Active equalization circuit for high-voltage energy storage battery

Abstract

The utility model discloses an active equalization circuit for a high-voltage energy storage battery, and relates to the technical field of battery equalization. The equalization circuit comprises a first equalization circuit and a second equalization circuit, and the first equalization circuit and the second equalization circuit are connected with the positive electrode and the negative electrode of the battery; and the protection loop is arranged between the positive and negative electrodes of the battery and the equalization circuit and comprises a voltage stabilizing diode and a fly-wheel diode. The beneficial effects of the utility model are that the energy of the batteries with high voltage can be transferred to the batteries with low voltage, so that loss-free energy transfer is basically realized, the utilization rate of energy is improved, and meanwhile, the heating condition in the equalization process can be reduced; on the other hand, the batteries are managed and controlled more accurately through the active equalization system, the service life of the batteries can be prolonged, and the reliability and safety of the battery module are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery equalization, in particular to an active equalization circuit for a high-voltage energy storage battery. Background Art

[0002] As countries around the world begin to study the relevant technologies of renewable energy and chemical energy storage batteries. The current application scenarios of chemical energy storage batteries have been widely integrated into our lives. Among them, new energy vehicles, household energy storage, and industrial and commercial energy storage all require the use of chemical energy storage batteries. A very important factor in high-voltage energy storage batteries is the consistency of the battery cells. The better the consistency of the battery cells, the higher the capacity, quality and safety of the battery. However, the current technology cannot ensure that the voltage of each battery cell is exactly the same during the charging and discharging process of the battery cell, so the balancing technology is needed. Most of the battery balancing technologies on the market are passive balancing. During the balancing process of this technology, when the balancing current is too large, the resistance discharge is large, which will be accompanied by heat, heat loss and energy loss; when the balancing current is too small, when the battery pack power is large, the balancing time is relatively long and the efficiency is relatively low, and the consistency of the battery cell of the battery module cannot be guaranteed in a short time.

[0003] Therefore, an active balancing circuit for a high-voltage energy storage battery is needed to solve the above problems. Utility Model Content

[0004] Some simplifications or omissions may be made in this section and the abstract of the specification and the title of the utility model of this application to avoid blurring the purpose of this section, the abstract of the specification and the title of the utility model, and such simplifications or omissions shall not be used to limit the scope of the utility model.

[0005] In view of the above problems or problems existing in the prior art, the present utility model is proposed.

[0006] Therefore, the purpose of the present utility model is to provide an active equalization circuit for a high-voltage energy storage battery, which aims to solve the problem of energy loss of the high-voltage energy storage battery during the equalization process.

[0007] In order to solve the above technical problems, the utility model provides the following technical solutions: an active equalization circuit for a high-voltage energy storage battery, comprising a battery pack, including a first battery and a second battery, wherein the first battery and the second battery are connected in series;

[0008] A balancing circuit, comprising a first balancing circuit and a second balancing circuit, wherein the first balancing circuit is connected to the positive and negative electrodes of the first battery, and the second balancing circuit is connected to the positive and negative electrodes of the second battery;

[0009] A protection circuit is arranged between the balancing circuit and the battery pack.

[0010] As a preferred solution of the active balancing circuit for high-voltage energy storage battery described in the utility model, wherein: the first balancing circuit includes a first chip, the BATP pin of the first chip is connected to the positive electrode of the first battery, the BLAS pin is connected to the SW pin through the seventh capacitor, the BATC pin is connected to the ISET pin through the fifth capacitor and the sixth capacitor, and the third resistor is also connected in parallel at both ends of the sixth capacitor.

[0011] As a preferred solution of the active balancing circuit for high-voltage energy storage battery described in the utility model, wherein: the SW pin of the first chip is also connected to a second inductor.

[0012] As a preferred solution of the active balancing circuit for high-voltage energy storage batteries described in the utility model, an eighth capacitor is further arranged between the BATP pin and the SW pin of the first chip.

[0013] As a preferred solution of the active balancing circuit for high-voltage energy storage batteries described in the utility model, the second balancing circuit includes a second chip, the BATP pin of the second chip is connected to the positive electrode of the second battery, the BLAS pin is connected to the SW pin through a third capacitor, the BATN pin is connected to the negative electrode of the second battery, a second capacitor is further arranged between the BATN pin and the ISET pin, and a first resistor is further connected in parallel at both ends of the second capacitor.

[0014] As a preferred solution of the active balancing circuit for high-voltage energy storage battery described in the utility model, wherein: the SW pin of the second chip is also connected to the first inductor.

[0015] As a preferred solution of the active equalization circuit for high-voltage energy storage battery described in the utility model, a first capacitor and a fourth capacitor are further arranged between the BATN pin of the second chip and the BATC pin of the first chip.

[0016] As a preferred solution of the active equalization circuit for high-voltage energy storage battery described in the utility model, wherein: the second resistor and the first lamp are also connected in parallel at both ends of the third capacitor.

[0017] As a preferred solution of the active balancing circuit for high-voltage energy storage battery described in the utility model, a fourth resistor and a second lamp are connected in parallel at both ends of the seventh capacitor.

[0018] As a preferred solution of the active balancing circuit for high-voltage energy storage batteries described in the utility model, the protection circuit includes n voltage-stabilizing diodes and n freewheeling diodes, the n voltage-stabilizing diodes are connected in series, and both ends of each voltage-stabilizing diode are connected to the positive and negative electrodes of the battery with a wiring harness, and the n freewheeling diodes are also connected in series, and each freewheeling diode is also connected to the positive and negative electrodes of the battery;

[0019] Here, n is a natural number greater than or equal to 1.

[0020] The beneficial effects of the utility model are as follows: the utility model can transfer the energy of a high-voltage battery to a low-voltage battery, basically realizing lossless energy transfer, improving energy utilization, and also reducing heat generation during the balancing process; on the other hand, by more accurately managing and controlling the battery through the active balancing system, the service life of the battery can be extended and the reliability and safety of the battery module can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0022] Figure 1 The figure is a commonly used pin diagram of a chip used for an active balancing circuit of a high-voltage energy storage battery.

[0023] Figure 2 The internal functional block diagram of the chip for the active balancing circuit of the high-voltage energy storage battery.

[0024] Figure 3 The present invention is a specific circuit connection diagram of an equalization loop of an active equalization circuit for a high-voltage energy storage battery.

[0025] Figure 4 The present invention is a specific circuit connection diagram of a protection circuit of an active equalization circuit for a high-voltage energy storage battery. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0029] Example 1

[0030] Reference Figure 1~Figure 3 , which is the first embodiment of the utility model, and provides an active balancing circuit for a high-voltage energy storage battery, comprising a battery pack B, a balancing circuit 100 arranged at the positive and negative electrodes of the battery pack B, and a protection circuit 200 arranged between the battery pack B and the balancing circuit 100.

[0031] The battery pack B includes a first battery B1 and a second battery B2, which are connected in series. It should be noted that the battery pack B normally includes 30 cells, and only two cells are used here to illustrate the principle and effect of the balancing circuit 100.

[0032] Furthermore, the balancing circuit 100 includes a first balancing circuit 101 and a second balancing circuit 102. The first balancing circuit 101 is arranged at both ends of the first battery B1, and the second balancing circuit 102 is arranged at both ends of the second battery B2. The first balancing circuit 101 and the second balancing circuit 102 are identical except for the different component numbers.

[0033] Furthermore, the first balancing loop 101 is composed of a first chip U1 and its peripheral circuits, wherein the first chip U1 is an ETA3000 chip, which is based on an inductive battery balancer IC, with a balancing current of up to 2A, and adopts a control scheme with an inductor to control the balance between the two batteries; the balancing current is not affected by the heat dissipation of the package, and the balancing time can be shortened; at the same time, the chip consumes relatively little current in standby mode, which can reduce power consumption loss; the final balancing voltage between the battery voltages is very precise, and the voltage accuracy is as low as 30mV, thereby improving the performance and service life of the battery; it can be used for multi-unit stacking, and can periodically scan and detect the battery voltage. When it is not balanced, it will enter sleep mode, which better protects the battery, and has a battery charge and discharge protection function, giving priority to charging the lower battery.

[0034] Furthermore, the common pin configuration of the ETA3000 chip is as follows: the ISET pin is the balancing current setting pin; the SW pin is the switching node, connected to the inductor; the BATP pin is the voltage input pin for detecting the top battery; the BATC pin is the bottom battery pin for the sensing voltage input; the BATN pin is the negative terminal detection voltage input and common ground pin; the BIAS pin is connected to the SW pin through a capacitor.

[0035] Furthermore, the protection circuit 200 is composed of a voltage regulator diode 201 and a freewheeling diode 202. The voltage regulator diode is used to prevent abnormal connection of a certain battery cell and protect the voltage at the pin of the balancing IC connected to the battery from exceeding the rated voltage range, thereby causing damage to the chip; the freewheeling diode is used to prevent the current on the inductor from breaking through the balancing IC due to abnormal connection of the battery cell when plugging and unplugging, which can be consumed by the freewheeling diode to play a protective role.

[0036] In summary, this design connects a balancing circuit between the positive and negative electrodes of the battery, and adds a protection circuit before the current flows into the balancing circuit to protect the balancing circuit from voltage drop and other conditions that may cause chip burning during the balancing process.

[0037] Example 2

[0038] Reference Figure 1~Figure 3 , which is the second embodiment of the utility model, and is different from the first embodiment in that: this embodiment describes in detail the composition and working principle of the balancing circuit 100, and the balancing circuit 100 includes a first balancing circuit 101 and a second balancing circuit 102. The first balancing circuit 101 is connected to the positive and negative electrodes of the first battery B1, and the second balancing circuit 102 is connected to the positive and negative electrodes of the second battery B2.

[0039] Further, the first balancing loop 101 includes a first chip U1, a BATP pin of the first chip U1 is connected to the positive electrode of the first battery B1, a BLAS pin is connected to the SW pin via a seventh capacitor C7, a BATC pin is connected to the ISET pin via a fifth capacitor C5 and a sixth capacitor C6, and a third resistor R3 is connected in parallel across the sixth capacitor C6;

[0040] The SW pin of the first chip U1 is also connected to the second inductor L2;

[0041] An eighth capacitor C8 is further provided between the BATP pin and the SW pin of the first chip U1.

[0042] Further, the second balancing loop 102 includes a second chip U2, a BATP pin of the second chip U2 is connected to the positive electrode of the second battery B2, a BLAS pin is connected to the SW pin via a third capacitor C3, a BATN pin is connected to the negative electrode of the second battery B2, a second capacitor C2 is further provided between the BATN pin and the ISET pin, and a first resistor R1 is further connected in parallel at both ends of the second capacitor C2;

[0043] The SW pin of the second chip U2 is also connected to the first inductor L1;

[0044] A first capacitor C1 and a fourth capacitor C4 are further provided between the BATN pin of the second chip U2 and the BATC pin of the first chip U1 .

[0045] The second resistor R2 and the first lamp G1 are connected in parallel at both ends of the third capacitor C3; the fourth resistor R4 and the second lamp G1 are connected in parallel at both ends of the seventh capacitor C7.

[0046] It should be noted that both the first chip U1 and the second chip U2 are ETA3000 chips, and the functional block diagram of the chip is as follows: Figure 2 As shown, it includes UVLO; Timer Control; Bandgap; Battery Sense; Balance Control; Balance Current Sense; Upper Cell Driver; Lower Cell Driver; the chip integrates two MOS tubes as switches, where the upper cell driver needs to connect a 10nF capacitor to the SW pin through the BIAS pin to provide power to drive the MOS tube to turn on; the lower cell driver connects the BATN pin to ground.

[0047] The working principle of the balancing circuit 100 is as follows: the first battery B1 and the second battery B2 are connected in series, the positive electrode of the first battery B1 is connected to the BATP pin of the first chip U1, the negative electrode of the second battery B2 is connected to the BATN pin of the second chip U2, the first inductor L1 is connected between the SW pin of the second chip U2 and the second battery B2, and the second inductor L2 is connected between the SW pin of the first chip U1 and the first battery B1. For example, when the voltage of the first battery B1 is too high, the MOS tube inside the first chip U1 of the first battery B1 is controlled to be turned on, the MOS tube inside the second chip U2 of the second battery B2 is controlled to be turned off, and the second inductor L1 is connected between the SW pin of the second chip U2 and the first battery B2. The inductor L2 is charged, and the voltage of the battery cell decreases. After it decreases to a balanced voltage value, the MOS tube inside the first chip U1 is disconnected, and the MOS tube inside the second chip U2 that controls the second battery B2 is turned on. The first inductor L1 is discharged, and the voltage of the other battery cell increases to a balanced voltage value. Since the current of the inductor cannot change transiently, the charge transfer between the battery cells can be realized by alternately turning on and off the two MOS tubes in sequence, so as to achieve the purpose of active balancing. At the same time, the second lamp G2 and the first lamp G1 can be connected through the BLAS pins of the first chip U1 and the second chip U2 to monitor whether the balancing mode is turned on.

[0048] In summary, this design uses a balancing circuit to charge the battery with a high voltage through an inductor, and turns on and off the MOS tubes inside the two chips to realize the transfer of charge, thereby achieving the purpose of balancing. This design has low power consumption and can also be used for multi-unit stacking. It periodically scans and detects the battery voltage and enters a sleep state when balancing is not required.

[0049] Example 3

[0050] Reference Figure 4 , which is the third embodiment of the utility model, includes all the contents of the first two embodiments, and also includes a protection circuit 200 including n voltage-stabilizing diodes 201 and n freewheeling diodes 202, the n voltage-stabilizing diodes 201 are connected in series, both ends of each voltage-stabilizing diode 201 are connected to the positive and negative poles of the battery, the n freewheeling diodes 202 are also connected in series, and each freewheeling diode 202 is also connected to the positive and negative poles of the battery;

[0051] Wherein, n is a natural number greater than or equal to 1. In the figure, 4 voltage zener diodes 201 are included, and both ends of each voltage zener diode 201 lead out a wiring harness connected between the positive and negative poles of the balancing circuit 100 and the battery to prevent abnormal connection of a certain battery cell and protect the voltage output of the chip pin of the balancing circuit from exceeding the rated voltage range to cause chip damage. A freewheeling diode 202 is also connected in parallel at both ends of each voltage zener diode 201 to prevent the current on the inductor from breaking through the chip due to abnormal connection of the battery cell when plugging and unplugging. The current can be consumed by the freewheeling diode 202 to play a protective role.

[0052] Normally, a high-voltage battery pack contains 30 battery cells, each of which requires a Zener diode 201 to protect the circuit. The four Zener diodes 201 in the figure are only part of the protection circuit 200 and are used to illustrate the principle and function of the protection circuit 200.

[0053] In summary, by setting a protection loop between the battery and the balancing circuit, not only can the voltage drop that damages the chip be prevented during the balancing process, but also the abnormal current that breaks down the chip during inductor charging can be prevented, thereby protecting the balancing circuit.

[0054] Importantly, it should be noted that the construction and arrangement of the present application shown in a number of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, changes in orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature or number or position of the discrete element may be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present utility model. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also an equivalent structure. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to a specific embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0055] Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment may not be described (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those features that are not relevant to implementing the invention).

[0056] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. An active equalization circuit for a high voltage energy storage battery, characterized in that: include, A battery pack (B) comprising a first battery (B1) and a second battery (B2), wherein the first battery (B1) and the second battery (B2) are connected in series; A balancing circuit (100) comprises a first balancing circuit (101) and a second balancing circuit (102), wherein the first balancing circuit (101) is connected to the positive and negative electrodes of a first battery (B1), and the second balancing circuit (102) is connected to the positive and negative electrodes of a second battery (B2); A protection circuit (200) is provided between the equalization circuit (100) and the battery pack (B).

2. The active equalization circuit for a high voltage energy storage battery according to claim 1, characterized in that: The first balancing circuit (101) comprises a first chip (U1), a BATP pin of the first chip (U1) being connected to the positive electrode of a first battery (B1), a BLAS pin being connected to the SW pin via a seventh capacitor (C7), a BATC pin being connected to the ISET pin via a fifth capacitor (C5) and a sixth capacitor (C6), and a third resistor (R3) being connected in parallel across both ends of the sixth capacitor (C6).

3. The active equalization circuit for a high voltage energy storage battery as claimed in claim 2, characterized in that: The SW pin of the first chip (U1) is also connected to a second inductor (L2).

4. The active equalization circuit for a high-voltage energy storage battery as claimed in claim 3, characterized in that: An eighth capacitor (C8) is also provided between the BATP pin and the SW pin of the first chip (U1).

5. The active equalization circuit for a high voltage energy storage battery as claimed in claim 4, characterized in that: The second balancing circuit (102) comprises a second chip (U2), wherein a BATP pin of the second chip (U2) is connected to a positive electrode of a second battery (B2), a BLAS pin is connected to a SW pin via a third capacitor (C3), a BATN pin is connected to a negative electrode of the second battery (B2), a second capacitor (C2) is arranged between the BATN pin and the ISET pin, and a first resistor (R1) is connected in parallel at both ends of the second capacitor (C2).

6. The active equalization circuit for a high-voltage energy storage battery as claimed in claim 5, characterized in that: The SW pin of the second chip (U2) is also connected to the first inductor (L1).

7. The active equalization circuit for a high-voltage energy storage battery according to claim 6, characterized in that: A first capacitor (C1) and a fourth capacitor (C4) are also provided between the BATN pin of the second chip (U2) and the BATC pin of the first chip (U1).

8. The active equalization circuit for a high-voltage energy storage battery according to claim 7, characterized in that: The two ends of the third capacitor (C3) are also connected in parallel with a second resistor (R2) and a first lamp (G1).

9. The active equalization circuit for a high-voltage energy storage battery as claimed in claim 8, characterized in that: The second ends of the seventh capacitor (C7) are also connected in parallel with a fourth resistor (R4) and a second lamp tube (G2).

10. The active equalization circuit for a high voltage energy storage battery according to claim 9, characterized in that: The protection circuit (200) comprises n voltage-stabilizing diodes (201) and n freewheeling diodes (202), the n voltage-stabilizing diodes (201) are connected in series, both ends of each voltage-stabilizing diode (201) are connected to the positive and negative electrodes of the battery through a wiring harness, the n freewheeling diodes (202) are also connected in series, and each freewheeling diode (202) is also connected to the positive and negative electrodes of the battery; Here, n is a natural number greater than or equal to 1.

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