JP2018068015A - Power supply device - Google Patents

Abstract

The present invention provides a power supply device configured using two DC power supplies, which can achieve excellent characteristics with a simple configuration that does not require complicated control. [Solution] A first DC power supply 2 and a second DC power supply 3 connected in series, a voltage converter 4 that converts the voltage of the first DC power supply 2 by controlling switch elements S1 and S2, and a second DC power supply. A pair of output terminals 6n and 6p connected to the voltage converter 4 and the opposite pole to the first DC power supply 2 side of the positive and negative poles of the switch elements S1 and S2 are turned on and off. and a control section 8 for controlling. [Selection diagram] Figure 1

Description

  The present invention relates to a power supply device configured using two DC power supplies.

  For example, a power source (DC power source) mounted on a vehicle as a power source for a traveling motor of a hybrid vehicle or an electric vehicle has a large amount of total electric energy that can be discharged (large capacity), an output voltage (load side) A wide variety of advanced performances are required, such as a high supply voltage), a maximum power that can be output, or a large variable range of power that can be output.

  However, at present, it is difficult to realize all or many of these required performances with a single-structure power supply configured by existing capacitors having constant characteristics.

  On the other hand, for example, Patent Documents 1 to 3 propose a power supply device configured by combining two DC power supplies. This power supply apparatus includes a plurality of switch elements so that two DC power supplies can be connected in parallel or in series with a load, and each DC power supply can appropriately boost the voltage of each of the two DC power supplies. A booster circuit is provided for each power supply.

Japanese Patent Laying-Open No. 2015-027225 Japanese Patent Laying-Open No. 2015-050902 JP2015-105045A

  In the power supply devices found in Patent Documents 1 to 3, it is possible to use DC power supplies having different characteristics as the two DC power supplies. For this reason, the power supply apparatus as a whole can realize characteristics that combine the characteristics of two DC power supplies (characteristics that are difficult to achieve with each DC power supply alone).

  However, in the power supply devices found in Patent Documents 1 to 3, a large number of switch elements are required in order to be able to connect two DC power supplies in parallel or in series to the load. For this reason, the on / off control of these switch elements tends to be complicated, and the power loss in these switch elements tends to increase.

  In addition, since each DC power supply includes a booster circuit, the configuration of the power supply device including these booster circuits and a large number of switch elements tends to be large.

  Furthermore, in a situation where two DC power supplies are connected in parallel, it is necessary to suppress the current from one DC power supply to the other DC power supply from affecting each other. In this case, in particular, due to the difference in the characteristics of the two DC power supplies, the control of the booster circuit for each DC power supply is easily complicated or highly accurate.

  The present invention has been made in view of such a background, and is a power supply device configured using two DC power supplies, and a power supply device capable of realizing excellent characteristics with a simple configuration that does not require complicated control. The purpose is to provide.

  Furthermore, it aims at providing the transport equipment provided with this power supply device.

In order to achieve this object, the power supply device of the present invention includes a first DC power supply and a second DC power supply connected in series,
A voltage converter including an inductor and a switch element, and connected to the first DC power supply so as to convert the voltage of the first DC power supply by controlling on / off of the switch element;
A pair of output terminal portions respectively connected to a pole opposite to the pole on the first DC power source side of the positive electrode and the negative electrode of the second DC power source, and the voltage converter;
A control unit for controlling on / off of the switch element,
A composite voltage is generated between the pair of output terminal portions by adding a conversion voltage obtained by converting the voltage of the first DC power supply by the voltage converter to the voltage of the second DC power supply. (First invention).

  In the present invention, “converting the voltage of the first DC power supply” more specifically means generating a voltage in which the magnitude of the voltage is changed from the voltage of the first DC power supply. means. In this case, the conversion of the voltage of the first DC power supply is not limited to step-up, but may include step-down.

  According to the first aspect of the invention, voltage conversion is performed by the voltage converter only for the first DC power source of the first DC power source and the second DC power source.

  For this reason, a power supply suitable for voltage conversion (for example, a power supply with high responsiveness to voltage conversion or a power supply in which deterioration due to voltage conversion hardly occurs) is adopted as the first DC power supply. As such, a power supply that is not suitable for voltage conversion (for example, a power supply that has a large output voltage or capacity but is likely to undergo deterioration due to voltage conversion) may be employed.

  Then, by performing voltage conversion by the voltage converter on the second DC power supply, it is possible to generate various voltages more than the voltage of the first DC power supply between the pair of output terminal portions. It becomes.

  Also, in this case, by using a power source suitable for voltage conversion as the first DC power source, the first DC power source can be switched while maintaining the energization current of the second DC power source below the allowable maximum value during the voltage conversion. It is possible to change the flowing current with a relatively large variable width. As a result, it is possible to increase the change width of the voltage that can be generated between the pair of output terminal portions.

  As described above, power sources having different characteristics can be adopted as the first DC power source and the second DC power source, and characteristics that cannot be obtained only by the first DC power source and the second DC power source can be realized.

  In the power supply device of the present invention, since the voltage converter including the inductor and the switch element is provided only on the first DC power supply side, the voltage converter can be easily configured using relatively few switch elements. The voltage generated between the pair of output terminal portions can be controlled only by controlling on / off of the switch element of the voltage converter.

  Therefore, according to the power supply device of the first invention, excellent characteristics can be realized with a simple configuration that does not require complicated control.

  In the first invention, the voltage converter may be configured as follows, for example. That is, the voltage converter includes a transformer having a first coil and a second coil as the inductor, and a first switch element and a second switch element as the switch elements, and the first of the transformer. A partial coil from one end to the middle of the first coil of the coil and the first switch element are connected in series between a positive electrode and a negative electrode of the first DC power source, and the first of the transformer Of the two coils, a partial coil from one end to the middle of the second coil and the second switch element are connected in series between a positive electrode and a negative electrode of the first DC power source, and the first coil and A configuration in which each other end of the second coil is connected to one output terminal portion of the pair of output terminal portions may be employed. In this case, in the present invention, the control unit is configured to have a function of alternately turning on and off the first switch element and the second switch element (second invention).

  In the second invention, the “intermediate part” of each of the first coil and the second coil means an intermediate part between both ends of each coil. The “intermediate portion” is not limited to a midpoint where the distances between the ends of each coil are equal, and may be a portion closer to one end side or the other end side of the coil. And each "partial coil" of the said 1st coil and the 2nd coil means the coil of the part between the one end of this coil, and the intermediate part among the whole of each coil.

  The first switch element and the second switch element are alternately turned on / off because the first switch element is turned on while the second switch element is turned off, and the first switch element is turned off. It means that the second switch element is turned on alternately.

  According to the second invention, when the first switch element is controlled to be in the on state while the second switch element is in the off state, the partial coil of the first coil that is energized from the first DC power supply, A voltage obtained by boosting the voltage of the first DC power source can be generated by the first coil by mutual induction with the second coil.

  Further, when the second switch element is controlled to be turned on while the first switch element is turned off, mutual induction between the partial coil of the second coil and the first coil causes the first DC power supply to The voltage can be boosted.

  Therefore, the boosted voltage can be generated alternately by the first coil and the second coil. A voltage obtained by adding these boosted voltages to the total voltage of the first DC power supply and the second DC power supply is applied to the pair of output terminal portions.

  For this reason, a highly continuous boosted voltage can be generated between the pair of output terminal portions.

  In the second invention, the number of turns of the first coil and the second coil is set to be the same, and the number of turns of the partial coil of the first coil and the partial coil of the second coil. Are preferably set to be the same (third invention).

  According to this, the boost generated in each of the first coil and the second coil in any situation when the first switch element is turned on and when the second switch element is turned on. The voltage can be made uniform.

  As a result, the stability of the voltage generated between the pair of output terminal portions can be enhanced. In other words, a highly stable voltage (voltage with less ripple) can be supplied from the output terminal portion to the external load.

  The voltage converter can also employ the following configuration. That is, the voltage converter includes a coil as the inductor, one end of the coil is connected to one of the positive electrode and the negative electrode of the first DC power supply, and the other end of the coil is A configuration that is connected to one output terminal portion of the pair of output terminal portions and connected to the other of the positive electrode and the negative electrode of the first DC power supply via the switch element. Can be adopted (fourth invention).

  According to this, electromagnetic energy is stored in the coil by the current flowing from the first DC power source in the coil while the switch element is controlled to be in the ON state. Subsequently, when the switch element is switched to the OFF state, a boosted voltage of the coil is generated, and a voltage obtained by adding the boosted voltage to the sum of the first DC power supply and the second DC power supply is It will be applied to the output terminal part.

  According to this 4th invention, the power supply device of this invention is realizable with a very simple structure. Also, the voltage converter can be easily controlled.

  In the first to third aspects of the invention, the first DC power source and the second DC power source may be constituted by rechargeable capacitors. In this case, it is preferable to further include a charging circuit that charges the first DC power supply with the stored power of the second DC power supply (fifth invention).

  Here, since the first DC power source is a power source that performs voltage conversion by the voltage converter, the first DC power source tends to consume more stored power than the second DC power source.

  However, according to the fifth aspect of the present invention, the charging circuit can appropriately supplement the stored DC power from the second DC power source to the first DC power source. For this reason, it is possible to prevent the stored power of the first DC power supply from being exhausted early.

  In the fifth aspect of the invention, the charging circuit can employ the following configuration, for example. That is, the charging circuit includes a charging coil and a switching element that are a coil and a switching element connected in series between a positive electrode and a negative electrode of the second DC power supply, and both ends of the charging coil are The thing of the structure connected to each of the positive electrode and negative electrode of a 1st DC power supply can be employ | adopted. In this case, the control unit further includes a function of controlling on / off of the charging switch element (a sixth invention).

  According to this, electromagnetic energy is stored in the charging coil that is energized from the second DC power source by controlling the charging switch element to be in an ON state. Subsequently, the first DC power supply is charged by the electromagnetic energy stored in the charging coil by switching the charging switch element to the OFF state. Therefore, according to the sixth aspect of the present invention, the stored DC power of the second DC power supply can be transferred to the first DC power supply via the charging coil to charge the first DC power supply.

  In the sixth aspect of the invention, at least one of the ends of the charging coil has a forward direction from the negative electrode of the first DC power source to the positive electrode of the first DC power source via the charging coil. It is preferable to be connected to the first DC power supply via a diode (seventh invention).

  According to this, it is possible to prevent the first DC power supply from being charged with a reverse polarity. In particular, when the first DC power supply is constituted by, for example, an electric double layer capacitor or the like, it is effective in appropriately protecting the first DC power supply.

  When the fifth invention is applied to the second invention or the third invention, that is, in the second invention or the third invention, the first DC power supply and the second DC power supply are constituted by rechargeable capacitors, respectively. In the case where the charging circuit further includes a charging circuit that charges the first DC power supply with the stored power of the second DC power supply, the charging circuit may employ the following configuration, for example.

That is, the charging circuit includes a charging coil and a switching element that are a coil and a switching element connected in series between a positive electrode and a negative electrode of the second DC power source, and the charging coil includes the second coil During energization from a DC power source, a voltage capable of charging the first DC power source is induced in the partial coil of the one coil by mutual induction with one of the first coil and the second coil of the transformer. The first coil and the second coil are wound around a core wound,
Of the first switch element and the second switch element of the voltage converter, the switch element connected in series to the one coil of the transformer includes a partial coil of the one coil and the second DC power source. It is possible to adopt a configuration in which diodes whose forward direction is the direction in which the charging current of the second DC power supply flows are connected in parallel.

  In this case, the control unit further has a function of controlling on / off of the charging switch element (eighth invention).

  According to this, when the charging switch element is controlled to be in an ON state, the one coil is caused by mutual induction between the charging coil energized from the second DC power source and the one coil of the transformer. The charging current is supplied to the first DC power source through the diode by the voltage induced in the partial coil. Thereby, the first DC power supply can be charged.

  In this case, since the charging coil is wound around the core of the transformer, the charging circuit can be made compact.

In the eighth aspect of the invention, the charging circuit includes a first charging coil and a first charging switch element, a second charging coil and a second charging coil as a set of the charging coil and the charging switch element. Two sets of switch elements, and the first charging coil is electrically connected to the first coil of the transformer upon energization from the second DC power source. The coil is wound around the core so that a voltage capable of charging the first DC power supply is induced in the partial coil, and the second charging coil is connected to the transformer when energized from the second DC power supply. The coil is wound around the core so that a voltage capable of charging the first DC power source is induced in the partial coil of the second coil by mutual induction with the second coil.
The first switch element of the voltage converter is connected in parallel with a diode whose forward direction is the direction in which the charging current of the second DC power supply flows between the partial coil of the first coil and the second DC power supply. The second switching element of the voltage converter has a diode whose forward direction is the direction in which the charging current of the second DC power supply flows between the partial coil of the second coil and the second DC power supply. Are connected in parallel,
The control unit preferably has a function of alternately turning on and off the first charging switch element and the second charging switch element (ninth invention).

  Note that alternately turning on and off the first charging switch element and the second charging switch element means turning on the first charging switch element while turning off the second charging switch element. And turning on the second charging switch element alternately while turning off the first charging switch element.

  According to the ninth aspect, an induced voltage is alternately generated in each of the partial coils of the first coil and the second coil of the transformer, and a charging current is caused to flow to the first DC power source by each induced voltage to 1 DC power supply can be charged.

  For this reason, the first DC power supply can be efficiently charged while continuously generating the charging voltage (the induced voltage) applied to the first DC power supply.

  In particular, in the ninth invention, when the first charging coil and the second charging coil have the same number of turns and the ninth invention is combined with the third invention, the first DC power supply The stability of the charging voltage can be increased.

  In the eighth aspect of the invention, the ratio of the number of turns of the partial coil of the one coil to the number of turns of the charging coil is equal to or greater than the ratio of the full charge voltage of the first DC power supply to the full charge voltage of the second DC power supply. Is preferably set (tenth invention).

  Similarly, in the ninth aspect of the invention, the ratio of the number of turns of the first coil to the number of turns of the first charging coil, and the ratio of the number of turns of the second coil to the second coil of the second coil. It is preferable that the ratio of the number of turns is set to be equal to or greater than the ratio of the full charge voltage of the second DC power supply and the full charge voltage of the first DC power supply (11th invention).

  According to these tenth and eleventh aspects, the number of turns of the charging coil or the first charging coil and the second charging coil can be kept to a minimum. For this reason, the enlargement of the said core and by extension, the enlargement of the said voltage converter and the whole charging circuit can be prevented.

  In the first to eleventh aspects of the invention, the first DC power source is constituted by a capacitor having a higher output density than the second DC power source, and the second DC power source has an energy density higher than that of the first DC power source. It is preferable that the battery is composed of a capacitor (Twelfth Invention).

  According to this, since the second DC power supply has a relatively high energy density, it is possible to use a large amount of stored energy (that is, a large capacity). As a result, the period which can supply electric power to the external load from the power supply device of this invention can be lengthened.

  In addition, this type of second DC power supply is generally difficult to increase the maximum power that can be output, but since the first DC power supply has a relatively high output density, the maximum power that can be output is high. Can be big.

  For this reason, the first DC power supply can add large power to the power of the second DC power supply by voltage conversion (particularly, boosting operation) by the voltage converter. As a result, it is possible to supply large electric power to the external load from the pair of output terminal portions.

  Moreover, the transport apparatus according to the present invention includes the power supply device according to any of the first to twelfth inventions (a thirteenth invention).

  According to this, the transport apparatus which can have the effect demonstrated regarding the said 1st-12th invention is realizable.

The figure which shows the structure of the power supply device of 1st Embodiment of this invention. Operation | movement explanatory drawing of the power supply device of 1st Embodiment. Operation | movement explanatory drawing of the power supply device of 1st Embodiment. The figure which shows the structure of the power supply device of 2nd Embodiment of this invention. Operation | movement explanatory drawing of the power supply device of 2nd Embodiment. The figure which shows the structure of the power supply device of 3rd Embodiment. The figure which shows the structure of the power supply device of 4th Embodiment of this invention.

[First Embodiment]
A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the power supply device 1 </ b> A of the present embodiment generates a converted voltage obtained by converting the magnitude of the voltage V <b> 1 of the first DC power supply 2 and the second DC power supply 3 and the first DC power supply 2. A voltage converter 4; a charging circuit 5 that charges the first DC power supply 2 with the power of the second DC power supply 3; a pair of output terminal portions 6p and 6n that output a power supply voltage Vout to an external load (not shown); In order to smooth the power supply voltage Vout, a smoothing capacitor 7 interposed between the output terminal units 6p and 6n and a control unit 8 for controlling the operation of the voltage converter 4 and the charging circuit 5 are provided.

  This power supply device 1A can be used for various applications. For example, the power supply device 1A can be used as a power supply device for an electric motor (not shown) that is mounted on a hybrid vehicle or an electric vehicle as a transportation device and used as a power source for the vehicle. In this case, power supply from the power supply device 1A to the electric motor as an external load is performed via a motor drive circuit (not shown) such as an inverter.

  Each of the first DC power supply 2 and the second DC power supply 3 is composed of one or more rechargeable capacitors. In this case, capacitors having different characteristics are used as capacitors constituting each of the first DC power supply 2 and the second DC power supply 3.

  For example, in the present embodiment, the first DC power supply 2 is composed of one or more capacitors having a higher output density than the second DC power supply 3, and the second DC power supply 3 has an energy density higher than that of the first DC power supply 2. It is comprised by one or more electrical storage devices with high.

  Here, the output density is the amount of electricity that can be output per unit weight or unit volume of the capacitor (the amount of electric energy per unit time or the amount of charge per unit time), and the energy density is the unit of the capacitor. The amount of electrical energy that can be stored per weight or per unit volume.

  In the present embodiment, for example, an electric double layer capacitor is used as a capacitor constituting the first DC power supply 2 (a capacitor having a high output density). Moreover, as a capacitor | condenser (capacitor with a high energy density) which comprises the 2nd DC power supply 3, a lithium ion battery, a nickel hydride battery, etc. are used, for example.

  In addition, when the 1st DC power supply 2 is comprised by several electrical storage device (cell), this 1st DC power supply 2 is connected in parallel, or series connection, or those combination of the said several electrical storage device. It is the power supply of the structure connected mutually in the connection form. This is the same even when the second DC power supply 3 is constituted by a plurality of capacitors (cells).

  The first DC power source 2 and the second DC power source 3 are connected in series. In the present embodiment, the first DC power supply 2 and the second DC power supply 3 are connected in series so that the negative electrode of the first DC power supply 2 has the same potential (or almost the same potential) as the positive electrode of the second DC power supply 3. ing. Further, the negative terminal of the second DC power supply 3 is electrically connected to the output terminal section 6n so as to have the same potential (or substantially the same potential) as the negative output terminal section 6n of the output terminal sections 6p and 6n. .

  In the present embodiment, the voltage converter 4 is configured to be able to boost the voltage V1 of the first DC power supply 2, and the voltage obtained by boosting the voltage V1 is used as the voltage V2 of the second DC power supply 3. Is connected to the first DC power supply 2 and the positive output terminal portion 6p so as to generate a voltage Vout obtained by addition (superimposition) between the output terminal portions 6p and 6n.

  In this embodiment, the voltage converter 4 includes four switch elements S1 to S4, four free-wheeling diodes D1 to D4 respectively connected in parallel to the switch elements S1 to S4, and two coils C1 and C1 serving as inductors. This is a switching DC / DC converter including a transformer TR1 having C2.

  Each switch element S1-S4 is comprised by semiconductor switch elements, such as IGBT and FET. Each of the free-wheeling diodes D1 to D4 is connected in parallel to each switch element S1 to S4 so that the direction opposite to the energization possible direction of each switch element S1 to S4 is the forward direction. In the following description, each set of the switch elements S1 to S4 and the corresponding diodes D1 to D4 may be referred to as switch units SD1 to SD4, respectively.

  The transformer TR1 is a magnetic cancellation type transformer, and the coils C1 and C2 are wound around the core CR1 so that the magnetic fluxes generated by the respective energizations are opposite to each other. These coils C1 and C2 have the same number of turns.

  The coils C1 and C2 correspond to the first coil and the second coil in the present invention, respectively.

  One end of each of the coils C1 and C2 is connected to the positive electrode so as to have the same potential (or almost the same potential) as the positive electrode of the first DC power supply 2. The other ends of the coils C1 and C2 are connected to the positive output terminal portion 6p via the switch portions SD3 and SD4, respectively.

  The forward direction of each of the free wheel diodes D3 and D4 of the switch portions SD3 and SD4 (the reverse direction of the energization direction of the switch elements S3 and S4) is the direction from the coils C1 and C2 toward the output terminal portion 6p.

  Further, intermediate portions C1a and C2a between both ends of the coils C1 and C2 are connected to the negative electrode of the first DC power supply 2 through the switch portions SD1 and SD2, respectively. The number of turns of the coil C1 from one end on the first DC power source 2 side to the middle part C1a (hereinafter referred to as the input side partial coil of the coil C1) and the middle part C2a from one end of the coil C2 on the first DC power source 2 side The portions up to (hereinafter referred to as the input side partial coil of the coil C2) are the same as each other. The input side partial coils of the coils C1 and C2 correspond to partial coils in the present invention.

  In addition, the energization possible direction (reverse direction of the freewheeling diodes D1 and D2) of the switch elements S1 and S2 of the switch units SD1 and SD2 is the negative electrode of the first DC power supply 2 from the middle portions C1a and C2a of the coils C1 and C2. It is the direction toward.

  Supplementally, each of the coils C1 and C2 may have a structure in which a plurality of coils are connected in series. In this case, in each of the coils C1 and C2, a connecting portion can be used as the intermediate portion between adjacent coils.

  Moreover, in this embodiment, the 1st DC power supply 2 and the 2nd DC power supply 3 can be charged with the regenerative power supplied suitably from the external load (electric motor) side which supplies electric power from the output terminal parts 6p and 6n. In order to do so, the switch elements S3 and S4 of the switch sections SD3 and SD4 are provided. However, when the regenerative power is not charged in the first DC power supply 2 and the second DC power supply 3, the switch elements S3 and S4 may be omitted.

  The charging circuit 5 includes a coil C3 and a switch element S5 connected in series between the positive electrode and the negative electrode of the second DC power supply 3, a free wheeling diode D5 connected in parallel to the switch element S5, and a coil C3 and a switch element S5. And a diode D6 interposed between the node on the current path between and the positive electrode of the first DC power supply 2. Hereinafter, a set of the switch element S5 and the free wheel diode D5 may be referred to as a switch unit SD5. The configuration of the switch unit SD5 is the same as that of each of the switch units SD1 to SD4 of the voltage converter 4.

  The forward direction of the diode D6 is a direction from the coil C3 and the switch element S5 side toward the positive electrode of the first DC power supply 2, and the energizable direction of the switch element S5 of the switch unit SD5 (the reverse direction of the free wheel diode D5) is the coil The direction is from C3 toward the negative electrode of the second DC power supply 3.

  The coil C3 and the switch element S5 of the charging circuit 5 correspond to the charging coil and the charging switch element in the present invention, respectively. The diode D6 corresponds to the diode according to the charging circuit of the present invention.

  The control unit 8 is configured by one or more electronic circuit units including a CPU, a RAM, a ROM, an interface circuit, and the like.

  The control unit 8 executes a process for controlling on / off of each of the switch elements S1 to S5 by a function realized by an installed hardware configuration or a program (software configuration). And in this embodiment, the control part 8 is provided with the voltage conversion control mode which performs operation control of the voltage converter 4, and the charge control mode which performs operation control of the charging circuit 5 as a mode of the control processing to perform.

  The operation of the power supply device A1 will be described below. First, the operation in the voltage conversion control mode will be described. In a situation where electric power is supplied to the external load (in this embodiment, during the power running operation of the electric motor as the external load), the control unit 8 executes the control process in the voltage conversion control mode.

  This control process will be described with reference to FIG. In this control process, the control unit 8 performs control so that the switch elements S1 and S2 are alternately turned on and off. That is, the control unit 8 alternately turns on the switch element S1 while turning the switch element S2 off and alternately turns on the switch element S2 while turning off the switch element S1. The switching elements S1 and S2 are controlled so as to repeat.

  Here, FIG. 2 shows a situation in which, for example, the switch element S1 is turned off and the switch element S2 is turned on.

  In this situation, the current supplied to the external load is supplied from the negative output terminal 6n to the second DC power source 3, the first DC power source 2, and the coil C1 of the transformer TR1, as indicated by the white arrow Y1. The current flows through the diode D3 of the switch part SD3 and the output terminal part 6p on the positive electrode side in order to the external load side. In this case, the supply current to the external load is the same as the energization current (discharge current) of the second DC power supply 3.

  At the same time, as indicated by the white arrow Y2, the positive electrode of the first DC power supply 2 reaches the negative electrode of the first DC power supply 2 via the input side partial coil of the coil C2 and the switch element S2 in the ON state. While the current flows back in the current path, a voltage that coincides with or substantially coincides with the voltage V1 of the first DC power supply 2 is instantaneously applied to the input side partial coil of the coil C2 (see arrow Y3 in FIG. 2).

  At this time, the applied voltage of the input side partial coil of the coil C2 is boosted by α times between both ends of the coil C1 which becomes a current path of the supply current to the external load by mutual induction between the coils C1 and C2. An induced voltage (= α · V1) is generated (see arrow Y4 in FIG. 2).

  Here, α is in accordance with the ratio of the number of turns of the input side partial coil of the coil C2 (= the number of turns of the input side partial coil of the coil C1) and the number of turns of the coil C1 (= the number of turns of the coil C2). The specified coefficient (> 1). That is, α = N / n where N is the number of turns of the coils C1 and C2 (total number of turns) and n is the number of turns of the input side partial coils of the coils C1 and C2.

  Thus, in the situation where the switch element S1 is turned off and the switch element S2 is turned on, an induced voltage (= α · V1) is instantaneously generated in the coil C1.

  The same applies to the situation where the switch element S1 is turned on and the switch element S2 is turned off. In this situation, the current supplied to the external load is supplied from the negative output terminal 6n to the second DC power source 3, the first DC power source 2, the coil C2 of the transformer TR1, the diode D4 of the switch unit SD4, and the positive side. Through the output terminal 6p in order to flow to the external load side.

  At the same time, the current flows back in the current path from the positive electrode of the first DC power supply 2 to the negative electrode of the first DC power supply 2 via the input side partial coil of the coil C1 and the switch element S1 in the ON state. An induced voltage (= α · V1) is instantaneously generated in C2.

  Therefore, in any of the situation where the switch element S1 is turned off and the switch element S2 is turned on, and the switch element S1 is turned on and the switch element S2 is turned off, 1 As shown in FIG. 2, a voltage obtained by boosting the voltage V1 of the first DC power supply 2 (= V1 + α · V1 = (1 + α)) between the negative electrode of the DC power supply 2 and the output terminal portion 6p on the positive electrode side. V1) occurs. Then, a voltage Vout (= (1 + α) · V1 + V2) (or a voltage substantially matching this) obtained by adding this boosted voltage to the voltage V2 of the second DC power supply 3 is generated between the output terminal portions 6p and 6n. The Rukoto. The voltage Vout is smoothed by the smoothing capacitor 7.

  Supplementally, the voltage Vout (= (1 + α) · V1 + V2) is more specifically an instantaneous maximum voltage that can be generated between the output terminal portions 6p and 6n. The voltage obtained by smoothing the voltage Vout by the smoothing capacitor 7 is variably controlled by adjusting the on / off duty of each of the switch elements S1 and S2 or the cycle of alternately switching on and off the switch elements S1 and S2. Is possible.

  According to the operation of the voltage converter 4, the first DC power supply 2 has a supply current to the external load (= the energization current of the second DC power supply 3) for boosting operation in the voltage converter 4, Although a current larger than a current (> current supplied to an external load) combined with the return current passing through the input side partial coils of the coils C1 and C2 flows, the first DC power supply 2 is a capacitor having a high output density. It is made up of.

  For this reason, it is possible to apply a large current with a highly stable voltage while avoiding a sudden voltage drop or deterioration of the first DC power supply 2.

  As a result, even when a large current close to the rated current (maximum allowable current) of the second DC power supply 3 is supplied to the external load, the total voltage of the first DC power supply 2 and the second DC power supply 3 (= V1 + V2) Higher voltage Vout can be output from the output terminal portions 6p and 6n. Therefore, large electric power can be supplied to the external load from the output terminal portions 6p and 6n.

  Further, by alternately switching on and off the switch elements S1 and S2, the induction voltage (= α · V1) is generated in each of the coils C1 and C2, so that the output terminals 6p and 6n The voltage Vout generated between them can be a highly stable voltage with little ripple.

  Moreover, since the 2nd DC power supply 3 is comprised by the electrical storage device with high energy density, the 2nd DC power supply 3 can be used as a high capacity | capacitance power supply. For this reason, it is possible to lengthen the period during which power can be appropriately supplied to the external load (and thus the cruising range of the vehicle).

  Supplementally, when the regenerative power is charged in the first DC power supply 2 and the second DC power supply 3, the control unit 8 switches the switch elements S1 and S2 alternately on and off as described above, and also switches the switch element S3. , S4 are controlled so as to alternately turn on and off.

  In this case, more specifically, in the situation where the switch element S1 is turned on, the switch element S3 is turned off, the switch element S4 is turned on, and the switch element S2 is turned on. Switch elements S1 to S4 are controlled so that the switch element S3 is turned off and the switch element S3 is turned on.

  In this way, the voltage of the regenerative power supplied from the external load side to the output terminal units 6p and 6s is stepped down by the voltage converter 4, and then the first DC power source 2 and the second DC power source 3 are connected. Applied to the series circuit, the first DC power supply 2 and the second DC power supply 3 are charged.

  Next, the operation of the power supply device A1 in the charge control mode will be described with reference to FIGS. 3A and 3B. When the stored power of the first DC power supply 2 decreases to some extent, the control unit 8 executes the control process in the charge control mode.

  In this control process, the control unit 8 controls the switch element S5 such that the switch element S5 of the charging circuit 5 is periodically turned on / off. FIG. 3A shows a situation where the switch element S5 is turned on, and FIG. 3B shows a situation where the switch element S5 is switched from the on state to the off state.

  In the situation where the switch element S5 is in the on state, as shown by the white arrow Y5 in FIG. 3A, the second direct current passes from the positive electrode of the second direct current power source 3 through the coil C3 and the on state switch element S5. Electromagnetic energy is stored in the coil C <b> 3 when the current flows back through the current path reaching the negative electrode of the power source 3.

  Next, in a situation where the switch element S5 is switched to the OFF state, an electromotive force is generated so as to keep current flowing through the coil C3. As a result, as indicated by the white arrow Y6 in FIG. 3B, the current flows from the negative electrode side of the first DC power supply 2 to the positive electrode of the first DC power supply 2 via the coil C3 and the diode D6. Reflux. As a result, the 1st DC power supply 2 is charged with the electromagnetic energy stored in the coil C3.

  In other words, the stored power of the second DC power supply 3 is transferred to the first DC power supply 2 via the coil C3 by repeatedly turning on and off the switch element S5.

  In addition, the charge amount (charge amount per unit time) of the first DC power supply 2 can be controlled by adjusting the on / off duty of the switch element S5.

  Here, since the first DC power supply 2 has an energy density lower than that of the second DC power supply 3, the stored power of the first DC power supply 2 is quickly reduced by the operation of the voltage converter 4 in the step-up control mode. Although it is easy, the stored power can be appropriately supplemented from the second DC power source 3 having a high energy density to the first DC power source 2 by the control process in the charge control mode.

  In addition, since the charging circuit 5 includes the diode D6, the reverse voltage is prevented from being applied to the first DC power supply 2. For this reason, the 1st DC power supply 2 comprised with an electric double layer capacitor can be protected appropriately.

[Second Embodiment]
Next, a second embodiment of the present invention will be described below with reference to FIGS. Note that this embodiment is different from the first embodiment only in a part of the configuration. For this reason, the description of the present embodiment will be focused on matters that are different from the first embodiment, and the description of the same matters as the first embodiment will be omitted.

  As shown in FIG. 4, the power supply device 1 </ b> B of the present embodiment includes the voltage converter 4 having the same configuration as the voltage converter 4 of the first embodiment, but has a configuration different from that of the charging circuit 5 of the first embodiment. A charging circuit 11 is provided. The charging circuit 11 includes two coils C4 and C5 as inductors, two switch elements S7 and S8, and two free-wheeling diodes D7 and D8 respectively connected in parallel to the switch elements S7 and S8. Hereinafter, the combination of the switch elements S7 and S8 of the charging circuit 11 and the corresponding diodes D7 and D8 may be referred to as switch units SD7 and SD8, respectively. The configuration of each of the switch units SD7 and SD8 is the same as that of each switch unit SD1 to SD4 of the voltage converter 4.

  The coil C4 and the switch part SD7 connected in series and the coil C5 and the switch part SD8 connected in series are connected in parallel between the positive electrode and the negative electrode of the second DC power supply 3. In this case, the coils C4 and C5 are connected to the positive side of the second DC power source 3, and the switch portions SD7 and SD8 are connected to the negative side of the second DC power source 3.

  In addition, the energization possible direction (reverse direction of the free wheel diodes D7 and D8) of the switch elements S7 and S8 of the switch units SD7 and SD8 is a direction from the coils C4 and C5 toward the negative electrode of the second DC power supply 3.

  In this embodiment, the coils C4 and C5 are wound around the core CR1 of the transformer TR1 of the voltage converter 4. In this case, in this embodiment, the direction of the magnetic flux generated inside the coil C4 when the coil C4 is energized from the second DC power supply 3 is opposite to the direction of the magnetic flux generated inside the coil C1 of the transformer TR1. The direction of the magnetic flux generated inside the coil C5 when the coil C5 is energized from the second DC power supply 3 is opposite to the direction of the magnetic flux generated inside the coil C2 of the transformer TR1. Thus, the coils C4 and C5 are wound around the core CR1.

  The number of turns of the coils C4 and C5 is the same, and the number of turns is 1 / β times the number of turns of the input side partial coils of the coils C1 and C2 of the transformer TR1 (β will be described later). Is a number.

  In the present embodiment, the control unit 8 is configured to control the switch elements S7 and S8 of the charging circuit 11 configured as described above in the charge control mode.

  The power supply device 1B of the present embodiment is the same as that of the first embodiment except for the matters described above.

  Supplementally, the coil C4, the coil C5, the switch element S7, and the switch element S are respectively used as the first charging coil, the second charging coil, the first charging switch element, and the second charging switch element in the present invention. Equivalent to. In the present embodiment, the diodes D1 and D2 provided in the voltage converter 4 correspond to the diodes related to the charging circuit in the present invention.

  In such a power supply device 1B, the control processing in the boost control mode and the operation of the voltage converter 4 are the same as those in the first embodiment.

  On the other hand, in the charge control mode, the control unit 8 performs control so that the switch elements S7 and S8 of the charging circuit 11 are alternately turned on and off. That is, the control unit 8 alternately turns on the switch element S7 while turning the switch element S8 off, and turns on the switch element S8 while turning off the switch element S7. The switching elements S7 and S8 are controlled so as to repeat.

  Here, FIG. 5 shows a situation where, for example, the switch element S7 is turned on and the switch element S8 is turned off.

  In this situation, as indicated by a white arrow Y7 in FIG. 5, a current path from the positive electrode of the second DC power source 3 to the negative electrode of the second DC power source 3 via the coil C4 and the switch element S7 in the on state. As the current circulates, a voltage that coincides with or substantially coincides with the voltage V2 of the second DC power supply 3 is instantaneously applied to the coil C4 (see arrow Y9 in FIG. 5).

  At this time, by the mutual induction between the coil C4 and the coil C1 of the transformer TR1, an applied voltage of the coil C4 is applied to the input side partial coil of the coil C1 by an induced voltage (= β · V2) that is β times larger. Occurs instantaneously (see arrow Y10 in FIG. 5).

  Here, β corresponds to the ratio of the number of turns of the coil C4 (= the number of turns of the coil C5) and the number of turns of the input side partial coil of the coil C1 (= the number of turns of the input side partial coil of the coil C2). It is a specified coefficient. That is, if the number of turns of each of the coils C4 and C5 is m and the number of turns of the input side partial coils of the coils C1 and C2 is n, β = n / m.

  In this embodiment, the value of the coefficient β is a ratio between the voltage V1 (rated voltage) when the first DC power supply 2 is fully charged and the voltage V2 (rated voltage) when the second DC power supply 3 is fully charged ( = V1 / V2) The ratio of the number of turns m of the coils C4 and C5 to the number of turns n of the input side partial coils of the coils C1 and C2 (= n / m) Is set.

  For this reason, the induced voltage (= β · V2) instantaneously generated in the input side partial coil of the coil C1 is a voltage having the same or almost the same magnitude as the rated voltage of the first DC power supply 2.

  Further, the induced voltage (= β · V2) is a voltage in a direction from the middle portion C1a of the coil C1 toward the first DC power supply 2 as indicated by an arrow Y10 in FIG.

  For this reason, as shown by a white arrow Y8 in FIG. 5, from the one end of the coil C1 on the first DC power supply 2 side, the middle portion of the coil C1 via the first DC power supply 2 and the diode D1 of the switch unit SD1. The current flows back in the current path reaching C1a, and the first DC power supply 2 is charged by this current.

  The same applies to the situation where the switch element S8 is turned on and the switch element S7 is turned off. In this situation, the current flows back in the current path from the positive electrode of the second DC power supply 3 to the coil C5 and the negative electrode of the second DC power supply 3 via the switch element S8 in the ON state, A voltage that coincides with or substantially coincides with the voltage V2 of the DC power supply 3 is instantaneously applied.

  Further, in response to this, an induced voltage (= β · V2) that is β times V2 is generated in the input side partial coil of the coil C2 of the transformer TR1. Then, in accordance with the induced voltage, current flows from one end of the coil C2 on the first DC power supply 2 side to the middle part C2a of the coil C2 via the first DC power supply 2 and the diode D2 of the switch part SD2. Circulates and the first DC power supply 2 is charged by this current.

  Accordingly, the coil element can be used in any of the situation in which the switch element S7 is turned on and the switch element S8 is turned off and the switch element S8 is turned on and the switch element S7 is turned off. The first DC power supply 2 is charged by a current that flows according to the induced voltage generated in the C1 or C2 input side partial coil.

  In other words, by repeatedly turning on and off the switch elements S7 and S8, the stored power of the second DC power source 3 is changed to the first through the coil C4 or C5 and the input side partial coil of the coil C1 or C2. 1 is transferred to the DC power source 2.

  The charge amount (charge amount per unit time) of the first DC power supply 2 is adjusted by adjusting the on / off duty of each of the switch elements S7 and S8 or the cycle of alternately turning on and off the switch elements S7 and S8. It can be controlled.

  As described above, according to the present embodiment, the control process in the charge control mode described above is appropriately performed from the second DC power source 3 having a high energy density to the first DC power source 2 as in the case of the first embodiment. The stored power can be replenished.

  In the present embodiment, the core CR1 of the transformer TR1 is used as a core around which the coils C4 and C5 of the charging circuit 11 are wound. That is, the core CR1 is used as a common component of the voltage converter 4 and the charging circuit 11. For this reason, power supply device 1B can be comprised compactly.

  Further, since the induced voltages are alternately generated in the input side partial coils of the two coils C1 and C2 of the transformer TR1 by using the two coils C4 and C5, the ripple of the current flowing into the first DC power supply 2 And the stability of the current can be increased. For this reason, the fluctuation | variation of the charging current of the 1st DC power supply 2 becomes a thing with few, and progress of deterioration of the capacitor | condenser which comprises this 1st DC power supply 2 can be suppressed as much as possible.

  In the present embodiment, the value of the coefficient β (= n / m) corresponds to the voltage V1 (rated voltage) when the first DC power supply 2 is fully charged and the voltage V2 (full voltage when the second DC power supply 3 is fully charged). The number of turns m of each of the coils C4 and C5 was set so as to match or substantially match the ratio (= V1 / V2) with the (rated voltage). However, the number of turns m of the coils C4 and C5 may be set so that the value of the coefficient β (= n / m) is larger than the voltage ratio (= V1 / V2).

  That is, the number of turns m of the coils C4 and C5 may be smaller than that in the above embodiment. By doing so, the core CR1 of the transformer TR1 can be further reduced in size while allowing the first DC power supply 2 to be charged.

  In the present embodiment, the charging circuit 5 includes two coils C4 and C5 and two switch elements S7 and S8. However, only one set of the set of the coil C4 and the switch element S7 and the set of the coil C5 and the switch element S8 may be provided. In this case, in the charge control mode, by periodically turning on and off the one set of switch elements S7 or S8, by the induced voltage generated in one partial coil of the first coil C1 and the second coil C2, The first DC power supply 2 is charged.

[Third Embodiment]
Next, a third embodiment of the present invention will be described below with reference to FIG. Note that this embodiment is different from the second embodiment only in a part of the configuration. For this reason, the description of the present embodiment will be focused on matters that are different from those of the second embodiment, and description of the same matters as those of the second embodiment will be omitted.

  In the power supply device 1B of the second embodiment, when the first DC power supply 2 and the second DC power supply 3 are charged with regenerative power, the second DC power supply 3 is charged by the voltage induced in the coil C4 or C5. However, the power supply device 1B ′ of the present embodiment is configured to prevent the second DC power supply 3 from being charged.

  More specifically, the power supply apparatus 1B 'further includes a switch unit (hereinafter referred to as a switch unit SD11) in which a switch element S11 that can be controlled by the control unit 8 and a diode D11 are connected in parallel. The configuration of the switch unit SD11 is the same as that of the switch unit SD1 and the like.

  Then, the switch unit SD11 causes a current path to return current between the coils C4 and C5 and the second DC power source 3 (specifically, a series circuit of the coil C4 and the switch unit SD7 from the positive electrode of the second DC power source 3). Or a current path that reaches the negative electrode of the second DC power supply 3 through a series circuit of the coil C5 and the switch part SD8. In the illustrated power supply device 1B ', one end of each of the coils C4 and C5 is connected to the positive electrode of the second DC power supply 3 via the switch part SD11.

  In this case, the forward direction of the diode D11 of the switch unit SD11 (the direction opposite to the energization direction of the switch element S11) is a direction from the second DC power supply 3 toward one end of the coils C4 and C5.

  The configuration of the power supply device 1B 'of the present embodiment is the same as that of the power supply device 1B of the second embodiment except for the matters described above.

  In the power supply device 1B ', normally, the switch element S11 is maintained in the OFF state in a situation where the first DC power supply 2 and the second DC power supply 3 are charged with regenerative power. Thereby, even if an induced voltage is generated in the coils C4 and C5, the charging current is prevented from flowing from the coil C4 or C5 to the second DC power supply 3 by the diode D11 of the switch unit SD11.

  Therefore, when the regenerative power is charged in the first DC power supply 2 and the second DC power supply 3, it is possible to prevent the second DC power supply 3 from being charged by the voltage induced in the coil C4 or C5. Note that the switch element S11 can be turned on in a situation where the second DC power supply 3 is charged with regenerative power arbitrarily.

  Supplementally, the switch part SD11 may be interposed between the switch parts SD7 and SD8 of the charging circuit 11 and the negative electrode of the second DC power supply 3 and the output terminal part 6n.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG. Note that this embodiment is different from the first embodiment only in a part of the configuration. For this reason, the description of the present embodiment will be focused on matters that are different from the first embodiment, and the description of the same matters as the first embodiment will be omitted.

  As shown in FIG. 7, the power supply device 1 </ b> C of the present embodiment includes the charging circuit 5 having the same configuration as the charging circuit 5 of the first embodiment, but has a voltage different from that of the voltage converter 4 of the first embodiment. A converter 13 is provided. The voltage converter 13 includes a coil C6 as an inductor, two switch elements S9 and S10, and two free-wheeling diodes D9 and D10 connected in parallel to the switch elements S9 and S10, respectively.

  Each switch element S9, S10 is comprised by semiconductor switch elements, such as IGBT and FET. The free-wheeling diodes D9 and D10 are connected in parallel to the switch elements S9 and S10 so that the direction opposite to the energizable direction of the switch elements S9 and S10 is the forward direction. Hereinafter, the combination of the switch elements S9 and S10 of the voltage converter 13 and the corresponding diodes D9 and D10 may be referred to as switch units SD9 and SD10, respectively. The configurations of the switch units SD9 and SD10 are the same as those of the switch units SD1 to SD4 of the voltage converter 4 described in the first embodiment.

  The switch parts SD9 and SD10 are connected in series between the negative electrode of the first DC power supply 2 and the output terminal part 6p on the positive electrode side. Note that both the energizable direction of the switch element S9 of the switch unit SD9 (the reverse direction of the freewheeling diode D9) and the energizable direction of the switch element S10 of the switch unit SD10 (the reverse direction of the freewheeling diode D10) are both output terminal units 6p. To the negative electrode of the first DC power supply 2.

  One end of the coil C6 is connected to the positive electrode so as to have the same potential (or almost the same potential) as the positive electrode of the first DC power supply 2. The other end of the coil C6 is connected to a node on the current path between the switch parts SD9 and SD10. In other words, the other end of the coil C6 is connected to the negative electrode of the first DC power supply 2 via the switch part SD9 and to the output terminal part 6p via the switch part SD10.

  In the present embodiment, the control unit 8 is configured to control the switch elements S9 and S10 of the voltage converter 13 configured as described above in the boost control mode.

  The power supply device 1C of the present embodiment is the same as that of the first embodiment except for the matters described above.

  Supplementally, the switch element S10 may be omitted when the first DC power supply 2 and the second DC power supply 3 are not charged with regenerative power.

  In the power supply device 1C, the control process in the charge control mode and the operation of the charging circuit 5 are the same as those in the first embodiment.

  On the other hand, in the boost control mode, the control unit 8 controls the switch element S9 so that the switch element S9 of the voltage converter 13 is periodically turned on and off in the charge control mode.

  In this case, in the situation where the switch element S9 is turned on, the supply current to the external load is supplied from the negative output terminal 6n to the second DC power source 3, the first DC power source 2, the coil C6, and the switch unit SD10. It flows to the external load side through the diode D10 and the output terminal portion 6p on the positive electrode side in order. At the same time, current flows back in a current path from the positive electrode of the first DC power supply 2 to the negative electrode of the first DC power supply 2 via the coil C6 and the switch element S9 in the on state, whereby electromagnetic energy is stored in the coil C6. .

  Next, in a situation where the switch element S9 is switched from the on state to the off state, a voltage directed from the first DC power source 2 side to the switch unit SD10 side is induced in the coil C6, so that the negative electrode of the first DC power source 2 is obtained. A voltage (> V1) generated by boosting the voltage V1 of the first DC power supply 2 is generated between the output terminal portion 6p on the positive electrode side. A voltage Vout (> V1 + V2) obtained by adding this boosted voltage to the voltage V2 of the second DC power supply 3 is generated between the output terminal portions 6p and 6n.

  As a result, a voltage Vout higher than the total voltage (= V1 + V2) of the first DC power supply 2 and the second DC power supply 3 is generated between the output terminal portions 6p and 6n.

  The voltage Vout (smoothed voltage) between the output terminal portions 6p and 6n can be variably controlled by adjusting the on / off duty of the switch element S9.

  According to the operation of the voltage converter 13, the first DC power supply 2 is supplied with the current supplied to the external load (= second DC) in the ON state of the switch element S 9 for the boosting operation in the voltage converter 13. Although a current larger than the energization current of the power supply 3 flows, the first DC power supply 2 is composed of a capacitor having a high output density, and therefore, a rapid voltage drop or deterioration of the first DC power supply 2 occurs. A large current can be applied while avoiding this.

  As a result, as in the first embodiment, the first DC power source 2 and the second DC power source 3 can be used even when a large current close to the rated current (maximum allowable current) of the second DC power source 3 is supplied to the external load. The voltage Vout higher than the sum total voltage (= V1 + V2) can be output from the output terminal portions 6p and 6n.

  Further, since the step-up operation can be performed only by the on / off control of the switch element S9, the voltage converter 13 can be made small and have a simple configuration, and the step-up operation can be realized by a simple control process. .

  In the actual embodiments described above, the power supply apparatuses 1A to 1C configured to connect the negative electrode of the first DC power supply to the positive electrode of the second DC power supply 3 are shown. However, a power supply device in which the positive electrode of the first DC power supply is connected to the negative electrode of the second DC power supply 3 can also be configured. In this case, of the output terminal parts 6p and 6n, the positive output terminal part 6p is connected to the positive electrode of the second DC power supply 3, and the negative output terminal part 6n is connected to the voltage converter 4 or 13. The Rukoto.

1A, 1B, 1B ', 1C ... power supply device, 2 ... first DC power supply, 3 ... second DC power supply, 4, 13 ... voltage converter, 5, 11 ... charging circuit, S1, S2, S5, S7, S8 , S9: switch element, TR1: transformer, C1, C2, C3, C4, C5, C6: coil (inductor), CR1: core, D6, D1, D2: diode.

Claims (13)

A first DC power source and a second DC power source connected in series;
A voltage converter including an inductor and a switch element, and connected to the first DC power supply so as to convert the voltage of the first DC power supply by controlling on / off of the switch element;
A pair of output terminal portions respectively connected to a pole opposite to the pole on the first DC power source side of the positive electrode and the negative electrode of the second DC power source, and the voltage converter;
A control unit for controlling on / off of the switch element,
A composite voltage is generated between the pair of output terminal portions by adding a conversion voltage obtained by converting the voltage of the first DC power supply by the voltage converter to the voltage of the second DC power supply. A power supply device characterized by that. The power supply device according to claim 1, wherein
The voltage converter includes a transformer having a first coil and a second coil as the inductor, and a first switch element and a second switch element as the switch elements,
Of the first coil of the transformer, a partial coil from one end to the middle of the first coil and the first switch element are connected in series between a positive electrode and a negative electrode of the first DC power supply. ,
Of the second coil of the transformer, a partial coil from one end to the middle of the second coil and the second switch element are connected in series between the positive electrode and the negative electrode of the first DC power supply. ,
The other end of each of the first coil and the second coil is connected to one output terminal portion of the pair of output terminal portions,
The control unit is configured to have a function of alternately turning on and off the first switch element and the second switch element. The power supply device according to claim 2, wherein
The number of turns of each of the first coil and the second coil is set to be the same, and the number of turns of the partial coil of the first coil and the partial coil of the second coil are set to be the same. A power supply device characterized by that. The power supply device according to claim 1, wherein
The voltage converter includes a coil as the inductor, and one end of the coil is connected to one of a positive electrode and a negative electrode of the first DC power supply, and the other end of the coil is the pair. A power source connected to one of the output terminal portions of the first DC power source and the other of the positive and negative electrodes of the first DC power source via the switch element. apparatus. The power supply device according to any one of claims 1 to 3,
Each of the first DC power source and the second DC power source is constituted by a rechargeable battery,
The power supply apparatus further comprising a charging circuit that charges the first DC power supply with the stored power of the second DC power supply. The power supply device according to claim 5, wherein
The charging circuit includes a charging coil and a charging switch element which are a coil and a switching element connected in series between a positive electrode and a negative electrode of the second DC power source, and both ends of the charging coil are connected to the first coil. Connected to each of the positive and negative electrodes of the DC power supply,
The control unit further includes a function of controlling on / off of the charging switch element. The power supply device according to claim 6, wherein
At least one of both ends of the charging coil is connected to the first through a diode whose forward direction is from the negative electrode of the first DC power source to the positive electrode of the first DC power source via the charging coil. 1 A power supply device connected to a DC power supply. The power supply device according to claim 2 or 3,
Each of the first DC power source and the second DC power source is constituted by a rechargeable battery,
A charge circuit for charging the first DC power supply with the stored power of the second DC power supply;
The charging circuit includes a charging coil and a switching element that are a coil and a switching element connected in series between a positive electrode and a negative electrode of the second DC power source, and the charging coil includes the second DC power source. When energizing, a voltage capable of charging the first DC power source is induced in the partial coil of the one coil by mutual induction with the first coil and the second coil of the transformer. As described above, the first coil and the second coil are wound around the core wound,
Of the first switch element and the second switch element of the voltage converter, the switch element connected in series to the one coil of the transformer includes a partial coil of the one coil and the second DC power source. A diode having a forward direction in which the charging current of the second DC power supply flows is connected in parallel,
The control unit further includes a function of controlling on / off of the charging switch element. The power supply device according to claim 8, wherein
The charging circuit includes a set of a first charging coil and a first charging switch element, and a second charging coil and a second charging switch element as a set of the charging coil and charging switch element. The first charging coil is provided with the first coil to the partial coil of the first coil by mutual induction with the first coil of the transformer when energized from the second DC power source. The coil is wound around the core so as to induce a voltage capable of charging a DC power supply, and the second charging coil is connected to the second coil of the transformer when energized from the second DC power supply. Wound around the core so that a voltage capable of charging the first DC power source is induced in the partial coil of the second coil by mutual induction;
The first switch element of the voltage converter is connected in parallel with a diode whose forward direction is the direction in which the charging current of the second DC power supply flows between the partial coil of the first coil and the second DC power supply. The second switching element of the voltage converter has a diode whose forward direction is the direction in which the charging current of the second DC power supply flows between the partial coil of the second coil and the second DC power supply. Are connected in parallel,
The control unit has a function of alternately turning on and off the first charging switch element and the second charging switch element. The power supply device according to claim 8, wherein
The ratio of the number of turns of the partial coil of the one coil to the number of turns of the charging coil is set to be equal to or higher than the ratio of the full charge voltage of the first DC power supply to the full charge voltage of the second DC power supply. A power supply characterized by. The power supply device according to claim 9, wherein
The ratio of the number of turns of the partial coil of the first coil to the number of turns of the first charging coil and the ratio of the number of turns of the partial coil of the second coil to the number of turns of the second charging coil are respectively The power supply device is set to be equal to or greater than a ratio of a full charge voltage of the second DC power supply and a full charge voltage of the first DC power supply. The power supply device according to any one of claims 1 to 11,
The first DC power source is constituted by a capacitor having a higher output density than the second DC power source, and the second DC power source is constituted by a capacitor having an energy density higher than that of the first DC power source. Power supply. A transportation device comprising the power supply device according to claim 1.