JP3280635B2 - Energy transfer device and power storage system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is connected to a plurality of energy storage means, Oyo energy transfer device for transferring energy between the energy storage means mutually
It relates fine power storage system, and more particularly to a energy transfer device and the power storage system suitable for averaging the voltage across the plurality of energy storage means.

[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 energy stored in 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. As a result, 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, a 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] Also, the capacitor C4 is
Switches SW4 to SW1 when transferring energy to
Must be controlled on and off many times with precise timing. For this reason, the transfer device 61 also has a problem that the control of the switches 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.

[0007] The present invention has been made to solve the above problems, it can be transported surely and easily energy has high reliability, energy transfer devices and can be configured compact and inexpensive addition The main purpose is to provide a power storage system .

[0008]

According to a first aspect of the present invention, there is provided an energy transfer device capable of transferring energy between first to Nth (N is an integer of 2 or more) energy storage means. An energy transfer device comprising: a leakage transformer having first to N-th windings; and first to N-th switch means, each of which is switching-controlled in synchronization with each other, and wherein an L-th (L is 1 to N) and the L-th switch means are connected in series with each other, so that a series circuit can be connected in parallel to the L-th energy storage means .
And the leakage inductance of the leakage transformer
Through the first through Nth energies
Energy is characterized Rukoto are transported between over storage means another. 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. Also,
The energy storage means is constituted by a secondary battery or a capacitor. The secondary battery includes a lithium ion battery, a lithium polymer battery, and the like, and the capacitor includes an electric double layer capacitor and the like. Further, the switch means is constituted by a field effect transistor or a bipolar transistor.

According to a second aspect of the present invention, in the energy transfer device of the first aspect, the first to N-th energy storage means are connected in series, and the leakage transformer includes an energy discharge winding. Further equipped with lines,
Magnetic reset is performed by a magnetic reset circuit including an energy discharging winding and a unidirectional element, and the magnetic reset circuit is unidirectional in a direction in which a current for charging the first to Nth energy storage units is passed. A first element connected in series with an energy emitting winding and connected in series with the energy emitting winding.
To Nth energy storage means.

According to a third aspect of the present invention, there is provided the energy transfer device according to the first aspect, wherein the first to Nth energy transfer devices are provided.
Energy storage means are connected in series, the leakage transformer further comprises an (N + 1) th winding,
Magnetically reset by a magnetic reset circuit including second to (N + 1) th windings and first to Nth unidirectional elements;
The magnetic reset circuit is a first to N-th series circuits in which an L-th unidirectional element is connected in series to an (L + 1) -th winding in a direction for passing a current for charging an L-th energy storage means. And the L-th series circuit is connected to both ends of the L-th energy storage means.

According to a fourth aspect of the present invention, there is provided the energy transfer device according to the first aspect, wherein
Energy storage means are connected in series, and the leakage transformer further includes first to N-th energy discharging windings connected in series to the first to N-th windings, respectively. Is magnetically reset by a magnetic reset circuit including the first energy release winding and the first to Nth unidirectional elements, and the magnetic reset circuit passes a current for charging the Lth energy storage means. L-direction unidirectional elements are connected in series to the L-th energy emission winding, and are configured by first to N-th series circuits, and the L-th series circuit is provided at both ends of the L-th energy storage means. It is characterized by being connected.

According to a fifth aspect of the present invention, in the energy transfer device according to any one of the first to fourth aspects, the first to N-th windings are each configured with the same number of turns. And

According to a sixth aspect of the present invention, there is provided a power storage system comprising:
N (N is an integer of 2 or more) energy storage means;
To at least one end of each of the Nth energy storage means
Are not connected between each energy storage means
Energy transfer device configured to transfer energy
And an energy transfer device.
Is synchronized with the transformer having the first to Nth windings.
And the first to Nth switches, each of which is switching-controlled.
L-th (L is 1 to N) winding means
Series circuit comprising a line and L-th switch means connected in series
In parallel with the L-th energy storage means.
When each switch means is on, current flows through each winding.
The first to Nth energy storage means phases by flowing
It is characterized by transferring energy between each other.

According to a seventh aspect of the present invention, there is provided a power storage system.
In the power storage system described above, the transformer includes first to Nth
To the N-th energy respectively connected in series to the
-Further comprising a winding for discharging the first to Nth energy
A magnetic coil comprising an output winding and first to Nth unidirectional elements.
Magnetic reset by the set circuit
The circuit passes a current that charges the Lth energy storage means.
The Lth unidirectional element in the Lth energy
Consists of 1st to Nth series circuits connected in series to the discharge winding
And the L-th series circuit is connected to the L-th energy storage means.
It is characterized by being connected to both ends.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an energy transfer device and a power storage system according to 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”
It is 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). It is assumed that 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. The windings 3a to 3d are magnetically coupled to each other by an iron core, and the number of windings Na, Nb,
It is wound by Nc and Nd, respectively. Further, the transfer device 1 includes switches Sa to Sd (hereinafter, when not distinguished, “switch S” connected between the winding end side ends of the windings 3a to 3d and the negative terminals of the capacitors Ca to Cd, respectively. ). in this case,
Each of the switches Sa to Sd is composed of, for example, an FET or a bipolar transistor, and is turned on / off in synchronization with each other by a switching control circuit (not shown).

In this transfer device 1, the winding start side ends of the windings 3 and the fixed contacts of the corresponding switches 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 controlled to be turned on, only the voltage VCa between the terminals of the capacitor Ca is higher than the voltage according to the above equation, so the plus terminal of the capacitor Ca, the winding 3a, the switch Sa and 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 terminals of the capacitor Ca is generated in the winding 3a, and a voltage Vb having a value corresponding to a 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, each of the voltages Vb to Vd is higher than the corresponding inter-terminal voltage 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 by 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 the 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, the number of windings 3 and the number of switches S can be the same as that of the energy storage means, so that the number of circuit components can be reduced. A low price can be achieved. Further, since it is only necessary to perform switching control synchronously with the switches Sa to Sd, the control is facilitated, and a short circuit accident is not caused.
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 emitting 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 respectively 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
When d is on, 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 in the same manner as in the transfer device 1, whereby each of the capacitors Ca to Voltage VCa between each terminal of Cd
Energy is transferred so that ~ VCd satisfies the above equation. On the other hand, since the exciting current flows in the actual transformer 2a, when the switch S is turned on , the transformer 2a is magnetized. Then, sometimes off of the switch Sa~Sd,
As shown in the figure, voltages Va to Vd and VA to VD are generated in the windings 3a to 3d and the reset windings 4a to 4d, respectively. 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 via the capacitor C and the diode 5, respectively.
In this case, 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 off , energy is transferred from the capacitor C having a voltage higher than the voltage satisfying the above expression to another capacitor C,
Each terminal voltage VCa to VCd satisfies the above equation. When the turns ratio of each winding 3 is the same, the voltages VCa to VCd between the terminals of the capacitors Ca to Cd can be easily averaged to the same voltage. In addition, the ratio (NA
When / Na) is set to a value of 1, the switch S is switched at a 50% duty, so that the excitation energy of the transformer 2a is theoretically all discharged within the off period of the switch S. As a result, magnetic saturation of the transformer 2a is reliably prevented.

The leakage transformer is connected to the transformer 2a.
When the current flows through each winding 3 when the switch S is turned on, 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 (N is an integer of 2 or more) series-connected capacitors or a secondary battery (a composite product in which a capacitor and a secondary battery are mixed) serving 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 having the same capacity is used as 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
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, the switching control is performed in synchronization with each other only when discharging from the capacitor C to the load L, and is controlled to the off state when charging or discharging is not performed. Further, the switch S1
In 1, 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 a current path including the positive terminal of the capacitor C, the winding 3, the switch S, and the negative terminal of the capacitor C. As a result, 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.
Therefore, 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, the 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 the 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 turned at (A + 1) times the turns ratio of the winding 3b. In this rechargeable device 31, similarly to the discharge apparatus 21, at the time of charging and discharging, during the time and off of the switch S is turned on, the voltage between the terminals of the terminal voltage and the capacitor C12 of the capacitor C11, The voltage is maintained according to the above equation.

According to the charging / discharging device 31, it is possible to charge or discharge the capacitors C11 and C12 while maintaining the voltages between the terminals different from each other. Each of the capacitors C11 and C12 may be configured by one 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 includes four capacitors Ca
To Cd, transformer 2b, switches Sa to Sd, S11,
Diodes 7a to 7d (hereinafter, when not distinguished,
"Diode 7") and a charger 22. In this case, in the charging / discharging device 41, the first to Nth (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, and 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.
Each switch S, in order to release the excitation energy of the transformer 2b within a period of off, it is assumed that the period of the off is equal to the period of ON is controlled to be longer.

[0037] In the charge and discharge device 41, switch S Gao
At the time of the voltage change, the voltages Va to Ve induced in the windings 3a to 3e.
Is connected to the (M−1) th winding via the Mth winding 3 and the diode 7.
In this case, the excitation energy of the transformer 2b is released, and also at this time, each capacitor C is averaged to a voltage according to the above equation. Therefore, in the charge / discharge device 21 described above,
While switch S is averaged only voltage between the terminals of the capacitor C when on, according to the charge and discharge device 41, in both time when the time switch S is turned on and off, the capacitor C Are averaged. 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 has a configuration in which reset windings 4a to 4d are connected in series to respective windings 3a to 3d. In this case, each of the windings 3 and the resetting winding 4 connected in series are wound, for example, with the same number of turns, 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 terminal voltage VC 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 terminal voltage VC and the capacitance C are in inverse proportion. Therefore, when the capacitance C varies, even if 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 the capacitor C is charged with the same current for the same time, the capacitor C having a small capacity C is quickly charged to the rated withstand voltage, and the capacitor C having a large capacity 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. So, for example,
In order to sufficiently increase the stored 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. For this reason, a plurality of capacitors having different capacities from each other can be used.
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 voltages between the terminals of a plurality of capacitors having different capacities when discharging the load L from a series circuit of different 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 a 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.
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 time 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 discharge 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 0V 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 with 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. Accordingly, since the voltage VC12 between the terminals of the capacitor C12 is limited to the forward voltage VD of the diode D1, the 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 the voltage is discharged 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, all the stored energy of the capacitors C11 and C12 is efficiently supplied to the load L. Further, 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 a merit 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, it is possible to charge or discharge while maintaining the voltage between the terminals of each capacitor C connected in parallel to the series circuit of each winding 3 and the switch S at a 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. Moreover, 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 embodiment of the invention, and the configuration 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 also 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 the two windings 3a and 3b and which are ON / OFF controlled in synchronization with each other. In the figure,
2 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 being insulated from each other.
Therefore, 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,
An example in which the capacitor Ca is an output-side capacitor of a switching power supply (not shown) and is controlled to be stabilized at a predetermined voltage by the switching power supply will be described. 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, a current flows through the secondary winding of the transformer only when the main switching element is controlled to be turned off. Therefore, both types of switching power supply devices have a problem 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. Further, when a plurality of different switching power supply devices are provided 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 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 capacitor Cb to Cd through
The stored energy of a is distributed. Thus, each switch S in both time when the time and off-on, will flow the windings 3 and 4 of the transformer 2a current. 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 circuit components can be reduced in size, 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, there is no beat between noises, and it is easy to sufficiently reduce EMI noise. 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.

[0055]

As described above, according to the energy transfer device of the first aspect, by controlling the switching of the N switch means in synchronization with each other, a plurality of energy storages can be performed via the N windings. Since energy can be transferred between the means, control at that time becomes extremely easy. Further, since a short circuit accident does not occur, the stored energy of the energy storage means can be reliably transferred with high reliability. In addition, since it can be constituted by 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. In addition, since the N windings are wound around the leakage transformer, the current flows through the leakage inductance of the leakage transformer when the current flows through each winding when the switch means is turned on . The peak value can be limited appropriately. In this case , by magnetically resetting the leakage transformer when the switch is turned off, magnetic saturation of the leakage transformer can be reliably prevented.

According to the energy transfer device of the present invention, the energy stored in the leakage transformer is released to the energy storage means via the energy discharging winding and the one-way element, so that a current is supplied to the winding. The magnetization of the transformer caused by the flow can be reliably reset, and thereby the magnetic saturation of the transformer can be reliably prevented. Further, since the number of windings for energy emission can be reduced, the size of the transformer can be reduced.

Further, according to the energy transfer device of the third aspect, the first to Nth series circuits release the stored energy of the leakage transformer to the first to Nth energy storage means, respectively, so that the switching means is provided. There in both time when the oN <br/> time and off, since the terminal voltage of the energy storage means of the first to N are averaged, the first to
The voltage between the terminals of the N-th energy storage means can be more reliably and quickly averaged.

According to the fourth aspect of the present invention, the first to Nth energy discharging windings connected in series to the first to Nth windings are connected to the corresponding windings. By discharging the stored energy of the leakage transformer to the stored energy storage means, the voltage across the energy storage means can be averaged both at the time of magnetization of the leakage transformer and at the time of magnetic reset.

According to the fifth aspect of the present invention, when averaging the voltages across the plurality of energy storage means to the same voltage, the first to N-th windings have the same number of turns. By doing so, the transformer can be manufactured at low cost.

Furthermore, according to the power storage system of claim 6,
Then, for example, the battery B installed in the building A
A and the end installed in building B and different from battery BA
The battery with the child voltage is insulated from the battery BB.
Energy can be transferred between each other.

Further , according to the power storage system of claim 7,
For example, the first to Nth windings connected in series to the first to Nth windings, respectively.
The Nth energy emitting winding is connected to the corresponding winding.
Energy stored in the transformer
Each time the transformer is magnetized,
Energy storage during both magnetic and magnetic resets.
The voltage across the product means can be averaged.

[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 charging / discharging 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 charging / discharging 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 the discharge characteristics of FIG.

FIG. 8 shows a voltage VC11 between terminals of capacitors C11 and C12.
, VC12 are averaged, and FIG. 10A is a diagram for connecting a load L to 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

Continuation of front page (56) References JP-A-59-228421 (JP, A) JP-A-60-106363 (JP, A) JP-A-60-106364 (JP, A) JP-A-60-204265 (JP) JP-A-62-196071 (JP, A) JP-A-1-321860 (JP, A) JP-A-3-27772 (JP, A) JP-A-5-159755 (JP, A) JP-A-6-78537 (JP, A) JP-A-6-86548 (JP, A) JP-A-6-261451 (JP, A) JP-A-6-261546 (JP, A) JP-A-7-322516 (JP, A A) JP-A-10-52042 (JP, A) JP-A-10-84627 (JP, A) JP-A-11-103534 (JP, A) JP-A-11-103535 (JP, A) U.S. Pat. US, A) US Pat. No. 5,664,041 (US, A) US Pat. No. 5,767,660 (US, A) US Pat. No. 5,821,729 (US, A) US Pat. 432639 (EP, A2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 30/02 H01M 2/00-2/08 H01M 10/42-10/48 H02J 1/00-1/16 H02J 7/00-7/12 H02J 7/34-7/36 H02J 15/00 H02M 3/24-3/338

Claims (7)

(57) [Claims] 1. An energy transfer device configured to transfer energy between first to Nth (N is an integer of 2 or more) energy storage means, comprising: first to Nth windings. A leakage transformer and first to N-th switching control units which are respectively controlled in synchronization with each other.
Switch means, and a series circuit formed by connecting the L-th (L is each of 1 to N) winding and the L-th switch means in series can be connected in parallel to the L-th energy storage means. When each of the switch means is on,
Leakage of each winding and the leakage transformer
The current flows through the inductance
Between the first to Nth energy storage means.
Energy energy transfer device, characterized in Rukoto is transferred is. 2. The leakage transformer according to claim 1, wherein the first to Nth energy storage means are connected in series.
It further includes an energy emitting winding, and is magnetically reset by a magnetic resetting circuit including the energy emitting winding and the one-way element, and the magnetic resetting circuit includes:
The unidirectional element is configured to be connected in series to the energy discharging winding in a direction in which a current for charging the first to Nth energy storage means passes, and the first to Nth serially connected elements are connected in series. The energy transfer device according to claim 1, wherein the energy transfer device is connected to both ends of the energy storage means. 3. The leakage transformer according to claim 1, wherein the first to N-th energy storage units are connected in series.
A second (N + 1) -th winding;
Magnetic reset is performed by a magnetic reset circuit including the winding of 1) and the first to Nth unidirectional elements, and the magnetic reset circuit passes a current that charges the L-th energy storage unit. A first to an N-th series circuit in which the L-th unidirectional element is connected in series to the (L + 1) -th winding in the direction in which the L-th energy storage is performed. The energy transfer device according to claim 1, wherein the energy transfer device is connected to both ends of the means. 4. The leakage transformer according to claim 1, wherein the first to Nth energy storage means are connected in series.
The first to Nth windings connected in series to the first to Nth windings, respectively.
The apparatus further includes an N-th energy discharging winding,
Magnetic reset is performed by a magnetic reset circuit including an N-th energy emitting winding and first to N-th unidirectional elements, and the magnetic reset circuit charges the L-th energy storage unit. The L-th
Are connected in series to the L-th energy emission winding, and are configured by first to N-th series circuits.
The energy transfer device according to claim 1, wherein the series circuit is connected to both ends of the L-th energy storage means. 5. The apparatus according to claim 1, wherein the first to N-th windings have the same number of turns.
An energy transfer device according to any one of the above. 6. The first to Nth (N is an integer of 2 or more) energy sources.
Energy storage means and the first to Nth energy storage means.
Each of the stages has at least one end disconnected from each other.
Energy can be transferred between energy storage means
Power storage system with energy transfer device
A beam, said energy transfer device includes a winding of the first to N
Switching control synchronized with transformer and each other
First to Nth switch means, and
(L is each of 1 to N) windings and the L-th switch
Means in series with the L-th energy
Energy storage means so that they can be connected in parallel.
Current flows through each winding when the switch is on.
Between the first to Nth energy storage means
Transferring the energy at
Electrical system. 7. The transformer according to claim 1 , wherein the first to Nth windings are
First to N-th energy emission respectively connected in series
The first to Nth energy release
Magnetic recess comprising a winding for use and first to Nth unidirectional elements
Magnetic reset by the reset circuit
Circuit for charging the L-th energy storage means.
The L-th unidirectional element in the direction in which
The first to Nth N series connected to the L energy discharging winding
The L-th series circuit is composed of a series circuit.
Characterized by being connected to both ends of the energy storage means
The power storage system according to claim 6.