JP2010178531A - Power generation controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power generation controller for a vehicle having a simple configuration by which the output of an alternator can be adequately controlled. <P>SOLUTION: The power generation controller for the vehicle includes: the alternator which is mounted on the vehicle and supplies electric power to on-vehicle equipment including a battery; a vehicle state acquisition means which acquires a vehicle state including the speed of the vehicle; an adjustment voltage determination means by which an adjustment voltage of the alternator is determined using references, which are different at high output and low output of the alternator, determined based on the vehicle state acquired by the vehicle state acquisition means. During the low output of the alternator, with a tendency that the adjustment voltage of the alternator becomes lower as an integrated value of the difference between the adjustment voltage and a predetermined voltage of the alternator with a predetermined point in time as a reference becomes large, and the adjustment voltage of the alternator becomes higher as the integrated value of the difference becomes small, the adjustment voltage determination means determines the adjustment voltage of the alternator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicular power generation apparatus that adjusts an output of an alternator that generates electric power according to an output of an engine based on a vehicle state such as a vehicle speed.

  2. Description of the Related Art Conventionally, a vehicle is equipped with an alternator that generates electric power by the output of an engine, and power is supplied to a battery and other in-vehicle devices by the alternator. This alternator is generally configured such that the generated voltage can be changed by changing an adjustment voltage set in an internal IC regulator or the like.

  The alternator adjustment voltage is controlled by setting the adjustment voltage low when the vehicle is stopped, accelerating, running at a constant speed, etc. to suppress power generation of the alternator (hereinafter, this situation is referred to as low output), and deceleration If the adjustment voltage is set to a high value at some time and power generation is promoted (hereinafter such a scene is referred to as high output), the engine load due to the power generation of the alternator can be reduced, and the fuel consumption of the engine can be reduced. .

  At the time of low output, for example, it is conceivable to set the alternator adjustment voltage based on the difference between the state of charge (SOC) of the battery and the target value of SOC (for example, about 90 [%]) ( (See the following formula (1)). In the formula, Vreg is an alternator adjustment voltage, Vmin is a lower limit voltage (for example, about 12.5 [V]), K1 is a proportional constant, SOCtarget is a target value of SOC, and SOCnew is the latest SOC value. Value.

  Vreg = Vmin + K1 (SOCtarget-SOCnew) (1)

  Such control is specifically implemented (for example, refer nonpatent literature 1).

  Further, as a simpler control, it is conceivable to set the alternator adjustment voltage to a constant value at high output and low output, respectively. In this case, Vreg = Vmax (for example, about 14.5 [V]) at high output, and Vreg = Vmin (for example, about 12.5 [V]) at low output. However, Vreg = Vmax is set for a certain time after the engine is started (for example, about 5 [min]), and Vreg = Vmax is maintained even after the state of Vreg = Vmin is continued for a certain time (for example, about 5 [min]). May be equal.

Toyota Motor Co., Ltd., “Mark X Zio New Model Manual (Part No. NM08B0J)”, Toyota Motor Corporation Service Engineering Department, issued on December 3, 2007, Chapter 2, Engines, p2-233-244

  However, when the alternator adjustment voltage is determined by comparing the SOC with the target value, a current sensor or the like for calculating the SOC is essential, and in addition, it is necessary to perform an operation taking into account the battery temperature, etc. In addition, the cost becomes high. Accordingly, it may be difficult to install the vehicle in an economy car class.

  Therefore, there is a possibility that a device that does not calculate the SOC by omitting the current sensor exists. However, as described above, when the alternator adjustment voltage is set to a constant value at high output and low output, respectively, Since the state of charge and the alternator adjustment voltage do not link accurately, the battery may be in an overdischarged state, which may shorten the battery life or reduce the vehicle restartability.

  The present invention is for solving such problems, and a main object thereof is to provide a vehicle power generation control device capable of appropriately controlling the output of an alternator with a simple configuration.

In order to achieve the above object, one embodiment of the present invention provides:
An alternator mounted on a vehicle and supplying power to an in-vehicle device including a battery;
Vehicle state acquisition means for acquiring a vehicle state including a vehicle speed;
Adjustment voltage determination means for determining the adjustment voltage of the alternator using different criteria at the time of high output and low output of the alternator determined based on the vehicle state acquired by the vehicle state acquisition means;
A vehicle power generation control device comprising:
The adjustment voltage determining means, when the output of the alternator is low, the adjustment voltage of the alternator decreases as the integrated value of the difference between the adjustment voltage of the alternator relative to a predetermined time point and the predetermined voltage increases. The adjustment voltage of the alternator tends to increase as the integrated value decreases, and the adjustment voltage of the alternator is determined.
This is a vehicle power generation control device.

  According to this aspect of the invention, the adjustment voltage of the alternator decreases as the integrated value of the difference between the adjustment voltage of the alternator relative to the predetermined time point and the predetermined voltage increases, and the alternator adjustment decreases as the integrated value of the difference decreases. In order to determine the alternator adjustment voltage with a tendency to increase in voltage, the adjustment voltage increases after the alternator adjustment voltage continues to be low, and the adjustment voltage increases after the alternator adjustment voltage continues to be high. The alternator is controlled to be low. As a result, the state of charge of the battery and the adjustment voltage of the alternator are accurately linked, and the battery can be protected and the restartability of the vehicle can be improved. Further, since a current sensor is not required and complicated SOC calculation or the like is unnecessary, the system can be simplified and reduced in cost. Therefore, it can be easily mounted on an economy car class vehicle.

  As described above, the output of the alternator can be appropriately controlled with a simple configuration.

In one embodiment of the present invention,
The predetermined voltage is preferably an open-circuit voltage when the battery is fully charged.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power generation control apparatus for vehicles which can control the output of an alternator appropriately by simple structure can be provided.

1 is a system configuration example of a vehicle power generation control device 1 according to an embodiment of the present invention. It is a figure which shows the relationship (trend) between charging / discharging integrated value and the adjustment voltage Vreg of the alternator. It is a flowchart which shows the flow of the characteristic process which power generation control ECU30 performs.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  The following describes one embodiment of the present invention. FIG. 1 is a system configuration example of a vehicle power generation control device 1 according to an embodiment of the present invention. The vehicular power generation control device 1 includes an alternator 10, a vehicle speed sensor 20, and a power generation control ECU (Electronic Control Unit) 30 as main components.

  The alternator 10 generates power by the output of the engine and supplies power to the battery 40 and other in-vehicle devices. As the battery 40, for example, a lead storage battery having an open-circuit voltage of about 12.8 [V] when fully charged is used.

  The alternator 10 is a three-phase alternating current generator that generates a three-phase alternating current by electromagnetic induction between the stator and the rotor, a full-wave rectifier circuit that converts the three-phase alternating current output from the three-phase alternating current generator into a direct current, An IC regulator or the like for controlling the generated voltage of the three-phase AC generator by adjusting the excitation current supplied to the electromagnet (field coil) of the rotor is incorporated.

  The rotor of the three-phase AC generator is connected to a crankshaft that is an output shaft of the engine via a belt or a pulley.

  A power generation control signal (for example, a voltage signal) for the IC regulator is input from the power generation control ECU 30. The IC regulator includes a comparator that compares the generated voltage of the three-phase AC generator with the voltage value of the power generation control signal, a transistor that is turned on / off based on the output of the comparator, and the like.

  If the generated voltage of the three-phase AC generator is lower than the voltage value of the power generation control signal, the transistor outputs an ON signal, an exciting current flows through the field coil to generate an electromotive force, and the generated voltage of the three-phase AC generator Rises. On the other hand, if the generated voltage of the three-phase AC generator exceeds the voltage value of the power generation control signal, the transistor outputs an off signal, the excitation current does not flow to the field coil, and the generated voltage of the three-phase AC generator decreases. To do.

  The vehicle speed sensor 20 includes, for example, a wheel speed sensor attached to each wheel of the vehicle and a skid control computer, and the skid control computer converts the wheel speed pulse signal output from the wheel speed sensor into a vehicle speed rectangular wave pulse signal (vehicle speed signal). Convert and output. The wheel speed sensor includes, for example, a magnetic rotor in which rubber is filled with magnetic powder and positive and negative electrodes are alternately arranged in the circumferential direction, and an active sensor that detects a change in magnetic field due to the rotation of the magnetic rotor.

  The power generation control ECU 30 is, for example, a microcomputer in which a ROM (Read Only Memory), a RAM (Random Access Memory), and the like are connected to each other via a bus with a CPU (Central Processing Unit) as a center. A storage device such as a disc drive (DVD), a digital versatile disk (DVD) drive, a compact disc-recordable (CD-R) drive, and an electronically erasable and programmable read only memory (EEPROM), an I / O port, a timer, a counter, and the like are provided. The ROM stores programs and data executed by the CPU. The power generation control ECU 40 may be integrated with another control device provided in the vehicle, such as an engine control ECU or a battery control ECU.

  Further, the power generation control ECU 30 determines whether the output of the alternator 10 is set to a high output or a low output based on the output of the vehicle speed sensor 20. Specifically, for example, the output of the alternator 10 is output for a fixed time (for example, about 5 [min]) from the engine start and during deceleration (when the value indicated by the vehicle speed signal output from the vehicle speed sensor 20 is decreasing). High output. On the other hand, the output of the alternator 10 is set to a low output when the vehicle is stopped, accelerated, and driven at a constant speed. By such control, the engine load due to the power generation of the alternator 10 can be reduced, and the fuel consumption of the engine can be reduced. Note that the method for determining the high output and the low output is not limited to this, and it may be determined whether the output is high or low considering the accelerator opening, the shift position, and the like.

  The power generation control ECU 30 determines that the adjustment voltage Vreg of the alternator 10 is Vreg = Vmax (for example, about 14.5 [V]) when the output of the alternator 10 is determined to be high.

  On the other hand, at the time of low output when the output of the alternator 10 is determined to be low, for example, the difference between the adjustment voltage Vreg of the alternator 10 based on a predetermined time point after a certain period of time has elapsed from the engine start and the predetermined voltage Vo. The adjustment voltage Vreg of the alternator 10 is determined such that the adjustment voltage Vreg of the alternator 10 decreases as the integrated value (charge / discharge integrated value) increases, and the adjustment voltage Vreg of the alternator 10 increases as the integrated charge / discharge value decreases.

  Here, it is preferable that the predetermined voltage Vo is an open-circuit voltage when the battery 40 is fully charged.

  The power generation control ECU 30 calculates a charge / discharge integrated value {∫ (Vreg−Vo) dt} based on a predetermined time point in a predetermined cycle (for example, every several [ms]). Then, the adjustment voltage Vreg of the alternator 10 is determined according to the following equations (2) to (4).

∫ (Vreg−Vo) dt ≧ A → Vreg = Vmin (2)
A> ∫ (Vreg−Vo) dt ≧ B → Vreg = Vmin−K2 · {A−∫ (Vreg−Vo) dt} (3)
B> ∫ (Vreg−Vo) dt → Vreg = Vmax (4)

  Here, A and B are determination reference values (A> B). K2 is a value indicating the slope of Vreg with respect to the change of the charge / discharge integrated value, and is equal to {(Vmax−Vmin) / (A−B)}.

  As a result, the relationship between the charge / discharge integrated value and the adjustment voltage Vreg of the alternator 10 shows a tendency as shown in FIG. As a result, after the state where the adjustment voltage Vreg of the alternator 10 is low, the adjustment voltage Vreg of the alternator 10 becomes high, and after the state where the adjustment voltage Vreg of the alternator 10 is high, the adjustment voltage Vreg of the alternator 10 becomes high. The alternator 10 is controlled so as to be lowered.

  FIG. 3 is a flowchart showing a flow of characteristic processing executed by the power generation control ECU 30. This flow is repeatedly executed at predetermined intervals, for example, and is forcibly terminated when the engine is stopped.

  First, referring to the value of the internal timer or the like, it is determined whether or not a certain time has elapsed since the engine was started (S100).

  If the fixed time has not elapsed since the engine start, the fixed time non-elapsed flag is set in a temporary storage device such as a register (S102). Then, the adjustment voltage Vreg of the alternator 10 is determined to be Vmax (S104), and one routine of this flow is finished.

  If it is determined that a certain time has elapsed since the engine was started, it is determined whether a certain time non-elapsed flag is set (S106). If the fixed time non-elapsed flag is set, it is determined that the fixed time has passed from the previous flow to the current flow, so the internal timer value at that time is stored in a register, etc. to charge / discharge The calculation start time of the integrated value {Ｖ (Vreg−Vo) dt} is set (S108), and the fixed time non-elapsed flag is deleted (S110).

  Then, a charge / discharge integrated value {∫ (Vreg−Vo) dt} is calculated (S112).

  Next, with reference to the output of the vehicle speed sensor 20, it is determined whether or not the vehicle is decelerating (S114). If it is determined that the vehicle is decelerating, the adjustment voltage Vreg of the alternator 10 is determined to be Vmax (S104), and one routine of this flow is terminated.

  On the other hand, when it is determined that the vehicle is not decelerating (specifically, when the vehicle is stopping, accelerating, or traveling at a constant speed), the charge / discharge integrated value {∫ (Vreg− Vo) dt}, the adjustment voltage Vreg of the alternator 10 decreases as the charge / discharge integrated value increases, and the adjustment voltage Vreg of the alternator 10 tends to increase as the charge / discharge integrated value decreases. Is determined (S116), and one routine of this flow is terminated. Specifically, for example, the adjustment voltage Vreg of the alternator 10 is determined according to the above equations (2) to (4).

  By such processing, after the state where the adjustment voltage Vreg of the alternator 10 is low, the adjustment voltage Vreg of the alternator 10 becomes high, and after the state where the adjustment voltage Vreg of the alternator 10 is high, the adjustment voltage Vreg of the alternator 10 continues. The alternator 10 is controlled so as to be low. As a result, the state of charge of the battery 40 and the adjustment voltage Vreg of the alternator 10 are accurately linked, so that the battery 40 can be protected and the restartability of the vehicle can be improved.

  Further, since the vehicle power generation control device 1 according to the present embodiment does not require a current sensor and does not require complicated SOC calculation or the like, the system can be simplified and reduced in cost. Therefore, it can be easily mounted on an economy car class vehicle.

  According to the vehicle power generation control device 1 of the present embodiment described above, the output of the alternator 10 can be appropriately controlled with a simple configuration.

  The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. And substitutions can be added.

  For example, the method for determining the adjustment voltage Vreg of the alternator 10 described with reference to equations (2) to (4) and FIG. 2 is merely an example, and the adjustment voltage Vreg of the alternator 10 decreases as the charge / discharge integrated value increases. Any control tendency may be adopted as long as the adjustment voltage Vreg of the alternator 10 becomes higher as the charge / discharge integrated value becomes smaller. For example, the adjustment voltage Vreg may be changed from Vmin to Vmax in a curved line shape or a staircase shape.

  In addition, a value different from the open-circuit voltage when the battery 40 is fully charged may be used as the predetermined voltage Vo serving as a reference for the charge / discharge integrated value.

  The present invention can be used in the automobile manufacturing industry, the automobile parts manufacturing industry, and the like.

DESCRIPTION OF SYMBOLS 1 Vehicle charging control apparatus 10 Alternator 20 Vehicle speed sensor 30 Electric power generation control ECU
40 battery

Claims (2)

An alternator mounted on a vehicle and supplying power to an in-vehicle device including a battery;
Vehicle state acquisition means for acquiring a vehicle state including a vehicle speed;
Adjustment voltage determination means for determining the adjustment voltage of the alternator using different criteria at the time of high output and low output of the alternator determined based on the vehicle state acquired by the vehicle state acquisition means;
A vehicle power generation control device comprising:
The adjustment voltage determining means, when the output of the alternator is low, the adjustment voltage of the alternator decreases as the integrated value of the difference between the adjustment voltage of the alternator relative to a predetermined time point and the predetermined voltage increases. The adjustment voltage of the alternator tends to increase as the integrated value decreases, and the adjustment voltage of the alternator is determined.
Vehicle power generation control device. The predetermined voltage is an open voltage when the battery is fully charged.
The vehicle power generation control device according to claim 1.

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