JP6546422B2 - Battery system controller - Google Patents

Description

  The present invention relates to a battery system control apparatus, and more particularly to a battery system control apparatus for controlling current supply in a battery system including a main battery and a sub-battery provided as an auxiliary to the main battery.

  A car equipped with an internal combustion engine such as a general gasoline engine, a hybrid car where the engine and motor run in cooperation with each other, supplies electric power to the motor and various electric loads and recharges it. It is equipped with a rechargeable secondary battery (battery).

  By the way, the above-mentioned motor vehicle mounts various electrical components as an electric load, There existed a case where these electrical components could not be operated effectively only with one battery.

  Therefore, in addition to a main battery (for example, a lead storage battery etc.) for driving a motor etc., a sub-battery (for example a lithium ion battery or a nickel hydrogen battery (Ni-MH) etc.) for operating various electric components is mounted A battery system has been developed in which both batteries share the power supply to the electrical load.

  Various techniques have been proposed for a battery system control apparatus that controls current supply in a battery system including such a main battery and a sub-battery (for example, Patent Document 1 etc.).

JP 2012-80706 A

  By the way, at the time of restart of a vehicle (for example, at the time of restart of the engine after the end of idling stop, etc.), a voltage drop may occur due to driving of a device such as a starter motor requiring relatively electric power.

  Therefore, the conventional battery system control device is affected by the general load (for example, various lamps, wipers, blower fan, heater for defroster, etc.) having little influence even if the above voltage drop occurs, and the voltage is stable. It divides into the stabilization load (for example, various audio equipment, navigation apparatus, etc.) which needs to be integrated, and is electrically separated and controlled by the switching means (opening / closing means) with which a control device is equipped.

  Here, by supplying the power of the sub-battery charged with the power generated by the regenerative energy to the stabilization load during traveling, the power generation load of the generator can be reduced, and the fuel consumption can be improved.

  However, in the conventional battery system control device, when power from the sub-battery is supplied to a part of the general load to more effectively discharge the power generated by the regenerative energy, It is necessary to separately provide a dedicated changeover switch.

  In addition, when the ignition switch is off, it is necessary to supply a dark current (standby current) to a part of the electric loads. Here, depending on circumstances such as the capacity of the sub-battery and the internal configuration, there is a demand to supply dark current to the stabilized load from the main battery.

  In order to respond to such a request, it is necessary to add a normally closed mechanical relay or the like so that the dark current can be supplied to the stabilized load from the main battery as well, and the number of parts increases. There was a problem that the device became large.

  Note that "dark current" refers to the current flowing in various circuits in a vehicle with the ignition switch turned off. In addition, as a part of the electric loads that need to be supplied with dark current, for example, a microcomputer that configures an electronic control unit (ECU), a watch, a security system, and the like can be given.

  The present invention has been made in view of the above problems, and in a battery system having a main battery and a sub battery, power can be supplied from the sub battery to a part of general loads without increasing the number of parts. Another object of the present invention is to provide a battery system control device capable of supplying dark current from a main battery to a stabilized load.

In order to achieve the above object, a battery system control apparatus according to claim 1 is driven by an output shaft of an engine mounted on a vehicle to generate electric power, and an electric generator that generates electric power by regenerative energy, the electric generator and the electric power. An electric load connected in parallel in parallel, a main battery electrically connected in parallel with the generator, and capable of charging the generated power of the generator, and electrically connected in parallel with the generator and the main battery; A sub-battery comprising a relay capable of charging power generated by a generator, having a higher output and higher energy density than the main battery, and turning on / off a discharge current, the generator, the electric load, and the main battery And an electrical connection between the generator, the electrical load, the main battery and the sub-battery, which is electrically connected to the sub-battery And a control means for controlling the on / off of the relay and the opening / closing of the on / off switch, wherein the electric load is the main battery or the sub battery when the ignition switch of the vehicle is off. The first general load and the second general load including the dark current required load requiring the supply of dark current from the battery, and the stabilization load receiving the stabilized voltage supply from the sub-battery are separately arranged. The second general load includes a dark current required load that requires supply of dark current from the main battery or the sub-battery when the ignition switch of the vehicle is off, and the open / close switch includes the first general load A first open / close switch for switching on / off between the second general load and the second general load, and the second general load A second on-off switch for switching between conduction and disconnection with the stabilization load, and the first on-off switch and the second on-off switch include the main battery and the sub-battery Are electrically connected in series.

  The battery system control device according to claim 2 relates to the invention according to claim 1, wherein the first open / close switch is a first FET serving as a forward switch for current from the generator or the main battery, and And a first gate driver connected between the gate electrode of the first FET and the control means, wherein the second open / close switch is a forward switch for the current from the generator or the main battery A second FET and a second gate driver connected between the gate electrode of the second FET and the control means, and the drain electrode of the first FET and the second It is characterized in that it is connected to the source electrode of the FET.

  The battery system control device according to claim 3 further comprises a voltage detection unit for detecting the voltage of the first FET and the second FET according to the invention described in claim 2, and the control means The first FET and the second FET are controlled to be switched on / off based on the voltage detected by the detection unit.

  In the battery system control device according to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the voltage of the sub battery is equal to or higher than the voltage of the main battery. It is characterized in that it is selected to be

  According to the present invention, in a battery system equipped with a main battery and a sub-battery, power can be supplied from the sub-battery to a part of general loads without increasing the number of parts, and to a stabilized load. A battery system controller capable of supplying dark current from a main battery can be provided.

FIG. 1 is a circuit diagram showing an example of a circuit configuration of a battery system control device according to a first embodiment. It is an explanatory view showing the current distribution state at the time of OFF of the ignition switch of a battery system control device concerning a 1st embodiment. FIG. 7 is an explanatory view showing a current distribution state when the vehicle restart is performed in the battery system control device according to the first embodiment. The battery system control apparatus which concerns on 1st Embodiment WHEREIN: It is explanatory drawing which shows the electric current distribution state in the case of charging during vehicle travel. FIG. 6 is an explanatory view showing a current distribution state in the case of discharging the sub-battery while the vehicle is traveling in the battery system control device according to the first embodiment. It is a circuit diagram which shows the example of a circuit structure of the battery system control apparatus which concerns on 2nd Embodiment.

First Embodiment
A first embodiment of the present invention will be described with reference to FIGS.

(Configuration Example of Battery System Control Device According to First Embodiment)
FIG. 1 is a circuit diagram showing an example of a circuit configuration of a battery system control apparatus 1A according to the first embodiment.

  As shown in FIG. 1, the battery system control device 1A includes an alternator (ALT) 11 as a generator, an electric load L (L1a, L1b, L2) electrically connected in parallel with the alternator 11, and an engine (figure (Not shown), a starter battery (ST) 12 and a main battery (starting battery) B1 electrically connected in parallel to the alternator 11 and capable of charging electric power generated by the alternator 11, and the alternator 11 and the main battery B1. Control means (switching control circuit) comprising a sub battery (voltage stabilization sub battery) B2 electrically connected in parallel, an open / close switch SW1, SW2, a microcomputer for controlling opening / closing of the open / close switch SW1, SW2 ) And 10).

  The alternator 11 is driven by the output shaft of an engine mounted on a vehicle to generate electric power, and is configured to generate electric power by regenerative energy generated at the time of braking (during deceleration).

  The main battery B1 is configured of, for example, a lead storage battery.

  The sub-battery B2 can charge the power generated by the alternator 11, and is configured of a battery having a higher output and higher energy density than the main battery B1, such as a lithium ion battery or a nickel hydrogen battery (Ni-MH).

  The voltage of the lead storage battery constituting the main battery B1 is generally 12 V, and the voltage of the sub battery B2 is set to a voltage of about 12 V or higher.

  Further, as shown in FIG. 1, the sub-battery B2 is provided with a relay (breakdown relay) 50 on the positive electrode side to turn on / off the discharge current. The relay 50 is connected to the switching control circuit 10 and turned on / off by the control of the switching control circuit 10.

  The alternator 11 and the starter motor 12 are connected to the plus electrode of the main battery B1 via the nodes n1 and n2. The alternator 11, the starter motor 12, and the negative electrode of the main battery B1 are grounded via a vehicle body or the like.

  The electric load L includes the first general load L1a and the second general load L1b including the dark current required load that requires the supply of dark current from the main battery B1 or the sub battery B2 when the ignition switch provided in the vehicle is off. The load is divided into a stabilized load L2 that receives supply of a stabilized voltage from the battery B2.

  More specifically, the first general load L1a is electrically connected in parallel via the node n3, the second general load L1b is electrically parallel via the node n9, and the stabilized load L2 is electrically connected via the node n13. .

  The open / close switches SW1 and SW2 are electrically connected to the alternator 11, the electric loads L (L1a, L1b and L2), the main battery B1 and the sub-battery B2, and the alternator 11 and the electric loads L (L1a, L1b and L2), It is comprised by the switching element (1st FET (Field effect transistor) (FET1), 2nd FET (FET2)) which switches electricity supply and interruption | blocking between the main battery B1 and the sub battery B2.

  More specifically, as shown in FIG. 1, the FET 1 constituting the first open / close switch SW1 is arranged to constitute a forward switch for the current from the alternator 11 or the main battery B1, and the nodes n4 to n6 , And is connected in series between the first general load L1a and the second general load L1b. The diode D1 represents a parasitic diode (body diode) of the FET1.

  Further, the gate electrode of the FET 1 is connected to the switching control circuit 10 via the first gate driver G1. The other electrode of the first gate driver G1 is connected to the drain electrode side of the FET 1 via the node n7.

  As a result, the FET 1 constituting the first open / close switch SW1 can switch between conduction and disconnection between the first general load L1a and the second general load L1b under the control of the switching control circuit 10.

  On the other hand, the FET 2 constituting the second open / close switch SW2 is arranged to constitute a forward switch for the current from the alternator 11 or the main battery B1, and via the nodes n10 to n12, the second general load L1b and It is connected in series with the stabilizing load L2. The diode D2 represents a parasitic diode (body diode) of the FET2.

  Further, the gate electrode of the FET 2 is connected to the switching control circuit 10 via the second gate driver G2. The other electrode of the second gate driver G2 is connected to the source electrode side of the FET 2 via the node n8.

  Thus, the FET 2 constituting the second on-off switch SW2 can switch between conduction and disconnection between the second general load L1 b and the stabilization load L2 under the control of the switching control circuit 10.

  Further, the positive electrode of the sub-battery B2 is connected to the stabilized load L2 and the drain electrode side of the FET 2 through the node n13. The negative electrode of the sub battery B2 is grounded via a vehicle body or the like.

  In the circuit shown in FIG. 1, the FET 1 constituting the first on-off switch SW1 and the FET 2 constituting the second on-off switch SW2 are connected in series between the main battery B1 and the sub-battery B2. .

  The drain electrode of the FET 1 is connected to the source electrode of the FET 2.

  The battery system control apparatus 1A having such a configuration includes the FET1 configuring the first open / close switch SW1, the FET2 configuring the second open / close switch SW2, and the sub battery B2 according to the operation state of the vehicle, etc. The relay 50 can be turned on and off independently by the control of the switching control circuit 10.

  According to the battery system control device 1A, the electric power regenerated by the alternator 11 can be supplied also to the second general load L1b2 by appropriately controlling the opening and closing of the first open / close switch SW1 and the second open / close switch SW2.

  Further, since the dark current of the stabilized load L2 can be supplied from the main battery B1 via the parasitic diodes D1 and D2 of the FET1 and the FET2, it is not necessary to add a switch or a relay separately as in the conventional case. Since the number of parts does not increase, the apparatus can be miniaturized.

(About the current distribution state of the battery system control device according to the first embodiment)
Next, the current distribution state in the battery system control device 1A according to the first embodiment will be described with reference to FIGS.

  In FIGS. 2 to 5, in order to simplify the description, the FET 1 constituting the first on-off switch SW1 and the FET 2 constituting the second on-off switch SW2 are represented by switch symbols.

  The gate drivers G1 and G2 and the switching control circuit 10 are not shown.

(When the ignition switch is off)
FIG. 2 is an explanatory view showing a current distribution state when the ignition switch is off in the battery system control device 1A according to the first embodiment.

  When the ignition switch of the vehicle is off, as shown in FIG. 2, both the FET 1 constituting the first on-off switch SW1 and the FET 2 constituting the second on-off switch SW2 are controlled to be off (cut off). Ru.

  Further, the relay 50 of the sub battery B2 is also controlled to be in the off state.

  As described above, by turning off the relay 50 when the ignition switch is off, the current consumption of the sub-battery B2 can be eliminated.

  On the other hand, the supply of dark current from the main battery B1 to the electric load L is performed via the parasitic diodes D1 and D2 in the forward direction even when the FET1 and the FET2 are not gate-driven. That is, the current I1a from the main battery B1 is supplied to the first general load L1a through the nodes n1 and n3, and the current I1b is supplied to the second general load L1b through the parasitic diode D1 of the FET1 and the node n8. The current I1c is supplied to the stabilized load L2 via the parasitic diodes D1 and D2 of FET1 and FET2 and the node n13.

  At this time, since the dark current (standby current) is reduced to a small current of about several mA to 10 mA, the power loss caused by energizing the parasitic diodes D1 and D2 is also slightly suppressed.

  As described above, the dark current is supplied to all the electric loads L (L1a, L1b, L2) when the ignition switch is off without increasing the number of parts, such as providing a relay separately as in the conventional case. Can.

(When performing a vehicle restart)
FIG. 3 is an explanatory view showing a current distribution state when the vehicle restart is performed in the battery system control device 1A according to the first embodiment.

  For example, when the vehicle is restarted, such as when the engine restarts after the end of idling stop, as shown in FIG. 3, the FET 1 constituting the first open / close switch SW1 is on (energized), the second open / close switch SW2 The FETs 2 constituting the are controlled to be in the off (cut off) state.

  Further, the relay 50 of the sub battery B2 is also controlled to be in the on state.

  In this state, the current I2a from the main battery B1 is supplied to the first general load L1a, the current I2c to the starter motor 12, and the current I2b to the second general load L1b via the first open / close switch SW1. Ru.

  Further, the current I3 from the sub-battery B2 is supplied to the stabilized load L2.

  Thereby, current is supplied from the sub battery B2 to the stabilized load L2 requiring voltage stabilization, and the large current consumption by the starter motor 12 is caused by the off (cut off) state of the FET 2 constituting the second on-off switch SW2. It can be prevented from being affected by the accompanying voltage drop.

(During driving)
FIG. 4 is an explanatory view showing a current distribution state when charging is performed while the vehicle is traveling in the battery system control device 1A according to the first embodiment.

  During traveling of the vehicle, as shown in FIG. 4, both the FET 1 constituting the first open / close switch SW1 and the FET 2 constituting the second open / close switch SW2 are controlled to be in the on (energized) state.

  Further, the relay 50 of the sub battery B2 is controlled to be in the on state.

  Then, the current I4 (I4a to I4f) is supplied to all the electric loads L (L1a, L1b, L2), the main battery B1 and the sub battery B2 by power generation by the alternator 11 during traveling.

  In particular, since the alternator 11 recovers the regenerative energy at the time of deceleration of the vehicle and raises the generated voltage, the charging current I3c and I3f can be supplied to the main battery B1 and the sub battery B2 more.

(When discharging the sub battery while the vehicle is traveling)
FIG. 5 is an explanatory view showing a current distribution state in the case where the sub battery B2 is discharged while the vehicle is traveling in the battery system control device 1A according to the first embodiment.

  For example, when the sub battery B2 is fully charged by the power generated by the alternator 11 by recovery of regenerative energy while the vehicle is traveling, the sub battery is prepared to prepare for the power supply from the alternator 11 by recovery of the next regenerative energy. It is necessary to discharge B2.

  In this case, as shown in FIG. 5, the FET 1 constituting the first open / close switch SW1 is controlled to be off (cut off), and the FET 2 constituting the second open / close switch SW2 is controlled to be on (energized) Be done.

  Further, the relay 50 of the sub battery B2 is controlled to be in the on state.

  Thus, the current I5 (I5a to I5c) from the alternator 11 is supplied to the first general load L1a and the main battery B1.

  On the other hand, the supply of the charging current to the sub-battery B2 is stopped and the FET2 constituting the second on-off switch SW2 is turned on (energized) by the off (cut-off) state of the FET1 forming the first on-off switch SW1. Depending on the state, the currents I6a and I6b of the sub battery B2 are supplied to the second general load L1 b and the stabilized load L2, and discharge from the sub battery B2 is performed.

  At this time, the condition of “main battery voltage ≦ sub battery voltage” may be used as the on / off control condition of the FET 1 and the FET 2 by the switching control circuit 10.

(Configuration Example of Battery System Control Device According to Second Embodiment)
A configuration example of a battery system control device 1B according to the second embodiment will be described with reference to FIG.

  FIG. 6 is a circuit diagram showing an example of a circuit configuration of a battery system control apparatus 1B according to the second embodiment.

  In addition, about the structure similar to the circuit structure of the battery system control apparatus 1A which concerns on 1st Embodiment, the same code | symbol is attached | subjected and the description which overlapped is abbreviate | omitted.

  The difference between the battery system control device 1B according to the second embodiment and the battery system control device 1A according to the first embodiment is that the voltages of the first FET (FET1) and the second FET (FET2) are different. And a voltage detection unit 60 that detects the voltage.

  As shown in FIG. 6, the voltage detection unit 60 is connected to FET1 and FET2 via nodes n30 to n32. Further, the voltage detection unit 60 is connected to input the detected voltage value E1 to the switching control device 10.

  In the battery system control device 1B according to the second embodiment, the switching control device 10 selects the FET 1 and the FET 1 based on the voltage E1 detected by the voltage detection unit 60 (for example, the drain-source voltage of the FET 2). Control is performed to switch on / off of the FET 2 or on / off of the relay 50.

  More specifically, for example, in the above-described state shown in FIG. 3 (when restart is performed), current I2 is supplied from stabilized battery L2 to stabilized load L2. If the battery B2 fails and the voltage drops, the parasitic diode D2 of the FET 2 conducts and a current flows from the main battery (starting battery) B1 to the stabilized load L2.

  For this reason, even if the sub-battery B2 fails, the current supply to the electric loads L (L1a, L1b, L2) is maintained.

  However, the power loss is large when the parasitic diode D2 continues to be energized.

  Therefore, in the battery system control device 1B according to the second embodiment, when the voltage detection unit 60 detects the drain-source voltage of the FET 2 from the voltage of each electric wire and performs off control of the FET 2, a parasitic diode When a voltage corresponding to the on voltage (for example, 0.7 V) of D2 is detected, the switching control circuit 10 controls the FET 2 to turn on.

  Thereby, the current can be supplied from the main battery B1 to the stabilized load L2 in a state where the power loss is reduced.

  Further, in the state shown in FIG. 5 described above (when the sub-battery is discharged while the vehicle is traveling), the current I3b is supplied from the alternator 11 and the main battery B1 to the first general load L1a. When the alternator 11 and the main battery B1 fail due to a reason and the voltage drops, the parasitic diode D1 of the FET 1 conducts (but becomes reverse current) and the sub battery B2 receives the first general load L1a. Current flows to

  Therefore, even in an abnormal situation where the power supply capacity of the main battery B1 is lowered, the current supply to the electric loads L (L1a, L1b, L2) is maintained.

  However, the power loss is large when the current is continued by the parasitic diode D1.

  Therefore, in the battery system control device 1B according to the second embodiment, the voltage detection unit 60 detects the drain-source voltage of the FET 1 from the voltage of each wire, and performs parasitic control in a state in which the FET 1 is turned off. When a voltage corresponding to the on voltage (for example, 0.7 V) of D1 is detected, the switching control circuit 10 controls the FET 1 to turn on.

  Thereby, the current can be supplied from the main battery B2 to the first general load L1a in a state where the power loss is reduced.

  In addition, when the voltage detection unit 60 detects a significant voltage drop of each wire, there is a possibility that an abnormality such as a ground fault has occurred, so an FET (one of FET1 or FET2 or FET1 in an ON state) And FET 2 may be turned off.

  As mentioned above, although the battery system control apparatus of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part is substituted to the thing of the arbitrary structures which have the same function. be able to.

1A, 1B: battery system control device B1: main battery (starting battery)
B2 ... Sub battery (Sub battery for voltage stabilization)
G1: first gate driver G2: second gate driver L: electrical load L1a: first general load L1b: second general load L2: stabilized load 10: switching control circuit (control means)
11 ... Alternator (generator)
12: Starter motor 50: Relay (relay for cut off)
60 voltage detection unit SW1 first switching switch SW2 second switching switch FET1 first FET
FET 2 ... second FET
D1, D2 ... parasitic diode (body diode)

Claims (4)

A generator driven by an output shaft of an engine mounted on a vehicle to generate electric power and generating electric power using regenerative energy;
An electrical load electrically connected in parallel with the generator;
A main battery electrically connected in parallel to the generator and capable of charging generated power of the generator;
A relay electrically connected in parallel with the generator and the main battery, capable of charging the power generated by the generator, having higher output and higher energy density than the main battery and turning on / off a discharge current And a sub-battery
An open / close switch electrically connected to the generator, the electrical load, the main battery, and the sub-battery to switch between conduction and disconnection between the generator, the electrical load, the main battery, and the sub-battery;
Control means for controlling on / off of the relay and opening / closing of the open / close switch;
Equipped with
The electric load includes a first general load and a second general load including a dark current required load that requires supply of dark current from the main battery or the sub battery when the ignition switch of the vehicle is off. Divided into a stabilizing load that receives a stabilized voltage from the battery,
The second general load includes a dark current required load that requires supply of dark current from the main battery or the sub-battery when the ignition switch of the vehicle is off.
The open / close switch is
A first on-off switch for switching between conduction and interruption between the first general load and the second general load;
A second on-off switch for switching between conduction and interruption between the second general load and the stabilization load;
Consists of
and,
A battery system control apparatus, wherein the first open / close switch and the second open / close switch are electrically connected in series between the main battery and the sub-battery. The first open / close switch is connected between a first FET serving as a forward switch with respect to current from the generator or the main battery, and a gate electrode of the first FET and the control means. And the gate driver of the
The second on-off switch is connected between the control means and a second FET serving as a forward switch for current from the generator or the main battery, and a gate electrode of the second FET. And the gate driver of the
The battery system control device according to claim 1, wherein a drain electrode included in the first FET and a source electrode included in the second FET are connected. It further comprises a voltage detection unit that detects the voltage of the first FET and the second FET,
3. The control method according to claim 2, wherein the control means switches on and off of the first FET and the second FET based on the voltage detected by the voltage detection unit. Battery system controller.   The battery system according to any one of claims 1 to 3, wherein a voltage of the sub battery is selected to be equal to or higher than a voltage of the main battery. Control device.

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