Control method, circuit and equipment for balance charging based on multi-winding magnetic coupling

Abstract

The invention relates to the technical field of battery balance charging, and particularly discloses a control method, circuit and equipment for carrying out balance charging based on multi-winding magnetic coupling, the balance charging control circuit actively carries out active balance control on a balance circuit and a balance charging power conversion circuit by combining the detected electric quantity change condition of a battery pack; therefore, the balancing circuit and the balancing charging power conversion circuit perform balancing charging on the battery pack, so that each battery keeps relatively consistent dynamic voltage and dynamic SOC in the use process, the available capacity of the battery is improved, the service life of the battery is prolonged, the occurrence of a wooden barrel effect caused by series mismatch of the batteries is reduced, and the service life of the battery is prolonged. Or thermal runaway caused by circulation generated by parallel charging mismatch is reduced, the overall available capacity is further improved, the service life is prolonged, and the use safety and reliability of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery balance charging, and in particular to a control method, circuit and device for balance charging based on multi-winding magnetic coupling. Background Art

[0002] The current battery systems for household energy storage and industrial and commercial energy storage are composed of multiple PACKs connected in series and parallel in different ways to form the required voltage and capacity. Each PACK is composed of multiple batteries in series. According to different capacities and voltages, different numbers of PACKs will be connected in series to form a battery cluster, and then multiple battery clusters will form a container with a capacity of 100KW-several MW. From a small capacity of 5KWH to a large capacity of dozens of MWH, the number of battery cells is increasing, from dozens to hundreds, or even hundreds of thousands.

[0003] At present, the initial static balancing method is generally used for cell matching, that is, the ΔSOC capacity difference, ΔV voltage difference, and ΔR internal resistance difference between batteries are used for matching. However, in practice, it is found that this method cannot achieve accurate matching, and the life of each battery cell, self-discharge, internal gas production level (externally manifested as the pressure per unit area of ​​the module gradually increases), and the SOC internal resistance of the active material tend to be increasingly inconsistent after N cycles during use. Moreover, the passive balancing current currently used in large quantities is only a few hundred milliamperes. For charging and discharging currents of several amperes, tens of amperes, or even thousands of amperes during use, it is impossible to keep each battery cell in a relatively consistent dynamic voltage and dynamic SOC during use, resulting in a decrease in the available capacity of the entire battery cabinet and the entire battery cluster and a shortened life.

[0004] Therefore, it is particularly important to propose a technical solution for actively balancing the battery pack so that each battery cell maintains a relatively consistent dynamic voltage and dynamic SOC during use, thereby increasing the available capacity of the battery and extending the service life of the battery.

[0005] Invention data

[0006] The technical problem to be solved by the present invention is to provide a control circuit for balanced charging based on multi-winding magnetic coupling, which can actively balance the battery pack so that each battery cell maintains a relatively consistent dynamic voltage and dynamic SOC during use, thereby increasing the available capacity of the battery and extending the battery life.

[0007] In order to solve the above technical problems, the first aspect of the present invention discloses a control method for balanced charging based on multi-winding magnetic coupling, the method is applied to a control circuit, the control circuit includes a balanced charging power conversion circuit, an equalization circuit and a balanced charging control circuit, wherein:

[0008] The balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through a multi-winding magnetic coupling method, and the number of all the batteries is greater than or equal to 2; the controlled end of the balanced circuit is electrically connected to the second control end of the balanced charging control circuit, the direct charging end of the balanced circuit is used to electrically connect the battery pack, and the detection end of the balanced charging control circuit is used to electrically connect the battery pack, wherein:

[0009] The method comprises:

[0010] The balance charge control circuit detects the charge change of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the charge change of the battery pack, and performs a balance charge control operation on the battery pack.

[0011] As an optional implementation, in the first aspect of the present invention, the balancing circuit includes a charging state active balancing module and a direct charging module, wherein:

[0012] The switch end of the charging state active balancing module is electrically connected to the power supply end of the direct charging module, the controlled end of the direct charging module is electrically connected to the first sub-control end of the balance charging control circuit, and the direct charging end of the direct charging module is used to electrically connect to the battery pack;

[0013] The balancing end of the charging state active balancing module is electrically connected to the balancing end of the balanced charging power conversion circuit, and the controlled end of the charging state active balancing module is electrically connected to the second sub-control end of the balanced charging control circuit;

[0014] Among them, the first sub-control end of the balanced charging control circuit and the second sub-control end of the balanced charging control circuit constitute the second control end of the balanced charging control circuit, the balancing end of the charging state active balancing module is the balancing end of the balancing circuit, and the direct charging end of the direct charging module is the direct charging end of the balancing circuit.

[0015] As an optional implementation, in the first aspect of the present invention, the balance charge control circuit detects the change in the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change in the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, including:

[0016] When the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets the predetermined first power condition, the balance charge control circuit generates a connection signal corresponding to the balance charge power conversion circuit, and performs a connection operation on the branch where the balance charge power conversion circuit is located according to the connection signal corresponding to the balance charge power conversion circuit, so that the balance charge power conversion circuit performs a balance charge operation on the battery pack with a preset current;

[0017] The balance charge control circuit generates a direct charge shutoff signal of the direct charge module, and stops the direct charge operation on the battery pack according to the direct charge shutoff signal of the direct charge module, and after detecting that the direct charge operation on the battery pack is stopped, generates a current increase signal of the balance charge power conversion circuit, and performs an increase operation on the charging current of the balance charge power conversion circuit according to the current increase signal of the balance charge power conversion circuit;

[0018] During the process of performing a balancing charging operation on the battery pack with the increased charging current of the balancing charging power conversion circuit, the balancing charging control circuit monitors the charge change of the battery pack to obtain a first charge change of the battery pack, and generates a first current reduction signal matching the first charge change of the battery pack based on the first charge change of the battery pack, and performs a reduction operation on the charging current of the balancing charging power conversion circuit based on the first current reduction signal until the voltage of each battery in the battery pack is greater than or equal to a preset voltage.

[0019] As an optional implementation, in the first aspect of the present invention, the balance charge control circuit detects the change in the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change in the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, further comprising:

[0020] When the current state of the battery pack is used to indicate that the power of the battery in the battery pack satisfies a predetermined second power condition, the balancing charge control circuit monitors the second power change of the battery pack, and determines whether the current condition of the battery pack satisfies the determined charging current reduction condition according to the second power change of the battery pack, wherein the charge stored in the battery pack corresponding to the second power condition is less than the charge stored in the battery pack corresponding to the first power condition;

[0021] When it is determined that the charging current reduction condition is met, the balanced charging control circuit generates a second current reduction signal for the balanced charging power conversion circuit, and performs a charging current reduction operation on the balanced charging power conversion circuit according to the second current reduction signal;

[0022] The balance charge control circuit generates a direct charge connection signal of the direct charge module, and connects the direct charge terminal of the direct charge module to the battery pack according to the direct charge connection signal of the direct charge module, so as to perform a direct charge operation on the battery pack;

[0023] The balance charging control circuit generates a shutdown signal corresponding to the balance charging power conversion circuit, and shuts down the balance charging operation of the battery pack according to the shutdown signal corresponding to the balance charging power conversion circuit, and triggers the execution of the operation of generating a corresponding turn-on signal of the balance charging power conversion circuit when the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets the predetermined first power condition.

[0024] As an optional implementation, in the first aspect of the present invention, the balance charge control circuit detects the change in the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change in the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, further comprising:

[0025] When the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets a predetermined third power condition, the balance charge control circuit generates a connection signal of the equalization circuit and a first charging signal of the balance charge power conversion circuit, wherein the charge stored in the battery pack corresponding to the third power condition is less than the charge stored in the battery pack corresponding to the second power condition;

[0026] The balance charge control circuit controls the balance circuit to turn on the balance charge power conversion circuit according to the turn-on signal of the balance circuit, and controls the balance charge power conversion circuit to perform a charging operation on the battery pack with a first charging current matching the first charging signal according to the first charging signal of the balance charge power conversion circuit;

[0027] The balancing charge control circuit detects a third charge change of the battery pack, and generates a second charging signal for the balancing charge power conversion circuit according to the third charge change of the battery pack, and increases the charging current of the balancing charge power conversion circuit according to the second charging signal, and triggers the execution of the operation of monitoring the second charge change of the battery pack when the current state of the battery pack is used to indicate that the charge of the battery in the battery pack meets the predetermined second charge condition.

[0028] As an optional embodiment, in the first aspect of the present invention, the method further comprises:

[0029] The balance charge control circuit determines whether the direct charge terminal of the direct charge module is disconnected from the battery pack, and when the determination result is yes, triggers the execution of the operation of detecting the third power change of the battery pack;

[0030] When the result is judged to be negative, the balance charging control circuit generates a first shutdown signal, and according to the first shutdown signal, disconnects the connection between the direct charging end of the direct charging module and the battery pack, and triggers the operation of detecting the third charge change of the battery pack.

[0031] As an optional embodiment, in the first aspect of the present invention, the method further comprises:

[0032] In the process of charging the battery pack based on the balanced charging power conversion circuit, the balanced charging control circuit detects the first voltage change of each battery in the battery pack, and determines the voltage change type corresponding to the battery pack according to the first voltage change of each battery;

[0033] When the voltage change type corresponding to the battery pack is used to indicate that there is a first target battery in the battery pack whose voltage change meets a predetermined first current regulation condition, the balancing charge control circuit generates a first current control signal matching the voltage change of the first target battery, and performs a reduction operation on the current charging current of the battery pack according to the first current control signal corresponding to the first target battery; after charging the first target battery with the reduced current charging current of the first target battery, when it is determined that the current voltage change of the first target battery meets a predetermined second current regulation condition, generates a second current control signal matching the voltage change of the first target battery, and performs an increase operation on the current charging current of the battery pack according to the second current control signal corresponding to the first target battery;

[0034] When the voltage change type corresponding to the battery pack is used to indicate that the voltage change conditions of all batteries in the battery pack meet a predetermined second current regulation condition, the balancing charge control circuit generates a duty cycle control signal that matches the voltage change conditions corresponding to the battery pack, and according to the duty cycle control signal, performs a pulse width duty cycle reduction operation on the primary side corresponding to the balancing charge power conversion circuit to reduce the current charging current of the battery pack.

[0035] As an optional implementation, in the first aspect of the present invention, when the battery pack is in a discharging state, the balancing circuit includes a discharging state active balancing module, wherein the balancing end of the discharging state active balancing module is electrically connected to the balancing end of the balanced charging power conversion circuit, and the charging end of the discharging state active balancing module is used to electrically connect the battery pack; wherein the balancing end of the discharging state active balancing module is the balancing end of the balancing circuit, and the charging end of the discharging state active balancing module is the direct charging end of the balancing circuit;

[0036] The balance charge control circuit detects the change of the battery power in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the battery power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, including:

[0037] When it is determined that there is a second target battery whose current voltage is less than or equal to a predetermined voltage threshold or whose current voltage change rate is greater than or equal to a predetermined voltage change threshold during the discharge process of the battery pack, the balance charge control circuit generates a discharge equalization signal corresponding to the second target battery and a shutdown signal corresponding to each remaining battery in the battery pack except the second target battery, and performs an opening operation on the discharge state active equalization module according to the discharge equalization signal, so that the discharge state active equalization module is connected to the balance charge power conversion circuit, and at the same time, according to the shutdown signal corresponding to each remaining battery, disconnects the charging branch of the remaining battery;

[0038] During the process of performing balance charging on the second target battery, when it is monitored that the difference between the voltage of the second target battery and the average voltage of all the remaining batteries is less than or equal to a preset voltage difference, the balance charging control circuit generates a shutdown signal corresponding to the second target battery, and according to the shutdown signal corresponding to the second target battery, disconnects the charging branch of the second target battery, and re-executes the operation of determining whether there is a second target battery whose current voltage is less than or equal to a predetermined voltage threshold or whose current voltage change rate is greater than or equal to a predetermined voltage change threshold during the discharge process of the battery pack.

[0039] The second aspect of the present invention discloses a control circuit for balanced charging based on multi-winding magnetic coupling, the control circuit comprising a balanced charging power conversion circuit, an equalization circuit and a balanced charging control circuit, wherein:

[0040] The balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, and the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through multi-winding magnetic coupling, and the number of all the batteries is greater than or equal to 2;

[0041] The controlled end of the balancing circuit is electrically connected to the second control end of the balancing charge control circuit, the direct charging end of the balancing circuit is used to electrically connect to the battery pack, and the detection end of the balancing charge control circuit is used to electrically connect to the battery pack;

[0042] The balance charge control circuit is used to detect the charge change of the battery in the battery pack, and control the equalization circuit and the balance charge power conversion circuit according to the charge change of the battery pack, so as to perform balance charge control operation on the battery pack.

[0043] The third aspect of the present invention discloses a balanced charging control device, which includes a device body and a control circuit in a control method for balanced charging based on multi-winding magnetic coupling as described in any one of the first aspects, and the device body is used to place the control circuit, and the balanced charging control device is used to execute any one of the control methods for balanced charging based on multi-winding magnetic coupling as described in the first aspect.

[0044] The implementation of the present invention has the following beneficial effects:

[0045] In the present invention, a control method for balanced charging based on multi-winding magnetic coupling is provided, and the method is applied to a control circuit, and the control circuit includes a balanced charging power conversion circuit, a balancing circuit and a balanced charging control circuit, wherein the balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, and the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, and the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through multi-winding magnetic coupling, and the number of all batteries is greater than or equal to 2; the controlled end of the balancing circuit is electrically connected to the second control end of the balanced charging control circuit, the direct charging end of the balancing circuit is used to electrically connect the battery pack, and the detection end of the balanced charging control circuit is used to electrically connect the battery pack, wherein the method includes: the balanced charging control circuit detects the change in the charge of the battery in the battery pack, and controls the balancing circuit and the balanced charging power conversion circuit according to the corresponding change in the charge of the battery pack, and performs a balanced charging control operation on the battery pack. It can be seen that the balanced charging control circuit of the present invention actively performs balanced control on the balancing circuit and the balanced charging power conversion circuit by combining the detected changes in the power of the battery pack, so that the balancing circuit and the balanced charging power conversion circuit perform balanced charging on the battery pack, so that each battery cell maintains a relatively consistent dynamic voltage and dynamic SOC during use, thereby improving the available capacity of the battery and extending the battery life, and reducing the occurrence of the barrel effect caused by battery series mismatch, reducing the occurrence of circulating current causing thermal runaway caused by parallel mismatch, further improving the overall available capacity and extending the service life, and improving the safety and reliability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 work.

[0047] Figure 1 It is a structural schematic diagram of a control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention;

[0048] Figure 2 It is a flow chart of a control method for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention;

[0049] Figure 3 It is a structural schematic diagram of another control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention;

[0050] Figure 4It is a structural schematic diagram of another control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention;

[0051] Figure 5 A schematic structural diagram of another control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention;

[0052] Figure 6 It is a structural schematic diagram of a balanced charging control device disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0054] It should be noted that, unless otherwise clearly specified and limited, the term "electrical connection" in the specification and claims of the present invention and the above-mentioned drawings should be understood in a broad sense. For example, it can be a fixed electrical connection, a detachable electrical connection, or an integral electrical connection; it can be a mechanical electrical connection, an electrical electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. In addition, the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. The terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] Embodiment 1

[0056] See also Figure 1-2 , Figure 1 is a structural schematic diagram of a control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention, Figure 2 is a flow chart of a control method for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention, Figure 2 The method is applied in Figure 1 In the control circuit, the method and circuit are applicable to one of the batteries such as sodium ion battery, ternary lithium battery, lithium iron phosphate battery, etc. Figure 1 As shown, the control circuit includes a balanced charging power conversion circuit, a balancing circuit and a balanced charging control circuit, wherein:

[0057] The balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through a multi-winding magnetic coupling method, and the number of batteries in the battery pack is greater than or equal to 2; the controlled end of the balancing circuit is electrically connected to the second control end of the balanced charging control circuit, the direct charging end of the balancing circuit is used to electrically connect to the battery pack, and the detection end of the balanced charging control circuit is used to electrically connect to the battery pack.

[0058] like Figure 2 As shown, the control method for balanced charging based on multi-winding magnetic coupling may include the following steps:

[0059] 101. The balance charge control circuit detects the change in the charge level of the batteries in the battery pack.

[0060] 102. The balance charge control circuit controls the equalization circuit and the balance charge power conversion circuit according to the corresponding power change of the battery pack, and performs a balance charge control operation on the battery pack.

[0061] It can be seen that implementation Figure 2 In the described method, the balancing charge control circuit actively performs balancing control on the balancing circuit and the balancing charge power conversion circuit by combining the detected charge change of the battery pack, so that the balancing circuit and the balancing charge power conversion circuit perform balanced charging on the battery pack, so that each battery cell maintains a relatively consistent dynamic voltage and dynamic SOC during use, thereby improving the available capacity of the battery and extending the battery life, and reducing the occurrence of the barrel effect caused by battery series mismatch, or reducing the occurrence of circulating current causing thermal runaway caused by battery parallel charging mismatch, further improving the overall available capacity and extending the service life, and improving the safety and reliability of the battery.

[0062] In the embodiment of the present invention, optionally, Figure 3 As shown, Figure 3 FIG. 1 is a schematic diagram of another control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention. Figure 3 As shown, the equalization circuit includes a charging state active equalization module and a direct charging module, wherein:

[0063] The switch end of the active charging balancing module is electrically connected to the power supply end of the direct charging module, the controlled end of the direct charging module is electrically connected to the first sub-control end of the balance charging control circuit, and the direct charging end of the direct charging module is used to electrically connect the battery pack, such as Figure 3 As shown, a battery pack consisting of two batteries is used for illustration, specifically, it is used to electrically connect the batteries at the end points of the battery pack;

[0064] The balancing end of the active balancing module in the charging state is electrically connected to the balancing end of the balanced charging power conversion circuit, and the controlled end of the active balancing module in the charging state is electrically connected to the second sub-control end of the balanced charging control circuit;

[0065] Among them, the first sub-control end of the balanced charging control circuit and the second sub-control end of the balanced charging control circuit constitute the second control end of the balanced charging control circuit, the balancing end of the charging state active balancing module is the balancing end of the balancing circuit, and the direct charging end of the direct charging module is the direct charging end of the balancing circuit.

[0066] In an embodiment of the present invention, the direct charging module may include a direct charging switch and a direct charging power conversion module, wherein the direct charging switch may be integrated on the direct charging power conversion module or may be independent of the direct charging power conversion module. When independent of the direct charging power conversion module, the controlled end of the direct charging power conversion module and the controlled end of the direct charging switch are respectively electrically connected to the sub-control end and another sub-control end of the balancing charging control circuit, wherein the sub-control end and another sub-control end of the balancing charging control circuit constitute the first sub-control end of the balancing charging control circuit, and the power supply end of the direct charging power conversion module is electrically connected to the switch end of the charging state active balancing module and the switch end of the direct charging switch at the same time, and the direct charging end of the direct charging switch is used to electrically connect the battery pack, specifically, to electrically connect the battery at the end point in the battery pack. The direct charging power conversion module is used to provide a power source VIN for balancing and direct charging of the battery.

[0067] In the embodiment of the present invention, optionally, Figure 4 As shown, Figure 4 is a structural schematic diagram of another control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention, such as Figure 4 As shown, the balancing circuit includes an active balancing module in a discharge state, wherein the balancing end of the active balancing module in a discharge state is electrically connected to the balancing end of the balanced charging power conversion circuit, and the charging end of the active balancing module in a discharge state is used to electrically connect to the battery pack; wherein the balancing end of the active balancing module in a discharge state is the balancing end of the balancing circuit, and the charging end of the active balancing module in a discharge state is the direct charging end of the balancing circuit.

[0068] In the embodiment of the present invention, further optional, such as Figure 3 and Figure 4As shown, the control circuit also includes a rectifier control switch circuit and a multi-winding magnetic coupling transformer, wherein the multi-winding magnetic coupling transformer is composed of a primary side coil and a plurality of secondary side coils, and further, an iron core is arranged between the primary side coil and all the secondary side coils. The rectifier control switch circuit is composed of a plurality of rectifier control switch modules, and the number of all rectifier control switch modules is equal to the number of secondary side coils and equal to the number of all batteries in the battery, and each rectifier control switch module has a unique corresponding battery and secondary side coil, wherein, for any rectifier control switch module, the charging end of the balanced charging power conversion circuit is coupled to the secondary side coil corresponding to the rectifier control switch module through the primary side coil of the multi-winding magnetic coupling transformer, the controlled end of the rectifier control switch module is electrically connected to the third control end of the balanced charging control circuit, and the control end of the rectifier control switch module is used to electrically connect the battery corresponding to the rectifier control switch module.

[0069] In the embodiment of the present invention, optionally, when the battery pack is in a discharging state, the balance charge control circuit detects the charge change of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the charge change corresponding to the battery pack, and performs a balance charge control operation on the battery pack, including:

[0070] When the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets the predetermined first power condition, the balance charge control circuit generates a connection signal corresponding to the balance charge power conversion circuit, and performs a connection operation on the branch where the balance charge power conversion circuit is located according to the connection signal corresponding to the balance charge power conversion circuit, so that the balance charge power conversion circuit performs a balance charge operation on the battery pack with a preset current;

[0071] The balance charge control circuit generates a direct charge shutoff signal of the direct charge module, and stops the direct charge operation on the battery pack according to the direct charge shutoff signal of the direct charge module. After detecting that the direct charge operation on the battery pack is stopped, a current increase signal of the balance charge power conversion circuit is generated, and the charging current of the balance charge power conversion circuit is increased according to the current increase signal of the balance charge power conversion circuit.

[0072] During the process of performing a balancing charging operation on the battery pack with the increased charging current of the balancing charging power conversion circuit, the balancing charging control circuit monitors the charge change of the battery pack to obtain a first charge change of the battery pack, and generates a first current reduction signal that matches the first charge change of the battery pack based on the first charge change of the battery pack, and performs a reduction operation on the charging current of the balancing charging power conversion circuit based on the first current reduction signal until the voltage of each battery in the battery pack is greater than or equal to a preset voltage.

[0073] In an embodiment of the present invention, optionally, a balancing charge control circuit detects changes in the charge level of batteries in a battery pack (such as changes in charge). When the charge level change is used to indicate that the current charge of the battery pack is within a predetermined first range of charge (such as 85%-90% of the full charge of the battery pack) and / or the voltage of each battery in the battery pack is stable within a predetermined first voltage range (such as 3.3V-3.5V, taking lithium iron phosphate batteries as an example), it indicates that the charge level of the batteries in the battery pack satisfies a predetermined first charge condition. At this point, it can be understood as any charge level in the full charge segment.

[0074] In an embodiment of the present invention, the charging state active balancing module is connected to the balanced charging power conversion circuit, indicating that the branch where the balanced charging power conversion circuit is located is connected. At this time, the battery pack can be charged with a small current (such as 5%-10% of the rated current), and the electrical connection between the direct charging module (more specifically, the direct charging switch) and the battery pack is cut off to stop direct charging. Then, the charging current of the balanced charging power conversion circuit is increased. If it reaches 30% of the rated current, the charge change of the battery pack is continuously monitored. Every time the voltage of each battery rises by a preset voltage (such as 5mV) or the voltage rising slope rises by a preset rising slope (such as 0.1), the charging current of the balanced charging power conversion circuit is reduced once until the voltage of all batteries is charged to a preset voltage, such as the voltage corresponding to 98% full charge.

[0075] It can be seen that if this optional embodiment detects that the battery pack has a large amount of power, it first selects a smaller balancing charging current, then turns off the direct charging, and then increases the balancing charging current, and then slowly decreases the current according to the change in the battery power, to ensure that the charged power does not cause a sharp rise in voltage, but instead maintains a stable and consistent slow rise in the voltage of each battery, further improving the consistency of the battery dynamic voltage and dynamic SOC.

[0076] In the embodiment of the present invention, further optionally, the balance charge control circuit detects the change of the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, further comprising:

[0077] When the current state of the battery pack is used to indicate that the power of the battery in the battery pack satisfies a predetermined second power condition, the balancing charge control circuit monitors the second power change of the battery pack, and determines whether the current condition of the battery pack satisfies the determined charging current reduction condition according to the second power change of the battery pack, wherein the charge stored in the battery pack corresponding to the second power condition is less than the charge stored in the battery pack corresponding to the first power condition;

[0078] When it is determined that the charging current reduction condition is met, the balance charge control circuit generates a second current reduction signal for the balance charge power conversion circuit, and performs a charging current reduction operation on the balance charge power conversion circuit according to the second current reduction signal;

[0079] The balance charge control circuit generates a direct charge connection signal of the direct charge module, and connects the direct charge terminal of the direct charge module to the battery pack according to the direct charge connection signal of the direct charge module, so as to perform a direct charge operation on the battery pack;

[0080] The balancing charging control circuit generates a shutdown signal corresponding to the balancing charging power conversion circuit, and shuts down the balancing charging operation of the battery pack according to the shutdown signal corresponding to the balancing charging power conversion circuit, and triggers the execution of the above-mentioned operation of generating a corresponding connection signal of the balancing charging power conversion circuit when the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets the predetermined first power condition.

[0081] In an embodiment of the present invention, optionally, a balancing charge control circuit detects changes in the charge level of batteries in the battery pack (such as changes in charge). When the charge level change is used to indicate that the current charge of the battery pack is within a predetermined second charge range (such as 15%-18% of the full charge of the battery pack) and / or the voltage of each battery in the battery pack is stable within a predetermined second voltage range (such as 3.18V-3.20V, taking lithium iron phosphate batteries as an example), it indicates that the charge level of the batteries in the battery pack satisfies the predetermined second charge level condition. At this time, it can be understood as any charge level of the capacity segment.

[0082] In an embodiment of the present invention, optionally, when the second charge change of the battery pack is used to indicate that the current charge of the battery pack is within a predetermined third charge range (such as 18%-23% of the full charge of the battery pack) and / or the voltage of each battery in the battery pack is stable within a predetermined third voltage range (such as 3.20V-3.21V, taking lithium iron phosphate battery as an example), it indicates that the charging current reduction condition is met, and according to the generated second current reduction signal, the charging current of the balancing charging power conversion circuit is reduced, such as reduced to 5%-10% of the rated current, and then the direct charging switch is turned on to perform direct charging operation on the battery pack, and the balancing charging power conversion circuit is turned off, wherein the balancing charging power conversion circuit can be turned off by turning off the active balancing module of the charging state or turning off the balancing charging power conversion module, that is, stopping charging the battery pack through the balancing charging power conversion circuit. It should be noted that, since this time it starts from a certain power state, when the battery pack is directly charged, the above-mentioned operation of generating a connection signal corresponding to the balanced charging power conversion circuit when the current state of the battery pack is used to indicate that the power of the batteries in the battery pack meets the predetermined first power condition can continue to be executed. It can be understood as a change from the capacity segment to the full charge segment, that is, continuing to execute the charging operation corresponding to the full charge segment.

[0083] It can be seen that in the embodiment of the present invention, when a certain amount of power is detected in the battery pack, the balancing charging current is first reduced and then the direct charging switch and the battery pack are turned on, that is, when the voltages of the batteries in the battery pack are basically equal, the battery pack is directly charged, and then the charging of the battery pack through the balancing charging power conversion module is turned off, thereby improving the consistency of the dynamic voltage and dynamic SOC of the battery and reducing the power consumption of the balancing charging power conversion circuit and the charging state active balancing module.

[0084] In the embodiment of the present invention, further, the balance charge control circuit detects the change of the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the power corresponding to the battery pack, and performs the balance charge control operation on the battery pack, and also includes:

[0085] When the current state of the battery pack is used to indicate that the charge of the battery in the battery pack meets a predetermined third charge condition, the balance charge control circuit generates a switch-on signal of the equalization circuit and a first charging signal of the balance charge power conversion circuit, wherein the charge stored in the battery pack corresponding to the third charge condition is less than the charge stored in the battery pack corresponding to the second charge condition;

[0086] The balance charge control circuit controls the balance circuit to turn on the balance charge power conversion circuit according to the turn-on signal of the balance circuit, and controls the balance charge power conversion circuit to perform a charging operation on the battery pack with a first charging current matching the first charging signal according to the first charging signal of the balance charge power conversion circuit;

[0087] The balancing charge control circuit detects the change in the third charge level of the battery pack, and generates a second charging signal for the balancing charge power conversion circuit according to the change in the third charge level of the battery pack, and increases the charging current of the balancing charge power conversion circuit according to the second charging signal, and triggers the execution of the above-mentioned operation of monitoring the change in the second charge level of the battery pack when the current state of the battery pack is used to indicate that the charge level of the batteries in the battery pack meets the predetermined second charge level condition.

[0088] In the embodiment of the present invention, optionally, the balance charge control circuit detects the charge change of the battery in the battery pack (such as the charge change). When the charge change is used to indicate that the current charge of the battery pack is in a predetermined fourth charge range (such as less than 0.5% of the full charge of the battery pack) and / or the voltage of each battery in the battery pack is stable in a predetermined fourth voltage range (such as 2.8V-2.9V, taking lithium iron phosphate battery as an example), it indicates that the charge of the battery in the battery pack meets the predetermined third charge condition. At this time, it can be understood as any charge condition in the power-deficient stage. The balance charge power conversion circuit and the charging state active equalization module are turned on to perform a charging operation on the battery pack with a first charging current (such as 5%-10% of the rated current).

[0089] In the embodiment of the present invention, optionally, when the third charge change of the battery pack is used to indicate that the current charge of the battery pack changes from one charge state to another charge state (such as from 1% to 5% to 20% of the full charge of the battery pack), the charging current of the balancing charging power conversion circuit is increased in sequence until the rated current is reached to charge the battery pack. It should be noted that since this is starting from a very low charge state, when the battery pack is charged with the rated current, the above-mentioned operation of monitoring the second charge change of the battery pack when the current state of the battery pack is used to indicate that the charge of the battery in the battery pack meets the predetermined second charge condition can continue to be performed, which can be understood as changing from the power-deficient segment to the capacity segment, that is, continuing to perform the charging operation corresponding to the capacity segment.

[0090] In the embodiment of the present invention, it should be noted that when the current state of the battery pack is used to indicate that the power level of the batteries in the battery pack meets the third power level condition determined in advance, or when the balanced charging power conversion circuit and the charging state active balancing module are turned on, if the discharge state active balancing module is in the process of being turned on, it is necessary to turn off the discharge state active balancing module at this time to prevent the battery pack from further discharging and further power loss, while improving the accuracy and reliability of balanced charging of the battery pack through the charging state active balancing module and the balanced charging power conversion circuit.

[0091] It can be seen that in the embodiment of the present invention, if it is detected that the power of the battery pack is very low, the battery pack is first charged with a small current through the charging state active balancing module and the balanced charging power conversion circuit, and the charging current is increased in sequence according to the change of the power of the battery pack to charge the battery pack in sequence, thereby further improving the accuracy and reliability of the balanced charging of the battery pack under low power conditions.

[0092] In an optional embodiment, the method may further include the following steps:

[0093] The balance charge control circuit determines whether the direct charge terminal of the direct charge module is disconnected from the battery pack, and when the determination result is yes, triggers the execution of the above-mentioned operation of detecting the third power change of the battery pack;

[0094] When the result is negative, the balance charge control circuit generates a first shutdown signal, and according to the first shutdown signal, disconnects the connection between the direct charging terminal of the direct charging module and the battery pack, and triggers the above-mentioned operation of detecting the third power change of the battery pack.

[0095] In this optional embodiment, during the process of the balanced charging power conversion circuit performing a charging operation on the battery pack with a first charging current matching the first charging signal, if the direct charging end of the direct charging switch has been disconnected from the battery pack, the battery pack continues to be charged through the charging status active balancing module; if the connection has not been disconnected, the connection is disconnected first, and then the battery pack is charged through the charging status active balancing module.

[0096] It can be seen that when the battery pack is in a low power state, if the direct charging branch of the battery pack is connected at this time, this optional embodiment is disconnected first, and switched to active balanced charging of the battery pack through the charging state active balancing module and the balanced charging power conversion circuit, thereby further improving the active balanced charging of the battery pack while improving the charging efficiency of the battery pack.

[0097] In another optional embodiment, the method may further include the following steps:

[0098] In the process of charging the battery pack based on the balanced charging power conversion circuit, the balanced charging control circuit detects the first voltage change of each battery in the battery pack, and determines the voltage change type corresponding to the battery pack according to the first voltage change of each battery;

[0099] When the voltage change type corresponding to the battery pack is used to indicate that there is a first target battery in the battery pack whose voltage change meets the predetermined first current regulation condition, the balancing charge control circuit generates a first current control signal matching the voltage change of the first target battery, and performs a reduction operation on the current charging current of the battery pack according to the first current control signal corresponding to the first target battery; after charging the first target battery with the current charging current of the reduced first target battery, when it is determined that the current voltage change of the first target battery meets the predetermined second current regulation condition, a second current control signal matching the current voltage change of the first target battery is generated, and performs an increase operation on the current charging current of the battery pack according to the second current control signal corresponding to the first target battery;

[0100] When the voltage change type corresponding to the battery pack is used to indicate that the voltage change of all batteries in the battery pack meets the predetermined second current regulation condition, the balancing charge control circuit generates a duty cycle control signal that matches the voltage change corresponding to the battery pack, and according to the duty cycle control signal, performs a pulse width duty cycle reduction operation on the primary side corresponding to the balancing charge power conversion circuit to reduce the current charging current of the battery pack.

[0101] In this optional embodiment, the balancing charge control circuit performs a reduction operation on the current charging current of the battery pack according to the first current control signal corresponding to the first target battery, including:

[0102] The balancing charge control circuit controls the rectifier control switch module corresponding to the first target battery to turn off according to the first current control signal corresponding to the first target battery, or performs a pulse width duty cycle reduction operation on the rectifier control switch module corresponding to the first target battery to reduce the current charging current of the first target battery;

[0103] And, the balancing charge control circuit performs an increase operation on the current charging current of the battery pack according to the second current control signal corresponding to the first target battery, including:

[0104] The balancing charge control circuit controls the rectifier control switch module corresponding to the first target battery to turn on according to the second current control signal corresponding to the first target battery, and / or performs a pulse width duty cycle increasing operation on the rectifier control switch module corresponding to the first target battery to increase the current charging current of the first target battery.

[0105] It should be noted that this optional embodiment may occur in the balancing charging process corresponding to the first power condition, the second power condition, the third power condition, or the intersection of the two conditions. The number of second target batteries may be 1, 2, or even other numbers, and the specific second target batteries and the corresponding numbers at different times may be the same or different, which is a dynamic transformation process.

[0106] In this optional embodiment, the first current regulation condition includes that the difference between the voltage and the voltage average of all other batteries in the battery pack at the current moment is less than or equal to a preset voltage difference, such as 10mV, or the voltage rising slope is greater than or equal to a preset rising slope, such as 2%. The second current regulation condition includes that the voltage rising slope of all batteries in the battery pack is greater than or equal to a preset rising slope.

[0107] In this optional embodiment, if the balanced charging control circuit is composed of a control chip MCU and a feedback loop, whether it is changing the duty cycle corresponding to the rectifier control switch module or changing the primary side duty cycle of the balanced charging power conversion circuit, the control change is performed through the feedback loop according to the corresponding current control signal.

[0108] In this optional embodiment, for the switch switching between the direct charging power conversion module and the balanced charging power conversion circuit, when the presence of the second target battery is detected, the battery pack is first charged through the balanced charging power conversion circuit based on a smaller preset current (such as 5%-10% of the rated current), and then the output current of the direct charging conversion power module is gradually reduced, and then the direct charging switch is turned off, and the battery pack is charged through the balanced charging power conversion circuit, and then the corresponding duty cycle is changed or the rectification control switch module is turned off. When the voltage of all batteries in the battery pack is the same, charging is performed based on a smaller preset current (such as 5%-10% of the rated current), and the direct charging switch is turned on to increase the direct charging current to the rated value for direct charging, and this cycle is repeated. During the entire charging process, the voltage of each section is dynamically maintained consistent.

[0109] It can be seen that this optional embodiment analyzes the voltage change of the batteries in the battery pack no matter which stage the battery pack is in. If the voltage of a battery cell is too large or rises too fast, charging is stopped or the duty cycle of the corresponding secondary-side rectifier control switch module is reduced, thereby reducing the average charging current of the circuit and making the voltage rise rate of the battery cell tend to be gentle and consistent with other cells. Conversely, charging is started or the duty cycle is increased to increase the average charging current of the circuit, so that it is consistent with other cells and the charging efficiency of the battery cell is improved. If the voltage of all batteries rises too fast, the duty cycle of the primary side is reduced to reduce the average charging current of all batteries, and the voltage rise rate tends to be gentle, so as to prevent the battery voltage from being too high. That is, the voltage and charging current of each battery cell are dynamically adjusted according to the different voltage conditions of the batteries in the battery pack, so that the voltage and power of each battery cell are as consistent as possible, and the battery will not be overcharged, and the primary or secondary overvoltage or overcharge protection will not be triggered.

[0110] In the embodiment of the present invention, when the battery pack is in a discharging state, the balance charge control circuit detects the change in the power of the battery in the battery pack, and controls the balance circuit and the balance charge power conversion circuit according to the change in the power of the battery pack, and performs a balance charge control operation on the battery pack, including:

[0111] When it is determined that there is a second target battery whose current voltage is less than or equal to a predetermined voltage threshold (such as 20mV) or whose current voltage change rate is greater than or equal to a predetermined voltage change threshold during the discharge process of the battery pack, the balance charge control circuit generates a discharge balance signal corresponding to the second target battery and a shutdown signal corresponding to each remaining battery in the battery pack except the second target battery, and performs an opening operation on the discharge state active balance module according to the discharge balance signal, so that the discharge state active balance module is connected to the balance charge power conversion circuit, and at the same time, according to the shutdown signal corresponding to each remaining battery, the charging branch of the remaining battery is disconnected;

[0112] During the process of performing balance charging on the second target battery, when it is monitored that the difference between the voltage of the second target battery and the average voltage of all remaining batteries is less than or equal to a preset voltage difference (such as 1mV), the balance charging control circuit generates a shutdown signal corresponding to the second target battery, and according to the shutdown signal corresponding to the second target battery, disconnects the charging branch of the second target battery, and re-determines whether there is a second target battery in the battery pack whose current voltage is less than or equal to a predetermined voltage threshold or whose current voltage change rate is greater than or equal to a predetermined voltage change threshold during the discharge process, and continues to execute the same process.

[0113] In this optional embodiment, during the discharge process, the external voltage drop rate of the battery with large internal resistance is relatively large, wherein the external voltage can be equivalent to the battery voltage minus the internal resistance voltage. Optionally, when it is detected that the direct charging switch is electrically connected to the battery pack or it is detected that the direct charging power conversion module, the charging state active balancing module and the branch where the balance charging control circuit is located are connected, it needs to be closed first. It should be noted that the charging state active balancing module is also the switch of the balance charging control circuit.

[0114] In this optional embodiment, specifically, according to the discharge balancing signal, the discharge state active balancing module is turned on to connect the discharge state active balancing module with the balanced charging power conversion circuit, and at the same time, according to the shutdown signal corresponding to each remaining battery, the charging branch of the remaining battery is disconnected, that is, the rectifier control switch module corresponding to the remaining battery is turned off, or the duty cycle of the corresponding rectifier switch control module is set to 0, so that the second target battery is charged during the discharge of the battery pack through the rectifier control switch module corresponding to the second target battery; according to the shutdown signal corresponding to the second target battery, the charging branch of the second target battery is disconnected, specifically, according to the shutdown signal corresponding to the second target battery, the rectifier control switch module corresponding to the second target battery is turned off, or the discharge state active balancing module is turned off, or the balanced charging power conversion circuit is turned off, or the duty cycle of the corresponding rectifier switch control module is set to 0, so as to stop charging the second target battery.

[0115] It should be noted that the discharge process and the charge process of the battery pack are convertible processes.

[0116] It can be seen that this optional embodiment monitors the voltage between batteries in the battery pack during the discharge process, and when inconsistency is detected, adjusts and controls the charging current and voltage in real time according to the inconsistency, and repeats this cycle to dynamically maintain the consistency of the voltage of each cell during the entire discharge process.

[0117] It should be noted that, regardless of whether it is dynamic active balancing charging or discharging, the more batteries that need to be charged at the same time, the greater the duty cycle of the primary side of the balancing charging power conversion circuit; if the number of batteries that need to be charged at the same time is smaller, the duty cycle of the primary side of the balancing charging power conversion circuit is smaller; and the charging voltage and charging current will be adjusted in real time according to the number of charging batteries, charging state / discharging state, different stages of the battery pack (such as low power stage, capacity stage, full power stage), changes in power at different time periods during the charging and discharging process of the battery pack, cycle life (such as calendar life, actual group working service life) and the internal resistance of the battery to achieve dynamic balancing charging of the battery pack.

[0118] Embodiment 2

[0119] A control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention is as follows: Figure 1 As shown, it includes a balanced charging power conversion circuit, a balancing circuit and a balanced charging control circuit, wherein:

[0120] The balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through a multi-winding magnetic coupling method, and the number of all batteries is greater than or equal to 2; the controlled end of the balancing circuit is electrically connected to the second control end of the balanced charging control circuit, the direct charging end of the balancing circuit is used to electrically connect the battery pack, and the detection end of the balanced charging control circuit is used to electrically connect the battery pack, wherein:

[0121] The balance charge control circuit is used to detect the charge change of the battery in the battery pack, and control the equalization circuit and the balance charge power conversion circuit according to the corresponding charge change of the battery pack to perform balance charge control operations on the battery pack.

[0122] In the embodiment of the present invention, Figure 5 A structural diagram of another control circuit for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention is shown in FIG. Figure 5 As shown, the balance charge control circuit can be a control chip MCU, and can also include a feedback loop, wherein, Figure 5As shown, the communication end of the control chip MCU is electrically connected to the communication end of the feedback loop, the first feedback end and the second feedback end of the feedback loop are electrically connected to the controlled end of the balanced charging power conversion circuit respectively, and the ground end of the feedback loop and the ground end of the balanced charging power conversion circuit are both used for grounding. Among them, the feedback loop can specifically be a circuit using an optocoupler or an isolation amplifier as an isolation method. Furthermore, current detection can be achieved by measuring the voltage across the sampling resistor Rs. Taking four batteries connected in series BTAT1, BTAT2, BTAT3, and BTAT4 as an example, the power stages corresponding to the first power condition, the second power condition, and the third power condition are defined as a full charge segment, a capacity segment, and a feeding segment, and the battery pack includes these three stages, and combined with Figure 1 , Figure 3 , Figure 4 , Figure 5 The working principle of the control circuit for balanced charging based on multi-winding magnetic coupling in the embodiment of the present invention is described as follows:

[0123] For the charging status, when it is detected that the battery pack is in the low-power stage, the control chip MCU first controls the direct charging power conversion module (the source of power VIN in the charging state) and the charging state active balancing module and controls the balance charging power conversion module to open through the feedback loop, so that the branches where the three are located are opened, and the discharge state active balancing module is closed. At this time, the charging current of the balance charging power conversion module is set to 5%-10% of the rated charging current, and then the electrical connection between the direct charging switch and the battery pack is closed, and the SOC change of the battery pack is detected in real time, from 1% to 15% to 20%, and the charging current is gradually increased to the rated current according to this SOC change. During the process of active balanced charging at rated current, if it is detected that the voltage rise rate of one or more batteries is too fast, such as greater than 2%, or its voltage is 10mV higher than the average value of all other batteries in the battery pack at the current moment, the duty cycle of the secondary side of the rectifier control switch module corresponding to the battery is quickly reduced through the feedback loop or the corresponding rectifier control switch module is turned off, thereby reducing the charging current of the battery, making the voltage rise rate of the battery tend to be smooth and consistent with other batteries. When the voltage of the battery is reduced to the same average voltage as other batteries, the battery is charged again. The corresponding rectifier control switch module of the battery pack is turned on or the duty cycle of the secondary side of the corresponding rectifier control switch module is increased to prevent the charging current from being too large and the voltage from rising more slowly, thereby dynamically adjusting the voltage and charging current of each battery to ensure that the voltage and charge of each battery are consistent. When it is detected that the voltage rise rate of all batteries in the battery pack is too fast, such as being greater than 2%, the duty cycle of the primary side of the balanced charging power conversion circuit is reduced through the feedback loop to reduce the average charging current of all batteries and to make the voltage rise rate more gentle, thereby preventing the battery voltage from being too high. The battery pack is continuously monitored. There are battery power changes. When the SOC of the battery pack reaches 18%-23% or the voltage of each battery reaches the same voltage value corresponding to the SOC, first reduce the balancing charge current to 5%-10% of the rated charge current, then turn on the direct charge switch, and then turn off the balancing charge power conversion circuit to directly charge the battery pack. At this time, the voltages of each cell of the battery pack are basically the same, and the voltage difference does not exceed 5mV; when charged to the starting position of the full charge section, such as 85%-90% SOC, the battery voltages are 3.36V, 3.4V, 3.41V, and 3.42V respectively, and the balancing charge is started. Balance the charging power conversion circuit, set the charging current to 5%-10% of the rated charging current, then turn off the direct charging switch, and then adjust the balanced charging current to 30% of the rated charging current. According to the voltage change and the rising slope, the balanced charging current is gradually reduced by 5mV to ensure that the charged amount will not cause a sharp rise in voltage, but to maintain a stable and consistent slow rise in the voltage of each cell, and dynamically maintain the voltage of each battery cell consistent until the voltage of each cell is the same when it is fully charged. This can ensure that the voltage / capacity of each cell is basically the same, and it will not be overcharged, and will not trigger the first and second level overvoltage / overcharge protection.Among them, for the switch switching between the direct charging power conversion module and the balanced charging power conversion circuit, during the charging process, no matter in the power-deficient stage, the capacity stage, the full-charge stage or the junction between two stages, if it is detected that the voltage of a certain section is higher (for example, greater than the current arithmetic mean of 10mV) and / or the voltage rise rate is higher, exceeding the limit, the battery pack is first charged with a small current balanced charge (5%-10%) through the balanced charging power conversion circuit, and then the direct charging switch is turned off, leaving only the balanced charging power conversion circuit to charge each battery section.

[0124] For the discharge state, during the discharge process, due to the large internal resistance of the battery, the external voltage drop rate is large. When it is detected that the voltage of a certain battery is low (such as less than 20mV) or the drop slope is large, the discharge state active balancing module is turned on, and it is connected to the balanced charging power conversion module, and the direct charging switch, the charging state active balancing module (which is also the switch module of the balanced charging power conversion circuit), and the direct charging power conversion module are turned off. At this time, the total battery voltage of the battery pack is passed through the discharge state active balancing module, the balanced charging power conversion circuit and the rectifier control switch module corresponding to the section to charge the battery, and the rectifier control switch modules corresponding to other batteries are turned off. When the battery is charged to the same voltage as the average voltage of other battery sections, the balanced charging is turned off, and the charging current and voltage are adjusted and controlled in real time. This cycle is repeated, and the voltage of each section is dynamically maintained consistent during the entire discharge process.

[0125] It should be noted that for the description of the balancing circuit, the balanced charging power conversion circuit and the balanced charging control circuit, please refer to the description of the relevant content in the first embodiment, which will not be repeated here. It should be noted that it can be expanded to any number of batteries, such as 5 batteries connected in series, 6 batteries connected in series, and 24 batteries connected in series, which is not limited in the embodiment of the present invention.

[0126] It can be seen that implementation Figure 5 The described control circuit for balanced charging based on multi-winding magnetic coupling sets a balanced charging control circuit, a balanced charging power conversion circuit and a balancing circuit, and based on the balanced charging control circuit, actively performs active balancing control on the balancing circuit and the balanced charging power conversion circuit by combining the detected power changes of the battery pack, so that the balancing circuit and the balanced charging power conversion circuit perform balanced charging on the battery pack, so that each battery cell maintains a relatively consistent dynamic voltage and dynamic SOC during use, thereby improving the available capacity of the battery and extending the battery life, and reducing the occurrence of the barrel effect caused by battery series mismatch, or reducing the occurrence of circulating current causing thermal runaway caused by battery parallel charging mismatch, further improving the overall available capacity and extending the service life, and improving the safety and reliability of the battery.

[0127] Embodiment 3

[0128] See also Figure 6 As shown, Figure 6 The structure diagram of a balanced charging control device disclosed in an embodiment of the present invention is a balanced charging control device capable of performing balanced charging on a battery pack when it is in a charging state or performing balanced charging on a battery pack when it is in a discharging state. The balanced charging control device includes a device body and a control circuit, wherein the control circuit is as follows: Figure 1 , Figure 3 , Figure 4 , Figure 5 The described circuit is used to execute the control method for balanced charging based on multi-winding magnetic coupling as described in the first embodiment.

[0129] It should be noted that for a detailed description of the control circuit for balanced charging based on multi-winding magnetic coupling, and a detailed description of the control method for balanced charging based on multi-winding magnetic coupling, please refer to the specific description of the relevant contents in Examples 1 and 2, which will not be repeated in this embodiment.

[0130] It can be seen that the implementation Figure 6 The described balancing charge control device can actively balance the balancing circuit and the balancing charge power conversion circuit through the balancing charge control circuit, the balancing charge power conversion circuit and the balancing circuit, and based on the balancing charge control circuit, by combining the detected power changes of the battery pack, so that the balancing circuit and the balancing charge power conversion circuit perform balanced charging on the battery pack, so that each battery cell maintains a relatively consistent dynamic voltage and dynamic SOC during use, thereby improving the available capacity of the battery and extending the battery life, and reducing the occurrence of the barrel effect caused by battery series mismatch, or reducing the occurrence of circulating current causing thermal runaway caused by battery parallel charging mismatch, further improving the overall available capacity and extending the service life, and improving the safety and reliability of battery use.

[0131] The above is a detailed introduction to a control method, circuit and device for balanced charging based on multi-winding magnetic coupling disclosed in an embodiment of the present invention. Specific embodiments are used in this article to illustrate the principles and implementation methods of the present invention, but the above preferred embodiments are not used to limit the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for a person skilled in the art, based on the idea of ​​the present invention, there will be changes in the specific implementation method and application scope without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A control method for balanced charging based on multi-winding magnetic coupling, characterized in that: The method is applied to a control circuit, which includes a balanced charging power conversion circuit, a balancing circuit and a balanced charging control circuit, wherein: The balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through a multi-winding magnetic coupling method, and the number of all the batteries is greater than or equal to 2; the controlled end of the balanced circuit is electrically connected to the second control end of the balanced charging control circuit, the direct charging end of the balanced circuit is used to electrically connect the battery pack, and the detection end of the balanced charging control circuit is used to electrically connect the battery pack, wherein: The method comprises: The balance charge control circuit detects the charge change of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the charge change of the battery pack, and performs a balance charge control operation on the battery pack.

2. The control method for balanced charging based on multi-winding magnetic coupling according to claim 1, characterized in that: The equalization circuit includes a charging state active equalization module and a direct charging module, wherein: The switch end of the charging state active balancing module is electrically connected to the power supply end of the direct charging module, the controlled end of the direct charging module is electrically connected to the first sub-control end of the balance charging control circuit, and the direct charging end of the direct charging module is used to electrically connect to the battery pack; The balancing end of the charging state active balancing module is electrically connected to the balancing end of the balanced charging power conversion circuit, and the controlled end of the charging state active balancing module is electrically connected to the second sub-control end of the balanced charging control circuit; Among them, the first sub-control end of the balanced charging control circuit and the second sub-control end of the balanced charging control circuit constitute the second control end of the balanced charging control circuit, the balancing end of the charging state active balancing module is the balancing end of the balancing circuit, and the direct charging end of the direct charging module is the direct charging end of the balancing circuit.

3. The control method for balanced charging based on multi-winding magnetic coupling according to claim 2 is characterized in that: The balance charge control circuit detects the change of the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, including: When the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets the predetermined first power condition, the balance charge control circuit generates a connection signal corresponding to the balance charge power conversion circuit, and performs a connection operation on the branch where the balance charge power conversion circuit is located according to the connection signal corresponding to the balance charge power conversion circuit, so that the balance charge power conversion circuit performs a balance charge operation on the battery pack with a preset current; The balance charge control circuit generates a direct charge shutoff signal of the direct charge module, and stops the direct charge operation on the battery pack according to the direct charge shutoff signal of the direct charge module, and after detecting that the direct charge operation on the battery pack is stopped, generates a current increase signal of the balance charge power conversion circuit, and performs an increase operation on the charging current of the balance charge power conversion circuit according to the current increase signal of the balance charge power conversion circuit; During the process of performing a balancing charging operation on the battery pack with the increased charging current of the balancing charging power conversion circuit, the balancing charging control circuit monitors the charge change of the battery pack to obtain a first charge change of the battery pack, and generates a first current reduction signal matching the first charge change of the battery pack based on the first charge change of the battery pack, and performs a reduction operation on the charging current of the balancing charging power conversion circuit based on the first current reduction signal until the voltage of each battery in the battery pack is greater than or equal to a preset voltage.

4. The control method for balanced charging based on multi-winding magnetic coupling according to claim 3 is characterized in that: The balance charge control circuit detects the change of the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, and also includes: When the current state of the battery pack is used to indicate that the power of the battery in the battery pack satisfies a predetermined second power condition, the balancing charge control circuit monitors the second power change of the battery pack, and determines whether the current condition of the battery pack satisfies the determined charging current reduction condition according to the second power change of the battery pack, wherein the charge stored in the battery pack corresponding to the second power condition is less than the charge stored in the battery pack corresponding to the first power condition; When it is determined that the charging current reduction condition is met, the balanced charging control circuit generates a second current reduction signal for the balanced charging power conversion circuit, and performs a charging current reduction operation on the balanced charging power conversion circuit according to the second current reduction signal; The balance charge control circuit generates a direct charge connection signal of the direct charge module, and connects the direct charge terminal of the direct charge module to the battery pack according to the direct charge connection signal of the direct charge module, so as to perform a direct charge operation on the battery pack; The balance charging control circuit generates a shutdown signal corresponding to the balance charging power conversion circuit, and shuts down the balance charging operation of the battery pack according to the shutdown signal corresponding to the balance charging power conversion circuit, and triggers the execution of the operation of generating a corresponding turn-on signal of the balance charging power conversion circuit when the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets the predetermined first power condition.

5. The control method for balanced charging based on multi-winding magnetic coupling according to claim 4 is characterized in that: The balance charge control circuit detects the change of the power of the battery in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, and also includes: When the current state of the battery pack is used to indicate that the power of the battery in the battery pack meets a predetermined third power condition, the balance charge control circuit generates a connection signal of the equalization circuit and a first charging signal of the balance charge power conversion circuit, wherein the charge stored in the battery pack corresponding to the third power condition is less than the charge stored in the battery pack corresponding to the second power condition; The balance charge control circuit controls the balance circuit to turn on the balance charge power conversion circuit according to the turn-on signal of the balance circuit, and controls the balance charge power conversion circuit to perform a charging operation on the battery pack with a first charging current matching the first charging signal according to the first charging signal of the balance charge power conversion circuit; The balancing charge control circuit detects a third charge change of the battery pack, and generates a second charging signal for the balancing charge power conversion circuit according to the third charge change of the battery pack, and increases the charging current of the balancing charge power conversion circuit according to the second charging signal, and triggers the execution of the operation of monitoring the second charge change of the battery pack when the current state of the battery pack is used to indicate that the charge of the battery in the battery pack meets the predetermined second charge condition.

6. The control method for balanced charging based on multi-winding magnetic coupling according to claim 5, characterized in that: The method further comprises: The balance charge control circuit determines whether the direct charge terminal of the direct charge module is disconnected from the battery pack, and when the determination result is yes, triggers the execution of the operation of detecting the third power change of the battery pack; When the result is judged to be negative, the balance charging control circuit generates a first shutdown signal, and according to the first shutdown signal, disconnects the connection between the direct charging end of the direct charging module and the battery pack, and triggers the operation of detecting the third charge change of the battery pack.

7. The control method for balanced charging based on multi-winding magnetic coupling according to any one of claims 3 to 5, characterized in that: The method further comprises: In the process of charging the battery pack based on the balanced charging power conversion circuit, the balanced charging control circuit detects the first voltage change of each battery in the battery pack, and determines the voltage change type corresponding to the battery pack according to the first voltage change of each battery; When the voltage change type corresponding to the battery pack is used to indicate that there is a first target battery in the battery pack whose voltage change meets a predetermined first current regulation condition, the balancing charge control circuit generates a first current control signal matching the voltage change of the first target battery, and performs a reduction operation on the current charging current of the battery pack according to the first current control signal corresponding to the first target battery; after charging the first target battery with the reduced current charging current of the first target battery, when it is determined that the current voltage change of the first target battery meets a predetermined second current regulation condition, generates a second current control signal matching the voltage change of the first target battery, and performs an increase operation on the current charging current of the battery pack according to the second current control signal corresponding to the first target battery; When the voltage change type corresponding to the battery pack is used to indicate that the voltage change conditions of all batteries in the battery pack meet a predetermined second current regulation condition, the balancing charge control circuit generates a duty cycle control signal that matches the voltage change conditions corresponding to the battery pack, and according to the duty cycle control signal, performs a pulse width duty cycle reduction operation on the primary side corresponding to the balancing charge power conversion circuit to reduce the current charging current of the battery pack.

8. The control method for balanced charging based on multi-winding magnetic coupling according to claim 1, characterized in that: The balancing circuit includes a discharge state active balancing module, wherein the balancing end of the discharge state active balancing module is electrically connected to the balancing end of the balanced charging power conversion circuit, and the charging end of the discharge state active balancing module is used to electrically connect the battery pack; wherein the balancing end of the discharge state active balancing module is the balancing end of the balancing circuit, and the charging end of the discharge state active balancing module is the direct charging end of the balancing circuit; The balance charge control circuit detects the change of the battery power in the battery pack, and controls the equalization circuit and the balance charge power conversion circuit according to the change of the battery power corresponding to the battery pack, and performs a balance charge control operation on the battery pack, including: When it is determined that there is a second target battery whose current voltage is less than or equal to a predetermined voltage threshold or whose current voltage change rate is greater than or equal to a predetermined voltage change threshold during the discharge process of the battery pack, the balance charge control circuit generates a discharge equalization signal corresponding to the second target battery and a shutdown signal corresponding to each remaining battery in the battery pack except the second target battery, and performs an opening operation on the discharge state active equalization module according to the discharge equalization signal, so that the discharge state active equalization module is connected to the balance charge power conversion circuit, and at the same time, according to the shutdown signal corresponding to each remaining battery, disconnects the charging branch of the remaining battery; During the process of performing balance charging on the second target battery, when it is monitored that the difference between the voltage of the second target battery and the average voltage of all the remaining batteries is less than or equal to a preset voltage difference, the balance charging control circuit generates a shutdown signal corresponding to the second target battery, and according to the shutdown signal corresponding to the second target battery, disconnects the charging branch of the second target battery, and re-determines whether there is a second target battery in the battery pack during the discharge process whose current voltage is less than or equal to a predetermined voltage threshold or whose current voltage change rate is greater than or equal to a predetermined voltage change threshold.

9. A control circuit for balanced charging based on multi-winding magnetic coupling, characterized in that: The control circuit includes a balanced charging power conversion circuit, a balancing circuit and a balanced charging control circuit, wherein: The balancing end of the balanced charging power conversion circuit is electrically connected to the balancing end of the balancing circuit, the controlled end of the balanced charging power conversion circuit is electrically connected to the first control end of the balanced charging control circuit, and the charging end of the balanced charging power conversion circuit is used to connect each battery in the battery pack through multi-winding magnetic coupling, and the number of all the batteries is greater than or equal to 2; The controlled end of the balancing circuit is electrically connected to the second control end of the balancing charge control circuit, the direct charging end of the balancing circuit is used to electrically connect to the battery pack, and the detection end of the balancing charge control circuit is used to electrically connect to the battery pack; The balance charge control circuit is used to detect the charge change of the battery in the battery pack, and control the equalization circuit and the balance charge power conversion circuit according to the charge change of the battery pack, so as to perform balance charge control operation on the battery pack.

10. A balanced charging control device, comprising a device body and a control circuit in a balanced charging control method based on multi-winding magnetic coupling as described in any one of claims 1-8, and the device body is used to place the control circuit, and the balanced charging control device is used to execute the balanced charging control method based on multi-winding magnetic coupling as described in any one of claims 1-8.

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