JP2011010519A - Dc/dc converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent effect on peripheral apparatuses by suppressing noise radiation from an input line.SOLUTION: A DC/DC converter 100 includes an input section, an output section, a smoothing capacitor C0, and an energization control section 10 having a plurality of switch elements, and performs power conversion by switching the plurality of switch elements. A first inductor L1 is in a relation, such that where a positive electrode side terminal of the input section is connected in parallel with the smoothing capacitor, with one end connected to the positive electrode side terminal of the input section and the other end connected to the positive electrode side terminal of the energization control section 10. A second inductor L2 is in a relation, such that where a negative electrode side terminal of the input section is connected in parallel with the smoothing capacitor with one end connected to the negative electrode side terminal of the input section and the other end connected to the negative electrode side terminal of the energization control section.

Description

  The present invention relates to a power converter, particularly a DC / DC converter, in an electric and electric assist system of an automobile.

  Generally, in the configuration of the electric power converter of the electric and electric assist system system of the automobile 1000, a power control unit (PCU: Power Control Unit) 500 and a battery 600 are arranged at a certain distance via a wiring 550. . The power control unit (PCU) 500 includes a noise filter 520 that receives an input electric signal from the battery 600 and a DC / DC converter 510 that converts the signal (FIGS. 16 and 17). ).

  The noise filter 520 is configured with a core-shared inductor having a noise radiation reduction function. Since the winding direction of the common core type inductor is wound so as to cancel each other's magnetism, the mutual inductance M of the common core type inductor is zero. Therefore, even if a main current is input to the noise filter 520, the magnetic storage effect does not occur, so the noise filter 520 does not have a magnetic storage function.

Further, DC / DC converter 510, a smoothing capacitor C0 of the input side of the noise filter 520 side, the inductor L having a magnetic storage function, two switch elements for energization control (here, IGBT: Insulated Gate Bipolar Transistor ) A capacitor C1 is provided between S1 and S2 and the output terminal (FIG. 17). Therefore, the noise radiation reduction function and the magnetic storage function are shared by the noise filter 520 and the DC / DC converter 510.

  Further, as a DC / DC converter having a magnetic storage function, for example, a DC / DC converter in which a step-up (step-down) rate is variable by charging two series capacitors alternately is disclosed (for example, a patent) Reference 1). This DC / DC converter charges the capacitors C1 and C2 individually from the DC power supply input unit by controlling on / off of the switches SW1 to SW4, and is connected between the input terminal and the switches SW1 to SW4. Magnetic energy is stored in the inductor L (inductor for varying the step-up / step-down ratio), and the capacitors C1 and C2 are charged by the current from the inductor L to obtain a boosted voltage at the output section.

  A DC / DC converter comprising a series capacitor and an electric switch connected in parallel thereto, and controlling a step-down voltage of one voltage level by an inrush current preventing inductor disposed between each capacitor and the electric switch. Is also disclosed (see, for example, Patent Document 2).

JP 2005-224060 A International Publication No. WO00 / 45185 Pamphlet

  However, in the conventional DC / DC converter 510, there is noise radiation from the switch elements S1 and S2. For example, the battery 600 is disposed in the rear of the vehicle, and the noise is generated by the DC / DC converter 510 in the front of the vehicle. In the case of being arranged, the length of the wiring 550 from the battery 600 is 2 m or more, which may affect the peripheral devices. For this reason, a noise filter 520 and a strict shielded cable are required (see FIGS. 16 and 17).

  The present invention has been devised in view of the above problems, has a magnetic storage function for making step-up (step-down) variable, reduces conduction noise from an input line during switching, and emits noise. It is an object of the present invention to provide a DC / DC converter that can suppress the influence on peripheral devices and prevent the influence on peripheral devices.

  In order to solve the above problems, a DC / DC converter according to claim 1 of the present invention includes an input unit having a positive electrode side terminal and a negative electrode side terminal, an output unit having a positive electrode side terminal and a negative electrode side terminal, A smoothing capacitor having one end connected to the positive terminal of the input unit and the other end connected to the negative terminal of the input unit, and a plurality of switch elements provided between the input unit and the output unit A DC / DC converter that performs power conversion by switching the plurality of switch elements, wherein the first inductor is connected to the smoothing capacitor with respect to the positive terminal of the input unit. In parallel connection, one end is connected to the positive terminal of the input unit, the other end is connected to the positive terminal of the energization control unit, and the second inductor is connected to the negative terminal of the input unit Against Serial have a relationship of the smoothing capacitor connected in parallel, and one end connected to the negative terminal of the input section, and the other end is connected to the negative terminal of the power supply controller.

  With such a configuration, one inductor having a magnetic storage function, which is one of the components of a conventional DC / DC converter, is replaced with two configurations of a first inductor and a second inductor. Thus, a DC / DC converter having a magnetic storage function and a noise filter function can be configured.

  The DC / DC converter according to claim 2 of the present invention is the DC / DC converter according to claim 1, wherein the energization control unit includes a first switch element and a second switch element. One end of the switch element is connected to the other end of the first inductor, the other end is connected to the positive terminal of the output unit, and the second switch element has one end other than the first inductor. An end is connected to one end of the first switch element, and the other end is connected to the other end of the second inductor and a negative terminal of the output unit.

  With such a configuration, a conventional DC / DC converter having an energization control unit composed of two switch elements can be provided with a magnetic storage function and a noise filter function.

  According to a third aspect of the present invention, in the DC / DC converter according to the first aspect, the DC / DC converter according to the first aspect is a magnetic cancellation type DC / DC converter, and the primary winding and the secondary winding are provided via a core. Are magnetically coupled to each other and connected to the reverse winding with a 1: 1 turns ratio, and the other end of the first inductor is connected to the common terminal of the primary winding and the secondary winding. The power supply controller further includes a cancellation type transformer, and the energization control unit includes a first switch element, a second switch element, a third switch element, and a fourth switch element, and the first switch element includes: One end is connected to a terminal opposite to the common terminal of the primary winding, and the other end is connected to the other end of the second pre-second inductor and the negative terminal of the output unit, and the second switch One end of the element is connected to the terminal opposite to the common terminal of the primary winding. The other end is connected to the positive terminal of the output unit, the third switch element has one end connected to the terminal opposite to the common terminal of the secondary winding, and the other end connected to the second terminal. The other end of the inductor and the negative terminal of the output unit are connected. The fourth switch element has one end connected to a terminal opposite to the common terminal of the secondary winding and the other end connected to the output. It is connected to the positive terminal of the part.

  With such a configuration, a conventional magnetic cancellation type buck-boost DC / DC converter having a magnetic cancellation type transformer and an energization control unit including four switch elements has a magnetic storage function and a noise filter function. Can be provided.

  According to a fourth aspect of the present invention, in the DC / DC converter according to the first aspect, the DC / DC converter according to the first aspect is a magnetic cancellation type DC / DC converter, and the primary winding and the secondary winding are provided via a core. Are magnetically coupled to each other and connected to the reverse winding with a 1: 1 turns ratio, and the other end of the first inductor is connected to the common terminal of the primary winding and the secondary winding. The power supply controller further includes a cancellation type transformer, and the energization control unit includes a first switch element, a first diode, a second switch element, and a second diode, and the first switch element has one end. The primary winding is connected to a terminal opposite to the common terminal, the other end is connected to the other end of the second inductor and a negative terminal of the output unit, and the first diode has one end Is connected to the terminal opposite to the common terminal of the primary winding, Is connected to the positive terminal of the output section, and the second switch element has one end connected to a terminal opposite to the common terminal of the secondary winding and the other end connected to the second inductor. One end of the second diode is connected to a terminal opposite to the common terminal of the secondary winding, and the other end is connected to the positive terminal of the output unit. It is connected to the side terminal.

  With such a configuration, a conventional magnetic cancellation type unidirectional step-up DC / DC converter having a magnetic cancellation type transformer and an energization control unit including two switch elements and two diodes, A magnetic storage function and a noise filter function can be provided.

  In the DC / DC converter according to claim 5 of the present invention, the DC / DC converter according to claim 1 is a magnetic canceling type DC / DC converter, and the primary winding and the secondary winding are provided via the core. Are magnetically coupled to each other and connected to the reverse winding with a 1: 1 turns ratio, and the other end of the first inductor is connected to the common terminal of the primary winding and the secondary winding. The power supply controller further includes a cancellation type transformer, and the energization control unit includes a first diode, a first switch element, a second diode, and a second switch element, and the first diode has one end. Is connected to the terminal on the opposite side of the common terminal of the primary winding, the other end is connected to the other end of the second inductor and the negative terminal of the output unit, the first switch element is One end is connected to the terminal opposite to the common terminal of the primary winding. The other end is connected to the positive terminal of the output unit, the second diode has one end connected to a terminal opposite to the common terminal of the secondary winding, and the other end connected to the second inductor. And the other end of the second switch element is connected to a terminal opposite to the common terminal of the secondary winding, and the other end is connected to the output section. It is characterized by being connected to the positive electrode side terminal.

  With such a configuration, a conventional magnetic cancellation type unidirectional step-down DC / DC converter having a magnetic cancellation type transformer and an energization control unit including two diodes and two switch element diodes is provided. A magnetic storage function and a noise filter function can be provided.

  According to a sixth aspect of the present invention, there is provided a DC / DC converter according to the first aspect, wherein the DC / DC converter of the first aspect is a switched capacitance type DC / DC converter, wherein the first capacitor and the second capacitor connected in series A capacitor is further provided between the energization control unit and the output unit, and the energization control unit includes a first switch element, a second switch element, a third switch element, and a fourth switch element, The first switch element has one end connected to the other end of the first inductor, the other end connected to the positive electrode side of the first capacitor and the positive electrode side terminal of the output unit, and the second switch The other end of the element is connected to the other end of the first inductor, one end is connected to the negative side of the first capacitor and the positive side of the second capacitor, and the third switch element is Is connected to the other end of the second inductor, the other end is connected to the negative side of the first capacitor and the positive side of the second capacitor, and the other end of the fourth switch element is the first side. 2 is connected to the other end of the inductor, and one end is connected to the negative side of the second capacitor and the negative side terminal of the output unit.

  With such a configuration, a conventional switched capacitance step-up / step-down DC / DC converter having two series capacitors and an energization control unit including four switch elements has a magnetic storage function and a noise filter function. Can be provided.

  According to a seventh aspect of the present invention, in the DC / DC converter according to the first aspect, the DC / DC converter according to the first aspect is a switched capacitance type DC / DC converter, wherein the first capacitor and the second capacitor connected in series are provided. A capacitor is further provided between the energization control unit and the output unit, and the energization control unit includes a first diode, a first switch element, a second switch element, and a second diode, One diode has one end connected to the other end of the first inductor, the other end connected to a positive electrode side of the first capacitor and a positive electrode side terminal of the output unit, and the first switch element is The other end is connected to the other end of the first inductor, one end is connected to the negative side of the first capacitor and the positive side of the second capacitor, and the second switch element has one end The other end of the second inductor is connected, the other end is connected to the negative side of the first capacitor and the positive side of the second capacitor, and the other end of the second diode is the second side. It is connected to the other end of the inductor, and one end is connected to the negative electrode side of the second capacitor and the negative electrode side terminal of the output unit.

  With such a configuration, the conventional switched capacitance type unidirectional step-up DC / DC converter having two series capacitors, two diodes, and two switch elements and having a current storage control unit has a magnetic storage. A function and a noise filter function can be provided.

  In the DC / DC converter according to claim 8 of the present invention, the DC / DC converter according to claim 1 is a switched capacitance type DC / DC converter, wherein the first capacitor and the second capacitor connected in series are provided. A capacitor is further provided between the energization control unit and the output unit, and the energization control unit includes a first switch element, a first diode, a second diode, and a second switch element, One switch element has one end connected to the other end of the first inductor, the other end connected to a positive side of the first capacitor and a positive side terminal of the output unit, and the first diode is The other end is connected to the other end of the first inductor, one end is connected to the negative side of the first capacitor and the positive side of the second capacitor, and the second diode has one end connected to the front. The other end of the second inductor is connected, the other end is connected to the negative electrode side of the first capacitor and the positive electrode side of the second capacitor, and the other end of the second switch element is the second capacitor. It is connected to the other end of the inductor, and one end is connected to the negative electrode side of the second capacitor and the negative electrode side terminal of the output unit.

  With such a configuration, magnetic storage is performed in a conventional switched capacitance type unidirectional step-down DC / DC converter having two series capacitors, an energization control unit including two switch elements and two diodes. A function and a noise filter function can be provided.

  The DC / DC converter according to a ninth aspect of the present invention is the DC / DC converter according to the first aspect, wherein the first inductor has a first winding that generates a magnetic flux when energized wound around the first core. The second inductor is configured such that a second winding that generates a magnetic flux when energized is wound around a second core, and the first core and the second core are configured independently. It is characterized by being.

  With such a configuration, it is possible to realize a DC / DC converter having a high noise radiation reduction effect that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  The DC / DC converter according to claim 10 of the present invention is the DC / DC converter according to claim 9, wherein each of the first core and the second core has a gap. Features.

  With such a configuration, magnetic saturation can be prevented. In addition, it is possible to implement a DC / DC converter having a high noise radiation reduction effect that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  The DC / DC converter according to an eleventh aspect of the present invention is the DC / DC converter according to the first aspect, wherein the first inductor includes a first winding that generates a magnetic flux when energized, and the second inductor. The inductor has a second winding that generates a magnetic flux when energized, and the first winding and the second winding have a single closed magnetic circuit so that the magnetic fluxes generated when energized mutually strengthen each other. One formed core is shared and wound around different opposing portions of the core.

  With such a configuration, it is possible to implement a DC / DC converter having a small-sized inductor core that suppresses noise generated during switching of the switching element together with the magnetic storage function from being radiated from the input line.

  A DC / DC converter according to a twelfth aspect of the present invention is characterized in that, in the DC / DC converter according to the eleventh aspect, a gap (gap) is formed in an opposing portion of the core.

  With such a configuration, magnetic saturation can be prevented. In addition, it is possible to implement a DC / DC converter having a small-sized inductor core that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  The DC / DC converter according to a thirteenth aspect of the present invention is the DC / DC converter according to the first aspect, wherein the first inductor has a first winding that generates a magnetic flux when energized, and the second The inductor has a second winding that generates a magnetic flux when energized, and the first winding and the second winding have two closed magnetic paths so that the magnetic fluxes generated by each other can be strengthened. Each of the cores is wound around one core, and the core has a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg, and the first winding is The second winding is wound around the other side magnetic leg, and the second winding is wound around the other side magnetic leg.

  With such a configuration, it is possible to implement a DC / DC converter having a small-sized inductor core that suppresses noise generated during switching of the switching element together with the magnetic storage function from being radiated from the input line.

  The DC / DC converter according to a fourteenth aspect of the present invention is the DC / DC converter according to the first aspect, wherein the first inductor has a first winding that generates a magnetic flux when energized, and the second The inductor has a second winding that generates a magnetic flux when energized, and the first winding and the second winding have two closed magnetic paths so that the magnetic fluxes generated by each other can be strengthened. Each of the cores is wound around each of the formed cores, and the core includes a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg, and the first winding and The second winding is wound so as to be stacked on the central magnetic leg, and a gap (gap) is formed between the central magnetic leg and the side magnetic leg.

  With such a configuration, magnetic saturation can be prevented. In addition, it is possible to implement a DC / DC converter having a small-sized inductor core that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  A DC / DC converter according to a fifteenth aspect of the present invention is the DC / DC converter according to the first aspect, wherein the first inductor has a first winding that generates a magnetic flux when energized, and the second The inductor has a second winding that generates a magnetic flux when energized, and the first winding and the second winding have two closed magnetic paths so that the magnetic fluxes generated by each other can be strengthened. Each of the cores is wound around one core to be formed, and the core includes a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg. A connecting portion connecting the two side magnetic legs, wherein the first winding and the second winding are wound so as to be stacked on the central magnetic leg across the connecting portion; Features.

  With such a configuration, it is possible to implement a DC / DC converter having a small-sized inductor core that suppresses noise generated during switching of the switching element together with the magnetic storage function from being radiated from the input line.

The DC / DC converter according to the present invention has a magnetic storage function for making the step-up (step-down) variable, and suppresses noise emission from the input line at the time of switching, thereby preventing influence on peripheral devices. And the conventional noise filter can be eliminated.
Therefore, it is possible to reduce the number of components of the power converter in the electric and electric assist system of the automobile and to reduce the manufacturing cost.

1 is a circuit diagram for explaining a core-separated DC / DC converter according to a first embodiment of the present invention. It is a circuit diagram for demonstrating the core separation type DC / DC converter of the 2nd Embodiment of this invention. (A) is a magnetic cancellation type buck-boost type DC / DC converter, and (b) is a switched capacitance type buck-boost type DC / DC converter. It is a circuit diagram for demonstrating the core separation type | mold magnetic cancellation type DC / DC converter of the 3rd Embodiment of this invention. (A) is a magnetic cancellation type unidirectional step-up DC / DC converter, and (b) is a magnetic cancellation type unidirectional step-down DC / DC converter. It is a circuit diagram for demonstrating the core separation type switched capacitance type DC / DC converter of the 4th Embodiment of this invention. (A) is a switched capacitance type unidirectional step-up DC / DC converter, and (b) is a switched capacitance type unidirectional step-down DC / DC converter. It is a figure for demonstrating the case where two inductors in the DC / DC converter of embodiment of this invention are made into a core shared type inductor core, (a) is a current direction to a core shared type DC / DC converter. It is the circuit diagram shown, (b) is explanatory drawing of the inductor core which showed the winding direction to a core, and a magnetic flux direction, (c) is the winding direction to a core, a magnetic flux direction, and a leakage magnetic flux direction It is explanatory drawing of the inductor core which has the center magnetic leg and side magnetic leg which showed. It is a figure for demonstrating the inductor core of the general noise filter as a comparative example, (a) is a circuit diagram for demonstrating the structure which showed the electric current direction to the general noise filter, (b ) And (c) are explanatory diagrams of the inductor core showing the winding direction to the core and the magnetic flux direction. It is a circuit diagram for demonstrating the DC / DC converter of a core shared type of the 5th Embodiment of this invention. (A) is a DC / DC converter, (b) is a magnetic cancellation type buck-boost type DC / DC converter, and (c) is a switched capacitance type buck-boost type DC / DC converter. It is a figure for demonstrating embodiment of the inductor core in the core isolation | separation type | mold of the 6th Embodiment of this invention, and a core shared type DC / DC converter. The figure also shows a comparison of the magnitudes of noise emission reduction effects and physiques of the embodiments of each inductor core. It is a figure which shows the outline | summary of the measuring system and measuring apparatus for measuring the noise radiation reduction effect of a DC / DC converter. It is a figure for demonstrating the measurement result about the noise radiation reduction effect of the DC / DC converter of a core separation type switched capacitance type buck-boost type of this invention, (a) is a circuit diagram, (b) is obtained. Is a measured waveform. It is a figure for demonstrating the noise current value obtained by the measurement of FIG. 10, (a) is a circuit diagram, (b) is a waveform of a noise current value (comparison value). It is a figure for demonstrating the measurement result about the noise radiation of the conventional switched capacitance type buck-boost type DC / DC converter (comparative example 1), (a) is a circuit diagram, (b) was obtained. It is a measurement waveform. It is a figure for demonstrating the measurement result about the noise radiation of the conventional switched capacitance type buck-boost type DC / DC converter (comparative example 2), (a) is a circuit diagram, (b) was obtained. It is a measurement waveform. It is a figure for demonstrating the noise current value obtained by the measurement of FIG. 12, (a) is a circuit diagram, (b) is a waveform of a noise current value (comparison value). It is a figure for demonstrating the noise current value obtained by the measurement of FIG. 13, (a) is a circuit diagram, (b) is a waveform of a noise current value (comparison value). It is a figure for demonstrating the structure of the electric power converter of the electric drive of the conventional motor vehicle, and an electrically-assisted system. It is a figure for demonstrating the structure of the conventional noise filter and DC / DC converter.

  An embodiment of a DC / DC converter according to the present invention will be described with reference to FIGS. Furthermore, measurement results according to the embodiment will be described with reference to FIGS. 9 to 15.

(First embodiment)
A core-separated DC / DC converter 100 according to a first embodiment of the present invention will be described with reference to FIG.

  The core-separated type DC / DC converter 100 includes an input unit in which DC input is performed between a positive electrode terminal and a negative electrode terminal, and a smoothing capacitor C0 that reduces impedance due to the wiring length from the battery to the input unit and the internal resistance of the battery. Inductor L1 and inductor L2 that store magnetic energy and have a filter effect that suppresses noise from the switch elements constituting energization control unit 10, and energization control unit 10 that turns on / off switch element S1 and switch element S2 It consists of. Here, the switch element S1 and the switch element S2 use an IGBT having a transistor function capable of a large current and high withstand voltage operation and a diode function connected in parallel. The core-separated DC / DC converter 100 further includes a capacitor C1 that smoothes the output voltage of the energization control unit 10, and an output unit that outputs the output voltage between the positive terminal and the negative terminal. Composed. Although not shown, a control circuit unit for controlling the operation of the core-separated DC / DC converter 100 of this embodiment is separately provided.

  In the core-separated DC / DC converter 100 of the present embodiment, the input unit includes a positive terminal and a negative terminal where DC input is performed. The smoothing capacitor C0 is a capacitor that reduces the impedance of the resistance due to the wiring length from the battery to the input portion and the internal resistance of the battery, and also functions as a noise filter by forming an inductor and an LC circuit. Therefore, an electrolytic capacitor or a film capacitor having a low internal resistance is suitable. The inductor L1 and the inductor L2 are main components of the present invention, and are inductors that have a filter effect that accumulates magnetic energy and suppresses noise from the switch elements that constitute the energization control unit 10. As the core constituting the inductor, it is preferable to use a ferrite core, a dust core, or the like in consideration of miniaturization, weight reduction, high frequency compatibility, and common use. The energization control unit 10 includes a switch element S1 and a switch element S2, and controls on / off operations of these switch elements. The switch element S1 and the switch element S2 are IGBTs capable of operating with a large current and a high withstand voltage, and it is preferable to use a switch with a flywheel diode. Further, when high speed switching is required, a MOSFET or the like is preferable. The switch element S1 and the switch element S2 may be SiC transistors or GaN transistors having high withstand voltage / environment resistance characteristics. The capacitor C <b> 1 is a capacitor that smoothes the output from the energization control unit 10. The output unit outputs the output voltage from the capacitor C1 from the positive terminal and the negative terminal.

  Next, the operation of the core-separated DC / DC converter 100 will be described. In the DC / DC converter 100, a DC voltage is applied between the positive terminal and the negative terminal of the input unit. Then, the input voltage is smoothed by the smoothing capacitor C0. Next, when the switch element S2 is turned on, magnetic energy is accumulated in the inductor L1 and the inductor L2, and when the switch element S2 is turned off, the accumulated magnetic energy is magnetized with a predetermined duty via the diode function of the switch element S1. Energy is output to the output unit. Further, when the switch element S1 is turned on, magnetic energy is accumulated in the inductor L1 and the inductor L2, and when the switch element S1 is turned off, the accumulated magnetic energy is output to the input unit via the diode of the switch element S2. Thereby, direct current energy moves from the output unit to the input unit.

  With this configuration, in the core-separated DC / DC converter 100 of this embodiment, the inductor L1 and the inductor L2 function as a noise filter with the smoothing capacitor C0 as well as the magnetic storage function. And noise generated in switching of the switch element S2 can be reduced, and noise radiation from the input line can be suppressed. Furthermore, the noise filter 520 (see FIGS. 16 and 17), which is a component of the conventional power control unit (PCU) 500, can be deleted.

(Second Embodiment)
Next, as a second embodiment, referring to FIG. 2 (a) and FIG. 2 (b), a core-separated magnetic offset type buck-boost DC / DC to which the main matter of the present invention is applied is applied. An embodiment of a converter 200 and a core separated switched capacitance type buck-boost DC / DC converter 300 will be described.

  FIG. 2A shows a mode in the step-up operation of the magnetic cancellation type step-up / step-down DC / DC converter 200. In the case of the step-up DC / DC converter, as shown in FIG. 2A, the two terminals on the left side are input terminals on the low voltage side, and the two terminals on the right side are output terminals on the high voltage side. In the case of the step-down DC / DC converter, the right terminal on the high voltage side serves as an input terminal, and the left terminal on the low voltage side serves as an output terminal.

  Here, the configuration and operation of the boost type configuration shown in FIG. 2A will be described. First, as a configuration, a DC / DC converter 200 in a magnetic cancellation type step-up type includes an input unit in which DC input is performed between a positive electrode terminal and a negative electrode terminal, a resistance depending on a wiring length from the battery to the input unit, and a battery. A smoothing capacitor C0 for reducing the impedance of the internal resistance, inductors L1 and L2 each having one end connected in series to both ends of the smoothing capacitor C0, and magnetic cancellation having one end connected to the other end of the inductor L1. Type switch T125, and switch element S1, switch element S2, switch element S3, and switch element S4 connected to the other end of this magnetic cancellation type transformer T125 and the other end of inductor L2 are turned on / off. An energization control unit 20 that performs, a capacitor C1 that smoothes the output voltage of the energization control unit 20, and an output voltage that is a positive terminal Beauty is configured by an output unit to be outputted between the negative terminal. Although not shown, a control circuit unit for controlling the entire operation of the core-separated magnetic cancellation type buck-boost DC / DC converter 200 of this embodiment is separately provided.

  That is, in the DC / DC converter 200 of the magnetic cancellation type boost type according to the present embodiment, the input unit includes a positive terminal and a negative terminal where DC input is performed. The smoothing capacitor C0 is a capacitor that reduces the impedance of the resistance due to the wiring length from the battery to the input portion and the internal resistance of the battery, and also functions as a noise filter by forming an inductor and an LC circuit. The inductor L1 and the inductor L2 are main components of the present invention. One end of each of the inductor L1 and the inductor L2 is connected in series to both ends of the smoothing capacitor C0, accumulates magnetic energy, and noise from a switch element constituting the energization control unit 20 It is an inductor which has a filter effect which suppresses. In the magnetic cancellation type transformer T125, the primary winding (lower side) and the secondary winding (upper side) are magnetically coupled via the core, and are connected to the reverse winding with a 1: 1 turns ratio. Is a transformer. The energization control unit 20 includes switch elements S1 to S4, and controls on / off operations of these switch elements. The switch elements S1 to S4 are IGBTs having a transistor function capable of large current and high breakdown voltage operation and a diode function connected in parallel. The capacitor C <b> 1 is a capacitor that smoothes the output from the energization control unit 20. The output unit outputs the output voltage from the capacitor C1 from the positive terminal and the negative terminal.

  In the magnetic cancellation type transformer T125, the primary winding (lower side) and the secondary winding (upper side) are magnetically coupled via the core, and are connected to the reverse winding with a 1: 1 turns ratio. ing. The dot symbols attached to the illustrated primary and secondary windings indicate the high potential side when a voltage is induced. For example, by using a ferrite core as the core, it is possible to cope with a high frequency and to reduce the weight of the magnetic cancellation type transformer T125.

  In addition, the connection relationship between each switch element S1 to S4 of the energization control unit 20 and other parts will be described. One end of the switch element S1 is connected to a terminal opposite to the common terminal of the primary winding of the magnetic canceling transformer T125, and the other end is connected to the other end of the inductor L2 and the negative terminal on the output side. It is connected to the. The switch element S2 has one end connected to a terminal opposite to the common terminal of the primary winding of the magnetic canceling transformer T125, and the other end connected to the positive terminal of the output unit. One end of the switch element S3 is connected to the terminal opposite to the common terminal of the secondary winding of the magnetic canceling transformer T125, and the other end is connected to the other end of the inductor L2 and the negative terminal of the output unit. Has been. The switch element S4 has one end connected to a terminal opposite to the common terminal of the secondary winding of the magnetic cancellation type transformer T125, and the other end connected to the positive terminal of the output unit.

  Next, the operation of the step-up type shown in FIG. 2A will be described. First, a signal is given from the separately provided control circuit unit to the gates of the switch element S1 and the switch element S3 of the energization control unit 20, and the switch element S1 and the switch element S3 are alternately turned on and off. The duty of the ON operation time of the switch element S1 and the switch element S3 is changed by shifting the phase according to a desired step-up (step-down) rate. At this time, only the off signal is given to the gates of the switch element S2 and the switch element S4, and the switch element S2 and the switch element S4 are always held in the off state. In the case of the boosting operation, the DC voltage DC + that is the input voltage input to the input unit becomes the input voltage, the DC voltage DC + is converted, and the output unit has a voltage value approximately twice the input voltage. A certain DC voltage obtained by adding the input voltage DC +, the induced voltage of the inductors L1 and L2, and the induced voltage of the secondary winding of the magnetic cancellation type transformer T125 is output to the output unit as an output voltage. Therefore, the boosting operation is performed in the forward direction from the low voltage input unit side toward the high voltage side of the output unit.

Further, a case where the switch element S1 and the switch element S3 are alternately turned on / off will be described.
When only the switch element S1 is turned on, an exciting current flows through the primary winding (lower side) of the magnetic cancellation type transformer T125. This exciting current flows through the route of the DC + terminal of the input unit, the inductor L1, the switch element S1, and the inductor L2. While the switch element S1 is in the on state, the exciting current gradually increases, and when the switch element S1 is turned off, the exciting current gradually decreases and becomes zero. During this time, magnetic energy is accumulated in the inductor L1 and the inductor L2. When the switch element S1 is turned off, the stored magnetic energy is released from the inductor L1 and the inductor L2. The exciting currents emitted from the inductors L1 and L2 flow through the primary winding of the magnetic cancellation type transformer T125 and the diode portion of the switch element S2 to the + terminal of the output unit.

  Further, when an exciting current flows in the primary winding (lower side) of the magnetic cancellation type transformer T125, the exciting current flows in the secondary winding (upper side) of the magnetic cancellation type transformer T125 due to mutual induction. appear. This exciting current flows to the + terminal of the output section through the diode portion of the switch element S4. The excitation current of the secondary winding is generated with a variation characteristic substantially the same as that of the primary winding, and is generated with substantially the same value from the winding ratio. The smoothing capacitor C1 is charged by the excitation current of the secondary winding of the magnetic cancellation type transformer T125, and as a result, the output voltage of the output unit is output.

  On the other hand, when only the switching element S3 is turned on, an exciting current flows in the secondary winding (upper side) of the magnetic cancellation type transformer T125. This exciting current is the DC + terminal of the input section, the inductor L1, the switching element S3, and And flows to the inductor L2. While the switch element S3 is in the on state, the exciting current gradually increases, and when the switch element S3 is turned off, the exciting current gradually decreases and becomes zero. During this time, magnetic energy is accumulated in the inductor L1 and the inductor L2. When the switch element S3 is turned off, the stored magnetic energy is released from the inductor L1 and the inductor L2. The exciting currents emitted from the inductors L1 and L2 flow through the secondary winding of the magnetic cancellation type transformer T125 and the diode portion of the switch element S4 to the + terminal of the output unit.

  When an excitation current flows through the secondary winding (upper side) of the magnetic cancellation type transformer T125, the excitation current flows through the primary winding (lower side) of the magnetic cancellation type transformer T125 due to mutual induction. appear. This exciting current flows to the + terminal of the output section through the diode portion of the switch element S2. The exciting current of the primary winding is generated with substantially the same change characteristics as the exciting current of the secondary winding, and is generated with substantially the same value from the winding ratio. The smoothing capacitor C1 is charged by the exciting current of the primary winding of the magnetic cancellation type transformer T125, and as a result, the output voltage of the output unit is output.

  Therefore, in the step-up operation of the magnetic cancellation type buck-boost type DC / DC converter 200, since the magnetic cancellation type transformer T125 is included, when the switch element S1 is turned on and the switch element S3 is turned off, the magnetic cancellation type transformer An exciting current flows in the primary winding (lower side) of T125, and at the same time, an exciting current also flows in the secondary winding (upper side) of the magnetic cancellation type transformer T125 in a direction to cancel the magnetization of the transformer T125. Magnetic energy is supplied to the positive terminal of the output section through the secondary winding (upper side). When the switch element S3 is turned on and the switch element S1 is turned off, an exciting current flows through the secondary winding (upper side) of the magnetic cancellation type transformer T125, and at the same time, the primary winding of the magnetic cancellation type transformer T125. An exciting current also flows in the line (lower side) in a direction that cancels the magnetization of the transformer T125, and magnetic energy is supplied to the + terminal of the output unit through the primary winding (lower side). As a result, the directions of the excitation currents of the primary winding (lower side) and the secondary winding (upper side) of the magnetic cancellation type transformer T125 are reversed, and the DC magnetization of the magnetic cancellation type transformer T125 is changed. This cancels out the magnetic saturation. Therefore, even a small core can handle a larger amount of power.

  Further, the DC voltage output from the output unit is provided with the inductor L1 and the inductor L2, so that the boost function of the output voltage with respect to the input voltage can be induced electromotive force based on the inductor L1 and the inductor L2, and the magnetic cancellation type. This is realized as the sum of the induced electromotive force of the primary winding (lower side) and the secondary winding (upper side) of the transformer T125. As a result, by changing the duty of the ON operation time of the switch elements S1 and S3 to 50% or less, the input voltage can be boosted to a desired value in a range of 1 to 2 times, and the duty is 50 It is possible to boost the voltage by a desired value more than twice by providing a lap period with a variable value of at least%.

  Furthermore, in the core-separated magnetic cancellation type buck-boost type DC / DC converter 200 of this embodiment, the inductor L1 and the inductor L2 are configured to generate noise in the smoothing capacitor C0 together with the magnetic storage function. Since it functions as a filter, it is possible to reduce noise generated in switching of the switch element S1 and the switch element S3, and to suppress noise emission from the input line. Furthermore, the noise filter 520 (see FIGS. 16 and 17), which is a component of the conventional power control unit (PCU) 500, can be deleted.

  Next, the configuration and the operation of the step-up operation of the core-separated switched capacitance type step-up / step-down DC / DC converter 300 will be described with reference to FIG.

  First, the configuration of the DC / DC converter 300 in the form of a core-separated switched-capacitance step-up type includes an input section in which DC input is performed between a positive terminal and a negative terminal, and a wiring length from the battery to the input section. The smoothing capacitor C0 for smoothing the DC input noise, the inductor L1 and the inductor L2 having one end connected in series to both ends of the smoothing capacitor C0, and the inductor L1 An energization control unit 30 including a switch element S1 and a switch element S2 connected in parallel to the other end, a switch element S3 and a switch element S4 connected in parallel to the other end of the inductor L2, and a switch element S1; In addition to the capacitor C1 connected to the other end of the switch element S2, the switch element S3 and the switch element S4 And connected capacitor C2 and series capacitor 35 connected in series, is configured to include an output section for the two ends of the series capacitor 35 and the positive and negative terminals on. Although not shown, a separate control circuit unit is provided for controlling the overall operation of the DC / DC converter 300 of the core-type switched capacitance boost type.

  Here, as in the first embodiment, the switch elements S1 to S4 use IGBTs having a transistor function capable of large current and high breakdown voltage operation and a diode function connected in parallel.

  The operation of the DC / DC converter 300 of this core separated switched capacitance type step-up type will be described. First, signals are given to the gates of the switch element S2 and the switch element S3 of the energization control unit 30 from a separately provided control circuit unit, and the switch element S2 and the switch element S3 are alternately turned on and off. The duty of the ON operation time of the switch element S2 and the switch element S3 is changed by shifting the phase by 50% or less so as not to be in the ON state at the same time. At this time, only the off signal is given to the gates of the switch element S1 and the switch element S4, and the switch element S1 and the switch element S4 are always held in the off state. In this way, the input voltage of the input unit is boosted from 1 to 2 times and output from the output unit. Further, if the duty ratio is 50% or more, the magnetic energy is accumulated in L1 and L2 during the time when S2 and S3 are simultaneously turned on, and it is possible to boost more than twice by using the accumulated energy. It is.

  Then, the capacitor C1 and the capacitor C2 are charged alternately, and at the same time, the magnetic energy is accumulated in the inductor L1 and the inductor L2 to boost the voltage.

  First, an operation when the capacitor C2 is charged in the boosting operation will be described. The gate voltage of the switch element S2 is applied and the switch element S2 is turned on. At this time, the other switch element S1, switch element S3, and switch element S4 are in the OFF state. A charging current flows through the route of the DC + terminal of the input unit, the inductor L1, the switch element S2, the capacitor C2, the diode part of the switch element S4, the inductor L2, and the DC− terminal of the input unit. At this time, the capacitor C2 is charged and magnetic energy is stored in the inductor L1 and the inductor L2.

  Subsequently, the switch S2 is turned off. At this time, the other switches S1, S3, and S4 are in an off state. Then, the magnetic energy stored in the inductor L1 and the inductor L2 is released, and the charging current becomes the inductor L1, the diode part of the switch element S1, the capacitor C1, the capacitor C2, the diode part of the switch element S4, the inductor L2, and It flows in the route of the DC-terminal of the input unit.

  On the other hand, the operation when the capacitor C1 is charged will be described. The gate voltage of the switch element S3 is applied and the switch element S3 is turned on. At this time, the other switch element S1, switch element S2, and switch element S4 are in the OFF state. A charging current flows through the DC + terminal of the input unit, the inductor L1, the diode portion of the switch element S1, the capacitor C1, the switch element S3, the inductor L2, and the DC-terminal of the input unit. At this time, the capacitor C1 is charged and magnetic energy is stored in the inductor L1 and the inductor L2.

  Subsequently, the switch S3 is turned off. At this time, the other switches S1, S2, and S4 are in an off state. Then, the magnetic energy stored in the inductor L1 and the inductor L2 is released, and the charging current becomes the inductor L1, the diode part of the switch element S1, the capacitor C1, the capacitor C2, the diode part of the switch element S4, the inductor L2, and It flows in the route of the DC-terminal of the input unit.

  In this way, a charging current is alternately passed from the input section to the capacitors C1 and C2 connected in series, and magnetic energy is accumulated in the inductor L1 and the inductor L2 by this charging current, and the inductor L1 and the inductor L2 The boosting operation is performed by charging the capacitor C1 and the capacitor C2 with the charging current generated by the release of the magnetic energy.

  Further, in the core separated switched capacitance type step-up / step-down DC / DC converter 300 of this embodiment, the inductor L1 and the inductor L2 are coupled with the magnetic storage function and the smoothing capacitor C0. Since it functions as a filter, it is possible to reduce noise generated in switching of the switch element S2 and the switch element S3 and to suppress noise emission from the input line. Furthermore, the noise filter 520 (see FIGS. 16 and 17), which is a component of the conventional power control unit (PCU) 500, can be deleted.

(Third embodiment)
Next, as a third embodiment, referring to FIG. 3 (a) and FIG. 3 (b), a core-separated magnetic canceling type unidirectional step-up DC to which the main matter of the present invention described above is applied. An embodiment of a DC / DC converter 211 and a magnetic cancellation type unidirectional step-down DC / DC converter 212 will be described.

  The two core-separated DC / DC converters of the present embodiment are composed of the basic configuration of the magnetic cancellation type buck-boost DC / DC converter 200 described with reference to FIG. 2A in the second embodiment. By replacing a predetermined switch element of the communication control unit 20 with a diode, a unidirectional step-up type and a unidirectional step-down type DC / DC converter with limited functions are obtained, and other main configurations And the function is the same as that of the magnetic cancellation type buck-boost type DC / DC converter 200 of the second embodiment. Here, only different points will be described.

  Specifically, in the magnetic cancellation type unidirectional step-up DC / DC converter 211 shown in FIG. 3A, the configuration of the energization control unit 21 is changed to a switch element S1, a switch element S2, a diode D1, and a diode D2. Thus, the function is limited to the step-up type described in the second embodiment. Therefore, when the switch element S1 and the switch element S3 described in the operation of the second embodiment have a function of performing the switch operation by the IGBT, and the switch element S2 and the switch element S4 are always used in the off state, That is, an operation corresponding to using only the diode characteristics of the switch element S2 and the switch element S4 is performed.

  Therefore, the relationship between the switch element and the diode of each energization control unit is the same as that of the switch element of the second embodiment, and the switch element and the diode of this embodiment are equivalent to the switch element S1. The diode D1 corresponds to the switch element S2, the switch element S2 corresponds to the switch element S3, and the diode D2 corresponds to the switch element S4. In the magnetic cancellation type unidirectional step-up DC / DC converter 211 configured as described above, the number of switches is reduced by replacing the switch elements with diodes.

  On the other hand, in the magnetic cancellation type unidirectional step-down DC / DC converter 212 of FIG. 3B, the configuration of the energization control unit 22 is a diode D1, a switch element S1, a diode D2, and a switch element S2. Thus, the function is limited to the step-down type described in the second embodiment. Therefore, when the switch element S2 and the switch element S4 described in the operation of the second embodiment have a function of performing the switch operation by the IGBT, and the switch element S1 and the switch element S3 are always used in the off state, That is, an operation corresponding to using only the diode characteristics of the switch element S1 and the switch element S3 is performed.

  Therefore, the relationship between the switch element and the diode of each energization control unit is the same as that of the switch element of the second embodiment, the diode D1 of the switch element and the diode of this embodiment corresponds to the switch element S1. The switch element S1 corresponds to the switch element S2, the diode D2 corresponds to the switch element S3, and the switch element S2 corresponds to the switch element S4. In the magnetic cancellation type unidirectional step-down DCDC converter 212 configured as described above, the number of switches is reduced by replacing the switch elements with diodes.

  With this configuration, in the core-separated magnetic cancellation type unidirectional step-up DC / DC converter 211 and magnetic cancellation type unidirectional step-down DC / DC converter 212 of this embodiment, the magnetic storage function At the same time, noise generated in switching of the switch element can be reduced, and noise emission from the input line can be suppressed. By replacing the switch element with a diode, it is possible to realize a DC / DC converter limited to the functions of the magnetic cancellation type unidirectional step-up type and unidirectional step-down type with a reduced number of switches.

(Fourth embodiment)
Next, as a fourth embodiment, referring to FIG. 4A and FIG. 4B, a core-separated switched capacitance type unidirectional step-up type DC to which the main matter of the present invention is applied is described. An embodiment of a DC / DC converter 311 and a switched capacitance type unidirectional step-down DC / DC converter 312 will be described.

  The two core-separated DC / DC converters of this embodiment are composed of the basic configuration of the switched capacitance type step-up / step-down DC / DC converter 300 described with reference to FIG. 2B in the second embodiment. By replacing the predetermined switch element of the communication control unit 30 with a diode, a switched capacitance type DC / DC converter having a unidirectional step-up type and a unidirectional step-down type function is obtained. The function is the same as that of the switched capacitance type buck-boost type DC / DC converter 300 of the second embodiment. Here, only different points will be described.

  Specifically, in the switched capacitance type unidirectional step-up DC / DC converter 311 of FIG. 4A, the configuration of the energization control unit 31 includes a diode D1, a switch element S2, a switch element S3, and a diode D2. Thus, the function is limited to the step-up type described in the second embodiment. Therefore, when the switch element S2 and the switch element S3 described in the operation of the second embodiment have a function of performing the switch operation by the IGBT, and the switch element S1 and the switch element S4 are always used in the off state, That is, an operation corresponding to using only the diode characteristics of the switch element S1 and the switch element S4 is performed.

  Therefore, the relationship between the switch element and the diode of each energization control unit is the same as that of the switch element of the second embodiment, the diode D1 of the switch element and the diode of this embodiment corresponds to the switch element S1. The switch element S2 corresponds to the switch element S2, the switch element S3 corresponds to the switch element S3, and the diode D2 corresponds to the switch element S4. In the switched capacitance type unidirectional step-up DC / DC converter 311 configured as described above, the number of switches is reduced by replacing the switch elements with diodes.

  On the other hand, in the switched capacitance type unidirectional step-down DC / DC converter 312 of FIG. 4B, the configuration of the energization control unit 32 is a switching element S1, a diode D1, a diode D2, and a switching element S2. Thus, the function is limited to the step-down type described in the second embodiment. Therefore, when the switch element S1 and the switch element S4 described in the operation of the second embodiment have a function of performing the switch operation by the IGBT, and the switch element S2 and the switch element S3 are always used in the off state, That is, an operation corresponding to using only the diode characteristics of the switch element S2 and the switch element S3 is performed.

  Therefore, the relationship between the switch element and the diode of each energization control unit is the same as that of the switch element of the second embodiment, and the switch element and the diode of this embodiment are equivalent to the switch element S1. The diode D1 corresponds to the switch element S2, the switch element S3 corresponds to the switch element S3, and the switch element 2 corresponds to the switch element S4. In the switched capacitance type unidirectional step-down DC / DC converter 312 configured as described above, the number of switches is reduced by replacing the switch elements with diodes.

  With this configuration, the core separation type switched capacitance type unidirectional step-up DC / DC converter 312 and the switched capacitance type unidirectional step-down DC / DC converter 312 according to the present embodiment have a magnetic storage function. At the same time, noise generated in switching of the switch element can be reduced, and noise emission from the input line can be suppressed. Then, by replacing the switch element with a diode, a DC / DC converter limited to the switched capacitance type unidirectional step-up type and unidirectional step-down type functions with a reduced number of switches can be realized.

  Next, assuming a case where the cores of the inductor L1 and the inductor L2 in the DC / DC converter of the present invention are shared, the shared inductor core is compared with a conventional general noise filter 520, as shown in FIG. A description will be given with reference to FIG.

  FIG. 5A shows a DC / DC converter 110 in which, for example, a core-sharing type inductor core is applied to the DC / DC converter 100 described in the first embodiment of the present invention. FIG. 5A is a circuit diagram showing the direction of the applied current and the direction of the induced magnetic field generated. The inductor L1 has a first winding that generates a magnetic flux when energized, and the inductor L2 has a second winding that generates a magnetic flux when energized. These first and second windings Is required to have a mutual inductance M so that magnetic fluxes generated by each other can be strengthened when energized.

  FIG. 5B is a diagram showing the winding direction of the inductor L2 and the direction of the generated magnetic flux with the inductor L1 in the present embodiment. Each winding is wound by sharing one core in which a closed magnetic path is formed so that the magnetic fluxes generated by each other are strengthened when energized.

  FIG. 5C shows the winding direction of the inductor L1 and the inductor L2 in this embodiment on one core having a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg. It is the figure which showed the magnetic flux direction to generate | occur | produce. Inductors L1 and L2 are wound around one and the other side magnetic legs, respectively.

  Therefore, in this embodiment, it has the same inductance value as when two coils are wound in series. It has a magnetic storage function and has an inductance necessary for boosting.

  FIG. 6A is a circuit diagram showing a current direction in a conventional general noise filter 520. The noise filter 520 is arranged so that magnetic fluxes generated upon energization cancel each other, that is, the mutual inductance M becomes 1. Then, an inductance is generated so as to strengthen the common mode noise and the noise is reduced. However, as shown in FIG. 6B and FIG. . Therefore, the noise filter 520 does not have a magnetic storage function.

(Fifth embodiment)
As a fifth embodiment, referring to FIG. 7A to FIG. 7C, the inductor L1 and the inductor L2, which are main items of the present invention, are configured to be a core shared type. Embodiments of a DC / DC converter 110, a magnetic cancellation type buck-boost DC / DC converter 210, and a switched capacitance type buck-boost DC / DC converter 310 will be described.

In the shared core type of this embodiment, the inductor L1 has a first winding that generates a magnetic flux when energized, and the inductor L2 has a second winding that generates a magnetic flux when energized. The first winding and the second winding are formed with a mutual inductance M so that the magnetic fluxes generated by each other when energized reinforce each other.

  Other configurations and functions include the DC / DC converter 100, the magnetic cancellation type buck-boost DC / DC converter 200, and the switched capacitance type buck-boost DC / DC described in the first and second embodiments. It is the same as each converter 300.

With this configuration, in the present embodiment of the core co-mold the DC / DC converter 110, a buck-type DC / DC converter 210 and switched capacitor chest type magnetic-field cancellation type buck-type DC / DC converter 310 The DC / DC converters of the first and second embodiments have an inductor core having a smaller physique than the configuration of the core-separated inductor L1 and inductor L2, and are generated in switching of the switch element together with the magnetic storage function DC / DC converter 110, magnetic cancellation type buck-boost type DC / DC converter 210, and switched capacitance type buck-boost type DC / DC converter 310 that can suppress noise emission and suppress noise emission from the input line. It has become.

(Sixth embodiment)
Next, based on the above considerations regarding the inductor core, a configuration example of the inductor core will be described with reference to FIGS. 8A and 8B as an embodiment of the DC / DC converter of the present invention.

  FIGS. 8A, 8A and 8A, 8B are diagrams for explaining an embodiment of an inductor core in the core-separated DC / DC converter 100 of the first embodiment. 8 (B) (c) to 8 (B) (g) are diagrams for describing an embodiment of an inductor core in the core shared DC / DC converter 110 of FIG. 5 (a).

  Furthermore, each embodiment in FIG. 8 is arranged with the horizontal axis representing the magnitude comparison of the noise radiation reduction effect and the physique of each inductor core embodiment. In FIG. 8, the noise radiation reducing effect is greater and the physique is larger as it is arranged on the left side of the drawing. On the other hand, the noise radiation reduction effect is smaller and the physique is smaller as it is arranged on the right side of the page.

  In FIG. 8A (a), the inductor L1 has a winding that generates a magnetic flux when energized, wound around the core 1, and an inductor L2 has a winding that generates a magnetic flux when energized, wound around the core 2. The core 2 is configured independently. With this configuration, the DC / DC converter has a high noise radiation reduction effect that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  FIG. 8A (b) shows a form in which the core 1 and the core 2 each have a gap (gap) in the form of the core shown in FIG. 8A (a). Thus, magnetic saturation can be prevented by adopting a configuration in which a gap is provided. In addition, the DC / DC converter has a high noise radiation reduction effect that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  In FIG. 8B (c), the inductor L1 has a first winding that generates a magnetic flux when energized, and the inductor L2 has a second winding that generates a magnetic flux when energized. The second winding is wound around different opposing portions of the core in common with one core in which one closed magnetic path is formed so that the magnetic fluxes generated by each other are strengthened when energized. With this configuration, the DC / DC converter has a small-sized inductor core that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  In FIG. 8B (d), the inductor L1 has a first winding that generates magnetic flux when energized, and the inductor L2 has a second winding that generates magnetic flux when energized. The second windings are wound around different opposing portions of the core in common with one core in which one closed magnetic circuit is formed so that the magnetic fluxes generated by each other when energized reinforce each other. A gap (gap) is formed in the facing portion of the core. With this configuration, magnetic saturation can be prevented. In addition, the DC / DC converter has a small-sized inductor core that suppresses noise generated during switching of the switching element together with the magnetic storage function from being radiated from the input line.

  In FIG. 8B (e), the inductor L1 has a first winding that generates a magnetic flux when energized, and the inductor L2 has a second winding that generates a magnetic flux when energized. The wire and the second winding are respectively wound around one core in which two closed magnetic paths are formed so that the magnetic fluxes generated by each other when energized are strengthened. The core has a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg, and the first winding is wound around one of the side magnetic legs. The winding is wound around the other side magnetic leg. Therefore, with this configuration, the DC / DC converter has a small-sized inductor that suppresses noise generated during switching of the switch element together with the magnetic storage function from being radiated from the input line.

  In FIG. 8B (f), the inductor L1 has a first winding that generates magnetic flux when energized, and the inductor L2 has a second winding that generates magnetic flux when energized. The winding and the second winding are respectively wound around one core in which two closed magnetic paths are formed so that magnetic fluxes generated by each other when energized are strengthened. The core has a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg, and the first winding and the second winding are stacked on the central magnetic leg. A gap (gap) is formed between the center magnetic leg and the side magnetic leg. With this configuration, magnetic saturation can be prevented. In addition, the DC / DC converter has a small-sized inductor core that suppresses noise generated during switching of the switching element together with the magnetic storage function from being radiated from the input line.

  In FIG. 8B (g), the inductor L1 has a first winding that generates a magnetic flux when energized, and the inductor L2 has a second winding that generates a magnetic flux when energized. The second windings are respectively wound around one core in which two closed magnetic paths are formed so that magnetic fluxes generated by each other are strengthened when energized. The core has a central magnetic leg and two side magnetic legs provided on both sides of the central magnetic leg, and has a connecting portion that connects the two side magnetic legs via the central magnetic leg. It is configured. Then, the first winding and the second winding are wound so as to be stacked on the central magnetic leg with the connecting portion interposed therebetween. With this configuration, the DC / DC converter has a small-sized inductor core that suppresses noise generated when switching the switching element together with the magnetic storage function from being radiated from the input line.

  As a result of comparing the size of the noise radiation reduction effect and the physique of the configuration of the inductor core of each of the embodiments in FIG. 8, the embodiment having a large noise radiation reduction effect is a core separation type configuration. Naturally, the size of the mold increases (FIGS. 8A, 8A, and 8B). On the other hand, although the embodiment with a small noise radiation reduction effect is a core shared type configuration, the physique is smaller in the core shared type (FIGS. 8B, 8C, and 8D). .

  Further, regarding the presence or absence of a gap, there is no clear difference in the effect of noise reduction, but there is a difference in that magnetic saturation can be prevented.

  Therefore, it seems that there is a trade-off between the noise radiation reduction effect and the size of the inductor core.

  Next, the results of confirming the effect of reducing the noise radiation from the input line in the DC / DC converter according to the embodiment of the present invention are compared with those of the conventional DC / DC converter, with reference to FIGS. I will explain.

First, the configuration and apparatus of a measurement system for a confirmation experiment will be described with reference to FIG. The measurement system for the confirmation experiment is a DC power supply device (manufactured by Takasago) 450 for applying a DC voltage to the input terminals DC + and DC− of the DC / DC converter, which is the sample 455 to be measured, RF current sensor probe (Schaffner CSP9160) 460, which is a current sensor for measuring noise, and an oscilloscope (Yokogawa DL7480) 470 for displaying the detected current waveform of the RF current sensor probe (Schaffner CSP9160) 460, measured A DC / DC converter as a sample and an output side terminal include an electronic load device (manufactured by Takasago) 480 via a capacitor _Cout . In this experiment, data of the oscilloscope 470 indicating the detected current waveform of the RF current sensor probe 460 that measures noise on the input line side of the DC / DC converter that is the sample 455 to be measured is used as the signal I _DC ( Common), the measurement sample 455 was measured for the following three types, and the measurement results were compared.

  10 and 11 show the noise on the input line side of the core-separated switched capacitance type step-up / step-down DC / DC converter 320 according to the second embodiment of the present invention as the sample 455 to be measured. The result measured using the sensor is shown.

  FIG. 10A is a circuit diagram of the core separation type switched capacitance type step-up / step-down DC / DC converter 320 used in this experiment. The inductance values of the inductor L1 and the inductor L2 are L / 2, respectively. The inductance value of the inductor L of the conventional DC / DC converter to be compared is set to ½.

FIG. 10B shows a result of measuring a noise waveform as a signal I _DC (Common) using a current sensor on the input line side. And it is the result of having measured Vce (SW2) and Vce (SW3) which are the switching voltage waveform of 2nd switch element S2 and 3rd switch element S3 as a reference.
It can be seen that the measurement signal I _DC (Common) on the input line side is hardly influenced when the second switch element S2 and the third switch element S3 are switched. That is, the noise radiation reduction effect from the input line was confirmed.

  On the other hand, FIGS. 12 to 15 show the results of measuring the noise on the input line side of the conventional switched capacitance type buck-boost DC / DC converters 400 and 410 as the measured sample 455 using a current sensor. (Comparative Example 1 and Comparative Example 2).

  FIG. 12A is a circuit diagram of a switched capacitance type step-up / step-down DC / DC converter 400 (Comparative Example 1), where the inductor L has an inductance value L and the smoothing capacitor C0 with respect to the positive terminal of the input unit. And one end is connected to the positive terminal of the input unit, and the other end is connected between the switch element S1 and the switch element S2.

FIG. 12B shows the result of measuring the noise waveform as a signal I _DC (Common) using a current sensor on the input line side. And it is the result of having measured Vce (SW2) and Vce (SW3) which are the switching voltage waveforms of switch element S2 and switch element S3 as a reference.
It was confirmed that the measurement signal I _DC (Common) on the input line side changed when the switching element S3 was switched. That is, it was confirmed that it was affected by noise from the input line.

  FIG. 13A is a circuit diagram of a switched capacitance type step-up / step-down DC / DC converter 410 (Comparative Example 2). The inductor L has an inductance value L and is smooth with respect to the negative terminal of the input unit. The capacitor C0 is connected in parallel, and one end is connected to the negative terminal of the input unit, and the other end is connected between the switch element S3 and the switch element S4.

FIG. 13B shows a result of measuring a noise waveform as a signal I _DC (Common) using a current sensor on the input line side. And it is the result of having measured Vce (SW2) and Vce (SW3) which are the switching voltage waveforms of switch element S2 and switch element S3 as a reference.
It was confirmed that the measurement signal I _DC (Common) on the input line side changed when the switching element S2 was switched. That is, as in Comparative Example 1, it was confirmed that the circuit was affected by noise from the input line.

The measurement results of this confirmation experiment will be described with reference to FIGS. 11, 14, and 15.
FIGS. 11 (a), 14 (a), and 15 (a) show circuit diagrams of DC / DC converters of the present embodiment, Comparative Example 1 and Comparative Example 2, respectively. Specifically, this is the same as FIG. 10 (a), FIG. 12 (a), and FIG. 13 (a).
11 (b), 14 (b), and 15 (b) are representative noises obtained by measuring the measurement signal I _DC (Common) on the input line side of each DC / DC converter. The measurement waveform of the change part of an electric current value is shown. When the noise current values of the changed portions of the respective measurement waveforms are compared, in this embodiment, the comparison value is 9, and the comparison values in Comparative Example 1 and Comparative Example 2 are 18 and 20, respectively. Considering that the large fluctuation of the measured waveform is the influence of the power source, it has been experimentally confirmed that the DC / DC converter according to the present embodiment can obtain a reduction effect of 50% or more of the conventional DC / DC converter.

As described above, according to the DC / DC converter of the present embodiment, it has a magnetic storage function for making the step-up (step-down) variable, and suppresses noise emission from the input line during switching, It is possible to prevent the influence on the peripheral devices, and the conventional noise filter can be deleted.
Therefore, according to the DC / DC converter of the present embodiment, it is possible to reduce the number of components of the power converter in the electric and electric assist system of the automobile and to reduce the manufacturing cost.

  Each embodiment has been described above, but the present invention is not limited to these embodiments. For example, a fuel cell vehicle (FCV), a hybrid electric vehicle (HEV), an electric vehicle (EV), and solar power generation It can be used for power converters of electric and electric assist system systems such as systems.

10, 20, 21, 22, 30, 31, 32 Energization control unit 25 Magnetic cancellation type transformer (T1)
35 Series capacitor 100, 110 DC / DC converter 200, 210 Magnetic cancellation type DC / DC converter (buck-boost type)
211 Magnetic cancellation type DC / DC converter (unidirectional step-up type)
212 Magnetic cancellation type DC / DC converter (unidirectional step-down type)
300, 310, 320 Switched capacitance type DC / DC converter (buck-boost type)
311 Switched Capacitance Type DC / DC Converter (Unidirectional Boost Type)
312 Switched capacitance type DC / DC converter (unidirectional step-down type)
400, 410 Conventional switched capacitance type DC / DC converter (buck-boost type)
450 DC power supply (manufactured by Takasago)
455 Sample to be measured (DC / DC converter)
460 RF current sensor probe (Schaffner CSP9160)
470 oscilloscope (Yokogawa DL7480)
480 Electronic load device (manufactured by Takasago)
500 Power control unit (PCU)
510 DC / DC converter 520 Noise filter 550 Wiring 600 Battery 1000 Automotive L, L1, L2 Inductor M Mutual inductance C0 Smoothing capacitor C1, C2, C _out capacitor S1, S2, S3, S4 Switch element D1, D2 Diode

Claims (15)

An input unit having a positive electrode side terminal and a negative electrode side terminal, an output unit having a positive electrode side terminal and a negative electrode side terminal, one end connected to the positive electrode side terminal of the input unit, and the other end connected to the negative electrode side of the input unit A smoothing capacitor connected to a terminal, and an energization control unit having a plurality of switch elements provided between the input unit and the output unit, and performs power conversion by switching the plurality of switch elements A DC / DC converter,
The first inductor is
The smoothing capacitor is connected in parallel with the positive side terminal of the input unit, and one end is connected to the positive side terminal of the input unit and the other end is connected to the positive side terminal of the energization control unit. ,
The second inductor is
The smoothing capacitor is connected in parallel with the negative side terminal of the input unit, and one end is connected to the negative side terminal of the input unit and the other end is connected to the negative side terminal of the energization control unit. A DC / DC converter characterized by comprising: The energization control unit includes a first switch element and a second switch element,
The first switch element includes:
One end is connected to the other end of the first inductor, the other end is connected to the positive terminal of the output unit,
The second switch element is
One end is connected to the other end of the first inductor and one end of the first switch element, and the other end is connected to the other end of the second inductor and a negative terminal of the output unit. The DC / DC converter according to claim 1. A magnetic cancellation type DC / DC converter,
A primary winding and a secondary winding are magnetically coupled via a core, connected to a reverse winding with a 1: 1 turns ratio, and the primary winding is connected to the other end of the first inductor. A magnetic canceling type transformer for connecting a common terminal with the secondary winding;
The energization control unit includes a first switch element, a second switch element, a third switch element, and a fourth switch element,
One end of the first switch element is connected to a terminal opposite to the common terminal of the primary winding, and the other end is connected to the other end of the pre-secondary inductor and the negative terminal of the output unit. Connected,
The second switch element has one end connected to a terminal opposite to the common terminal of the primary winding, and the other end connected to a positive terminal of the output unit,
The third switch element has one end connected to the terminal opposite to the common terminal of the secondary winding, and the other end connected to the other end of the second inductor and the negative terminal of the output unit. And
The fourth switch element has one end connected to a terminal opposite to the common terminal of the secondary winding and the other end connected to a positive terminal of the output unit. Item 4. The DC / DC converter according to Item 1. A magnetic cancellation type DC / DC converter,
A primary winding and a secondary winding are magnetically coupled via a core, connected to a reverse winding with a 1: 1 turns ratio, and the primary winding is connected to the other end of the first inductor. A magnetic canceling type transformer for connecting a common terminal with the secondary winding;
The energization control unit includes a first switch element, a first diode, a second switch element, and a second diode,
The first switch element has one end connected to the terminal opposite to the common terminal of the primary winding, and the other end connected to the other end of the second inductor and the negative terminal of the output unit. And
One end of the first diode is connected to a terminal opposite to the common terminal of the primary winding, and the other end is connected to a positive terminal of the output unit.
The second switch element has one end connected to the terminal opposite to the common terminal of the secondary winding, and the other end connected to the other end of the second inductor and the negative terminal of the output unit. And
The second diode has one end connected to a terminal opposite to the common terminal of the secondary winding, and the other end connected to a positive terminal of the output unit. The DC / DC converter according to 1. A magnetic cancellation type DC / DC converter,
A primary winding and a secondary winding are magnetically coupled via a core, connected to a reverse winding with a 1: 1 turns ratio, and the primary winding is connected to the other end of the first inductor. A magnetic canceling type transformer connecting a common terminal with the secondary winding;
The energization control unit includes a first diode, a first switch element, a second diode, and a second switch element,
One end of the first diode is connected to a terminal opposite to the common terminal of the primary winding, and the other end is connected to the other end of the second inductor and a negative terminal of the output unit. ,
One end of the first switch element is connected to a terminal opposite to the common terminal of the primary winding, and the other end is connected to a positive terminal of the output unit.
The second diode has one end connected to the terminal opposite to the common terminal of the secondary winding, and the other end connected to the other end of the second inductor and the negative terminal of the output unit. ,
The second switch element has one end connected to a terminal opposite to the common terminal of the secondary winding and the other end connected to a positive terminal of the output unit. Item 4. The DC / DC converter according to Item 1. A switched capacitance type DC / DC converter,
Further comprising a first capacitor and a second capacitor connected in series between the energization control unit and the output unit,
The energization control unit includes a first switch element, a second switch element, a third switch element, and a fourth switch element,
One end of the first switch element is connected to the other end of the first inductor, and the other end is connected to a positive electrode side of the first capacitor and a positive electrode side terminal of the output unit,
The second switch element has the other end connected to the other end of the first inductor, and one end connected to the negative side of the first capacitor and the positive side of the second capacitor,
The third switch element has one end connected to the other end of the second inductor, and the other end connected to the negative side of the first capacitor and the positive side of the second capacitor,
The other end of the fourth switch element is connected to the other end of the second inductor, and one end is connected to the negative electrode side of the second capacitor and the negative electrode side terminal of the output unit. The DC / DC converter according to claim 1. A switched capacitance type DC / DC converter,
Further comprising a first capacitor and a second capacitor connected in series between the energization control unit and the output unit,
The energization control unit includes a first diode, a first switch element, a second switch element, and a second diode,
One end of the first diode is connected to the other end of the first inductor, and the other end is connected to a positive side of the first capacitor and a positive side terminal of the output unit,
The first switch element has the other end connected to the other end of the first inductor, and one end connected to the negative side of the first capacitor and the positive side of the second capacitor,
The second switch element has one end connected to the other end of the second inductor and the other end connected to the negative side of the first capacitor and the positive side of the second capacitor,
The other end of the second diode is connected to the other end of the second inductor, and the other end is connected to the negative electrode side of the second capacitor and the negative electrode side terminal of the output unit. The DC / DC converter according to claim 1. A switched capacitance type DC / DC converter,
Further comprising a first capacitor and a second capacitor connected in series between the energization control unit and the output unit,
The energization control unit includes a first switch element, a first diode, a second diode, and a second switch element,
One end of the first switch element is connected to the other end of the first inductor, and the other end is connected to a positive electrode side of the first capacitor and a positive electrode side terminal of the output unit,
The other end of the first diode is connected to the other end of the first inductor, and the other end is connected to the negative side of the first capacitor and the positive side of the second capacitor.
The second diode has one end connected to the other end of the second inductor and the other end connected to the negative side of the first capacitor and the positive side of the second capacitor,
The other end of the second switch element is connected to the other end of the second inductor, and one end is connected to the negative electrode side of the second capacitor and the negative electrode side terminal of the output unit. The DC / DC converter according to claim 1. In the first inductor, a first winding that generates a magnetic flux when energized is wound around a first core, and in the second inductor, a second winding that generates a magnetic flux when energized is connected to a second core. Being wound around,
2. The DC / DC converter according to claim 1, wherein the first core and the second core are configured independently.   The DC / DC converter according to claim 9, wherein the first core and the second core each have a gap. The first inductor has a first winding that generates a magnetic flux when energized, and the second inductor has a second winding that generates a magnetic flux when energized,
The first winding and the second winding share a single core in which one closed magnetic circuit is formed so that the magnetic fluxes generated by each other when energized are shared, and are wound around different opposing portions of the core. The DC / DC converter according to claim 1, wherein the DC / DC converter is turned. The DC / DC converter according to claim 11, wherein a gap (gap) is formed in an opposing portion of the core. The first inductor has a first winding that generates a magnetic flux when energized, and the second inductor has a second winding that generates a magnetic flux when energized,
The first winding and the second winding are respectively wound around one core in which two closed magnetic paths are formed so that magnetic fluxes generated when energized mutually strengthen each other,
The core is
A central magnetic leg, and two side magnetic legs provided on both sides of the central magnetic leg,
The first winding is wound around the one side magnetic leg,
The DC / DC converter according to claim 1, wherein the second winding is wound around the other side magnetic leg. The first inductor has a first winding that generates a magnetic flux when energized, and the second inductor has a second winding that generates a magnetic flux when energized,
The first winding and the second winding are respectively wound around one core in which two closed magnetic paths are formed so that magnetic fluxes generated by each other when energized are strengthened,
The core is
A central magnetic leg, and two side magnetic legs provided on both sides of the central magnetic leg,
The first winding and the second winding are wound so as to be stacked on the central magnetic leg,
2. The DC / DC converter according to claim 1, wherein a gap is formed between the central magnetic leg and the side magnetic leg. The first inductor has a first winding that generates a magnetic flux when energized, and the second inductor has a second winding that generates a magnetic flux when energized,
The first winding and the second winding are respectively wound around one core in which two closed magnetic paths are formed so that magnetic fluxes generated by each other when energized are strengthened,
The core is
A central magnetic leg, and two side magnetic legs provided on both sides of the central magnetic leg,
A connecting portion connecting the two side magnetic legs via the central magnetic leg;
2. The DC / DC converter according to claim 1, wherein the first winding and the second winding are wound so as to be stacked on the central magnetic leg with the connecting portion interposed therebetween.

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