JP2016132324A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately supply electric power to a load after an engine is restarted in relation to a vehicle which is provided with a lead-acid battery and a nickel-hydrogen battery and in which a relay provided between a generator and the lead-acid battery, and the nickel-hydrogen battery is turned off when the engine is stopped by idling-stop.SOLUTION: A power supply device (100) comprises control means (21) for turning on a relay (22) so as to carry a current between power generation means (12) and a lead-acid battery (15), and a nickel-hydrogen battery (17) on condition that an SOC of the lead-acid battery has returned to a predetermined capacity on the basis of an integrated value of a charge/discharge current or the SOC of the lead-acid battery or that predetermined time has elapsed since restart of an engine (31) after automatic stop thereof.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power supply device for a vehicle such as an automobile, and more particularly to the technical field of a power supply device for a vehicle having an idling stop mechanism.

  As this type of device, for example, a device comprising a lead storage battery, a lithium ion battery, and a connection switch for energizing and shutting off both the batteries, and when the engine is idling stopped, the connection switch is turned off. An apparatus has been proposed that turns on the connection switch when regenerative power generation is performed after restart (see Patent Document 1).

JP 2014-034288 A

  In the technique described in Patent Document 1, if regenerative power generation is not performed for a relatively long time after the engine is restarted, for example, when the power consumption of the load increases rapidly, there is a possibility that power is not appropriately supplied to the load. There is a technical problem.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide a power supply device capable of appropriately supplying power to the load even when the power consumption of the load suddenly changes.

  In order to solve the above-described problem, a power supply device of the present invention is mounted on a vehicle including an engine having an idling stop function, and a first battery and a second battery that are electrically connected to the power generation means and the power generation means, respectively. And a switch capable of switching between energization and shutoff of the power generation means and the first battery and the second battery, wherein the charge / discharge current of each of the first battery and the second battery is A battery state calculation means for calculating an integrated value or SOC (State of Charge), and when the engine is automatically stopped by the idling stop function, the power generation means and the first battery and the second battery Control means for controlling the switch to shut off, the control means calculating the battery state Based on the integrated value or SOC of the charge / discharge current of the first battery calculated by the means, the SOC of the first battery has recovered to a predetermined amount, or a predetermined time after the engine is restarted after automatic stop The switch is controlled so that the power generation means and the first battery and the second battery are energized on the condition that the time has elapsed.

  According to the power supply device of the present invention, the power supply device is mounted on a vehicle including an engine having an idling stop function. The power supply apparatus includes a power generation unit, a first battery, a second battery, a switch, a battery state calculation unit, and a control unit.

  For example, the switch is disposed between the power generation means, the first battery, and the second battery, thereby switching between energization and interruption of the power generation means, the first battery, and the second battery.

  For example, a battery state calculation unit including a memory, a processor, and the like calculates an integrated value or SOC of charge / discharge currents of the first battery and the second battery. Here, “calculating the integrated value of charge / discharge current or SOC” means “calculating at least one of the integrated value of charge / discharge current and SOC”. In addition to the integrated value, the SOC and other physical quantities or parameters may be calculated. In addition, since various well-known aspects are applicable to calculation of the integrated value of charging / discharging current and SOC, the description about the detail is omitted.

  For example, the control means including a memory, a processor, and the like controls the switch so that the power generation means and the first battery and the second battery are disconnected when the engine is automatically stopped by the idling stop function (that is, , Switch off).

  Particularly in the present invention, the control means recovers the SOC of the first battery to a predetermined amount based on the integrated value or SOC of the charge / discharge current of the first battery calculated by the battery state calculation means, or the engine The switch is controlled to energize between the power generation means and the first battery and the second battery on the condition that a predetermined time has passed since restarting after the automatic stop (that is, the switch is turned on). .

  Here, according to the inventor's research, the following matters have been found. That is, when the engine is automatically stopped by the idling stop function, the switch is turned off to disconnect the second battery from the power generation means, and immediately after the engine is restarted, the switch is turned on to electrically connect the second battery and the power generation means. It is possible to improve fuel efficiency by connecting to the power source and supplying power from both the first battery and the second battery, or by collecting regenerative power at both the first battery and the second battery.

  On the other hand, depending on the running state, the SOC of the first battery may decrease, and a situation where idling stop cannot be performed may occur. Then, the frequency of idling stops decreases, and as a result, fuel consumption may deteriorate. However, for example, as in the technique described in Patent Document 1, if the switch is in an off state until regenerative power generation is performed after the engine is restarted, if the power consumption of the load suddenly increases when the switch is off, There is a possibility that power is not properly supplied to the load, and the operation of the load becomes unstable.

  Therefore, in the present invention, as described above, on the condition that the SOC of the first battery has been recovered to a predetermined amount by the control means, or that a predetermined time has elapsed since the engine was restarted after automatic stop, The switch is controlled so as to energize between the first battery and the second battery.

  If comprised in this way, since a 1st battery is charged preferentially after engine restart, the fall of the frequency of idling stop can be suppressed. In addition, when the SOC of the first battery recovers to a predetermined amount or when a predetermined time elapses after the engine is restarted, the power generation means and the first battery and the second battery are energized, thereby improving fuel efficiency. In addition, it is possible to appropriately cope with a sudden change in the power consumption of the load.

  The “predetermined amount” may be set to, for example, the lower limit value of the SOC necessary for performing the idling stop. The “predetermined time” is a period of time when the possibility that the power consumption of the load changes suddenly after engine restart is relatively low or hardly after experimentally or empirically or by simulation. May be set as a period shorter by a predetermined value.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a schematic block diagram which shows the structure of the power supply device which concerns on embodiment. It is a flowchart which shows the parallel relay control process which concerns on embodiment.

  An embodiment according to a power supply device of the present invention will be described with reference to the drawings.

(Constitution)
The configuration of the power supply device according to the embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram illustrating a configuration of a power supply device according to the embodiment.

  In FIG. 1, the power supply device 100 is mounted on a vehicle (not shown) including an engine 31. The power supply device 100 includes an alternator 12, a lead battery 15, a nickel metal hydride battery 17, and an ECU (Electronic Control Unit) 21.

  The alternator 12 is configured to be able to generate power using the driving force of the engine 31. The ECU 21 is built in a battery unit including the nickel metal hydride battery 17. The ECU 21 is electrically connected (not shown) so that not only the electric power from the nickel metal hydride battery 17 but also the electric power generated by the alternator 12 and the electric power from the lead battery 15 are supplied.

  The ECU 21 is configured to be able to calculate the integrated value of the charging current and the integrated value of the discharging current of each of the lead battery 15 and the nickel metal hydride battery 17. The ECU 21 is further configured to be able to calculate the SOC of each of the lead battery 15 and the nickel metal hydride battery 17. It should be noted that various known modes can be applied to the method for obtaining the integrated value of the charging current and the integrated amount of the discharge current, and the method for obtaining the SOC, and therefore, detailed description thereof is omitted.

  As shown in FIG. 1, a parallel relay 22 and a protection relay 23 are disposed between the lead battery 15 and the nickel metal hydride battery 17. Each of the parallel relay 22 and the protection relay 23 is controlled by the ECU 21. In the following description, ON / OFF of the protection relay 23 is not mentioned, but in the present embodiment, the protection relay 23 is always on.

  The power supply device 100 is electrically connected to a starter motor 11, a load 13, an electric active stabilizer 14, a redundant power load 16, and an ECU 32 that are provided in the vehicle. The ECU 32 is configured to be able to communicate with the ECU 21. The load 13 includes, for example, a water pump, a wiper, and a light. The redundant power load 16 includes devices that require power backup such as shift-by-wire.

  The ECU 32 automatically stops the engine 31 when the vehicle is stopped. For example, the ECU 32 restarts the engine 31 when the driver stops the brake pedal or when the accelerator pedal is depressed. Control processing (so-called idling stop) can be performed. In addition, about an idling stop technique, well-known various aspects are applicable.

  The “alternator 12”, “lead battery 15”, “nickel metal hydride battery 17” and “parallel relay 22” according to the present embodiment are respectively referred to as “power generation means”, “first battery”, “second battery” according to the present invention. It is an example of a “battery” and a “switch”.

(Parallel relay control processing)
A parallel relay control process performed by the ECU 21 in the power supply device 100 configured as described above will be described with reference to a flowchart of FIG.

  In FIG. 2, the ECU 21 communicates with the ECU 32 to determine whether or not the engine 31 is being automatically stopped (step S <b> 101). When it is determined that the engine 31 is automatically stopped (step S101: Yes), the ECU 21 turns off the parallel relay 22 (step S102).

  Subsequently, the ECU 21 detects the discharge current of the lead battery 15 and updates the integrated amount A of the discharge current of the lead battery 15 (step S103).

  When the engine 31 is automatically stopped, the ECU 21 periodically performs the processes of steps S101 to S103 described above.

  If it is determined in step S101 that the engine 31 is not being automatically stopped (step S101: No), the ECU 21 detects the charging current of the lead battery 15 and calculates the accumulated amount B of the charging current of the lead battery 15. Update (step S104).

  Next, the ECU 21 determines whether or not the SOC of the lead battery 15 has recovered a certain amount after the engine 31 is restarted, and whether or not a certain time (for example, 30 seconds) has elapsed after the engine 31 is restarted. Determination is made (step S105).

  Specifically, for example, the ECU 21 determines whether or not the integrated amount B of the charge current of the lead battery 15 is equal to or more than the product of the integrated amount A of the discharge current of the lead battery 15 and the coefficient α. It is determined whether or not the SOC of the lead battery 15 has recovered a certain amount. The coefficient α is a variable value that changes according to the charge / discharge tendency of the vehicle.

  Alternatively, the ECU 21 determines whether or not the SOC of the lead battery 15 has recovered a certain amount by determining whether or not the integrated amount B of the charging current of the lead battery 15 is equal to or greater than a fixed value such as 150 [As]. Determine whether. Note that, in the configuration in which the accumulated amount B of the charging current is compared with the fixed value, the process of step S103 described above may not be performed.

  Alternatively, the ECU 21 obtains the SOC of the lead battery 15 from the accumulated amount A of the discharge current and the accumulated amount B of the charging current of the lead battery 15, for example, and whether or not the obtained SOC is a predetermined value or more. It is determined whether or not the SOC of the lead battery 15 has recovered by a certain amount.

  If it is determined that the SOC of the lead battery 15 has recovered a certain amount or a certain time has elapsed after the engine 31 is restarted (step S105: Yes), the ECU 21 turns on the parallel relay 22 (step S106).

  On the other hand, when it is determined that the SOC of the lead battery 15 has not recovered a certain amount and the certain time has not elapsed after the engine 31 is restarted (step S105: No), the ECU 21 once performs the process. finish.

  If comprised in this way, since the lead battery 15 is charged preferentially after the restart of the engine 31, the fall of the frequency of idling stop can be suppressed. In addition, since the parallel relay 22 is turned on when the SOC of the lead battery 15 recovers a certain amount or when a certain time elapses after the engine 31 is restarted, the regenerative power is recovered by the lead battery 15 and the nickel metal hydride battery 17. This can improve fuel efficiency.

  Further, even if the power consumption of the load 13 and the electric active stabilizer 14 changes suddenly after the engine 31 is restarted (that is, during traveling of the vehicle), power is supplied from both the lead battery 15 and the nickel metal hydride battery 17. The load 13 and the electric active stabilizer 14 can be stably operated.

  The “ECU 21” according to the embodiment is an example of the “battery state calculation unit” and the “control unit” according to the present invention.

  In place of the nickel metal hydride battery 17, for example, a lithium ion battery or the like may be used.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Moreover, it is included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Starter motor, 12 ... Alternator, 13 ... Load, 14 ... Electric active stabilizer, 15 ... Lead battery, 16 ... Redundant power supply load, 17 ... Nickel metal hydride battery, 21, 32 ... ECU, 22 ... Parallel relay, 23 ... Protection Relay, 31 ... engine, 100 ... power supply

Claims (1)

Mounted in a vehicle including an engine having an idling stop function, the power generation means, a first battery and a second battery electrically connected to the power generation means, respectively, the power generation means, the first battery, and the second battery A switch that can be switched between energization and interruption with
Battery state calculation means for calculating an integrated value or SOC of charge / discharge current of each of the first battery and the second battery;
Control means for controlling the switch so as to cut off the power generation means and the first battery and the second battery when the engine is automatically stopped by the idling stop function;
With
The control means recovers the SOC of the first battery to a predetermined amount based on the integrated value or SOC of the charge / discharge current of the first battery calculated by the battery state calculation means, or the engine automatically The switch is controlled to energize between the power generation means and the first battery and the second battery on condition that a predetermined time has elapsed since restarting after stopping. .

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