JP2010045869A - Power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply apparatus that accurately controls power supply by correcting an error, which arises in a current sensor, even when a battery shifts from its charge state to its discharge state and that the direction of a current detected by a current sensor inverts. <P>SOLUTION: It determines one correction, which is used for correction from a table 12 of corrections that are stored beforehand in a memory 11, being associated with detected values, based on the detected value of a charge current by a current sensor 6 before stop of power supply and the detected value of a charge current after stop of power supply, when the power supply from an alternator 1 to a battery 3 is stopped, and corrects the detected value of the current sensor 6. Moreover, it computes the remaining capacity and the remaining time of the battery 3, using the corrected detected value, and performs the warning by a warning lamp 14, the power supply stoppage by a switch 4, etc., when the remaining time becomes shorter than a specified time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power supply device that includes a current sensor that detects a charging current from a generator to a battery and a discharging current from a battery to a load, and that supplies power according to the detection result of the current sensor.

  In recent years, from the viewpoints of vehicle safety, convenience, comfort, product power, and the like, the number of electrical devices mounted on vehicles has been increasing. For example, in addition to devices such as an electric brake and electric power steering that operate while the vehicle is running, devices such as a car navigation device that operates even when the vehicle is stopped, a remote locking and unlocking system, and a lamp are mounted on the vehicle. Electric equipment that operates while the vehicle is stopped is supplied with electric power from a battery mounted on the vehicle. However, the electric power that can be stored in the battery is finite, and so-called battery increase occurs when an electric device is used for a long time while the vehicle is stopped. As the number of electrical devices mounted on a vehicle increases, there is a problem that the possibility of battery exhaustion increases.

  In order to solve the above problem, there is a measure for starting time measurement by a timer after stopping the engine of the vehicle and stopping supply of electric power from the battery after a predetermined time has elapsed. However, if the remaining capacity of the battery is small when the engine is stopped, the battery may run out if the set time of the timer is long. If the set time of the timer is shortened in consideration of the case where the remaining capacity of the battery is small, the user can use electric devices mounted on the vehicle only for a short period after the engine is stopped, and convenience is reduced.

In Patent Document 1, the state of charge of a battery is detected, and the intermittent operation time for intermittent driving of the load in the automobile is calculated according to the operation guarantee period input by the user. An in-vehicle power management device that can prevent the battery from running out in a state has been proposed. In this in-vehicle power management device, the battery will not run out at least during the operation guarantee period input by the user.
JP 2006-188139 A

  By controlling the power supply according to the remaining capacity of the battery as in the in-vehicle power management device described in Patent Document 1, it is possible to prevent the battery from running out after the engine is stopped. The remaining capacity of the battery can be obtained by detecting the current flowing from the generator to the battery and the current flowing from the battery to the load with a current sensor and calculating the integrated value of the detected values. For this reason, in order to acquire the remaining capacity of the battery with high accuracy, it is necessary to increase the detection accuracy of the current sensor.

  The inventor of the present application, for example, when the current is flowing from the generator to the battery and charging is performed, and when the engine is stopped and the current flows from the battery to the load, that is, when the direction of current flow is reversed. In addition, it has been found that an error occurs in the detection value of the current sensor. If an error occurs in the detection value of the current sensor, the accuracy of the remaining capacity of the battery calculated based on the integral value decreases. Therefore, the power corresponding to the remaining capacity of the battery as in the in-vehicle power management device described in Patent Document 1 Even if the supply is controlled, there is a possibility that the battery cannot be prevented from running out.

  The present invention has been made in view of such circumstances, and the object of the present invention is when the battery transitions from the charged state to the discharged state and the direction of the current detected by the current sensor is reversed. It is another object of the present invention to provide a power supply apparatus that can correct an error generated in a current sensor and perform accurate power supply control.

  A power supply device according to the present invention includes a generator for supplying generated power to a load, a battery for storing the power generated by the generator, and supplying the stored power to the load, and the generator from the generator In a power supply device comprising a current sensor for detecting a charging current to the battery and a discharging current from the battery to the load, stop determination means for determining stoppage of power supply of the generator, and power supply of the generator Is associated with the detection value before stopping and the detection value before stopping the power supply of the generator and the detection value after stopping Correction value storage means for storing a correction value for the detection value of the current sensor, and a detection value before stop acquired by the detection value acquisition means before stop after the power supply to the generator is stopped and A correction value determining means for determining a correction value used for correcting the detected value from the correction value stored in the correction value storage means in accordance with a detection value detected by the current sensor; and after the power supply to the generator is stopped And correction means for correcting the detection value of the current sensor in accordance with the correction value determined by the correction value determination means.

  In addition, the power supply device according to the present invention includes a remaining capacity calculation unit that calculates a remaining capacity of power stored in the battery, a detection value corrected by the correction unit, and a remaining capacity calculated by the remaining capacity calculation unit. A remaining time calculating unit that calculates a remaining time during which power can be supplied from the battery to the load, and a warning unit that issues a warning when the remaining time calculated by the remaining time calculating unit is shorter than a predetermined time. It is characterized by.

  In addition, the power supply device according to the present invention includes a remaining capacity calculation unit that calculates a remaining capacity of power stored in the battery, a detection value corrected by the correction unit, and a remaining capacity calculated by the remaining capacity calculation unit. And a remaining time calculating means for calculating a remaining time during which power can be supplied from the battery to the load, and a power supply from the battery to the load when the remaining time calculated by the remaining time calculating means is shorter than a predetermined time. And a stop means for stopping the operation.

  Further, the power supply device according to the present invention is such that the current sensor continuously or intermittently detects a current, further comprising a detection value storage means for storing a detection value of the current sensor, and the stop The pre-detection value acquisition unit acquires the detection value before the power supply is stopped from the detection value storage unit.

  In the power supply apparatus according to the present invention, the generator generates power in accordance with the operation of the engine of the vehicle, and obtains a control signal for starting / stopping the engine. The stop determination unit is configured to determine whether to stop the power supply of the generator according to the operation state of the engine based on the control signal acquired by the engine control signal acquisition unit. And

In the present invention, when the power supply from the generator to the battery is stopped, the detected values by the current sensor before the power supply is stopped and the detected values after the power supply is stopped are associated with both detected values. One correction value used for correction of the detection value is determined from a plurality of correction values stored in advance, and the detection value of the current sensor is corrected.
The inventor of the present application, when the battery transitions from the charged state to the discharged state and the direction of the current detected by the current sensor is reversed, the error that occurs in the detected value of the current sensor after the inversion is the amount of the charging current before the inversion It has been found that it depends on the amount of discharge current after inversion. Therefore, the error of the detection value of the current sensor with respect to the charging current and the discharging current is measured in advance, and the correction value for correcting this error is stored in advance by the power supply apparatus. Accordingly, the power supply device can detect the discharge current by the current sensor, correct the detected value based on the correction value, and can detect the discharge current with high accuracy.

In the present invention, the remaining capacity of the battery is calculated, and the remaining time during which the battery can be supplied is calculated according to the corrected detected current value. The remaining capacity of the battery can be calculated, for example, from the difference between the integrated value of the charging current flowing into the battery and the integrated value of the discharging current flowing out of the battery. For example, it can also be calculated based on the voltage of the battery. The remaining time for which power can be supplied is, for example, the difference between the capacity of the battery required for starting the engine and the current remaining capacity of the battery as the usable capacity of the battery, and the usable capacity and the current discharge current amount The remaining time can be obtained by comparison.
When the remaining time becomes shorter than the predetermined time, the power supply device issues a warning with a warning lamp or a warning sound, thereby allowing the user to recognize a decrease in the remaining capacity of the battery. Further, when the remaining time becomes shorter than the predetermined time, the power supply device stops the power supply from the battery to the load, so that the battery can be prevented from running out.

  In the present invention, the current flowing into and out of the battery is detected continuously or intermittently by the current sensor, and the detected value is stored. The power supply device that detects that the power supply from the generator to the battery has been stopped and the battery has transitioned from the charged state to the discharged state reads the stored current sensor detection value, thereby stopping the power supply to the battery. The detection value of the current sensor before being performed can be acquired.

  In the present invention, the generator is configured to generate power in accordance with the operation of the engine. Whether or not the power supply from the generator to the battery has been stopped can be determined by obtaining a control signal (for example, a signal given from an ignition switch) related to engine start / stop. For example, the power supply device can determine that the power is supplied from the generator to the battery when the engine is operating, and the power is charged, and when the engine is stopped. It can be determined that power is not being supplied from the generator to the battery, and the battery power is being supplied to the load.

  In the case of the present invention, when the power supply from the generator to the battery is stopped, both detection values are supported based on the detection value by the current sensor before the power supply is stopped and the detection value after the power supply is stopped. In addition, by determining a correction value from a plurality of correction values stored in advance and correcting the detection value of the current sensor, the remaining battery capacity or The remaining time and the like can be accurately calculated, and the power supply apparatus can perform highly reliable power supply control processing. For this reason, it is possible to reliably prevent the battery from running up when the vehicle-mounted device is continuously used after the vehicle engine is stopped.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram showing a configuration of a power supply apparatus according to the present invention. In the figure, reference numeral 1 denotes an alternator, which generates electric power by converting energy of rotational motion by an engine 2 mounted on a vehicle into electric energy. The alternator 1 has a rectifier circuit (not shown) inside, and converts the generated AC power into DC power and outputs it.

  The electric power generated by the alternator 1 is supplied to a battery 3 and various loads 5 mounted on the vehicle via a power line. The battery 3 is a secondary battery such as a lead storage battery, for example. When power is supplied from the alternator 1, the supplied power can be stored, and when power is not supplied from the alternator 1. Can supply the stored power to the load 5.

  In the power supply path between the battery 3 and the alternator 1 and the load 5, a current for detecting a current (charge current) flowing from the alternator 1 to the battery 3 and a current (discharge current) flowing from the battery 3 to the load 5 is detected. A sensor 6 is arranged. The current sensor 6 is a sensor that performs current detection in a non-contact manner, for example, by detecting a magnetic field generated by the current with a Hall element. Given. In the present embodiment, the current sensor 6 sets the direction in which the current flows out from the battery 3 (the direction of the solid arrow in FIG. 1) as the positive direction, sets the detected value of the current flowing in this direction as a positive value, and reverse The detected value of the current flowing through is supplied to the control unit 10 as a negative value.

  In the power supply path between the alternator 1 and the battery 3 and the load 5, a switch 4 for connecting / cutting off the power supply path is disposed. Switching of connection / disconnection of the switch 4 is controlled by the control unit 10. When the power supply path is connected by the switch 4, power from the alternator 1 or the battery 3 is supplied to the load 5.

  The load 5 is, for example, an electric device such as a lamp, an air conditioner, a car navigation device, and various ECUs (Electronic Control Units) mounted on the vehicle. In the present embodiment, the vehicle engine 2 is stopped. It is assumed that the electric device can be operated even in a state. The load 5 includes an electric device connected to a vehicle accessory socket (cigar socket). The load 5 is supplied with electric power generated by the alternator 1 when the engine 2 of the vehicle is operating, and the battery 3 is accumulated when the engine 2 is stopped and the alternator 1 cannot generate electric power. Power is supplied.

  The control unit 10 performs control processing of the switch 4 and the warning lamp 14 and various arithmetic processing, and is specifically configured by a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). . The control unit 10 is provided with a signal (IG signal) for notifying the value detected by the current sensor 6 and the state of the ignition switch (IG switch) 13 of the vehicle. Further, the control unit 10 can read and process various data stored in the storage unit 11, and can store data generated during the processing in the storage unit 11.

  The IG switch 13 receives an operation by a user for starting / stopping the engine 2 of the vehicle. For example, when the IG switch 13 is configured to start / stop the engine 2 by attaching a vehicle key and the user performs a rotation operation, the key rotation position is notified from the IG switch 13 to the control unit 10 as an IG signal. Thus, the control unit 10 can determine whether the engine 2 is operating or stopped.

  The storage unit 11 is configured by a nonvolatile memory element such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory, for example, and stores various data required when the control unit 10 performs processing. In addition, data provided from the control unit 10 can be stored. The storage unit 11 stores a correction value table 12 to be described later in advance, and the control unit 10 reads the correction value table 12 from the storage unit 11 and corrects the detection value of the current sensor 6. it can.

  The warning lamp 14 is, for example, a lamp arranged on the instrument panel of the vehicle, and gives a warning to the user by lighting or blinking. The warning light 14 is turned on and off by the control unit 10.

  In the power supply apparatus according to the present invention, the control unit 10 can calculate the remaining capacity of the battery 3 based on the detection value of the current sensor 6. Since the integrated value of the charging current flowing into the battery 3 is the accumulated capacity of the electric power, and the integrated value of the discharging current flowing out of the battery 3 is the used electric capacity, the integrated value of the current detected by the current sensor 6 is By calculating and subtracting from the initial capacity of the battery 3, the control unit 10 can calculate the remaining capacity of the battery 3. However, the remaining capacity may be calculated or acquired by other methods such as detecting the voltage of the battery 3 and acquiring the remaining capacity.

  Further, the power supply device according to the present invention is based on the detection value of the current sensor 6 and the time until the remaining capacity of the battery 3 falls below a predetermined capacity when the current power consumption by the load 5 is continued (remaining time). ) Can be calculated. The predetermined capacity of the battery 3 that defines the remaining time can be set in advance, for example, a capacity necessary for starting the engine 2 of the vehicle. The control unit 10 can calculate the remaining time by comparing the available capacity obtained by subtracting the predetermined capacity from the remaining capacity of the battery 3 at the current time with the detected value of the current sensor 6 at the current time.

  When the calculated remaining time is less than a predetermined time such as 1 hour, the control unit 10 lights the warning lamp 14 to warn the user. Further, when the remaining time is less than a predetermined time such as 30 minutes, the control unit 10 interrupts the current path from the battery 3 to the load 5 by the switch 4 and stops the power supply.

  In addition, the power supply device according to the present invention has a function of correcting an error in the detected value of the current detected by the current sensor 6, and is based on the detected value obtained by correcting the calculation of the remaining capacity and the remaining time. Thus, the warning to the user by the warning lamp 14 and the stop of the power supply by the interruption of the switch 4 can be accurately and reliably performed. Hereinafter, the correction process of the detection value of the current sensor 6 performed by the power supply device will be described.

  The inventor of the present application supplies power from the alternator 1 by stopping the engine 2 from a state where the battery 3 is charged (charged state) when power is supplied from the alternator 1 and charging current flows into the battery 3. It was found that when the electric power accumulated in the battery 3 is supplied to the load 5 and the discharge current flows out from the battery 3 (discharge state), an error occurs in the detection value of the current sensor 6.

  2A and 2B are schematic diagrams for explaining a method of measuring an error occurring in the detection value of the current sensor 6. FIG. 2A shows an error measurement circuit, and FIG. 2B shows an applied current waveform at the time of measurement. is there. In this measurement circuit, a current sensor 6 is connected in series to the battery 3 to control a current i charged / discharged with respect to the battery 3 (the direction of the discharge current flowing out from the battery 3 is positive). The difference between the value detected by the sensor 6 and the actual charge / discharge current i was measured. The current i is controlled by discharging the battery 3 (discharge current 5 [A]), charging the battery 3 with a constant current (charge current I1) during a fixed period (charge period T1), and thereafter The direction of the current i was reversed, and a constant current (discharge current I2) was discharged from the battery 3 during the subsequent period (discharge period T2) to discharge.

  3 to 5 are graphs showing measurement results of errors occurring in the detection values of the current sensor 6, where the horizontal axis is time [sec] and the vertical axis is the error [A] of the current sensor 6. FIG. 3 shows the result of measuring the error of the detection value of the current sensor 6 (actual current i−detection value of the current sensor 6) with the charging period T1 = 1 minute, the charging current I1 = 10 A, and the discharge current I2 = 1 A. FIG. 4 shows the results of measuring the error with the charging period T1 = 1 minute, the charging current I1 = 40 A, and the discharging current I2 = 1 A. FIG. 5 shows the charging period T1 = 1 minute, the charging current I1. It is the result of measuring the error with = 10 A and discharge current I2 = 0.5 A.

  Comparing the error of the current sensor 6 after the end of the charging period T1 and the transition to the discharging period T2 in FIGS. 3 and 4, the error is about −0.16 A in the case of FIG. 3 where the charging current I1 is small. On the other hand, in the case of FIG. 4 where the charging current I1 is large, the error is about −0.21 A, and it has been found that the error of the current sensor 6 changes according to the charging current I1 flowing during the charging period T1. Although illustration of the measurement results is omitted, even if the length of the charging period T1 is changed, if the charging current I1 and the discharging current I2 are the same, the error of the current sensor 6 is substantially the same. It was.

  Further, when the error of the current sensor 6 after the end of the charging period T1 and the transition to the discharging period T2 is compared in FIGS. 3 and 5, the error is about −0.16 A in the case of FIG. 3 where the discharging current I2 is large. On the other hand, in the case of FIG. 5 where the discharge current I2 is small, the error is about −0.11 A, and it has been found that the error of the current sensor 6 changes according to the discharge current I2.

  From these facts, when the direction of the current flowing through the current sensor 6 is reversed, it is estimated that an error generated in the detection result of the current after the inversion is determined by the current amount before the inversion and the current amount after the inversion. . Therefore, an error in the detected value of the current sensor 6 with respect to the current amount before inversion and the current amount after inversion, that is, the detected value of the current sensor 6 with respect to the charging current before the power supply is stopped by the alternator 1 and the discharging current after the power supply is stopped. An error is measured in advance, and the correction value for canceling the measured error and correcting the detected value to the original amount of current is calculated in advance.

  The power supply apparatus according to the present invention stores a correction value table 12 in which the calculated correction value is associated with the charging current before the power supply is stopped and the discharge current after the power supply is stopped in the storage unit 11 in advance. After the power supply by 1 is stopped, the detection value of the current sensor 6 is corrected using the correction value table 12, thereby increasing the detection accuracy of the discharge current by the current sensor 6.

  FIG. 6 is a schematic diagram for explaining the correction values stored in the correction value table 12, and illustrates an example of numerical values stored in the correction value table 12 in a graph. From the above measurement results, the larger the charging current before the power supply is stopped by the alternator 1, the larger the error in the detected value of the discharge current by the current sensor 6 after the power supply is stopped. Therefore, the value of the correction value for correcting this error is also large. Moreover, since the error of the detection value by the current sensor 6 increases as the discharge current after the power supply is stopped, the value of the correction value for correcting this error is also large. The control unit 10 can perform correction by determining one correction value to be used for correction from the correction value table 12 and subtracting this correction value from the detection value of the current sensor 6.

  When power is supplied from the alternator 1, the control unit 10 of the power supply device continuously detects the charging current by the current sensor 6 and stores the detected value in the storage unit 11. When the engine 2 is stopped and the power supply from the alternator 1 is stopped, the control unit 10 acquires the detected value of the charging current immediately before the power supply is stopped from the storage unit 11. Thereafter, each time the discharge current is detected by the current sensor 6, the control is performed from the correction value table 12 stored in the storage unit 11 based on the detection value of the charging current immediately before the power supply is stopped and the detection value of the discharge current. The unit 10 determines one correction value and corrects the detection value of the discharge current.

  FIG. 7 is a flowchart showing a procedure of processing performed by the power supply apparatus according to the present invention, and shows processing performed by the control unit 10 after the engine 1 is started. First, the control unit 10 acquires an IG signal output from the IG switch 13 (step S1), determines whether or not the engine 2 is stopped based on the IG signal (step S2), and the electric power from the alternator 1 is determined. It is determined whether or not the supply is stopped.

  When the engine 2 is not stopped (S2: NO), that is, when power is supplied from the alternator 1, the control unit 10 acquires a detection value of the charging current to the battery 3 by the current sensor 6 ( Step S3), the acquired detection value is stored in the storage unit 11 (Step S4), and the remaining capacity of the battery 3 is calculated based on the acquired detection value (Step S5). Thereafter, the control unit 10 returns to step S1, and repeatedly stores the detection value of the current sensor 6 and calculates the remaining capacity of the battery 3 until the engine 2 stops.

  When the engine 2 is stopped (S2: YES), that is, when the power supply from the alternator 1 is not performed, the control unit 10 detects a detected value for correcting the detected value of the discharge current of the battery 3 by the current sensor 6. Correction processing is performed (step S6).

  FIG. 8 is a flowchart showing a procedure of detection value correction processing performed by the power supply apparatus according to the present invention, and is processing performed by the control unit 10 in step S6 of the flowchart shown in FIG. In the detection value correction processing, first, the control unit 10 acquires the detection value of the charging current detected by the current sensor 6 immediately before the power supply of the alternator 1 is stopped from the storage unit 11 (step S21), and the correction value from the storage unit 11 The table 12 is read (step S22), and detection by the power sensor 6 is performed to obtain a detected value of the discharge current (step S23).

  Next, the control unit 10 refers to the correction table read in step S22 based on the detected value of the charging current just before the power supply stop acquired in step S21 and the detected value of the discharge current acquired in step S23. Then, one correction value used for correction is determined (step S24). The control unit 10 corrects the detection value of the current sensor 6 acquired in step S23 using the correction value determined in step S24 (step S25), and ends the detection value correction process.

  After the detection value correction process is completed, the control unit 10 calculates the remaining capacity of the battery 3 using the corrected detection value (step S7), and the remaining capacity of the battery 3 is calculated from the corrected detection value and the calculated remaining time. The remaining time until it falls below the predetermined capacity is further calculated (step S8). The control unit 10 determines whether or not the calculated remaining time is shorter than 1 hour (step S9). If the remaining time is 1 hour or more (S9: NO), the control unit 10 returns to step S1 and repeats the above processing. . When the remaining time is shorter than 1 hour (S9: YES), the control unit 10 turns on the warning lamp 14 (step S10), and further determines whether the remaining time is shorter than 30 minutes (step S11). When the remaining time is 30 minutes or more (S11: NO), the control unit 10 returns to step S1 and repeats the above-described processing. When the remaining time is shorter than 30 minutes (S11: YES), the control unit 10 controls the switch 4 to cut off the power supply path, thereby stopping the power supply from the battery 3 to the load 5 (step S12). The process is terminated.

  In the procedure shown in the flowcharts of FIGS. 7 and 8, the correction process for the detection value of the current sensor 6 is continuously performed after the engine 2 of the vehicle is stopped. However, the present invention is not limited to this. The detection value correction process may not be performed after a certain time has elapsed since the engine 2 was stopped, and the remaining capacity of the battery 3 may be calculated using the detection value of the current sensor 6 as it is. In addition, for example, when the current flowing to the load 5 becomes sufficiently small after the engine 2 is stopped, that is, when the detected value of the current by the current sensor 6 becomes a predetermined value or less, the detected value of the current sensor 6 is similarly changed It is good also as a structure which does not perform a correction process.

  In the power supply device having the above configuration, when the power supply from the alternator 1 to the battery 3 is stopped, the detected value of the charging current by the current sensor 6 before the power supply is stopped and the discharge current after the power supply is stopped. Based on the detection values, one correction value used for correction is determined from the correction value table 12 stored in advance in the storage unit 11 in association with both detection values, and the detection value of the current sensor 6 is corrected. As a result, the power supply apparatus can perform processing related to power supply using an accurate detection value of the discharge current with the error corrected. The power supply device can accurately calculate the remaining capacity and remaining time of the battery 3 using the corrected detection value, and when the remaining time becomes shorter than a predetermined time, the warning by the warning lamp 14 and the power by the switch 4 By stopping supply or the like, it is possible to reliably prevent the battery from running out.

  In the present embodiment, whether or not the power supply from the alternator 1 is stopped is determined based on the IG signal output from the IG switch 13, but the present invention is not limited to this. You may determine the stop of electric power supply by other methods, such as acquiring the operating state of the engine 2 from ECU which controls. Further, the correction value is stored in the correction value table 12, and the control unit 10 determines one correction value based on the detection value before the power supply stop and the detection value after the stop of the power supply, and the detection value after the stop is obtained. The correction is performed using the correction value, but the present invention is not limited to this. The corrected value is stored in the correction table 12, and the control unit is based on the detection value before the power supply is stopped and the detection value after the power supply is stopped. It is good also as a structure which acquires the detection value by which 10 was correct | amended directly. Further, when correction based on the correction value is performed, the correction value is subtracted from the detection value of the current sensor 6, but the present invention is not limited to this, and addition, multiplication, division, or correction value correction is performed on the detection value. It is good also as a structure which correct | amends by performing another calculation.

  Further, the remaining time until the remaining capacity of the battery 3 falls below a predetermined capacity is calculated, and the warning by the warning lamp 14 and the power supply stop by the switch 4 are performed according to the remaining time. However, the present invention is not limited to this. Alternatively, a warning and power supply stop may be performed according to the remaining capacity of the battery 3. In addition, the warning is given to the user by turning on the warning light 14, but the present invention is not limited to this. The warning may be given by a warning sound by a buzzer, and the display is mounted on the vehicle. May be configured to issue a warning by displaying a warning message on the display, or may be configured to issue a warning by other methods. Moreover, although the power supply device is mounted on the vehicle, the present invention is not limited to this, and the power supply device of the present invention may be mounted on another system including a generator and a battery.

It is a block diagram which shows the structure of the power supply apparatus which concerns on this invention. It is a schematic diagram for demonstrating the measuring method of the error which arises in the detected value of a current sensor. It is a graph which shows the measurement result of the error which arises in the detection value of a current sensor. It is a graph which shows the measurement result of the error which arises in the detection value of a current sensor. It is a graph which shows the measurement result of the error which arises in the detection value of a current sensor. It is a schematic diagram for demonstrating the correction value memorize | stored in the correction value table. It is a flowchart which shows the procedure of the process which the electric power supply apparatus which concerns on this invention performs. It is a flowchart which shows the procedure of the detection value correction | amendment process which the electric power supply apparatus which concerns on this invention performs.

Explanation of symbols

1 Alternator (generator)
2 Engine 3 Battery 4 Switch (stopping means)
5 Load 6 Current sensor 10 Control unit (stop determination means, pre-stop detection value acquisition means, correction value determination means, correction means, remaining capacity calculation means, remaining time calculation means, engine control signal acquisition means)
11 Storage section (correction value storage means, detection value storage means)
12 Correction value table 13 IG switch 14 Warning light (warning means)

Claims (5)

A generator for supplying the generated power to the load; a battery for storing the power generated by the generator; and a battery for supplying the stored power to the load; a charging current from the generator to the battery; and In a power supply device comprising a current sensor for detecting a discharge current to the load,
Stop determination means for determining stop of power supply of the generator;
A pre-stop detection value acquisition means for acquiring a detection value detected by the current sensor before the stop when the power supply of the generator is stopped;
Correction value storage means for storing a correction value for the detection value of the current sensor in association with the detection value before the power supply stop of the generator and the detection value after the stop;
After the power supply of the generator is stopped, the correction value stored by the correction value storage means according to the detection value before stop acquired by the detection value acquisition means before stop and the detection value detected by the current sensor Correction value determining means for determining a correction value to be used for correcting the detected value from:
A power supply apparatus comprising: correction means for correcting a detection value of the current sensor in accordance with a correction value determined by the correction value determination means after power supply to the generator is stopped. A remaining capacity calculating means for calculating a remaining capacity of power stored in the battery;
A remaining time calculating means for calculating a remaining time during which power can be supplied from the battery to the load according to the detected value corrected by the correcting means and the remaining capacity calculated by the remaining capacity calculating means;
The power supply apparatus according to claim 1, further comprising: a warning unit that issues a warning when the remaining time calculated by the remaining time calculating unit is shorter than a predetermined time. A remaining capacity calculating means for calculating a remaining capacity of power stored in the battery;
A remaining time calculating means for calculating a remaining time during which power can be supplied from the battery to the load according to the detected value corrected by the correcting means and the remaining capacity calculated by the remaining capacity calculating means;
The power supply device according to claim 1, further comprising: a stop unit that stops power supply from the battery to the load when the remaining time calculated by the remaining time calculation unit is shorter than a predetermined time. The current sensor is configured to detect current continuously or intermittently,
A detection value storage means for storing the detection value of the current sensor;
The detection value acquisition unit before stop acquires a detection value before stoppage of power supply from the detection value storage unit. The method according to any one of claims 1 to 3, wherein the detection value before stoppage of power supply is acquired. Power supply device. The generator is configured to generate electricity in accordance with the operation of the vehicle engine,
Engine control signal acquisition means for acquiring a control signal related to start / stop of the engine,
The stop determination unit is configured to determine whether to stop the power supply of the generator according to an operating state of the engine based on a control signal acquired by the engine control signal acquisition unit. The power supply device according to any one of claims 1 to 4.

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