A control device, method and vehicle for a battery equalization system

Abstract

The present invention discloses a control device, a method and an automobile for a battery equalization system. The battery equalization system includes: a storage battery, a switching unit, a transformer, a selection unit and a battery pack; the switching unit is arranged between the storage battery and the primary winding of the transformer; the selection unit is arranged between the secondary winding of the transformer and the battery pack; the control device of the battery equalization system includes: a detection unit and a control unit; wherein, the detection unit is configured to detect whether the energy of any single battery in the battery pack exceeds a set energy range; the control unit is configured to, when the energy of any single battery in the battery pack exceeds the set energy range, control the switch of the switching unit and control the selection unit to select the single battery in the battery pack so as to achieve energy equalization between the single battery and the storage battery. By reducing the number of transformers, the cost can be reduced with this solution.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supplies, and particularly relates to a control device, a method and an automobile for a battery equalization system, and more particularly to a battery non-dissipative equalization system, an automobile having the battery non-dissipative equalization system, and a battery non-dissipative energy transfer method for the automobile. Background Art

[0002] The battery equalization topology is to transfer energy using the battery equalization topology when the voltages of individual cells in a battery pack are inconsistent, so as to alleviate the problem of voltage inconsistency among individual cells in the battery pack.

[0003] In the battery equalization topologies of related solutions, most of them are that one individual cell is connected to one transformer, and each battery pack contains multiple transformers. The large number of transformers results in a high cost.

[0004] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a control device, a method and an automobile for a battery equalization system, so as to solve the problem that in the battery equalization topology, one individual cell is connected to one transformer, resulting in a large number of transformers in the battery pack and a high cost, and achieve the effect of reducing the cost by reducing the number of transformers.

[0006] In a control device for a battery equalization system provided by the present invention, the battery equalization system includes: a storage battery, a switch unit, a transformer, a selection unit and a battery pack; the switch unit is arranged between the storage battery and the primary winding of the transformer; the selection unit is arranged between the secondary winding of the transformer and the battery pack; the control device for the battery equalization system includes: a detection unit and a control unit; wherein, the detection unit is configured to detect whether the energy of any individual cell in the battery pack exceeds a set energy range; the control unit is configured to, when the energy of any individual cell in the battery pack exceeds the set energy range, control the switch of the switch unit and control the selection unit to select the individual cell in the battery pack, so as to achieve energy equalization between the individual cell and the storage battery.

[0007] In some embodiments, the switching unit includes: a first switching module; the selection unit includes: a second switching module to a (2n + 1)-th switching module; the battery pack includes: a first single cell and an n-th single cell, where n is a positive integer; wherein, the first switching module is disposed between the positive electrode of the storage battery and one end of the primary winding of the transformer; the first single cell to the n-th single cell are connected in series; among the first single cell to the n-th single cell, the positive electrode of each single cell is connected to the first end of the secondary winding of the transformer through one of the switching modules from the second switching module to the (2n + 1)-th switching module; the negative electrode of each single cell is connected to the second end of the secondary winding of the transformer through another one of the switching modules from the second switching module to the (2n + 1)-th switching module.

[0008] In some embodiments, any one of the first switching module, the second switching module to the (2n + 1)-th switching module includes: a switching tube.

[0009] In some embodiments, when the energy of any single cell in the battery pack exceeds the set energy range, it includes: the case where the energy of any single cell in the battery pack is higher than the upper limit of the set energy range; the control unit, when the energy of any single cell in the battery pack exceeds the set energy range, controls the switches of the switching unit and controls the selection unit to select the single cell in the battery pack, including: when the energy of any single cell in the battery pack is higher than the upper limit of the set energy range, controlling the selection unit to select the single cell in the battery pack so as to form a closed loop between the single cell in the battery pack and the secondary winding of the transformer, and partially transmitting and storing the energy of the single cell in the battery pack to the secondary winding of the transformer; controlling the switching unit to be turned on so that the primary coil of the transformer forms a closed loop with the storage battery, transferring the energy stored in the secondary winding of the transformer to the primary coil of the transformer, and reversely supplying power to the storage battery through the energy obtained in the primary coil of the transformer; when the energy of the single cell in the battery pack is released to a first set energy, controlling the switching unit to be turned off so that the closed loop formed between the storage battery and the primary coil of the transformer is disconnected; and controlling the selection unit to cancel the selection of the single cell in the battery pack so that the closed loop formed between the single cell in the battery pack and the secondary winding of the transformer is disconnected.

[0010] In some embodiments, when the energy of any single battery cell in the battery pack exceeds the set energy range, it further includes: when the energy of any single battery cell in the battery pack is lower than the lower limit of the set energy range; the control unit, when the energy of any single battery cell in the battery pack exceeds the set energy range, controls the switch of the switch unit and controls the selection unit to select this single battery cell in the battery pack, and further includes: when the energy of any single battery cell in the battery pack is lower than the lower limit of the set energy range, controls the switch unit to be turned on so that the primary coil of the transformer forms a closed loop with the storage battery, transfers part of the energy of the storage battery to the primary coil of the transformer and stores it; controls the selection unit to select this single battery cell in the battery pack so that a closed loop is formed between this single battery cell in the battery pack and the secondary winding of the transformer, transfers the energy stored in the primary winding of the transformer to the secondary coil of the transformer, and transfers the energy obtained in the secondary coil of the transformer to this single battery cell in the battery pack; when the energy of this single battery cell in the battery pack is released to the second set energy, controls the switch unit to be turned off so that the closed loop formed between the storage battery and the primary coil of the transformer is disconnected; and controls the selection unit to cancel the selection of this single battery cell in the battery pack so that the closed loop formed between this single battery cell in the battery pack and the secondary winding of the transformer is disconnected.

[0011] Matched with the above device, on the other hand, the present invention provides an automobile, including: the control device of the above battery equalization system.

[0012] Matched with the above automobile, on the other hand, in a control method of a battery equalization system provided by the present invention, the battery equalization system includes: a storage battery, a switch unit, a transformer, a selection unit and a battery pack; the switch unit is arranged between the storage battery and the primary winding of the transformer; the selection unit is arranged between the secondary winding of the transformer and the battery pack; the control method of the battery equalization system includes: detecting whether the energy of any single battery cell in the battery pack exceeds the set energy range; when the energy of any single battery cell in the battery pack exceeds the set energy range, controlling the switch of the switch unit and controlling the selection unit to select this single battery cell in the battery pack to achieve energy equalization between this single battery cell and the storage battery.

[0013] In some embodiments, the situation where the energy of any single battery in the battery pack exceeds the set energy range includes: the situation where the energy of any single battery in the battery pack is higher than the upper limit of the set energy range; when the energy of any single battery in the battery pack exceeds the set energy range, controlling the switch of the switch unit and controlling the selection unit to select this single battery in the battery pack, including: when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range, controlling the selection unit to select this single battery in the battery pack so as to form a closed loop between this single battery in the battery pack and the secondary winding of the transformer, and partially transmit and store the energy of this single battery in the battery pack to the secondary winding of the transformer; controlling the switch unit to be turned on so as to form a closed loop between the primary coil of the transformer and the storage battery, transfer the energy stored in the secondary winding of the transformer to the primary coil of the transformer, and supply power to the storage battery in reverse through the energy obtained in the primary coil of the transformer; when the energy of this single battery in the battery pack is released to the first set energy, controlling the switch unit to be turned off so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and controlling the selection unit to cancel the selection of this single battery in the battery pack so as to disconnect the closed loop formed between this single battery in the battery pack and the secondary winding of the transformer.

[0014] In some embodiments, when the energy of any single battery in the battery pack exceeds the set energy range, it further includes: when the energy of any single battery in the battery pack is lower than the lower limit of the set energy range; when the energy of any single battery in the battery pack exceeds the set energy range, control the switch of the switch unit and control the selection unit to select this single battery in the battery pack, and it further includes: when the energy of any single battery in the battery pack is lower than the lower limit of the set energy range, control the switch unit to turn on, so that the primary coil of the transformer forms a closed loop with the storage battery, transfer part of the energy of the storage battery to the primary coil of the transformer and store it; control the selection unit to select this single battery in the battery pack, so that a closed loop is formed between this single battery in the battery pack and the secondary winding of the transformer, transfer the energy stored in the primary winding of the transformer to the secondary coil of the transformer, and transfer the energy obtained in the secondary coil of the transformer to this single battery in the battery pack; when the energy of this single battery in the battery pack is released to the second set energy, control the switch unit to turn off, so that the closed loop formed between the storage battery and the primary coil of the transformer is disconnected; and control the selection unit to cancel the selection of this single battery in the battery pack, so that the closed loop formed between this single battery in the battery pack and the secondary winding of the transformer is disconnected.

[0015] Thus, in the solution of the present invention, by setting a transformer between the vehicle-mounted power supply and the battery pack, and arranging switching tubes between the secondary coil of the transformer and the positive and negative electrodes of each single battery in the battery pack, the conduction of the switching tubes is used to select the target single battery to be connected to the transformer, realizing two-way energy transfer, so that any battery in the battery pack reaches an equilibrium state, and by reducing the number of transformers, the cost is reduced.

[0016] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention.

[0017] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of an embodiment of the control device of the battery equalization system of the present invention;

[0019] Figure 2 It is a schematic structural diagram of an embodiment of the battery equalization system;

[0020] Figure 3 It is a schematic flowchart of an embodiment of the control method of the battery equalization system of the present invention;

[0021] Figure 4 A schematic flowchart of an embodiment for controlling the switching unit and the selection unit when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range in the method of the present invention;

[0022] Figure 5 A schematic flowchart of an embodiment for controlling the switching unit and the selection unit when the energy of any single battery in the battery pack is lower than the lower limit of the set energy range in the method of the present invention. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] According to an embodiment of the present invention, a control device for a battery equalization system is provided. Refer to Figure 1 A schematic structural diagram of an embodiment of the device of the present invention shown. The battery equalization system includes: a storage battery, a switching unit, a transformer, a selection unit, and a battery pack. The switching unit is disposed between the storage battery and the primary winding of the transformer and is configured to control the connection or disconnection between the storage battery and the primary winding of the transformer. The selection unit is disposed between the secondary winding of the transformer and the battery pack and is configured to select any single battery in the battery pack to be connected to the secondary winding of the transformer. The storage battery may be a vehicle-mounted power supply E, such as a low-voltage vehicle-mounted storage battery. The switching unit may be a switching tube, such as MOS tube S 1 The selection unit may be a switching tube, such as MOS tube S 2 to MOS tube S 2n+1 , where n is a positive integer.

[0025] The control device for the battery equalization system includes: a detection unit and a control unit. The detection unit is, for example, a battery energy detection device. The control unit is, for example, an MCU, a DSP, etc.

[0026] Wherein, the detection unit is configured to detect whether the energy of any single battery in the battery pack exceeds a set energy range.

[0027] The control unit is configured to control the switch of the switch unit and control the selection unit to select the single cell in the battery pack when the energy of any single cell in the battery pack exceeds the set energy range, so as to achieve the energy balance between the single cell and the storage battery, that is, to achieve the bidirectional energy transfer between the low-voltage storage battery and the power battery pack.

[0028] Specifically, by controlling the switch of the switch unit and using the selection unit, such as the conduction of a switching tube, to select the target single cell and connect it to the transformer, bidirectional energy transfer is achieved, so that any cell in the battery pack reaches an equilibrium state; the entire battery balancing system can use a single transformer to charge and discharge all target cells, achieving the energy balance of the battery system. Compared with other solutions, the number of transformers is reduced, and the cost is greatly reduced.

[0029] In some embodiments, the switch unit includes: a first switch module (such as MOS transistor S 1 ). The selection unit includes: a second switch module to a (2n + 1)-th switch module (such as MOS transistors S 2 to MOS transistor S 2n+1 ). The battery pack includes: a first single cell and an n-th single cell, where n is a positive integer.

[0030] Wherein, the first switch module is disposed between the positive electrode of the storage battery and one end of the primary winding of the transformer. For example, the first end of the primary winding of the transformer is connected to the positive electrode of the storage battery through the first switch module, and the second end of the primary winding of the transformer is connected to the negative electrode of the storage battery.

[0031] The first single cell to the n-th single cell are connected in series. Among the first single cell to the n-th single cell, the positive electrode of each single cell is connected to the first end of the secondary winding of the transformer through one of the switch modules from the second switch module to the (2n + 1)-th switch module. The negative electrode of each single cell is connected to the second end of the secondary winding of the transformer through another one of the switch modules from the second switch module to the (2n + 1)-th switch module.

[0032] Specifically, the battery non-dissipative balancing system mainly consists of an on-vehicle power supply E (such as a 24V low-voltage on-vehicle storage battery), a transformer T 1 , n single cells, and 2n + 1 switching tubes (such as MOS transistors), etc. The 24V low-voltage on-vehicle storage battery is connected to the primary coil of the transformer T 1 through a MOS transistor (such as MOS transistor S 1 . The primary coil of the transformer T is connected to the positive electrode of the storage battery through a MOS transistor (such as MOS transistor S 1 to B nEach single battery in the power battery pack composed in series is connected to the secondary coil of the transformer T through a corresponding switching tube such as MOS tube S 2 to MOS tube S 2n+1 connected to the secondary coil of the transformer T 1 . Here, n is a positive integer.

[0033] In some embodiments, any one of the first switching module, the second switching module to the (2n + 1)-th switching module includes: a switching tube. The switching tube can be a metal oxide semiconductor field effect transistor (MOSFET), or an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), etc.

[0034] In some embodiments, the situation that the energy of any single battery in the battery pack exceeds the set energy range includes: the situation that the energy of any single battery in the battery pack is higher than the upper limit of the set energy range.

[0035] The control unit, when the energy of any single battery in the battery pack exceeds the set energy range, controls the switch of the switching unit and controls the selection unit to select this single battery in the battery pack, including:

[0036] Specifically, the control unit is further configured to, when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range, control the selection unit to select this single battery in the battery pack, so as to form a closed loop between this single battery in the battery pack and the secondary winding of the transformer, and partially transfer and store the energy of this single battery in the battery pack to the secondary winding of the transformer.

[0037] Specifically, the control unit is further configured to control the switching unit to be turned on, so as to form a closed loop between the primary coil of the transformer and the storage battery, transfer the energy stored in the secondary winding of the transformer to the primary coil of the transformer, and supply power to the storage battery in reverse through the energy obtained in the primary coil of the transformer.

[0038] Specifically, the control unit is further configured to, when the energy of this single battery in the battery pack is released to the first set energy, that is, when the energy of this single battery in the battery pack is released to the set balanced state, control the switching unit to be turned off, so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and control the selection unit to cancel the selection of this single battery in the battery pack, so as to disconnect the closed loop formed between this single battery in the battery pack and the secondary winding of the transformer.

[0039] Specifically, when the battery non-dissipative equalization system detects that the energy of the target single cell is too high, the corresponding switch tube such as the MOS tube is closed, and a part of the energy of the target single cell is transferred to the secondary coil of the transformer T. 1 The energy transferred out of the target single cell is stored in the form of a magnetic field. Taking the case where the battery non-dissipative equalization system detects that the energy of the single cell B 1 is relatively high as an example, the single cell B 1 is the target single cell, and the switch tubes S 2 and S 3 are closed, so that the target single cell, that is, the single cell B 1 forms a closed loop with the secondary coil of the transformer T 1 , and the energy of the target single cell such as the single cell B1 is transferred to the secondary coil of the transformer T 1 for storage. Subsequently, the switch tube S 1 is closed, and the energy stored in the secondary coil of the transformer T 1 is transferred to the primary coil of the transformer T 1 . The primary coil of the transformer T 1 forms a closed loop with the low-voltage vehicle-mounted power supply (i.e., the vehicle-mounted power supply E) to supply power to the low-voltage vehicle-mounted battery (i.e., the vehicle-mounted power supply E) in reverse. When the target single cell such as the single cell B 1 releases energy to reach the set equalization state, the switch tubes S 1 , S 2 , and S 3 are disconnected, and the target single cell such as the single cell B 1 is equalized.

[0040] In some embodiments, when any single cell in the battery pack has an energy exceeding the set energy range, it further includes: when any single cell in the battery pack has an energy lower than the lower limit of the set energy range.

[0041] The control unit, when any single cell in the battery pack has an energy exceeding the set energy range, controls the switches of the switch unit and controls the selection unit to select this single cell in the battery pack. It further includes:

[0042] The control unit is specifically further configured to, when any single cell in the battery pack has an energy lower than the lower limit of the set energy range, control the switch unit to be turned on, so that the primary coil of the transformer forms a closed loop with the storage battery, and partially transfer the energy of the storage battery to the primary coil of the transformer and store it.

[0043] The control unit is specifically further configured to control the selection unit to select the single battery in the battery pack, so as to form a closed loop between the single battery in the battery pack and the secondary winding of the transformer, transfer the energy stored in the primary winding of the transformer to the secondary coil of the transformer, and transfer the energy obtained in the secondary coil of the transformer to the single battery in the battery pack.

[0044] The control unit is specifically further configured to, when the energy of the single battery in the battery pack is released to a second set energy, that is, when the energy of the single battery in the battery pack is replenished to a set balanced state, control the switch unit to disconnect, so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and control the selection unit to cancel the selection of the single battery in the battery pack, so as to disconnect the closed loop formed between the single battery in the battery pack and the secondary winding of the transformer.

[0045] Specifically, when the battery non-dissipative equalization system detects that the energy of the target single battery is too low, taking single battery B 2 as an example, first close the switch tube S 1 , the low-voltage storage battery (i.e., vehicle-mounted power supply E) discharges, and transfers a part of the energy of the low-voltage storage battery (i.e., vehicle-mounted power supply E) to the primary coil of the transformer T 1 , then close the switch tube S 4 and the switch tube S 5 , the energy of the primary coil of the transformer T 1 is transferred to the secondary coil of the transformer T 1 , and at the same time, the target single battery such as single battery B 2 forms a closed loop with the secondary coil of the transformer T 1 , and the energy in the secondary coil of the transformer T 1 is transferred to the target single battery such as single battery B 2 , to charge the lower target single battery such as single battery B 2 . When the equalization operation is completed, then disconnect the switch tube S 1 , the switch tube S 4 , the switch tube S 5 .

[0046] Thus, by using a switch tube such as a MOS tube to select the target single battery to be connected to the transformer, through the charge and discharge function of the battery pack, the bidirectional energy transfer between the low-voltage storage battery and the power battery pack is realized, so that any battery in the power battery pack reaches a balanced state; the whole system only needs to use one transformer to perform charge and discharge operations on all target batteries, realizing the equalization of the battery system, reducing the number of transformers, and greatly reducing the cost.

[0047] After a large number of experimental verifications, by adopting the technical solution of the present invention, a transformer is provided between the vehicle-mounted power supply and the battery pack, and switching tubes are provided between the secondary coil of the transformer and the positive and negative electrodes of each single battery in the battery pack. The conduction of the switching tubes is used to select the target single battery to be connected to the transformer, so as to realize bidirectional energy transfer, make any battery in the battery pack reach an equilibrium state, and reduce the cost by reducing the number of transformers.

[0048] According to an embodiment of the present invention, a vehicle corresponding to the control device of the battery equalization system is also provided. The vehicle may include: the control device of the battery equalization system described above.

[0049] Battery equalization topologies can generally be divided into two types, namely dissipative equalization strategies and non-dissipative equalization strategies.

[0050] Among them, in the dissipative equalization method, it is consumed in the form of heat through an equalization resistor, and there will be relatively large energy losses.

[0051] There are relatively more non-dissipative equalization methods. For example, the switching tube capacitor scheme, the switching tube inductor scheme, the flyback transformer scheme, and the integrated DC-DC converter scheme, etc. The non-dissipative scheme is to use a transformer to realize the bidirectional energy transmission between the single battery and the whole battery pack (i.e., the battery pack), so that the energy of the cell with a higher average value is transferred to the battery pack to reduce the voltage of the target single battery, or charge the cell with a lower voltage from the battery pack to achieve the balance between battery cells.

[0052] In related solutions, the low-voltage sides of all bidirectional DC / DC converters (i.e., DC / DC converters) used in the entire power battery pack share a low-voltage bus; a passive equalization circuit and an active equalizer are combined to realize the equalization management of all power battery packs. In this solution, an active equalization scheme is adopted for each battery pack, but a passive equalization strategy is adopted for the equalization of battery cells, which is easy to consume energy, and multiple DC / DC converters are used, and the cost of the scheme is relatively high.

[0053] In some embodiments, in view of the problems such as small equalization current and complex equalization process existing in the battery management system in related solutions, the solution of the present invention proposes a new equalization topology and equalization strategy for the battery management system.

[0054] In related solutions, the equalization scheme is passive equalization, which is realized by connecting a resistor in parallel at both ends of the single cell, and the equalization current is generally below 0.5A. In the solution of the present invention, the circuit topology can achieve an equalization of more than 2A.

[0055] In some embodiments, the solution of the present invention proposes a novel battery management system balancing topology and a corresponding balancing strategy. The implementation of the balancing strategy is relatively simple. By using the conduction of the switching tube to select the target single cell to be connected to the transformer, bidirectional energy transfer is achieved, enabling any cell in the battery pack to reach an equilibrium state. The entire battery balancing system can perform charge and discharge operations on all target batteries with just one transformer, achieving energy balance in the battery system. Compared with other solutions, the number of transformers is reduced, significantly lowering the cost.

[0056] The balancing solution proposed by the solution of the present invention has a relatively simple topology, can perform high-current balancing, and the magnitude of the balancing current is restricted by the transformer and can vary according to the change of the transformer. By controlling the switching tube, the transformer is connected to the target single cell to achieve bidirectional energy transfer. One transformer can cover the charge and discharge control of multiple single cells, reducing the number of transformers and effectively lowering the cost. When the transformer reaches the rated current, it will exhibit a saturation characteristic. Therefore, the magnitude of the balancing current is the same as the rated current of the transformer itself.

[0057] Figure 2 It is a schematic structural diagram of an embodiment of the battery balancing system. Figure 2 In the lower left box in, it indicates that the simplified switching tube is equivalent to the MOS tube (i.e., MOSFET) M 1 and diode D 1 combination. In the combination of MOS tube M 1 and diode D 1 combination, the S pole (i.e., source) of the N-channel or P-channel MOS tube M 1 and the D pole (i.e., drain) of the N-channel or P-channel MOS tube M 1 are connected to a parasitic diode D 1 connection. The G (i.e., gate) of the N-channel or P-channel MOS tube M 1 is the control signal terminal connected to the outside. The S pole (i.e., source) of the N-channel or P-channel MOS tube M 1 is connected to the cathode of the parasitic diode D 1 , and the D pole (i.e., drain) of the N-channel or P-channel MOS tube M 1 is connected to the anode of the parasitic diode D 1 .

[0058] As Figure 2 shown, the non-dissipative battery balancing system provided by the solution of the present invention mainly consists of a vehicle-mounted power supply E (such as a 24V low-voltage vehicle-mounted battery), a transformer T 1 , n single cells, and 2n + 1 switching tubes (such as MOS tubes), etc. The 24V low-voltage vehicle-mounted battery is connected to the transformer T through a MOS tube (such as MOS tube S 1 )1 is connected to the primary coil of 1 , and each single battery in the power battery pack composed of n single batteries B 1 to B n connected in series is connected to the secondary coil of the transformer T through a corresponding switching tube such as MOS tube S 2 to MOS tube S 2n+1 . Among them, n is a positive integer. 1 is connected to the secondary coil of the transformer T. Among them, n is a positive integer.

[0059] In Figure 2 the example shown, the entire battery equalization system only uses one transformer T 1 to achieve the equalization operation, reducing the number of transformers; the vehicle-mounted power supply E and the transformer T 1 are connected to the primary coil by controlling a switching tube (such as MOS tube S 1 ) to achieve the mutual transfer of energy. Compared with the related solution where one single battery is connected to one transformer. In the solution of the present invention, by turning on the switching tube (such as MOS tube S 1 ), each time a single battery is selected to be connected to the transformer T 1 , there is no need to connect one transformer to each battery, effectively reducing the number of transformers and lowering the cost.

[0060] In Figure 2 the example shown, in the solution of the present invention, the transformer T 1 can limit the current output by the battery pack, that is, a suitable type of transformer T 1 can be selected according to the magnitude of the target equalization current.

[0061] In some embodiments, in the solution of the present invention, the equalization strategy of the non-dissipative battery equalization system, that is, the non-dissipative energy transfer method, includes:

[0062] The first step: When the non-dissipative battery equalization system detects that the energy of the target single battery is too high, then close the corresponding switching tube such as the MOS tube, and transfer a part of the energy of the target single battery to the secondary coil of the transformer T 1 . The energy transferred out from the target single battery is stored in the form of a magnetic field. Taking the case where the non-dissipative battery equalization system detects that the energy of the single battery B 1 is relatively high as an example, then the single battery B 1 is the target single battery, close the switching tube S 2 and the switching tube S 3 , so that the target single battery, that is, the single battery B 1 forms a closed loop with the secondary coil of the transformer T 1 , and transfer the energy of the target single battery such as the single battery B1 to the transformer T 1Stored in the secondary coil. The single-cell battery voltage is detected by the microcontroller. When the voltage is higher, the energy of the single-cell battery is higher; when the voltage is lower, the energy of the single-cell battery is lower.

[0063] Step 2: Then close the switch tube S 1 , and the transformer T 1 The energy stored in the secondary coil is transferred to the primary coil of the transformer T 1 . The primary coil of the transformer T 1 Forms a closed loop with the low-voltage vehicle-mounted power supply (i.e., vehicle-mounted power supply E) to supply power to the low-voltage vehicle-mounted battery (i.e., vehicle-mounted power supply E) in reverse.

[0064] Step 3: When the target single-cell battery, such as single-cell battery B 1 Releases energy to reach the set equalization state (detect whether the voltage of the single-cell battery reaches the threshold), then disconnect the switch tube S 1 , switch tube S 2 , switch tube S 3 . The target single-cell battery, such as single-cell battery B 1 Is equalized.

[0065] Step 4: Similarly, when the battery non-dissipative equalization system detects that the energy of the target single-cell battery is too low, taking single-cell battery B 2 As an example, first close the switch tube S 1 . The low-voltage storage battery (i.e., vehicle-mounted power supply E) discharges, and a part of the energy of the low-voltage storage battery (i.e., vehicle-mounted power supply E) is transferred to the primary coil of the transformer T 1 . Then close the switch tube S 4 And switch tube S 5 . The energy of the primary coil of the transformer T 1 Is transferred to the secondary coil of the transformer T 1 . At the same time, the target single-cell battery, such as single-cell battery B 2 Forms a closed loop with the secondary coil of the transformer T 1 . The energy in the secondary coil of the transformer T 1 Is transferred to the target single-cell battery, such as single-cell battery B 2 To charge the lower target single-cell battery, such as single-cell battery B 2 . When the equalization operation is completed, then disconnect the switch tube S 1 , switch tube S 4 , switch tube S 5 .

[0066] Through the above process, the bidirectional energy transfer between the low-voltage storage battery and the power battery pack can be realized.

[0067] In the solution of the present invention, the above-mentioned switching tube can be a metal-oxide-semiconductor field-effect transistor (MOSFET), or an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), etc. The low-voltage vehicle-mounted battery can be 24V or 12V.

[0068] It can be seen that the solution of the present invention proposes a novel battery management system balancing topology and balancing strategy. By using a switching tube such as an MOS tube to select a target single battery to be connected to the transformer, and through the charge and discharge functions of the battery pack, bidirectional energy transfer between the low-voltage battery and the power battery pack is achieved, enabling any battery in the power battery pack to reach an equilibrium state. The entire system only needs to use one transformer to perform charge and discharge operations on all target batteries, realizing the balance of the battery system, reducing the number of transformers, and significantly reducing costs.

[0069] Since the processing and functions implemented by the vehicle in this embodiment basically correspond to the embodiments, principles, and examples of the device shown above Figure 1 For the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments and will not be elaborated here.

[0070] Verified by a large number of experiments, adopting the technical solution of the present invention, by setting a transformer between the vehicle-mounted power supply and the battery pack, and setting switching tubes between the secondary coil of the transformer and the positive and negative electrodes of each single battery in the battery pack, one transformer can be used to perform charge and discharge operations on all target batteries, realizing the energy balance of the battery system. Compared with other solutions, the number of transformers is reduced, and the cost is significantly reduced.

[0071] According to an embodiment of the present invention, there is also provided a control method for a battery balancing system corresponding to a vehicle, as Figure 3 shown in the schematic flowchart of an embodiment of the method of the present invention. The battery balancing system includes: a storage battery, a switching unit, a transformer, a selection unit, and a battery pack. The switching unit is disposed between the storage battery and the primary winding of the transformer and is configured to control the connection or disconnection between the storage battery and the primary winding of the transformer. The selection unit is disposed between the secondary winding of the transformer and the battery pack and is configured to select any single battery in the battery pack to be connected to the secondary winding of the transformer. The storage battery can be a vehicle-mounted power supply E, such as a low-voltage vehicle-mounted battery. The switching unit can be a switching tube such as an MOS tube S 1 . The selection unit can be a switching tube such as an MOS tube S 2 to MOS tube S 2n+1 , where n is a positive integer.

[0072] The control method of the battery balancing system includes: step S110 and step S120.

[0073] At step S110, it is detected whether the energy of any single battery in the battery pack exceeds a set energy range.

[0074] At step S120, when the energy of any single battery in the battery pack exceeds the set energy range, the switch of the switch unit is controlled, and the selection unit is controlled to select the single battery in the battery pack, so as to achieve energy balance between the single battery and the storage battery, that is, to achieve bidirectional energy transfer between the low-voltage storage battery and the power battery pack.

[0075] Among them, the detection unit is, for example, a battery energy detection device. The control unit is, for example, an MCU, a DSP, etc.

[0076] Specifically, by controlling the switch of the switch unit and using the conduction of the selection unit such as a switching tube to select the target single battery and connect it to the transformer, bidirectional energy transfer is realized, so that any battery in the battery pack reaches an equilibrium state. The entire battery balancing system can use one transformer to charge and discharge all target batteries, realizing energy balance of the battery system. Compared with other solutions, the number of transformers is reduced, and the cost is greatly reduced.

[0077] In some embodiments, the situation that the energy of any single battery in the battery pack exceeds the set energy range includes: the situation that the energy of any single battery in the battery pack is higher than the upper limit of the set energy range.

[0078] In step S120, when the energy of any single battery in the battery pack exceeds the set energy range, the switch of the switch unit is controlled, and the selection unit is controlled to select the single battery in the battery pack, including: the first control process of controlling the switch unit and the selection unit when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range.

[0079] The following combines Figure 4 The schematic flowchart of an embodiment of controlling the switch unit and the selection unit when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range in the method of the present invention shown, and further illustrates the specific process of controlling the switch unit and the selection unit when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range, including: steps S210 to S230.

[0080] Step S210, when the energy of any single battery in the battery pack is higher than the upper limit of the set energy range, control the selection unit to select this single battery in the battery pack, so as to form a closed loop between this single battery in the battery pack and the secondary winding of the transformer, and partially transfer and store the energy of this single battery in the battery pack to the secondary winding of the transformer.

[0081] Step S220, control the switch unit to be turned on, so as to form a closed loop between the primary coil of the transformer and the storage battery, transfer the energy stored in the secondary winding of the transformer to the primary coil of the transformer, and supply power to the storage battery in reverse through the energy obtained in the primary coil of the transformer.

[0082] Step S230, when the energy of this single battery in the battery pack is released to the first set energy, that is, when the energy of this single battery in the battery pack is released to the set balanced state, control the switch unit to be turned off, so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and control the selection unit to cancel the selection of this single battery in the battery pack, so as to disconnect the closed loop formed between this single battery in the battery pack and the secondary winding of the transformer.

[0083] Specifically, when the battery non-dissipative equalization system detects that the energy of the target single battery is too high, then close the corresponding switching tube such as the MOS tube, and transfer a part of the energy of the target single battery to the transformer T 1 in the secondary coil. The energy transferred out of the target single battery is stored in the form of a magnetic field. Taking the case where the battery non-dissipative equalization system detects that the energy of single battery B 1 is relatively high as an example, then single battery B 1 is the target single battery, close switching tube S 2 and switching tube S 3 , so that the target single battery, that is, single battery B 1 forms a closed loop with the secondary coil of transformer T 1 , and transfer the energy of the target single battery such as single battery B1 to the secondary coil of transformer T 1 for storage. Subsequently, close switching tube S 1 , transfer the energy stored in the secondary coil of transformer T 1 to the primary coil of transformer T 1 . The primary coil of transformer T 1 forms a closed loop with the low-voltage vehicle-mounted power supply (i.e., vehicle-mounted power supply E) to supply power to the low-voltage vehicle-mounted battery (i.e., vehicle-mounted power supply E) in reverse. When the target single battery such as single battery B 1 releases energy to reach the set balanced state, then disconnect switching tube S1 、Switching transistor S 2 、Switching transistor S 3 ,The target single cell, such as single cell B 1 Equalization completed.

[0084] In some embodiments, when the energy of any single cell in the battery pack exceeds the set energy range, it further includes: when the energy of any single cell in the battery pack is lower than the lower limit of the set energy range.

[0085] In step S120, when the energy of any single cell in the battery pack exceeds the set energy range, controlling the switch of the switch unit and controlling the selection unit to select this single cell in the battery pack further includes: a second control process of controlling the switch unit and the selection unit when the energy of any single cell in the battery pack is lower than the lower limit of the set energy range.

[0086] Next, in combination with Figure 5 The schematic flowchart of an embodiment of controlling the switch unit and the selection unit when the energy of any single cell in the battery pack is lower than the lower limit of the set energy range in the method of the present invention shown, further illustrating the specific process of controlling the switch unit and the selection unit when the energy of any single cell in the battery pack is lower than the lower limit of the set energy range, including: step S310 to step S330.

[0087] Step S310, when the energy of any single cell in the battery pack is lower than the lower limit of the set energy range, controlling the switch unit to turn on so that the primary coil of the transformer forms a closed loop with the storage battery, and partially transferring the energy of the storage battery to the primary coil of the transformer and storing it.

[0088] Step S320, controlling the selection unit to select this single cell in the battery pack so that a closed loop is formed between this single cell in the battery pack and the secondary winding of the transformer, transferring the energy stored in the primary winding of the transformer to the secondary coil of the transformer, and transferring the energy obtained in the secondary coil of the transformer to this single cell in the battery pack.

[0089] Step S330: When the energy of the single battery in the battery pack is released to the second set energy, that is, when the energy of the single battery in the battery pack is replenished to the set balanced state, control the switch unit to disconnect, so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and control the selection unit to cancel the selection of the single battery in the battery pack, so as to disconnect the closed loop formed between the single battery in the battery pack and the secondary winding of the transformer.

[0090] Specifically, when the battery non-dissipative equalization system detects that the energy of the target single battery is too low, taking single battery B 2 as an example, first close the switch tube S 1 , the low-voltage storage battery (i.e., the vehicle-mounted power supply E) discharges, and transfers a part of the energy of the low-voltage storage battery (i.e., the vehicle-mounted power supply E) to the primary coil of the transformer T 1 . Subsequently, close the switch tube S 4 and the switch tube S 5 . The energy of the primary coil of the transformer T 1 is transferred to the secondary coil of the transformer T 1 . At the same time, the target single battery such as single battery B 2 forms a closed loop with the secondary coil of the transformer T 1 . The energy in the secondary coil of the transformer T 1 is transferred to the target single battery such as single battery B 2 , and charges the lower target single battery such as single battery B 2 . When the equalization operation is completed, then disconnect the switch tube S 1 , the switch tube S 4 , and the switch tube S 5 .

[0091] Thus, by using a switch tube such as a MOS tube to select the target single battery to be connected to the transformer, and through the charge and discharge function of the battery pack, the bidirectional energy transfer between the low-voltage storage battery and the power battery pack is realized, so that any battery in the power battery pack reaches the balanced state. The entire system only needs to use one transformer to perform charge and discharge operations on all target batteries, realizing the equalization of the battery system, reducing the number of transformers, and greatly reducing the cost.

[0092] Since the processing and functions implemented by the method of this embodiment are basically corresponding to the foregoing embodiments, principles and examples of the vehicle, for the details not described in the description of this embodiment, reference may be made to the relevant descriptions in the foregoing embodiments, and details will not be repeated here.

[0093] After a large number of experimental verifications, by adopting the technical solution of this embodiment, a transformer is arranged between the vehicle-mounted power supply and the battery pack, and switching tubes are arranged between the secondary coil of the transformer and the positive and negative electrodes of each single battery in the battery pack. Through the control of the switching tubes, the transformer is connected to the target single battery to realize bidirectional energy transfer. One transformer can cover the charge and discharge control of multiple single batteries, reducing the number of transformers and effectively reducing the cost.

[0094] In summary, it is easy for those skilled in the art to understand that on the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0095] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A control device for a battery equalization system, characterized in that, the battery equalization system includes: a storage battery, a switch unit, a transformer, a selection unit and a battery pack; the switch unit is arranged between the storage battery and the primary winding of the transformer; the selection unit is arranged between the secondary winding of the transformer and the battery pack; the control device for the battery equalization system includes: a detection unit and a control unit; wherein, the detection unit is configured to detect whether the energy of any single battery in the battery pack exceeds a set energy range; the control unit is configured to, when the energy of any single battery in the battery pack exceeds the set energy range, control the switch of the switch unit and control the selection unit to select the single battery in the battery pack to achieve energy equalization between the single battery and the storage battery; by arranging a transformer between the vehicle-mounted power supply and the battery pack, and arranging switching tubes between the secondary coil of the transformer and the positive and negative electrodes of each single battery in the battery pack, the conduction of the switching tubes is used to select the target single battery to be connected to the transformer, realizing bidirectional energy transfer and making any battery in the battery pack reach an equalized state.

2. The control device for the battery equalization system according to claim 1, characterized in that, the switch unit includes: a first switch module; the selection unit includes: a second switch module to a (2n + 1)-th switch module; the battery pack includes: a first single battery and an n-th single battery, where n is a positive integer; wherein, the first switch module is arranged between the positive electrode of the storage battery and one end of the primary winding of the transformer; the first single battery to the n-th single battery are connected in series; among the first single battery to the n-th single battery, the positive electrode of each single battery is connected to the first end of the secondary winding of the transformer through one of the switch modules from the second switch module to the (2n + 1)-th switch module; the negative electrode of each single battery is connected to the second end of the secondary winding of the transformer through another one of the switch modules from the second switch module to the (2n + 1)-th switch module.

3. The control device for the battery equalization system according to claim 2, characterized in that, any one of the first switch module, the second switch module to the (2n + 1)-th switch module includes: a switching tube.

4. The control device for the battery equalization system according to any one of claims 1 to 3, characterized in that, the situation that the energy of any single battery in the battery pack exceeds the set energy range includes: the situation that the energy of any single battery in the battery pack is higher than the upper limit of the set energy range; the control unit, when the energy of any single battery in the battery pack exceeds the set energy range, controls the switch of the switch unit and controls the selection unit to select the single battery in the battery pack, including: When the energy of any single battery in the battery pack is higher than the upper limit of the set energy range, control the selection unit to select the single battery in the battery pack, so as to form a closed loop between the single battery in the battery pack and the secondary winding of the transformer, and partially transfer and store the energy of the single battery in the battery pack to the secondary winding of the transformer; Control the switch unit to be turned on, so as to form a closed loop between the primary coil of the transformer and the storage battery, transfer the energy stored in the secondary winding of the transformer to the primary coil of the transformer, and reverse power supply to the storage battery through the energy obtained in the primary coil of the transformer; When the energy of the single battery in the battery pack is released to the first set energy, control the switch unit to be turned off, so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and control the selection unit to cancel the selection of the single battery in the battery pack, so as to disconnect the closed loop formed between the single battery in the battery pack and the secondary winding of the transformer.

5. The control device of the battery equalization system according to any one of claims 1 to 3, characterized in that, When the energy of any single battery in the battery pack exceeds the set energy range, it also includes: when the energy of any single battery in the battery pack is lower than the lower limit of the set energy range; The control unit, when the energy of any single battery in the battery pack exceeds the set energy range, controls the switch of the switch unit and controls the selection unit to select the single battery in the battery pack, and further includes: When the energy of any single battery in the battery pack is lower than the lower limit of the set energy range, control the switch unit to be turned on, so as to form a closed loop between the primary coil of the transformer and the storage battery, and partially transfer the energy of the storage battery to the primary coil of the transformer and store it; Control the selection unit to select the single battery in the battery pack, so as to form a closed loop between the single battery in the battery pack and the secondary winding of the transformer, transfer the energy stored in the primary winding of the transformer to the secondary coil of the transformer, and transfer the energy obtained in the secondary coil of the transformer to the single battery in the battery pack; When the energy of the single battery in the battery pack is released to the second set energy, control the switch unit to be turned off, so as to disconnect the closed loop formed between the storage battery and the primary coil of the transformer; and control the selection unit to cancel the selection of the single battery in the battery pack, so as to disconnect the closed loop formed between the single battery in the battery pack and the secondary winding of the transformer.

6. An automobile, characterized in that, comprising: The control device of the battery equalization system according to any one of claims 1 to 5.

7. A control method of a battery equalization system corresponding to the control device of the battery equalization system according to any one of claims 1 to 5, characterized in that, The battery equalization system includes: a storage battery, a switch unit, a transformer, a selection unit, and a battery pack; the switch unit is disposed between the storage battery and the primary winding of the transformer; the selection unit is disposed between the secondary winding of the transformer and the battery pack; The control method of the battery equalization system includes: Detecting whether the energy of any single battery in the battery pack exceeds a set energy range; When the energy of any single battery in the battery pack exceeds the set energy range, controlling the switch of the switch unit and controlling the selection unit to select the single battery in the battery pack to achieve energy equalization between the single battery and the storage battery; By setting a transformer between the vehicle power supply and the battery pack, and setting switching tubes between the secondary coil of the transformer and the positive and negative electrodes of each single battery in the battery pack, the conduction of the switching tubes is used to select the target single battery to be connected to the transformer, realizing bidirectional energy transfer and making any battery in the battery pack reach an equilibrium state.

8. The control method of the battery equalization system according to claim 7, wherein, The situation that the energy of any single battery in the battery pack exceeds the set energy range includes: the situation that the energy of any single battery in the battery pack is higher than the upper limit of the set energy range; When the energy of any single battery in the battery pack exceeds the set energy range, controlling the switch of the switch unit and controlling the selection unit to select the single battery in the battery pack includes: When the energy of any single battery in the battery pack is higher than the upper limit of the set energy range, controlling the selection unit to select the single battery in the battery pack to form a closed loop between the single battery in the battery pack and the secondary winding of the transformer, and partially transmitting and storing the energy of the single battery in the battery pack to the secondary winding of the transformer; Controlling the switch unit to be turned on so that the primary coil of the transformer and the storage battery form a closed loop, transferring the energy stored in the secondary winding of the transformer to the primary coil of the transformer, and reversely supplying power to the storage battery through the energy obtained in the primary coil of the transformer; When the energy of the single battery in the battery pack is released to the first set energy, controlling the switch unit to be turned off so that the closed loop formed between the storage battery and the primary coil of the transformer is disconnected; and controlling the selection unit to cancel the selection of the single battery in the battery pack so that the closed loop formed between the single battery in the battery pack and the secondary winding of the transformer is disconnected.

9. The control method of the battery equalization system according to claim 7, wherein, The situation that the energy of any single battery in the battery pack exceeds the set energy range further includes: the situation that the energy of any single battery in the battery pack is lower than the lower limit of the set energy range; In the case that the energy of any single battery in the battery pack exceeds the set energy range, control the switch of the switch unit, and control the selection unit to select the single battery in the battery pack. It further includes: In the case that the energy of any single battery in the battery pack is lower than the lower limit of the set energy range, control the switch unit to be turned on so that the primary coil of the transformer forms a closed loop with the storage battery, and partially transfer the energy of the storage battery to the primary coil of the transformer and store it; Control the selection unit to select the single battery in the battery pack so that a closed loop is formed between the single battery in the battery pack and the secondary winding of the transformer, transfer the energy stored in the primary winding of the transformer to the secondary coil of the transformer, and transfer the energy obtained in the secondary coil of the transformer to the single battery in the battery pack; In the case that the energy of the single battery in the battery pack is released to the second set energy, control the switch unit to be turned off so that the closed loop formed between the storage battery and the primary coil of the transformer is disconnected; and control the selection unit to cancel the selection of the single battery in the battery pack so that the closed loop formed between the single battery in the battery pack and the secondary winding of the transformer is disconnected.

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