off the first storage battery and the second switch when charging / discharging of the second storage battery is prohibited. The power supply device according to claim 14 or 15, wherein the switching means (60) provided in parallel with the series connection body between the storage batteries is turned on.   The first storage battery is connected to a second electric load (13) having a required power larger than that of the electric load without going through a series connection body of the first switch and the second switch. The power supply device according to any one of the above. The second electric load is a starter device for starting the engine;
The power supply device according to claim 17, wherein a storage capacity of the first storage battery is larger than a storage capacity of the second storage battery.   The power supply device according to any one of claims 1 to 18, wherein a charge / discharge performance of the second storage battery is higher than a charge / discharge performance of the first storage battery.   The priority determination means (40) which determines the priority of charge of a said 1st storage battery and a 2nd storage battery by comparison with the charge state of a said 1st storage battery and the charge state of a said 2nd storage battery is Claim 1 thru | or. 20. The power supply device according to any one of items 19.

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