CN111183545A

CN111183545A - Battery pack balancing method and device and battery pack

Info

Publication number: CN111183545A
Application number: CN201780092927.4A
Authority: CN
Inventors: 王创社
Original assignee: Shenzhen Qiangneng Electric Co ltd
Current assignee: Shenzhen Qiangneng Electric Co ltd
Priority date: 2017-07-19
Filing date: 2017-07-19
Publication date: 2020-05-19
Also published as: WO2019014864A1

Abstract

The invention discloses a battery pack equalization method, a device and a battery pack, wherein the battery comprises various chemical batteries, photovoltaic batteries, capacitors, super capacitors, fuel cells and the like and/or combinations thereof, and the method mainly comprises the following steps: determining different groups of same-potential points in the battery pack; and connecting part or all of the same-potential points in at least one same-potential point group through a current regulation unit. According to the battery pack balancing method and device, the battery pack and the product comprising the battery pack, the voltage balancing problem, the current balancing problem and the capacity balancing problem of the battery pack can be solved.

Description

Battery pack balancing method and device and battery pack

Technical Field

The present invention relates to battery equalization technologies, and in particular, to a battery equalization method and apparatus, and a battery.

Background

When the batteries and the capacitors are connected in series and in parallel to form a group, the performance is reduced after the group is formed and the service life is shortened due to the inconsistency of the single devices; when the photovoltaic battery packs are assembled into a module, because of the inconsistency, shielding and other factors of the single photovoltaic battery, mismatching can be generated, the power generation amount of a photovoltaic system is reduced, and system faults are increased; when a plurality of fuel cells are connected in series and in parallel to form a group, the performance of the whole electric pile can be influenced or even the electric pile is invalid due to the inconsistency of the single fuel cells.

The prior art solves the problem of voltage equalization of series batteries by a passive equalization method and an active equalization method. The passive equalization realizes voltage equalization by using the energy of a high-voltage battery consumed by a resistor, and although the circuit is simple and reliable and has low cost, the equalization current is small, the energy loss is large, and heat is generated. Active equalization is realized by adopting an energy transfer mode, generally, the energy of a high-voltage battery in a series battery pack is transferred to other batteries to reduce the voltage of the high-voltage battery, namely, the high-voltage battery is used for supplementing the energy of a low-voltage battery; although the balance current is large and the energy loss is small, the circuit is complex, the cost is high and the reliability is relatively low.

In addition, the problem of current balance of the parallel batteries is solved, and no mature scheme exists in the prior art. Generally, only batteries with good consistency can be accurately detected and screened to be connected in parallel. However, this increases the cost of batteries for grouping and does not ensure the current uniformity of the batteries connected in parallel, because the batteries are installed at different positions when connected in parallel, and the performance of the batteries is differentiated as the batteries are used, resulting in more inconsistent current.

Although the working current of each battery can be obviously balanced when the batteries are grouped, the problem of voltage balance of the batteries connected in series is solved in each string, and the system is too complex, high in cost and low in reliability no matter the passive balancing method or the active balancing method is adopted. Therefore, when the batteries are grouped at present, the mode of firstly connecting in parallel and then connecting in series is mostly adopted, and the voltage balance problem is simplified. For the current balance of the parallel batteries, the batteries with good consistency are accurately detected to be connected in parallel when the batteries are assembled, namely the batteries are ensured by the batteries.

The problem of mismatch of solar cells is solved, and the existing scheme adopts a high-quality photovoltaic device to avoid shadow and shielding as much as possible; or maximum power tracking (MPPT) for each string of cell assemblies. But the cost is increased, the problem of inconsistent shadow shielding and attenuation of the photovoltaic device cannot be avoided, the failure rate is high, and the phenomenon of double peaks or multiple peaks of power cannot be avoided. The problem of fuel cell is in groups is solved, generally through carrying out accurate detection and screening to the device, select for use the device that the uniformity is good to come into groups, but can increase the cost that the device is in groups, can't guarantee in addition that device performance differentiation produces the nonconformity in the use, causes whole group's performance to descend.

Therefore, a battery pack balancing method and device are needed to solve the problems of voltage balancing, current balancing and capacity balancing of the battery pack.

Disclosure of Invention

The invention provides a battery pack balancing method, a device and a battery pack, aiming at the defects in the prior art, and solves the problem of inconsistency when batteries are grouped and applied, wherein the batteries comprise various chemical batteries, photovoltaic batteries, capacitors, super capacitors, fuel batteries or combinations thereof. In order to realize the purpose, the technical scheme adopted by the invention is as follows:

according to a first aspect of the embodiments of the present invention, there is provided a battery pack balancing method, including the steps of: determining different groups of same-potential points in the battery pack; and connecting part or all of the same-potential points in at least one same-potential point group through a current regulation unit.

According to an embodiment, the step wherein the same potential points are connected comprises connecting the same potential points to each other two by two via the current regulating unit.

According to still another embodiment, the step of connecting the same-potential points includes connecting the same-potential points in sequence through a current regulation unit.

According to another embodiment, the step of connecting the same-potential points includes selecting one of the same-potential points in each group of the same-potential points, and connecting the remaining same-potential points to the selected same-potential point through the current regulating unit, respectively.

According to still another embodiment, the step of connecting the same-potential points includes connecting the same-potential points to the same point through current regulation units, respectively, which is called a same-potential combining point.

According to still another embodiment, the battery pack balancing method further includes: and compensation batteries are connected between part of the same-potential junction points, between the same-potential junction points and the anode of the battery pack, and/or between the same-potential junction points and the cathode of the battery pack.

According to yet another embodiment, the step of connecting the common potential points comprises connecting an active or passive equalization circuit at the common potential points.

According to another embodiment, the battery pack balancing method further comprises the step of connecting another current regulation and control unit in series in the series battery strings in the battery pack.

According to a second aspect of the embodiments of the present invention, there is provided a battery pack balancing apparatus including a current regulation unit for connecting some or all of the same-potential points in at least one group of same-potential points in a battery pack.

According to one embodiment, wherein the current regulating units are arranged in an array and each current regulating unit is provided with a terminal.

According to still another embodiment, wherein one end of each current regulating unit for connecting the same-potential points in the same-potential point group is connected to the same point, it is called a same-potential point.

According to another embodiment, the battery pack balancing device further comprises a compensation battery, which is connected between the common potential junction points, or one end of the compensation battery is connected with the common potential junction point, and the other end of the compensation battery is provided with a terminal used for connecting the positive pole of the battery pack or the negative pole of the battery pack.

According to another embodiment, the battery pack balancing device further comprises an active or passive balancing circuit connected to the same potential junction point.

According to another embodiment, the battery pack balancing device further comprises another current regulation and control unit for connecting in series battery strings in the battery pack.

According to still another embodiment, the current regulation unit includes: a resistor, a fuse, an inductor, a diode, a transistor, a switch, a relay, or a combination thereof.

According to a third aspect of the embodiments of the present invention, there is provided an active equalization circuit or a passive equalization circuit including the battery pack equalization apparatus according to the second aspect of the embodiments of the present invention.

According to a fourth aspect of the embodiments of the present invention, there is provided a battery pack including battery arrays connected to each other in series-parallel; and the current regulation and control unit is used for connecting at least one same-potential point group in the battery pack or part or all of the same-potential points in the same-potential point group with the expected potential keeping consistency.

According to an embodiment, wherein the current regulation unit comprises: a resistor, a fuse, an inductor, a diode, a transistor, a switch, a relay, or a combination thereof.

According to a further embodiment, the current regulation unit is adapted to connect the same-potential points two by two to each other, or to connect the same-potential points in sequence, or to connect each of the same-potential points to a same common-potential point, respectively, or to connect each of the same-potential points in the same-potential point group to a selected one of the same-potential points, respectively.

According to another embodiment, the battery pack further comprises a compensation battery connected between the common potential junction, between the common potential junction and the positive electrode of the battery pack, or between the common potential junction and the negative electrode of the battery pack.

According to another embodiment, the battery pack further comprises an active or passive equalization circuit connected to the common potential point.

According to yet another embodiment, the battery pack further comprises another current regulation unit for connection in a series string of series cells in the battery pack.

According to yet another embodiment, the battery includes: various chemical cells, photovoltaic cells, capacitors, supercapacitors, fuel cells, and various combinations thereof.

According to a fifth aspect of the embodiments of the present invention, there is provided an electric energy driving product, an electric system, an energy storage or power generation system, including an electric vehicle, an Uninterruptible Power Supply (UPS), a grid power plant, a communication base station, a photovoltaic module, a photovoltaic power plant and system, and various fuel cell stacks and systems, including the battery pack balancing apparatus according to the second aspect of the embodiments of the present invention, or including the battery pack according to the third aspect of the embodiments of the present invention.

According to the battery pack balancing method, the battery pack balancing device and the battery pack, the voltage balancing problem, the current balancing problem and the capacity balancing problem when batteries are connected in series and in parallel for grouping can be solved, the mismatch problems caused by inconsistency, shadow shielding and the like of various photovoltaic power generation batteries can be solved, the system reliability and the power generation efficiency are improved, and the inconsistency problem when various fuel batteries are grouped can also be solved.

The present invention will now be described more fully hereinafter by way of example with reference to the accompanying drawings, in which like reference numerals refer to like or substantially like parts.

Drawings

Fig. 1 is a schematic flow diagram of a battery equalization method according to an embodiment of the invention;

FIG. 2 is a schematic diagram illustrating a point of common potential in a battery pack according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the manner in which the same potential points are connected in a battery pack according to one embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating a manner of equalization according to one example of the invention;

FIG. 5 is a schematic diagram illustrating a manner of equalization according to yet another example of the present invention;

FIG. 6 is a schematic diagram illustrating capacity equalization by compensating batteries, according to one embodiment of the present invention;

FIG. 7 is a schematic diagram of a manner of equalization in combination with an active or passive equalization circuit, in accordance with one embodiment of the present invention;

fig. 8 is a schematic diagram of a manner of balancing by incorporating a resistor as a current regulation unit in a series string of cells in a battery pack, in accordance with one embodiment of the present invention;

FIG. 9 is a schematic diagram of equalization using a fuse, according to one embodiment of the present invention;

FIG. 10 is a schematic diagram of equalization using inductors, in accordance with one embodiment of the invention;

FIG. 11 is a schematic diagram of equalization using diodes and a combination of diodes and resistors in accordance with one embodiment of the present invention; and

fig. 12 is a schematic diagram of equalization using switches, diodes, fets, and combinations thereof, according to one embodiment of the invention.

Detailed Description

The present application relates to batteries and/or battery packs including, but not limited to, various chemical cells, photovoltaic cells, capacitors, supercapacitors, fuel cells, and the like, as well as combinations thereof of the same or different types. The method can be used for series-parallel combination of various low equivalent impedance devices, solves the problem of consistency, and even can be used for solving the balance problem when a plurality of diodes are connected in series-parallel, a plurality of triodes are connected in series-parallel, and a plurality of inductance coils are connected in series-parallel in a group for application.

As shown in fig. 1, a schematic flow chart of a battery pack balancing method according to an embodiment of the present invention mainly includes: a determination step 101, and a connection step 102. This is described in detail below.

According to the battery pack balancing method provided by the embodiment of the invention, the following steps are performed in combination with a battery combination mode: for m × n cells (or battery packs), where m ≧ 2, n ≧ 2, cell numbers B11 through Bmn. Every n batteries are connected in series to form a battery string, and m battery strings are total. Each string of batteries starts from the negative pole of the battery string, and the first string of batteries is formed by connecting B11 to B1n in series; and by analogy, the m-th string of batteries is formed by connecting Bm1 to Bmn in series. In the first string, the connection point between B11 and B12 is J11; by analogy, the connection point between B1n-1 and B1n is J1 n-1; in the m-th string of cells, the connection point between Bm1 and Bm2 is Jm1, and the connection point between Bmn-1 and Bmn is Jmn-1, as shown in fig. 2 (a).

According to the embodiment of the invention, under the condition that all battery performance parameters in the battery pack are completely the same, a set of connection points of the positive and negative electrodes of all batteries which are connected in series and have the same potential in the whole battery pack is defined as a point group with the same potential; alternatively, a set of connection points connecting the positive and negative electrodes of the cells in series, which should be the same and desired to have the same potential when designing the battery pack, is defined as a group of the same potential points. The connecting points in the same group of the same-potential points are the same-potential points, and the average value of the potentials of the same-potential points is defined as the potential of the group of the same-potential points. And defining the point at which the other ends of two or more current regulation units respectively connected with the same potential point in the same potential point group are connected together as a same potential composite point.

For example, for m battery strings consisting of n batteries, the m battery strings are connected in parallel to form a battery pack which is connected in series and then connected in parallel. The positive poles of all the battery strings are connected together to form the total positive pole of the battery pack, and the negative poles of all the battery strings are connected together to form the total negative pole of the battery pack, so that the battery pack has a potential reference point. Under the condition that all the battery performance parameters are completely the same, the potentials of the connecting points of J11 and J21 … Jm1 are completely the same; …, respectively; the potentials of the points J1n-1 and J2n-1 … Jmn-1 are the same, and the connecting points of the positive electrode and the negative electrode of the batteries connected in series form a same-potential point group which is the same as each other; alternatively, if the potential of the points is desired to be uniform when the battery performance parameters are not uniform, the connection points of the positive and negative electrodes of the series-connected batteries, the potentials of which are desired to be uniform, are formed into a group of points of the same potential, which are points of the same potential with each other, as shown in fig. 2 (b).

For the m battery strings shown in fig. 2(b), a connection point is taken out in each string, for example, the first string is taken out of J12, and so on, J22, … and Jm2 are taken out, and these points are directly connected to form a potential reference point. In each battery string, the connection points which are located above and below the potential reference point and have the same battery pitch, such as J13, J23, …, Jm3 and the like, or J11, J21 …, Jm1 and the like, under the condition that all battery performance parameters are completely consistent, the connection points of the anode and the cathode of the batteries connected in series have the same potential, or when the potentials of the connection points are expected to be consistent, the connection points respectively form a same-potential point group, and all points in the same-potential point group are the same-potential points, as shown in fig. 2 (c).

For a battery pack consisting of different or even different types of batteries, if it is desired that the connection point potentials in different strings are consistent with the connection point potentials in other strings, the collection of points forms a group of points with the same potential, and the points are points with the same potential. For example, a string of nominally 12V lead-acid batteries is formed by connecting six lead-acid batteries B11, B12, B13, B14, B15, and B16 in series, the connection point between B11 and B12 is J11, and so on, and the connection point between B15 and B16 is J15. The other string of nominal 12V lithium iron phosphate batteries is formed by connecting four lithium iron phosphate batteries B21, B22, B23 and B24 in series, the connection point between B21 and B22 is J21, and the like, and the connection point between B23 and B24 is J23. If the positive electrodes of two strings of 12V batteries of different types are connected together and the negative electrodes are connected together, the two strings of batteries are connected in parallel to form a battery pack. If it is desired that the potential of the series connection point J13 of the lead acid battery and the series connection point J22 of the lithium iron phosphate battery be identical, J13 and J22 form a group of points of the same potential, which are points of the same potential with respect to each other, as shown in fig. 2 (d).

For another example, a battery pack is composed of several sub-battery packs, wherein each of the

sub-battery packs

1 and 2 comprises at least two batteries connected in series. The sub-battery pack 1 comprises two batteries Bx1 and Bx2 which are connected in series, and the series connection point is Jx; the sub-battery pack 2 comprises two batteries By1 and By2 which are connected in series, and the series connection point is Jy. If it is desired that the potentials of the series connection points Jx and Jy in the two sub-battery packs coincide, they constitute a group of same-potential points, which are the same-potential points as shown in fig. 2 (e).

After the groups of the same-potential points in the battery pack are determined, in one embodiment, part or all of the same-potential points in at least one group of the same-potential points can be connected through the current regulation unit as needed to limit and regulate the current between the same-potential points, so as to balance the current, the voltage and the capacity of the battery. The current regulation unit includes, but is not limited to, various resistors, fuses, inductors, diodes, transistors, switches, relays, or combinations thereof. The following description will take a resistor or a resistor network as an example.

The same potential points are connected through a resistor or a resistor network to limit and adjust the current between the same potential points. When the same-potential points are connected through the resistor, two of the same-potential points can be connected through the resistor, as shown in fig. 3 (a); or may be connected in sequence, such as one after the other, as shown in fig. 3 (b); preferably, however, in one embodiment, one resistor is connected to each equipotential point in the group of equipotential points, and then the other ends of all the resistors are all connected together in parallel, i.e., at the equipotential point, as shown in fig. 3(c) as J1. Fig. 3 illustrates an example of a group of four identical-potential points in four battery strings, and the other battery groups are completely similar.

The theoretical basis of the present invention is based on statistical error theory, assuming that the parameters of the cells used for grouping conform to a normal distribution, and the degree of dispersion is measured by the coefficient of variation (i.e., standard deviation divided by mean), generally expressed as CV. The following description will be made with respect to a case where P × Q cells are grouped. Assuming that the voltage variation coefficient of the P × Q cells is CVv, the internal resistance variation coefficient is CVr, and the capacity variation coefficient is CVc; the average voltage of the P cells is VP, the average internal resistance is RP, and the average capacity is CP. According to the error theory, the coefficients of variation of the voltage sum, the internal resistance sum and the capacity sum of the P cells are equal to the coefficient of variation of the mean value of the corresponding P parameters, which is the corresponding coefficients of variation CVv, CVr and CVc of the P × Q cells divided by the square root of P. The average voltage of the Q cells is VQ, the average internal resistance is RQ, and the average capacity is CQ. According to the error theory, the variation coefficients of the voltage sum, the internal resistance sum and the capacity sum of the Q batteries are equal to the variation coefficient of the average value of the corresponding Q parameters, namely the variation coefficients CVv, CVr and CVc of the corresponding PxQ batteries divided by the square root of Q. Therefore, the probability of extracting the voltage sum, the internal resistance sum and the capacity sum of the same number of the plurality of batteries is remarkably reduced as the dispersion degree and the average value thereof are the same. Even if the parameters of the batteries are not normally distributed, the values are always distributed above and below the average value, and the values have different magnitudes, so that the difference of the average values of the parameters of the batteries which extract the same number is also obviously reduced, and the difference of the voltage sum, the internal resistance sum and the capacity sum of the batteries which extract the same number is also obviously reduced.

For the battery pack which is connected in series and then connected in parallel, namely P multiplied by Q batteries, every Q batteries are connected in series to form a P string, and then the P string batteries are connected in series and then connected in parallel. For the P series of batteries, because the total voltage and the internal resistance of each series of batteries are the sum of the voltage and the internal resistance of Q batteries, according to the error theory, the variation coefficient is the variation coefficient of the corresponding parameters of the PxQ batteries divided by the square root of Q, and the dispersion degree is obviously reduced. The current inside each series of batteries after being connected in parallel is directly related to the sum of the voltage and the internal resistance of the series of batteries, so that the difference of the current flowing by each series of batteries is obviously reduced particularly when the Q is larger. And the current of each battery in each string is the same, so that the current flowing by each battery of all the PxQ batteries is basically consistent.

For the battery pack which is connected in parallel and then connected in series, namely, P multiplied by Q batteries are connected in parallel to form Q batteries, and then the Q batteries are connected in series. For Q cell combinations, the voltage of each cell combination is approximately the average of the P cell voltages, and the total capacity of each cell combination is the sum of the P cell capacities. According to the error theory, the variance of the sum and the variance of the average are the variance of the individual cell parameter divided by the square root of P. Therefore, the voltage difference between the Q cell pairs is significantly reduced, particularly when P is large; and the voltage of each battery in each battery pack is the same, so that the voltage of each of all the P multiplied by Q batteries is basically consistent. At the same time, the capacity and mutual difference of the Q cell pairs is significantly reduced, especially when P is large.

Therefore, the consistency of the current of the battery pack after series connection is obviously superior to that of the battery pack after series connection. The consistency of the voltage of the battery pack which is connected in parallel and then in series is obviously superior to that of the battery pack which is connected in series and then in parallel.

After the battery packs are connected according to the equalizing method of the embodiment of the invention, the combination of the battery grouping modes of firstly connecting in parallel and then connecting in series and firstly connecting in series and then connecting in parallel is practical, the equalizing method has the advantages of the two modes, and simultaneously overcomes the defects of the two modes. Specific examples are as follows.

In the embodiment of the invention, the m same-potential points are connected through a current regulation unit (such as a resistor and the like). When the voltages at the same potential points are different, current flows between the same potential points, so that the potentials of the m same potential points tend to the potential of the same potential point group. Finally, when the same-potential point potential is equal to the same-potential point group potential, the current between the same-potential points is zero. Therefore, the battery pack is similar to the battery pack which is connected in parallel first and then connected in series, has the advantage of more consistent voltage, and overcomes the defect that the voltage of the series batteries is possibly greatly different in the battery pack which is connected in series first and then connected in parallel.

When the potentials of the same-potential points are close to be consistent, the current flowing through the resistor between the same-potential points is close to zero, so that the currents of the n batteries in each string tend to be consistent. Because the voltage and the internal resistance of each battery string are the sum of the voltage and the internal resistance of the n batteries, the current difference of the m battery strings is obviously smaller than that of the m single batteries when the m single batteries are connected in parallel, so that the currents of all the m multiplied by n batteries are basically consistent, and the advantage that the currents of the battery packs connected in parallel after series are more consistent is achieved. When the potentials at the same potential point are inconsistent, the current regulation and control unit regulates and controls the current between the same potential points, so that the defect that the current of the parallel batteries in the battery pack which is connected in parallel and then in series is possibly greatly different is overcome.

The battery voltage connected with the same potential point is not always completely the same but the potential of the same potential point gradually tends to be consistent compared with a circuit which is connected in parallel and then connected in series. When the resistor between the same potential point has current, compared with the battery packs which are connected in series and then in parallel, the current of the single battery in each battery string is not always the same, but gradually tends to be consistent with the reduction of the voltage difference of the same potential point. By selecting proper resistance values of the resistors between the same-potential points, the current between the same-potential points can be adjusted, the voltage balancing speed between the same-potential points can be adjusted, and the inconsistent degree of each string of current can be adjusted.

After the same-potential points are connected through the resistor, current can flow between the same-potential points, and the method is similar to a battery pack which is connected in parallel and then in series. Compared with the discrete degree of the capacity of a single battery, the discrete degree of the capacity of the battery between the positive electrode and the negative electrode of the battery pack and different groups of the same-potential points or the same-potential points is smaller in probability, and the discrete degree of the capacity of the battery between the positive electrode and the negative electrode of the battery pack is the same as that of the battery pack which is connected in parallel and then connected in series.

The method, apparatus and battery according to embodiments of the present invention are further illustrated by the following specific examples.

1. A 2 × 2 total of four cells is exemplified as a battery pack, where m is 2 and n is 2.

There are two common grouping of four cells. One is to connect two in parallel and then in series, as shown in fig. 4 (a). Wherein batteries B11 and B21 are connected in parallel, and batteries B21 and B22 are connected in parallel. The connection point of the negative electrode of B11 and the negative electrode of B21 is the negative electrode of the battery pack, and the connection point of the positive electrode of B12 and the positive electrode of B22 is the positive electrode of the battery pack.

The other two are connected in series and then in parallel, as shown in fig. 4 (b). Wherein B11 and B12 are connected in series, and B21 and B22 are connected in series. The connection point of the negative electrode of B11 and the negative electrode of B21 is the negative electrode of the battery pack, and the connection point of the positive electrode of B12 and the positive electrode of B22 is the positive electrode of the battery pack. The junction of the positive electrode of B11 and the negative electrode of B12 is J11, and the junction of the positive electrode of B21 and the negative electrode of B22 is J21.

With the method, apparatus or battery pack according to the embodiment of the present invention, after four batteries are connected in series and then in parallel, the connection points J11 and J21 are the same potential point group, and a resistor R121 as a current regulation unit is connected therebetween, as shown in fig. 4 (c). When the performance parameters of the four batteries are inconsistent, the potentials at the same potential points J11 and J21 are different. Since the resistor R121 is connected to the same potential points J11 and J21, the potentials at the same potential points J11 and J21 tend to be uniform, and the four-cell voltage uniformity is improved. When the potentials at the J11 point and the J21 point tend to be consistent, and the current flowing through the R121 point is zero, the equalization method and the battery pack circuit connected according to the embodiment of the invention have the advantage of more consistent current as the battery pack circuit connected in series and then in parallel. Due to the action of the R121, the current inconsistency of the battery packs which are connected in parallel and then connected in series is reduced, and the problem of large current difference caused by poor consistency of two batteries which are directly connected in parallel can be solved. By means of proper R121 resistance values, when the four batteries are inconsistent, voltage consistency and current consistency of the four batteries during operation can be improved.

In which the resistor R121 is a current regulation unit according to an embodiment of the present invention, the resistor 121 and its terminals may constitute a battery pack balancing apparatus according to an embodiment of the present invention, as shown by a dotted line box of fig. 4 (c).

2. A total of nine cells, 3 × 3, where m is 3 and n is 3, will be exemplified.

Nine batteries are connected in series and then in parallel. The negative electrode of B11 is the negative electrode of the first battery string, the positive electrode of B11 is connected with the negative electrode of B12, the connection point is J11, the positive electrode of B12 is connected with the negative electrode of B13, the connection point is J12, and the positive electrode of B13 is the positive electrode of the first battery string. The second string and the third string are similar to the first string. The negative poles of the three strings of batteries are connected together to form the negative pole of the battery pack, and the positive poles of the three strings of batteries are connected together to form the positive pole of the battery pack, namely the three strings of batteries are connected in parallel.

If it is desired that the potentials of J11, J21, and J31 are always kept the same, then the three connection points of J11, J21, and J31 constitute a first group of equipotential points that are the same as each other. Similarly, three connecting points of J12, J22 and J32 form a second group of same-potential points which are same-potential points.

As shown in fig. 5, according to the equalizing method and the battery pack of the embodiment of the present invention, the same-potential points J11, J21, and J31 of the first same-potential point group are connected through a current regulating unit, and the same-potential points J12, J22, and J32 of the second same-potential point group are connected through a current regulating unit. The current and the voltage of each battery are balanced by adjusting and controlling the current among the same potential points, and the characteristic of good consistency of the capacity of the battery pack which is connected in parallel and then connected in series is kept. The equalizing method according to the embodiment of the present invention will be described below by taking an example of connecting the same potential point through a resistor as a current regulation unit.

2.1. The connection circuit when performing equalization according to one embodiment is shown in fig. 5(a) for nine cells in a 3 × 3 battery pack. Six resistors are adopted, one end of R11 is connected with J11, one end of R21 is connected with J21, one end of R31 is connected with J31, the other ends of R11, R21 and R31 are connected together to form J1, and J1 is a same-potential junction point; one end of R12 is connected with J12, one end of R22 is connected with J22, one end of R32 is connected with J32, the other ends of R12, R22 and R32 are connected together to form J2, and J2 is another homojunction point.

Wherein R11, R21, R31, R12, R22 and R32 may be independently arranged, one end of each of R11, R21 and R31 is connected together as a common potential point, one end of each of R12, R22 and R32 is connected together as another common potential point, and the other ends of the six resistors are provided as terminals for connection with the common potential point in the battery pack, thereby forming a battery pack equalizing device according to an embodiment of the present invention, as indicated by the portion framed by the broken line in fig. 5 (a).

With the battery pack circuit shown in fig. 5(a), the problems of voltage uniformity, current uniformity, and capacity uniformity of the cells are all improved.

2.2. When nine batteries of 3 × 3 are grouped, a connection circuit of the battery pack when equalization is performed according to another embodiment is shown in fig. 5 (b). With six resistors, R121 is connected between J11 and J21, R131 is connected between J11 and J31, and R231 is connected between J21 and J31; r122 is linked between J12 and J22, R132 is linked between J12 and J32, and R232 is linked between J22 and J32. The circuit shown in fig. 5(b) is equivalent to the circuit shown in fig. 5(a) in terms of circuit principle, and therefore, the same action and effect as those of fig. 5(a) are obtained.

Similarly, the six resistors shown in fig. 5(b) may be independently arranged, wherein each of the six resistors is provided with terminals for connecting to the same potential points in the battery pack, thereby forming a battery pack equalizing apparatus according to another embodiment of the present invention, as indicated by the portions outlined by the dotted lines in fig. 5 (b).

2.3. According to yet another embodiment, the connection to the same potential point may also use a combination of the above circuits. Specifically, as shown in fig. 5(c), one of the same-potential points in each group of the same-potential points serves as a common terminal, and the remaining same-potential points are connected to the common terminal through a current regulation unit (e.g., a resistor).

Similarly, the resistors framed by the broken lines in fig. 5(c) may be independently arranged with one ends of each of three resistors connected together, with one ends of each of the other three resistors connected together, with the other ends and two interconnected ends of each of the six resistors serving as terminals, and with the four terminals of the remaining two resistors serving as terminals for connection to points of the same potential in the battery pack, thereby forming a battery pack equalizing device according to yet another embodiment of the present invention.

3. According to the method and the battery pack of the embodiment of the invention, the dispersion degree of the battery capacity sum between the positive electrode and the negative electrode of the battery pack and different groups of the same-potential points or the same-potential combination points is reduced in probability as the battery packs connected in parallel and then in series, but the complete consistency cannot be ensured. The battery capacity sum can be adjusted and balanced by connecting the small-capacity batteries in parallel between the same-potential junction points corresponding to the small-capacity batteries or the positive and negative electrodes of the battery pack according to the capacity sum difference, so that the batteries are more balanced and consistent. This small capacity battery is defined as a compensation battery. For example, in the circuit shown in fig. 5(a), when the sum of capacities of three batteries B12, B22 and B32 is significantly smaller, a compensation battery B42 may be additionally provided between the same-potential junctions J1 and J2 according to the size of the capacity and the deviation, so that the sum of capacities of the batteries between the same-potential junctions J1 and J2 is more consistent with the sum of capacities of other batteries, as shown in fig. 6.

Fig. 6 only compensates the sum of capacities of the cells between a pair of same-potential junction points J1 and J2, and other cells in the battery pack can also compensate according to the capacity difference; according to another embodiment, a resistor or a current regulation unit may be connected in series with the compensation battery B42 in the circuit of fig. 6 to adjust the current of B42 during operation.

Similarly, in the battery pack equalizing apparatus according to an embodiment of the present invention described above with reference to fig. 5(a), the compensation battery may be connected between two connection points (i.e., two common-potential junctions) formed by connecting respective one ends of three resistors to each other, or between the positive electrode of the battery and the common-potential junction, or between the negative electrode of the battery and the common-potential junction, so that the battery pack equalizing apparatus according to yet another embodiment of the present invention may be formed, as indicated by the dashed line in fig. 6.

4. In the circuit shown in fig. 5(a), the voltage equalization of the batteries is only achieved to the same extent as that of the battery pack connected in parallel and then in series at most, and only the problem that the current of the batteries connected in parallel in the battery pack connected in parallel and then in series is possibly too large is solved. The method and the battery pack according to the embodiment of the invention are combined with the existing passive equalization or active equalization method and circuit of the series battery pack, so that the voltage equalization problem during battery grouping can be better solved. Fig. 7 is a schematic diagram of a nine cell battery circuit according to one embodiment, fig. 5(a) combined with an active equalization or passive equalization circuit. The active equalization circuit or the passive equalization circuit is combined, so that the voltages among the cathode of the battery pack, the same-potential junction points J1 and J2 and the anode of the battery pack are more equalized, and the potential of each same-potential junction point gradually tends to the same-potential junction point potential, so that the voltages of all the batteries are equalized.

Similarly, in the battery pack equalizing device according to an embodiment of the present invention described above with reference to fig. 5(a), the active equalizing circuit or the passive equalizing circuit may be connected at two connection points (i.e., two common-potential points) respectively connected to each other by one end of each of the three resistors, so that the battery pack equalizing device according to still another embodiment of the present invention may be formed, as framed by the broken lines in fig. 7.

5. In the circuit shown in fig. 5(a), the current balance of the batteries is achieved only to the same extent as that of the battery pack connected in series and then in parallel at most. The current regulating unit is connected in series in each string of batteries to limit and regulate the current in each string of batteries, so that the currents between strings can be more balanced and consistent, and the currents of all batteries are consistent. The current of each battery string is limited and adjusted, and the influence of the current regulation units connected in series on the potential of the same potential point is considered, so that the optimal scheme is that the current regulation units are adopted in the middle of each battery string. As shown in fig. 8(a), when twelve batteries are grouped according to an embodiment, three resistors Ri1, Ri2, Ri3 are respectively connected in series in the middle of each battery string as current regulation units to equalize the currents in the three battery strings. When the current of a certain string of batteries is large, the voltage drop on the resistor is increased, so that the current of the string of batteries is reduced. The current regulation units according to fig. 8(a) are resistors Ri1, Ri2, Ri3, but in other embodiments, various types of resistors, fuses, inductors, diodes, transistors, switches, relays, or combinations thereof may be used instead.

Similarly, in the battery pack equalization circuit according to one embodiment of the present invention shown in fig. 8(a), the resistors Ri1, Ri2, Ri3 as additional current regulation units and other resistors connected to the same potential point may be independently arranged and the corresponding terminals provided, so that a battery pack equalization apparatus according to still another embodiment of the present invention may be formed, as shown in the portion outlined by the dotted line in fig. 8 (a).

Batteries with high energy density generally have low power density, and batteries with high power density have low energy density. The method and the battery pack according to the embodiment of the invention also provide an equalization scheme when batteries with different energy densities and power densities are mixed to form a group. According to one embodiment, as shown in fig. 8(B), the batteries B41, B42, B43 are high power density batteries, and the other batteries are high power density batteries, and can withstand a smaller maximum current. The negative pole of the battery pack is led out from the negative pole of the battery B41, the positive pole of the battery pack is led out from the positive pole of the battery B43, and the high-power and high-current charging and discharging of the battery pack are carried by the batteries B41, B42 and B43. The resistors Ri1, Ri2 and Ri3 with different resistances are selected to adjust the current of the batteries in other strings, and of course, the resistors Ri1, Ri2 and Ri3 may also be connected in series in the middle of the battery string as shown in fig. 8 (a).

Similarly, the frame portion of fig. 8(b) may be independently arranged and provided with corresponding terminals, so that a battery pack balancing apparatus according to still another embodiment of the present invention may be formed.

In yet another embodiment, the solutions shown in fig. 6, 7 and 8 can be combined to make the capacity, voltage and current of the batteries in the battery pack consistent.

The resistance value of the resistor connected between the same potential points in the battery pack circuit according to the embodiment of the present invention may be determined according to the requirements of the battery capacity, the internal resistance, the voltage uniformity, the current uniformity, and the like. The voltage consistency is required to be good, and the resistance value is required to be small; the current consistency is required to be good, and the resistance value is required to be larger.

The equalization method, apparatus and battery pack according to various embodiments of the present invention have been described above, and are actually a battery grouping method in which resistors are used to regulate and control the current between points of the same potential. The method, apparatus and battery circuit using resistors as current regulation units for other m x n cells in a pack, where m ≧ 2 and n ≧ 2, are similar to the embodiments described above.

The resistor in the above embodiment may be a general resistor, or may also be a negative temperature coefficient thermistor (NTC) or a positive temperature coefficient thermistor (PTC) according to the requirement. By using the thermistor, the current at different temperatures between the same potential point can be adjusted and controlled. When a voltage difference exists between the same potential points, when a negative temperature coefficient thermistor is used, the higher the temperature is, the smaller the resistor is, the higher the current between the same potential points corresponding to the resistor is, and the faster the voltage balance is; when the positive temperature coefficient thermistor is used, the higher the temperature is, the larger the resistor is, the smaller the current between the corresponding same potential points of the resistor is, the slower the voltage balance is, and the better the battery current balance is. When in specific use, the thermistor and the common resistor can be used in series-parallel combination.

The battery pack balancing apparatus including the current regulation and control unit and the battery pack according to the embodiments of the present invention are described above by taking a resistor as an example in describing the method according to the embodiments of the present invention. However, the current regulation unit for battery grouping according to the embodiment of the present invention is not limited to various resistors, and may be implemented in various forms such as various fuses, inductors, diodes, transistors, switches, relays, or a combination circuit thereof, as described below.

In one embodiment, it is an option to replace the resistor with various fuses, such as fuses or fuses. Because the fuse generally has a certain resistance value, the fuse with a proper resistance value is selected, and the same circuit effect as that of the resistor can be achieved; meanwhile, when the current between the same potential points exceeds the fusing current of the fuse or the fuse tube, the fuse is disconnected, and the current is isolated from the large same potential points. The fuse may be a recoverable fuse. When the voltage difference between the same potential points is large and the current flowing through the fuse between the same potential points is overlarge, the corresponding fuse is disconnected, and the circuit is changed into a circuit which is connected in series and then connected in parallel, so that the circuit has better current balance performance; when the current becomes small, the fuse is recovered and switched on again, and the voltage balancing function is recovered. Meanwhile, the problems that the current is too large each time, and the fuse is blown and needs to be manually maintained can be avoided.

Fig. 9(a) is a circuit diagram in which resistors in the circuit of fig. 5(a) are replaced with fuses, and similarly, resistors are replaced with other fuses. The current limiting resistors Ri1, Ri2 and Ri3 in each battery string in fig. 8(a) are replaced by fuses, which are opened to protect against faults when excessive fault current occurs in the battery string. All resistors in fig. 8(a) are replaced by fuses, as shown in fig. 9(b), since the fuses have certain resistors, the circuit can play a role of equalizing voltage and current like the circuit in fig. 8(a), and meanwhile, when any battery in the battery pack is short-circuited, the fuses in the corresponding battery string and the fuses connected with the same potential point are disconnected, so that the faulty battery is disconnected from the battery pack, and other batteries in the whole battery pack can be protected to work.

In yet another embodiment, the resistors in the above embodiments may be replaced with various inductors. The inductor generally has a certain resistance value, and when the inductor is manufactured, the direct-current resistance of the inductor is a required value, so that the same circuit effect as that when the resistor is adopted can be achieved. Meanwhile, the inductor can inhibit the instantaneous change of the current; when the battery pack is charged or discharged with large current, the inductor can prevent instantaneous large current between points with the same potential, and the effect of balancing the working current of each battery when the current changes is achieved. Fig. 10(a) is a battery circuit diagram in which an inductor is used in place of a resistor in the circuit of fig. 5 (a). In fig. 10(b), the resistors Ri1, Ri2 and Ri3 in fig. 8(b) are replaced by the inductances Li1, Li2 and Li3, so that the function of equalizing and adjusting the circuit in fig. 8(b) can be maintained, and the change of the series current of the battery with the series inductance can be smooth. Of course, the inductors Li1, Li2, and Li3 may be connected in series in the middle of the battery string as shown by the resistors Ri1, Ri2, and Ri3 in fig. 8 (a).

According to a further embodiment, the above-connected resistors can be replaced by various diodes or devices with a certain conduction voltage drop. The diode has a conduction voltage drop when conducting, and when the voltage difference at the same potential point is larger than the conduction voltage drop of the diode, the diode conducts to play a role in limiting the voltage difference, as shown in fig. 11. Fig. 11(a) is a view showing that the resistor R121 connected between the same potential points J11 and J21 in fig. 4(c) is replaced by a diode D121, which has a unidirectional conductivity, and the direction of the diode can be selected as required, and the diode can make the potential of J11 higher than that of J21 by at most one diode conduction voltage drop. Fig. 11(b) is a diagram showing that two diodes D1211 and D1212 are connected in anti-parallel instead of a single diode, and the voltage between J11 and J21 can be limited to one diode conduction voltage drop.

Due to the unidirectional conductivity of the diode, it is preferred that the diode be used with other devices or circuits, such as a parallel resistor on the diode. When the voltage difference of the same potential point is smaller than the conduction voltage drop of the diode, the resistor plays a role in balancing the potential of the same potential point; when the voltage between the same potential points is larger than the conduction voltage drop of the diode, the diode is conducted and plays a role of voltage balance together with the resistor; when the voltage difference between the same potential points is large, the current flowing through the diode is large, and the voltage difference between the same potential points can be rapidly kept within the conduction voltage drop of the diode.

The circuit of fig. 11(c) has a similar effect to the circuit of fig. 5(b), but is capable of limiting the voltage difference between the same potential points to within one diode conduction drop. The circuit shown in fig. 11(d) can make the potentials of the same-potential points J11 and J21 higher than the potential of the same-potential point J31 by one diode conduction voltage drop at most.

In the battery circuit shown in fig. 11(e), the anodes of the diodes connected in parallel to the resistors are connected to a point of common potential and the cathodes are all connected in parallel, allowing the highest cell voltage to be maintained at about one diode drop above the average cell voltage, with good protection against overvoltage. In the circuit shown in fig. 11(f), the cathodes of the diodes connected in parallel to the resistor are connected to the same potential point, and the anodes are all connected in parallel, so that the lowest battery voltage can be kept about one diode drop lower than the average battery voltage, and the circuit has good undervoltage prevention characteristics. In the circuit shown in fig. 11(g), two anti-parallel diodes are connected in parallel to the resistor, so that the difference between the same potential point and the average potential can be kept within a diode conduction voltage drop range.

The low-voltage difference diode, such as a Schottky diode, a germanium diode and the like, can keep the voltage difference between points with the same potential in a small range, and can be used in photovoltaics, and the diode can also be made in photovoltaic devices by using semiconductor materials. The diode is adopted, so that when the diode is conducted, the equalizing current larger than the resistance can be obtained. Similarly, various fuses, inductors, etc. may be used in combination with the diodes, and the circuit configuration thereof is not shown.

In still another embodiment, the resistors connected in the above embodiments may be replaced with various switches, relays, or various semiconductor switches. The switch is controlled to be conducted, and the battery pack becomes a battery pack which is connected in parallel and then in series, so that the battery pack has the characteristic of good voltage consistency; the control switch is switched off, and the battery pack becomes a battery pack which is connected in series and then in parallel, so that the battery pack has the characteristic of good current consistency.

A field effect transistor (MOSFET) semiconductor switch, itself, may be used as the adjustable resistor. The circuit comprising the field effect transistor is adopted, and the gate voltage of the field effect transistor is controlled to enable the field effect transistor to work in a linear working area. The on-resistance of the field effect transistor is adjusted and controlled, so that the current at the same potential point is adjusted and controlled under different conditions and requirements, and the effect of balancing is adjusted and controlled. Meanwhile, the field effect transistor can be completely switched on or off, and the effect same as that of using a switch is achieved.

When the battery pack is charged and discharged at a high current, such as in a quick charging stage or when an electric automobile is accelerated, the switch or the semiconductor switch is switched off, and the circuit becomes a circuit which is connected in series and then in parallel, so that the circuit has good current balance characteristic and prevents the current of individual batteries from being overlarge; when the working current in the battery pack is small or no working current exists, for example, when the small current is charged at the end of charging or at the end of discharging, the control switch is turned on, the circuit has the characteristic of being connected in parallel and then connected in series, the voltage balance characteristic is good, and overvoltage or undervoltage of individual batteries is prevented.

According to one embodiment, as shown in fig. 12(a), is a battery circuit in which the resistor R121 connected between the same potential points J11 and J21 in fig. 4(c) is replaced with a switch or relay switch S121. Fig. 12(b) shows a battery circuit in which the resistor R121 connected between the same potential points J11 and J21 in fig. 4(c) is replaced by a fet M121, in which the diode is an antiparallel diode of fets, and this diode can make the potential of J11 at most one diode conduction drop higher than the potential of J21. Fig. 12(c) is a battery pack circuit in which all resistors in the circuit of fig. 5(b) are replaced with switches. Fig. 12(d) shows a battery pack circuit in which all resistors in the circuit of fig. 5(a) are replaced with mosfet switches. Fig. 15(e) shows a battery pack circuit in which the current regulation resistors Ri1, Ri2, Ri3 in the circuit of fig. 8(a) are replaced by mosfet switches Mi1, Mi2, Mi3, and the charging and discharging currents of the corresponding battery strings can be adjusted by controlling Mi1, Mi2, Mi3, or the fet switches are turned off to turn off the discharging currents of the corresponding battery strings, so that the batteries in the battery strings can only be discharged by the current regulation units connected to the same potential junction point. Other circuits that employ switches are not listed here.

The above describes only a partial scheme and a schematic circuit diagram or a schematic block diagram of the equalizing method, the equalizing device and the battery pack according to the embodiment of the present invention by way of example, wherein the current regulating unit may actually employ a circuit including various resistors, fuses, inductors, diodes, transistors, switches, relays, or various combinations thereof, which are not listed herein. Similarly, among the various battery pack equalizing apparatuses exemplified by the above resistors, the battery pack equalizing apparatuses according to other embodiments of the present invention may also be constructed by replacing the resistors as the current regulating unit with various fuses, inductors, diodes, transistors, switches, relays, or various combinations thereof, as shown by the dashed-line frame portions in fig. 9 to 12. In addition, in the various embodiments described above, when the current regulation and control units in the battery pack equalization apparatus according to the embodiments of the present invention are independently arranged, they may be arranged in an array form, and they may be arranged on various substrates while making corresponding connections and providing corresponding terminals. But preferably, in one embodiment, the current regulating unit may be disposed on the PCB board; it is also preferable that, in one embodiment, the current regulating unit is formed on the PCB, for example, when a resistor, an inductor or a fuse is used as the current regulating unit, the resistor, the inductor or the fuse is made of copper foil on the PCB.

The method and the device for balancing the current and the voltage of each battery by controlling and adjusting the current between the same potential points and the battery pack formed by the method and the device are all within the scope of the invention.

According to the method and the device provided by the embodiment of the invention, a new scheme, a novel battery module and a photovoltaic system are provided for grouping photovoltaic battery modules and forming a system through the modules, the problem of mismatch caused by inconsistent devices or shadow shielding in the photovoltaic module and the system can be effectively solved, the faults of photovoltaic devices are reduced, and the power generation efficiency of the system is improved. The method and the device according to the embodiment of the invention can also solve the problem of inconsistency when a plurality of various fuel cells are grouped.

Various battery modules or circuits can be formed by the equalization method, the equalization device and/or various battery packs according to the embodiment of the invention. These battery modules or circuits can be implemented in various electric energy driving products or electric systems including energy storage or power generation, such as various transportation vehicles, various energy storage systems, power grid equipment, Uninterruptible Power Supplies (UPS), communication base stations, photovoltaic modules, photovoltaic power stations and systems, various fuel cell stacks and systems, and so on. It will be readily understood by those of ordinary skill in the art that it is not described in detail herein.

In addition, the battery pack balancing device according to the above embodiments of the present invention may be further incorporated into an existing active balancing device circuit or a passive balancing circuit, which will be easily understood by those skilled in the art and will not be described in detail herein.

The present invention has been described above with reference to specific examples, but the present invention is not limited to these specific examples. It should be understood by those skilled in the art that various modifications, equivalents, changes, and the like can be made to the present invention, for example, by dividing one step or component in the above-described embodiments into two or more steps or components, or by conversely putting the functions of two or more steps or components in one step or component. However, such variations are within the scope of the invention as long as they do not depart from the spirit of the invention. In addition, certain terminology is used in the description and claims of the present application for purposes of description only and is not limiting. Furthermore, the various references above to "one embodiment," "another embodiment," and so forth, refer to different embodiments, which may, of course, be combined in whole or in part in a single embodiment.

Claims

A battery pack equalization method, comprising the steps of:

determining different groups of same-potential points in the battery pack; and

and connecting part or all of the same-potential points in at least one same-potential point group through a current regulation and control unit.
The battery equalization method of claim 1 wherein the step of connecting points of common potential comprises: connecting the same-potential points with each other two by two through the current regulation unit.
The battery equalization method of claim 1 wherein the step of connecting points of common potential comprises: and connecting the points with the same potential in sequence through a current regulation and control unit.
The battery equalization method of claim 1 wherein the step of connecting points of common potential comprises: and in each group of the same-potential points, one of the same-potential points is selected, and the rest of the same-potential points are connected to the selected same-potential point through the current regulation and control unit.
The battery equalization method of claim 1 wherein the step of connecting points of common potential comprises: and connecting the points with the same potential to the same point through a current regulation unit, namely the points with the same potential.
The battery pack balancing method according to claim 5, further comprising: and compensation batteries are connected between part of the same-potential junction points, between the same-potential junction points and the anode of the battery pack, and/or between the same-potential junction points and the cathode of the battery pack.
The battery pack balancing method according to claim 5, further comprising: and an active or passive equalization circuit is connected to the same potential junction point.
The battery pack balancing method according to claim 1, further comprising: and another current regulation and control unit is connected into the series battery string in the battery pack and is used for regulating and controlling the current of the battery string.
A battery pack equalization apparatus, comprising:

and the current regulation and control unit is used for connecting part or all of the same-potential points in at least one same-potential point group in the battery pack.
The battery pack balancing apparatus of claim 9, wherein the current regulating units are arranged in an array form, and each current regulating unit is provided with a terminal.
The battery equalization apparatus of claim 10 wherein each of the current regulation units for connecting points of the same potential in the same group of points of the same potential has one of its ends connected to a point of common potential.
The battery pack balancing apparatus of claim 11, further comprising:

and the compensation battery is connected between the same potential junction points, or one end of the compensation battery is connected with the same potential junction points, and the other end of the compensation battery is arranged as a terminal for connecting the anode of the battery pack or the cathode of the battery pack.
The battery pack balancing apparatus of claim 11, further comprising:

and the active or passive equalization circuit is connected to the same potential junction point.
The battery pack balancing apparatus of claim 9, further comprising:

and the other current regulation and control unit is used for being connected in the series battery string in the battery pack.
The battery pack balancing apparatus of claim 9, wherein the current regulating unit includes: a resistor, a fuse, an inductor, a diode, a transistor, a switch, a relay, or a combination thereof.
An active equalization circuit or a passive equalization circuit comprising a battery equalization apparatus according to any of claims 9 to 12, 14 and 15.
A battery pack comprising an equalising means according to any one of claims 9 to 15.
The battery pack of claim 17, wherein the battery comprises: various chemical cells, photovoltaic cells, capacitors, supercapacitors, fuel cells, or combinations thereof.
An electric energy driven product, an electric system, an energy storage or generation system, including an electric vehicle, an Uninterruptible Power Supply (UPS), grid power plant equipment, a communication base station, a photovoltaic module, a photovoltaic power plant and system, various fuel cell stacks and systems, comprising the battery pack balancing device according to any one of claims 9 to 15 or the active balancing circuit or the passive balancing circuit according to claim 16, or comprising the battery pack according to claim 17 or 18.