CN106026285B

CN106026285B - Battery equalizer composed of multi-winding transformer

Info

Publication number: CN106026285B
Application number: CN201610550348.7A
Authority: CN
Inventors: 肖兴龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-07-06
Filing date: 2016-07-06
Publication date: 2024-02-06
Anticipated expiration: 2036-07-06
Also published as: CN106026285A

Abstract

The battery equalizer composed of the multi-winding transformer is characterized in that: the magnetic core is provided with a plurality of windings with the same number of turns and different winding directions, each winding is connected in series with the switch tube to form a single-tube forward circuit or a complementary push-pull circuit, and the single-tube forward circuit or the complementary push-pull circuit is connected with the positive electrode and the negative electrode of each battery in parallel, as shown in figure 1. Dividing switching tubes in a corresponding single-tube forward circuit into a group A switching tube and a group B switching tube according to two winding directions of windings, wherein the group A switching tube and the group B switching tube are alternately switched on and off when the circuit works, the interval time is equal, and the switching frequency adopts high frequency; by utilizing the working characteristic that the single-tube forward circuit and the complementary push-pull circuit are combined together, the natural magnetic reset of the magnetic core is realized, and the voltage balance of the whole battery pack is realized. In order to improve the equalization ability and accommodate a greater number of battery equalization, further measures are taken: all single-tube forward circuits are changed into complementary push-pull circuits; a plurality of transformers are used, secondary windings are added on the magnetic cores of the transformers, and all the secondary windings are connected in parallel according to the principle that the same-name ends are connected in parallel.

Description

Battery equalizer composed of multi-winding transformer

Technical Field

The patent relates to the field of batteries, in particular to a battery equalizer consisting of a multi-winding transformer.

Background

The battery pack can work normally and fully exert the efficacy, the battery equalizer is needed, the development of the battery equalizer is very slow although the lithium battery appears for many years, and the number of the equalizer which can be used in the market is small at present. It is a common wish and effort goal to obtain a cost effective voltage equalizer.

The simplest approach is to make a voltage equalizer with multiple windings around one core, and although many have made such attempts, no meaningful results have been achieved because the magnetic reset circuit does not give the correct processing, so that there are two results obtained: 1, the magnetic core cannot be reset, so that an actual machine cannot be made; 2, a special magnetic reset circuit must be added, and as a result, the volume and cost of the circuit are increased, and the conversion efficiency is reduced.

Disclosure of Invention

The technical problems to be solved are as follows:

and the multi-winding transformer magnetic core in the battery equalizer can be reasonably reset, all the batteries in the battery pack can be balanced and stabilized, and meanwhile, the circuit structure is simple, and the cost is low.

The solution is as follows:

in order to solve the magnetic reset problem without adding a special magnetic reset circuit, the equalizer adopts a method of winding a plurality of coil windings with the same number of turns and different winding directions on one magnetic core, and forms a single-tube forward circuit or a complementary push-pull circuit by connecting with a switch tube in series and is connected with the positive electrode and the negative electrode of each battery in parallel, as shown in figure 1. By utilizing the working characteristic that the complementary push-pull circuit and the single-tube forward circuit are combined together, the automatic magnetic reset of the magnetic core can be realized, a special magnetic reset circuit is not needed any more, and the voltage balance of the whole battery pack can be realized. The specific scheme is as follows:

scheme 1 the equalizer uses a multi-winding transformer with the same number of turns for each winding and different winding directions, as shown in fig. 1. A single-tube forward circuit or a complementary push-pull circuit is connected between the positive electrode and the negative electrode of each battery. According to different winding directions of the windings, a single-tube forward circuit corresponding to one winding direction is called an A circuit, a corresponding switching tube is called an A switching tube, and a corresponding battery is called an A group battery; the single-tube forward circuit corresponding to the other winding direction is called a B circuit, the corresponding switching tube is called a B switching tube, and the corresponding battery is called a B group battery. When the equalizer works, all the switch tubes A and all the switch tubes B are alternately switched on and off, the interval time is equal, and the switching frequency is high frequency. Since the windings of the switch tubes a and B are opposite in winding direction, their alternate conduction necessarily results in natural magnetic reset of the transformer core.

Because of the existence of the complementary push-pull circuit, the bridge battery is actually composed of two single-tube forward circuits A and B, and the corresponding batteries belong to the group A battery and the group B battery, and are also called bridge batteries. When equalization is stable, all the A-group batteries achieve the voltage completely consistent, and all the B-group batteries achieve the voltage completely consistent, because the bridge batteries are arranged in the A-group batteries and the B-group batteries, all the batteries take the bridge batteries as the reference, and finally all the voltages are consistent, so that the purpose of equalization is achieved.

And in the scheme 2, all single-tube forward circuits are changed into complementary push-pull circuits on the basis of the scheme 1, so that the equalization capability is doubled and improved.

In the scheme 3, when a transformer is used for winding a plurality of windings with a required number, a secondary winding is added to the transformer based on the scheme 1, and a plurality of identical transformers are used, so that the secondary windings of all the transformers are all connected in parallel according to the principle that the same-name ends are connected in parallel.

In the scheme 4, in order to further improve the equalization effect, all single-tube forward circuits in the circuit in the scheme 3 are changed into complementary push-pull circuits, so that the equalization capability is doubled.

The invention has the beneficial effects that:

this patent has solved the magnetic reset problem of multi-winding transformer in voltage equalizer, not only does not increase special magnetic reset circuit, can ensure moreover that the voltage of all batteries reaches the complete unanimity after the group battery reaches equilibrium stability.

The circuit is simple, the manufacturing cost is low, and the voltage equalizer with excellent cost performance really goes to practical use.

Drawings

FIG. 1 is a circuit diagram of a single transformer equalizer consisting of a mixture of single-tube forward and complementary push-pull circuits

FIG. 2 is a circuit diagram of a single transformer equalizer consisting of complementary push-pull circuits

Fig. 3, a circuit diagram of a multi-transformer equalizer consisting of a mixture of single-tube forward and complementary push-pull circuits

FIG. 4 is a circuit diagram of a multi-transformer equalizer consisting of complementary push-pull circuits

Detailed Description

Embodiment 1, single-transformer equalizer consisting of a mixture of a single-tube forward circuit and a complementary push-pull circuit

As shown in fig. 1, each winding turn of the transformer T is all the same, i.e., n1=n2=1n3=2n3=n4=n5=.=. All switching tubes Q1, Q2, 1Q3, 2Q3, Q4, Q5.. Qn can be MOS tubes, IGBT, etc.

As can be seen from the figure, the complementary push-pull circuit is composed of two single-tube forward circuits, and the winding directions of the windings corresponding to the two single-tube forward circuits are opposite.

Classifying all corresponding switching tubes into two groups according to two winding directions of the transformer winding: a group A switching tube and a group B switching tube. The group A switching tubes are Q1, 1Q3, Q5 and Q7. The group B switching tubes are Q2, 2Q3, Q4, Q6, Q8.. The switch tubes of the group A are simultaneously turned on and off, and the switch tubes of the group B are simultaneously turned on and off.

When the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time is equal to the switching-off time; the switching frequency is high frequency, so that the voltage of a single battery can be coupled to the corresponding windings of other batteries in an equal proportion after the voltage is applied to the windings of the transformer through the switching tube, and excellent balancing effect is ensured.

The driving pulse of the switch tube of the group A is DrA, the driving pulse of the switch tube of the group B is DrB, the DrA and the DrB are compared, the voltage waveforms are the same, the duty cycle is 50%, and the phase difference is 180 degrees.

When DrA is high, drB is low, the group a switching transistors Q1, 1Q3, Q5, Q7 are turned on, the group B switching transistors Q2, 2Q3, Q4, Q6, Q8. are turned off, the voltage of B1 is applied to the N1 winding, the voltage of B3 is applied to the 1N3 winding, the voltage of B5 is applied to the N5 winding, and the voltage of B7 is applied to the N7 winding. At the same time, the core of the transformer T starts to magnetize.

When DrB is at high level, drA is at low level, group B switching transistors Q2, 2Q3, Q4, Q6, Q8. are turned on, group a switching transistors Q1, 1Q3, Q5, Q7 are turned off, voltage of B2 is applied to winding N2, voltage of B3 is applied to winding 2N3, voltage of B4 is applied to winding N4, voltage of B6 is applied to winding N6. The equalization effect is equivalent to that produced by mechanically disconnecting the cells from the stack and then all in parallel. At the same time, the core of the transformer T starts to reset.

When DrA is high and DrB is low, the circuit begins another cycle.

When equalization has stabilized, B1, B3, B5, B7. in group a cells, cells reach full voltage agreement, i.e., b1=b3=b5=b7=; b2, B3, B4, B6. in the B group of cells reach a completely uniform voltage, i.e. b2=b3=b4=b6=.because there are B3 cells in both the a and B groups of cells, the voltage of each cell in the whole group of cells eventually reaches a completely uniform voltage with B3 as reference, so the B3 cell is also referred to as bridge cell, and the corresponding complementary push-pull circuit is also referred to as transit circuit.

The above analysis assumes that the 3 rd string of cells is a bridge cell, and if the bridge cell is any of the B1, B2, B3..bn cells, the same is true; more than one bridge battery can be arranged in the whole battery pack, so that more than one transfer circuit is arranged; the more bridge cells, the easier it is to achieve complete voltage equalization of the battery pack.

In fig. 1, it is assumed that the winding directions of the transformer windings are consistent from small to large according to the battery sequence, and if the winding directions are not consistent, the winding directions of the windings are randomly distributed from small to large according to the battery sequence, so that the analysis conclusion is also true.

Embodiment 2 Single-transformer equalizer consisting of complementary push-pull circuits

In order to further improve the equalizing ability, the single-tube forward circuit in fig. 1 is all changed to a complementary push-pull circuit, the equalizing ability is doubled, and as shown in fig. 2, the number of turns of all windings in the drawing is all the same, i.e., 1n1=1n2=2n1=2n2=3n1= 3n2=4n1=. All the switching tubes 1Q1, 1Q2, 2Q1, 2Q2, 3Q1, 3Q2.

Classifying according to two winding directions of a transformer winding, and dividing switching tubes connected with the winding in series into two groups: a group A switching tube and a group B switching tube. Group A switching tubes Q1, 2Q1, 3Q1 nQ1 is turned on and off simultaneously; the group B switching transistors Q2, 2Q2, 3Q2, 4Q2.

When DrA is high, drB is low, group a switching tubes 1Q1, 2Q1, 3Q1, 4Q1 are turned on, group B switching tubes 1Q2, 2Q2, 3Q2, 4Q2 are turned off, voltage of B1 is applied to 1N1 winding, voltage of B2 is applied to 2N1 winding, voltage of B3 is applied to 3N1 winding, voltage of Bn is applied to nN1 winding, so that B1, B2, B3. At the same time, the core of the transformer T starts to magnetize.

When DrB is at a high level, drA is at a low level, the group B switching tubes 1Q2, 2Q2, 3Q2, 4Q2 are turned on, the group a switching tubes 1Q1, 2Q1, 3Q1, 4Q1 are turned off, the voltage of B1 is applied to the 1N2 winding, the voltage of B2 is applied to the 2N2 winding, the voltage of B3 is applied to the 3N2 winding, the voltage of Bn is applied to the nN2 winding, and thus the B1, B2, B3, B4.. The equalization effect is equivalent to that produced by mechanically disconnecting the B1, B2, B3, B4.. Bn cells from the stack and then all being connected in parallel. At the same time, the core of the transformer T starts to reset.

When DrA is high, drB is low, the circuit starts another cycle.

When equalization is stabilized, the cells in the stack all reach voltage uniformity. The circuit is characterized in that: all cells are connected in parallel in an electrically isolated manner for equalization throughout the time range.

Embodiment 3a multiple transformer equalizer consisting of a mixture of single-tube forward and complementary push-pull circuits

For the case of a relatively large number of series batteries, a required number of coils are not wound on one magnetic core, in order to solve the problem, as shown in fig. 3, the equalizer uses a plurality of identical transformers, the total number of the transformers is m, each transformer is added with a secondary winding Ns with the same number of turns on the basis of the transformer used in the embodiment 1, and the secondary windings Ns of all the transformers are all connected in parallel according to the principle of parallel connection of the same name ends; the specific circuit structure is as follows: the battery pack comprises m identical battery packs G1, G2 and Gj. Gj (Gj is the j-th battery pack in the battery packs), wherein each battery pack is formed by serially connecting n batteries in sequence, and both ends of the positive electrode and the negative electrode of each battery are connected with a capacitor in parallel; m identical multi-winding transformers T1, T2, & gt Tj., & Tm (Tj being the j-th one of the transformers) are directly responsible for voltage equalization of the battery packs G1, G2, & gt Gj. & gt Gm, respectively, namely, T1 is directly responsible for the voltage equalization of G1, T2 is directly responsible for the voltage equalization of G2, and Tj is directly responsible for the voltage equalization of Gj; the construction characteristics of each transformer are as follows: is composed of at least n+1 primary coils with identical turns and a secondary coil with Ns turns. All the switching tubes can be MOS tubes, IGBT and the like.

The operation principle of the circuit is basically the same as that of embodiment 1 described above, except that: the voltage balance of the whole battery pack is realized through the coupling of secondary coils which are connected in parallel among the battery packs corresponding to different transformers, G1, G2 and Gj.; 1B1, 1B2,1B 3..1bn in fig. 3 is group 1 battery group G1, sharing transformer T1;2B1, 2B2,2B 3..2bn is group 2 battery group G2, sharing transformer T2; .. jB1, jB2, jB3. jBn is the j-th battery group Gj, sharing a transformer Tj; .. mB1, mB2, mB3. mBn are the m-th battery group Gm, sharing a transformer Tm. According to the winding direction of the transformer winding in the whole equalizer, all the switching tubes are divided into A groups and B groups, wherein the A groups of switching tubes are as follows: 1Q1, 1Q3A, 1Q5, 1Q 7..2Q 1, 2Q3A, 2Q5, 2Q 7..mq 1, mQ3A, mQ5, mQ 7..; the switch tube of the group B is as follows: 1Q2, 1Q3B, 1Q4, 1Q 6..2Q 2, 2Q3B, 2Q4, 2Q 6..mq 2, mQ3B, mQ4, mQ 6..; the winding directions of the windings corresponding to the switch tubes of the group A and the switch tubes of the group B are opposite. The group a switching transistors are simultaneously turned on and off, the corresponding driving pulse is referred to as 1DR1, and the corresponding batteries 1B1, 1B3,1B 5, 1B 7..2B 1, 2B3,2B 5, 2B 7..mb 1, mB3, mB5, mB 7..are referred to as group a batteries; the group B switching transistors are simultaneously turned on and off, the corresponding driving pulse is called 1DR2, a corresponding battery 1B2,1B3,1B4,1B6. 2B2,2B3,2B4,2B6. MB2, mB3, mB4, mB 6..is referred to as a B group battery; when the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time and the switching-off time are equal; compared with 1DR1 and 1DR2, the voltage waveforms are identical, the duty cycles are 50%, and the phases are 180 degrees different; the switching frequency is high frequency to ensure excellent equalization.

When 1DR1 is at a high level, 1DR2 is at a low level, the group a switching tube is turned on, the group B switching tube is turned off, the voltage of the battery 1B1 is applied to the 1N1 winding, the voltage of the 1B3 is applied to the 1N3A winding, the voltage of the 1B5 is applied to the 1N5 winding, the voltage of the 1B7 is applied to the 1N7 winding..2B 1 is applied to the 2N1 winding, the voltage of the 2B3 is applied to the 2N3A winding, the voltage of the 2B5 is applied to the 2N5 winding, the voltage of the 2B7 is applied to the 2N7 winding..mb 1 is applied to the mN1 winding, the voltage of the mB3 is applied to the mN5 winding..; the equalization effect is equivalent to that produced by mechanically totally disassembling the a-group cells and then totally paralleling them together. At the same time as the time of this, the cores of transformers T1, T2, T3, T4.

When 1DR2 is at a high level, the group B switching tube is turned on, the group a switching tube is turned off, the voltage of 1B2 is applied to the 1N2 winding, the voltage of 1B3 is applied to the 1N3B winding, the voltage of 1B4 is applied to the 1N4 winding, the voltage of 1B6 is applied to the 1N6 winding..2b2 is applied to the 2N2 winding, the voltage of 2B3 is applied to the 2N3B winding, the voltage of 2B4 is applied to the 2N4 winding, the voltage of 2B6 is applied to the 2N6 winding..mb 2 is applied to the mN2 winding, the voltage of mB3 is applied to the mN3B winding, the voltage of mB4 is applied to the mN4 winding..; the equalization effect is equivalent to that produced by mechanically totally disassembling the B-group cells and then totally paralleling them together. At the same time as the time of this, the cores of transformers T1, T2, T3, T4.

When 1DR1 is high, 1DR2 is low, and the circuit begins another cycle.

When the balance is stabilized, each battery in the group A battery reaches the voltage completely consistent; each cell of group B cells the voltage is completely consistent; since both sets of a and B have 1B3, 2B3, 3B 3..mb3 cells, the voltage of each cell in the entire set of cells is eventually made to be all uniform with reference to 1B3, 2B3, 3B 3..mb3, so that the 1B3, 2B3, 3B 3..mb3 cells are also referred to as bridge cells, and the corresponding complementary push-pull circuits are also referred to as transit circuits.

The above analysis assumes that the 1B3, 2B3, 3B3. MB3 battery is a bridge battery, if the bridge battery is any of the other string of batteries in the battery pack, i.e. 1B1, 1B2,1B 3. 1Bn, any one of 2B1, 2B2,2B 3..2bn, the same holds true for any one of 3B1, 3B2, 3B 3..3 bn..any one of mB1, mB2, mB3.. mBn; more than one bridge battery can be arranged in the battery group corresponding to each transformer, so that more than one transfer circuit is arranged; the more bridge cells, the easier it is to achieve complete voltage equalization across the battery pack.

The above analysis assumes that the same name ends of the windings are equally spaced according to the cell ordering, the conclusion is also true if the winding direction homonymous ends of the windings are randomly distributed.

Embodiment 4 Multi-transformer equalizer consisting of complementary push-pull circuits

In order to further improve the equalization capability, all single-tube forward circuits in fig. 3 are changed into complementary push-pull circuits, and as shown in fig. 4, all winding turns with center taps are identical; each transformer is provided with a secondary coil Ns with the same number of turns, and all the secondary coils Ns are connected in parallel according to the principle that the same-name ends are connected in parallel; all the switching tubes can be MOS tubes, IGBT and the like.

The operation principle of the circuit is basically the same as that of embodiment 2 described above, except that: and the voltage balance of the whole battery pack is realized through the secondary coils which are connected in parallel.

Depending on the direction of winding of the winding, all the switching tubes are divided into a group A and a group B, wherein the switching tubes in the group A are as follows: 1Q1A, 1Q2A, 1Q3A, 1Q4 a..2Q 1A, 2Q2A, 2Q3A, 2Q4 a..3Q 1A, 3Q2A, 3Q3A, 3Q4 a..mq 1A, mQ2A, mQ a, mQ4 a..; the switch tube of the group B is as follows: 1Q1B, 1Q2B, 1Q3B, 1Q4 b..2Q 1B, 2Q2B, 2Q3B, 2Q4 b..3Q 1B, 3Q2B, 3Q3B, 3Q4 b..mq 1B, mQ2B, mQ B, mQ4 b..; the winding directions of the windings corresponding to the switch tubes of the group A and the switch tubes of the group B are opposite. The group A switching tubes are simultaneously turned on and off, and corresponding driving pulses are called 1DR1; the switch tubes of the group B are simultaneously turned on and off, and corresponding driving pulses are called 1DR2; when the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time and the switching-off time are equal; 1DR1 and 1DR2 are identical in voltage waveform, and have duty cycles of 50% and 180 degrees out of phase.

When 1DR1 is at a high level, 1DR2 is at a low level, the group a switching tube is turned on, the group B switching tube is turned off, the voltage of the battery 1B1 is applied to the 1N1A winding, the voltage of the battery 1B2 is applied to the 1N2A winding, the voltage of the battery 1B3 is applied to the 1N3A winding, the voltage of the battery 1B4 is applied to the 1N4A winding, the voltage of the battery 2B2 is applied to the 2N2A winding, the voltage of the battery 2B3 is applied to the 2N3A winding, the voltage of the battery 2B4 is applied to the 2N4A winding, the voltage of the battery 3B1 is applied to the 3N3A winding, the voltage of the battery 3B4 is applied to the 3N4A winding, the voltage of the battery mB1 is applied to the 1A winding, the voltage of the battery mB2 is applied to the 2A winding, the voltage of the battery 2B2 is applied to the voltage of the battery 2B4 is applied to the 2N3A winding, the voltage of the battery B4 is applied to the battery 2B4, and the voltage of the battery 2B4 is applied to the 3A winding, the voltage of the battery is applied to the voltage of the battery 2B4, and the voltage of the battery is applied to the battery 2B4 is applied to the voltage of the battery 2B 4A voltage of the battery 2A voltage of the battery, and the battery is all 2 is parallel and 3, and the voltage of the battery is applied to the voltage 1 is parallel and 3 voltage of the battery, and 3 voltage of the battery is applied to the voltage 1; the equalization effect is equivalent to that produced by mechanically totally disassembling all cells and then totally paralleling them together. At the same time as the time of this, the cores of transformers T1, T2, T3.

When 1DR2 is at a high level, the group B switching tube is turned on, the group a switching tube is turned off, the voltage of the battery 1B1 is applied to the 1N1B winding, the voltage of the 1B2 is applied to the 1N2B winding, the voltage of the 1B3 is applied to the 1N3B winding, the voltage of the 1B4 is applied to the 1N4B winding..the voltage of the battery 2B1 is applied to the 2N1B winding, the voltage of the 2B2 is applied to the 2N2B winding, the voltage of the 2B3 is applied to the 2N3B winding..the voltage of the battery mB1 is applied to the mN1B winding, the voltage of the mB2 is applied to the mN2B winding, the voltage of the mB3 is applied to the mN3B winding, the voltage of the mB4 is applied to the mN4B winding.. mBn is applied to the mnb winding; in this way, through transformer coupling, 1B1, 1B2,1B 3..2B 1, 2B2,2B 3..mB 1, mB2, mB3.. mBn batteries are connected in parallel in a voltage isolation mode, so that the high-voltage batteries can transmit energy to the low-voltage batteries, and the voltages of all the batteries tend to be uniform; the equalization effect is equivalent to that produced by mechanically disconnecting all cells from the stack and then all being connected in parallel. At the same time, the cores of transformers T1, T2, T3.

When 1DR1 is high, 1DR2 is low, and the circuit begins another cycle.

When equalization has reached stability, all cells in the entire stack reach full voltage uniformity. The circuit is characterized in that: all batteries are connected in parallel in an electrical isolation way all the time within the whole time range for balancing, and the balancing effect is good.

The patent is suitable for lithium batteries and lead-acid batteries, or battery packs with the same specification are connected in series, and the number of the series connection of the batteries (or the battery packs with the same specification) is not limited.

The above embodiments are only for illustrating the present patent, not for limiting the present patent, and various changes and combinations can be made by one skilled in the relevant art without departing from the spirit and scope of the present patent, so that all equivalent technical solutions also belong to the scope of the present patent, and the protection scope of the present patent should be listed in the claims.

Claims

1. The battery equalizer composed of the multi-winding transformer comprises the following circuit components: n batteries B1, B2 and Bn are sequentially connected in series, and the positive and negative ends of each battery are connected with a capacitor in parallel; the number of turns of each winding on the magnetic core of the transformer is completely the same, the total number of the windings is at least n+1, the windings are distributed in the positive and negative winding directions, each winding is connected in series with a switching tube to form a single-tube forward circuit, and the single-tube forward circuit is connected in parallel with the positive and negative ends of corresponding batteries in the series battery pack; the battery pack is provided with at least one string of batteries, two single-tube forward circuits are connected at the two ends of the positive electrode and the negative electrode of the battery pack in parallel, the winding directions of windings in the two single-tube forward circuits are opposite, and the two single-tube forward circuits are combined together to be also called a complementary push-pull circuit; dividing corresponding switching tubes in a single-tube forward circuit and a complementary push-pull circuit into two groups of switching tubes A and B according to two winding directions of a transformer winding; the winding directions of the windings corresponding to the switch tubes of the group A are the same, and the winding directions of the windings corresponding to the switch tubes of the group B are the same; the winding directions of the windings corresponding to the switch tubes of the group A and the switch tubes of the group B are opposite; when the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time and the switching-off time are equal; the switching frequency is high frequency, so that the battery voltage can be coupled to the corresponding windings of other batteries in an equal proportion after being conducted through a switching tube and added to the windings of the transformer, and excellent balancing effect is ensured; after the balance is stabilized, the voltages of all batteries are consistent with the voltages of the batteries corresponding to the complementary push-pull circuits as reference, the purpose of equalization is achieved.

2. A battery equalizer consisting of a multi-winding transformer, the circuit comprises the following components: n batteries B1, B2 and Bn are sequentially connected in series, and the positive and negative ends of each battery are connected with a capacitor in parallel; the transformer comprises a multi-winding transformer, wherein a plurality of windings with center taps are arranged on a magnetic core of the transformer, the number of turns of each winding is the same, and the number of windings with the center taps is n; two ends of each winding with a center tap are respectively connected with a switching tube to form a complementary push-pull circuit which is connected in parallel with the corresponding battery anode and cathode ends in the series battery pack; dividing the corresponding switching tubes into two groups of switching tubes A and B according to the winding direction of the corresponding windings of the complementary push-pull circuit; the winding directions of the windings corresponding to the switch tubes of the group A are the same, and the winding directions of the windings corresponding to the switch tubes of the group B are the same; the winding directions of the windings corresponding to the switch tubes of the group A and the switch tubes of the group B are opposite; when the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time and the switching-off time are equal; the switching frequency is high frequency, so that the battery voltage can be coupled to the corresponding windings of other batteries in an equal proportion after being switched on by a switching tube and added to the windings of the transformer, and excellent balancing effect is ensured; after the equalization is stabilized, the voltages of all the batteries are completely consistent, and the purpose of equalization is achieved.

3. The battery equalizer composed of the multi-winding transformer comprises the following circuit components: m identical battery groups G1 g2,.. Gj...gm, each battery pack is formed by serially connecting n batteries, the positive and negative ends of each battery are connected in parallel with a capacitor; m identical multi-winding transformers T1T 2 Tj. Tm, are respectively and directly responsible for the battery packs G1, G2 voltage equalization of Gj..gm; the constitution of each transformer is: the winding structure consists of a plurality of primary windings and a secondary winding, wherein the number of the primary windings is at least n+1, and the primary windings are distributed in the positive and negative winding directions; the secondary coils of all transformers are all connected in parallel according to the principle that the same-name ends are connected in parallel, and the voltage balance among the battery packs G1 and G2 and the battery packs Gj. Gm is realized through the mutual coupling of the secondary coils and the primary coils of all the transformers connected in parallel, so that the voltage balance of the whole battery pack is realized; the implementation method of the single transformer Tj directly responsible for voltage equalization of the battery pack Gj is as follows: one end of each primary winding in the transformer Tj is connected in series with a switching tube to form a single-tube forward circuit which is connected in parallel with the positive and negative ends of corresponding batteries in the Gj battery pack, wherein at least one string of batteries is arranged in the Gj battery pack, the positive and negative ends of the Gj battery pack are connected in parallel with two single-tube forward circuits, winding directions of windings in the two single-tube forward circuits are opposite, so that a complementary push-pull circuit is formed, the string of batteries are also called bridge batteries, and at least one bridge battery exists in the Gj battery pack; dividing corresponding switching tubes in all single-tube forward circuits and complementary push-pull circuits into two groups of switching tubes A and B according to two winding directions of primary windings of all transformers; the winding directions of the windings corresponding to the switch tubes of the group A are the same, and the winding directions of the windings corresponding to the switch tubes of the group B are the same; the winding directions of the windings corresponding to the switch tubes of the group A and the switch tubes of the group B are opposite; when the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time and the switching-off time are equal; the switching frequency is high frequency, so that the battery voltage can be coupled to the corresponding windings of other batteries in an equal proportion after being conducted through a switching tube and added to the windings of the transformer, and excellent balancing effect is ensured; after equalization is stabilized, the voltages of all batteries are consistent with each other by taking the battery voltage corresponding to the complementary push-pull circuit as a reference, so that the purpose of equalization is realized.

4. The battery equalizer composed of the multi-winding transformer comprises the following circuit components: m identical battery groups G1 g2,.. Gj...gm, each battery pack is formed by serially connecting n batteries, the positive and negative ends of each battery are connected in parallel with a capacitor; m identical multi-winding transformers T1T 2 Tj. Tm, are respectively and directly responsible for the battery packs G1, G2 voltage equalization of Gj..gm; the constitution of each transformer is: the winding comprises a plurality of primary windings and a secondary winding, wherein all the primary windings are windings with center taps, the number of turns is identical, and the windings are distributed in the positive and negative winding directions; the number of windings with the center tap in each transformer is n; the secondary coils of all transformers are all connected in parallel according to the principle that the same-name ends are connected in parallel, and the voltage balance among the battery packs G1 and G2 and the battery packs Gj. Gm is realized through the mutual coupling of the secondary coils and the primary coils of all the transformers connected in parallel, so that the voltage balance of the whole battery pack is realized; the implementation method of the single transformer Tj directly responsible for voltage equalization of the battery pack Gj is as follows: two ends of each winding with a center tap in the transformer Tj are respectively connected with a switching tube in series to form a complementary push-pull circuit which is connected in parallel with the positive and negative ends of the corresponding battery in the Gj battery pack; dividing the corresponding switching tubes into two groups of switching tubes A and B according to two winding directions of windings with center taps in all transformers; the winding directions of the windings corresponding to the switch tubes of the group A are the same, and the winding directions of the windings corresponding to the switch tubes of the group B are the same; the winding directions of the windings corresponding to the switch tubes of the group A and the switch tubes of the group B are opposite; when the equalizer works, the switch tubes of the group A and the switch tubes of the group B are alternately switched on and off, and the switching-on time and the switching-off time are equal; the switching frequency is high frequency, so that the battery voltage can be coupled to the corresponding windings of other batteries in an equal proportion after being conducted through a switching tube and added to the windings of the transformer, and excellent balancing effect is ensured; after the equalization is stabilized, the voltages of all the batteries are all consistent, the purpose of equalization is achieved.