JP2001286072A - Device making voltage uniform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable, inexpensive, and compact device for making voltage uniform that makes the voltage between the terminals of a plurality of rechargeable elements uniform securely and easily. SOLUTION: A device 11 for making uniform the voltage between the terminals of rechargeable elements C1 to C3 to nearly the same voltage by supplying energy to each of the rechargeable elements C1 to C3 that are connected in series is equipment with a transformer 2 that has input winding 2a that is connected to a DC power supply CH, and output windings 2b to 2d that are wound to nearly the same number of turns, a switching S1 that is connected to the input winding 2a in series, a plurality of one-directional elements D1 to D3 that are connected between the output windings 2b to 2d and the rechargeable elements C1 to C3 for supplying the accumulation energy of a transformer 2 to the rechargeable elements C1 to C3, and a voltage detection means 13 for detecting the voltage between the terminals a plurality of rechargeable elements that are connected in series.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage uniforming device for supplying energy to each of a plurality of storage elements connected in series to equalize voltages between terminals of the plurality of storage elements to substantially equal voltages. The present invention relates to a gasifier.

[0002]

2. Description of the Related Art As a voltage equalizing device of this type, for example, a voltage equalizing device described in Japanese Patent Application Laid-Open No. 7-322516 has been conventionally known. As shown in FIG. 4, the voltage equalizing device 31 transfers the stored energy of any one of a plurality of capacitors C1 to C4 connected in series to another capacitor by transferring the stored energy to another capacitor.
The voltage between terminals 1 to C4 can be made uniform.
Specifically, the voltage equalizing device 31 includes a choke coil L1 and a switch SW connected in parallel with the capacitor C1.
1, a switch SW21 connected to a capacitor C2 via a choke coil L1, and a capacitor C
2, a series circuit of the choke coil L2 and the switch SW22 connected in parallel to the capacitor C3, a series circuit of the choke coil L3 and the switch SW31 connected in parallel to the capacitor C3, and a switch SW32 connected to the capacitor C3 via the choke coil L2. , And a switch SW4 connected to the capacitor C4 via the choke coil L3.

In the voltage equalizing device 31, 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 I31 flows to excite the choke coil L3 as shown in FIG. Then
By simultaneously controlling the switch SW4 and the switch SW31 to the off state and the on state, respectively, the current I32 based on the excitation energy of the choke coil L3 flows, and the capacitor C3 is charged. Next, switch SW
After the switch 31 is turned off, the switch SW32 is turned on. Thus, the current I33 flows to excite the choke coil L2. Subsequently, by simultaneously controlling the switch SW32 and the switch SW22 to the off state and the on state, respectively, the current I34 based on the excitation energy of the choke coil L2 flows, and the capacitor C2 is charged. Then, switch SW
After the switch 22 is turned off, the switch SW21 is turned on. As a result, the current I35 flows to excite the choke coil L1. Finally, by simultaneously controlling the switch SW21 and the switch SW1 to the off state and the on state, respectively, the current I36 based on the excitation energy of the choke coil L1 flows, and the capacitor C1 is charged. As a result, the capacitor C
4 is transferred to the capacitor C1.

[0004]

However, the conventional voltage equalizing device 31 has the following problems. That is, in the voltage equalizing device 31, for example, the capacitor C4
When transferring energy from the capacitor C3 to the capacitor C3, it is necessary to simultaneously control the switches SW4 and 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 are short-circuited via the switches SW4 and SW31, so that the energy stored in the capacitors C3 and C4 is lost. . On the other hand, prior to the ON state of the switch SW31, the switch S
When the switch W4 is turned off, an extremely high voltage is generated across the switch SW4.
4 is damaged. Thus, the conventional voltage equalizing device 31
However, if the timing of the switching control of the switches S1 to SW4 is slightly deviated, there is a problem that a short circuit of a circuit or damage of a circuit component 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 controlled many times with precise timing. In particular, in order to equalize the voltage between the terminals of all the capacitors C1 to C4, the capacitors C1 to C4
Since a very large number of switching controls are required among the four devices, the voltage equalizing device 31 also has a problem that the control of the switches is complicated. In addition, there is a problem that the process of calculating the amount of energy to be transferred between the capacitors C1 to C4 in order to equalize the voltage between the terminals of the capacitors C1 to C4 is very complicated.

Further, in the voltage equalizing device 31, it is necessary to use six switches SW1 to SW4 in order to transfer 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, the conventional voltage equalizing device 31 has a problem that the number of switches is large, and the device is expensive and large.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has high reliability, can reliably and easily equalize voltages between terminals of a plurality of power storage elements, and is inexpensive and compact. It is a main object to provide a voltage equalizing device that can be configured.

[0008]

In order to achieve the above object, a voltage equalizing apparatus according to the present invention supplies energy to each of a plurality of storage elements connected in series, thereby providing a voltage between terminals of each storage element. A transformer having an input winding connected to a DC power supply and a plurality of output windings wound with substantially the same number of turns, and a series connection to the input winding. Switch means, a plurality of unidirectional elements each connected between each output winding and each storage element and capable of supplying the storage energy of the transformer to the storage element, and a plurality of storage elements connected in series. Voltage detecting means for detecting the voltage between the terminals. Note that the storage element in the present invention includes a capacitor and a secondary battery. In this case, the capacitor includes an electric double layer capacitor and the like, and the secondary battery includes a lithium ion battery and a lithium polymer battery. In addition, the unidirectional element includes a diode, a field effect transistor, a bipolar transistor, and the like, and the switching means includes a field effect transistor, a bipolar transistor, and the like.

In this case, the switching means starts switching when the variation of the voltage between the terminals of the plurality of power storage elements falls outside a predetermined voltage range based on the detection result of the voltage detecting means, and the variation of the voltage between the terminals. It is preferable that the switching is stopped when is within a predetermined voltage range. In addition, the switch means, when the voltage between any one or more terminals of the plurality of power storage elements reaches a predetermined voltage set based on the maximum chargeable voltage of the power storage element based on the detection result of the voltage detection means. Preferably, the switching is stopped.

Further, the voltage equalizing device according to the present invention supplies energy to each of a plurality of power storage elements connected in series, thereby equalizing the voltage between terminals of each power storage element to a voltage substantially equal to each other. In the equalizing apparatus, a transformer having an input winding connected to a DC power supply and a plurality of output windings wound with substantially the same number of turns, switch means serially connected to the input winding of the transformer, A plurality of unidirectional elements connected between the respective output windings and the respective storage elements and capable of supplying the storage energy of the transformer to the storage elements, and are supplied to the respective storage elements via the respective unidirectional elements. Current detecting means for detecting a current.

In this case, it is preferable that the switching means stops the switching when the variation of the current supplied to each power storage element is within a predetermined range based on the detection result of the current detecting means. Further, when the switching means is intermittently switched, based on the detection result of the current detecting means, when the variation is determined to be within a predetermined range, the switching means is controlled to an off state, and when it is determined that the deviation is out of the predetermined range. It is further preferable to provide a control circuit for continuing the switching to the switch means.

Further, the DC power supply can be constituted by a plurality of storage elements. Further, it is preferable that a charging function unit that directly charges a plurality of power storage elements connected in series is further provided. Further, it is more preferable that the one-way element is constituted by a diode.

[0013]

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

First, the basic operation principle of the voltage equalizing device according to the present invention will be described with reference to FIG.

As shown in FIG. 1, the voltage equalizing apparatus 1 comprises:
For example, three batteries B1 to B3 (hereinafter, referred to as chargeable power storage elements) directly charged by a charger (not shown)
When no distinction is made, the voltages VB1, VB2, VB3 between the terminals of the "battery B" (hereinafter referred to as "the voltage VB between the terminals when not distinguished") can be made uniform. Specifically, the voltage equalizing device 1 includes a winding 2a having the number of turns N1 functioning as an input winding and a winding number N2 equal to the number of turns N2.
Three windings 2b which are wound by and function as output windings
To 2d are provided with a transformer 2 magnetically coupled to each other by an iron core. This transformer 2 has leakage inductance and functions as a so-called flyback transformer. Further, the voltage equalizing device 1 includes a switch S1 corresponding to the switch unit in the present invention. The switch S1 is composed of, for example, an FET or a bipolar transistor, and switching is controlled by a switching control circuit (not shown). Also,
Equivalently, one end of the switch S1 is connected to the winding end terminal of the winding 2a, and the other end is connected to the minus output terminal of the DC power supply PS. Further, the voltage equalizing device 1 includes three diodes D1 to D3 each having an anode connected to the winding end terminal of each of the windings 2b to 2d.
(Hereinafter referred to as "diode D" when not distinguished)
It has.

Next, the operation of the voltage equalizing device 1 will be described. First, the winding start side terminal of the winding 2a is connected to the DC power supply PS.
And the other end of the switch S1 is connected to the negative output terminal of the DC power supply PS.
The cathodes of the diodes D1 to D3 and the batteries B
1 to B3 plus terminals, respectively,
Each winding start side terminal of each winding 2b-2d, and each battery B1-B
3 is connected to the negative terminal. Next, the switch S1 is turned on / off. In this case, when the switch S1 is turned on, as shown in FIG. 1, the plus output terminal of the DC power supply PS, the winding 2a, and the switch S
1, and a current path formed by the negative output terminal of the DC power supply PS is a current I based on the output voltage VIN of the DC power supply PS.
IN flows. At this time, the diodes D1 to D3 prevent the current from being released from the windings 2b to 2d.
The energy is stored in the transformer 2 by the current IIN flowing through a.

Next, when the switch S1 is controlled to be turned off, a voltage VO is induced in each of the windings 2b to 2d to release the energy stored in the transformer 2. In this case, the voltage VO is a voltage at which energy can be released to the battery B having the lowest terminal voltage VBMIN among the batteries B (more precisely, the voltage obtained by adding the forward voltage of the diode D to the terminal voltage VBMIN). And the exciting energy of the transformer 2 is discharged to the battery B. Therefore, the voltage VO stops rising and is clamped at that voltage. At the same time, one of the plurality of windings 2b to 2d is clamped to that voltage and the number of turns of each winding 2b to 2d is equal to each other, so that all windings 2b to 2d have the same voltage. As a result, for example, assuming that the terminal voltage VB of the battery B1 is the lowest voltage, initially, the current I1 based on the voltage VO induced in the winding 2b is initially supplied to the winding end terminal of the winding 2b, the diode D1, and the battery D1. B1 and a current path composed of a winding start terminal of the winding 2b. Next, when the terminal voltage VB of the battery B1 rises to a voltage equal to the terminal voltage VB of the other battery B, the current I2,
I3 flows sequentially, whereby the voltage VB between the terminals of each battery B is equalized.

As described above, according to the voltage equalizing apparatus 1, one switch S1, a transformer 2 having approximately the same number of windings 2a to 2d as the battery B as a storage element, and the same number of diodes as the battery B D, the number of circuit components can be reduced, and as a result, the size and cost of the device can be reduced. Further, the terminal voltages VB of the plurality of batteries B can be automatically equalized by only turning on / off one switch S1, thereby facilitating the switching control. in addition,
Since a short circuit accident does not occur, the voltage equalizing process for the terminal voltage VB of each battery B can be performed reliably and with high reliability. The voltage equalizing device 1 is not intended to supply the currents I1 to I3 to directly charge the batteries B1 to B3. This is because, when the batteries B1 to B3 are to be directly charged by the voltage equalizing device 1, when the currents I1 to I3 are supplied to the batteries B1 to B3, losses due to the diodes D1 to D3 occur. The reason is that the charging efficiency is reduced. Therefore,
Preferably, each of the batteries B1 to B3 is directly charged by a charger, and when the inter-terminal voltages VB1 to VB3 vary, it is preferable that the voltages are equalized by the voltage equalizing device 1.

Next, a voltage equalizing apparatus 11 according to another embodiment will be described with reference to FIG. Note that
The same components as those of the voltage equalizing device 1 are denoted by the same reference numerals, and redundant description will be omitted, and redundant description of the same operation will be omitted.

First, the configuration of the voltage equalizing device 11 will be described. As shown in FIG.
Is different from the voltage equalizing device 1, the winding start side terminal of the winding 2a and the other end of the switch S1 are connected to the plus side terminal of the battery B1 and the minus side terminal of the battery B3, respectively. Further, the voltage equalizing device 11 includes a switch S1
Switching control circuit 12 for controlling the switching of
And a start control circuit 13 for detecting the voltage VB between the terminals of each battery B and controlling the start of the switching control circuit 12 based on the detection result. Further, each of the batteries B1 to B3
Is connected to a charging function unit CH.
Supplies a DC voltage to the battery B to directly charge the battery. In the voltage equalization device 11, unlike the voltage equalization device 1, the energy output from the charging function unit CH or the stored energy itself of the batteries B1 to B3 is used as the energy for equalization instead of the DC power supply PS. A usable configuration is employed. Therefore, for example, when each battery B is a car battery, and when no energy is supplied from the charging function unit CH in a state where the engine is stopped, such as when parking, the batteries B1 to B1.
By using the stored energy of B3, the process of equalizing the voltage between terminals in each battery B can be continued. Further, since the energy output from the charging function unit CH connected to each battery B can also be used for the energy for voltage equalization, the DC power supply PS becomes unnecessary, so that the size and cost of the device can be reduced. Can be planned.

Next, the operation of the voltage equalizing device 11 will be described. First, the output terminal and the ground terminal of the charging function unit CH are connected to the plus terminal of the battery B1 and the minus terminal of the battery B3, respectively. Next, the charging function unit C
H starts charging the batteries B1 to B3. At this time, in the voltage equalizing device 11, the start control circuit 13
Input the terminal voltages V1 to V3 of the positive terminals of the batteries B1 to B3 with respect to the ground potential VE, and input the respective terminal voltages V1 to V3.
1 to V3, the terminal voltage V of each of the batteries B1 to B3.
B1 to VB3 are obtained. Next, the start-up control circuit 13 sets the variation range of the difference voltage between the terminal voltages VB1 to VB3 to a voltage range of, for example, 0 (V) to Va (V) (corresponding to a predetermined voltage range in the present invention). , The control signal SC is output to the switching control circuit 12. Specifically, among the voltages VB1 to VB3 between the terminals of the batteries B1 to B3, the highest voltage and the lowest voltage are VMAX and VMI, respectively.
N, and VAM is the charging start voltage corresponding to, for example, 90% of the maximum charge allowable voltage when each of the batteries B1 to B3 is charged to the maximum allowable. In this case, the start-up control circuit 13 determines that the difference voltage between the maximum voltage VMAX and the minimum voltage VMIN exceeds the upper limit voltage Va of the variation width, and that the inter-terminal voltages VB of all the batteries B are equal to or lower than the charge end voltage VAM ( Or less), the control signal SC is output. Therefore, the terminal voltages VB1 to VB1 of the batteries B1 to B3
Even when VB3 is a voltage sufficiently lower than the charge end voltage VAM, if the above condition is not satisfied, the control signal S
Do not output C. This point is different from a general charging device that charges a charging target irrespective of variations in the inter-terminal voltages VB1 to VB3 of the batteries B1 to B3. The upper limit voltage Va of the variation width is set to, for example, a voltage value of about 10% of the maximum chargeable voltage of the batteries B1 to B3.

When the control signal SC is output from the activation control circuit 13, the switching control circuit 12 controls the control signal SC.
The switch S1 is turned on / off by detecting the input of the switch S1 and outputting a switching control signal SS to the switch S1. Thus, the current output from the charging function unit CH or the series circuit of the batteries B1 to B3 is supplied to the winding 2a via the switch S1. Thereafter, the voltage equalizing device 11 performs the above-described voltage equalizing process of the inter-terminal voltage VB.

On the other hand, when at least one of the above conditions is not satisfied, the start control circuit 13 outputs the control signal S
Stop output of C. At this time, the switching control circuit 12 stops the switching control of the switch S1, so that the switching S1 is kept in the off state. As a result, it is possible to prevent a small loss during the voltage equalization processing such as a switching loss of the switch S1 and a loss when the currents I1 to I3 pass through the diode D.

As described above, according to the voltage equalizing apparatus 11, the terminal voltage VB is stored in the battery B having a lower voltage, in the energy of the charging function unit CH, or in the entire series circuit of the batteries B1 to B3. And distributing the energy, the voltage VB between the terminals of all the batteries B is equalized. Therefore, the voltage equalizing process can be performed without the need for the DC power supply PS. Further, when the inter-terminal voltages VB of all the batteries B are equalized, the switching of the switch S1 is stopped, so that a slight loss due to the voltage equalizing process can be prevented. The voltage of the element can be made uniform. Further, each of the batteries B1 to B3
By performing the voltage equalizing process only when any of the terminal voltages VB does not exceed the voltage VAM, it is possible to prevent the battery B from being charged more than necessary. On the other hand, a charging device can also be configured by incorporating the charging function unit CH in the voltage equalizing device 11. In this case, the charging function unit CH performs charging while equalizing the inter-terminal voltage VB of the battery B. Therefore, the most electric energy can be efficiently stored in each battery B.

Next, a voltage equalizing device 21 according to still another embodiment will be described with reference to FIG. Hereinafter, the same components as those of the voltage equalizing devices 1 and 11 are 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. 3, the voltage equalizing device 21
Differs from the voltage equalization devices 1 and 11 in that it includes current transformers CT1 to CT3 (hereinafter, referred to as “current transformer CT” when not distinguished), resistors R1 to R3, and a startup control circuit 23. In this case, the current transformers CT1 to CT3, together with the resistors R1 to R3, constitute a current detecting means in the present invention, detect the current flowing through each diode D, and detect the detection signals SCT1 to SCT3 (hereinafter, when not distinguished, " A detection signal SCT ”). The resistors R1 to R3 are connected to the current transformer CT1.
To CT3, which are connected in parallel to the respective secondary windings and convert the current flowing through the secondary windings into a voltage. Further, the start-up control circuit 23 constitutes a control circuit according to the present invention in cooperation with the switching control circuit 12, and functions as a current supply state determining means for determining a supply state of the current supplied to each battery B. The activation of the switching control circuit 12 is controlled according to the current value of the current supplied to each battery B based on the signals SCT1 to SCT3. Note that in FIG.
The illustration of the same configuration as the voltage equalizing device 11 such as the charging function unit CH and the primary circuit on the winding 2a side is omitted.

In the voltage equalizing device 21, the start control circuit 23 outputs the control signal SC intermittently. As a result, the switching control circuit 12 first switches the switch S1
Is turned on / off once. At this time, when the switch S1 is turned off by the switching control circuit 12, the voltage VO induced on each of the windings 2b to 2d is obtained.
, The currents I1 to I3 are supplied to any one or more batteries B in accordance with the terminal voltage VB of each of the batteries B1 to B3. In this case, the forward current characteristics of the diodes D1 to D3 with respect to the forward voltage are substantially equal, the voltages VB between the terminals of all the batteries B1 to B3 are substantially equal, and in addition, the voltage induced in the windings 2b to 2d. When VO is substantially equal, currents I1 to I3 having substantially the same current value are supplied to all batteries B1 to B3, respectively. On the other hand, when the inter-terminal voltage VB of one of the batteries B is higher than the inter-terminal voltage VB of the other battery B, no current is supplied or the supplied amount is extremely small. At this time, detection signals SCT1 to SCT1 to V3 corresponding to the resistance values of the resistors R1 to R3 and the current values of the currents I1 to I3 flowing through the input windings are applied to the output windings of the current transformers CT1 to CT3.
SCT3 occurs. In this case, since the resistance values of the resistors R1 to R3 are fixed values, the voltage values of the detection signals SCT1 to SCT3 are almost proportional to the current values of the currents I1 to I3. Therefore, the startup control circuit 23 determines the supply state of the currents I1 to I3 to each battery B based on the voltage value of the detection signal SCT.

Specifically, for example, the start-up control circuit 23 determines that the variation width of the difference voltage between the voltage value of the highest voltage detection signal SCT and the voltage value of the other detection signals SCT is within a predetermined range ( For example, the voltage of the highest voltage detection signal SCT is in the range of 0 to 10%, that is, the current I1
It is determined whether or not the maximum current value of I3 is within the range of 0 to 10%. In this case, the start control circuit 2
3, when the voltage value of any of the detection signals SCT is out of the predetermined range, it is determined that the inter-terminal voltage VB of any of the batteries B is not uniform, and the control signal SC is continuously output. By doing so, the switching control circuit 12
, The switching of the switch S1 is continued. The start control circuit 23 detects the terminal voltage VB of each of the batteries B1 to B3 in the same manner as the start control circuit 13 of the voltage equalizing device 11, and detects any terminal voltage VB of each of the batteries B1 to B3. It is preferable to output the control signal SC only when the voltage does not exceed the voltage VAM. On the other hand, when the voltage values of the other detection signals SCT are within the predetermined range, the activation control circuit 23 determines that the inter-terminal voltages VB of all the batteries B are substantially uniform, and switches the output of the control signal SC. Stopping causes the switching control circuit 12 to keep the switch S1 in the off state. Thereafter, the activation control circuit 23 repeats the above processing by intermittently outputting the control signal SC to the switching control circuit 12.

As described above, according to the voltage equalizing device 21, the state of current supply to each battery B is determined and the voltage equalizing process is executed, so that the terminal voltages VB of all the batteries B are substantially uniform. By stopping the switching of the switch S1 when the switching is performed, a slight loss due to the voltage equalization process can be prevented. As a result, the terminal voltages VB1 to VB3 of the batteries B can be equalized with extremely high efficiency in the same manner as the voltage equalizing device 11.

It should be noted that the present invention is not limited to the above-described embodiment of the present invention, but can be appropriately modified. For example, in the embodiment of the present invention, the start-up control circuit 13 and the start control circuit 13 according to the detection results of the voltage detecting means and the current detecting means in the present invention.
Although the example in which the control signal SC outputs or stops the output of the control signal SC has been described, the present invention is not limited to this. For example, by outputting the detection result to the outside of the device, the control device outside the device can control the voltage equalizing device. It is also possible to control the activation and deactivation of the operation as a whole 11 and 21. Further, in the voltage equalizing device 1, the switching control circuit 12
Turns on / off the switch S1 so that the battery B
Although the amount of energy supplied to the battery B is adjusted, the switching control circuit 12 can adjust the amount of energy supplied to the battery B by changing the duty ratio during the ON period of the switch S1. Further, by appropriately changing the turns ratio of each of the windings 2b to 2d, the voltage VB between the terminals of the battery B as a power storage element can be maintained at a different voltage. Furthermore, the storage element in the present invention includes not only a secondary battery but also a capacitor.
The number of storage elements that can be made uniform is not particularly limited,
To equalize the voltage between terminals of many storage elements,
A transformer having a number of output windings corresponding to the number of the storage elements may be used.

[0031]

As described above, according to the voltage equalizing device of the first aspect, one switch means is switched so that when the switching is turned off, the voltage is applied to the electric storage element via the output winding of the transformer and the one-way element. By supplying the energy, the voltage between the terminals of each power storage element can be reliably and extremely easily equalized. Further, the voltage between terminals of the power storage element can be made uniform with high reliability without causing a short circuit accident. In addition, since one switch means, a transformer having approximately the same number of windings as the power storage element, and the same number of unidirectional elements as the power storage element can be used, the number of circuit components can be reduced, and as a result, the device Small size and low cost can be achieved. Further, the voltage detecting means detects the voltage between the terminals of the plurality of power storage elements, thereby controlling the switch means according to the state of the voltage between the terminals or controlling the operation of the entire voltage equalizing apparatus from outside the apparatus. You can also do.

Further, the switching means is caused to start switching based on the detection result of the voltage detecting means when the variation of the voltage between the terminals of the plurality of storage elements is out of a predetermined voltage range, and By stopping switching when is within a predetermined voltage range,
Even a slight loss due to the voltage equalization process can be prevented, and thus the voltage between terminals of the storage element can be equalized with extremely high efficiency.

Further, when the voltage between any one or more terminals of the plurality of power storage elements reaches a predetermined voltage based on the detection result of the voltage detection means, the switching of the switch means is stopped, so that the power storage element can be controlled. Unnecessary charging can be avoided.

According to the voltage equalizing device of the fourth aspect, it is possible to reliably and extremely easily equalize the voltage between the terminals of each storage element in the same manner as the voltage equalizing device of the first aspect. The voltage between terminals of the power storage element can be made uniform with high reliability without causing a short circuit accident, and the size and cost of the device can be reduced. Further, the current detecting means detects each current supplied to the plurality of storage elements, thereby controlling the switch means in accordance with the state of the detected current, or controlling the operation of the entire voltage equalizing apparatus from outside the apparatus. You can also.

Further, based on the detection result of the current detecting means,
By stopping the switching of the switch means when the current supplied to each storage element is within a predetermined range, it is possible to prevent even a slight loss due to the voltage equalization processing, and thereby, the storage efficiency is extremely high. The voltage between the terminals of the element can be made uniform. Further, the control circuit intermittently switches the switch means, so that it is possible to reliably determine whether or not the process of equalizing the voltage between terminals for each storage element is necessary.

In addition, since a DC power supply is constituted by a plurality of power storage elements, voltage equalization processing can be performed without using another DC power supply. As a result, the size of the device can be reduced and the cost can be reduced. On the other hand, by providing a charging function unit that directly charges a plurality of power storage elements connected in series, it is possible to perform charging while equalizing the voltage between the terminals of the power storage elements. It can be stored well in a storage element. Further, since the one-way element is formed by the diode, the control becomes unnecessary and the configuration can be made inexpensively as compared with the case where the FET or the bipolar transistor is used.

[Brief description of the drawings]

FIG. 1 is a basic circuit diagram of a voltage equalizing device 1 for explaining a basic operation principle of the present invention.

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

FIG. 3 is a circuit diagram of a part of a voltage equalizing device 21 according to still another embodiment of the present invention.

FIG. 4 is a circuit diagram of a conventional voltage equalizing device 31.

[Explanation of symbols]

 1,11,21 Voltage equalizer 2 Transformer 2a-2d winding 12 Switching control circuit 13,23 Start-up control circuit B1-B3 Battery CT1-CT3 Current transformer CH Charging function unit D1-D3 Diode R1-R3 Resistance S1 switch VB1 To VB3 terminal voltage

Claims (9)

[Claims] 1. A voltage equalizing device for supplying energy to each of a plurality of power storage elements connected in series to equalize voltages between terminals of the power storage elements to voltages substantially equal to each other. Having a plurality of input windings and a plurality of output windings wound with substantially the same number of turns,
Switch means connected in series to the input winding; and a plurality of unidirectional elements connected between the output windings and the power storage elements, respectively, for supplying the storage energy of the transformer to the power storage elements. And a voltage detecting means for detecting the inter-terminal voltage of each of the plurality of power storage elements connected in series. 2. The switching means starts switching when a variation in the voltage between the terminals of the plurality of power storage elements is out of a predetermined voltage range based on a detection result of the voltage detecting means, and 2. The voltage equalizing device according to claim 1, wherein the switching is stopped when the variation of the inter-voltage is within the predetermined voltage range. 3. The method according to claim 1, wherein the switch is configured to output one of the plurality of storage elements based on a detection result of the voltage detector.
When one or more of the inter-terminal voltages reaches a predetermined voltage set based on the maximum chargeable voltage of the power storage element,
3. The voltage equalizing device according to claim 1, wherein the switching is stopped. 4. A voltage equalizing device for supplying energy to each of a plurality of power storage elements connected in series to equalize voltages between terminals of the power storage elements to voltages substantially equal to each other. Having a plurality of input windings and a plurality of output windings wound with substantially the same number of turns,
Switch means connected in series to the input winding of the transformer and each of the output windings of the transformer and each of the power storage elements are connected to enable the storage energy of the transformer to be supplied to the power storage element. A voltage equalizing device comprising: a plurality of one-way elements; and current detecting means for detecting a current supplied to each of the power storage elements via each of the one-way elements. 5. The switching device according to claim 1, wherein the switching is stopped when a variation in the current supplied to each of the power storage elements is within a predetermined range based on a detection result of the current detecting device. Item 5. A voltage equalizing device according to Item 4. 6. The switch means is intermittently switched, and when the variation is determined to be within the predetermined range based on a detection result of the current detecting means, the switch means is controlled to an off state, and 6. The voltage equalizing device according to claim 5, further comprising a control circuit that continues switching to the switch means when it is determined that the voltage is out of the range. 7. The power supply according to claim 1, wherein the DC power supply includes the plurality of power storage elements.
The voltage equalizing device according to any one of the above. 8. The voltage equalizing device according to claim 1, further comprising a charging function unit that directly charges the plurality of power storage elements connected in series. 9. The voltage equalizing device according to claim 1, wherein the one-way element is formed of a diode.