JP6922441B2 - Power generation control device - Google Patents

Description

The present invention relates to a power generation control device.

Patent Document 1 describes an alternator control device in which an upper limit of the generated voltage increase rate is set based on a storage battery parameter estimated in advance when increasing the generated voltage of the alternator when charging a mobile storage battery is started. Has been done.

Japanese Unexamined Patent Publication No. 2011-15457

By the way, in the generator control device, when power generation is started when the engine is started, the power generation voltage is set to be lower than the battery voltage so that the generator does not become a load on the engine until the engine is in a complete explosion state and the engine speed stabilizes. It may be controlled to a small value and then controlled to increase the generated voltage so that the battery is charged.

When such control is performed, no current flows through the battery until the generated voltage that starts to rise from a value sufficiently lower than the battery voltage exceeds the battery voltage, so that charging of the battery is delayed.

Further, when charging the battery by the generator, it is desirable not to interfere with the start and operation of the engine.

In the alternator control device described in Patent Document 1 described above, an upper limit is set on the rate of increase in the generated voltage, but consideration is given to quickly starting charging of the battery without interfering with the start and operation of the engine. It has not been.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power generation control device capable of quickly starting charging a battery without interfering with the start and operation of an engine.

The present invention is a power generation control device that controls a generator that is driven by an engine and supplies power to a battery in order to achieve the above object, and includes a power generation voltage control unit that controls the power generation voltage of the generator. When starting power generation by the generator, the power generation voltage control unit raises the power generation voltage at a first rate of change when the power generation voltage is equal to or less than a predetermined rate of change switching voltage threshold, and the power generation voltage is increased. When the change rate switching voltage threshold is larger than the predetermined change rate, the generated voltage is increased by the second change rate smaller than the first change rate, and the predetermined change rate switching voltage threshold is the discharge amount of the battery. and the battery temperature, or, characterized Rukoto is set based on either the temperature of the inter-terminal voltage and the battery of the battery.

According to the present invention, it is possible to provide a power generation control device capable of quickly starting charging of a battery without interfering with the start and operation of the engine.

FIG. 1 is a configuration diagram of a vehicle equipped with a generator controlled by a power generation control device according to an embodiment of the present invention. FIG. 2 is a diagram showing a setting map of a first rate of change switching voltage threshold value referred to in the power generation control device according to the embodiment of the present invention. FIG. 3 is a diagram showing a setting map of a margin voltage referred to in the power generation control device according to the embodiment of the present invention. FIG. 4 is a flowchart showing a processing flow of a power generation instruction voltage rise control in the power generation voltage control executed in the power generation control device according to the embodiment of the present invention. Figure 5 is a flow chart showing the generated voltage control shown in FIG. 4, the flow rate of change determination processing performed in Step S 4 of the power generation instruction voltage increase control. FIG. 6 is a flowchart showing the flow of the change rate switching threshold calculation process executed in step S11 of the change rate determination process shown in FIG. FIG. 7 is a time chart at the time of starting the engine in one embodiment of the present invention. FIG. 8 is a time chart at the time of engine start in the comparative example in which the power generation instruction voltage rise control is not executed in the power generation voltage control in one embodiment of the present invention.

The power generation control device according to the embodiment of the present invention is a power generation control device that controls a generator that is driven by an engine and supplies power to a battery, and includes a power generation voltage control unit that controls the power generation voltage of the generator. When starting power generation by the generator, the power generation voltage control unit raises the power generation voltage at the first rate of change when the power generation voltage is equal to or less than a predetermined rate of change switching voltage threshold, and the power generation voltage changes to a predetermined value. It is characterized in that the generated voltage is increased by a second rate of change smaller than the first rate of change when it is larger than the rate switching voltage threshold. Thereby, the power generation control device according to the embodiment of the present invention can quickly start charging the battery without interfering with the start and operation of the engine.

Hereinafter, a vehicle equipped with a generator controlled by the power generation control device according to the embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the vehicle 1 includes an engine 2 as an internal combustion engine, an ECM (Engine Control Module) 11 for controlling the engine 2, and a BMS (Battery Management System) 15.

A plurality of cylinders are formed in the engine 2. In this embodiment, the engine 2 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder. The rotation output from the engine 2 is changed by a transmission (not shown) and transmitted to the drive wheels.

An ISG (Integrated Starter Generator) 20 and a starter 21 are connected to the engine 2. The ISG 20 is connected to the crankshaft of the engine 2 via a belt 22 or the like. The ISG 20 has a function of an electric motor that rotationally drives the engine 2 by rotating by being supplied with electric power, and a function of a generator that converts the rotational force input from the crankshaft into electric power. The ISG20 in this embodiment constitutes a generator according to the present invention.

In this embodiment, the ISG 20 functions as an electric motor to restart the engine 2 from a stopped state by the idling stop function. The ISG 20 can also assist the traveling of the vehicle 1 by functioning as an electric motor.

The starter 21 includes a motor (not shown) and a pinion gear. The starter 21 rotates the crankshaft by rotating the motor to give the engine 2 a rotational force at the time of starting. In this way, the engine 2 is started by the starter 21 and restarted by the ISG 20 from the stopped state by the idling stop function.

The vehicle 1 includes a first power storage device 30 as a battery, a second power storage device 31, and a cable 36. The first power storage device 30 and the second power storage device 31 are composed of a rechargeable secondary battery. The first power storage device 30 is made of a lead battery.

The second power storage device 31 is a power storage device having a higher output and a higher energy density than the first power storage device 30. The second power storage device 31 can be charged in a shorter time than the first power storage device 30. In this embodiment, the second power storage device 31 is made of a lithium ion battery. The second power storage device 31 may be a nickel-metal hydride storage battery.

The first power storage device 30 and the second power storage device 31 are batteries in which the number of cells and the like are set so as to generate an output voltage of about 12 V.

The vehicle 1 is provided with a general load 37 as an electric load and a protected load 38. The general load 37 and the protected load 38 are electrical loads other than the starter 21 and the ISG 20.

The protected load 38 is an electric load that is always required to have a stable power supply. The protected load 38 includes a stability control device that prevents the vehicle 1 from skidding, an electric power steering control device that electrically assists the operating force of the steering wheels, and a headlight. The protected load 38 also includes lamps and meters of an instrument panel (not shown) and a car navigation system.

The general load 37 is an electric load that is temporarily used without requiring a stable power supply as compared with the protected load 38. The general load 37 includes, for example, a wiper (not shown) and an electric cooling fan that blows cooling air to the engine 2.

The first power storage device 30 and the second power storage device 31 are connected via a cable 36 so as to be able to supply electric power to the starter 21, the ISG 20, the general load 37 as an electric load, and the protected load 38. The first power storage device 30 and the second power storage device 31 are electrically connected in parallel to the protected load 38.

A switch 40 is provided on the cable 36 between the second power storage device 31 and the protected load 38. A switch 41 is provided on the cable 36 between the first power storage device 30 and the protected load 38.

The BMS 15 has a function of receiving an instruction signal from the ECM 11 described later, and in principle controls opening and closing of the switches 40 and 41 according to the received instruction signal. However, for the purpose of protecting the second power storage device 31 and stable operation of the protected load 38, an operation different from the instruction signal from the ECM 11 may be performed.

The BMS 15 controls the opening and closing of the switches 40 and 41 to control the charging / discharging of the second power storage device 31 and the power supply to the protected load 38. When the engine 2 is stopped due to idling stop, the BMS 15 closes the switch 40 and opens the switch 41 to supply electric power to the protected load 38 from the second power storage device 31 having high output and high energy density. It has become like.

The BMS 15 is a first power storage device by closing the switch 40 and opening the switch 41 when the engine 2 is started by the starter 21 and when the engine 2 stopped by the idling stop control is restarted by the ISG 20. Power is supplied from 30 to the starter 21 or the ISG 20. When the switch 40 is closed and the switch 41 is opened, electric power is also supplied from the first power storage device 30 to the general load 37.

As described above, the first power storage device 30 is adapted to supply at least electric power to the starter 21 and the ISG 20 as starting devices for starting the engine 2. The second power storage device 31 is adapted to supply at least power to the general load 37 and the protected load 38.

The second power storage device 31 is connected so as to be able to supply power to both the general load 37 and the protected load 38, but preferentially supplies power to the protected load 38, which is always required to have a stable power supply. The switches 40 and 41 are controlled by the BMS 15.

In the BMS 15, the protected load 38 operates stably in consideration of the charging state (remaining charge) of the first power storage device 30 and the second power storage device 31 and the operation request to the general load 37 and the protected load 38. The switches 40 and 41 may be controlled differently from the above-described example in order to give priority to the above.

The ECM 11 and BMS 15 have a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, an input port, and an output port, respectively. It is composed of a built-in computer unit.

The ROM of these computer units stores various constants, various maps, and the like, as well as programs for making the computer unit function as ECM11 and BMS15, respectively.

That is, when the CPU executes the program stored in the ROM using the RAM as the work area, these computer units function as the ECM 11 and the BMS 15 in this embodiment, respectively.

In this embodiment, the ECM 11 is designed to execute idling stop control. In this idling stop control, the ECM 11 stops the engine 2 when a predetermined stop condition is satisfied, and drives the ISG 20 to restart the engine 2 when the predetermined restart condition is satisfied. Therefore, unnecessary idling of the engine 2 is not performed, and the fuel efficiency of the vehicle 1 can be improved.

The vehicle 1 is provided with a CAN communication line 49 for forming an in-vehicle LAN (Local Area Network) conforming to a standard such as CAN (Controller Area Network). The ECM 11 and the BMS 15 are connected to the CAN communication line 49 and mutually transmit and receive signals such as control signals via the CAN communication line 49.

A battery sensor 32 including a current sensor, a voltage sensor, a battery temperature sensor, and the like is connected to the ECM 11. The ECM 11 uses the output of the battery sensor 32 to charge / discharge the first power storage device 30 (hereinafter referred to as “Pb battery current”), the terminal voltage of the first power storage device 30 (hereinafter referred to as “Pb battery voltage”), and the first power storage device. The temperature of the device 30 (hereinafter referred to as "battery temperature") can be detected.

The ECM 11 has a function as a DOD calculation unit 11A for calculating a discharge depth (hereinafter referred to as “DOD (Depth of Discharge)”) [%] representing the ratio of the discharge amount to the discharge capacity of the first power storage device 30. The ECM 11 calculates the DOD based on the integrated value of the discharge current of the first power storage device 30 during discharge and the discharge capacity of the first power storage device 30. Specifically, the ECM 11 calculates the DOD based on the calculation formula "DOD [%] = 100-SOC (State of Charge) [%] of the first power storage device 30".

The ECM 11 has a function as a power generation voltage control unit 11B that controls the power generation voltage of the ISG 20 via a controller for controlling the ISG 20 (not shown). The ECM 11 is adapted to raise the power generation voltage at a plurality of different rates of change when starting power generation by the ISG 20 by executing the power generation instruction voltage rise control described later. The power generation voltage in this embodiment means the power generation instruction voltage indicated by the ECM 11 to the ISG 20.

In this embodiment, the rate of change ΔV of the power generation instruction voltage when the power generation instruction voltage is increased is smaller than the first rate of change ΔV1 in which the degree of increase in the power generation instruction voltage is steep and the first rate of change ΔV1. That is, the second rate of change ΔV2, in which the degree of increase in the power generation instruction voltage is slower than that of the first rate of change ΔV1, is used.

The first rate of change ΔV1 and the second rate of change ΔV2 may be fixed values experimentally obtained in advance and stored in the ROM of the ECM 11, the state of the first power storage device 30, the engine rotation speed, and the like. It may be a value that fluctuates according to.

The first change rate ΔV1 and the second change rate ΔV2 indicate whether the power generation instruction voltage is equal to or less than the predetermined change rate switching voltage threshold value Va when the power generation instruction voltage is raised, or the predetermined change rate switching voltage threshold value Va. It can be switched depending on whether it is larger than.

When the ECM 11 starts power generation by the ISG 20, if the power generation instruction voltage is equal to or less than the predetermined change rate switching voltage threshold value Va, the ECM 11 sets the first change rate ΔV1 as the change rate ΔV of the power generation instruction voltage. When the ECM 11 starts power generation by the ISG 20, if the power generation instruction voltage is larger than the predetermined change rate switching voltage threshold value Va, the ECM 11 sets the second change rate ΔV2 as the change rate ΔV of the power generation instruction voltage.

As a result, when the ECM 11 starts power generation by the ISG 20, when the power generation instruction voltage is equal to or less than the predetermined change rate switching voltage threshold value Va, the ECM 11 raises the power generation instruction voltage at the first change rate ΔV1 and the power generation instruction voltage becomes When the change rate switching voltage threshold value Va is larger than the predetermined change rate switching voltage threshold value Va, the power generation instruction voltage can be increased by the second change rate ΔV2.

The ECM 11 calculates the first rate of change switching voltage threshold value V1 with reference to the setting map shown in FIG. 2 based on the DOD of the first power storage device 30 and the battery temperature. In the setting map shown in FIG. 2, the larger the DOD and the lower the battery temperature, the smaller the value of the first change rate switching voltage threshold value V1, and the smaller the DOD and the higher the battery temperature, the smaller the first change rate. It is specified that the value of the switching voltage threshold value V1 becomes large.

The ECM 11 calculates the second rate of change switching voltage threshold value V2 based on the Pb battery voltage and the battery temperature. Specifically, the ECM 11 calculates the margin voltage Vmg based on the battery temperature of the first power storage device 30 with reference to the setting map of FIG. In the setting map of FIG. 3, it is specified that the value of the margin voltage Vmg becomes smaller as the battery temperature is higher.

The ECM 11 calculates the value obtained by subtracting the margin voltage Vmg from the Pb battery voltage as the second rate of change switching voltage threshold value V2. Therefore, the second rate of change switching voltage threshold value V2 is calculated as a larger value as the battery temperature is higher.

The ECM 11 now sets the smaller value of the first change rate switching voltage threshold value V1 and the second change rate switching voltage threshold value V2 calculated as described above as the predetermined change rate switching voltage threshold value Va. ing. When the first change rate switching voltage threshold value V1 and the second change rate switching voltage threshold value V2 are the same, the ECM 11 sets the first change rate switching voltage threshold value V1 as a predetermined change rate switching voltage threshold value Va. ..

Next, with reference to FIGS. 4 to 6, the power generation instruction voltage rise control in the power generation voltage control executed by the power generation control device according to the present embodiment will be described. The generated voltage control is repeatedly executed by the ECM 11 at predetermined time intervals. When the power generation voltage control is started, the power generation voltage is controlled to a predetermined value to the extent that the first power storage device 30 is charged, but the power generation voltage at this time rises until it reaches a predetermined value. The method of making the power generation is controlled by the power generation instruction voltage rise control shown in FIG. That is, the power generation instruction voltage rise control is executed by the ECM 11, and indicates a part of the power generation voltage control.

As shown in FIG. 4, the ECM 11 determines whether or not the engine has just started (step S1). Specifically, the ECM 11 determines whether or not the time after the engine start is completed (hereinafter, referred to as "post-start time") is within a predetermined time. The ECM 11 determines that the engine has just started when the time after the start is within a predetermined time. The ECM 11 determines that the engine start is completed when the actual engine rotation speed reaches the complete explosion determination engine rotation speed at which the engine 2 can operate independently, that is, when the engine complete explosion determination is established.

If it is determined in step S1 that the ECM 11 is not immediately after the engine is started, the ECM 11 ends the power generation instruction voltage rise control. When the ECM 11 determines in step S1 that the engine has just started, the ECM 11 maintains the power generation instruction voltage at a predetermined value (step S2). The “predetermined value” in this step is the minimum value of the power generation instruction voltage, for example, about 10.6V. The predetermined value is not limited to the minimum value of the power generation instruction voltage.

Next, the ECM 11 determines whether or not a predetermined time has elapsed after the engine start is completed (step S3). If the ECM 11 determines that the predetermined time has not elapsed after the engine start is completed, the process returns to step S2.

When the ECM 11 determines that a predetermined time has elapsed after the engine start is completed, the ECM 11 shifts the process to step S4. As a result, the power generation instruction voltage is maintained at a predetermined value for a predetermined time after the engine start is completed.

The "predetermined time" in step S3 corresponds to the time from the completion of engine start to the stabilization of the engine rotation speed, and is set to, for example, about 2 seconds in this embodiment. As a result, the power generation load generated by the ISG 20 does not hinder the stabilization of the engine rotation speed immediately after the completion of engine start. The predetermined time varies depending on the specifications of the vehicle and engine, and is not limited to 2 seconds.

In step S4, the ECM 11 executes the rate of change determination process shown in FIG. In this step, the rate of change ΔV of the power generation instruction voltage when the power generation instruction voltage is gradually increased in step S5 described later is determined.

Next, the ECM 11 gradually raises the power generation instruction voltage with respect to the ISG 20 at the change rate ΔV of the power generation instruction voltage determined by the change rate determination process in step S4 (step S5).

After that, the ECM 11 determines whether or not the Pb battery voltage has reached a desired Pb battery voltage (step S6). The desired Pb battery voltage is a voltage at which the first power storage device 30 can be continuously charged, and is a value higher than the Pb battery voltage at the time of full charge. In this embodiment, it is, for example, about 14V to 15V.

If the ECM 11 determines that the Pb battery voltage has not reached the desired Pb battery voltage, the process returns to step S4. When the ECM 11 determines that the Pb battery voltage has reached a desired Pb battery voltage, the ECM 11 ends the power generation instruction voltage rise control.

Next, the rate of change determination process shown in FIG. 5 will be described. As described above, the rate of change determination process is a process executed in step S4 of the power generation instruction voltage rise control shown in FIG.

As shown in FIG. 5, the ECM 11 executes the change rate switching threshold calculation process shown in FIG. 6 in step S11. In this step, the rate of change switching voltage threshold value Va used in the determination in step S12, which will be described later, is calculated.

Next, the ECM 11 determines whether or not the power generation instruction voltage is equal to or less than or equal to the change rate switching voltage threshold value Va calculated in the change rate switching threshold value calculation process in step S11 (step S12).

When the ECM 11 determines that the power generation instruction voltage is equal to or less than the change rate switching voltage threshold value Va, the ECM 11 determines the first change rate ΔV1 as the change rate ΔV of the power generation instruction voltage (step S13), and performs the change rate determination process. finish.

When the ECM 11 determines that the power generation instruction voltage is not equal to or less than the change rate switching voltage threshold value Va, the ECM 11 determines the second change rate ΔV2 as the change rate ΔV of the power generation instruction voltage (step S14), and ends the change rate determination process. do.

Next, the rate of change switching threshold calculation process shown in FIG. 6 will be described. As described above, the change rate switching threshold calculation process is a process executed in step S11 of the change rate determination process shown in FIG.

As shown in FIG. 6, in step S21, the ECM 11 calculates the first rate of change switching voltage threshold value V1 with reference to the setting map shown in FIG. 2 based on the DOD of the first power storage device 30 and the battery temperature. ..

Next, the ECM 11 calculates the second rate of change switching voltage threshold value V2 based on the Pb battery voltage and the battery temperature (step S22). Specifically, the ECM 11 calculates a value obtained by subtracting the margin voltage Vmg from the Pb battery voltage as the second rate of change switching voltage threshold value V2.

Next, the ECM 11 determines whether or not the first change rate switching voltage threshold value V1 is equal to or less than the second change rate switching voltage threshold value V2 (step S23).

When the ECM 11 determines that the first change rate switching voltage threshold value V1 is equal to or less than the second change rate switching voltage threshold value V2, the ECM 11 sets the first change rate switching voltage threshold value V1 to a predetermined change rate switching voltage threshold value Va. (Step S24), and the change rate switching threshold calculation process is completed.

When the ECM 11 determines that the first change rate switching voltage threshold value V1 is not equal to or less than the second change rate switching voltage threshold value V2, the second change rate switching voltage threshold value V2 is set as a predetermined change rate switching voltage threshold value Va. After setting (step S25), the change rate switching threshold calculation process is completed.

Here, the predetermined rate of change switching voltage threshold value Va described above is equal to or less than the Pb battery voltage. When the power generation instruction voltage of the ISG 20 exceeds the Pb battery voltage, charging of the first power storage device 30 is started. At this time, the drive of the ISG 20 becomes the load of the engine 2. Therefore, when charging the first power storage device 30 is started, it is preferable to raise the power generation instruction voltage at a small rate of change so that the engine 2 is not suddenly loaded.

In this embodiment, power is generated at a small rate of change when the first power storage device 30 is started so that the engine 2 is not suddenly loaded when the first power storage device 30 is started to be charged. Increase the indicated voltage. On the other hand, until the charging of the first power storage device 30 is started, the power generation instruction voltage is increased at a large rate of change so that the charging of the first power storage device 30 is started promptly.

Therefore, the timing for switching from the state in which the power generation instruction voltage is increased at a large rate of change to the state in which the power generation instruction voltage is increased at a small rate of change is at least before the charging of the first power storage device 30 is started. preferable. Therefore, in this embodiment, a predetermined change rate switching voltage threshold value Va, which serves as a reference for switching the change rate ΔV of the power generation instruction voltage from the first change rate ΔV1 to the second change rate ΔV2, is set to be equal to or lower than the Pb battery voltage. NS.

Next, with reference to FIGS. 7 and 8, the time chart at the time of starting the engine of this embodiment will be described in comparison with the comparative example in which the power generation instruction voltage rise control is not executed. 7 and 8 are both time charts when the engine is restarted by ISG.

As shown in FIG. 7, in this embodiment, when the engine complete explosion determination is established at time t1 and the engine start is completed, the power generation instruction voltage is maintained at, for example, the minimum value for the predetermined time P1 until time t2. Will be done. The predetermined time P1 corresponds to the time from the completion of the engine start to the stabilization of the engine rotation speed.

After that, in this embodiment, the power generation instruction voltage starts to rise from time t2. The rate of change of the power generation instruction voltage at this time is the first rate of change ΔV1 in which the degree of increase is steep.

After that, when the power generation instruction voltage that rises at the first change rate ΔV1 exceeds the change rate switching voltage threshold value Va at time t3, the change rate of the power generation instruction voltage changes from the first change rate ΔV1 to the first change rate ΔV1. It is switched to the second rate of change ΔV2 in which the degree of increase is gradual. As a result, the power generation instruction voltage rises at the second rate of change ΔV2 from the time t3.

After that, the power generation instruction voltage exceeds the Pb battery voltage at time t4. When the power generation instruction voltage exceeds the Pb battery voltage at time t4, a charging current flows through the first power storage device 30 as a Pb battery current, and charging of the first power storage device 30 is started. As a result, the Pb battery voltage starts to rise from time t4.

Until time t4, since the power generation instruction voltage does not exceed the Pb battery voltage, the ECM 11 does not output the power generation instruction to the ISG 20. Therefore, no ISG power generation torque is generated until time t4.

After that, at time t5, the Pb battery voltage reaches the desired Pb battery voltage, and the power generation instruction voltage rise control ends. That is, the rise in the generated voltage ends and is controlled to reach a constant value. After the power generation instruction voltage rise control is completed, charging is continued according to the remaining capacity of the first power storage device 30. The generated voltage when charging is continued is controlled to the desired Pb battery voltage described above.

On the other hand, as shown in FIG. 8, in the comparative example, the power generation instruction voltage starts to rise from the time t12 after the lapse of the predetermined time P1 after the engine start is completed, but the rate of change of the power generation instruction voltage at this time is The rate of change is gradual as compared with this example.

Therefore, in the comparative example, it takes a relatively long time from the start of the rise of the power generation instruction voltage until the power generation instruction voltage exceeds the Pb battery voltage. That is, in the comparative example, the time P3 from the time t12 to the time t13 is relatively long.

On the other hand, in this embodiment, as shown in FIG. 7, the power generation instruction voltage is first increased at the first rate of change ΔV1 where the degree of increase is steep, and then the second rate of change ΔV2 where the degree of increase is gradual. Raises the power generation instruction voltage with. Therefore, in this embodiment, as compared with the comparative example, the time P2 from the start of the increase in the power generation instruction voltage to the time when the power generation instruction voltage exceeds the Pb battery voltage is significantly shortened.

As described above, when the power generation control device according to the present embodiment starts power generation by the ISG20, the power generation instruction is given at the first change rate ΔV1 having a large change rate until the power generation instruction voltage reaches the change rate switching voltage threshold value Va. Increase the voltage.

Therefore, the power generation control device according to the present embodiment can shorten the time P2 (see FIG. 7) until the power generation instruction voltage exceeds the Pb battery voltage, and promptly starts charging the first power storage device 30. can do. If charging of the first power storage device 30 can be started promptly, for example, a long charging time can be secured and the charge amount of the first power storage device 30 can be increased.

Further, in the power generation control device according to the present embodiment, when the power generation by the ISG 20 is started, after the power generation instruction voltage exceeds the change rate switching voltage threshold value Va, the second change rate ΔV2 is smaller than the first change rate ΔV1. Raises the power generation instruction voltage with.

Therefore, the power generation control device according to the present embodiment can moderate the degree of increase in the power generation instruction voltage when charging the first power storage device 30 is started. As a result, the power generation control device according to the present embodiment can prevent the engine 2 from being suddenly loaded when charging the first power storage device 30 is started. Therefore, the power generation control device according to the present embodiment can prevent the start and operation of the engine 2 from being hindered by the start of power generation by the ISG 20.

Further, in the power generation control device according to the present embodiment, the smaller value of the first change rate switching voltage threshold value V1 and the second change rate switching voltage threshold value V2 is set as the change rate switching voltage threshold value Va. Therefore, in the power generation control device according to the present embodiment, even if an error occurs in the calculation of the DOD or the Pb battery voltage is erroneously detected, the rate of change switching voltage threshold value Va exceeding the Pb battery voltage is set. It can be prevented from being set.

In the power generation control device according to the present embodiment, as shown in FIG. 4, an example in which the power generation instruction voltage increase control is executed immediately after the engine is started has been described, but the situation is such that the power generation instruction voltage for the ISG 20 is increased. If so, the power generation instruction voltage rise control may be executed not only immediately after the engine is started.

Although the embodiments of the present invention have been disclosed, it is clear that some skilled in the art can make changes without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

1 vehicle 2 engine 11 ECM
11A DOD calculation unit 11B Power generation voltage control unit 15 BMS
20 ISG (generator)
30 First power storage device (battery)
31 Second power storage device 32 Battery sensor ΔV Change rate ΔV1 First change rate ΔV2 Second change rate Va Change rate switching voltage threshold V1 First change rate switching voltage threshold V2 Second change rate switching voltage threshold Vmg Margin voltage

Claims (3)

A power generation control device that controls a generator that is driven by an engine and supplies power to a battery.
A power generation voltage control unit for controlling the power generation voltage of the generator is provided.
The generated voltage control unit
When starting power generation by the generator, when the generated voltage is equal to or less than a predetermined rate of change switching voltage threshold value, the generated voltage is increased by the first rate of change.
When the generated voltage is larger than the predetermined rate of change switching voltage threshold value, the generated voltage is increased by a second rate of change smaller than the first rate of change .
It said predetermined rate switching voltage threshold, the battery discharge amount and the battery temperature, or power control, characterized in Rukoto is set based on either the temperature of the terminal voltage of the battery battery Device. The power generation control device according to claim 1, wherein the predetermined rate of change switching voltage threshold value is equal to or lower than the voltage between terminals of the battery. The generated voltage control unit calculates the first rate of change switching voltage threshold based on the discharge amount of the battery and the temperature of the battery, and the second is based on the voltage between the terminals of the battery and the temperature of the battery. The change rate switching voltage threshold of the above is calculated, and the smaller value of the first change rate switching voltage threshold and the second change rate switching voltage threshold is set as the predetermined change rate switching voltage threshold. The power generation control device according to claim 1 or 2.

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