JP5796414B2 - Voltage converter - Google Patents

Description

  The present invention relates to a voltage conversion device that converts the magnitude of an input voltage and outputs it as an output voltage.

  In recent years, motor drive devices that use secondary batteries (batteries) have become widespread in electric vehicles and the like, and step-up DCDC converters that boost the voltage of the battery to the voltage required by the motor drive device have become widely used. Yes. This type of step-up DC / DC converter is strongly required to have a small size and light weight and a high step-up ratio.

  Miniaturization and weight reduction are important because it is necessary to store the device in a limited space in an in-vehicle environment. The high step-up ratio is important because motors such as electric vehicles have a wide operating range from high speed rotation to low speed rotation. In order to realize motor driving in a wide operating range, it is necessary to apply a voltage that overcomes the counter electromotive voltage generated in a wide range from low voltage to high voltage, so the applied voltage can be changed greatly according to the counter electromotive voltage. It will be necessary. On the other hand, in general, it is easy to realize a low boost ratio in a boost converter, but it is often difficult to realize a high boost ratio, so how to achieve a high boost ratio in generating a wide range of drive voltages. Is a problem. Hereinafter, this will be described using a known DCDC converter shown in FIG.

  The step-up DCDC converter shown in FIG. 14 includes a series connection body of a reactor L and a switching element SW connected in parallel to the battery 10, and a diode having a forward direction from the connection point of the series connection body to the output capacitor 12. D. The boosting operation of this converter is as follows.

  First, the switching element SW is turned on to store energy in the reactor L. Here, the current flowing through the reactor L gradually increases at a speed of Vin / L using the inductance L and the input voltage Vin. Thereafter, the energy stored in the reactor L is output to the output capacitor 12 via the diode D by turning off the switching element SW. At this time, the current flowing through the reactor L gradually decreases at a speed of | Vin−Vout | / L using the output voltage Vout or the like. Here, using the time ratio D of the on-time with respect to one cycle of the switching element SW, it is assumed that the gradually increasing amount and the gradually decreasing amount of the current of the reactor L in one cycle of the switching element SW coincide with “D · Vin / L + {(1-D) · (Vin−Vout) / L} = 0 ”is established. As a result, the output voltage Vout is determined to be “Vin / (1-D)”.

  In this case, theoretically, the output voltage Vout can be increased by increasing the duty ratio D. However, in practice, the efficiency decreases as the output voltage Vout increases. This is because the ratio of the switching period of the switching state to the output period of the energy stored in the reactor L increases as the time ratio D increases. For this reason, when the step-up DCDC converter is used, there is a great restriction on increasing the output voltage.

  Therefore, conventionally, as can be seen, for example, in Patent Document 1 below, there has been proposed one that realizes a high step-up ratio by adding a transformer having three coils in addition to a reactor.

JP 2009-95146 A

  However, the above prior art has the following problems with respect to reduction in size and weight.

  First, there is a problem that a transformer is added as compared with the known converter shown in FIG. In general, most of the physique and weight of the electronic components constituting the power converter are occupied by passive components such as capacitors and reactors. Therefore, the addition of a transformer, which is a passive component, inevitably creates a physique increase that cannot be ignored, and prevents miniaturization and weight reduction.

  Second, a large number of turns is required for one of the three coils of the transformer. That is, for example, in order to obtain a step-up ratio that is twice that of the known converter shown in FIG. 14 near the duty ratio D = 0.5, the number of turns of the coil is set to twice the number of turns of the other coils. It is necessary to. This increases the number of turn wires that circulate around the transformer, which not only increases the size of the transformer's magnetic core, but also increases the copper loss of the coil and lowers the power conversion efficiency. May be required, which may increase the size of the cooler.

  The present invention has been made in the process of solving the above-described problems, and an object of the present invention is to provide a new voltage conversion device that converts the magnitude of an input voltage and outputs it as an output voltage.

  Hereinafter, means for solving the above-described problems and the operation and effect thereof will be described.

A first invention is a voltage converter for converting the magnitude of an input voltage and outputting the output voltage as an output voltage, wherein the input voltage is applied to a pair of terminals to which the input voltage is applied and the output voltage is applied. In addition, a pair having the first voltage, which is one of the three voltages of the input voltage, the output voltage, and the differential voltage between the input voltage and the output voltage, as a differential pressure between the pair of terminals. A first voltage application terminal, a pair of terminals to which the input voltage is applied, and a terminal to which the output voltage is applied, and the input voltage, the output voltage, and the input voltage and A pair of second voltage application terminals having a differential voltage between the pair of terminals, the second voltage being one of the three voltages of the differential voltage of the output voltage other than the first voltage; Magnetically coupled When the first voltage is applied to both ends of one of the pair of coils connected in series via the first voltage application terminal, the pair of coils is connected via the connection point of the pair of coils. Separating means for preventing current from flowing between one and the other of the coils, and coupling means for applying the second voltage to both ends of the series connection body of the pair of coils via the second voltage application terminal. A pair of periods of applying a first voltage to the one coil and a period of applying the second voltage to the pair of coils, a direct current that links the one coil in any one of the periods Set to increase the magnetic flux and decrease the DC magnetic flux in the other period, and include two sets of the pair of coils, and the one coil for each set is the first coil, In the case of two coils, the other coil is a third coil shared by the two sets, and a loop path that links both the first coil and the third coil and is guided by a magnetic core; In addition, there are different loop paths that are linked to each other by the second coil and the third coil and guided by the magnetic core.

  The energy stored in the loop path during the period of increasing the DC magnetic flux is released to the outside during the period of decreasing the DC magnetic flux. In the voltage conversion circuit using such a phenomenon, the magnitude of the output voltage is determined based on the relationship that the increase amount and the decrease amount of the DC magnetic flux are equal. Here, the increasing speed and decreasing speed of the DC magnetic flux change in accordance with the number of turns of the coil to which the voltage is applied, in addition to the absolute values of the first voltage and the second voltage. In the above invention, in view of this point, the DC magnetic flux is changed between at least a part of the period in which the DC magnetic flux is increased and at least a part of the period in which the DC magnetic flux is decreased by including the separating unit and the coupling unit. Therefore, the number of turns of the coil to which the voltage is applied is changed. Thereby, the freedom degree of adjustment of the increase rate and reduction | decrease speed of DC magnetic flux can be improved, and the freedom degree for adjusting an output voltage can be improved by extension.

  Further, in the above invention, at least two pairs of coils are provided, and the other coil of the two sets is shared as the third coil. As a result, the ripples generated by each of the two sets of coils can be set to cancel each other, so the current ripple can be reduced compared to the case of one set while suppressing an increase in the number of parts. Can be made easier.

According to a second invention, in the first invention, when a current flows through the pair of coils when the second voltage is applied to the pair of coils, the magnetic flux induced by each of the pair of coils It is characterized in that it is set so that directions in a loop path that links both of the pair of coils are equal to each other.

  When the current is passed through both of the pair of coils by applying the second voltage, when the above directions are opposite to each other, the magnetic flux change in the loop path caused by applying the voltage to both ends of the pair of coils is This is the same as the magnetic flux change that occurs when the second voltage is applied to a single coil having a smaller number of turns than the first coil. This is to change the DC magnetic flux by using one coil when the first voltage is applied and by using a coil having a turn number smaller than the total number of turns of the pair of coils when the second voltage is applied. Is equivalent to For this reason, depending on a use, there exists a possibility that many windings may be needed in order to earn the number of turns. In contrast, in the above invention, the DC magnetic flux is changed by one coil when the first voltage is applied and by using the coil having the total number of turns of the pair of coils when the second voltage is applied. Therefore, it is not necessary to earn extra turns and it is easy to reduce the consumption of each coil material.

According to a third invention, in the first or second invention, when the first voltage is applied to the first coil, a magnetic flux generated in the first coil interlinks the third coil, and the second The magnetic flux generated in the second coil when the first voltage is applied to the coil is set to be opposite to the direction in which the third coil is linked .

  In the above invention, when the loop path that links both the first coil and the third coil and the loop path that links both the second coil and the third coil, the magnetic cores constituting both of these are integrated. For example, the magnetic core can be reduced in size.

According to a fourth invention, in any one of the first to third inventions, the second voltage is applied to the second coil and the third coil by the coupling means, and the first voltage is applied to the first coil. A state in which a voltage is applied; and a state in which the second voltage is applied to the first coil and the third coil by the coupling means and the first voltage is applied to the second coil. It is a characteristic.

  When the second voltage is applied to the second coil and the third coil when the first voltage is applied to the first coil, the current flowing through the first coil is only the number of turns of the first coil or the first voltage. Is not determined and is affected by the current flowing through the third coil. Therefore, for example, when the first voltage is applied to the first coil and the DC magnetic flux that links the first coil gradually increases, the magnetic flux induced by the current flowing through the third coil links the first coil. If the direction is opposite to the DC magnetic flux, it is possible to increase the current flowing through the first coil and thus increase the input energy storage speed. In addition, for example, when the second voltage is applied to the first coil and the third coil and the DC magnetic flux that links the first coil gradually increases, the magnetic flux induced by the current flowing through the third coil links the first coil. If the direction to be made is the same direction as the DC magnetic flux, it is easy to reduce the current flowing through the first coil, and thus to reduce the input energy storage speed.

In a fifth aspect based on the fourth aspect , the separating means and the coupling means are means for connecting the first coil and the third coil, and the current from the first coil to the third coil. A first rectifying means for permitting a flow and preventing a current flow in a reverse direction; and a connecting means for connecting the second coil and the third coil, wherein the current from the second coil to the third coil A second rectifying means for allowing a flow and preventing a reverse current flow; and allowing a current flow from the output side of the first rectifying means to the second voltage application terminal and in a reverse direction. A third rectifier for blocking current flow, and a fourth rectifier for allowing current flow from the output side of the second rectifier to the second voltage application terminal and blocking reverse current flow. Means, the first coil and the first voltage marking A first coil for opening and closing means for opening and closing between the use terminals, characterized in that it comprises a second coil for opening and closing means for opening and closing between said second coil and said first voltage supply terminal.

According to a sixth aspect based on the fourth aspect , the separating means and the coupling means include a first opening / closing means for electrically opening and closing the first coil and the third coil, the second coil, and the second coil. A second opening / closing means for electrically opening / closing between the three coils, a third opening / closing means for opening / closing between one end of the third coil and the second voltage application terminal, and the other of the third coil. A fourth opening / closing means for opening / closing between the end portion and the second voltage application terminal; and allowing a current to flow from the low potential side to the high potential side of the first voltage application terminal via the first coil. And rectifying means for the first coil for preventing the flow in the reverse direction, and allowing the current to flow from the low potential side to the high potential side of the first voltage application terminal via the second coil. The second carp that prevents it from flowing in the opposite direction Characterized in that it comprises a use rectifying means.

According to a seventh invention, in the fourth invention, the separating means and the coupling means are a first opening and closing means for electrically opening and closing the first coil and the third coil, the second coil and the second coil. A second opening / closing means for electrically opening / closing between the three coils, a third opening / closing means for opening / closing between one end of the third coil and the second voltage application terminal, and the other of the third coil. A fourth opening / closing means for opening / closing between the end portion and the second voltage application terminal; a first coil opening / closing means for opening / closing the first coil and the first voltage application terminal; the second coil; And a second coil opening / closing means for opening / closing between the first voltage application terminals.

According to an eighth invention, in any one of the third to seventh inventions, a loop path that links both the first coil and the third coil, and both the second coil and the third coil. Each of the interlaced loop paths includes a magnetic core, and includes a portion having a lower magnetic permeability than other portions.

  A magnetic core that stores energy by increasing the DC magnetic flux and releases energy by decreasing the DC magnetic flux is required to store a large amount of energy, and thus is likely to cause magnetic saturation. In view of this point, the above invention has a portion with low magnetic permeability.

According to a ninth aspect , in the eighth aspect , a magnetic core that configures a loop path that links the first coil and the third coil, and a loop path that links the second coil and the third coil are configured. And a portion having a low magnetic permeability includes a loop path that links both the first coil and the third coil, and a link between both the second coil and the third coil. It is comprised in parts other than a common part with the loop path | route to perform.

  For example, when the direct-current magnetic flux that links the first coil increases, the direction of the magnetic flux interlinks the third coil, and when the direct-current magnetic flux that links the second coil increases, the magnetic flux When the direction of interlinkage is set in the opposite direction, the magnetic flux is canceled out at the common part. Therefore, even if a part with low permeability is provided here, the energy that can be stored is increased. Is difficult. In the said invention, it was set as the said setting in view of such a point.

According to a tenth aspect of the present invention, in any one of the third to ninth aspects, the numbers of turns of the first coil and the second coil are set to be equal to each other, and both the first coil and the third coil And a loop path that links both the second coil and the third coil have the same magnetoresistance.

  In the above invention, the realization of the symmetry between the direct current magnetic flux interlinking the first coil and the direct current magnetic flux interlinking the second coil, and the realization of the symmetry between the current flowing through the first coil and the current flowing through the second coil. Becomes easy.

In an eleventh aspect based on the tenth aspect , an application period of the first voltage by the first voltage application terminal to the first coil and the first voltage application terminal to the second coil. The application period of the second voltage by the second voltage application terminal to the first coil is the same as the application period of the first voltage, and the second voltage application terminal to the second coil The application period of the second voltage is the same.

  In the said invention, the electric current which flows into each of a 1st coil and a 2nd coil can be made the same. Also, when the DC magnetic flux that links the first coil increases, the direction of this magnetic flux interlinking with the third coil, and when the DC magnetic flux that links the second coil increases, this magnetic flux In the case where the direction of interlinkage is set in the opposite direction, the magnetic flux interlinking the third coil can be used as an alternating magnetic flux, so that this portion of the magnetic core can be reduced in size.

In a twelfth aspect based on the eleventh aspect , the application period of the first voltage by the first voltage application terminal to the first coil and the first voltage application terminal to the second coil. The phase with the application period of one voltage is shifted by π.

  In the said invention, the absolute value of each change rate of the direct current magnetic flux which links the 1st coil and the direct current magnetic flux which links the 2nd coil can be reduced as much as possible, and the power loss by a magnetic core can be reduced by extension. Moreover, in the said invention, since the change of the synthetic magnetic flux of the magnetic flux of a 1st coil and the magnetic flux of a 2nd coil can be reduced as much as possible, it also becomes possible to reduce a ripple of an electric current.

In a thirteenth aspect of the present invention based on any one of the third to twelfth aspects of the present invention, a magnetic core that forms a loop path that links both the first coil and the third coil, the second coil, and the third coil. A magnetic core that constitutes a loop path that links both of the coils is integrally formed.

  In the above invention, it is possible to reduce the size of the magnetic component by integrally forming the magnetic cores constituting the pair of loop paths.

In a fourteenth aspect based on the thirteenth aspect , the magnetic core is a loop path that does not link the first coil, the second coil, and the third coil, and a loop path that links a pair of coils. The pair of coils induce magnetic fluxes having the same direction and size on the loop path that links them.

  In the above-described invention, the magnetic component can be reduced in size by integrally forming the magnetic core of the coil for voltage conversion processing and the magnetic core of the pair of coils for performing other processing.

In a fifteenth aspect based on the fourteenth aspect , the magnetic core is a loop path that does not link coils, and constitutes a loop path that sandwiches the first coil, the second coil, and the third coil. It is characterized by.

  In the said invention, the function of a magnetic shield can be given to the loop path | route which pinches | interposes said 1st coil, said 2nd coil, and said 3rd coil.

According to a sixteenth aspect of the present invention, in any one of the third to eighth and tenth to twelfth aspects, the magnetic core constituting a loop path that links both the first coil and the third coil, and the second coil And the magnetic core which comprises the loop path | route which links both said 3rd coils is a different magnetic core, It is characterized by the above-mentioned.

  In the above invention, the pair of magnetic cores can be constituted by a toroidal core or the like.

1 is a system configuration diagram according to a first embodiment. FIG. The time chart which shows the switching control concerning the embodiment. FIG. 3 is a circuit diagram showing a boosting operation according to the embodiment. The circuit diagram which shows the converter concerning 2nd Embodiment. The circuit diagram which shows the converter concerning 3rd Embodiment. The circuit diagram which shows the converter concerning 4th Embodiment. The circuit diagram which shows the converter concerning 5th Embodiment. The time chart which shows the switching control concerning the embodiment. The system block diagram concerning 6th Embodiment. The time chart which shows the switching control concerning the embodiment. The system block diagram concerning 7th Embodiment. The figure for demonstrating the modification concerning the said embodiment. The circuit diagram which shows the converter concerning the modification of each said embodiment. The circuit diagram which shows the conventional converter.

<First Embodiment>
Hereinafter, a first embodiment in which a power conversion device according to the present invention is applied to a power conversion device that converts the voltage of an in-vehicle high-voltage battery will be described with reference to the drawings.

  The illustrated high voltage battery 10 supplies electric power to the in-vehicle main unit, and has a terminal voltage of 100 V or more, for example. The non-insulated converter CNV converts the terminal voltage (input voltage Vin) of the high voltage battery 10 and outputs it as the terminal voltage (output voltage Vout) of the output capacitor 12. The actual input voltage of converter CNV is the terminal voltage of smoothing capacitor 14 connected in parallel to high voltage battery 10. Here, the smoothing capacitor 14 is a means for suppressing fluctuations in the input voltage when the wiring from the high voltage battery 10 to the converter CNV is long. In the figure, the ground symbol may be a reference potential of a high-voltage system system that is insulated from the vehicle body.

  In the converter CNV according to the present embodiment, a pair of terminals on the positive electrode side and negative electrode side (ground side) of the smoothing capacitor 14 (high voltage battery 10) are input terminals to which an input voltage is applied, and the positive electrode of the output capacitor 12 A pair of terminals on the side and the negative side (ground side) are output terminals to which an output voltage is applied. Hereinafter, the configuration of converter CNV will be described in detail.

  A pair of coils W1, W2 is connected to the positive electrode side of the smoothing capacitor 14, and each of the coil W1 and the coil W2 is grounded via the switching element Sa and the switching element Sb (on the negative electrode side). Connected to the input and output terminals). Moreover, each of the coil W1 and the coil W2 is connected to the positive electrode side of the output capacitor 12 via the diodes D1 and D3 and the diodes D2 and D4. The coil W1 is connected to one terminal of the coil W3 via the diode D1, and the coil W2 is connected to the other terminal of the coil W3 via the diode D2.

  A magnetic core (core 20) is linked to the coils W1, W2, and W3. The core 20 is an EE core including three magnetic cores (legs 21, 22, and 23) parallel to each other and connection portions 24 and 25 that are connected to both ends of the cores. Specifically, the left portion of the connecting portion 24 in the drawing is connected to the coil W1, the right portion is connected to the coil W2, and the foot 22 of the core 20 is connected to the coil W3. I have a relationship.

  A low magnetic permeability member Lμ having a lower magnetic permeability than the core 20 is sandwiched between the legs 21 and 23 of the core 20. Here, the low magnetic permeability member Lμ may be formed of, for example, resin or plastic. On the other hand, the legs 21 and 23 have the same shape and dimensions, and the low permeability members Lμ of the legs 21 and 23 also have the same shape and dimensions. This is a setting for equalizing the magnetic resistances of the loop path that links both the coil W1 and the coil W3 and the loop path that links both the coil W2 and the coil W3. Further, the number of turns of the coil W1 (number of turns N1) and the number of turns N2 of the coil W2 are the same (number of turns N). The number of turns is a value obtained by dividing the interlinkage magnetic flux of the coil by the magnetic flux in the coil.

  The control device 30 outputs the operation signals msa and msb to the switching elements Sa and Sb, thereby operating the switching elements Sa and Sb to perform a boosting process. FIG. 2 shows the switching control according to the present embodiment.

  Specifically, FIG. 2 (a1) and FIG. 2 (a2) show the transition of the operation signal msa, and FIG. 2 (b1) and FIG. 2 (b2) show the transition of the operation signal msb. 2 (a1) and FIG. 2 (b1) show the ratio of the time when each switching element Sa, Sb is turned on with respect to the period T when each switching element Sa, Sb is turned on once (duty ratio D). 2 is equal to or less than “0.5”, and FIGS. 2A2 and 2B2 are cases where the duty ratio D is set to be larger than “0.5”. Incidentally, in the present embodiment, the switching element Sa and the switching element Sb set the duty ratio D equal to each other. In the present embodiment, the boosting process is performed by alternately turning on the switching element Sa and the switching element Sb.

  Hereinafter, the relationship between the duty ratio D and the output voltage Vout when the duty ratio D is 0.5 or less is derived with reference to FIG. In FIG. 3, the directions of the magnetic fluxes φ1, φ2, and φ3 are defined as positive. For this reason, the following formula (c1) is established.

φ1 = φ2 + φ3 (c1)
FIG. 3A shows a state in which the switching element Sa is turned on and the switching element Sb is turned off. In this case, when the input voltage Vin is applied to the coil W1, current flows through the path of the input terminal on the positive electrode side (terminal of the smoothing capacitor 14), the coil W1, and the switching element Sa as indicated by a broken line in the figure. Flowing. As a result, the magnetic flux φ1 interlinking the coil W1 gradually increases while being proportional to the input voltage Vin and inversely proportional to the number of turns N1 of the coil W1.

  When the magnetic flux φ1 gradually increases, the magnetic flux φ3 that links the coil W3 also increases gradually. Thereby, according to the Lenz rule, an electromotive force is generated in the coil W3 so as to flow a current in a direction that prevents the magnetic flux φ3 from increasing. For this reason, the diodes D2 and D3 are turned on, and as shown by a one-dot chain line in the figure, the positive-side input terminal (terminal of the smoothing capacitor 14), the coil W2, the diode D2, the coil W3, the diode D3, and the positive electrode Current flows through the path of the output terminal on the side (terminal of the output capacitor 12). At this time, the magnetic flux generated by the current flowing through the coil W2 and the magnetic flux generated by the current flowing through the coil W3 are the loop paths that link the coil W2 and the coil W3 (of the legs 22, 23 and the connecting portions 24, 25). The route is configured so as to be in the same direction in a route that includes a corresponding portion between the feet 22 and 23. The “magnetic flux generated by the current flowing through the coil W3” here is a magnetic flux in the direction opposite to the illustrated magnetic flux φ3.

  Here, in view of the fact that the turns N1 and N2 of the coils W1 and W2 are the common turn N as described above, and using the turn N3 of the coil W3, the following equation is established.

Ndφ1 / dt = Vin (c2)
−N3dφ3 / dt + Ndφ2 / dt = −Vout + Vin (c3)
From the above formulas (c1) to (c3), the following formula is obtained.

dφ1 / dt = Vin / N (c4)
dφ2 / dt = {− Vout / (N + N3)} + Vin / N (c5)
dφ3 / dt = Vout / (N + N3) (c6)
FIG. 3B shows a state where both the switching elements Sa and Sb are turned off. In this case, no current flows through the coil W3 due to symmetry. The coil W1 includes a positive input terminal (a terminal of the smoothing capacitor 14), a coil W1, a diode D1, a diode D3, and a positive output terminal (the output capacitor 12), as indicated by a broken line in the figure. Current flows through the terminal). The coil W2 includes a positive input terminal (a terminal of the smoothing capacitor 14), a coil W2, a diode D2, a diode D4, and a positive output terminal (an output capacitor) as indicated by a dashed line in the figure. Current flows through the path of 12 terminals).

  In this case, the following formula is established.

dφ1 / dt = dφ2 / dt = (− Vout + Vin) / N (c7)
dφ3 / dt = 0 (c8)
FIG. 3C shows a state in which the switching element Sb is turned on and the switching element Sa is turned off. In this case, when the input voltage Vin is applied to the coil W2, as indicated by the alternate long and short dash line in the figure, the current flows through the positive input terminal (the terminal of the smoothing capacitor 14), the coil W2, and the switching element Sb. Flows. Thus, the magnetic flux φ2 interlinking the coil W2 increases gradually while being proportional to the input voltage Vin and inversely proportional to the number of turns N2 of the coil W2.

  When the magnetic flux φ2 gradually increases, the magnetic flux φ3 that links the coil W3 gradually decreases. Thereby, according to the Lenz rule, an electromotive force is generated in the coil W3 so as to flow a current in a direction that prevents the decrease of the magnetic flux φ3. For this reason, the diodes D1 and D4 are turned on, and as shown by a broken line in the figure, the positive side input terminal (the terminal of the smoothing capacitor 14), the coil W1, the diode D1, the coil W3, the diode D4, and the positive side Current flows through the output terminal (terminal of the output capacitor 12). At this time, the magnetic flux generated by the current flowing through the coil W1 and the magnetic flux generated by the current flowing through the coil W3 are set to be in the same direction in a loop path that links both the coil W1 and the coil W3. The “magnetic flux generated by the current flowing through the coil W3” herein refers to a magnetic flux in the same direction as the illustrated magnetic flux φ3.

  Here, in view of the fact that the turns N1 and N2 of the coils W1 and W2 are the common turn N as described above, and using the turn N3 of the coil W3, the following equation is established.

Ndφ2 / dt = Vin (c9)
N3dφ3 / dt + Ndφ1 / dt = −Vout + Vin (c10)
From the above equations (c1), (c9), and (c10), the following equations are obtained.

dφ1 / dt = {− Vout / (N + N3)} + Vin / N (c11)
dφ2 / dt = Vin / N (c12)
dφ3 / dt = −Vout / (N + N3) (c13)
Here, from the energy conservation law, in view of the fact that the energy stored in the DC magnetic flux interlinking the coil W1 in the period T becomes equal to the energy released from the DC magnetic flux, the fluctuation amount of the magnetic flux φ1 during the period T Since is zero, the following equation holds.

DVin / N
+ D [{− Vout / (N + N3)} + Vin / N]
+ (1-2D) (-Vout + Vin) / N
= 0 (c14)
From the above, the following equation is derived as “N3 / N = n”.

Vout / Vin = 1 + [D (1 + 2n) / {(1 + n) -D (1 + 2n)}]
... (c15)
Next, when the duty ratio D is greater than 0.5, the relationship between the duty ratio D and the output voltage Vout is derived.

  When both the switching elements Sa and Sb are turned on, the path of the current flowing through the coil W1 is as shown in FIG. 3A, and the path of the current flowing through the coil W2 is shown in FIG. Therefore, the above equations (c2) and (c12) are established. Incidentally, in this case, since no voltage is applied to the coil W3, “dφ3 / dt = 0”.

  From the above, in view of the fact that the fluctuation amount of the magnetic flux φ1 becomes zero during the period T, the following equation is established.

DVin / N + (1-D) [{− Vout / (N + N3)} + Vin / N] = 0
... (c17)
Therefore, the following formula is established.

Vout / Vin = (1 + n) / (1-D) (c18)
The boost ratio (Vout / Vin) shown in the above (c15) and (c18) is larger than the boost ratio of the known boost chopper circuit shown in FIG. This is because, by using the coil W3, the number of turns of the coil used for gradually increasing the DC magnetic flux interlinking the coils W1 and W2 and at least a part of the period for gradually decreasing the DC magnetic flux. This is realized by making the number of turns of the coil used for gradually decreasing in the period. Hereinafter, this will be described by taking a DC magnetic flux (magnetic flux φ1) interlinking the coil W1 as an example.

  The period in which the magnetic flux φ1 is gradually increased is the period shown in FIG. 3A. In this period, the number of turns of the coil used for gradually increasing the magnetic flux φ1 is as shown in the above formula (c2). Is equal to the number N of turns of the coil W1. On the other hand, among the period shown in FIG. 3B and the period shown in FIG. 3C, which are periods in which the coil magnetic flux φ1 is gradually reduced, in the period shown in FIG. As can be seen, the number of turns of the coil used for gradually decreasing the magnetic flux φ1 does not match the number of turns N of the coil W1. If the number of turns is defined as a value when it is assumed that a voltage of “Vin−Vout” is applied to a single coil used for gradually decreasing the magnetic flux φ1, the value is larger than the number of turns N. It has become. This is a result of setting the direction of the magnetic flux generated when current flows through the coils W1 and W3 to be the same in a loop path that links both the coils W1 and W3.

  As described above, by increasing the virtual number of turns of the coil used to gradually reduce the DC magnetic flux in the state shown in FIG. 3C, the entire period in which the magnetic flux φ1 is gradually reduced is increased. Compared to the case shown in FIG. 3B, the average rate of decrease of the magnetic flux φ1 becomes smaller if the differential pressure between the input voltage Vin and the output voltage Vout is the same. However, since the gradually increasing amount of the magnetic flux φ1 is fixed to a value determined by the time ratio D regardless of the presence or absence of the state of FIG. 3C, the gradually increasing amount and the gradually decreasing amount of the magnetic flux φ1 in the period T are the same. Therefore, the absolute value of the differential pressure is increased as compared with the case where there is no state shown in FIG. This is the reason why the boost ratio becomes large.

  Incidentally, as shown in the above formulas (c5) and (c11), in this embodiment, a single coil to which a voltage of “−Vout + Vin” is applied to gradually decrease the magnetic fluxes φ1 and φ2 cannot be assumed. This is because the coil W3 is shared by the loop path that links both the coil W1 and the coil W3 and the loop path that links both the coil W2 and the coil W3.

  In addition, in the present embodiment, the ripple of current input from the smoothing capacitor 14 to the converter CNV can be reduced. This is due to the following reason.

  The current flowing through each of the coils W1 to W3 is I1 to I3, and Ampere's law is applied to each of the loop path that links both the coils W1 and W3 and the loop path that links both the coils W2 and W3. Then, the following formula is established.

N · I1−N3 · I3 = R1 · φ1 + R3 · φ3 (c19)
N · I2 + N3 · I3 = R2 · φ2−R3 · φ3 (c20)
Here, the magnetoresistance R1 is a magnetoresistance of a portion in which a common portion with a loop path linking both the coils W2 and W3 is removed from a path linking both the coils W1 and W3. R2 is the magnetoresistance of the portion excluding the common portion in the path that links both the coils W2 and W3. Further, the magnetic resistance R3 is a magnetic resistance of the common part.

  From the above equations (c19) and (c20), the following equation (c21) is established.

Iin = I1 + I2 = (R1 · φ1 + R2 · φ2) / N (c21)
From the above equation (c21), it can be seen that the input current Iin is a continuous amount in view of the fact that the magnetic fluxes φ1 and φ2 are continuous amounts. In particular, as in this embodiment, when the phase between the period during which the switching element Sa is turned on and the period during which the switching element Sb is turned on is shifted by π, the gradually increasing period of the magnetic flux φ1 and the gradually increasing period of the magnetic flux φ2 are They can be separated as much as possible, and the ripple of the input current Iin can be suppressed. Furthermore, in this embodiment, the magnetic resistance of the path that links both the coils W1 and W3 and the magnetic resistance of the loop path that links both the coils W2 and W3 are the same, and therefore the change in the magnetic flux φ1 and the magnetic flux φ2 Therefore, the ripple of the input current Iin can be further reduced.

  Further, according to the above equations (c6) and (c13), the absolute value of the change rate of the magnetic flux φ3 is the same in the state shown in FIG. 3A and the state shown in FIG. The sign is reversed, and according to the above equation (c8), the magnetic flux φ3 does not change in the state shown in FIG. For this reason, according to the present embodiment in which the durations of the state shown in FIG. 3A and the state shown in FIG. 3B are equal to each other, the number of turns of the coils W1 and W2 is made equal. In cooperation with this setting, the DC component of the magnetic flux φ3 can be made zero. As a result, since the foot 22 is not DC-magnetized, the foot 22 can be reduced in size.

  Further, in the present embodiment, as described above, the phase at which the switching element Sa is turned on and the phase at which the switching element Sb is turned on are shifted from each other by π, thereby suppressing loss as much as possible. That is, in view of the above formulas (c2), (c7), (c11), etc., the absolute change rate of the magnetic fluxes φ1 and φ2 in a state where both of the switching elements Sa and Sb are turned on or both are turned off. The value is larger than the absolute value of the change rate of the magnetic flux on the side corresponding to ON in a state where only one of the switching elements Sa and Sb is ON. In view of the fact that the loss in the core 20 is largely proportional to the square of the change rate of the magnetic flux, shortening both the ON period and the OFF period of the switching elements Sa and Sb as much as possible can reduce the loss. Then, since it is desirable, the setting of the phase is optimal in reducing the loss.

  Hereinafter, typical effects in the present embodiment will be listed.

  (1) The DC magnetic flux interlinking the coils W1 and W2 was gradually increased by the coils W1 and W2, and then gradually decreased by the cooperation of the coils W1 and W3, and the coils W2 and W3. Thereby, the freedom degree of adjustment of the increase rate of DC magnetic flux and the reduction | decrease speed can be improved, and the freedom degree for adjusting an output voltage by extension is improved.

  (2) When a current is passed from one of the coils W1, W3 (coils W2, W3) to the other, the pair of coils W1, W3 with respect to the magnetic flux induced by each of the coils W1, W3 (coils W2, W3). The directions in the loop path that links (coils W2, W3) are made equal to each other. Thereby, the step-up ratio can be improved.

  (3) Boosting processing was performed using two sets of coils W1, W3 and coils W2, W3. This makes it easier to reduce the ripple of the input current of converter CNV as compared with the case where only coils W1 and W3 are used. In addition, when gradually increasing the DC magnetic flux interlinking the coil W1 using only the coil W1, the coil W3 generates a voltage that increases the required withstand voltage of the flow regulating elements (switching elements Sa and Sb, diodes D1 to D4). Application can be avoided.

  (4) The direction in which the magnetic flux generated in the coil W1 is linked to the coil W3 when the input voltage Vin is applied to the coil W1, and the magnetic flux generated in the coil W2 is linked to the coil W3 when the input voltage Vin is applied to the coil W2. The direction of intersection was set to be opposite. Thereby, when the core 20 is shared by the coil W1 and the coil W2, it is easy to reduce the size of the core 20.

  (5) The low magnetic permeability member Lμ is provided in a portion other than the common portion of the loop path that links both the coils W1 and W3 and the loop path that links both the coils W2 and W3. Thereby, the core 20 can be suitably downsized while increasing the energy that can be stored in the core 20 in cooperation with the above-described polarity setting of the voltage induced in the coil W3. That is, the energy density stored in the core 20 is B · B / (2 · μ) using the magnetic flux density B and the magnetic permeability μ. For this reason, energy is concentrated on the low magnetic permeability member Lμ by making the magnetic permeability of the low magnetic permeability member Lμ sufficiently smaller than the magnetic permeability of the core 20. Here, when the low magnetic permeability member Lμ is provided in the common portion, the energy stored in the low magnetic permeability member Lμ is small because the magnetic flux φ3 is offset by the magnetic flux φ1 and the magnetic flux φ2. For this reason, in order to increase the energy stored in the core 20, it is required to increase the size of the parts other than the common part.

  (6) In the state shown in FIG. 3A, when the DC magnetic flux interlinking the coil W1 is gradually increased using only the coil W1, the current on the side that cancels the increase in the magnetic flux flows to the coil W3. Thus, the current flowing in the coil W1 during this period can be increased as compared with the case where only the coil W1 is used. That is, the following formula is established in the period in which the DC magnetic flux of the coil W1 is gradually increased.

R1 · φ1 + R3 · φ3 = N1 · I1-N3 · I3
Here, since φ1 and φ3 are determined by the voltage and the number of turns applied to the coils W1 and W3, the left side depends only on the applied voltage and the number of turns. On the other hand, when only the coil W1 is used, the following equation is established.

(R1 + R3) · φ1 = N1 · I1
Here, the value obtained by subtracting only the coil W1 from “N1 · I1” according to the present embodiment is “R3 · (φ3−φ1) + N3 · I3”. Here, in this embodiment, the low magnetic permeability member Lμ is provided in a portion other than the common portion of the loop path that links both the coils W1 and W3 and the loop path that links both the coils W2 and W3. The magnetic resistance R3 of the common portion can be reduced, so that “R3 · (φ3−φ1)” can be made smaller than “N3 · I3”. Therefore, when it is noted that the sign of the current in the above equation is based on Ampere's law when the direction of the magnetic flux φ1 is positive, the current I3> 0, so that “R3 · (φ3-φ1) + N3 · I3> 0 ”. Therefore, the input energy “Vin · I1” can be increased as compared with the case where only the coil W1 is used, and the boost ratio can be increased.
<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 4 shows a configuration of the converter CNV according to the present embodiment. In FIG. 4, the same reference numerals are assigned for convenience to the members corresponding to those shown in FIG.

As shown in the figure, in this embodiment, a core 20a that constitutes a loop path that links both the coil W1 and the coil W3, and a core 20b that constitutes a loop path that links both the coil W2 and the coil W3. Is a separate member. In particular, in this embodiment, toroidal cores are employed as the cores 20a and 20b. In this case, since the cores 20a and 20b are annular, there are no corner portions where heat generation is likely to occur, and thus the heat dissipation of the converter CNV can be improved.
<Third Embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 5 shows a configuration of the converter CNV according to the present embodiment. In FIG. 5, the same reference numerals are given for convenience to those corresponding to the members shown in FIG. 1.

  As shown in the figure, in this embodiment, a smoothing inductor (coils W4, W5) for smoothing the current output to the output capacitor 12 is provided, and a magnetic core that links the inductors and coils W1, W2 are provided. , W3 are integrally formed with a magnetic core interlinking. This can be done by adding to the core 20 legs 26 and 27 that link the coils W4 and W5, respectively.

  Here, in order to prevent the magnetic flux generated by the coils W4, W5 from interfering with the magnetic fluxes of the coils W1, W2, W3, first, the magnetic flux generated by the coil W4 in the loop path that links both the coils W4, W5. It is necessary to make the direction and size the same as the direction and size of the magnetic flux generated by the coil W5. Second, it is necessary not to provide the low magnetic permeability member Lμ in the common region of the loop path that links both the coils W4 and W5 and the loop path that links both the coils W1 and W2. The first condition is realized by making the turns of the coils W4 and W5 equal to each other and winding the coils W4 and W5. Here, the fact that the absolute values of the voltages applied to the coils W4 and W5 are equal to each other is used. The second condition is realized by providing the low permeability member Lμ on the legs 21, 23, 26 and 27.

In particular, in the present embodiment, the direction of the magnetic flux generated when current flows through the coils W4 and W5 and the direction of the magnetic flux generated when voltage is applied to the coils W1 and W2 link both the coils W1 and W2. The reverse direction is set on the intersecting loop route. Thereby, since the magnetic flux of the connection parts 24 and 25 can be reduced, the core 20 can be reduced in size.
<Fourth Embodiment>
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 6 shows a configuration of the converter CNV according to the present embodiment. In FIG. 6, the same reference numerals are given for convenience to those corresponding to the members shown in FIG. 1.

In the present embodiment, there are further provided legs 28 and 29 in which the coil W3 is linked by both the leg 21 that links the coil W1 and the leg 23 that links the coil W2, and the coil W3 is not linked. It was. Here, the legs 28 and 29 are elements constituting a loop path that links the coil W3. According to such a configuration, the coils W1 to W3 are sandwiched between the legs 28 and 29, and the legs 28 and 29 can be used as electromagnetic shields for shielding electromagnetic noise from the coils W1 to W3 and the like.
<Fifth Embodiment>
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  FIG. 7 shows a system configuration according to the present embodiment. In FIG. 7, components corresponding to those shown in FIG. 1 are given the same reference numerals for convenience.

  The converter CNV according to the present embodiment steps down the terminal voltage (input voltage Vin) of the high voltage battery 10 and outputs it as an output voltage Vout. This can be realized by connecting the switching elements S1 to S4 in parallel to the diodes D1 to D4 and using the switching elements Sa and Sb as diodes Da and Db. In the present embodiment, N-channel MOS field effect transistors are assumed as the switching elements S1 to S4. For this reason, the diodes D1 to D4 may be body diodes of transistors.

  On the other hand, the control device 30 performs step-down processing by outputting the operation signals ms1 to ms4 to the switching elements S1 to S4, respectively. FIG. 8 shows a switching operation technique for the step-down process according to the present embodiment. Specifically, FIGS. 8 (a1) and 8 (a2) show the transition of the operation signal ms1, FIGS. 8 (b1) and 8 (b2) show the transition of the operation signal ms2, and FIG. 8 (c1). 8 (c2) shows the transition of the operation signal ms3, and FIGS. 8 (d1) and 8 (d2) show the transition of the operation signal ms4. 8 (a1) to FIG. 8 (d1), the time ratio D of the on-time of the switching elements S1, S4 (S2, S3) with respect to the on / off period T of the switching elements S1 to S4 is “0.5. 8 (a2) to FIG. 8 (d2) show cases where the duty ratio D is larger than “0.5”.

  Here, during the period when the switching elements S1 and S4 are turned on, the positive input terminal (terminal of the smoothing capacitor 14) is connected to the positive output terminal (terminal of the output capacitor 12) via the coils W3 and W1. Current flows. This period is a period in which energy is stored by gradually increasing the DC magnetic flux interlinking the coil W1.

  On the other hand, during the period when the switching elements S2 and S3 are turned on, or during the period when all of the switching elements S1 to S4 are turned off or on, the positive electrode is connected from the negative input (output) terminal via the diode Da and the coil W1. Current flows through the output terminal on the side (terminal of the output capacitor 12). This period is a period in which energy is released by the gradual decrease of the DC magnetic flux interlinking the coil W1.

  Here, the output voltage Vout is determined in view of the fact that the amount of increase and decrease of the DC magnetic flux in the period T are equal according to the energy conservation law. In particular, in the present embodiment, when energy is stored, the coil W3 is used in addition to the coil W1. For this reason, the increasing speed of the magnetic flux φ1 is smaller than when only the coil W1 is used. Therefore, the output voltage Vout is smaller than when the magnetic flux φ1 is increased or decreased using only the coil W1.

  Actually, in this embodiment, the following equation (c22) is established when D = 0.5 or less, and the following equation (c23) is established when D> 0.5.

Vout / Vin = D / (1 + n) (c22)
Vout / Vin = D − [(1-D) · n / (1 + n)] (c23)
These are smaller than the step-down ratio D of the known step-down chopper circuit. Furthermore, in the present embodiment, the following equation is established during the period in which the DC magnetic flux (magnetic flux φ1) is gradually increased, and the fact that the input energy can be reduced also contributes to further lowering the step-down ratio.

R1 · φ1 + R3 · φ3 = N1 · I1 + N3 · I3
<Sixth Embodiment>
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 9 shows a system configuration according to the present embodiment. In FIG. 9, components corresponding to those shown in FIG. 1 are given the same reference numerals for convenience.

  The converter CNV according to the present embodiment has both a function of boosting the input voltage Vin and a function of stepping down the output voltage Vout. This can be realized by combining the configuration of the first embodiment (FIG. 1) and the configuration of the fifth embodiment (FIG. 7). That is, it is realizable by providing switching element Sa, Sb, S1-S4, and diode Da, Db, D1-D4.

  On the other hand, the control device 30 performs step-up processing and step-down processing by outputting operation signals msa, msb, ms1-ms4 to the switching elements Sa, Sb, S1-S4, respectively. Here, when performing the boosting process, the switching elements Sa and Sb may be operated in the same manner as in the first embodiment, and the switching elements S1 to S4 are turned off and diodes connected in reverse parallel thereto. D1 to D4 are used. On the other hand, when the step-down process is performed, the switching elements S1 to S4 are operated, and the switching elements Sa and Sb are turned off, and the diodes Da and Db connected in reverse parallel thereto are used.

  FIG. 10 shows a switching operation in the step-down process. FIG. 10 (a) shows the transition of the operation signal ms1, FIG. 10 (b) shows the transition of the operation signal ms2, FIG. 10 (c) shows the transition of the operation signal ms3, and FIG. Indicates the transition of the operation signal ms4. Since the switching operation shown in FIG. 10 can be used when “D <0.5”, it is assumed that the switching operation is limited to “D <0.5” in this embodiment. Also in this embodiment, in order to suppress the ripple current as much as possible, the phase between the period during which the switching elements S1, S4 are turned on and the period during which the switching elements S2, S3 are turned on is set to be shifted by π. This can be realized by setting the period during which the switching elements S1 to S4 are turned on to “0.5 × T”.

As illustrated, in the present embodiment, after energy is stored by turning on the switching element S1 and the switching element S4, the switching element S1 is turned off and the switching element S3 is turned on. Then, after switching element S4 is turned off and switching element S2 and switching element S3 are turned on to store energy, switching element S3 is turned off and switching element S1 is turned on. Note that the change in magnetic flux is the same as the period when the switching elements S1 to S4 are turned off during the period when the switching elements S3 and S4 are turned on and the period when the switching elements S1 and S2 are turned on.
<Seventh Embodiment>
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 11 shows a system configuration according to the present embodiment. In FIG. 11, the same reference numerals are given for the sake of convenience to those corresponding to the members shown in FIG. 1.

  In the converter CNV according to this embodiment, the polarity of the output voltage is inverted with respect to the input voltage Vin. This is realized by connecting one end of the switching elements Sa and Sb to the negative electrode side of the high-voltage battery 10 in the configuration of the sixth embodiment (FIG. 9).

On the other hand, the control device 30 performs step-up processing and step-down processing by outputting operation signals msa, msb, ms1-ms4 to the switching elements Sa, Sb, S1-S4, respectively. Here, when performing a boosting process in which the absolute value of the input voltage Vin is increased to obtain the output voltage Vout, the switching elements Sa and Sb may be operated in the manner of the first embodiment, and the switching elements S1 to S4. Is used, and diodes D1 to D4 which are turned off and connected in reverse parallel are used. On the other hand, when stepping down the input voltage Vin by reducing the absolute value of the output voltage Vout, the switching elements S1 to S4 are operated, the switching elements Sa and Sb are turned off, and the diodes connected in reverse parallel thereto. Da and Db are used. The operation of the switching elements S1 to S4 at this time may be the same as that shown in FIG.
<Other embodiments>
Each of the above embodiments may be modified as follows.

“Direction of flux linkage of coil W3”
For example, in the first embodiment, when the input voltage Vin is applied to the coil W1, the magnetic flux generated in the coil W1 is linked to the coil W3, and when the input voltage Vin is applied to the coil W2, the coil The direction in which the magnetic flux generated in W2 links the coil W3 may be the same. Here, for example, when such setting is realized by changing the winding method of the coil W1, the cathode side of the diode D1 may be connected to the cathode side of the diode D2.

"First to fourth rectifying means, first coil rectifying means, and second coil rectifying means"
It is not limited to the diodes D1 to D4 and the diodes Da and Db. For example, a thyristor may be used.

"About the 1st-4th opening and closing means"
It is not limited to an N channel MOS field effect transistor, but may be any field effect transistor such as a P channel MOS field effect transistor. Moreover, not only a field effect transistor but IGBT etc. may be sufficient, for example.

"About coupling means"
The fact that the coupling means is not limited to one that makes the end of the coil W3 connected to the coil W1 different from the end of the coil W3 connected to the coil W2, "about the direction of the interlinkage magnetic flux of the coil W3" It is as described in the column.

"Powering and regenerative control"
For example, in the configuration of the previous sixth embodiment (FIG. 9), the switching element Sa and the switching elements S1 and S4 are alternately turned on (complementary driving), and the switching element Sb and the switching elements S2 and S3 are turned on. Complementary driving may be performed. Specifically, when operating the switching elements S1 to S4 as shown in FIGS. 8 (a1) to 8 (d1), the switching elements Sa1 and S4 are set to the off periods of the switching elements Sa, and the switching elements Sa1 and S4 are operated. The off period of S2 and S3 may be the on period of the switching element Sb. As a result, power running control and regenerative control are performed according to the magnitude relationship between the input voltage Vin and the output voltage Vout. This is possible because in the above formulas (c15) and (c18), when the time ratio D is replaced with “1-D”, the above formulas (c23) and (c22) are obtained. is there. Incidentally, when operating the switching elements S1 to S4 as shown in FIG. 10A to FIG. 10D, the off period of the switching element S1 is set as the on period of the switching element Sa, and the off period of the switching element S2 is set as the off period. It is good also as an ON period of switching element Sb.

  In addition, the method of leaving power running and regenerative control in this way is also possible in the configuration of the seventh embodiment (FIG. 11).

“Low permeability member Lμ”
The arrangement of the low magnetic permeability member Lμ is not limited to that exemplified in the first embodiment. However, in the case where the magnetic core is shared between the coil W1 and the coil W2 and the magnetic flux induced in the coil W3 is set to be alternating current, in order to store large energy, the low magnetic permeability member Lμ is set to the region LA, FIG. It is desirable to provide each LB. However, in the configuration of the third embodiment (FIG. 5), it is desirable that the low magnetic permeability member Lμ is not provided in the connection portions 24 and 25. Thereby, it is possible to avoid the behavior of the input current and the output current from interfering with each other.

  In the fourth to seventh embodiments, the configuration in which the core 20 does not include the low magnetic permeability member Lμ is illustrated, but may be provided.

  It is also possible to provide the low magnetic permeability member Lμ at the portion where the coil W3 is linked. Further, the magnetic flux generated in the coil W1 when the input voltage Vin is applied to the coil W1 is linked to the coil W3, and the magnetic flux generated in the coil W2 when the input voltage Vin is applied to the coil W2 is applied to the coil W3. When the direction of linkage is the same, large energy can be stored in the core 20 even if the low magnetic permeability member Lμ is provided only in the portion linked to the coil W3.

  Instead of providing the low magnetic permeability member Lμ, the portion where it is formed may be a space (gap).

"Magnetic resistance of a pair of loop paths"
Although it is desirable that the magnetic resistances of the loop path that links the coils W1 and W3 and the loop path that links the coils W2 and W3 are equal to each other, the setting that the magnetic resistances are equal is not essential.

“Number of coils”
It is not restricted to what consists of coils W1, W2, W3. For example, as shown in FIG. 13, it may consist of coils Wa, Wb, Wc, Wd, We, Wf. Here, each of the coils Wa, Wb, Wd corresponds to the coils W1, W2, W3 of the first embodiment, and each of the coils Wb, Wc, Wf is a coil W1, of the first embodiment. The coils Wc, Wa, and We correspond to the coils W1, W2, and W3 of the first embodiment, respectively.

“Direction of magnetic flux induced by a pair of coils connected in series”
The magnetic flux induced when a current flows through a pair of coils connected in series (coils W1 and W3, etc.) is not limited to the same direction in the loop path linking the pair of coils, but is reversed. It may be the case.

“Purpose of using a pair of coils connected in series”
It is not limited to those used for increasing the step-up ratio or lowering the step-down ratio. If the rate of change of the output voltage with respect to the time ratio D is reduced by setting the step-up ratio to be lowered or the step-down ratio to be increased, fine adjustment of the output voltage is facilitated. .

“Input voltage”
For example, in the first embodiment (FIG. 1), the terminal voltage of each battery is applied so that the input voltage applied to the coil W1 and the input voltage applied to the coil W2 are different from each other. May be.

  Moreover, the terminal voltage of the DC voltage source is not limited to the direct input voltage, and an inductor as a filter may be provided between the DC voltage source and the input terminal of the converter CNV.

"Symmetry of circuit and operation"
The number of turns of the coils W1, W2 is not limited to the same. Moreover, the magnetic resistance of the loop path | route which links both the coil W1 and the coil W3 and the loop path | route which links both the coil W2 and the coil W3 is not restricted to be the same. In particular, as described in the “input voltage” column, when the applied voltages of the coils W1 and W2 are different, by making the number of turns and the magnetic resistance the same, the symmetry of the electrical state can be increased. Since it cannot be maintained, the symmetry of the electrical state may be restored as much as possible by shifting these or changing the time ratio D.

"others"
In the fifth embodiment (FIGS. 7 and 8), if “D <0.5”, the switching operation of the sixth embodiment (FIG. 10) may be performed.

  In the sixth embodiment (FIGS. 9 and 10) and the seventh embodiment (FIG. 11), the switching operation of the fifth embodiment (FIGS. 7 and 8) may be performed.

  The phase of the voltage application period to the pair of coils W1 and W2 is not limited to that shifted by π.

  In the third embodiment, the direction of the magnetic fluxes φ4 and φ5 may be reversed. In this case, even if the low magnetic permeability member Lμ is provided in the common part of the loop path that links the coil W1 and the coil W2 and the loop path that links the coil W4 and the coil W5, it is possible to store large energy. Become. However, in order to avoid interference between the behavior of the input current and the behavior of the output current, it is desirable to provide the low magnetic permeability member Lμ in a portion other than the common portion even in this case.

  In the third embodiment, the coils W4 and W5 are not limited to the smoothing inductor, but may be coils used in another circuit.

  The input voltage is not limited to the terminal voltage of the high voltage battery 10. For example, it may be the terminal voltage of the fuel cell.

  -As a power converter, it is not restricted to what is mounted in a vehicle.

  Sa ... switching element (one embodiment of first coil opening / closing means), Sb ... switching element (one embodiment of second coil opening / closing means), W1 ... coil (one embodiment of first coil), W2 ... coil (One Embodiment of Second Coil), W3... Coil (One Embodiment of Third Coil).

Claims (13)

In the voltage converter that converts the magnitude of the input voltage and outputs it as an output voltage,
A pair of input terminals to which the input voltage is applied and a pair of output terminals to which the output voltage is applied; and the input voltage, the output voltage, and the input voltage and the output voltage a pair of first voltage application terminal Chi caries differential pressure, the first voltage is any one of a voltage applied between,
And a pair of terminals of a pair of the entering force pin and the pair of the output pin, the input voltage, the output voltage, and Chi differential pressure sac between the input voltage and the output voltage, A pair of second voltage application terminals to which a second voltage which is any one voltage other than the first voltage is applied ;
A first coil and a second coil magnetically coupled to each other and connected in series with each other ;
A first loop path that is a loop path that links the first coil and that does not link the second coil; and a loop path that links the second coil and does not link the first coil. A magnetic core constituting the second loop path;
Wrapped around the magnetic core so as to be linked to both the first loop path and the second loop path, and the opposite side of the both ends of the first coil to the side to which the second coil is connected A third coil connecting the opposite side of the second coil to the side to which the first coil is connected;
Upon application of a both ends to said first through the voltage applying terminal of the first voltage of the first coil, the first coil and through said series connection point between the first coil the second coil first avoids current flows between 2 coils, wherein upon the second via the first voltage application terminal to both ends of the coil for applying the first voltage, said through a series connection point first coil and Separating means for avoiding current from flowing between the second coils ;
The second voltage application terminal is interposed between a side of the first coil where the second coil is connected and a side of the third coil where the second coil is connected. Applying a second voltage, the second voltage between a side of the second coil connected to the first coil and a side of the third coil connected to the first coil. Coupling means for applying the second voltage via an application terminal ;
The first period for applying the first voltage to the coil, and the side where the second coil is connected among both ends of the first said the side where the second coil is connected among the both ends of the coil the third coil In one of the pair of periods in which the second voltage is applied between the two, the DC magnetic flux interlinking the first coil is increased in one period, and the first coil is interlinked in the other period. The voltage conversion device is configured to reduce the direct current magnetic flux,
The period during which the first voltage is applied to the second coil, and the side of the second coil where the first coil is connected and the side of the third coil where the first coil is connected Between the pair of periods in which the second voltage is applied between them, the DC magnetic flux interlinking the second coil is increased in one of the periods, and the second coil is interlinked in the other period. The voltage conversion device is configured to reduce the direct current magnetic flux,
The second voltage is applied between a side where the second coil is connected among both ends of the first coil and a side where the second coil is connected among both ends of the third coil, When current flows through each of the first coil and the third coil, the current is induced by each of the first coil and the third coil in a loop path that links both the first coil and the third coil. Each of the first coil and the third coil is wound around the magnetic core such that the directions of magnetic fluxes are equal to each other,
The second voltage is applied between a side of the second coil connected to the first coil and a side of the third coil connected to the first coil. When a current flows through each of the second coil and the third coil, each of the second coil and the third coil is induced in a loop path that links both the second coil and the third coil. Each of the second coil and the third coil is wound around the magnetic core so that the directions of the magnetic fluxes are equal to each other,
The direction in which the magnetic flux generated in the first coil interlinks the third coil when the first voltage is applied to the first coil, and the second when the first voltage is applied to the second coil. Each of the first coil, the second coil, and the third coil is wound around the magnetic core so that the magnetic flux generated in the coil is opposite to the direction in which the third coil is linked.
A direction in which the magnetic flux generated in the first coil links the second coil when the first voltage is applied to the first coil in a loop path that links both the first coil and the second coil. And the first coil and the second coil such that when the first voltage is applied to the second coil, the magnetic flux generated in the second coil is equal to the direction in which the first coil is linked to the first coil. Each of which is wound around the magnetic core . A state in which the second voltage is applied to the second coil and the third coil by the coupling means, and a state in which the first voltage is applied to the first coil; and the first coil and the first coil by the coupling means 3 voltage conversion device according to claim 1 Symbol mounting and having a state where the second voltage is applied and to the second coil in the coil first voltage is applied. The pair of first voltage application terminals is a pair of the input terminals to which the input voltage is applied,
The pair of second voltage application terminals is a pair of the output terminals to which the output voltage is applied,
The first voltage is the input voltage;
The second voltage is a differential pressure between the input voltage and the output voltage,
The separating means and the coupling means are:
First rectifying means for connecting the first coil and the third coil and allowing a current flow from the first coil to the third coil and preventing a reverse current flow;
A second rectifying means for connecting the second coil and the third coil and allowing a current flow from the second coil to the third coil and preventing a reverse current flow;
Third rectifying means that allows current flow from the output side of the first rectifying means to the output terminal and prevents reverse current flow;
A fourth rectifying means for allowing a current flow from the output side of the second rectifying means to the output terminal and blocking a reverse current flow;
First coil opening and closing means for electrically opening and closing between the first coil and the input terminal;
Second coil opening and closing means for electrically opening and closing between the second coil and the input terminal;
Equipped with a,
In a period in which the first voltage is applied to the first coil, a direct-current magnetic flux that links the first coil is increased, and a side of the first coil, to which the second coil is connected, and the third coil The voltage conversion device is configured to reduce a direct-current magnetic flux interlinking the first coil during a period in which the second voltage is applied between the opposite ends of the first coil and the side to which the second coil is connected. ,
In a period in which the first voltage is applied to the second coil, a direct-current magnetic flux that links the second coil is increased, and a side of the second coil, to which the first coil is connected, and the third coil the voltage conversion device has been configured to reduce the DC magnetic flux interlinked with the second coil in the period for applying the second voltage to between the side of the first coil is connected among the ends of the The voltage converter according to claim 2 . The pair of first voltage application terminals is a pair of the output terminals to which the output voltage is applied,
The pair of second voltage application terminals is a pair of the input terminals to which the input voltage is applied,
The first voltage is a differential pressure between the input voltage and the output voltage,
The second voltage is the output voltage;
The separating means and the coupling means are:
First opening and closing means for electrically opening and closing between the first coil and the third coil;
Second opening and closing means for electrically opening and closing between the second coil and the third coil;
Third opening and closing means for electrically opening and closing between one end of the third coil and the input terminal;
A fourth switching means for electrically opening and closing between the other end portion and the input terminal of the third coil,
Rectifying means for a first coil that allows a current to flow from the low potential side to the high potential side of the output terminal via the first coil and prevents the current from flowing in the reverse direction;
Rectifying means for second coil that allows current to flow from the low potential side to the high potential side of the output terminal via the second coil and prevents the current from flowing in the reverse direction;
Equipped with a,
In a period in which the first voltage is applied to the first coil, a direct-current magnetic flux that links the first coil is increased, and a side of the first coil, to which the second coil is connected, and the third coil The voltage conversion device is configured to reduce a direct-current magnetic flux interlinking the first coil during a period in which the second voltage is applied between the opposite ends of the first coil and the side to which the second coil is connected. ,
In a period in which the first voltage is applied to the second coil, a direct-current magnetic flux that links the second coil is increased, and a side of the second coil, to which the first coil is connected, and the third coil the voltage conversion device has been configured to reduce the DC magnetic flux interlinked with the second coil in the period for applying the second voltage to between the side of the first coil is connected among the ends of the The voltage converter according to claim 2 . The separating means and the coupling means are:
First opening and closing means for electrically opening and closing between the first coil and the third coil;
Second opening and closing means for electrically opening and closing between the second coil and the third coil;
Third opening / closing means for electrically opening / closing between one end of the third coil and the second voltage application terminal;
A fourth switching means for electrically opening and closing between the other end and said second voltage application terminal of the third coil,
First coil opening and closing means for electrically opening and closing between the first coil and the first voltage application terminal;
Second coil opening and closing means for electrically opening and closing between the second coil and the first voltage application terminal;
The voltage converter according to claim 2, further comprising: Each of the loop path that links both the first coil and the third coil and the loop path that links both the second coil and the third coil have magnetic permeability as compared with the other portions. The voltage converter of any one of Claims 1-5 provided with a low part. Wherein said magnetic core constituting a loop path that first interlinked coils and chains the third coil, and the magnetic core constituting the loop path interlinked said second coil and said third coil are formed integrally,
The low permeability portion is a portion other than a common portion of a loop path that links both the first coil and the third coil and a loop path that links both the second coil and the third coil. The voltage converter according to claim 6 , wherein the voltage converter is configured as follows. The number of turns of the first coil and the second coil is set to be equal to each other;
The magnetic resistance of the loop path that links both the first coil and the third coil and the loop path that links both the second coil and the third coil are the same. The voltage converter according to any one of claims 1 to 7 . The application period of the first voltage by the first voltage application terminal to the first coil and the application period of the first voltage by the first voltage application terminal to the second coil are the same, and The application period of the second voltage by the second voltage application terminal to the first coil and the application period of the second voltage by the second voltage application terminal to the second coil are the same. The voltage converter according to claim 8 . Only the application period of the first voltage by the first voltage application terminal to the first coil, the phases of the application period of the first voltage by the first voltage application terminal to the second coil π The voltage converter according to claim 9 , wherein the voltage converter is shifted. It said magnetic core constituting the loop path interlinked both the first coil and the third coil, the core and is integrally constituting the loop path interlinked both the second coil and said third coil The voltage conversion device according to claim 1 , wherein the voltage conversion device is formed as follows. The magnetic core further includes a loop path that does not link the first coil, the second coil, and the third coil and that links a pair of coils;
12. The voltage conversion device according to claim 11 , wherein the pair of coils induce magnetic fluxes having the same direction and size on the loop path that links them. 13. The voltage converter according to claim 12 , wherein the magnetic core is a loop path that does not link coils, and constitutes a loop path that sandwiches the first coil, the second coil, and the third coil. .

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