A composite power supply module and composite power supply balancing system

Abstract

The present invention discloses a composite power supply module and a composite power supply balancing system. The composite power supply balancing system includes a battery management module, a capacitor management module, a balancing control module and a composite power supply module. The composite power supply module includes: a balancing circuit, a battery module and a capacitor module, the battery module and the capacitor module are connected in parallel; the battery module includes battery cells connected in series, the capacitor module includes capacitor cells connected in series, and the balancing circuit includes: a bidirectional DC / DC converter and / or a balancing switch pair (including a positive balancing switch and a negative balancing switch); the positive electrodes of the battery cells and the capacitor cells are connected to the first balancing current line through the positive electrodes or positive balancing switches of the corresponding bidirectional DC / DC converters, and the negative electrodes of the battery cells and the capacitor cells are connected to the second balancing current line through the negative electrodes or negative balancing switches of the corresponding bidirectional DC / DC converters. The present invention realizes the balancing of the voltages of each power supply unit in the composite power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of composite power supplies, and in particular to a composite power supply module and a composite power supply balancing system. Background Art

[0002] Electrochemical energy storage technology has the advantages of being intelligent, mobile, convenient, efficient, and green, and is widely used in portable electronic products, power tools, electric vehicles, electric boats, rail transit, aerospace, power energy storage, military equipment, and other fields. As a typical electrochemical energy storage technology, lithium-ion batteries have the advantages of high energy density (100-300Wh / kg), high efficiency, low self-discharge rate, and green environmental protection, and are highly favored by the industry. However, the power characteristics of lithium-ion batteries (power density ≤ 1kW / kg) are difficult to meet the requirements in many fields, such as rail transit and electric vehicle braking energy feedback, renewable energy grid-connected energy storage systems, and other fields (these fields need to meet high power output while meeting energy storage capacity requirements, otherwise more installed capacity needs to be matched to meet output power requirements). Obviously, a single lithium-ion battery energy storage technology is difficult to meet the requirements. In addition, lithium-ion batteries have a short cycle life, poor low-temperature characteristics, and serious safety issues under high-rate, full-charge and discharge conditions. In order to solve the drawbacks of lithium-ion batteries as a single energy storage technology, they are usually combined with electrochemical capacitors with ultra-high power density (≥1kW / kg), long cycle life (≥100,000 times), and wide temperature range (-40~70℃) to form a hybrid energy storage system to make up for the shortcomings of lithium-ion batteries, effectively extend the service life of lithium-ion batteries, and improve the output power of the energy storage system.

[0003] However, since it is difficult to ensure that the performance of lithium-ion batteries and electrochemical capacitors is completely consistent during the production process, when used in series and parallel, their differences will become increasingly severe during the cyclic charge and discharge process, affecting the working performance and cycle life of lithium-ion battery packs and electrochemical capacitor packs. Summary of the invention

[0004] The object of the present invention is to provide a composite power supply module and a composite power supply balancing system to achieve balancing of power supply voltages and residual charge amounts in the composite power supply module.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A composite power module comprises: an equalizing circuit, at least one battery module and at least one capacitor module, wherein the battery module and the capacitor module are connected in parallel;

[0007] The battery module comprises a plurality of battery cells connected in series, each of which comprises one or more battery cells connected in parallel, the capacitor module comprises a plurality of capacitor cells connected in series, each of which comprises one or more capacitor cells connected in parallel, and the balancing circuit comprises: a plurality of bidirectional DC / DC converters and / or a plurality of balancing switch pairs;

[0008] Each of the battery cells corresponds to a bidirectional DC / DC converter or a balancing switch pair, and each of the capacitor units corresponds to a bidirectional DC / DC converter or a balancing switch pair; each balancing switch pair corresponds to a battery cell or a capacitor unit, and each bidirectional DC / DC converter corresponds to a battery cell or a capacitor unit; the balancing switch pair includes a positive balancing switch and a negative balancing switch;

[0009] The positive electrode of each battery unit and the positive electrode of each capacitor unit are connected to the positive electrode on one side of the corresponding bidirectional DC / DC converter or one end of the corresponding positive electrode balancing switch, and the positive electrode on the other side of the bidirectional DC / DC converter and the other end of the positive electrode balancing switch are connected to the first balancing current line;

[0010] The negative electrode of each of the battery cells and the negative electrode of each of the capacitor units are connected to the negative electrode on one side of the corresponding bidirectional DC / DC converter or one end of the corresponding negative electrode balancing switch, and the negative electrode on the other side of the bidirectional DC / DC converter and the other end of the negative electrode balancing switch are connected to the second balancing current line.

[0011] Optionally, it also includes: a first variable resistor connected in series with the battery module, the first variable resistor being used to adjust the impedance of the battery module so that the operating voltage and the operating voltage of the battery module match the operating voltage and the operating voltage of the capacitor module.

[0012] Optionally, it also includes: a second variable resistor connected in series with the capacitor module, the second variable resistor being used to adjust the impedance of the capacitor module so that the operating voltage and the operating voltage of the capacitor module match the operating voltage and the operating voltage of the battery module.

[0013] Optionally, it also includes: a battery protection switch connected in series with the battery module.

[0014] Optionally, it also includes: a capacitor protection switch connected in series with the capacitor module.

[0015] Optionally, the method further includes: a first resistor and a first control switch, wherein the first balancing current line is connected to the second balancing current line through the first resistor and the first control switch.

[0016] The present invention also provides a composite power supply balancing system, comprising: a balancing control module and the composite power supply module;

[0017] The balancing control module controls the opening and closing of the bidirectional DC / DC converter, the balancing switch, the first control switch or the protection switch according to the voltage or the remaining charge of each battery unit and each capacitor unit.

[0018] Optionally, it also includes: a battery management module and a capacitor management module, the battery management module is used to collect the voltage and remaining charge of each battery unit, and the capacitor management module is used to collect the voltage and remaining charge of each capacitor unit.

[0019] According to the specific embodiment provided by the present invention, the following technical effects are disclosed: the composite power supply module provided by the embodiment of the present invention includes a balancing circuit, at least one battery module and at least one capacitor module. The battery module and the capacitor module are connected in parallel; the battery module includes a plurality of battery cells, the capacitor module includes a plurality of capacitor cells, and the balancing circuit includes a plurality of bidirectional DC / DC converters and / or a plurality of balancing switches. The positive electrode of each battery cell and the positive electrode of each capacitor cell are connected to the first balancing current line through a corresponding bidirectional DC / DC converter or a balancing switch, and the negative electrode of each battery cell and the negative electrode of each capacitor cell are connected to the second balancing current line through a corresponding bidirectional DC / DC converter or a balancing switch. In addition to the above-mentioned composite power supply module, the composite power supply balancing system provided by the embodiment of the present invention also includes a balancing control module, which controls the opening and closing of the bidirectional DC / DC converter or the balancing switch according to the voltage or residual charge of each battery cell and each capacitor cell.

[0020] By opening and closing the bidirectional DC / DC converter or the balancing switch, a power supply unit with a high voltage can charge a power supply unit with a low voltage, or a power supply unit with a large amount of energy storage can charge a power supply unit with a small amount of energy storage, thereby achieving a balance of energy storage module power. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 A schematic diagram of the structure of a composite power balancing system according to an embodiment of the present invention;

[0023] Figure 2FIG. 4 is another structural diagram of a composite power supply balancing system in an embodiment of the present invention.

[0024] 101——battery unit, 102——battery module, 103——battery management module, 104——battery bidirectional DC / DC conversion module, 105——battery protection switch, 106——first adjustable resistor, 201——capacitor unit, 202——capacitor module, 203——capacitor management module, 204——capacitor bidirectional DC / DC conversion module, 205——capacitor protection switch, 206——second adjustable resistor, 301——first balancing current line, 302——second balancing current line, 303——balancing circuit, 304——bidirectional DC / DC converter, 305——balancing control module, 306——balancing switch pair, 307——passive balancing resistor, 308——passive balancing control switch, 401——DC bus. DETAILED DESCRIPTION

[0025] In order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with basically the same functions and effects. For example, the first wireless communication module and the second wireless communication module are only used to distinguish different wireless communication modules, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order.

[0026] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0027] In the embodiment of the present invention, "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone. A and B can be single or multiple. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The object of the present invention is to provide a composite power supply module and a composite power supply balancing system to achieve balancing of power supply voltages and residual charge amounts in the composite power supply module.

[0030] The embodiment of the present invention provides a composite power module and a composite power balancing system. The composite power balancing system includes the composite power module and a balancing control module for controlling the composite power module.

[0031] The above composite power supply module is introduced in detail below.

[0032] See also Figure 1 and Figure 2 The composite power module includes: a balancing circuit 303, a battery module 102 and a capacitor module 202, and the battery module 102 and the capacitor module 202 are connected in parallel. In this embodiment, the number of the battery module 102 and the capacitor module 202 is one, and of course, in other embodiments, the number of the battery module 102 and the capacitor module 202 can be more than one.

[0033] The battery module 102 includes a plurality of battery units 101 connected in series, and each battery unit 101 is composed of one or more battery cells connected in parallel.

[0034] The capacitor module 202 includes a plurality of capacitor units 201 connected in series, and each capacitor unit 201 is composed of one or more capacitor monomers connected in parallel.

[0035] The balancing circuit 303 includes a plurality of bidirectional DC / DC converters 304 and / or a plurality of balancing switch pairs 306. The bidirectional DC / DC converters 304 and the balancing switch pairs 306 are used to balance the output voltages of the battery module 102 and the capacitor module 202, so as to enable a module with a high voltage to charge a module with a low voltage, or a module with a large amount of energy storage to charge a module with a small amount of energy storage, thereby achieving a balance of energy storage module power and meeting various working conditions and application requirements.

[0036] In this embodiment, each battery unit 101 uniquely corresponds to a bidirectional DC / DC converter 304 or uniquely corresponds to a balancing switch pair 306, and each capacitor unit 201 uniquely corresponds to a bidirectional DC / DC converter 304 or uniquely corresponds to a balancing switch pair 306. Each balancing switch pair 306 uniquely corresponds to a battery unit 101 or a capacitor unit 201, and each bidirectional DC / DC converter 304 uniquely corresponds to a battery unit 101 or a capacitor unit 201. The balancing switch pair 306 includes a positive balancing switch and a negative balancing switch.

[0037] The positive electrode of each of the battery cells 101 and the positive electrode of each of the capacitor units 201 are connected to the positive electrode on one side of the corresponding bidirectional DC / DC converter 304 or one end of the corresponding positive electrode balancing switch, and the positive electrode on the other side of the bidirectional DC / DC converter 304 and the other end of the positive electrode balancing switch are connected to the first balancing current line.

[0038] The negative electrode of each of the battery cells 101 and the negative electrode of each of the capacitor units 201 are connected to the negative electrode on one side of the corresponding bidirectional DC / DC converter 304 or one end of the corresponding negative electrode balancing switch, and the negative electrode on the other side of the bidirectional DC / DC converter 304 and the other end of the negative electrode balancing switch are connected to the second balancing current line.

[0039] The first balancing current line and the second balancing current line are used for energy transfer between the battery cells 101 and / or the capacitor cells 201 .

[0040] It should be noted that Figure 1 and Figure 2 The correspondence between the bidirectional DC / DC converter 304, the balancing switch pair 306, the battery unit 101, and the capacitor unit 201 is merely given as an example, that is, the composite power module only includes the balancing switch pair 306 but does not include the bidirectional DC / DC converter 304; or the composite power module only includes the bidirectional DC / DC converter 304 but does not include the balancing switch pair 306. In essence, the same composite power module may include both the bidirectional DC / DC converter 304 and the balancing switch pair 306.

[0041] See also Figure 1 and Figure 2 In this embodiment, the battery module 102 and the capacitor module 202 are connected in parallel to the DC bus 401. In other embodiments, the battery module 102 and the capacitor module 202 can also be connected in parallel to other power sources, loads or other composite power sources.

[0042] The battery unit 101 includes one or more of lithium ion battery, sodium ion battery, lead acid battery, flow battery, solid state battery, lithium sulfur battery, fuel cell. The capacitor unit 201 includes one or more of double layer capacitor, lithium ion capacitor, battery capacitor.

[0043] In one example, the composite power module further includes a first variable resistor 106 connected in series with the battery module 102 and a second variable resistor 206 connected in series with the capacitor module 202 .

[0044] The first variable resistor 106 is used to adjust the impedance of the battery module 102 so that the operating voltage and the working voltage of the battery module 102 match the operating voltage and the working voltage of the capacitor module 202 .

[0045] The second variable resistor 206 is used to adjust the impedance of the capacitor module 202 so that the operating voltage and the working voltage of the capacitor module 202 match the operating voltage and the working voltage of the battery module 102 .

[0046] In one example, the composite power module further includes a battery protection switch 105 connected in series with the battery module 102 and a capacitor protection switch 205 connected in series with the capacitor module 202 .

[0047] Specifically, the positive electrode of the battery module 102 is connected to the battery protection switch 105 or the first variable resistor 106, and the positive electrode of the capacitor module 202 is connected to the capacitor protection switch 205 or the second variable resistor 206. Alternatively, the negative electrode of the battery module 102 is connected to the battery protection switch 105 or the first variable resistor 106, and the negative electrode of the capacitor module 202 is connected to the capacitor protection switch 205 or the second variable resistor 206.

[0048] In the case of overcharge, overdischarge, overcurrent, or failure of the battery module 102, or overcharge, overdischarge, overcurrent, or failure of a certain battery unit 101, the battery protection switch 105 is disconnected, or the composite power module stops working, the battery protection switch 105 is disconnected. In the case of overcharge, overdischarge, overcurrent, or failure of the capacitor module 202, or overcharge, overdischarge, overcurrent, or failure of a certain capacitor unit 201, the capacitor protection switch 205 is disconnected, or the composite power stops working, the capacitor protection switch 205 is disconnected.

[0049] In one example, the number of battery cells 101 in the battery module 102 is n, and the battery cell voltage is U b , the total voltage of the battery module 102 is n×U b , the number of the battery module side balancing switch pairs 306 is 2n, where n is a natural number greater than or equal to 1. The number of capacitor units 201 in the capacitor module 202 is m, and the capacitor cell voltage is U b , the total voltage of the capacitor module 202 is m×U b , the number of capacitor module side balancing switches 306 is 2m, where m is a natural number greater than or equal to 1. Preferably, n×U b ≥m×U b .

[0050] In one example, for some extreme situations, such as when only the voltage or remaining charge of individual battery cells 101 or capacitor cells 201 is high and the voltages or remaining charge of the other battery cells 101 or capacitor cells 201 are balanced, a component is provided for consuming the excess charge of the above-mentioned individual battery cells 101 or capacitor cells 201.

[0051] Specifically, the above-mentioned components can be a passive balancing resistor 307 and a passive balancing control switch 308 arranged between the first balancing current line and the second balancing current line, and the first balancing current line is connected to the second balancing current line through the passive balancing resistor and the passive balancing control switch. The passive balancing switch is controlled to be opened and closed by the balancing control module.

[0052] In one example, see Figure 1 and Figure 2 The composite power supply module further includes: a battery bidirectional DC / DC conversion module 104 and a capacitor bidirectional DC / DC conversion module 204 .

[0053] The positive and negative electrodes on one side of the battery bidirectional DC / DC conversion module 104 are electrically connected to the positive and negative electrodes of the battery module respectively, and the positive and negative electrodes on the other side of the battery bidirectional DC / DC conversion module 104 are electrically connected to the positive and negative electrodes of the DC bus respectively.

[0054] The positive and negative electrodes on one side of the capacitor bidirectional DC / DC conversion module 204 are electrically connected to the positive and negative electrodes of the capacitor module respectively, and the positive and negative electrodes on the other side of the capacitor bidirectional DC / DC conversion module 204 are electrically connected to the positive and negative electrodes of the DC bus respectively.

[0055] The functions of the battery bidirectional DC / DC conversion module 104 and the capacitor bidirectional DC / DC conversion module 204 mainly include: (1) controlling the direct energy conversion between the battery module and the capacitor module; (2) the voltage of the battery module and the voltage of the capacitor module can be kept consistent through the DC / DC conversion module, thereby avoiding the current backflow between the battery module and the capacitor module due to the direct voltage difference between the battery module and the capacitor module, that is, the current flows from the module with high voltage to the module with low voltage.

[0056] Preferably, the battery bidirectional DC / DC conversion module 104 and the capacitor bidirectional DC / DC conversion module 204 are controlled by a balancing control module to be turned on, turned off, and have their conversion direction, etc. controlled.

[0057] The following is an introduction to the composite power balancing system.

[0058] The composite power supply balancing system provided in this embodiment includes: a battery management module 103, a capacitor management module 203, a balancing control module 305 and the composite power supply module. The battery management module 103 is used to collect the voltage and the remaining charge of each battery unit, and the capacitor management module 203 is used to collect the voltage and the remaining charge of each capacitor unit 201. The balancing control module 305 controls the opening and closing of the bidirectional DC / DC converter or the balancing switch pair 306 according to the voltage or the remaining charge of each battery unit and each capacitor unit 201.

[0059] In this embodiment, the battery management module 103 is mainly used for data collection of battery module current, temperature and voltage of each battery cell, estimation of remaining charge (SOC) of the battery module and / or battery cell, state of health evaluation (SOH), etc.

[0060] The capacitor management module 203 is mainly used for data collection of the capacitor module 202 current, temperature and voltage of each battery cell, estimation of the remaining charge (SOC) of the capacitor module 202 and / or the capacitor cell 201, and health evaluation (SOH).

[0061] The balancing control module 305 receives data information including voltage, current, temperature, SOC, SOH, etc. from the battery management module 103 and the capacitor management module 203, and controls the opening and closing of each bidirectional DC / DC converter, each balancing switch 306, the passive balancing control switch 308, the battery bidirectional DC / DC conversion module 104 and the capacitor bidirectional DC / DC conversion module 204 according to the received information.

[0062] The battery management module 103 includes a data acquisition unit, a communication unit and a central processing unit. The data acquisition unit can collect the total voltage of the battery module and the voltage of each battery cell. The communication unit can complete the communication with the equalization control module 305. The central processing unit is used to estimate the SOC and SOH of the battery cell and / or battery module.

[0063] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0064] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A composite power module, characterized in that: include: A balancing circuit, at least one battery module and at least one capacitor module, wherein the battery module and the capacitor module are connected in parallel; The battery module comprises a plurality of battery cells connected in series, each of which comprises one or more battery cells connected in parallel, the capacitor module comprises a plurality of capacitor cells connected in series, each of which comprises one or more capacitor cells connected in parallel, and the balancing circuit comprises: a plurality of bidirectional DC / DC converters and / or a plurality of balancing switch pairs; Each of the battery cells corresponds to a bidirectional DC / DC converter or a balancing switch pair, and each of the capacitor units corresponds to a bidirectional DC / DC converter or a balancing switch pair; each balancing switch pair corresponds to a battery cell or a capacitor unit, and each bidirectional DC / DC converter corresponds to a battery cell or a capacitor unit; the balancing switch pair includes a positive balancing switch and a negative balancing switch; The positive electrode of each battery unit and the positive electrode of each capacitor unit are connected to the positive electrode on one side of the corresponding bidirectional DC / DC converter or one end of the corresponding positive electrode balancing switch, and the positive electrode on the other side of the bidirectional DC / DC converter and the other end of the positive electrode balancing switch are connected to the first balancing current line; The negative electrode of each of the battery cells and the negative electrode of each of the capacitor units are connected to the negative electrode on one side of the corresponding bidirectional DC / DC converter or one end of the corresponding negative electrode balancing switch, and the negative electrode on the other side of the bidirectional DC / DC converter and the other end of the negative electrode balancing switch are connected to the second balancing current line; The composite power supply module further includes: a first resistor and a first control switch, and the first balancing current line is connected to the second balancing current line through the first resistor and the first control switch.

2. The composite power module according to claim 1, characterized in that: Also includes: A first variable resistor connected in series with the battery module, wherein the first variable resistor is used to adjust the impedance of the battery module so that the operating voltage of the battery module matches the operating voltage of the capacitor module.

3. The composite power module according to claim 1, characterized in that: Also includes: A second variable resistor connected in series with the capacitor module, wherein the second variable resistor is used to adjust the impedance of the capacitor module so that the operating voltage of the capacitor module matches the operating voltage of the battery module.

4. The composite power module according to claim 1, characterized in that: Also includes: A battery protection switch connected in series with the battery module.

5. The composite power module according to claim 1, characterized in that: Also includes: A capacitor protection switch connected in series with the capacitor module.

6. A composite power balancing system, characterized in that: include: A balancing control module and a composite power supply module as claimed in any one of claims 1 to 5; The balancing control module controls the opening and closing of the bidirectional DC / DC converter or the balancing switch according to the voltage or the remaining charge of each battery unit and each capacitor unit.

7. The composite power balancing system according to claim 6, characterized in that: Also includes: A battery management module and a capacitor management module, wherein the battery management module is used to collect the voltage and the remaining charge of each battery unit, and the capacitor management module is used to collect the voltage and the remaining charge of each capacitor unit.

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