JP5874542B2 - Vehicle power supply control device - Google Patents

Description

  The present invention detects a voltage value from an in-vehicle power supply, calculates a duty ratio based on the detected power supply voltage value and a predetermined voltage value, and calculates a voltage from the in-vehicle power supply by PWM (Pulse Width Modulation) based on the calculated duty ratio. The present invention relates to a vehicle power supply control device that controls and applies a resistance load such as a heater and a defogger.

Many of the devices (loads) mounted on the vehicle have a rating of 12V according to the output voltage value of the in-vehicle battery, and the performance is optimally exhibited at 12V. However, since the output voltage value of the in-vehicle battery varies depending on the amount of stored electricity, the output voltage value is 12 V or more when the stored amount is relatively large. Further, the output voltage value of the alternator (on-vehicle generator) is set to 13 to 14 V or more in order to charge the on-vehicle battery.
Therefore, recently, from the viewpoints of energy saving (power saving) and prevention of shortening the life of equipment, a vehicle power supply control device for supplying power to equipment by controlling the power supply voltage from the onboard battery and the alternator to around 12V has become widespread. It's getting on.

  Patent Document 1 discloses a motor driver that drives a motor and outputs the actual current of the motor, an operation mode control unit that outputs a target current that is a target value of the current supplied to the motor, the actual current and the target current of the motor. And a feedback control unit that outputs a first duty ratio related to the drive frequency of the motor is disclosed. A spread spectrum modulation control unit that performs spread spectrum modulation on the driving frequency of the motor based on the first duty ratio, and outputs the second duty ratio, and absorbs the delay factor specific to the motor driver with the second duty ratio. And a duty correction calculation unit for correcting the third duty ratio.

Japanese Patent No. 4613071

In the vehicle power supply control device described above, the duty ratio of the PWM control is calculated by the formula (predetermined voltage value / power supply voltage value) ² × 100 using the power supply voltage value from the in-vehicle battery and the alternator and the predetermined voltage value. However, the duty ratio of the voltage applied to the device is not as expected due to the influence of the error of the entire device and the noise superimposed on the power supply voltage. Therefore, there is a problem that the voltage applied to the device drops, and it is impossible to achieve both reduction in power consumption (power saving effect) and optimum control of device performance. Further, when the device is a resistive load, there is room for further pursuit of either the power saving effect or the optimum control of the device performance depending on the power consumption.

  The present invention has been made in view of the circumstances as described above, and the duty ratio of the voltage applied to the resistive load is hardly affected by errors and noises of the entire apparatus, reducing power consumption, and resistive load. An object is to provide a vehicle power supply control device that can achieve both optimal control of performance and can further pursue either power saving effect or optimal control of device performance according to the power consumption of a resistive load. And

According to a first aspect of the present invention, there is provided a vehicular power supply control device that detects a voltage value of a vehicle-mounted power supply, a duty ratio calculation unit that calculates a duty ratio based on the power supply voltage value detected by the means and a predetermined voltage value, A vehicle power supply control device including a PWM control circuit that PWM-controls a voltage from the in-vehicle power source and applies the voltage to the resistance load based on the duty ratio calculated by the ratio calculation means, and detects a duty ratio of the voltage applied to the resistance load Means for comparing the duty ratio detected by the means and the duty ratio calculated by the duty ratio calculation means, and when the rated power of the resistance load is smaller than a predetermined value, as the average value of the given voltage is the higher than the predetermined voltage value, and when the rated power of the resistive load is larger than a predetermined value, the As the average value of the voltage applied to the anti-load is lower than the predetermined voltage value, based on the comparison result of the comparing means, and characterized in that it comprises a means for correcting the duty ratio in which the PWM control circuit controls To do.

In this vehicle power supply control device, the voltage value of the in-vehicle power supply is detected, the duty ratio calculation means calculates the duty ratio based on the detected power supply voltage value and the predetermined voltage value, and the PWM control circuit uses the calculated duty ratio to PWM control of the voltage from the in-vehicle power supply is applied to the resistance load. The comparison means detects the duty ratio of the voltage applied to the resistance load, and compares the detected duty ratio and the duty ratio calculated by the duty ratio calculation means. When the rated power of the resistive load is smaller than the predetermined value, the average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and the rated power of the resistive load is larger than the predetermined value In addition, the duty ratio controlled by the PWM control circuit is corrected based on the comparison result of the comparison means so that the average value of the voltage applied to the resistance load is lower than the predetermined voltage value .

As a result, the duty ratio of the voltage applied to the resistive load is hardly affected by errors and noises of the entire apparatus, and both power consumption reduction and optimal control of the resistive load performance can be achieved.
Moreover, a voltage higher than a predetermined voltage value is given to a resistive load with relatively low power consumption, and the power saving effect is reduced. However, since the power consumption of the resistive load itself is small, the power saving effect of the entire vehicle is reduced. The load performance is good, for example, the influence is small and the melting time of window freezing is shortened.
A resistive load with relatively large power consumption is given a voltage lower than a predetermined voltage value, and the power consumption of the resistive load itself is large, so the power saving effect of the vehicle as a whole is good, and the vehicle as a whole is affected. The load performance (for example, the thermal performance of the heater) can be ensured so as not to occur.

According to a second aspect of the present invention, there is provided a vehicle power supply control device comprising: means for detecting a power supply voltage value V of a vehicle-mounted power supply; duty ratio calculating means for calculating a duty ratio (predetermined voltage value / V) ² × 100; In a vehicle power supply control device comprising a PWM control circuit for PWM-controlling the voltage of the voltage to the resistance load, means for detecting a duty ratio of the voltage applied to the resistance load, the duty ratio detected by the means, and the Comparing means for comparing the duty ratio calculated by the duty ratio calculating means, and when the rated power of the resistive load is smaller than a predetermined value, the average value of the voltage applied to the resistive load is higher than the predetermined voltage value. as also in the case the rated power of the resistive load is larger than a predetermined value, so that the average value of the voltage applied to the resistive load is low than the predetermined voltage value becomes Based on the comparison result of the comparing means, characterized in that it comprises a means for changing the predetermined voltage value, wherein the duty ratio calculating means is used.

In this vehicle power supply control device, the duty ratio calculation means calculates the duty ratio (predetermined voltage value / V) ² × 100 from the detected power supply voltage value V of the in-vehicle power supply, and the PWM control circuit based on the calculated duty ratio However, the voltage from the in-vehicle power supply is PWM-controlled and applied to the resistance load. The comparison means detects the duty ratio of the voltage applied to the resistance load, and compares the detected duty ratio and the duty ratio calculated by the duty ratio calculation means. When the rated power of the resistive load is smaller than the predetermined value, the average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and the rated power of the resistive load is larger than the predetermined value In addition, the predetermined voltage value used by the duty ratio calculation means is changed based on the comparison result of the comparison means so that the average value of the voltage applied to the resistance load is lower than the predetermined voltage value.
Thereby, there can exist an effect | action and effect similar to the effect | action and effect of the vehicle power supply control apparatus which concern on the 1st invention mentioned above.

According to a third aspect of the present invention, there is provided a vehicle power supply control device comprising: means for detecting a power supply voltage value V of a vehicle-mounted power supply; duty ratio calculating means for calculating a duty ratio (predetermined voltage value / V) ² × 100; In a vehicle power supply control device comprising a PWM control circuit for PWM-controlling the voltage of the voltage to the resistance load, means for detecting a duty ratio of the voltage applied to the resistance load, the duty ratio detected by the means, and the Comparing means for comparing the duty ratio calculated by the duty ratio calculating means, and when the rated power of the resistive load is smaller than a predetermined value, the average value of the voltage applied to the resistive load is higher than the predetermined voltage value. as also in the case the rated power of the resistive load is larger than a predetermined value, so that the average value of the voltage applied to the resistive load is low than the predetermined voltage value becomes Based on the comparison result of the comparing means, characterized in that it comprises a means for changing the power supply voltage value V which the duty ratio calculating means is used.

In this vehicle power supply control device, the duty ratio calculation means calculates the duty ratio (predetermined voltage value / V) ² × 100 from the detected power supply voltage value V of the in-vehicle power supply, and the PWM control circuit based on the calculated duty ratio However, the voltage from the in-vehicle power supply is PWM-controlled and applied to the resistance load. The comparison means detects the duty ratio of the voltage applied to the resistance load, and compares the detected duty ratio and the duty ratio calculated by the duty ratio calculation means. When the rated power of the resistive load is smaller than the predetermined value, the average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and the rated power of the resistive load is larger than the predetermined value In addition, the power supply voltage value V used by the duty ratio calculation means is changed based on the comparison result of the comparison means so that the average value of the voltage applied to the resistance load is lower than the predetermined voltage value .
Thereby, there can exist an effect | action and effect similar to the effect | action and effect of the vehicle power supply control apparatus which concern on the 1st invention mentioned above.

According to a fourth aspect of the present invention, there is provided a vehicular power supply control device that detects a voltage value of a vehicle-mounted power supply through a filter circuit, and uses the power supply voltage value V detected by the means to make a duty ratio (predetermined voltage value / V) ² × In a vehicle power supply control device comprising a duty ratio calculating means for calculating 100 and a PWM control circuit for PWM-controlling the voltage of the in-vehicle power supply and applying the voltage to the resistance load, the duty ratio of the voltage applied to the resistance load is detected And a comparison means for comparing the duty ratio detected by the means and the duty ratio calculated by the duty ratio calculation means, and when the rated power of the resistance load is smaller than a predetermined value, the resistance load is applied to the resistance load. as the average value of the voltage that is becomes the high than the predetermined voltage value, and when the rated power of the resistive load is larger than a predetermined value, applied to the resistive load So that the average value of the voltage becomes lower than the predetermined voltage value, based on the comparison result of the comparing means, characterized in that it comprises a means for changing the time constant of the filter circuit.

In this vehicle power supply control device, the voltage value of the in-vehicle power supply is detected through a filter circuit, and the duty ratio calculation means uses the detected power supply voltage value V to calculate the duty ratio (predetermined voltage value / V) ² × 100. Calculate and apply the voltage of the on-vehicle power supply to the resistance load by PWM control. The comparison means detects the duty ratio of the voltage applied to the resistance load, and compares the detected duty ratio and the duty ratio calculated by the duty ratio calculation means. When the rated power of the resistive load is smaller than the predetermined value, the average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and the rated power of the resistive load is larger than the predetermined value In addition, the time constant of the filter circuit is changed based on the comparison result of the comparison means so that the average value of the voltage applied to the resistance load is lower than the predetermined voltage value .
Thereby, there can exist an effect | action and effect similar to the effect | action and effect of the vehicle power supply control apparatus which concern on the 1st invention mentioned above.

According to a fifth aspect of the present invention, there is provided a vehicular power supply control device that detects a voltage value of a vehicle-mounted power supply, a duty ratio calculation unit that calculates a duty ratio based on the power supply voltage value detected by the means and a predetermined voltage value, In a vehicular power supply control device comprising a switching circuit that PWM-controls the voltage of the in-vehicle power source and applies it to the resistive load according to the duty ratio calculated by the duty ratio calculating means, the voltage applied to the resistive load is that of the switching circuit A rise time detecting means for detecting a rise time rising from an on time to a first voltage value based on the power supply voltage value; and a second voltage value based on the power supply voltage value from the off time of the switching circuit. until the fall time detecting means for detecting the fall of the fall time, if the rated power of the resistive load is less than a predetermined value, When the serial voltage rises up to a first voltage value, the early kuna so that from the turn-on time, and if the rated power of the resistive load is larger than a predetermined value, the voltage until a first voltage value Based on the rise time detected by the rise time detection means, the means for changing the turn-on time of the switching circuit and the rated power of the resistive load from a predetermined value so that the rise time is later than the turn-on time when a small, point the voltage falls to a second voltage value, the slow kuna so that from the off-time, and when the rated power of the resistive load is larger than a predetermined value, said voltage this provided but falls time until the second voltage value, so earlier than the off-time, based on the fall time of the fall time detecting means detects, and means for the switching circuit changes the time to turn off The features.

In this vehicle power supply control device, the voltage value of the in-vehicle power supply is detected, the duty ratio calculating means calculates the duty ratio based on the detected power supply voltage value and the predetermined voltage value, and the switching circuit is calculated based on the calculated duty ratio. The voltage of the in-vehicle power supply is PWM controlled and applied to the resistance load. The rise time detecting means detects the rise time when the voltage applied to the resistive load rises from the switching circuit ON time to the first voltage value based on the power supply voltage value, and is applied to the resistive load from the OFF time of the switching circuit. The fall time detecting means detects the fall time when the applied voltage falls to the second voltage value based on the power supply voltage value. If the rated power of the resistive load is less than the predetermined value, the voltage applied to the resistor load point rises up to the first voltage value, the early kuna so that than the ON time of the switching circuit, also, the resistive load When the rated power is greater than a predetermined value, the rise time detected by the rise time detection means is such that the time when the voltage applied to the resistance load rises to the first voltage value is later than the time when the switching circuit is turned on. Based on this, the time when the switching circuit is turned on is changed.

If the rated power of the resistive load is less than the predetermined value, the voltage applied to the resistor load falls time until the second voltage value is, the retarded kuna so that than the off time of the switching circuit, also, the resistive load Falling time detected by the fall time detecting means so that the time when the voltage applied to the resistance load falls to the second voltage value is earlier than the OFF time of the switching circuit when the rated power is larger than a predetermined value. The time when the switching circuit is turned off is changed based on the time.
Thereby, there can exist an effect | action and effect similar to the effect | action and effect of the vehicle power supply control apparatus which concern on the 1st invention mentioned above.

In the vehicular power supply control device according to a sixth aspect of the present invention, the duty ratio calculating means uses an arithmetic expression using the power supply voltage value and a predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100, A feature is that the duty ratio is calculated.

In this vehicular power supply control device, the duty ratio calculation means calculates the duty ratio using an arithmetic expression using the power supply voltage value and the predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100.

In the vehicular power supply control device according to a seventh aspect of the present invention, the duty ratio calculating means uses a calculation formula that uses the power supply voltage value and a predetermined voltage value, and a first order approximate expression of (predetermined voltage value / power supply voltage value) ² × 100. Is used to calculate the duty ratio.

In this vehicle power supply control device, the duty ratio calculation means includes a power supply voltage value and a calculation formula using a predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100 first-order approximation formula, a The duty ratio is calculated using x (power supply voltage value) + b (a and b are arbitrary real numbers).

In the vehicular power supply control device according to an eighth aspect of the present invention, the duty ratio calculating means includes a calculation formula using the power supply voltage value and a predetermined voltage value, and a (predetermined voltage value / power supply voltage value) ² × 100 broken line approximation formula. It is configured to use and calculate the duty ratio.

In this vehicular power supply control device, the duty ratio calculation means includes a power supply voltage value and a calculation formula using a predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100, a polygonal line approximation formula obtained in advance, a × The duty ratio is calculated using (power supply voltage value) + b (a and b are real numbers determined for each predetermined section of the power supply voltage value).

According to a ninth aspect of the present invention, there is provided the vehicular power supply control apparatus, wherein the duty ratio calculating means is an arithmetic expression using the power supply voltage value and the predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100 quadratic polynomial approximation. Is used to calculate the duty ratio.

In this vehicle power supply control device, the duty ratio calculation means includes a power supply voltage value and a formula using a predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100 second-order polynomial approximation, a The duty ratio is calculated using × (power supply voltage value) ² + b × (power supply voltage value) + c (a, b, and c are arbitrary real numbers).

A vehicle power supply control device according to a tenth invention includes a plurality of any one of the vehicle power supply control devices according to the first to ninth inventions, and the plurality of vehicle power supply control devices each have a resistance load having a different rated power . It is characterized by being configured to PWM control the voltage to the.

This vehicle power supply control device includes a plurality of any one of the vehicle power supply control devices according to the first to ninth inventions, and each of the plurality of vehicle power supply control devices has a voltage applied to a resistive load having different rated power. Is configured to be PWM controlled. Thereby, according to the power consumption for every resistance load, reduction of power consumption and optimal control of apparatus performance can be made compatible.

According to the vehicle power supply control device according to the present invention, the duty ratio of the voltage applied to the resistance load is hardly affected by the error and noise of the entire device, thereby reducing the power consumption and the resistance load performance. Optimal control can be achieved at the same time.
Moreover, a voltage higher than a predetermined voltage value is given to a resistive load with relatively low power consumption, and the power saving effect is reduced. However, since the power consumption of the resistive load itself is small, the power saving effect of the entire vehicle is reduced. The load performance is good, for example, the influence is small and the melting time of window freezing is shortened.

  A resistive load with relatively large power consumption is given a voltage lower than a predetermined voltage value, and the power consumption of the resistive load itself is large. The load performance (for example, the thermal performance of the heater) can be ensured so as not to occur.

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 graph which shows the example of the primary approximation formula of the type | formula which calculates a duty ratio. It is a graph which shows the example of the broken line approximation formula of the type | formula which calculates a duty ratio. It is a graph which shows the example of the quadratic polynomial approximation of the type | formula which calculates a duty ratio. 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 graph which shows the example of the primary approximation formula of the type | formula which calculates a duty ratio. It is a graph which shows the example of the broken line approximation formula of the type | formula which calculates a duty ratio. It is a graph which shows the example of the quadratic polynomial approximation of the type | formula which calculates a duty ratio. 1 is a block diagram showing a schematic configuration of an embodiment of a vehicle power supply control device according to the present 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. 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 wave form diagram for demonstrating operation | movement of embodiment of the vehicle power supply control apparatus which concerns on this invention.

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, alternating current generator) 1 is charged to a battery 2 and through switching elements (PWM control circuits) S1, S2, S3. Power is supplied to the resistance loads L1, L2, and L3. When the battery 2 is not charged, the discharged power from the battery 2 is supplied to the resistive loads L1, L2, and L3 through the switching elements S1, S2, and S3.

The power supply voltage values output from the alternator 1 and the battery 2 are detected by a voltage detection unit (means for detecting a voltage value) 4 through a power supply input circuit 3, A / D converted, and provided to a duty ratio calculation means 5.
The duty ratio calculation means 5 uses a given power supply voltage value and a predetermined voltage value (here, 12.0 V), a theoretical formula (exact formula),
(12.0 / Power supply voltage value) ² x 100 (%) (1)
Thus, the duty ratio is calculated and given to the duty output unit (PWM control circuit) 9.

In order to reduce the amount of calculation, the duty ratio calculation means 5 replaces the exact expression (1) with a linear approximation expression or a linear approximation expression of the exact expression (1) obtained in advance by the least square method or the like. It is also possible to calculate the duty ratio and give it to the duty output unit 9 by quadratic polynomial approximation.
First order approximate expression of exact expression (1) a × (power supply voltage value) + b (%) (2)
(A and b are arbitrary real numbers)
Thus, when calculating the duty ratio y, the equation (2) becomes, for example, y = −8.976x + 201.4, and the graph is as shown in FIG. For comparison, the exact formula (1) is also shown in a graph.

Broken line approximation formula of exact formula (1) a × (power supply voltage value) + b (%) (3)
(A and b are arbitrary real numbers determined for each predetermined voltage section)
Thus, when calculating the duty ratio, equation (3) becomes a broken line in which coefficients a and b are determined for every 0.1 V, for example, as shown in FIG. For comparison, the exact formula (1) is also shown in a graph.

Quadratic polynomial approximation of exact expression (1) a × (power supply voltage value) ² + b × (power supply voltage value) + c (%) (4)
(A, b, and c are arbitrary real numbers)
Thus, when the duty ratio y is calculated, the equation (4) is, for example, y = 0.90662x ² −36.162x + 402.49, which is graphed as shown in FIG. For comparison, the exact formula (1) is also shown in a graph.

  The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 according to the given duty ratio, and the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3. Here, when the correction value A given from the duty ratio correction means 7 is not 0, the duty output unit 9 corrects the given duty ratio with the correction value A, and the switching element S1, PWM control is performed on S2 and S3.

  The duty ratio detection unit (means for detecting the duty ratio) 10 includes a voltage change of the power supply voltage PWM-controlled by the switching elements S1, S2, and S3 (change point of a high and low relationship with a predetermined threshold) and The time is detected and given to the duty ratio calculation unit (means for detecting the duty ratio) 11. In addition, although the voltage change of a power supply voltage and the time between the voltage changes may differ for every switching element S1, S2, and S3, the intermediate group or average value is calculated | required and used here.

The duty ratio calculation unit 11 calculates the duty ratio of the power supply voltage subjected to PWM control based on the voltage change detected by the duty ratio detection unit 10 and the time between the voltage changes, and the duty ratio comparison unit (comparison unit) 6 give.
The duty ratio comparison unit 6 compares the duty ratio calculated by the duty ratio calculation unit 11 and the duty ratio given from the duty ratio calculation unit 5, and corrects the comparison result (difference or ratio) by the duty ratio correction unit (corrects). (Means) 7

Based on the given comparison result, the duty ratio correction means 7 refers to the table stored in the table storage means 8 and obtains a correction value A for adding to or subtracting from the duty ratio calculated by the duty ratio calculation means 5. The correction value A is given to the duty output unit 9.
The duty output unit 9 corrects the given correction value A by adding (subtracting) it to the duty ratio given from the duty ratio calculating means 5, and PWMs the switching elements S1, S2, S3 by the corrected duty ratio. Control.

The table stored in the table storage means 8 is measured by associating the correction value A for correcting the duty ratio calculated by the duty ratio calculation means 5 with the comparison result (difference or ratio) of the duty ratio comparison means 6. Alternatively, it is calculated and stored based on the calculation.
When the reference current consumption (rated current) of the resistive loads L1, L2, and L3 is smaller than, for example, 5A (ampere), the correction value A is an average value of voltages applied to the resistive loads L1, L2, and L3 from 12.0V. It is determined to be higher (for example, 12.5 V).
When the reference current consumption of the resistive loads L1, L2, and L3 is larger than 5A, for example, the correction value A is an average value of voltages applied to the resistive loads L1, L2, and L3 lower than 12.0V (for example, 11.6V). It is determined to be.

When the duty ratio calculating means 5 calculates the duty ratio by the exact formula (1), the duty output unit 9 is a correction formula based on the given correction value A,
(12.0 / Power supply voltage value) ² x 100 ± A (%)
Thus, the duty ratio is corrected, and the switching elements S1, S2, and S3 are PWM-controlled by the corrected duty ratio.

For example, when the duty ratio calculating means 5 calculates the duty ratio by the polygonal line approximate expression (2) of the strict expression (1), the duty output unit 9 is a correction expression based on the given correction value A,
a × (power supply voltage value) + b ± A (%)
Thus, the duty ratio is corrected, and the switching elements S1, S2, and S3 are PWM-controlled by the corrected duty ratio.

Below, the example of operation | movement of the power supply control apparatus for vehicles of such a structure is demonstrated.
In this vehicle power supply control device, the voltage detection unit 4 detects the power supply voltage value output from the alternator 1 and the battery 2 through the power supply input circuit 3, and A / D converts the detected power supply voltage value to obtain a duty ratio. This is given to the arithmetic means 5.
The duty ratio calculation means 5 uses, for example, the given power supply voltage value and the predetermined voltage value 12.0 V, for example, a first-order approximate expression of the exact expression (1) a × (power supply voltage value) + b (%) (2)
Thus, the duty ratio is calculated and given to the duty output unit 9.

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 with a given duty ratio. As a result, the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.
The duty ratio detection unit 10 detects a voltage change of the power supply voltage PWM-controlled by the switching elements S1, S2, and S3 (a change point having a height relationship with a predetermined threshold) and a time between the voltage changes, and calculates a duty ratio. Part 11 is given.

The duty ratio calculation unit 11 calculates the duty ratio of the power supply voltage subjected to PWM control based on the voltage change detected by the duty ratio detection unit 10 and the time between the voltage changes, and supplies it to the duty ratio comparison unit 6.
The duty ratio comparison means 6 compares the duty ratio calculated by the duty ratio calculation unit 11 with the duty ratio given from the duty ratio calculation means 5 and gives the comparison result to the duty ratio correction means 7.

  The duty ratio correction unit 7 obtains a correction value A with reference to the table stored in the table storage unit 8 based on the given comparison result, and gives the obtained correction value A to the duty output unit 9. The duty output unit 9 corrects the given correction value A by adding (subtracting) it to the duty ratio given from the duty ratio calculating means 5, and PWMs the switching elements S1, S2, S3 by the corrected duty ratio. Control.

As a result, the duty output unit 9 can correct the equation (2) based on the given correction value A,
a × (power supply voltage value) + b ± A (%)
Thus, the duty ratio is corrected.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 with the corrected duty ratio, and applies the PWM-controlled power supply voltage to the resistance loads L1, L2, and L3.

(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, the power supply voltage value output from the alternator 1 and the battery 2 is detected and A / D converted by the voltage detection unit (means for detecting the voltage value) 4 through the power supply input circuit 3 to obtain a duty ratio. It is given to the arithmetic means 5.
The duty ratio calculation means 5 uses a given power supply voltage value and a predetermined voltage value (here, 12.0 V) to calculate a theoretical formula (strict formula).
(12.0 / Power supply voltage value) ² x 100 (%) (1)
Thus, the duty ratio is calculated and given to the duty output unit (PWM control circuit) 9.

In order to reduce the amount of calculation, the duty ratio calculation means 5 replaces the exact expression (1) with a linear approximation expression or a linear approximation expression of the exact expression (1) obtained in advance by the least square method or the like. It is also possible to calculate the duty ratio and give it to the duty output unit 9 by quadratic polynomial approximation.
First order approximate expression of exact expression (1) a × (power supply voltage value) + b (%) (2)
(A and b are arbitrary real numbers)
Thus, when the duty ratio y is calculated, the equation (2) becomes, for example, y = −8.976x + 201.4, and is graphed as shown in e of FIG. For comparison, the exact formula (1) is also shown as a graph (d in FIG. 6).

Broken line approximation formula of exact formula (1) a × (power supply voltage value) + b (%) (3)
(A and b are arbitrary real numbers determined for each predetermined voltage section)
Thus, when calculating the duty ratio, equation (3) becomes a broken line in which coefficients a and b are determined for every 0.1 V, for example, as shown in f of FIG. For comparison, the exact formula (1) is also shown as a graph (d in FIG. 7).

Quadratic polynomial approximation of exact expression (1) a × (power supply voltage value) ² + b × (power supply voltage value) + c (%) (4)
(A, b, and c are arbitrary real numbers)
Thus, when the duty ratio y is calculated, the equation (4) is, for example, y = 0.90662x ² −36.162x + 402.49, and is graphed as shown in FIG. For comparison, the exact formula (1) is also shown as a graph (d in FIG. 8).

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 according to the given duty ratio, and the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3. Here, when the duty ratio corrected by the duty ratio correction calculating means 7a described later is given, the duty output unit 9 selects the corrected duty ratio, and the switching element S1 is selected according to the selected duty ratio. , S2 and S3 are PWM-controlled.
The description of the duty ratio detection unit 10 and the duty ratio calculation unit 11 is omitted because it has been described in the first embodiment (FIG. 1).

The duty ratio comparison means 6 compares the duty ratio calculated by the duty ratio calculation section 11 and the duty ratio given from the duty ratio calculation means 5, and compares the comparison result (difference or ratio) with the duty ratio correction calculation means (correction). Means) to 7a.
The duty ratio correction calculation means 7a refers to the table stored in the table storage means 8a based on the given comparison result, and the duty ratio (12.0 / power supply voltage value) ² × 100 calculated by the duty ratio calculation means 5 A change value A for adding or subtracting the predetermined voltage value 12.0 of (%) is obtained.

Next, the duty ratio correction calculating means 7a uses the obtained change value A, the expression (5),
((12.0 ± A) / Power supply voltage value) ² × 100 (%) (5)
And the duty ratio is corrected, and the corrected duty ratio is given to the duty output unit 9.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 according to a given duty ratio.

The table stored in the table storage unit 8a is obtained by actually measuring or changing the change value A in the equation (5) calculated by the duty ratio correction calculation unit 7a in correspondence with the comparison result (difference or ratio) of the duty ratio comparison unit 6. Calculated based on calculation and stored.
When the reference consumption current (rated current) of the resistive loads L1, L2, and L3 is smaller than 5A, for example, the change value A is higher than the average value of the voltage applied to the resistive loads L1, L2, and L3 than 12.0V (for example, 12.5V).
When the reference current consumption of the resistive loads L1, L2, and L3 is larger than, for example, 5A, the change value A is lower than the average value of the voltage applied to the resistive loads L1, L2, and L3 than 12.0V (for example, 11.6V). It is determined to be.

  When the duty ratio calculating means 5 calculates the duty ratio by the exact formula (1), the duty ratio correction calculating means 7a corrects the duty ratio by the formula (5) based on the obtained change value A. . The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 based on the duty ratio corrected and calculated by the duty ratio correction calculation unit 7a.

  When the duty ratio calculating means 5 calculates the duty ratio by the primary approximate expression (2), the duty ratio correction calculating means 7a is based on the expression (2) if the obtained change value A = 0. The duty ratio is calculated by y = −8.976x + 201.4 (e in FIG. 6).

If the obtained change value A = 0.5, y = −9.1808x + 209.54
If the change value A = 1.0, y = −9.3799x + 217.69
If the change value A = 1.5, y = −9.5735x + 225.85
If the change value A = 2.0, y = −9.7619x + 234.03
If the change value A = 2.5, y = −9.9455x + 242.22
If the change value A = 3.0, y = -10.16x + 252.07
If the change value A = 3.5, y = -10.299x + 258.65
If the change value A = 4.0, y = -10.469x + 266.89
Thus, the graph of the correction formula of the primary approximation formula (2) moves in the positive direction of the y-axis as the change value A increases (FIG. 6). This is the same even when the duty ratio is calculated by the polygonal line approximation formula (3). As the change value A increases, the correction formula graph (f in FIG. 7) moves in the positive direction of the y-axis. (Figure 7).

When the duty ratio calculating means 5 calculates the duty ratio by quadratic polynomial approximation (4), the duty ratio correction calculating means 7a is based on the equation (4) if the obtained change value A = 0, for example: The duty ratio is calculated by y = 0.0.9062 ² −36.162x + 402.49 (g in FIG. 8).

If the obtained change value A = 0.5,
y = 0.9101x ² -36.938x + 418.81
If the change value A = 1.0,
y = 0.9134x < ² > -37.695x + 435.15
If the change value A = 1.5,
y = 0.9162x ² -38.434x + 451.52
If the change value A = 2.0,
y = 0.9186x ² -39.158x + 467.91
If the change value A = 2.5,
y = 0.9206x < ² > -39.865x + 484.33

If the change value A = 3.0,
y = 0.9225x < ² > -40.695x + 504.06
If the change value A = 3.5,
y = 0.9235x < ² > -41.237x + 517.24
If the change value A = 4.0,
y = 0.9245x < ² > -41.902x + 533.74
Thus, the correction equation graph of the quadratic polynomial approximation (4) moves in the positive direction of the y-axis as the change value A increases (FIG. 8).

Below, the example of operation | movement of the power supply control apparatus for vehicles of such a structure is demonstrated.
In this vehicle power supply control device, the voltage detection unit 4 detects the power supply voltage value output from the alternator 1 and the battery 2 through the power supply input circuit 3, and A / D converts the detected power supply voltage value to obtain a duty ratio. This is given to the arithmetic means 5.
The duty ratio calculation means 5 uses, for example, the given power supply voltage value and the predetermined voltage value 12.0 V, for example, a first-order approximate expression of the exact expression (1) a × (power supply voltage value) + b (%) (2)
Thus, the duty ratio is calculated and given to the duty output unit 9.

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 with a given duty ratio. As a result, the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.
The duty ratio detection unit 10 detects a voltage change of the power supply voltage PWM-controlled by the switching elements S1, S2, and S3 (a change point having a height relationship with a predetermined threshold) and a time between the voltage changes, and calculates a duty ratio. Part 11 is given.

The duty ratio calculation unit 11 calculates the duty ratio of the power supply voltage subjected to PWM control based on the voltage change detected by the duty ratio detection unit 10, the time between voltage changes, and the cycle of the PWM control, and the duty ratio comparison unit 6 To give.
The duty ratio comparison means 6 compares the duty ratio calculated by the duty ratio calculation unit 11 and the duty ratio given from the duty ratio calculation means 5, and gives the comparison result to the duty ratio correction calculation means 7a.

Based on the given comparison result, the duty ratio correction calculating means 7a refers to the table stored in the table storage means 8a to determine the change value A, and the correction value A is used to correct the primary approximation formula (2). The duty ratio is obtained by calculating the formula (first-order approximation formula of formula (5)) and given to the duty output unit 9.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 according to the given duty ratio, and supplies the PWM-controlled power supply voltage to the resistance loads L1, L2, and L3.

(Embodiment 3)
FIG. 9 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 power supply voltage value output from the alternator 1 and the battery 2 is detected and A / D converted by the voltage detector (means for detecting the voltage value) 4a through the power supply input circuit 3, and the duty ratio is It is given to the arithmetic means 5.
The duty ratio calculation means 5 uses a given power supply voltage value and a predetermined voltage value (here, 12.0 V), a theoretical formula (exact formula),
(12.0 / Power supply voltage value) ² x 100 (%) (1)
Thus, the duty ratio is calculated and given to the duty output unit (PWM control circuit) 9.

In order to reduce the amount of calculation, the duty ratio calculation means 5 replaces the exact expression (1) with a linear approximation expression or a linear approximation expression of the exact expression (1) obtained in advance by the least square method or the like. It is also possible to calculate the duty ratio and give it to the duty output unit 9 by quadratic polynomial approximation.
The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 according to the given duty ratio, and the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.

The duty ratio comparison means 6 compares the duty ratio calculated by the duty ratio calculation section 11 and the duty ratio given from the duty ratio calculation means 5, and the comparison result (difference or ratio) is detected voltage value changing means (voltage The value V is given to the means 12).
The detected voltage value changing means 12 refers to the table stored in the table storage means 8b based on the given comparison result, and the duty ratio calculated by the duty ratio calculating means 5 (12.0 / power supply voltage value) ² × 100. A change value B to be added to or subtracted from the power supply voltage value of (%) is obtained and given to the voltage detector 4a.

The voltage detector 4 a adds or subtracts the given change value B to the detected power supply voltage value, and gives the duty ratio calculation means 5 the changed power supply voltage value by adding or subtracting the change value B.
The duty ratio calculation means 5 is given the changed power supply voltage value, so that the equation (6)
(12.0 / (power supply voltage value ± B)) ² × 100 (%) (6)
And the duty ratio is corrected, and the corrected duty ratio is given to the duty output unit 9.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 according to a given duty ratio.

The table stored in the table storage unit 8b is measured or calculated by associating the change value B of the equation (6) calculated by the duty ratio calculation unit 5 with the comparison result (difference or ratio) of the duty ratio comparison unit 6, respectively. To find and remember.
When the reference consumption current (rated current) of the resistive loads L1, L2, and L3 is smaller than 5 A, for example, the change value B is higher than the average value of the voltage applied to the resistive loads L1, L2, and L3 by 12.0 V (for example, 12.5V).
When the reference consumption current of the resistive loads L1, L2, and L3 is larger than 5 A, for example, the change value B is lower than the average value of the voltage applied to the resistive loads L1, L2, and L3 than 12.0 V (for example, 11.6 V). It is determined to be.

  When the duty ratio is calculated by the exact formula (1), the duty ratio calculation means 5 corrects the duty ratio by the formula (6). The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 based on the duty ratio corrected and calculated by the duty ratio calculation means 5.

  When the duty ratio is calculated by the primary approximation formula (2), the duty ratio calculation means 5 is set to x of y = −8.976x + 201.4 (e in FIG. 6) based on the formula (2), for example. The duty ratio is calculated by substituting the voltage value ± B). This is the same even when the duty ratio is calculated by the polygonal line approximation formula (3). Substituting (power supply voltage value ± B) for x in the polygonal line approximation formula (3) (f in FIG. 7), Calculate the duty ratio.

When the duty ratio is calculated by quadratic polynomial approximation (4), for example, y = 0.90662x ² −36.162x + 402.49 (g in FIG. 8) based on the formula (4). The duty ratio is calculated by substituting (power supply voltage ± B) for x.
The other configuration of the vehicle power supply control device according to the third embodiment is the same as the configuration of the vehicle power supply control device described in the second embodiment (FIG. 5), and a description thereof will be omitted. However, in the third embodiment, the duty ratio correction calculation unit 7a and the table storage unit 8a of FIG. 5 do not exist, and the voltage detection unit 4 is replaced with the voltage detection unit 4a.

Below, the example of operation | movement of the power supply control apparatus for vehicles of such a structure is demonstrated.
In this vehicle power supply control device, the voltage detection unit 4a detects the power supply voltage value output from the alternator 1 and the battery 2 through the power supply input circuit 3, and A / D converts the detected power supply voltage value to obtain a duty ratio. This is given to the arithmetic means 5.
The duty ratio calculation means 5 uses, for example, the given power supply voltage value and the predetermined voltage value 12.0 V, for example, a first-order approximate expression of the exact expression (1) a × (power supply voltage value) + b (%) (2)
Thus, the duty ratio is calculated and given to the duty output unit 9.

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 with a given duty ratio. As a result, the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.
The duty ratio detection unit 10 detects a voltage change of the power supply voltage PWM-controlled by the switching elements S1, S2, and S3 (a change point having a height relationship with a predetermined threshold) and a time between the voltage changes, and calculates a duty ratio. Part 11 is given.

The duty ratio calculation unit 11 calculates the duty ratio of the power supply voltage subjected to PWM control based on the voltage change detected by the duty ratio detection unit 10, the time between voltage changes, and the cycle of the PWM control, and the duty ratio comparison unit 6 To give.
The duty ratio comparison unit 6 compares the duty ratio calculated by the duty ratio calculation unit 11 and the duty ratio given from the duty ratio calculation unit 5, and gives the comparison result to the detection voltage value change unit 12.

Based on the given comparison result, the detected voltage value correcting unit 12 refers to the table stored in the table storage unit 8b to determine the change value B, and provides the calculated change value B to the voltage detection unit 4a.
The voltage detection unit 4 a changes the detected power supply voltage value by adding or subtracting the change value B, and supplies the changed (power supply voltage value ± B) to the duty ratio calculation means 5.

Based on the given (power supply voltage value ± B), the duty ratio calculation means 5 is based on the formula (2) a × (power supply voltage value ± B) + b (%)
Is calculated to obtain the duty ratio, which is given to the duty output unit 9.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 according to the given duty ratio, and supplies the PWM-controlled power supply voltage to the resistance loads L1, L2, and L3.

(Embodiment 4)
FIG. 10 is a block diagram showing a schematic configuration of the fourth embodiment of the vehicle power supply control device according to the present invention.
In this vehicle power supply control device, the power supply voltage value output from the alternator 1 and the battery 2 is detected and A / D converted by the voltage detector (voltage value detecting means) 4 through the power supply input circuit (filter circuit) 3a. Is provided to the duty ratio calculation means 5.
The duty ratio calculation means 5 uses a given power supply voltage value and a predetermined voltage value (here, 12.0 V), a theoretical formula (exact formula),
(12,0 / power supply voltage value) ² × 100 (%) (1)
Thus, the duty ratio is calculated and given to the duty output unit (PWM control circuit) 9.

In order to reduce the amount of calculation, the duty ratio calculation means 5 replaces the exact expression (1) with a linear approximation expression or a linear approximation expression of the exact expression (1) obtained in advance by the least square method or the like. It is also possible to calculate the duty ratio and give it to the duty output unit 9 by quadratic polynomial approximation.
The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 according to the given duty ratio, and the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.

The duty ratio comparison means 6 compares the duty ratio calculated by the duty ratio calculation section 11 and the duty ratio given from the duty ratio calculation means 5, and compares the comparison result (difference or ratio) with a time constant adjustment means (time constant). (Means for changing) 13.
Based on the given comparison result, the time constant adjusting unit 13 refers to the table stored in the table storage unit 8c and obtains a parameter for adjusting the time constant of the power input circuit 3a.

The time constant adjusting means 13 switches and adjusts the time constant of the power input circuit 3a based on the obtained parameters.
The voltage detection unit 4 detects the power supply voltage value that is input to and output from the power supply input circuit 3 a having the adjusted time constant, and supplies it to the duty ratio calculation means 5.
The duty ratio calculating means 5 calculates the equation (1) based on the supplied power supply voltage value to correct the duty ratio, and gives the corrected duty ratio to the duty output unit 9.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 according to a given duty ratio.

The power input circuit 3a has a plurality of types of time constant circuits composed of a resistance element, a capacitor, and a coil, and these time constants are based on actual measurement or calculation corresponding to the comparison result of the duty ratio comparison means 6. It has been established.
The table stored in the table storage unit 8c stores parameters for the time constant adjusting unit 13 to switch the time constant circuit of the power input circuit 3a according to the comparison result of the duty ratio comparison unit 6 in correspondence with the comparison result. doing.

When the reference current consumption (rated current) of the resistive loads L1, L2, and L3 is smaller than 5 A, for example, each time constant of the power input circuit 3a is 12.2 in the average value of the voltage applied to the resistive loads L1, L2, and L3. It is determined to be higher than 0V (for example, 12.5V).
When the reference current consumption of the resistive loads L1, L2, and L3 is larger than 5A, for example, the time constant of the power input circuit 3a is such that the average value of the voltages applied to the resistive loads L1, L2, and L3 is lower than 12.0V (for example, 11.6V).

When the duty ratio is calculated by a strict expression, the duty ratio calculation means 5 corrects the duty ratio by the expression (1). The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 based on the duty ratio calculated by the duty ratio calculation unit 5.
The duty ratio calculating means 5 calculates the duty ratio by the expression (2) when the duty ratio is calculated by the primary approximation expression. When the duty ratio is calculated by the broken line approximation formula, the duty ratio is calculated by formula (3).

When the duty ratio is calculated by quadratic polynomial approximation, the duty ratio calculation means 5 calculates the duty ratio by the equation (4).
The other configuration of the vehicle power supply control device according to the fourth embodiment is the same as the configuration of the vehicle power supply control device described in the first embodiment (FIG. 1), and thus the description thereof is omitted. However, in the fourth embodiment, the duty ratio correction means 7 and the table storage means 8 of FIG. 1 do not exist, the time constant adjustment means 13 and the table storage means 8c are added, and the power input circuit 3 is the power input circuit 3a. Has been replaced.

Below, the example of operation | movement of the power supply control apparatus for vehicles of such a structure is demonstrated.
In this vehicle power supply control device, the voltage detection unit 4 detects the power supply voltage value output from the alternator 1 and the battery 2 through the power supply input circuit 3a, A / D converts the detected power supply voltage value, and the duty ratio This is given to the arithmetic means 5.
The duty ratio calculation means 5 uses, for example, the given power supply voltage value and the predetermined voltage value 12.0 V, for example, a first-order approximate expression of the exact expression (1) a × (power supply voltage value) + b (%) (2)
Thus, the duty ratio is calculated and given to the duty output unit 9.

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 with a given duty ratio. As a result, the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.
The duty ratio detection unit 10 detects a voltage change of the power supply voltage PWM-controlled by the switching elements S1, S2, and S3 (a change point having a height relationship with a predetermined threshold) and a time between the voltage changes, and calculates a duty ratio. Part 11 is given.

The duty ratio calculation unit 11 calculates the duty ratio of the power supply voltage subjected to PWM control based on the voltage change detected by the duty ratio detection unit 10, the time between voltage changes, and the cycle of the PWM control, and the duty ratio comparison unit 6 To give.
The duty ratio comparison unit 6 compares the duty ratio calculated by the duty ratio calculation unit 11 and the duty ratio given from the duty ratio calculation unit 5, and gives the comparison result to the time constant adjustment unit 13.

Based on the given comparison result, the time constant adjusting unit 13 refers to the table stored in the table storage unit 8c to obtain a parameter, and switches the time constant circuit of the power input circuit 3a based on the obtained parameter.
The voltage detection unit 4 detects the power supply voltage value through the switched time constant circuit of the power supply input circuit 3 a and supplies the detected power supply voltage value to the duty ratio calculation means 5.

The duty ratio calculation means 5 is based on the given power supply voltage value (2),
a x power supply voltage value + b (%)
Is calculated to obtain a duty ratio, which is given to the output unit 9.
The duty output unit 9 performs PWM control of the switching elements S1, S2, and S3 according to the given duty ratio, and supplies the PWM-controlled power supply voltage to the resistance loads L1, L2, and L3.
In the fourth embodiment, it is possible to suppress the influence on the voltage fluctuation due to the PWM control frequency of the duty output unit 9, the sensitive duty ratio fluctuation, and the oscillation phenomenon.

(Embodiment 5)
FIG. 11 is a block diagram showing a schematic configuration of the fifth embodiment of the vehicle power supply control device according to the present invention.
In this vehicle power supply control device, the power supply voltage value output from the alternator 1 and the battery 2 is detected and A / D converted by the voltage detection unit (means for detecting the voltage value) 4 through the power supply input circuit 3 to obtain a duty ratio. It is given to the arithmetic means 5.
The duty ratio calculation means 5 uses a given power supply voltage value and a predetermined voltage value (here, 12.0 V), a theoretical formula (exact formula),
(12,0 / power supply voltage value) ² × 100 (%) (1)
Thus, the duty ratio is calculated and given to the duty output unit (switching circuit) 9.

In order to reduce the amount of calculation, the duty ratio calculation means 5 replaces the exact expression (1) with a linear approximation expression or a linear approximation expression of the exact expression (1) obtained in advance by the least square method or the like. It is also possible to calculate the duty ratio and give it to the duty output unit 9 by quadratic polynomial approximation.
First order approximate expression of exact expression (1) a × (power supply voltage value) + b (%) (2)
(A and b are arbitrary real numbers)
Thus, when calculating the duty ratio y, the equation (2) becomes, for example, y = −8.976x + 201.4, and the graph is as shown in FIG. For comparison, the exact formula (1) is also shown in a graph.

Broken line approximation formula of exact formula (1) a × (power supply voltage value) + b (%) (3)
(A and b are arbitrary real numbers determined for each predetermined voltage section)
Thus, when calculating the duty ratio, equation (3) becomes a broken line in which coefficients a and b are determined for every 0.1 V, for example, as shown in FIG. For comparison, the exact formula (1) is also shown in a graph.

Quadratic polynomial approximation of exact expression (1) a × (power supply voltage value) ² + b × (power supply voltage value) + c (%) (4)
(A, b, and c are arbitrary real numbers)
Thus, when the duty ratio y is calculated, the equation (4) is, for example, y = 0.90662x ² −36.162x + 402.49, which is graphed as shown in FIG. For comparison, the exact formula (1) is also shown in a graph.

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 according to the given duty ratio, and the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.
Here, when each change time at the ON time point and / or the OFF time point given by the timing changing unit 15 described later is not 0, the duty output unit 9 is given the ON time point based on the given duty ratio. Further, the PWM control is performed by changing the ON time point and / or the OFF time point of the switching elements S1, S2, and S3 according to the change time at the OFF time point.

The output voltage detection unit (rise time detection means, fall time detection means) 10a detects the voltage value given to the resistance loads L1, L2, L3 by PWM control of the switching elements S1, S2, S3, and detects the timing. Section (rise time detection means, fall time detection means) 16.
The timing detection unit 16 detects the timing at which the given voltage value exceeds, for example, 90% (first voltage value) of the voltage value detected by the voltage detection unit 4, and the voltage value detected by the voltage detection unit 4, for example, 10 Timing that falls below% (second voltage value) is detected and transmitted to timing comparison means (rise time detection means, fall time detection means) 14.

  The timing comparison means 14 turns the switching elements S1, S2 and S3 on and off based on the transmitted timings above and below (FIG. 12B) and the PWM control period given from the duty output unit 9. And the rise time tr and fall time tf of the pulse are calculated from the difference therebetween.

FIG. 12 is a waveform diagram for explaining an example of the operation of the vehicle power supply control device, and schematically shows the pulse rise time tr and the fall time tf. Since it is difficult to detect the falling edge, 90% and 10% of the voltage value detected by the voltage detector 4 is detected.
Further, the voltage change of the power supply voltage may be different for each of the switching elements S1, S2, and S3, but here, an intermediate value is obtained and used.

The timing comparison means 14 gives the calculated rise time tr and fall time tf to the timing change means (on time change means, off time change means) 15.
The timing changing means 15 refers to the rise time table (first table) 8e stored in the table storage means (on time change means) 8d based on the given rise time tr, and the switching elements S1, S2 and S3 are turned on. The on-time change time Atr for changing the time to perform is obtained.
The timing changing means 15 refers to the falling time table (second table) 8f stored in the table storage means (off time changing means) 8d based on the given falling time tf, and switches the switching elements S1, S2, S3. OFF time change time Atf for changing the time point at which is turned off is obtained.

When the reference consumption current (rated current) of the resistive loads L1, L2, and L3 is smaller than 5 A, for example, the on time change time Atr and the off time change time Atf (FIG. 12C) are determined as follows.
The on-time change time Atr is the time when the voltage applied to the resistance loads L1, L2, and L3 reaches the voltage value detected by the voltage detector 4 (FIG. 12D), and the time when the switching elements S1, S2, and S3 are turned on ( It is determined by actual measurement or calculation (for example, tr / 0.9, etc.) according to the rise time tr so as to be earlier than FIG. 12A).

The off time change time Atf is such that the time when the voltage applied to the resistive loads L1, L2, and L3 reaches 0V (FIG. 12D) is later than the time when the switching elements S1, S2, and S3 are turned off (FIG. 12A). It is determined by actual measurement or calculation (for example, tf / 0.9, etc.) according to the fall time tf.
As a result, the on-time change time Atr and the off-time change time Atf are determined such that the average value of the voltage applied to the resistance loads L1, L2, and L3 is higher than 12.0V (for example, 12.5V).

When the reference consumption current of the resistive loads L1, L2, and L3 is larger than 5A, for example, the on time change time Atr and the off time change time Atf (FIG. 12C) are determined as follows.
The on-time change time Atr is the time when the voltage applied to the resistance loads L1, L2, and L3 reaches the voltage value detected by the voltage detector 4 (FIG. 12D), and the time when the switching elements S1, S2, and S3 are turned on ( It is determined by actual measurement or calculation (for example, tr / 0.9, etc.) according to the rise time tr so as to be later than FIG.

The off time change time Atf is such that the time when the voltage applied to the resistive loads L1, L2, and L3 reaches 0V (FIG. 12D) is earlier than the time when the switching elements S1, S2, and S3 are turned off (FIG. 12A). It is determined by actual measurement or calculation (for example, tf / 0.9, etc.) according to the fall time tf.
As a result, the on-time change time Atr and the off-time change time Atf are determined such that the average value of the voltage applied to the resistance loads L1, L2, and L3 is lower than 12.0V (for example, 11.6V).

The timing changing unit 15 provides the duty output unit 9 with the obtained on time change time Atr and off time change time Atf.
Based on the duty ratio given from the duty ratio calculation means 5, the duty output unit 9 advances the switching point S1, S2, S2, S2 by turning the turn-on time and turn-off time earlier by the time change time Atr and the turn-off time change time Atf. PWM control of S3 is performed.

Below, the example of operation | movement of the power supply control apparatus for vehicles of such a structure is demonstrated.
In this vehicle power supply control device, the voltage detection unit 4 detects the power supply voltage value output from the alternator 1 and the battery 2 through the power supply input circuit 3, and A / D converts the detected power supply voltage value to obtain a duty ratio. This is given to the arithmetic means 5.
The duty ratio calculation means 5 uses, for example, the given power supply voltage value and the predetermined voltage value 12.0 V, for example, a first-order approximate expression of the exact expression (1) a × (power supply voltage value) + b (%) (2)
Thus, the duty ratio is calculated and given to the duty output unit 9.

The duty output unit 9 performs PWM control of the switching elements (PWM control circuits) S1, S2, and S3 with a given duty ratio. As a result, the PWM-controlled power supply voltage is applied to the resistance loads L1, L2, and L3.
In the output voltage detection unit 10 a, the switching elements S 1, S 2, and S 3 perform PWM control, detect voltage values applied to the resistance loads L 1, L 2, and L 3, and apply them to the timing detection unit 16.
The timing detection unit 16 detects the timing when the given voltage value exceeds 90% of the voltage value detected by the voltage detection unit 4 and the timing when the voltage value detected by the voltage detection unit 4 falls below 10% of the voltage value detected by the voltage detection unit 4, for example. Detected and transmitted to the timing comparison means 14.

  The timing comparison means 14 turns the switching elements S1, S2 and S3 on and off based on the transmitted timings above and below (FIG. 12B) and the PWM control period given from the duty output unit 9. And the rise time tr and fall time tf of the pulse are calculated from the difference therebetween.

The timing comparison means 14 gives the calculated rise time tr and fall time tf to the timing change means 15.
The timing changing unit 15 refers to the rise time table 8e based on the given rise time tr and obtains an on time change time Atr for changing the time when the switching elements S1, S2, and S3 are turned on.
The timing changing unit 15 refers to the falling time table 8f based on the given falling time tf, and obtains an off time changing time Atf for changing the time when the switching elements S1, S2, and S3 are turned off.

The timing changing unit 15 provides the duty output unit 9 with the obtained on time change time Atr and off time change time Atf.
Based on the duty ratio given from the duty ratio calculation means 5, the duty output unit 9 advances the turn-on time and turn-off time (FIG. 12A) by the turn-on time change time Atr and the turn-off time change time Atf (FIG. 12). 12C), the switching elements S1, S2 and S3 are PWM-controlled (FIG. 12D).

  In the present embodiment, the time when the switching elements S1, S2, S3 are turned on and off is changed by the on time change time Atr and the off time change time Atf, but the on time change time Atr It is also possible to change only the point in time when the switching elements S1, S2, S3 are turned on. It is also possible to change only the time when the switching elements S1, S2, S3 are turned off by the off time changing time Atf.

In the above-described first to fifth embodiments, the reference current consumption of the resistive loads L1, L2, and L3 is divided into cases, for example, smaller / larger than 5A, but instead, the resistive loads L1, L2, and L3 are divided into cases. It is also possible to classify cases by providing an intermediate portion such that the reference current consumption of L3 is, for example, less than 8A / 1010A.
In the above-described first to fifth embodiments, when the reference power consumption of the resistive loads L1, L2, and L3 is different, the above-described vehicle power control device is used for each of the resistive loads L1, L2, and L3. Alternatively, for each of the resistive loads L1, L2, and L3, only a possible portion may be shared using the above-described vehicle power supply control device.

1 Alternator (car power supply)
2 Battery (vehicle power supply)
3 Power input circuit 3a Power input circuit (means for changing, filter circuit)
4 Voltage detector (means to detect voltage value)
4a Voltage detector (means for detecting and changing voltage value)
5 Duty ratio calculation means 6 Duty ratio comparison means (comparison means)
7 Duty ratio correction means (correction means)
7a Duty ratio correction calculation means (means for changing)
8, 8a to 8d Table storage means 9 Duty output section (PWM control circuit)
10 Duty ratio detection unit (means for detecting the duty ratio)
10a Output voltage detection section 11 Duty ratio calculation section (means for detecting duty ratio)
12 Detection voltage value changing means (changing means)
13 Time constant adjustment means (means to change)
14 Timing comparison means (rise time detection means, fall time detection means)
15 Timing changing means (means for changing)
16 Timing detector (rise time detection means, fall time detection means)
L1, L2, L3 Resistive load S1, S2, S3 Switching element (PWM control circuit)

Claims (10)

By means of detecting the voltage value of the in-vehicle power supply, the duty ratio calculating means for calculating the duty ratio based on the power supply voltage value detected by the means and a predetermined voltage value, and the duty ratio calculated by the duty ratio calculating means In a vehicle power supply control device including a PWM control circuit that PWM-controls a voltage from a power supply and applies the voltage to a resistance load,
A means for detecting a duty ratio of a voltage applied to the resistance load; a comparison means for comparing the duty ratio detected by the means; and a duty ratio calculated by the duty ratio calculation means; and a rated power of the resistance load is predetermined. If it is smaller than the value such that said average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and when the rated power of the resistive load is larger than a predetermined value, the resistor Means for correcting a duty ratio controlled by the PWM control circuit based on a comparison result of the comparison means so that an average value of a voltage applied to a load is lower than the predetermined voltage value. Vehicle power supply control device. A means for detecting a power supply voltage value V of the in-vehicle power supply, a duty ratio calculating means for calculating a duty ratio (predetermined voltage value / V) ² × 100, and a PWM for controlling the voltage from the in-vehicle power supply to the resistance load by PWM control In a vehicle power supply control device comprising a control circuit,
A means for detecting a duty ratio of a voltage applied to the resistance load; a comparison means for comparing the duty ratio detected by the means; and a duty ratio calculated by the duty ratio calculation means; and a rated power of the resistance load is predetermined. If it is smaller than the value such that said average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and when the rated power of the resistive load is larger than a predetermined value, the resistor Means for changing a predetermined voltage value used by the duty ratio calculation means based on a comparison result of the comparison means so that an average value of a voltage applied to a load is lower than the predetermined voltage value. A vehicle power supply control device. A means for detecting a power supply voltage value V of the in-vehicle power supply, a duty ratio calculating means for calculating a duty ratio (predetermined voltage value / V) ² × 100, and a PWM for controlling the voltage from the in-vehicle power supply to the resistance load by PWM control In a vehicle power supply control device comprising a control circuit,
A means for detecting a duty ratio of a voltage applied to the resistance load; a comparison means for comparing the duty ratio detected by the means; and a duty ratio calculated by the duty ratio calculation means; and a rated power of the resistance load is predetermined. If it is smaller than the value such that said average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and when the rated power of the resistive load is larger than a predetermined value, the resistor Means for changing the power supply voltage value V used by the duty ratio calculation means based on the comparison result of the comparison means so that the average value of the voltage applied to the load is lower than the predetermined voltage value. A vehicle power supply control device. Means for detecting the voltage value of the in-vehicle power supply through a filter circuit; duty ratio calculating means for calculating a duty ratio (predetermined voltage value / V) ² × 100 using the power supply voltage value V detected by the means; In a vehicle power supply control device comprising a PWM control circuit that applies PWM control to a resistance load by controlling the voltage of a power supply,
A means for detecting a duty ratio of a voltage applied to the resistance load; a comparison means for comparing the duty ratio detected by the means; and a duty ratio calculated by the duty ratio calculation means; and a rated power of the resistance load is predetermined. If it is smaller than the value such that said average value of the voltage applied to the resistive load is higher than the predetermined voltage value, and when the rated power of the resistive load is larger than a predetermined value, the resistor A vehicle power supply comprising: a means for changing a time constant of the filter circuit based on a comparison result of the comparison means so that an average value of a voltage applied to a load is lower than the predetermined voltage value. Control device. The means for detecting the voltage value of the in-vehicle power supply, the duty ratio calculating means for calculating the duty ratio based on the power supply voltage value detected by the means and the predetermined voltage value, and the duty ratio calculated by the duty ratio calculating means, In a vehicle power supply control device comprising a switching circuit that PWM-controls the voltage of an in-vehicle power supply and applies it to a resistance load,
A voltage applied to the resistance load is a rise time detecting means for detecting a rise time that rises from an on time of the switching circuit to a first voltage value based on the power supply voltage value; and from an off time of the switching circuit, A fall time detecting means for detecting a fall time when the voltage falls to a second voltage value based on the power supply voltage value; and when the rated power of the resistive load is smaller than a predetermined value, the voltage is when rising up 1 voltage value, the early kuna so that from the turn-on time, and if the rated power of the resistive load is larger than a predetermined value, the time when the voltage rises up to a first voltage value as slower than the turn-on time, based on the rise time the rise time detected by the detecting means and means for varying the point at which the switching circuit is turned on, the rating of the resistor load If the force is less than the predetermined value, when the voltage falls to a second voltage value, the slow kuna so that from the off-time, also, the rated power of the resistive load is larger than a predetermined value In this case, the time point when the switching circuit is turned off is changed based on the fall time detected by the fall time detection means so that the time point when the voltage falls to the second voltage value is earlier than the off time point. A vehicle power supply control device. The duty ratio calculating means is configured to calculate a duty ratio using an expression using the power supply voltage value and a predetermined voltage value, (predetermined voltage value / power supply voltage value) ² × 100. Item 6. The vehicle power supply control device according to Item 1 or 5. The duty ratio calculating means calculates a duty ratio using an arithmetic expression using the power supply voltage value and a predetermined voltage value, and a first order approximate expression of (predetermined voltage value / power supply voltage value) ² × 100. The vehicular power supply control device according to any one of claims 1 to 5, which is configured. The duty ratio calculating means is configured to calculate a duty ratio using an arithmetic expression using the power supply voltage value and a predetermined voltage value, and a (predetermined voltage value / power supply voltage value) ² × 100 broken line approximation expression. The vehicle power supply control device according to any one of claims 1 to 5. The duty ratio calculating means calculates the duty ratio using a calculation formula using the power supply voltage value and a predetermined voltage value, and a quadratic polynomial approximation of (predetermined voltage value / power supply voltage value) ² × 100. The vehicular power supply control device according to any one of claims 1 to 5, which is configured. A plurality of the vehicle power supply control devices according to claim 1 are provided, and the plurality of vehicle power supply control devices are configured to perform PWM control of voltages to resistance loads having different rated powers. A vehicle power supply control device, characterized in that:

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