JP2000308271A - Energy transfer device, charging device and power supply device - Google Patents

Abstract

(57) Abstract: Provided is an energy transfer device that has high reliability, can transfer energy reliably and easily, and can be configured inexpensively and in a small size. SOLUTION: A plurality of series circuits each having at least windings 3a to 3d and switch means Sa to Sd connected in series can be provided, and each of the plurality of series circuits can be connected in parallel to each of a plurality of energy storage means Ca to Cd. The plurality of windings 3a to 3d are respectively magnetically coupled to each other, and the plurality of switch means Sa to Sd are respectively subjected to switching control in synchronization with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy transfer device connected to a plurality of energy storage means for transferring energy between the energy storage means, and a charging device. The present invention relates to an energy transfer device suitable for averaging the voltage between both ends, and a charging device and a power supply device using the energy transfer device.

[0002]

2. Description of the Related Art As this type of energy transfer device, for example, a transfer device 61 described in Japanese Patent Application Laid-Open No. 7-322516 has been conventionally known. This transfer device 61
Represents a plurality of capacitors C1 to C4 as shown in FIG.
The stored energy of the capacitors C1 to C4 can be averaged by transferring any one of the stored energy to another capacitor. In particular,
The transfer device 61 includes a series circuit of a choke coil L1 and a switch SW1 connected in parallel to the capacitor C1, a switch SW21 connected to the capacitor C2 via the choke coil L1, and a choke coil L2 connected in parallel to the capacitor C2. A series circuit of the switch SW22 and a choke coil L connected in parallel to the capacitor C3.
3 and a switch S31 connected to a capacitor C3 via a choke coil L2.
W32 and a capacitor C4 via a choke coil L3.
And a switch SW4 connected to the switch SW4.

In the transfer device 61, for example, when transferring the stored energy of the capacitor C4 to the capacitor C1, the switch SW4 is first turned on. At this time, the current I61 flows to excite the choke coil L3 as shown in FIG. Next, by simultaneously controlling the switch SW4 and the switch SW31 to the off state and the on state, respectively, a current I62 based on the excitation energy of the choke coil L3 flows, and the capacitor C3 is charged. Next, after the switch SW31 is turned off, the switch SW32 is turned on. Thus, the current I63 flows to excite the choke coil L2. Then, switch S
By simultaneously controlling the W32 and the switch SW22 to the OFF state and the ON state, respectively, a current I64 based on the excitation energy of the choke coil L2 flows, and the capacitor C2 is charged. Next, after the switch SW22 is turned off, the switch SW21 is turned on. Thus, the current I65 flows to excite the choke coil L1. Finally, switch S
By simultaneously controlling the W21 and the switch SW1 to the off state and the on state, respectively, the current I66 based on the excitation energy of the choke coil L1 flows, and the capacitor C1 is charged. As a result, the energy stored in the capacitor C4 is transferred to the capacitor C1.

[0004]

However, the conventional transfer device 61 has the following problems. That is, in the transfer device 61, for example, when transferring energy from the capacitor C4 to the capacitor C3, it is necessary to simultaneously control the switch SW4 and the switch SW31 to the off state and the on state. In this case, if the switch SW31 is controlled to the on state prior to the off state of the switch SW4, the capacitors C3 and C4 become the switches SW4 and SW4.
By short-circuiting through both capacitors C
3, C4 stored energy is lost. On the other hand, if the switch SW4 is turned off before the switch SW31 is turned on, an extremely high voltage is generated across the switch SW4, and the switch SW4 is damaged. As described above, the conventional transfer device 61 includes the switch S
If the timing of the on / off control of the switches 1 to 4 is slightly shifted, there is a problem that a short circuit of the circuit or damage of the circuit components is caused and energy cannot be transferred.

[0005] The capacitor C4 is connected to the capacitor C1.
Switches SW4 to SW1 when transferring energy to
Must be turned on / off many times with precise timing. For this reason, the transfer device 61 also has a problem that the control of the switch is complicated.

Further, in the transfer device 61, it is necessary to use six switches SW1 to SW4 for transferring energy between the four capacitors C1 to C4. In this case, considering the energy transfer between a number of capacitors, the number of switches is about twice that of the capacitors. For this reason, in the conventional transfer device 61,
There is also a problem that the number of switches is large, and it is expensive and large.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has an energy transfer device which has high reliability, can transfer energy reliably and easily, and can be constructed inexpensively and compactly. A main object is to provide a charging device and a power supply device.

[0008]

In order to achieve the above object, an energy transfer device according to claim 1 has a plurality of series circuits each having at least a winding and a switch means connected in series, and each of the plurality of series circuits is provided. Is configured to be connectable in parallel to each of the plurality of energy storage means,
The plurality of windings are magnetically coupled to each other, and the plurality of switch means are switching-controlled in synchronization with each other.

According to a second aspect of the present invention, there is provided the energy transfer apparatus according to the first aspect, further comprising a transformer having a plurality of windings, wherein the transformer is stored when the switch means is turned off. It is characterized by further comprising an energy discharging winding for discharging energy to the energy storage means.

According to a third aspect of the present invention, in the energy transfer device according to the second aspect, an energy discharging winding is connected to each winding in series, and each energy discharging winding is connected to a corresponding winding. The stored energy of the transformer is discharged to the energy storage means connected to the line.

According to a fourth aspect of the present invention, in the energy transfer apparatus of the second aspect, first to N-th series circuits (N is an integer) each comprising a winding and a switch are connected in series. And an energy emitting winding as an (N + 1) th winding is further connected in series to the series connection circuit, and an Mth winding (M is 2 or more (N + 1))
(M-1) and (M-1)
Characterized in that the energy stored in the transformer can be released to the energy storage means connected to the windings.

According to a fifth aspect of the present invention, in the energy transfer device according to any one of the second to fourth aspects, the transformer is a leakage transformer. In this case, the leakage transformer can be easily formed by forming a gap in the iron core or keeping the magnetic coupling of each winding at an appropriate level.

According to a sixth aspect of the present invention, in the energy transfer device according to any one of the first to fifth aspects, the energy storage means is a secondary battery or a capacitor. In this case, the secondary battery includes a lithium ion battery or a lithium polymer battery, and the capacitor includes an electric double layer capacitor.

According to a seventh aspect of the present invention, in the energy transfer device according to any one of the first to sixth aspects, the windings are formed with the same number of turns.

According to an eighth aspect of the present invention, in the energy transfer device according to any one of the first to seventh aspects, the switch means comprises a field effect transistor or a bipolar transistor.

A charging device according to a ninth aspect includes the energy transfer device according to any one of the first to eighth aspects, and is configured such that a series circuit can be connected in parallel to both ends of each of the plurality of objects to be charged. It is characterized by being.

According to a tenth aspect of the present invention, there is provided a power supply device including the energy transfer device according to any one of the first to eighth aspects, wherein the plurality of energy storage means are each constituted by one of a capacitor and a battery. It is characterized in that the stored energy of one energy storage means is distributed to another energy storage means.

The power supply device according to claim 11 is the power supply device according to claim 10.
In the power supply device described above, the voltage between any one of the plurality of energy storage units is stably controlled to a predetermined voltage.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the operating principle of the energy transfer device according to the present invention will be described with reference to FIG.

As shown in FIG. 1, the transfer device 1 includes, for example, four capacitors Ca as energy storage means.
To Cd (hereinafter referred to as “capacitor C”
) Are configured to transfer energy between each other. Specifically, the transfer device 1 includes the windings 3a to 3d
(Hereinafter referred to as “winding 3” when not distinguished). The transformer 2 functions as an ideal transformer having a resistance component of each winding 3 of 0Ω, no leakage inductance, and no excitation current. Each of the windings 3a to 3d is magnetically coupled to each other by an iron core, and has a number of turns Na, Nb, Nc, Nd.
And each is wound. Further, the transfer device 1
The winding end side ends of the windings 3a to 3d and the capacitors Ca to
Switches Sa to Sd (hereinafter, referred to as “switch S” when not distinguished) are respectively connected between the negative terminals of Cd. In this case, each switch S
a to Sd are constituted by, for example, FETs or bipolar transistors, and are turned on / off in synchronization with each other by a switching control circuit (not shown).

In this transfer device 1, the winding start side end of each winding 3 and the fixed contact of the corresponding switch S are connected to both ends of the capacitors Ca to Cd, respectively.
A switching control circuit controls switching of each of the switches Sa to Sd. At this time, the following equation is established between the voltages VCa-VCd between the terminals of the capacitors Ca-Cd and the number of turns Na-Nd of the winding 3. VCa: VCb: VCc: VCd = Na: Nb: Nc: Nd ... Formula

Therefore, when the switches Sa to Sd are switched, energy is transferred between the capacitors Ca to Cd. Specifically, for example, a case where a voltage higher than the voltage defined by the above equation is applied between the terminals of the capacitor Ca will be described as an example. When each of the switches Sa to Sd is turned on, only the voltage VCa between the terminals of the capacitor Ca is higher than the voltage according to the above equation. A current flows through a current path including the negative terminal of the capacitor Ca. In this case, a voltage Va having a value equal to the voltage VCa between the terminals of the capacitor Ca is generated in the winding 3a, and a voltage Vb having a value corresponding to the ratio of the winding number Na of the winding 3a to the other windings 3b to 3d. To Vd. Specifically, the value (voltage Va) is applied to the winding 3b.
× Nb / Na), and a voltage Vc of a value (voltage Va × Nc / Na) is generated in the winding 3c.
At d, a voltage Vd having a value (voltage Va × Nd / Na) is generated.

In this case, the voltages Vb to Vd are higher than the corresponding inter-terminal voltages VCb to VCd.
Therefore, the current based on each of the voltages Vb to Vd is
Each of the capacitors Cb to Cd is charged while continuing to flow through the current path including the capacitor C and the switch S. Next, the voltages Vb-Vd and the voltages VCb-
The charging is sequentially stopped from the capacitor C which has reached a voltage equal to VCd, and finally the above expression is satisfied. As a result, the energy is dispersedly transferred from the capacitor Ca to the other capacitors Cb to Cd.

As described above, according to the transfer device 1, since the number of windings 3 and the number of switches S can be equal to the number of energy storage means, the number of circuit components can be reduced. Lower prices can be achieved. In addition, since it is only necessary to perform switching control synchronously with the switches Sa to Sd, the control becomes easy, and a short circuit accident does not occur.
To Cd can be reliably transferred with high reliability.

Next, an actual circuit configuration using a realistic transformer will be described with reference to FIG. Hereinafter, the same components as those of the transfer device 1 will be denoted by the same reference numerals, and redundant description will be omitted, and redundant description of the same operation will be omitted.

As shown in FIG. 1, the transfer device 11 includes a reset winding (corresponding to an energy discharging winding in the present invention) 4 connected in series to each of the windings 3a to 3d.
a to 4d (hereinafter, referred to as "reset winding 4" when not distinguished) and reset current emitting diodes 5a to 5d (hereinafter, referred to as "diode 5" when not distinguished). ing. Each of the windings 3a to 3d is connected to a predetermined capacitor C
The voltages VCa to VCd between the terminals a to Cd are wound with the number of turns Na to Nd satisfying the above expression. Also,
Each of the reset windings 4a to 4d is wound with the number of turns NA to ND satisfying the following equation. NA / Na = NB / Nb = NC / Nc = ND / Nd Expression In this case, the ratio (NA / Na) is determined so that the transformer 2a is magnetically reset during the OFF period of the switch S.

In the transfer device 11, the switches Sa to S
In the on-state control of d, similarly to the transfer device 1, a current flows from the positive terminal to the negative terminal of the capacitor C having a voltage higher than the voltage defined by the above equation, so that each capacitor Ca The energy is transferred such that the voltages VCa to VCd between the terminals 〜CdｄCd satisfy the above formula. On the other hand, since the exciting current flows in the actual transformer 2a, the transformer 2a is magnetized when the switch S is turned on. Next, when the switches Sa to Sd are turned off, as shown in FIG.
3d and the reset windings 4a to 4d
d and VA to VD occur. In this case, since each of the windings 3a to 3d is magnetically coupled by a common iron core, a voltage corresponding to the turn ratio is generated in each of the windings based on the excitation energy of the transformer 2a.
At this time, since the switch S blocks the passage of the current based on the induced voltage of the winding 3, the currents Ia to Id based on the voltages VA to VD induced in the reset windings 4 are applied to the respective reset windings. 4, emitted through the capacitor C and the diode 5, respectively. At this time, the energy is released from the reset winding 4 to the capacitor C in the descending order of the voltage difference between the terminal voltages VCa to VCd with respect to the induced voltage of the reset winding 4.

As a result, even when the switch S is turned off, the capacitor C having a voltage higher than the voltage satisfying the above equation can be used.
Is transferred to another capacitor C, the voltages VCa to VCd between the terminals satisfy the above expression. If the turns ratio of the windings 3 is the same, the terminal voltages VCa to VCd of the capacitors Ca to Cd can be easily averaged to the same voltage. When the ratio (NA / Na) is set to a value of 1, the switch S is set to 50%
By switching at the duty, theoretically, all the excitation energy of the transformer 2a is released within the off period of the switch S. As a result, the transformer 2a
Is reliably prevented from being magnetically saturated.

The leakage transformer is connected to the transformer 2a.
When the switch S is turned on, each winding 3
When the current flows through the leakage inductance, the current flows through the leakage inductance, so that the peak value of the current can be appropriately limited.

Next, an example in which the transfer device 11 is applied to a charging / discharging device 21 will be described with reference to FIG.

The charging / discharging device 21 may be an N number of capacitors (N is an integer of 2 or more) or a secondary battery (a composite product in which a capacitor and a secondary battery are mixed) connected in series as energy storage means. Good) and the energy stored in the energy storage means is supplied to the load L. Hereinafter, an example will be described in which a series connection circuit of four capacitors Ca to Cd of the same capacity is used as the energy storage means to charge or discharge while maintaining the voltage between the terminals of the capacitors Ca to Cd at the same voltage.

The charging / discharging device 21 includes electric double layer type capacitors Ca to Cd, a transformer 2b, switches Sa to Sd,
S11, the diode 6 and the charger 22 are provided. In this case, the transformer 2b includes four windings 3a to 3d wound with the same number of turns Na to Nd,
And a reset winding 3e wound with, for example, four times the winding number Ne of the winding 3a. Further, the switches Sa to Sd are controlled in conjunction with the switching control of the switch S11, and when the charger 22 charges the capacitor C,
Alternatively, switching control is performed in synchronization with each other only when discharging from the capacitor C to the load L, and is controlled to be in the off state when charging or discharging is not performed. Further, the switch S1
Reference numeral 1 indicates that the movable contact is switched to a charging terminal during charging, switched to a discharging terminal during discharging, and switched to a stop terminal during non-charging and non-discharging. The charger 22 is configured to output a voltage sufficient to charge the four capacitors Ca to Cd.

In the charging device 21, during charging,
When each switch S is turned on, the output current of the charger 22 flows through the switch S11 to charge each of the capacitors Ca to Cd. At the same time, a current based on the stored energy of the capacitor C having the highest inter-terminal voltage flows through the current path including the positive terminal of the capacitor C, the winding 3, the switch S, and the negative terminal of the capacitor C. Thereby, the voltage between the terminals of the other capacitor C is averaged to the same voltage, and the transformer 2b is magnetized. Next, when each switch S is controlled to be turned off, voltages Va to Ve are induced in each of the windings 3a to 3e based on the energy stored in the transformer 2b, as shown in FIG. In this case, each voltage Va
The currents based on .about.Vd are blocked from passing by the respective switches Sa to Sd controlled to be in the off state.
Accordingly, a current based on the voltage Ve flows through a current path including the winding end terminal of the winding 3e, the capacitors Ca to Cd, the diode 6, and the winding start terminal of the winding 3e, so that the capacitors Ca to Cd The transformer 2b is magnetically reset while being charged. As a result, energy is dispersed and transferred from the capacitor C having the highest voltage between the terminals to the other capacitors C, so that the voltages between the terminals of the capacitors Ca to Cd are averaged to the same voltage.

On the other hand, when the switch S11 is switched to the discharging terminal, each of the capacitors Ca to Cd discharges by supplying a current to the load L. At this time, the switches Sa to Sd are continuously controlled to be turned on / off, whereby the averaging of the terminal voltages of the capacitors Ca to Cd is continuously performed. Therefore, as long as each switch S is on / off controlled, the voltage between terminals of each of the capacitors Ca to Cd is averaged.

Next, a charging / discharging device 31 for charging or discharging while maintaining a capacitor as an energy storage means at different voltages between terminals will be described with reference to FIG.

The charging / discharging device 31 includes a charger 32, a switch S11, and a transformer 2c having three windings 3a, 3b, 3e.
a is connected to both ends of the capacitor C11, and the series circuit of the winding 3b and the switch Sb is connected to the capacitor C12.
Is connected to both ends. In this case, charging and discharging are performed while maintaining the voltage between terminals of the capacitor C11 at A times (A is a positive number) the voltage of the capacitor C12. Therefore, the winding 3a is wound at a turn ratio A times that of the winding 3b, and the winding 3e is wound at a turn ratio (A + 1) times that of the winding 3b. In the charging / discharging device 31, similarly to the charging / discharging device 21, the voltage between the terminals of the capacitor C11 and the capacitance of the capacitor C11 are controlled during the ON state control and the OFF state control of the switch S at the time of charging and discharging.
Twelve terminal voltages are maintained at voltages according to the above equation.

According to the charging / discharging device 31, the capacitors C11 and C12 can be charged or discharged while maintaining the voltages between the terminals different from each other. Note that each of the capacitors C11 and C12 may be configured by a single capacitor, or may be configured by a series or parallel circuit of a plurality of capacitors.

Next, a charging / discharging device 4 according to another embodiment is described.
1 will be described with reference to FIG.

The charging / discharging device 41 has four capacitors Ca
~ Cd, transformer 2b, switches Sa ~ Sd, S11,
Diodes 7a to 7d (hereinafter, when not distinguished,
(Referred to as "diode 7") and a charger 22. In this case, in the charging / discharging device 41, the first to N-th (N is a value of 4) series circuits each including the winding 3 of the transformer 2b and the switch S are connected in series. A reset winding 3e as an (N + 1) th winding is further connected in series, and an (M-1) th winding is connected via an Mth winding 3 (M is an integer of 2 to 5) and a diode 7. The energy stored in the transformer 2b can be released to the capacitor C connected to the winding. The winding numbers Na to Ne of the windings 3a to 3e are wound with the same number of turns, and the capacitors Ca to Cd
Are averaged to the same inter-terminal voltage.
Further, in order to release the excitation energy of the transformer 2b during the off-state control period, each switch S is controlled so that its off-state control period is equal to or longer than the on-state control period.

In the charging / discharging device 41, when the switch S is turned off, the voltage Va induced in the windings 3a to 3e is controlled.
To the capacitor C connected to the (M-1) -th winding via the M-th winding 3 and the diode 7, the excitation energy of the transformer 2b is also released. Each capacitor C is averaged to a voltage according to the above equation. Therefore, in the charging / discharging device 21 described above, each capacitor C is set only when the switch S is turned on.
According to the charging / discharging device 41, the terminal voltage of each capacitor C is averaged both when the switch S is controlled to be on and when the switch S is controlled to be off. You. Therefore, the voltage between the terminals of each capacitor C can be more reliably and quickly averaged.

Next, a charging / discharging device 51 suitable when the voltages between the terminals of the capacitors Ca to Cd are different will be described with reference to FIG.

As shown in FIG.
The transformer 2a is configured such that the reset windings 4a to 4d are connected in series to the respective windings 3a to 3d. In this case, each of the windings 3 and the resetting winding 4 connected in series are wound with the same number of turns, for example, and each of the windings 3a to 3d has a ratio at which the voltage between the terminals of each of the capacitors Ca to Cd satisfies the above expression. The number of turns is Na to Nd.

The charging / discharging device 51 operates basically in the same manner as the operation principle of the transfer device 11. Therefore, each capacitor C is charged or discharged by the output current of the charger 22 so as to be averaged to the terminal voltage according to the above equation.

Next, the merits of charging or discharging while averaging the inter-terminal voltages VCa to VCd of the capacitors Ca to Cd will be described.

The voltage Vc between terminals of the capacitor C is expressed by the following equation, where the charge / discharge current, the charge / discharge time, and the capacity of the capacitor C are I, T and C, respectively. VC = I.times.T / C formula According to this formula, it can be seen that the inter-terminal voltage VC and the capacitance C are in inverse proportion. Therefore, when the capacitance C varies, even when the same current I flows, a capacitor having a large capacitance C has a voltage Vc between its terminals.
Is smaller and the capacitor with the smaller capacitance C is the terminal voltage V
C increases. Therefore, even when charged with the same current for the same time, the capacitor C having a small capacitance C is quickly charged to the rated withstand voltage, and the capacitor C having a large capacitance C is not sufficiently charged.

On the other hand, the stored energy E of the capacitor is
It is expressed by the following equation, and is proportional to the square of the terminal voltage VC. ^{E = C × VC 2/2} ····· formula Thus, the stored energy E is inter-terminal voltage VC be slightly different, it varies greatly. Thus, for example,
In order to sufficiently increase the storage energy E of the driving secondary battery used in an electric vehicle or the like, it is preferable to charge the terminal voltage VC to just below the rated withstand voltage. From this, in particular, a plurality of capacitors having different capacities from each other can be stored in one capacitor.
When charging is performed simultaneously by two charging devices, it is most preferable from the viewpoint of charging efficiency to charge the battery to the rated withstand voltage while averaging the terminal voltage VC. Therefore, it can be said that the merit of charging while averaging the inter-terminal voltages VCa to VCd of the capacitors Ca to Cd is extremely large.

Next, the advantage of averaging the voltage between terminals of a plurality of capacitors having different capacities when discharging the load L from a series circuit of the capacitors will be described.

First, a case in which a series circuit of capacitors C11 and C12 charged to the same voltage and discharged to the load L will be described with reference to FIG. It is assumed that the capacitor C11 shown in FIG. 5A has a larger capacity than the capacitance of the capacitor C12, and as shown in FIG. 5B, at the time of starting discharge to the load L (t = 0).
The terminal voltage VC11 of the capacitor C11 and the capacitor C1
It is assumed that the terminal-to-terminal voltage VC12 is maintained at the same voltage. Therefore, the load terminal voltage VL at this point is maintained at the value (VC11 + VC12 = 2.VC11). On the other hand, the current I1 is discharged to the load L and the time t
When the time reaches 1, the discharging of the small-capacity capacitor C12 ends, and the inter-terminal voltage VC12 becomes 0V. Thereafter, since the current I1 discharged from the capacitor C11 charges the capacitor C12 in the reverse direction, the load terminal voltage VL
Drops rapidly. Next, at the time t2, the load terminal voltage VL becomes 0 V before all the energy stored in the capacitor C11 has been supplied to the load L as shown in FIG. In this state, the capacitor C11
Stored in the capacitors C11 and C12.

On the other hand, in order to prevent the capacitor C12 from being charged in the reverse direction, a diode D1 may be connected in parallel to the capacitor C12 as shown in FIG. In this case, after the time t1 when the discharging of the capacitor C12 is completed, the current I2 discharged from the capacitor C11 flows through the current path including the plus terminal of the capacitor C11, the load L, the diode D1, and the minus terminal of the capacitor C11. Flows. Therefore, since the voltage VC12 between the terminals of the capacitor C12 is limited to the forward voltage VD of the diode D1, reverse charging is prevented. As a result, the load L is more reduced as compared with the circuit of FIG. It can supply a lot of energy. However, in this case, since the current I2 flows through the diode D1,
The power loss due to the diode D1 is wasted.

However, when discharging is performed while averaging the voltages VC11 and VC12 between the terminals of both capacitors C11 and C12, as shown in FIG. 9, the energy release by both capacitors C11 and C12 ends simultaneously at time t3. . Therefore, before the time t3, the capacitor C1
Since the capacitor C12 is not charged with the stored energy of 1, the stored energy of both capacitors C11 and C12 is all efficiently supplied to the load L. Since the energy of the non-uniformity between the capacitors C11 and C12 is directly supplied to the capacitor C12, unnecessary power loss due to the diode D1 of the circuit in FIG. And
In addition, there is an advantage that a sudden drop in the load terminal voltage VL does not occur.

As described above, the charging / discharging devices 21 and 3 described above are used.
According to 1, 41, and 51, the voltage between the terminals of each capacitor C connected in parallel to the series circuit of each winding 3 and the switch S can be charged or discharged while maintaining the voltage according to the above equation. In addition, more energy can be stored in each capacitor C, and energy can be efficiently released from each capacitor C. Further, since the number of circuit components is small, the charging / discharging device can be configured to be small and inexpensive. In addition, since it is only necessary to perform on / off control of each switch S in synchronization, the control can be easily performed. In addition, since a short circuit accident of the capacitor C does not occur, energy can be transferred between the capacitors C with high reliability.

It should be noted that the present invention is not limited to the above-described embodiments of the present invention, and the configuration thereof can be changed as appropriate. For example, in the embodiment of the present invention, the charging / discharging device 21
Although an example has been described above, for example, as shown in FIG. 10, a power storage system S1 can be constructed. In this case, the power storage system S1 includes a battery BA installed in the building A and a charger 2 for charging the battery BA.
2A, a battery BB installed in the building B and having a terminal voltage different from that of the battery BA, a charger 22B for charging the battery BB, and the transfer device 1a. In addition, the transfer device 1a includes windings 3a,
3b, and switches Sa and Sb which are connected in series to both windings 3a and 3b, and which are ON / OFF controlled in synchronization with each other. In the figure,
3 illustrates an ideal circuit. According to the power storage system S1, by controlling the switching of the switches Sa and Sb, the stored energy can be transferred between the batteries BA and BB while the batteries BA and BB are insulated from each other.
For this reason, for example, the charger 22B fails and the battery B
When the charging voltage of B decreases, both batteries BA,
The stored energy of the battery BA can be automatically transferred to the battery BB so that the voltage between both terminals of BB satisfies the above equation.

Further, the transfer device 11 shown in FIG. 2 can be applied to a power supply device. Specifically, for example,
The case where the capacitor Ca is an output-side capacitor of a switching power supply device (not shown) and is stabilized and controlled to a predetermined voltage by the switching power supply device will be described as an example. Conventionally, when generating a plurality of power supply outputs having different voltage values and output current values based on a DC voltage generated by one switching power supply, another switching power supply is further connected to an output-side capacitor of the switching power supply. By doing so, the plurality of power outputs are generated. However, when a forward-type or flyback-type switching power supply is used as another switching power supply, there is a problem in that the circuit becomes complicated and output stability is poor. Also, in the forward type, current flows through the secondary winding of the transformer only when the main switching element is controlled to be in the ON state,
Conversely, in the flyback type, current flows through the secondary winding of the transformer only when the main switching element is controlled to be in the off state. Therefore, both types of switching power supply devices have problems in that the output ripple voltage is large and the peak current is large because the utilization ratio of the secondary winding of the transformer is poor. Furthermore, when a plurality of different switching power supply devices are arranged corresponding to a plurality of power supply outputs, a plurality of switching noises having different frequencies are generated, and a beat between the noises is generated.
There is also a problem in that it is extremely difficult to reduce EMI noise.

In the power supply device using the transfer device 11,
When the capacitor Ca is stably controlled to a predetermined voltage, the stored energy of the capacitor Ca can be easily distributed to the other capacitors Cb to Cd by turning on / off the switches Sa to Sd. Therefore, the voltages VCb to VCd between the terminals of the other capacitors Cb to Cd
Is used as the power supply output voltage, a plurality of power supply outputs having different voltage values and output current values can be easily generated while stabilizing.

In this case, when each switch S is controlled to be turned on, the energy stored in the capacitor Ca is distributed to the capacitors Cb to Cd via the windings 3b to 3c of the transformer 2a, and each switch S is turned off. When the state is controlled, the reset winding 4b of the transformer 2a
To each of the capacitors Cb to Cd through
The stored energy of a is distributed. Therefore, current flows through the windings 3 and 4 of the transformer 2a both when the switches S are controlled to be on and when they are off. As a result, the utilization of the windings 3 and 4 of the transformer 2a becomes extremely high, and the peak current value at that time can be suppressed. As a result, the size of the circuit components can be reduced, and the output ripple voltage can be sufficiently reduced.

Further, regarding the switching noise,
In the power supply device using the transfer device 11, each switch S
Are controlled in synchronization with each other, so that only one type of switching noise is generated. As a result, beat between noises does not occur, and EMI noise can be easily reduced sufficiently. By using FETs or bipolar transistors instead of the diodes 5a to 5d, it is possible to sufficiently reduce power loss during energy distribution.

In the embodiment of the present invention, an electric double-layer capacitor has been described as an example of the energy storage means. However, the present invention is not limited to this.
Various secondary batteries can also be used.

[0059]

As described above, according to the energy transfer device of the first aspect, the energy is transferred between the plurality of energy storage means by performing the switching control in synchronization with the plurality of switch means. Therefore, the control at that time becomes extremely easy. Further, since a short circuit accident does not occur, the energy stored in the energy storage means can be reliably transferred with high reliability. In addition, since it can be configured with the same number of windings and switch means as the energy storage means, the number of circuit components can be reduced, and as a result, the size and cost of the device can be reduced.

According to the energy transfer device of the second aspect, the transformer has the energy discharging winding for discharging the stored energy to the energy storage means. The resulting transformer magnetization can be reliably reset,
Magnetic saturation of the transformer can be reliably prevented.

According to the third aspect of the present invention, the energy discharging windings connected in series to the respective windings transfer the stored energy of the transformer to the energy storage means connected to the corresponding windings. By discharging, the voltage across the energy storage means can be averaged both at the time of magnetizing the transformer and at the time of magnetic reset.

According to the energy transfer device of the fourth aspect, the number of windings for energy emission can be reduced, so that the transformer can be downsized.

According to the energy transfer device of the fifth aspect, the peak value of the current flowing through the winding can be appropriately limited by using the leakage transformer as the transformer.

Further, according to the energy transfer device of the sixth aspect, since the energy storage means is constituted by a secondary battery or a capacitor, for example, in a power storage system or the like, the voltage across the secondary battery or the capacitor is averaged. Therefore, charging and discharging can be performed efficiently.

According to the energy transfer device of the present invention, when averaging the voltages at both ends of the plurality of energy storage means to the same voltage, the transformer is constituted by the same number of windings so that the transformer is formed. It can be manufactured at low cost.

According to the energy transfer device of the present invention, since the switch means is constituted by a field effect transistor or a bipolar transistor, the switch means can be constituted at a low cost and the power loss at the time of switching can be reduced. Can be reduced.

According to the charging device of the ninth aspect,
Since the voltage between both ends of the plurality of objects to be charged can be equalized by the energy transfer device, energy can be efficiently stored in the objects to be charged.

Further, according to the power supply device of the tenth aspect, by distributing the energy stored in one predetermined energy storage means to the other energy storage means, a plurality of power supplies having different voltage values and output current values are provided. Power supply output can be easily generated. Further, since the utilization factor of the winding can be increased, the peak current value at the time of energy distribution can be suppressed. As a result, the size of circuit components can be reduced, and the output ripple voltage can be sufficiently reduced. can do. Further, regarding the switching noise, since the switching control is performed in synchronization with each switch S, the generation of the beat between the noises is prevented while the EMI is suppressed.
Noise can be sufficiently reduced.

According to the power supply device of the eleventh aspect, since the voltage between any one of the plurality of energy storage means is stably controlled to a predetermined voltage, the voltage value and the output current value are different. In addition, a plurality of stabilized power outputs can be easily generated.

[Brief description of the drawings]

FIG. 1 shows a transfer device 1 for explaining the operation principle of the present invention.
FIG.

FIG. 2 is a circuit diagram of the transfer device 11 according to the embodiment of the present invention.

FIG. 3 is a circuit diagram of a charge / discharge device 21 according to the embodiment of the present invention.

FIG. 4 is a charge / discharge device 31 according to another embodiment of the present invention.
FIG.

FIG. 5 is a circuit diagram of a charging / discharging device 41 according to still another embodiment of the present invention.

FIG. 6 is a circuit diagram of a charge / discharge device 51 according to still another embodiment of the present invention.

FIG. 7 shows a voltage VC11 between terminals of capacitors C11 and C12.
, VC12 are averaged, (a) is a circuit diagram in which a load L is connected to capacitors C11 and C12, and (b) is a diagram illustrating both capacitors C11 and C12.
FIG. 4 is a voltage characteristic diagram showing discharge characteristics of the present invention.

FIG. 8 shows a voltage VC11 between terminals of capacitors C11 and C12.
, VC12 are averaged, and FIG. 7A is a diagram for connecting a load L to the capacitors C11 and C12 and connecting a diode D to both ends of the capacitor C12.
1 (b) is a circuit diagram in which both capacitors C1 are connected in parallel.
1 is a voltage characteristic diagram showing discharge characteristics of C1 and C12.

FIG. 9 shows a voltage VC1 between terminals of both capacitors C11 and C12.
1 is a voltage characteristic diagram showing discharge characteristics when VC12 is averaged.

FIG. 10 is a system configuration diagram of a power storage system S1.

FIG. 11 is a circuit diagram of a conventional transfer device 61.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transfer device 1a Transfer device 2, 2a-2d Transformer 3a-3e Winding 4a-4d Reset winding 7a-7d Diode 21,31,41,51 Charge / discharge device 22,22A, 22B, 32 Charger BA, BB Battery Ca-Cd, C11, C12 Capacitor S1 Power storage system Sa-Sd Switch

Claims (11)

[Claims] 1. A plurality of series circuits each having at least a winding and a switch means connected in series, and each of the plurality of series circuits is configured to be connectable in parallel to each of a plurality of energy storage means, respectively. The energy transfer device according to claim 1, wherein the windings are magnetically coupled to each other, and the plurality of switch units are switching-controlled in synchronization with each other. And a transformer having a plurality of windings, wherein the transformer discharges energy stored in the transformer to the energy storage means when the switch means is turned off. The energy transfer device according to claim 1, further comprising: 3. The energy discharging winding is connected in series to each of the windings, and each of the energy discharging windings is connected to the energy storage means connected to the corresponding winding. The energy transfer device according to claim 2, wherein the stored energy is released. 4. A first to an N-th series circuit (N is an integer) each composed of said winding and said switch means are connected in series, and said series-connected circuit serves as an (N + 1) -th winding. The energy emitting winding is further connected in series, and connected to the (M-1) th winding via the M-th winding (M is an integer of 2 or more and (N + 1) or less) and a unidirectional element. 3. The energy transfer device according to claim 2, wherein said energy storage means is configured to be capable of discharging stored energy of said transformer. 5. The energy transfer device according to claim 2, wherein the transformer is a leakage transformer. 6. The energy storage device according to claim 1, wherein the energy storage means is a secondary battery or a capacitor.
An energy transfer device according to any one of the above. 7. The energy transfer device according to claim 1, wherein the windings are formed with the same number of turns. 8. The energy transfer device according to claim 1, wherein said switch means comprises a field effect transistor or a bipolar transistor. 9. An energy transfer device according to claim 1, wherein said series circuit is configured to be connected in parallel to both ends of each of a plurality of objects to be charged. Charging device. 10. An energy transfer device according to claim 1, wherein said plurality of energy storage means are each constituted by a capacitor or a battery, and each of said plurality of energy storage means is a predetermined one of said energy storage means. A power supply device for distributing stored energy to other energy storage means. 11. The power supply device according to claim 10, wherein the voltage between any one of the plurality of energy storage means is stably controlled to a predetermined voltage.