JP2019118165A - Controller and control method of power conversion device - Google Patents

Abstract

To improve responsiveness of a power conversion device.SOLUTION: A controller according to an embodiment comprises a switching part, a detection part, a calculation part, and a generation part. The switching part switches between a first mode of outputting current via a parasitic diode by turning off a switching element on an output side of a power conversion device, and a second mode of outputting current via the switching element by turning on the switching element. The detection part detects a drop voltage of the parasitic diode in a state where the switching element is turned off. The calculation part calculates a correction signal for correcting a control signal of the power conversion device on the basis of the drop voltage. The generation part generates the control signal corrected by using the correction signal when being switched from one mode to another mode by the switching part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device and a control method of a power conversion device.

  BACKGROUND A control device is conventionally known that controls a voltage conversion device that boosts and lowers the voltage of a power supply (for example, a lead battery) mounted on a vehicle and outputs the voltage to an inverter (see, for example, Patent Document 1).

JP, 2015-202018, A

  However, in the prior art, when switching the current path of the voltage conversion device, the output current of the voltage conversion device oscillates due to the influence of component variation of the parasitic diode used in the voltage conversion device, and the response of the voltage conversion device There was a risk of decline.

  The present invention is made in view of the above, and an object of the present invention is to provide a control device and a control method of a power conversion device capable of improving the responsiveness of the power conversion device.

  The control device according to the embodiment includes a switching unit, a detection unit, a calculation unit, and a generation unit. The switching unit turns off the switching element on the output side of the power converter and outputs a current through a parasitic diode, and a second mode turning on the switching element and outputting a current through the switching element Switch. The detection unit detects the voltage drop of the parasitic diode when the switching element is in the off state. The calculation unit calculates a correction signal for correcting the control signal of the power converter based on the voltage drop. The generation unit generates the corrected control signal using the correction signal when the switching unit switches from one mode to the other mode.

  According to the present invention, the responsiveness of the power conversion device can be improved.

FIG. 1 is a block diagram of a power supply system. FIG. 2 is a diagram showing a configuration example of a DCDC converter. FIG. 3 is a block diagram of a converter control device. FIG. 4A is a diagram showing a first mode at the time of boosting. FIG. 4B is a diagram showing a second mode at the time of boosting. FIG. 5 is a timing chart showing the timing of correction. FIG. 6 is a diagram showing the output current after correction. FIG. 7 is a flowchart showing a processing procedure executed by the converter control device.

  Hereinafter, the control device and the control method of the power conversion device according to the embodiment will be described in detail with reference to the attached drawings. The present invention is not limited by this embodiment.

  First, a power supply system S including a control device according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram of a power supply system S according to an embodiment. The power supply system S includes a vehicle power supply device 1, a lead battery 3, an electric load 4, a lithium ion battery (LIB) 5, a generator 6, and a starter 7.

  The lead battery 3 is a secondary battery using lead as an electrode. The lead battery 3 is a main power source of electric devices mounted on a vehicle. The electrical load 4 is an electrical device provided to the vehicle. For example, a navigation device, an audio, an air conditioner, etc. may be mentioned as the electrical load 4. Alternatively, for example, the electric load 4 may be a vehicle control device that performs vehicle control such as PCS (Pre-crash Safety System) or AEB (Advanced Emergency Braking System).

  LIB5 is a storage battery that stores electric charge. LIB 5 is an auxiliary power supply for the lead battery 3. The auxiliary power supply may be any storage device, and may be a capacitor or another secondary battery instead of LIB5.

  The generator 6 is a device that generates power using a rotation of an engine (not shown) as a power source. In addition, the generator 6 generates regenerative electric power by the regenerative brake when the vehicle decelerates. For example, the generator 6 is an alternator or a generator.

  The generator 6 generates electric power, for example, in response to an instruction from an engine control device (not shown). The power generated by the generator 6 is supplied to, for example, the lead battery 3 or LIB 5. Thereby, the lead battery 3 and LIB 5 are charged.

  The starter 7 is a starting device that includes an electric motor and starts the engine. Here, although the power supply system S includes the starter 7 and the generator 6, the power supply system S may include an integrated starter generator (ISG) instead of the starter 7 and the generator 6.

  The vehicle power supply device 1 controls the entire power supply system S. The vehicle power supply device 1 includes a first switch unit 11, a second switch unit 12, a power control unit 13, a DCDC converter 14, and a converter control unit 15.

  The first switch unit 11 and the second switch unit 12 are switches (relays) that control short circuit and open circuit. The first switch unit 11 is connected between the lead battery 3 and the generator 6 and between the lead battery 3 and the starter 7.

  The second switch unit 12 is connected between the LIB 5 and the generator 6 and between the LIB 5 and the starter 7. One ends of the first switch unit 11 and the second switch unit 12 are connected to each other, and the power control device 13 controls opening / closing (on / off). The number and arrangement of the first switch unit 11 and the second switch unit 12 shown in FIG. 1 are an example, and the present invention is not limited to this. For example, the vehicle power supply device 1 includes three or more switch units. It is also good.

  The power supply control device 13 includes, for example, a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input / output port, and various circuits. The power supply control device 13 executes the program stored in the ROM by the CPU using the RAM as a work area, thereby executing the switch control unit 13a, the drive signal generation unit 13b, and the vehicle state acquisition unit 13c. It functions as the charge state acquisition unit 13d.

  The switch control unit 13a controls the open / close state of the first switch unit 11 and the second switch unit 12 with reference to the charge state of the lead battery 3 and the LIB 5, the consumption current of the electric load 4, the state of the vehicle, and the like. The charge state acquisition unit 13d acquires the charge states of the lead battery 3 and LIB5.

  The drive signal generation unit 13 b controls the drive state of the DCDC converter 14 according to the charge state of the lead battery 3 and the LIB 5, the consumption current of the electric load 4, the state of the vehicle, and the like. Specifically, the drive signal generation unit 13 b generates a drive signal according to the target output current of the DCDC converter 14, and outputs the drive signal to the converter control device 15.

  The vehicle state acquisition unit 13c acquires the state of the vehicle from an onboard sensor (not shown). The state of the vehicle includes the traveling state of the vehicle and the driving state of the engine. The traveling state of the vehicle refers to a state such as during traveling or deceleration of the vehicle. The vehicle state acquisition unit 13c determines, for example, a state during traveling or deceleration of the vehicle based on a signal output from a vehicle speed sensor among the on-vehicle sensors.

  The driving state of the engine refers to a state such as at the time of initial start of the engine and at the time of restarting (resting) from the idling stop. The first start of the engine is when the driver gets into the vehicle and operates the key or button that is the start switch (not shown) to start the engine for the first time. When restarting from an idling stop (when returning), for example, the engine is temporarily stopped while waiting for a signal (idling stop), and then the driver cancels the start operation, for example, the depression of the brake pedal It is time to restart the engine.

  The DCDC converter 14 is a voltage conversion device that converts (steps down or boosts) a DC voltage (input voltage) into another DC voltage (output voltage). The DCDC converter 14 can convert a DC voltage into another DC voltage by operating based on a control signal output from the converter control device 15.

  The DCDC converter 14 is connected between the lead battery 3 and the LIB 5 and between the electrical load 4 and the LIB 5. Further, one end of the DCDC converter 14 is connected to the first switch unit 11, and the other end is connected to the second switch unit 12.

  For example, when supplying power from the LIB 5 to the lead battery 3, the DCDC converter 14 boosts the voltage of the LIB 5 and supplies it to the lead battery 3. When supplying power from the LIB 5 to the electrical load 4, the DCDC converter 14 steps up or down the voltage of the LIB 5 and supplies it to the electrical load 4.

  As shown in FIG. 2, the DCDC converter 14 is a so-called H-bridge converter, and includes switching elements Q1 to Q4, parasitic diodes D1 to D4 provided in the switching elements Q1 to Q4, and an inductor L. FIG. 2 is a view showing an example of the configuration of the DC-DC converter 14.

  The switching elements Q1 to Q4 are, for example, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The switching elements Q1 to Q4 may be other charge effect transistors such as IGBTs (Insulated Gate Bipolar Transistors). Parasitic diodes D1 to D4 are connected between sources and drains of the switching elements Q1 to Q4, respectively.

  The DCDC converter 14 can boost or step down in two directions, but in the following, the input voltage input from the left side (the switching element Q1 side) in FIG. The case of outputting from the switching element Q3) will be described as an example.

  The DCDC converter 14 is provided with a voltage sensor 20 that measures the voltage at both ends of the parasitic diode D3 on the output side. A signal related to the voltage measured by the voltage sensor 20 is transmitted to a detection unit 15a described later.

  Next, converter control device 15 will be described with reference to FIG. FIG. 3 is a block diagram of converter control device 15. Converter control device 15 is a control device that controls DC-DC converter 14. Converter control device 15 generates a control signal based on a drive signal input from power supply control device 13 and outputs the control signal to DCDC converter 14 to control DCDC converter 14.

  The converter control device 15 includes, for example, a microcomputer having a CPU, a ROM, a RAM, an input / output port and the like, and various circuits. Then, converter control device 15 functions as detection unit 15a, switching unit 15b, calculation unit 15c, and generation unit 15d by the CPU executing a program stored in ROM using RAM as a work area. Do.

  The detection unit 15a detects the voltage drop of the parasitic diode D3 when the switching element Q3 on the output side is off. The detection unit 15 a detects the voltage drop based on the signal from the voltage sensor 20. Specifically, at the time of the initial check performed when the start switch (not shown) is changed from off to on, the detection unit 15a puts the switching element Q3 into the off state, flows a current to the parasitic diode D3, and drops. Detect the voltage. That is, the detection unit 15a detects the voltage drop and updates the voltage drop each time the initial check is performed.

  The switching unit 15 b switches the output mode of the DCDC converter 14 according to the output current of the DCDC converter 14. Here, the details of the output mode will be described using FIGS. 4A and 4B. FIG. 4A is a diagram showing a first mode at the time of boosting. FIG. 4B is a diagram showing a second mode at the time of boosting.

  The switching unit 15b switches on / off of the switching element Q4 in a state where the switching element Q1 of the DC-DC converter 14 is on and the switching element Q2 and the switching element Q3 are off in the first mode.

  Thereby, energy can be stored in the inductor L by electromagnetic induction, and the input voltage can be boosted to a desired output voltage. The output voltage boosted in the first mode is output via the parasitic diode D3. As described above, the first mode is a mode in which current is output from the DCDC converter 14 through the parasitic diode D3 on the output side.

  In the first mode, since the switching element Q3 is turned off, it is possible to prevent the backflow of current from the switching element Q3 side to the switching element Q1 side. That is, when the boosted voltage is lower than the voltage on the output side (switching element Q3 side), it is possible to prevent the current from flowing back from the output side to the input side.

  However, when the switching element Q3 is kept off, a large current flows in the parasitic diode D3 when the output current becomes large. As a result, the parasitic diode D3 may generate heat and burn.

  Therefore, the switching unit 15b switches the output mode of the DCDC converter 14 from the first mode to the second mode when the output current of the DCDC converter 14 becomes equal to or higher than the switching point Tp. The switching point Tp corresponds to, for example, the allowable current of the parasitic diode D3.

  The switching unit 15b switches on / off of the switching element Q3 and the switching element Q4 in the second mode with the switching element Q1 on the input side turned on and the switching element Q2 turned off. As described above, the second mode is a mode in which current is output from the DCDC converter 14 via the switching element Q3 on the output side.

  In the second mode, since the current which is equal to or higher than the switching point Tp does not flow in the parasitic diode D3, it is possible to prevent the burnout due to the heat generation of the parasitic diode D3 and to prolong the life of the parasitic diode D3.

  As described above, in the first mode, current is output in the current path (hereinafter, also described as a first path) through the parasitic diode D3, whereas in the second mode, current through the switching element Q3 is output. A current is output along a path (hereinafter also referred to as a second path). Therefore, in the second mode, the heat generation of the parasitic diode D3 can be suppressed, and the burnout of the parasitic diode D3 can be suppressed.

  The switching unit 15 b switches the output mode of the DCDC converter 14 from the second mode to the first mode when the output current of the DCDC converter 14 becomes smaller than the switching point Tp.

  The switching unit 15 b turns on the switch SW when switching the output mode. Thereby, the correction signal generated by the calculation unit 15c described later is input to the generation unit 15d.

  Returning to FIG. 3, the calculation unit 15 c includes a correction signal generation unit 153 and a switch SW. The correction signal generation unit 153 calculates a correction signal (Duty ratio) which is a correction value for correcting the control signal based on the voltage drop detected by the detection unit 15a. When the DCDC converter 14 boosts the voltage, the correction signal generation unit 153 calculates a correction signal according to equation (1) and generates a correction signal.

  Correction signal = ((output voltage-voltage drop)-input voltage) / (output voltage-voltage drop) · · · (1)

  When the DCDC converter 14 steps down the voltage, the correction signal generation unit 153 calculates the correction signal by equation (2).

  Correction signal = (output voltage-voltage drop) / input voltage (2)

  One end of the switch SW is connected to the correction signal generation unit 153, and the other end is connected to the generation unit 15d. The switch SW is controlled to be on / off by the switching unit 15 b. The switch SW may be included in the switching unit 15b.

  The switch SW is turned on by the control of the switching unit 15b when the switching unit 15b switches the output mode, and then turned off after a certain period has elapsed. That is, the switch SW is turned on only for a certain period when the output mode is switched from the first mode to the second mode and from the second mode to the first mode.

  The fixed period is one cycle of feedback control performed by the generation unit 15 d. Thus, the correction signal is input to the integrator 156 only at the timing when the output mode is switched.

  The generation unit 15 d includes a proportional operation unit 155, an integration operation unit 154, an integrator 156, and an adder 157.

  The proportional operation unit 155 calculates a proportional operation amount proportional to the difference between the drive signal and the output signal of the DCDC converter 14. For example, when the DCDC converter 14 is current-controlled, the proportional operation unit 155 calculates a proportional operation amount proportional to the difference between the drive signal which is the target output current and the output current of the DCDC converter 14.

  The integration operation unit 154 obtains an operation value corresponding to the difference between the drive signal and the output current of the DCDC converter 14 and the integration gain, and outputs the operation value to the integrator 156.

  The integrator 156 integrates the operation value calculated by the integration operation unit 154 to calculate an integral operation amount. When the switching unit 15b switches the output mode, the integrator 156 performs correction by adding or subtracting a correction signal to the calculated value. Specifically, the integrator 156 subtracts the correction signal from the operation value when switching from the first mode to the second mode, and changes the correction signal to the operation value when switching from the second mode to the first mode Add The integrator 156 integrates the operation value after correction when the switching unit 15 b switches the output mode. In this manner, the calculated value is corrected by the correction signal.

  After the correction signal is added or subtracted from the calculated value, the corrected calculated value is integrated by the integrator 156. Thereby, the effect of the subsequent correction can be maintained by the input of one correction signal. That is, when the calculation unit 15 c inputs one correction signal to the integration operation unit 154, it is possible to minimize the number of corrections of the operation value.

  The adder 157 adds the proportional operation amount calculated by the proportional operation unit 155 and the integral operation amount calculated by the integrator 156 to generate a control signal, and outputs the control signal to the DCDC converter 14. Thereby, the DCDC converter 14 outputs an output voltage according to the control signal. The control signal corresponds to the pulse width (Duty ratio) of the gate voltage that controls the on / off of each of the switching elements Q1 to Q4.

  As described above, when the output mode is switched, the generation unit 15 d generates a corrected control signal using the correction signal based on the voltage drop due to the parasitic diode D3.

  When the output mode of DCDC converter 14 is the first mode, a current flows through parasitic diode D3 in the first path, so the conduction loss is smaller than that in the second path by the resistance of parasitic diode D3. growing. That is, the first mode and the second mode have different conduction losses.

  Therefore, when the output mode is switched between the first mode and the second mode, the output current of the DCDC converter 14 fluctuates at the switching timing of the conduction path. For example, when the control signal is set such that the output voltage in the second mode is 16 V, in the first mode, the output voltage is 16 V in consideration of the conduction loss due to the parasitic diode D3. A drive signal (Duty ratio) in which the on ratio is higher than that in the second mode is set.

  In such a case, for example, when the first mode is switched to the second mode, the output current of the DC-DC converter 14 may oscillate due to the fluctuation of the voltage. In addition, there is a possibility that the output current of the DCDC converter 14 oscillates due to component variation of the parasitic diode D3 or the like. Further, the fluctuation of the voltage may cause overshoot or undershoot of the output current. Therefore, due to these influences, the responsiveness of the DCDC converter 14 may be reduced.

  The converter control device 15 according to the embodiment generates a control signal corrected using a correction signal for suppressing voltage fluctuation due to the parasitic diode D3 at the timing when the output mode is switched, and DCDC based on the generated control signal. The converter 14 is controlled. As a result, it is possible to improve the responsiveness of the DCDC converter 14.

  Next, the timing of correction by the converter control device 15 will be described using FIG. FIG. 5 is a timing chart showing the timing of correction.

  As shown in A of FIG. 5, the switching unit 15 b switches the output mode from the first mode to the second mode as shown in B of FIG. 5 at time t1 when the output current of the DCDC converter 14 is equal to or higher than the switching point Tp. .

  At this time, as shown in C of FIG. 5, the switching unit 15b turns on the switch SW only for a predetermined period from time t1 to time t2. As a result, since the correction signal generated based on the drop voltage is subtracted from the operation value, the control signal becomes smaller as shown in E of FIG. In D of FIG. 5, the correction signal in the case of subtracting the calculated value is indicated by a signal projecting downward (the control signal becomes smaller) on the basis of the state where the switch SW is off, and the calculated value is added. Is indicated by a signal projecting upward (the control signal becomes large).

  After that, as shown in A of FIG. 5, at time t3 when the output current becomes smaller than the switching point Tp, the switching unit 15b changes the output mode from the second mode to the first mode as shown in B of FIG. Switch.

  At this time, as shown in C of FIG. 5, the switch SW is turned on for a predetermined period from time t3 to time t4. As a result, since the correction signal generated based on the voltage drop is added to the operation value, the control signal becomes large as shown in E of FIG.

  As described above, converter control device 15 adds or subtracts the correction signal to the calculated value when the output mode is switched. Thereby, as shown to E of FIG. 5, the control signal of the 1st mode inputted into DCDC converter 14 can be made larger than the control signal of the 2nd mode.

  In other words, it is possible to fill in the difference between the conduction losses of the first path and the second path that occur when the output mode is switched. In addition, the generation of the control signal corrected by the correction signal based on the voltage drop can suppress the influence of component variations of the parasitic diode D3 and the like.

  Next, the output current in the DCDC converter 14 according to the embodiment will be described with reference to FIG. FIG. 6 is a diagram showing an output current in the DC-DC converter 14 according to the embodiment. As described above, the switching unit 15b switches the output mode of the DCDC converter 14 at time t11 when the output current of the DCDC converter 14 is equal to or higher than the switching point Tp and at time t12 when the output current becomes smaller than the switching point Tp.

  Then, the generation unit 15d generates a control signal corrected based on the voltage drop in accordance with the switching timing of the output mode. Thereby, when the output mode is switched, in particular, immediately after the switching of the output mode, it is possible to suppress the oscillation of the output current and improve the responsiveness of the DCDC converter 14 to the drive signal.

  Next, processing procedures executed by the converter control device 15 according to the embodiment will be described using FIG. 7. FIG. 7 is a flowchart showing a processing procedure executed by converter control device 15. The processing procedure is repeatedly executed by converter control device 15.

  The converter control device 15 detects the voltage drop of the parasitic diode D3 in the state where the switching element Q3 is off at the time of the initial check in which the start switch is changed from off to on (S10). Note that after the initial check is completed, the process of detecting the voltage drop is skipped and the next process is performed.

  Converter control device 15 determines whether or not the output mode of DCDC converter 14 is the first mode (S11). If the output mode of DCDC converter 14 is the first mode (S11: Yes), converter control device 15 determines whether the output current of DCDC converter 14 is smaller than switching point Tp (S12).

  If the output current is smaller than switching point Tp (S12: Yes), converter control device 15 calculates an operation value based on the drive signal (S13), generates a control signal (S14), and generates control A signal is output (S15).

  When the output current of the DC-DC converter 14 is equal to or higher than the switching point Tp (S12: No), the converter control device 15 calculates a correction signal based on the voltage drop (S16) and sets the output mode from the first mode to the first mode. Switch to 2 mode (S17). Converter control device 15 calculates an operation value obtained by subtracting the correction signal (S18), generates a control signal based on the operation value obtained by subtracting the correction signal (S14), and outputs the generated control signal (S15).

  When the output mode of DCDC converter 14 is the second mode (S11: No), converter control device 15 determines whether the output current of DCDC converter 14 is equal to or higher than switching point Tp (S19).

  When the output current is equal to or higher than the switching point (S19: Yes), converter control device 15 calculates an operation value based on the drive signal (S13), and generates a control signal based on the operation value (S14) , And outputs the generated control signal (S15).

  When the output current is smaller than switching point Tp (S19: No), converter control device 15 calculates the correction signal based on the voltage drop (S20), and switches the output mode from the second mode to the first mode. (S21). Converter control device 15 calculates an operation value obtained by adding the correction signal (S22), generates a control signal based on the operation value obtained by adding the correction signal (S14), and outputs the generated control signal (S15).

  Converter control device 15 detects a voltage drop of parasitic diode D3 when switching element Q3 on the output side of DCDC converter 14 is off, and calculates a correction signal for correcting the control signal based on the detected voltage drop. . Then, when the output mode of DCDC converter 14 is switched between the first mode and the second mode, converter control device 15 generates a control signal corrected by the correction signal.

  Thereby, when the output mode of DCDC converter 14 switches, the fluctuation of the voltage can be suppressed. In addition, when the output mode of the DCDC converter 14 is switched, it is possible to suppress oscillation of the output current of the DCDC converter 14 due to, for example, component fluctuations of the parasitic diode D3 or temperature change of the DCDC converter 14. In addition, the occurrence of overshoot or undershoot of the output current can be suppressed. Therefore, the responsiveness of the DCDC converter 14 can be improved.

  Converter control device 15 detects the voltage drop at the time of the initial check when the start switch is changed from off to on. Thereby, for example, it is possible to suppress the oscillation of the output current of the DCDC converter 14 due to the influence of the aged deterioration of the parasitic diode D3. Therefore, converter control device 15 can improve the responsiveness of DCDC converter 14.

  When the converter control device 15 newly detects the voltage drop, it calculates a correction signal based on the newly detected voltage drop. That is, when converter control device 15 newly detects a voltage drop and updates the voltage drop, it calculates a correction signal based on the updated voltage drop and corrects the control signal corrected based on the updated voltage drop. Generate

  Thus, converter control device 15 can control DCDC converter 14 with the control signal corrected based on the state of DCDC converter 14. Therefore, converter control device 15 can control DCDC converter 14 in response to, for example, the aged deterioration of parasitic diode D3, and can further improve the responsiveness of DCDC converter 14.

  The converter control device 15 according to the modification may detect the voltage drop after the initial check is completed. For example, the converter control device 15 according to the modification may detect the voltage drop when the vehicle is traveling or stopped and the switching element Q3 is in the off state.

  In addition, when switching element Q3 is in the off state, converter control device 15 according to the modification periodically detects the voltage drop, for example, after the state in which switching element Q3 is off continues for a predetermined time. It is also good. The predetermined time is a time set in advance, and a plurality of predetermined times may be set.

  Thus, the converter control device 15 according to the modification can improve the responsiveness of the DCDC converter 14 as in the above embodiment. Further, converter control device 15 according to the modification can detect, for example, a voltage drop in DCDC converter 14 whose temperature has become high after the vehicle is started, and DCDC converter 14 of DCDC converter 14 according to the state of DCDC converter 14. Responsiveness can be further improved.

  Also, the converter control device 15 according to the modification may detect the voltage drop immediately before the output mode switches from the first mode to the second mode. For example, the converter control device 15 according to the modification may detect the voltage drop when the output current becomes equal to or more than a predetermined current lower than the switching point Tp. The predetermined current is a current set in advance as a current that can be determined when the output current increases and becomes equal to or higher than the switching point Tp.

  Thereby, converter control device 15 according to the modification can generate a control signal corrected based on the voltage drop immediately before the output mode is switched from the first mode to the second mode, and according to the state of DCDC converter 14 Thus, the responsiveness of the DCDC converter 14 can be further improved.

  Moreover, the converter control apparatus 15 which concerns on a modification may correct | amend a drive signal or a control signal directly with a correction signal. Also by this, the converter control device 15 according to the modification can generate the control signal corrected based on the voltage drop.

  By the way, although the case where the converter control apparatus 15 controls the DCDC converter 14 used for the power supply system S for vehicles was demonstrated by embodiment mentioned above, it is not limited to this. That is, converter control device 15 can be applied as a control device for various DC-DC converters 14.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the invention are not limited to the specific details and representative embodiments represented and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Power supply apparatus for vehicles 14 DCDC converter 15 Converter control apparatus 15a Detection part 15b Switching part 15c Calculation part 15d Generation part Q Switching element D Parasitic diode S Power system Tp Switching point

Claims (6)

Switching is made between a first mode in which the switching element on the output side of the power conversion device is turned off to output current through a parasitic diode, and a second mode in which the switching element is turned on to output current through the switching element A switching unit,
A detection unit that detects a voltage drop of the parasitic diode when the switching element is off;
A calculation unit that calculates a correction signal for correcting the control signal of the power converter based on the voltage drop;
A control unit that generates a control signal corrected using the correction signal when the switching unit is switched from one mode to the other mode. The calculation unit
The control device according to claim 1, wherein when the voltage drop is newly detected, the correction signal is calculated based on the voltage drop newly detected. The detection unit is
The control device according to claim 1 or 2, wherein the voltage drop is detected when a start switch of a system in which the power conversion device is mounted is changed from off to on. The detection unit is
The control device according to claim 1, wherein the voltage drop is periodically detected. The detection unit is
The control device according to claim 1, wherein the voltage drop is detected immediately before switching from the first mode to the second mode. Switching is made between a first mode in which the switching element on the output side of the power conversion device is turned off to output current through a parasitic diode, and a second mode in which the switching element is turned on to output current through the switching element Switching process,
Detecting the voltage drop of the parasitic diode when the switching element is in the off state;
Calculating a correction signal for correcting the control signal of the power conversion device based on the voltage drop;
And a generation step of generating the control signal corrected using the correction signal when switching from one mode to the other mode in the switching step.

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