JP2014054147A - Power supply controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply controller for vehicle, capable of achieving the maximum reduction effect of power consumption and performing switching operations between DC driving and PWM driving of a load at such timing that a user does not sense the switching operations.SOLUTION: The power supply controller for vehicle includes determination means 5 for determining whether or not detected voltage values of on-vehicle power supplies 1, B are higher than a threshold value and, when the determination means 5 is determined to be higher than the threshold value, PWM-controls voltages of the on-vehicle power supplies 1, B to a target voltage value lower than the threshold value and transmits the PWM-controlled voltage to a load, and further includes means 7, 8, 9 for detecting a power value consumed by the load and means 5, 5a for changing the threshold value to be low or high according to the magnitude of the power value detected by the detecting means 7, 8, 9.

Description

  The present invention determines whether or not the detected voltage value of the in-vehicle power supply is higher than a threshold value, and determines that the voltage of the in-vehicle power supply is lower than the threshold value by PWM (Pulse Width Modulation) control. In addition, the present invention relates to a vehicle power supply control device that applies a PWM-controlled voltage to a load.

Many devices (loads) mounted on a vehicle have a rating of around 12V, and the performance is optimally exhibited around 12V. However, since the output voltage value of the battery fluctuates depending on the charged amount, the output voltage value is higher than around 12V when the charged amount is relatively large. Further, the output voltage value of the alternator (on-vehicle generator) is set to more (13 to 16 V) in order to charge the battery.
Therefore, recently, from the viewpoint of energy saving (power saving) and prevention of shortening the life of equipment, a vehicle power supply control apparatus that supplies power to equipment by PWM control of the power supply voltage from the battery and the alternator is becoming widespread. is there.

  In such a vehicle power supply control device, detection and A / D (analog / digital) conversion are performed so that a sensitive duty ratio variation and oscillation phenomenon do not occur due to vehicle-specific power supply voltage fluctuation, voltage fluctuation due to PWM frequency, and the like. A digital filter process is applied to the measured voltage value. As the digital filter, an IIR (infinite impulse response) filter, an FIR (finite impulse response) filter, or the like is used.

When a digital filter process is performed with an IIR filter on the detected and A / D converted voltage value, an arithmetic process is performed according to equation (1).
(1-α) × (Voltage value output one cycle before)
+ Α × (detected voltage value) = voltage value (where 1 ≧ α> 0) (1)

  FIG. 9 shows a voltage value (filter applied voltage) calculated and output with a start voltage of 10.0 V and a sampling period of 10 ms according to the expression (1) when the voltage at the positive terminal + B of the battery rises from 0 V to 16 V. FIG. Here, the coefficient α in the equation (1) is 0.05, and the response delay until the filter applied voltage reaches from 10 V to 13.2 V (starting voltage value) and the PWM control of the voltage at the plus terminal + B is started. Is 150 ms.

  Japanese Patent Application Laid-Open No. 2004-228688 includes a voltage detection unit that detects an output voltage value of a battery, and uses a duty ratio based on the output voltage value detected by the voltage detection unit to perform PWM control of power supplied to the load by the battery. An apparatus is disclosed. The voltage detection means periodically detects the output voltage value of the battery, and an IIR with a circuit constant determined so as to suppress a pulsation component having a frequency of 20 Hz or more included in the output voltage value of the battery to 1 / √2 or less. An (Infinite Impulse Response) filter is provided, and the duty ratio is determined based on the output voltage value filtered by the IIR filter.

  Patent Document 2 discloses a PWM that generates a pulse signal whose duty cycle changes in response to rising / falling of a timing signal for turning on / off, imitating rising / falling of light emission in turning on / off of a filament. A lighting / extinguishing control device having a signal generation unit and a light emission control unit that controls the light emission unit in response to a pulse signal of the PWM signal generation unit is disclosed. This lighting / extinguishing control device also has a storage unit for storing a control data table for duty cycle control by the PWM signal generation unit.

  The control data table includes a rise table that is referred to at the rise of light emission and a fall table that is referred to at the fall of light emission. The rise table and the fall table are respectively the rise / rise of the timing signal. The elapsed time from the fall is associated with the duty cycle of the pulse signal. Further, the relationship between the two tables cannot be superimposed on each other.

JP 2010-172176 A WO2009 / 019945

Since the above-described vehicle power supply control device uses a digital filter, there is a problem that a response delay occurs in PWM control due to the time constant of the digital filter when the power supply voltage fluctuates.
For example, as shown in FIG. 10, when the power supply voltage rises, the voltage after applying the digital filter is delayed in rising, and as a result, the start of PWM control is delayed, and the effective voltage subjected to PWM control becomes The target voltage for PWM control is temporarily exceeded. As a result, the effect of reducing power consumption (power saving effect) is reduced and the performance of the load is improved. However, the user may perceive flicker in the case of a lamp.

Also, as shown in FIG. 10, when the power supply voltage falls during execution of PWM control, the voltage after applying the digital filter is delayed in dropping, and as a result, the stop of PWM control is delayed. Therefore, the effective voltage subjected to the PWM control temporarily falls below the target voltage of the PWM control. As a result, the power consumption reduction effect (power saving effect) is increased, but the load performance is reduced, and the user may perceive flicker in the case of a lamp.
Accordingly, the response delay caused by the time constant of the digital filter causes a delay in switching between the DC drive and the PWM drive of the load, the effect of reducing the power consumption becomes unstable, and the switching between the DC drive and the PWM drive of the load becomes unstable. The problem is that it is perceived by the user.

  The present invention has been made in view of the circumstances as described above, and has a maximum effect of reducing power consumption, and power control for a vehicle that can perform switching between load DC driving and PWM driving at a timing that is not perceived by the user. An object is to provide an apparatus.

  The vehicular power supply control device according to the first aspect of the present invention comprises determination means for determining whether or not the detected voltage value of the in-vehicle power supply is higher than a threshold value, and when the determination means determines that the voltage value is higher than the threshold value, In the vehicle power supply control device that applies PWM control to a target voltage value lower than the threshold value and applies the PWM controlled voltage to the load, means for detecting the power value consumed by the load, and the power value detected by the means And a means for changing the threshold value to be lower / higher according to the size.

  In this vehicle power supply control device, it is determined whether or not the detected voltage value of the in-vehicle power supply is higher than a threshold value, and when it is determined that the detected voltage value is higher than the threshold value, the voltage of the in-vehicle power supply is PWM controlled to a target voltage value lower than the threshold value. The PWM controlled voltage is applied to the load. The power value consumed by the load is detected, and the threshold value is changed to be lower / higher according to the magnitude of the detected power value.

  The vehicle power supply control device according to the second aspect of the present invention is an arithmetic processing means for performing a calculation process on the voltage value of the in-vehicle power supply detected at a predetermined sampling period, and outputting a voltage value in which fluctuations in the voltage value are slowed down; Determination means for determining whether or not the voltage value output by the arithmetic processing means is higher than a threshold value, and when the determination means determines that the voltage value is higher than the threshold value, the voltage of the in-vehicle power supply is set to a target voltage lower than the threshold value. In the vehicle power supply control device that performs PWM control on the value and applies the PWM controlled voltage to the load, the means for detecting the power value consumed by the load, and depending on the magnitude of the power value detected by the means, And means for changing the threshold value to be low / high.

  In this vehicle power supply control device, the arithmetic processing means performs an arithmetic process on the voltage value of the in-vehicle power supply detected at a predetermined sampling period, and outputs a voltage value in which the fluctuation is moderated. The determination means determines whether or not the output voltage value is higher than the threshold value, and when the determination means determines that the voltage value is higher than the threshold value, the voltage of the on-vehicle power supply is PWM controlled to a target voltage value lower than the threshold value, and PWM control is performed. Applied voltage to the load. The power value consumed by the load is detected, and the threshold value is changed to be lower / higher according to the magnitude of the detected power value.

  The vehicle power supply control device according to the third invention is based on the voltage value of the in-vehicle power supply detected at a predetermined sampling period, (1-α) × (voltage value output one period before) + α × (detected voltage value) ) = Voltage value (where 1 ≧ α> 0), a calculation processing unit that outputs the calculated voltage value, and a determination unit that determines whether the voltage value output by the calculation processing unit is higher than a threshold value When the determination means determines that the voltage is higher than a threshold, the vehicle power supply voltage is PWM-controlled to a target voltage value lower than the threshold, and the PWM-controlled voltage is supplied to the load. Power detection means for detecting a power value consumed by the load; storage means for storing a threshold value set to low / high according to the magnitude of the power value to be detected by the power detection means; Threshold value corresponding to the power value detected by the power detection means Is read out from the storage means, and the determination means makes a determination based on a threshold value read by the means.

  In this vehicle power supply control device, based on the voltage value of the in-vehicle power supply detected at a predetermined sampling cycle, the arithmetic processing means calculates (1−α) × (voltage value output one cycle before) + α × (detected voltage Value) = voltage value (where 1 ≧ α> 0), and the calculated voltage value is output. The determination means determines whether or not the output voltage value is higher than the threshold value, and when the determination means determines that the voltage value is higher than the threshold value, the voltage of the on-vehicle power supply is PWM controlled to a target voltage value lower than the threshold value, and PWM control is performed. Applied voltage to the load. The power detection means detects the power value consumed by the load, and the storage means stores a threshold value determined as low / high according to the magnitude of the power value to be detected. The reading unit reads a threshold value corresponding to the power value detected by the power detection unit from the storage unit, and the determination unit determines based on the read threshold value.

  According to the vehicle power supply control device of the present invention, it is possible to achieve a vehicle power supply control device that maximizes the effect of reducing power consumption and can perform switching between load DC drive and PWM drive at a timing that is not perceived by the user. Can do.

1 is a block diagram showing a schematic configuration of an embodiment of a vehicle power supply control device according to the present invention. It is a flowchart which shows operation | movement of embodiment of the vehicle power supply control apparatus which concerns on this invention. It is a flowchart which shows operation | movement of embodiment of the vehicle power supply control apparatus which concerns on this invention. It is a wave form diagram which shows the example of the voltage value which the filter calculating means performed and performed the filter calculation process, when the voltage of the positive terminal of a battery rose. 1 is a block diagram showing a schematic configuration of an embodiment of a vehicle power supply control device according to the present invention. It is a flowchart which shows operation | movement of embodiment of the vehicle power supply control apparatus which concerns on this invention. 1 is a block diagram showing a schematic configuration of an embodiment of a vehicle power supply control device according to the present invention. It is a flowchart which shows operation | movement of embodiment of the vehicle power supply control apparatus which concerns on this invention. It is a wave form diagram which shows the example of the voltage value which the filter calculating means performed and performed the filter calculation process, when the voltage of the positive terminal of a battery rose. It is a wave form diagram which shows the example of the voltage value which the conventional filter calculating means performed the filter calculation process and output, when the voltage of the plus terminal of a battery rose.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of a vehicle power supply control device according to the present invention.
In this vehicle power supply control device, electric power generated and rectified by an alternator (on-vehicle generator, AC generator) 1 is charged to a battery B, and a load which is a lamp through each switching circuit 10, 11, 12. Power is supplied to 13,14,15. When the battery B is not charged, the discharged power from the battery B is supplied to the loads 13, 14, and 15 through the switching circuits 10, 11, and 12.

  The power supply voltage values output from the alternator 1 and the battery B are detected by the voltage measuring means 3 through the power supply input circuit (filter) 2, A / D converted, and output. The power supply voltage value A / D converted and output by the voltage measuring means 3 is read by the filter calculating means (arithmetic processing means) 4 at a predetermined sampling period. It is assumed that the sampling cycle read by the filter calculation unit 4 is set to be the same as the sampling cycle in which the voltage measurement unit 3 performs A / D conversion.

The filter calculation means 4 performs digital filter processing on the read power supply voltage value with an IIR filter. This digital filter processing is performed by calculating equation (1).
(1-α) × (Voltage value output one cycle before)
+ Α × (detected voltage value) = voltage value (where 1 ≧ α> 0) (1)

The power supply voltage value subjected to the digital filter processing according to the equation (1) is given to the duty ratio calculation means 5. The duty ratio calculation means 5 uses the given power supply voltage value and a predetermined voltage value (target voltage value), and formula (2) (predetermined voltage value / power supply voltage value) ² × 100 (%) (2)
Thus, the duty ratio is calculated for each of the loads 13, 14, and 15 and given to the duty ratio output means 6.

The duty ratio output means 6 performs PWM control of the switching circuits 10, 11, and 12 according to the given duty ratio, and the power supply voltage subjected to PWM control is supplied to the loads 13, 14, and 15, respectively. In the switching circuits 10, 11, and 12, when DC power is applied to the loads 13, 14, and 15 and PWM control is not performed, the power supply-loads 13, 14, and 15 are maintained in an on (connected) state.
The output monitoring circuit (power detection means) 7 converts the voltage value and current value (effective value) of power PWM-controlled by the switching circuits 10, 11, and 12 into voltage values, respectively, and voltage / current measurement means (power detection) Means).

The voltage / current measuring means 8 performs A / D conversion on the voltage value and the current value which are given after being converted into voltage values, and gives them to a W (watt) number calculation means (power detection means) 9.
The W number calculation means 9 multiplies the voltage value and the current value supplied to the given loads 13, 14, and 15 to calculate the power consumption values of the loads 13, 14, and 15, respectively. The power consumption value is given to the duty ratio calculation means 5.

The duty ratio calculating means 5 stores a power supply voltage value (threshold value, PWM control start voltage value) at which PWM control is to be started, corresponding to the power consumption values to be detected by the loads 13, 14, and 15. (Storage means) 5a is incorporated. The PWM control start voltage value is determined to be low / high depending on the power consumption value.
The PWM control start voltage value corresponds to each power consumption value of the loads 13, 14, 15, and the maximum reduction effect (power saving effect) of the assumed power consumption is obtained. It is determined on the basis of actual measurement or calculation so that the switching of the PWM drive can be executed at a timing at which the user does not sense (feels no flicker or the like).

The table 5a includes, for example, the PWM control start voltage value corresponding to the power consumption value W, VD corresponding to W ≧ WC, VC corresponding to WC> W ≧ WB, VB corresponding to WB> W ≧ WA, WA> VA corresponding to W (where WC>WB> WA, VD <VC <VB <VA).
The duty ratio calculation means (reading means) 5 reads the PWM control start voltage value corresponding to each power consumption value of the given loads 13, 14, 15 from the table 5a. The duty ratio calculation means (determination means) 5 determines whether or not the power supply voltage value given from the filter calculation means 4 is higher than the read PWM control start voltage value for each of the loads 13, 14, and 15. Equation (2) is calculated for the loads 13, 14, and 15 determined as follows. The duty ratios of the loads 13, 14 and 15 calculated by the expression (2) are given to the duty ratio output means 6.

  The voltage measuring means 3, the filter calculating means 4, the duty ratio calculating means 5, the duty ratio output means 6, the voltage / current measuring means 8 and the W number calculating means 9 described above are constituted by a power supply control unit 22 provided with a microcomputer. The power supply control unit 22 is given a start / stop signal for each of the loads 13, 14 and 15 from the vehicle side.

The operation of the vehicular power supply control apparatus having such a configuration will be described below with reference to the flowcharts of FIGS. In this vehicle power supply control device, the loads 13, 14, and 15 operate in the same manner in parallel. Here, the load 13 will be described.
When the power supply control unit 22 is given a start signal, first, the duty ratio calculation unit 5 sets an initial value to the PWM control start voltage value Vs (S1), and then the W number calculation unit 9 performs voltage / current measurement. The voltage value and current value detected for the load 13 are read from the means 8 (S3). Next, the W number calculation means 9 multiplies the read voltage value and current value to calculate the power consumption value (W number) of the load 13 and gives it to the duty ratio calculation means 5 (S5).

The duty ratio calculation means 5 determines whether or not the given W number is greater than or equal to WA (for example, 5 W (Watt)) (S7). If not greater than WA, the PWM control start voltage value Vs is set to VA. After (S19), PWM control of the power supply voltage is executed (S15).
If the given W number is greater than or equal to WA (S7), the duty ratio calculating means 5 determines whether or not the W number is greater than or equal to WB (for example, 35 W (Watt)) (S9). For example, after the PWM control start voltage value Vs is set to VB (S21), the power supply voltage PWM control is executed (S15).

When the given W number is equal to or greater than WB (S9), the duty ratio calculating means 5 determines whether the W number is equal to or greater than WC (for example, 55 W (Watt)) (S11). For example, after setting the PWM control start voltage value Vs to VC (S23), the PWM control of the power supply voltage is executed (S15).
If the given W number is greater than or equal to WC (S11), the duty ratio calculation means 5 sets the PWM control start voltage value Vs to VD (S13), and then executes PWM control of the power supply voltage (S15). However, as described above, VD <VC <VB <VA.

When the duty ratio calculating means 5 executes PWM control of the power supply voltage (S15), first, the power supply voltage value Vr is read from the filter calculating means 4 (S25 in FIG. 3), and the power supply voltage value Vr is determined from the PWM control start voltage value Vs. It is determined whether it is larger (S27).
If the power supply voltage value Vr is not greater than the PWM control start voltage value Vs (S27), the duty ratio calculation means 5 returns as it is.

If the power supply voltage value Vr is larger than the PWM control start voltage value Vs (S27), the duty ratio calculation means 5 calculates the equation (2) using the power supply voltage value Vr and calculates the duty ratio D (S29). . Next, the calculated duty ratio D is output from the duty ratio output means 6 (S31), the switching circuit 10 is PWM-controlled, and the process returns.
When the power supply control unit 22 returns, it determines whether or not a stop signal (power supply off) is given (S17). If no stop signal is given, the W number calculation means 9 performs voltage / current measurement means. The voltage value and current value detected for the load 13 are read from 8 (S3).

The operation (S3-13, S19-23) for setting the PWM control start voltage value Vs based on the W number of power consumption of the load 13 does not need to be executed constantly, and the power consumption is stable when the load 13 is started. It is sufficient to execute only during the period until During other periods, if no stop signal is given (S17), PWM control of the power supply voltage is executed (S15). When the power consumption of the load 13 is variable, when the power consumption is changed, the PWM control start voltage value Vs is set based on the W number of the power consumption of the load 13 (S3 to 13, S19). ˜23) may be executed.
If the stop signal is given (S17), the power controller 22 ends.

  FIG. 4 shows that when the voltage of the positive terminal + B of the battery B rises from 0V to 16V, the filter calculation means 4 executes the filter calculation processing with the start voltage 10.0V and the sampling period 10 ms according to the equation (1). It is a wave form diagram which shows the voltage value (filter applied voltage) output in this way. Here, the coefficient α in the equation (1) is 0.05, and the PWM control start voltage value Vs of the duty ratio calculation means 5 is set to 12.0V.

After the filter application voltage rises from 10V, the duty ratio calculation means 5 determines that the filter application voltage is higher than 12.0V, and the response delay until the PWM control of the voltage at the plus terminal + B starts is 80 ms. It has become.
Since the PWM control start voltage value Vs is set to 13.2 V and the other conditions are the same as those in FIG. 4 in FIG. 9 described above, the response delay is 150 ms. Therefore, the PWM control start voltage value Vs is set to 13.2 V. It can be seen that the response delay is shortened from 150 ms to 80 ms by changing from 12.0V to 12.0V.

  According to the vehicle power supply control device according to the first embodiment, the PWM control does not cause sensitive duty ratio fluctuation and oscillation phenomenon, and the effect of reducing power consumption is maximized. It is possible to realize a vehicle power supply control device that can be executed at a timing when the switching is not sensed by the user (no flicker or the like is sensed).

(Embodiment 2)
FIG. 5 is a block diagram showing a schematic configuration of the second embodiment of the vehicle power supply control device according to the present invention.
In this vehicle power supply control device, electric power generated and rectified by an alternator (on-vehicle generator, AC generator) 1 is charged to a battery B, and a load which is a motor through each switching circuit 10, 11, 12. Power is supplied to 16, 17, and 18. When the battery B is not charged, the discharged power from the battery B is supplied to the loads 16, 17, and 18 through the switching circuits 10, 11, and 12.

  The power supply voltage value that has been subjected to the digital filter processing by the equation (1) in the filter calculating means 4 is given to the duty ratio calculating means 5. The duty ratio calculation means 5 calculates a duty ratio for each of the loads 16, 17, and 18 by using the given power supply voltage value and a predetermined voltage value (target voltage value) according to the equation (2), and outputs the duty ratio output means. Give to 6.

The duty ratio output means 6 performs PWM control of the switching circuits 10, 11, and 12 according to the given duty ratio, and the PWM-controlled power supply voltage is supplied to the loads 16, 17, and 18, respectively. In the switching circuits 10, 11, and 12, when DC power is applied to the loads 16, 17, and 18, and the PWM control is not performed, the power source-loads 16, 17, and 18 are maintained in an on (connected) state.
The output monitoring circuit (power detection means) 7 converts the voltage value and current value (effective value) of power PWM-controlled by the switching circuits 10, 11, and 12 into voltage values, respectively, and voltage / current measurement means (power detection) Means).

The voltage / current measuring means 8 performs A / D conversion on the voltage value and the current value which are given after being converted into voltage values, and gives them to a W (watt) number calculation means (power detection means) 9.
The W number calculation means 9 multiplies the voltage values and current values supplied to the given loads 16, 17, and 18 to calculate the power consumption values of the loads 16, 17, and 18, respectively. The power consumption value is given to the duty ratio calculation means 5.

The duty ratio calculating means 5 stores a power supply voltage value (threshold value, PWM control start voltage value) at which PWM control is to be started, corresponding to the power consumption values to be detected by the loads 16, 17, and 18. (Storage means) 5b is incorporated. The PWM control start voltage value is determined to be low / high depending on the power consumption value.
The PWM control start voltage value corresponds to each power consumption value of the loads 16, 17 and 18, and the maximum reduction effect (power saving effect) of the assumed power consumption is obtained. It is determined on the basis of actual measurement or calculation so that the switching of the PWM drive can be executed at a timing at which the user does not sense (no change in motor rotation sound or the like).

For example, the table 5b shows the PWM control start voltage value corresponding to the power consumption value W as VH corresponding to W ≧ WF, VG corresponding to WF> W ≧ WE, VF corresponding to WE> W ≧ WD, WD> VE corresponding to W (however, WF>WE> WD, VH <VG <VF <VE).
The duty ratio calculation means (reading means) 5 reads the PWM control start voltage value corresponding to each power consumption value of the given loads 16, 17, 18 from the table 5b.

  The duty ratio calculation means (determination means) 5 determines whether or not the power supply voltage value given from the filter calculation means 4 is higher than the read PWM control start voltage value for each of the loads 16, 17, and 18. Equation (2) is calculated for the determined loads 16, 17, and 18. The duty ratios of the loads 16, 17 and 18 calculated by the expression (2) are given to the duty ratio output means 6. Since the other configuration of the second embodiment is the same as the configuration of the first embodiment (FIG. 1) described above, the description thereof is omitted.

The operation of the vehicular power supply control apparatus having such a configuration will be described below with reference to the flowchart of FIG. In this vehicle power supply control device, the loads 16, 17, and 18 operate in the same manner in parallel. Here, the load 16 will be described.
When the power supply control unit 22 is given a start signal, first, the duty ratio calculation unit 5 sets an initial value to the PWM control start voltage value Vs (S33), and then the W number calculation unit 9 performs voltage / current measurement. The voltage value and current value detected for the load 16 are read from the means 8 (S35). Next, the W number calculation means 9 multiplies the read voltage value and current value to calculate the power consumption value (W number) of the load 16 and gives it to the duty ratio calculation means 5 (S37).

The duty ratio calculation means 5 determines whether or not the given W number is equal to or greater than WD (S39). If not greater than WD, the PWM control start voltage value Vs is set to VE (S51), and then the power supply voltage The PWM control is executed (S47).
The duty ratio calculating means 5 determines whether or not the given W number is equal to or greater than WD (S39), and determines whether or not the W number is equal to or greater than WE (S41). After setting Vs to VF (S53), PWM control of the power supply voltage is executed (S47).

The duty ratio calculating means 5 determines whether or not the given W number is equal to or greater than WE (S41), and determines whether or not the W number is equal to or greater than WF (S43). After setting Vs to VG (S55), PWM control of the power supply voltage is executed (S47).
If the given W number is equal to or greater than WF (S43), the duty ratio calculation means 5 sets the PWM control start voltage value Vs to VH (S45), and then executes PWM control of the power supply voltage (S47). However, as described above, VH <VG <VF <VE.

Since the operation (S47) in which the duty ratio calculation means 5 executes the PWM control of the power supply voltage is the same as the operation (FIG. 3) that executes the PWM control of the power supply voltage described in the first embodiment, the description is omitted. To do.
The power supply control unit 22 determines whether or not a stop signal (power off) is given after the duty ratio calculation means 5 executes PWM control of the power supply voltage (S47) (S49), and the stop signal is given. If not, the W number calculation means 9 reads the voltage value and current value detected for the load 16 from the voltage / current measurement means 8 (S35).

  Note that the operation (S35 to 45, S51 to 55) for setting the PWM control start voltage value Vs based on the W number of power consumption of the load 16 does not need to be performed constantly, and the power consumption is stable when the load 16 is started. It is sufficient to execute only during the period until During other periods, if the stop signal is not given (S49), the PWM control of the power supply voltage is executed (S47).

When the power consumption of the load 16 is variable, when the power consumption is changed, an operation for setting the PWM control start voltage value Vs based on the W number of the power consumption of the load 16 (S35 to 45, S51). ~ 55) may be executed.
The power supply control unit 22 ends if a stop signal is given (S49). The other operations in the second embodiment are the same as the operations in the first embodiment described above, and thus the description thereof is omitted.

  According to the vehicle power supply control device according to the second embodiment, the PWM control does not cause sensitive duty ratio fluctuation and oscillation phenomenon, and the effect of reducing power consumption is maximized. It is possible to realize a vehicular power supply control device that can be executed at a timing when the switching is not sensed by the user (a change in rotational sound is not sensed).

(Embodiment 3)
FIG. 7 is a block diagram showing a schematic configuration of the third embodiment of the vehicle power supply control device according to the present invention.
In this vehicle power supply control device, the electric power generated and rectified by the alternator (on-vehicle generator, AC generator) 1 is charged to the battery B, and the load serving as a heater is passed through each switching circuit 10, 11, 12. Power is supplied to 19, 20, and 21. When the battery B is not charged, the discharged power from the battery B is supplied to the loads 19, 20, and 21 through the switching circuits 10, 11, and 12.

  The power supply voltage value that has been subjected to the digital filter processing by the equation (1) in the filter calculating means 4 is given to the duty ratio calculating means 5. The duty ratio calculation means 5 calculates a duty ratio for each of the loads 19, 20, and 21 by using the given power supply voltage value and a predetermined voltage value (target voltage value) according to the equation (2), and outputs the duty ratio output means. Give to 6.

The duty ratio output means 6 performs PWM control of the switching circuits 10, 11, and 12 according to the given duty ratio, and the PWM-controlled power supply voltage is applied to the loads 19, 20, and 21, respectively. In the switching circuits 10, 11, and 12, when DC power is applied to the loads 19, 20, and 21, and the PWM control is not performed, the power source-loads 19, 20, and 21 are maintained in an on (connected) state.
The output monitoring circuit (power detection means) 7 converts the voltage value and current value (effective value) of power PWM-controlled by the switching circuits 10, 11, and 12 into voltage values, respectively, and voltage / current measurement means (power detection) Means).

The voltage / current measuring means 8 performs A / D conversion on the voltage value and the current value which are given after being converted into voltage values, and gives them to a W (watt) number calculation means (power detection means) 9.
The W number calculation means 9 calculates the power consumption value of each of the loads 19, 20, and 21 by multiplying the voltage values and current values supplied to the given loads 19, 20, and 21, respectively. The power consumption value is given to the duty ratio calculation means 5.

The duty ratio calculating means 5 stores a power supply voltage value (threshold value, PWM control start voltage value) at which PWM control is to be started, corresponding to the power consumption values to be detected by the loads 19, 20, and 21. (Storage means) 5c is incorporated. The PWM control start voltage value is determined to be low / high depending on the power consumption value.
The PWM control start voltage value corresponds to each power consumption value of the loads 19, 20, and 21, and an expected maximum power consumption reduction effect (power saving effect) is obtained. It is determined on the basis of actual measurement or calculation so that the switching of PWM drive can be executed at a timing when the user does not sense (for example, does not feel the fluctuation of the thawing speed of window freezing).

The table 5c shows, for example, the PWM control start voltage value corresponding to the power consumption value W as VL corresponding to W ≧ WI, VK corresponding to WI> W ≧ WH, VJ corresponding to WH> W ≧ WG, WG> VI corresponding to W is stored (where WI>WH> WG, VL <VK <VJ <VI).
The duty ratio calculation means (reading means) 5 reads the PWM control start voltage value corresponding to each power consumption value of the given loads 19, 20, 21 from the table 5c.

  The duty ratio calculation means (determination means) 5 determines whether or not the power supply voltage value given from the filter calculation means 4 is higher than the read PWM control start voltage value for each of the loads 19, 20, and 21. Equation (2) is calculated for the determined loads 19, 20, and 21. The duty ratios of the loads 19, 20 and 21 calculated by the expression (2) are given to the duty ratio output means 6. Since the other configuration of the third embodiment is the same as the configuration of the first embodiment (FIG. 1) described above, description thereof is omitted.

The operation of the vehicular power supply control apparatus having such a configuration will be described below with reference to the flowchart of FIG. In this vehicle power supply control device, the loads 19, 20, and 21 operate similarly in parallel, but the load 19 will be described here.
When the power supply control unit 22 is given a start signal, first, the duty ratio calculation unit 5 sets an initial value to the PWM control start voltage value Vs (S57), and then the W number calculation unit 9 performs voltage / current measurement. The voltage value and current value detected for the load 19 are read from the means 8 (S59). Next, the W number calculation means 9 multiplies the read voltage value and current value to calculate the power consumption value (W number) of the load 19 and gives it to the duty ratio calculation means 5 (S61).

The duty ratio calculation means 5 determines whether or not the given W number is equal to or greater than WG (S63). If not greater than WG, the PWM control start voltage value Vs is set to VI (S75), and then the power supply voltage The PWM control is executed (S71).
The duty ratio calculating means 5 determines whether or not the given W number is equal to or greater than WG (S63) and whether the W number is equal to or greater than WH (S65). After Vs is set to VJ (S77), PWM control of the power supply voltage is executed (S71).

The duty ratio calculating means 5 determines whether or not the W number is greater than or equal to WI if the given W number is greater than or equal to WH (S65). If not greater than WI, the PWM control start voltage value is determined. After Vs is set to VK (S79), power supply voltage PWM control is executed (S71).
If the given W number is greater than or equal to WI (S67), the duty ratio calculation means 5 sets the PWM control start voltage value Vs to VL (S69), and then executes PWM control of the power supply voltage (S71). However, as described above, VL <VK <VJ <VI.

Since the operation (S71) in which the duty ratio calculation means 5 executes the PWM control of the power supply voltage is the same as the operation (FIG. 3) that executes the PWM control of the power supply voltage described in the first embodiment, the description thereof is omitted. To do.
After the duty ratio calculation means 5 executes PWM control of the power supply voltage (S71), the power supply controller 22 determines whether or not a stop signal (power off) is given (S73), and the stop signal is given If not, the W number calculation means 9 reads the voltage value and current value detected for the load 16 from the voltage / current measurement means 8 (S59).

  Note that the operation (S59 to 69, S75 to 79) for setting the PWM control start voltage value Vs based on the power consumption W number of the load 19 does not need to be performed constantly, and the power consumption is stable when the load 19 is started. It is sufficient to execute only during the period until During other periods, if no stop signal is given (S73), PWM control of the power supply voltage is executed (S71).

Further, when the power consumption of the load 19 is variable, when the power consumption is changed, the PWM control start voltage value Vs is set based on the wattage of the power consumption of the load 19 (S59 to 69, S75). ~ 79) may be executed.
The power supply control unit 22 ends if a stop signal is given (S73). The other operations of the third embodiment are the same as the operations of the first embodiment described above, and thus description thereof is omitted.

  According to the vehicle power supply control device according to the third embodiment, the PWM control does not cause a sensitive duty ratio fluctuation and oscillation phenomenon, and the effect of reducing power consumption is maximized. It is possible to realize a vehicular power supply control device that can be executed at a timing when the switching is not perceived by the user (for example, the user does not feel a change in the thawing speed of window freezing).

1 Alternator (car power supply)
2 Power input circuit 3 Voltage measuring means 4 Filter computing means (arithmetic processing means)
5 Duty ratio calculation means (determination means, reading means)
5a, 5b, 5c Table (storage means)
6 Duty ratio output means 7 Output monitoring circuit (power detection means)
8 Voltage / current measurement means (power detection means)
9 W number calculation means (power detection means)
10, 11, 12 Switching circuit 13-21 Load 22 Power supply control part B Battery (vehicle power supply)

Claims (3)

A determination unit configured to determine whether or not the detected voltage value of the in-vehicle power source is higher than a threshold value, and when the determination unit determines that the voltage value is higher than the threshold value, the voltage of the in-vehicle power source is PWMed to a target voltage value lower than the threshold value; In a vehicle power supply control device for controlling and applying a PWM controlled voltage to a load,
The vehicle comprising: means for detecting a power value consumed by the load; and means for changing the threshold value to be lower / higher according to the magnitude of the power value detected by the means. Power control device. Arithmetic processing means for performing a calculation process on the voltage value of the in-vehicle power supply detected at a predetermined sampling period, and outputting a voltage value in which the fluctuation of the voltage value is slow, and the voltage value output by the arithmetic processing means is more than a threshold value Determination means for determining whether or not the voltage is higher, and when the determination means determines that the voltage is higher than a threshold value, the voltage of the in-vehicle power supply is PWM-controlled to a target voltage value lower than the threshold value, and the PWM-controlled voltage is loaded In the vehicle power supply control device given to
The vehicle comprising: means for detecting a power value consumed by the load; and means for changing the threshold value to be lower / higher according to the magnitude of the power value detected by the means. Power control device. Based on the voltage value of the in-vehicle power supply detected at a predetermined sampling cycle,
(1-α) × (Voltage value output one cycle before) + α × (Detected voltage value)
= Voltage value (however, 1 ≧ α> 0)
And processing means for outputting the calculated voltage value, and determination means for determining whether or not the voltage value output by the calculation processing means is higher than a threshold value, wherein the determination means is determined to be higher than the threshold value. In the vehicle power supply control device that performs PWM control of the voltage of the in-vehicle power supply to a target voltage value lower than the threshold, and applies the PWM-controlled voltage to the load,
Power detection means for detecting a power value consumed by the load; storage means for storing a threshold value set to low / high according to the magnitude of the power value to be detected by the power detection means; And a means for reading a threshold value corresponding to the power value detected by the power detection means from the storage means, wherein the determination means makes a determination based on the threshold value read by the means. Power supply control device.

Images