JP6539100B2 - Power supply control device for vehicle - Google Patents

Description

  The present invention relates to a power supply control device for a vehicle that supplies power to a load and shuts off the load by turning on and off the semiconductor switching element on the wire based on the temperature of the wire that supplies power from the power supply to the load.

  In a vehicle, conventionally, power supply from a power source to a load is controlled by turning on and off a semiconductor switching element. Among them, there are those using an intelligent power device (IPD) to which a passing current detection function or a self-protection function against an overcurrent is added as a semiconductor switching element.

  If the IPD is used as a semiconductor switching element, for example, the temperature of the wire connecting the power supply and the load is estimated using the passing current detected by the passing current detection function, and when the temperature reaches a predetermined upper limit temperature It is also possible to operate to turn off the semiconductor switching element to cut off the power supply to the load for protection (for example, Patent Document 1).

  Also, for example, when it is not possible to supply a load with sufficient current to drive a load with one IPD, it is also proposed that a plurality of IPDs of the same standard be connected in parallel and interposed between the power supply and the load. It is done. In this proposal, by matching the wiring resistances of the wiring patterns passing through each IPD, the magnitude of the current flowing in each IPD is made the same, and the current is prevented from flowing in a specific IPD. (For example, patent document 2).

JP, 2009-130944, A JP 2001-310720 A

  However, in view of the restriction on the layout of the wiring patterns on the substrate, it is practically difficult to match the wiring resistances of the wiring patterns. Therefore, even if a plurality of IPDs of the same standard are connected in parallel and interposed between the power supply and the load, it is difficult to make the current flow evenly through each IPD.

  In addition, even for a plurality of loads that need to be driven under the same conditions, such as the headlights of the left and right of the vehicle, for example, the resistances of the wiring corresponding to each load are made to match each other to supply power under the same conditions by the IPD. Is considered. However, in this case as well, it is actually difficult to make the wiring resistance consistent by unifying the wiring route length, the wiring type, and the layout of the wiring, and the current flowing through each IPD may vary and the output of each load may vary. is there.

  Furthermore, there are inter-individual variations in the on resistance of the semiconductor switching element of the IPD and the circuit resistance of the internal circuit. Such variations among individuals of IPDs may also cause variations in power supplied to a load via each IPD.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to connect a plurality of electric wires provided with semiconductor switching elements in parallel with a power supply of a vehicle and use them as a power supply path for a load. To provide a power supply control device for a vehicle capable of matching the power supplied from the power supply to the load through each wire even if the switching elements have variation among individuals or the wiring resistance of each wire is different. It is in.

In order to achieve the above object, a vehicle power control apparatus of the present invention described in claim 1 is:
By turning off the semiconductor switching element provided in each of a plurality of wires connected in parallel to the power supply of the vehicle, Te power controller odor vehicle to cut off power supplied to the load via the respective wires from the power supply,
A power supply voltage detection unit that detects a voltage of the power supply;
A current measuring unit for measuring a passing current through pre Symbol of the semiconductor switching devices, respectively,
And wire power calculating section for calculating the detected voltage Toka et of the the measured current of the current measuring unit supply voltage detection unit, before Symbol each actual supply electric power value of the power supplied to the load by the electric wires respectively,
Each of the electric wires has a design value of a target supplied power per unit time from the electric wire to the load, which is determined based on a passing current serving as a reference of each of the semiconductor switching elements determined from the detected voltage and the resistance of the load. and the duty ratio determining unit for determining said to match each actual supply electric power value to the load, the duty ratio of the PWM control before Symbol the semiconductor switching devices of each wire respectively from,
A PWM control unit that performs PWM control of each of the semiconductor switching elements according to the duty ratio determined by the duty ratio determination unit corresponding to each of the semiconductor switching elements;
And the like.

According to the vehicle power supply control device of the present invention according to claim 1, passing current and voltage Toka et of the detected power supply voltage detection unit of the semiconductor switching elements measured by the current measuring unit, each of the semiconductor switching A passing current to be a reference of the element is determined. Then, based on the current passing through Motoma' criteria each actual supply electric power value of the power supplied to the al load or each conductive line is calculated for each wire. Further, the power supplied to the load of each electric wire issued calculated, the target design value of power supplied per unit time from the electric wire, which is determined based on the resistance of the sensing voltage and load of the power supply voltage detecting unit to the load one The duty ratio in the PWM control of the semiconductor switching element for each wire is determined for the purpose of matching.

The design value of the target supply electric power for lower wires than the actual supply electric power value to the loads calculated from the passing current and the voltage of the power detected by the power supply voltage detection unit of the semiconductor switching elements measured by the current measuring unit In this case, the duty ratio in PWM control for matching the actual supply power value to the load to the target supply power lower than that decreases the on-duty.

Conversely, the design value of the target supply electrical power is higher than the actual supply electric power value to the loads calculated from the passing current and the voltage of the power detected by the power supply voltage detection unit of the semiconductor switching elements measured by the current measuring unit wire The duty ratio in the PWM control to make the actual supply power value to the load match the target supply power higher than that is the content that increases the on-duty.

Anyway the supply power to the load by the wire calculated from the voltage measurement and the power supply voltage detected by power detection section of the current passing through the semiconductor switching element is detected by supply voltage detecting unit By performing PWM control of the semiconductor switching element at a duty ratio that matches the design value of the target supply power determined based on the voltage of the power supply and the resistance of the load, the supply power to the load by each wire calculated thereafter can be obtained. Become a match.

  Therefore, when a plurality of electric wires provided with semiconductor switching elements are connected in parallel to the power supply of the vehicle and used as a power supply path for the load, there is a variation among the individual semiconductor switching elements, or the wiring resistance of each electric wire Even if there is a difference, it is possible to match the power supplied from the power source to the load via each wire.

  According to the present invention, when a plurality of electric wires provided with the semiconductor switching elements are connected in parallel to the power supply of the vehicle and used as a power supply path for the load, there is individual variation among the semiconductor switching elements. Even if there is a difference in the wiring resistance, the power supplied from the power supply to the load can be made to match through the respective electric wires.

BRIEF DESCRIPTION OF THE DRAWINGS It is a circuit diagram which shows the fundamental structure of the power supply control apparatus for vehicles which concerns on one Embodiment of this invention. It is a functional block diagram which shows typically the process performed in the control part of FIG. It is a timing chart which shows the procedure at the time of the electric current detection part of FIG. 2, and a DUTY ratio detection part detecting the passing current of load, and its duty ratio. It is a flowchart which shows the operation | movement performed in the power supply control apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing a basic configuration of a power supply control device according to an embodiment of the present invention.

  The power supply control device 1 of the present embodiment (corresponding to the power supply control device for vehicles in the claims) has two wires 51 and 52 having the same or different wiring resistance from the power supply B mounted on the vehicle (not shown) to the load 3. The control unit 11 controls the operation of the intelligent power devices (IPD) 131 and 132 provided on the electric wires 51 and 52 for turning on and off the power supply via the parallel circuit 5. In the present embodiment, the load 3 is, for example, an electrical component such as a headlight.

  Each intelligent power device (IPD) 131, 132 incorporates a semiconductor switching element a and a current measuring unit b. The semiconductor switching element a is turned on and off by drive signals DR1 and DR2 output from the control unit 11 to the IPDs 131 and 132 in response to the on / off operation of the input switch SW. The current measuring unit b measures the passing current flowing through the corresponding electric wires 51 and 52 through the semiconductor switching element a at the time of ON.

  The semiconductor switching elements a of the IPDs 131 and 132 control the control unit 11 when the passing current measured by the current measurement unit b rises to the cutoff current set for the wires 51 and 52 for overcurrent protection. Is turned off.

  The control unit 11 is configured by a microcomputer, a custom IC or the like that realizes various processes by execution of a program. The control unit 11 has a power supply voltage input terminal BATT, an input terminal IN, output terminals OUT1 and OUT2, and detection current input terminals SI1 and SI2.

  The power supply voltage input terminal BATT is a terminal for monitoring the voltage of the power supply B, and a voltage value VB obtained by dividing the power supply voltage by the voltage dividing resistors R1 and R2 is input to the power supply voltage input terminal BATT. The input terminal IN is a terminal for monitoring the on / off state of the input switch SW, and receives the switch signal S according to the on / off state of the input switch SW.

  In principle, when the switch signal S at the input terminal IN is in the on state, the output terminals OUT1 and OUT2 are drive signals DR1 and DR1 for turning on the semiconductor switching elements a of the corresponding IPDs 131 and 132 by DC drive or PWM drive. Output DR2 respectively. The current detection signals I1 and I2 indicating the value of the passing current measured by the current measurement unit b of the corresponding IPDs 131 and 132 are input to the detection current input terminals SI1 and SI2, respectively.

  The control unit 11 turns on the semiconductor switching elements a of the corresponding IPDs 131 and 132 by DC drive or PWM drive by the drive signals DR1 and DR2 output from the output terminals OUT1 and OUT2.

  In addition, the control unit 11 controls the current passing through the wires 51 and 52 indicated by the current detection signals I1 and I2 from the current measuring unit b of the IPDs 131 and 132 input to the detection current input terminals SI1 and SI2, respectively. When it rises to a predetermined cutoff current with respect to 52, the control unit 11 forcibly terminates the output of the drive signals DR1 and DR2 and forcibly turns off the semiconductor switching elements a of the corresponding IPDs 131 and 132.

  By the way, in the ON resistance of the semiconductor switching element a of the IPDs 131 and 132 and the circuit resistance of the internal circuit, there is a variation between individuals. Therefore, even between the individual IPDs 131 and 132 in which the semiconductor switching element a is turned on under the same condition, variations may occur in the passing currents of the electric wires 51 and 52 measured by the current measurement unit b.

  In addition, due to the mismatch between the wire length, the wire type, and the layout of the wiring between the electric wires 51 and 52, the wiring resistance may vary. If such a variation in wiring resistance exists, even if there is no variation between individuals in the on resistance of the semiconductor switching element a of the IPDs 131 and 132 or the circuit resistance of the internal circuit, each of the components measured by the current measuring unit b Variations may occur in the passing currents of the wires 51 and 52.

  If the passing currents of the wires 51 and 52 have such variations, even if the control unit 11 turns on and off the semiconductor switching elements a of the IPDs 131 and 132 by PWM control with the same duty ratio, There is a variation in the power supplied to the

  Then, the temperature of the electric wires 51 and 52 rises to the cut-off temperature and the IPDs 131 and 132 are more easily cut off as the electric wires 51 and 52 with larger supplied electric power to the load 3 are supplied. The current may concentrate and flow to the IPDs 131 and 132 of the electric wires 51 and 52 which continue to cause abnormal heat generation and resistance deterioration.

  Therefore, the control unit 11 calculates the voltage of the power supply B from the voltage value VB input to the power supply voltage input terminal BATT, and the current measurement unit of each of the IPDs 131 and 132 input to the detection current input terminals SI1 and SI2. The electric power supplied to the load 3 by each of the electric wires 51 and 52 is calculated from the current detection signals I1 and I2 from b.

  Then, control is performed to adjust the duty ratio of the drive signals DR1 and DR2 of the semiconductor switching element a output from the output terminals OUT1 and OUT2 to the corresponding IPDs 131 and 132 so that the calculated powers of the wires 51 and 52 match. I do.

  That is, the control unit 11 is a reference value of the supplied power to the load 3 calculated from the passing current detected by the current measuring unit b of each IPD 131 and 132 and the voltage of the power supply B and the supplied power set in advance. Control is performed to adjust the duty ratio of the semiconductor switching element a of the corresponding IPDs 131 and 132 based on the comparison with the design value.

  FIG. 2 is a block diagram schematically showing a process performed inside the control unit 11. As shown in FIG. The control unit 11 executes a program stored in a memory (not shown) to detect the power supply voltage detection unit 111, the input determination control unit 112, the PWM_DUTY ratio control units 113a and 113b, the current detection units 114a and 114b, and the duty ratio detection. The functions of the units 115a and 115b, the power data calculation units 116a and 116b, and the duty ratio correction value calculation units 117a and 117b are realized.

  The power supply voltage detection unit 111 detects the terminal voltage of the power supply B (hereinafter referred to as “power supply voltage”) from the voltage value VB input to the power supply voltage input terminal BATT and the voltage division ratio of the voltage dividing resistors R1 and R2. And outputting a power supply voltage data signal indicating the value of the detected power supply voltage. The input determination control unit 112 determines the on / off state of the input switch SW based on the switch signal S input to the input terminal IN, and outputs the SW input signal when the input switch SW is on.

  The PWM_DUTY ratio control units 113a and 113b (corresponding to the PWM control units in the claims) are provided corresponding to the IPDs 131 and 132 of the electric wires 51 and 52, respectively. While the SW input signal from the input determination control unit 112 is being input, each of the PWM_DUTY ratio control units 113a and 113b outputs the drive signals DR1 and DR2 to the output terminals OUT1 and OUT2.

  The duty ratio of each of the drive signals DR1 and DR2 (the ratio of the on-duty period in the present embodiment) is set to 100% in the case of DC drive and less than 100% in the case of PWM drive. The duty ratio is set to an initial value according to the drive content of the load 3 immediately after the input switch SW is turned on, and thereafter corrected to a duty ratio correction value described later calculated by the duty ratio correction value calculation units 117a and 117b. Ru.

  The respective current detection units 114a and 114b and the respective duty ratio detection units 115a and 115b use the current detection signals I1 and I2 input to the detection current input terminals SI1 and SI2, respectively, to measure the current in the corresponding IPDs 131 and 132. Detects the passing current of each of the electric wires 51 and 52 to be detected and its duty ratio, and outputs a current data signal indicating the detection result and a DUTY ratio signal.

  FIG. 3 is a timing chart showing a procedure when each of the current detection units 114a and 114b and each of the duty ratio detection units 115a and 115b detect the passing current of each of the electric wires 51 and 52 and the duty ratio thereof. When the SW input signal S1 from the input determination control unit 112 shown in the upper part of FIG. 3 is switched from off to on, power from the power supply B is supplied to the load 3 via the IPDs 132 and 132 which are on / off driven by the drive signals DR1 and DR2. Supplied.

  Then, as shown in the middle part of FIG. 3, the current detection signals I1 and I2 corresponding to the passing currents of the wires 51 and 52 measured by the current measurement unit b of the IPDs 131 and 132 are input to the detection current input terminals SI1 and SI2. Be done. The current detection units 114a and 114b and the duty ratio detection units 115a and 115b sample the current detection signals I1 and I2 of the detection current input terminals SI1 and SI2 at the sample timing shown in the lower part of FIG.

  The current detection units 114a and 114b use the average value of sampling values of continuous sections (on sections) in which the level from the rise to the fall of the current detection signals I1 and I2 is not 0 as the passing current of the electric wires 51 and 52. To detect. Each of the DUTY ratio detection units 115a and 115b specifies the on section and the off section of the passing current of each wire 51 and 52 in the current detection signals I1 and I2 from the rising and falling timings of the current detection signals I1 and I2, From the identified on section and off section, the on / off cycle or duty ratio of the passing current of each wire 51, 52 is detected.

  Each of the duty ratio detectors 115a and 115b detects the duty ratio of the drive signals DR1 and DR2 set by the PWM_DUTY ratio controllers 113a and 113b as the on / off duty ratio of the passing current of each wire 51 or 52. Good.

  Power data calculation units 116a and 116b shown in FIG. 2 are a power supply voltage data signal from power supply voltage detection unit 111, current data signals from current detection units 114a and 114b, and duty ratio detection units 115a and 115b, and a duty ratio signal. Then, the actual power value (actual power supply value = effective value) supplied to the load 3 per unit time via the corresponding electric wires 51 and 52 is calculated.

  Specifically, each of the power data calculation units 116a and 116b (corresponding to the wire power calculation unit in the claims) is a passing current of the corresponding wires 51 and 52 indicated by the current data signal and the duty ratio signal and the duty ratio thereof. The current time product is determined by multiplying the current time product, and this is multiplied by the power supply voltage indicated by the power supply voltage data signal to calculate the actual supplied power value per unit time for the load 3 of each of the electric wires 51 and 52. Then, each of the power data calculation units 116a and 116b outputs a power data signal indicating the calculated actual supplied power value.

  The respective duty ratio correction value calculation units 117a and 117b calculate duty ratio correction values (correction values for duty ratio of PWM control) of the drive signals DR1 and DR2, and output a corrected duty ratio signal indicating the calculated correction values.

  The duty ratio correction values of the drive signals DR1 and DR2 represent the actual supplied power per unit time to the load 3 of each of the wires 51 and 52 indicated by the power data signal from each of the power data calculation units 116a and 116b. And the target power value (design value) of the supplied power per unit time corresponding to.

  The design value is determined according to the power supply voltage of the power supply B detected by the power supply voltage detection unit 111. For example, the load 3 is a vehicle valve (rated voltage 12 V, power consumption 60 W), and each PWM / DC control / cut-off determination unit 113 a, 113 b DC-drives the semiconductor switching element a of the corresponding IPD 131, 132 I assume. In this case, a current of 2.5 A flows through each of the electric wires 51 and 52.

  In this state, for example, assuming that the power supply voltage of the power supply B detected by the power supply voltage detection unit 111 is 13.5 V, the current flowing through the electric wires 51 and 52 is 2.5 A × (13.5 V / 12 V) ^ It becomes 0.5 = 2.65A.

  Therefore, the design value when the power supply voltage of the power supply B is 13.5 V is 13.5 V × 2.65 A = 35.8 W multiplied by the current flowing through each of the electric wires 51 and 52 at that time. The design value may be calculated using this formula every time the power supply voltage detection unit 111 detects the power supply voltage of the power supply B, and control is performed each time the power supply voltage detection unit 111 detects the power supply voltage of the power supply B. It may be read from a table stored in the internal memory (not shown) of the unit 11 in association with the power supply voltage of the power supply B.

  Then, each duty ratio correction value calculation unit 117a, 117b is such that the actual supplied power value per unit time to the load 3 of each wire 51, 52 indicated by the power data signal from each power data calculation unit 116a, 116b is When it is higher than the design value, the duty ratio of the drive signals DR1 and DR2 is calculated to match the actual supply power value indicated by the power data signal to the design value.

  For example, the current detection unit 114a detects that the passing current of the electric wire 51 measured by the current measurement unit b of the IPD 131 is 3.0 A, and based on this, the power data calculation unit 116a applies the load 3 to the electric wire 51. It is assumed that the actual supplied power value per unit time is calculated as 13.5 V × 3.0 A = 40.5 W.

  Further, the current detection unit 114b detects that the passing current of the electric wire 52 measured by the current measurement unit b of the IPD 132 is 2.5 A, and based on this, the power data calculation unit 116b applies the load 3 to the electric wire 52. It is assumed that the actual supplied power value per unit time is calculated as 13.5 V × 2.5 A = 35.8 W.

  In this case, the actual supplied power value per unit time for load 3 of wire 51 calculated by power data calculation unit 116a is higher than the design value, and per unit time for load 3 of wire 52 calculated by power data calculation unit 116b. The actual power supply value is equal to the design value.

  Therefore, the duty ratio correction value calculation unit 117a drives the drive signal so that the actual supplied power value per unit time for the load 3 of the wire 51 indicated by the power data signal from the power data calculation unit 116a matches the above-described design value. A duty ratio correction value of DR1 is calculated, and a corrected DUTY ratio signal indicating the calculated correction value is output.

  Specifically, the drive signal DR1 is calculated so that the actual supplied power value per unit time for the load 3 of the electric wire 51 calculated by the power data calculation unit 116a is reduced from the current 40.5 W to 35.8 W which is a design value. Calculate the duty ratio correction value of.

  In this case, the duty ratio correction value is obtained by dividing the target design value (35.8 W) by the current actual supplied power value (40.5 W) calculated by the power data calculation unit 116 a (35.8 / 40.5), can be calculated (duty ratio correction value = 88.4%).

  The PWM_DUTY ratio control unit 113a outputs the drive signal to the output terminal OUT1 when the corrected DUTY ratio signal from the duty ratio correction value calculation unit 117a is input while the drive signal DR1 is output to the output terminal OUT1. The duty ratio of DR1 is corrected to the duty ratio correction value of the drive signal DR1 indicated by the corrected DUTY ratio signal. Therefore, the operating state of the semiconductor switching element a of the IPD 131 changes from DC drive to PWM drive with a duty ratio of 88.4%.

  On the other hand, since the actual supplied power value per unit time for load 3 of wire 52 calculated by power data calculation unit 116 b is equal to the design value, duty ratio correction value calculation unit 117 b calculates duty ratio correction value of drive signal DR 1 of 100. Calculated as% (no correction), and output a corrected DUTY ratio signal indicating the calculated correction value. Therefore, the semiconductor switching element a of the IPD 132 continues DC driving.

  The example in the case where the PWM_DUTY ratio control units 113a and 113b drive the semiconductor switching elements a of the corresponding IPDs 131 and 132 has been described above.

  Next, an example in which the PWM_DUTY ratio control units 113a and 113b perform the PWM driving on the semiconductor switching elements a of the corresponding IPDs 131 and 132 will be described.

  For example, it is assumed that the respective semiconductor switching elements a of the IPDs 131 and 132 corresponding to the respective PWM_DUTY ratio control units 113a and 113b are PWM driven with a 50% duty ratio. In this case, assuming that the power supply voltage of the power supply B detected by the power supply voltage detection unit 111 is 13.5 V, 2.5A × (2.5 × A) for the electric wires 51 and 52 in the ON section of the semiconductor switching element a A current of 13.5 V / 12 V) ^ 0.5 = 2.65 A flows.

  Therefore, when the power supply voltage of the power supply B is 13.5 V, the design value at the time of PWM drive of 50% duty ratio is 50 of the design value (13.5 V × 2.65 A = 35.8 W) at the time of DC drive. It becomes 17.9 W of%.

  In this state, for example, the current detection unit 114a detects that the passing current of the electric wire 51 measured by the current measurement unit b of the IPD 131 in the ON section of the semiconductor switching element a is 3.0 A, and based on this It is assumed that the data calculation unit 116 a calculates the actual supplied power value per unit time for the load 3 of the electric wire 51 as 13.5 V × 3.0 A × 50% = 20.25 W.

  Further, the current detection unit 114b detects that the passing current of the electric wire 52 measured by the current measurement unit b of the IPD 132 is 2.5 A in the ON period of the semiconductor switching element a, and based on this, the power data calculation unit 116b However, it is assumed that the actual power supply value per unit time for the load 3 of the wire 52 is calculated as 13.5 V × 2.5 A × 50% = 17.9 W.

  Also in this case, since the duty ratio correction value calculation unit 117a calculates the actual supply power value per unit time for the load 3 of the wire 51 calculated by the power data calculation unit 116a is higher than the design value, the actual supply power value is the current. The duty ratio correction value (17.9 / 20.25 = 88.4%) of the drive signal DR1 is calculated so as to decrease from 20.25 W to 17.9 W which is a design value.

  On the other hand, since the actual supplied power value per unit time for load 3 of wire 52 calculated by power data calculation unit 116 b is equal to the design value, duty ratio correction value calculation unit 117 b calculates the duty ratio correction value of drive signal DR 1 as 100. Calculated as% (no correction), and output a corrected DUTY ratio signal indicating the calculated correction value. Therefore, the semiconductor switching element a of the IPD 132 continues the PWM driving with the 50% duty ratio.

  The frequency of the drive signals DR1 and DR2 at the time of PWM driving the semiconductor switching elements a of the IPDs 131 and 132 can be, for example, 100 Hz.

  As apparent from the above description, in the power supply control device 1 of this embodiment, the duty ratio determination unit in the claims includes the PWM_DUTY ratio control units 113a and 113b and the duty ratio correction value calculation unit 117a of the control unit 11. And 117b.

  Next, regarding the operation (action) performed in the power supply control device 1 having the above-described configuration, the operation related to the process performed by the control unit 11 will be extracted and described with reference to the flowchart in FIG. 4. In the power supply control device 1, the operation shown in the flowchart of FIG. 4 is repeatedly performed at predetermined intervals.

  First, from the signal level of the switch signal S, it is confirmed whether the input switch SW is on (step S1). If the input switch SW is not on (NO in step S1), the function of controlling the power supply to the load 3 is stopped by driving the semiconductor switching element a of the IPDs 131 and 132 (step S3). Then, after stopping the output of the drive signals DR1 and DR2 by the PWM_DUTY ratio control units 113a and 113b and turning off the IPDs 131 and 132 (step S5), a series of operations are ended.

  On the other hand, when the input switch SW is on (YES in step S1), it is checked whether the voltage value VB is input to the power supply voltage input terminal BATT (step S7). If it is not input (NO in step S7), the process proceeds to step S25 described later, and if it is input (YES in step S7), the power supply voltage of power supply B is determined by power supply voltage detection unit 111 based on input voltage value VB. (0 to 20 V) is detected (step S9). The detected power supply voltage is notified to the power data calculation units 116a and 116b by the power supply voltage data signal.

  Subsequently, it is checked whether or not the current detection units 114a and 114b detect the ON sections of the current detection signals I1 and I2 (whether the current value has been detected) (step S11). If the on sections of the current detection signals I1 and I2 are not detected (NO in step S11), the process proceeds to step S25. If it is detected (YES in step S11), the current detection units 114a and 114b detect the passing currents of the wires 51 and 52, and generate corresponding current data signals (step S13).

  Subsequently, it is checked whether the duty ratio detection unit 115 detects the duty ratio of the current detection signal I (whether the duty ratio has been detected) (step S15). When the duty ratio of the current detection signals I1 and I2 is not detected (NO in step S15), the process proceeds to step S25. If detected (YES in step S15), the power data calculators 116a and 116b calculate power data indicating the actual supplied power value supplied to the load 3 per unit time via the electric wires 51 and 52. (Step S17).

  Then, it is confirmed whether or not the actual supplied power value supplied to the load 3 per unit time via the electric wires 51 and 52 indicated by the calculated power data (the actual supplied power value of the load 3) is larger than the design value. (Step S19). If not larger than the design value (NO in step S19), the process proceeds to step S25, assuming that the actual supply power value is equal to the design value.

  In addition, when it is larger than the design value (YES in step S19), the corresponding semiconductor of IPD 131, 132 for making the actual power supply value per unit time for load 3 of the corresponding electric wire 51, 52 match the design value. The correction value of the duty ratio of the drive signals DR1 and DR2 output to the switching element a is calculated by the corresponding duty ratio correction value calculation units 117a and 117b (step S21).

  The duty ratio in the DC drive or PWM drive of the semiconductor switching element a of the IPDs 131 and 132 provided in the wires 51 and 52 whose actual supplied power value is larger than the design value corresponds to the corresponding duty ratio correction value calculation unit 117a and 117b. After correcting with the correction value calculated by the above, and after the semiconductor switching elements a of the IPDs 131 and 132 corresponding to the PWM_DUTY ratio control units 113a and 113b are DC driven or PWM driven with the corrected duty ratio (step S23), a series of operations Finish.

  In step S25, the IPDs 131 and 132 of the electric wires 51 and 52 have the same duty ratio as before so that the load 3 is supplied with electric power equal to the design value as before to the load 3 via the electric wires 51 and 52. Drive by. Here, assuming that the IPDs 131 and 132 of the electric wires 51 and 52 have been DC driven, the semiconductor switching elements a are DC driven from the respective PWM_DUTY ratio controllers 113a and 113b to the semiconductor switching elements a of the IPDs 131 and 132. Drive signals DR1 and R2 are output. Thereafter, the series of operations is ended.

  In the power supply control device 1 of the present embodiment that performs the above-described operation, when the semiconductor switching elements a of the IPDs 131 and 132 provided respectively in the electric wires 51 and 52 connected in parallel to the power supply B are turned off In order to cut off the power supplied to the load 3 via the semiconductor device, the current measuring portions b of the IPDs 131 and 132 measure the passing currents respectively flowing through the semiconductor switching elements a on the electric wires 51 and 52. Then, from the voltage value VB input to the power supply voltage input terminal BATT and the measurement current, the power data calculation units 116a and 116b calculate the power supplied to the load 3 by the wires 51 and 52.

  In addition, the duty ratio correction value at the time of performing PWM control of the driving of the semiconductor switching element a of the IPDs 131 and 132 on the electric wires 51 and 52 for matching the power supplied to the load 3 by the respective electric wires 51 and 52 The ratio correction value calculation units 117a and 117b calculate the ratio correction value. Then, with the duty ratio corrected by the calculated correction value, the PWM_DUTY ratio control units 113a and 113b perform PWM control on the driving of the semiconductor switching elements a of the corresponding IPDs 131 and 132.

  Therefore, by performing PWM control on the semiconductor switching elements a of the IPDs 131 and 132 with the corrected duty ratio, the on resistance of the semiconductor switching elements a and the circuit resistances of the internal circuits have variations among the IPDs 131 and 132, Even if there are variations in the wiring resistance of the wires 51, 52 due to the unification of the route lengths and wire types of the wires 51, 52, and the layout of the wiring, the power supplied to the load 3 via the wires 51, 52 is made to match be able to.

  In the embodiment described above, the parallel circuit 5 for supplying the power of the power source B to the load 3 has been described as being constituted by the two electric wires 51 and 52 having the IPDs 131 and 132 interposed therebetween. However, the present invention is also applicable to the case where a parallel circuit is configured by three or more wires each having an IPD interposed therebetween.

  In addition, when the actual supplied power value of each wire is different, in the above-described embodiment, the actual supplied power value of each wire is made to match the design value. However, for example, when the actual supply power value of the other wire is made equal to the lower power value or the higher power value of the actual supply power values of each wire, or when there are three or more wires, intermediate power The values may be matched with the actual power supply values of other wires.

  Furthermore, although IPD 131,132 was used in embodiment mentioned above, this invention is applicable also when controlling electric power supply to the load 3 using semiconductor switching elements other than IPD 131,132, such as a power semiconductor switch. .

  In the embodiment described above, the case where the power of the power supply B is supplied to the common load 3 by the respective wires 51 and 52 of the parallel circuit 5 has been described, but in the present invention, the plurality of wires connected in parallel to the power supply individually The present invention is also applicable to the case where power is supplied to the respective loads.

  The present invention is extremely useful when the power supplied to the load from the power supply to the load is cut off by turning off the semiconductor switching elements respectively provided to the plurality of wires connected in parallel to the power supply of the vehicle.

1 Power supply control device (vehicle power supply control device)
DESCRIPTION OF SYMBOLS 3 load 5 parallel circuit 11 control part 51, 52 electric wire 111 power supply voltage detection part 112 input determination control part 113a, 113b PWM_DUTY ratio control part (duty ratio determination part, PWM control part)
114a, 114b current detection unit 115a, 115b duty ratio detection unit 116a, 116b power data calculation unit (electric wire power calculation unit)
117a, 117b Duty ratio correction value calculation unit (duty ratio determination unit)
131, 132 Intelligent Power Device (IPD)
a Semiconductor switching element b Current measurement unit B Power supply BATT Supply voltage input terminal DR1, DR2 Drive signal I1, I2 Current detection signal IN input terminal OUT1, OUT2 output terminal S switch signal S1 SW input signal SI1, SI2 detected current input terminal SW input switch

Claims (1)

By turning off the semiconductor switching element provided in each of a plurality of wires connected in parallel to the power supply of the vehicle, Te power controller odor vehicle to cut off power supplied to the load via the respective wires from the power supply,
A power supply voltage detection unit that detects a voltage of the power supply;
A current measuring unit for measuring a passing current through pre Symbol of the semiconductor switching devices, respectively,
And wire power calculating section for calculating the detected voltage Toka et of the the measured current of the current measuring unit supply voltage detection unit, before Symbol each actual supply electric power value of the power supplied to the load by the electric wires respectively,
Each of the electric wires has a design value of a target supplied power per unit time from the electric wire to the load, which is determined based on a passing current serving as a reference of each of the semiconductor switching elements determined from the detected voltage and the resistance of the load. and the duty ratio determining unit for determining said to match each actual supply electric power value to the load, the duty ratio of the PWM control before Symbol the semiconductor switching devices of each wire respectively from,
A PWM control unit that performs PWM control of each of the semiconductor switching elements according to the duty ratio determined by the duty ratio determination unit corresponding to each of the semiconductor switching elements;
A power supply control device for a vehicle, comprising:

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