Battery pack output control method, output control device, and energy storage device

Abstract

The application discloses a battery pack output control method, an output control device and an energy storage equipment. The battery pack comprises a plurality of battery modules. The battery pack is connected in series with all the battery modules through an electronic switch network, and at least one of the battery modules can be isolated from the battery pack through the electronic switch network. The output control method comprises the following steps: detecting the required power of an accessed load; when the required power is greater than or equal to a preset power, the series-connected battery pack is controlled to enter a high-voltage output mode; and when the required power is less than the preset power, the series-connected battery pack is controlled to enter a low-voltage output mode. The output control method of the battery pack can reduce the overall voltage of the battery pack, reduce unnecessary power loss, maintain voltage balance among the battery modules and has the advantages of simple control.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage batteries, and in particular to an output control method, an output control device, and an energy storage device for a battery pack. Background Art

[0002] To output a sinusoidal waveform comparable to mains electricity, mobile energy storage devices employ a two-stage circuit architecture consisting of a power factor correction (PFC) circuit and an LLC resonant converter. When the device is unloaded or extremely lightly loaded, the PFC and LLC circuits remain in standby mode to ensure immediate power supply after mounting. This results in power loss.

[0003] In order to reduce power loss, when the mobile energy storage device is unloaded or ultra-lightly loaded, the battery voltage of the mobile energy storage device can be lowered to reduce the circuit loss when the energy storage device is unloaded. However, when the battery voltage is lowered, the battery voltage will be inconsistent, resulting in battery damage. Summary of the Invention

[0004] The purpose of this application is to provide an output control method, an output control device and an energy storage device for a battery pack, aiming to solve the problem that mobile energy storage equipment suffers from power loss when it is unloaded or lightly loaded, and that when the battery voltage is reduced, the battery voltage is inconsistent, resulting in battery damage.

[0005] A first aspect of an embodiment of the present application provides an output control method for a battery pack, wherein the battery pack includes a plurality of battery modules, wherein the battery pack is connected in series via an electronic switch network, and at least one of the battery modules can be isolated from the battery pack via the electronic switch network. The output control method includes the following steps:

[0006] Detect the required power of the connected load;

[0007] When the required power is greater than or equal to the preset power, controlling the battery pack to enter a high voltage output mode;

[0008] When the required power is less than the preset power, controlling the battery pack to enter a low voltage output mode;

[0009] In the high-voltage output mode, all the battery modules in the battery pack are connected in series, and in the low-voltage output mode, the battery cells in the battery pack are isolated in turn, and the battery cells include at least one battery module.

[0010] In one embodiment, after controlling the battery pack to enter the high voltage output mode, the method further includes:

[0011] Continuously detect the required power;

[0012] When the required power is greater than or equal to the preset power, maintain the battery pack in the high-voltage output mode;

[0013] When the required power is lower than the preset power and lasts for a preset duration, control the battery pack to enter the low-voltage output mode.

[0014] In one embodiment, the control for the battery pack to enter the low-voltage output mode includes:

[0015] Control the electronic switch network to isolate the Nth battery module of the battery pack, and obtain the output power P of the battery pack N ;

[0016] When the output power P of the battery pack N is consistent with the preset output power, stop isolating the Nth battery module;

[0017] Control the electronic switch network to isolate the (N + 1)th battery module of the battery pack, where 0 < N < M - 1 and M is the number of battery modules in the battery pack.

[0018] In one embodiment, the control for the battery pack to enter the low-voltage output mode includes:

[0019] Control the electronic switch network to isolate the first battery module of the battery pack for a preset duration, and obtain the output power P1 of the battery pack within the preset duration;

[0020] Control the electronic switch network to isolate the Nth battery module of the battery pack, collect the output power Pn, and when Pn = P1, stop isolating the Nth battery module, N ≥ 2;

[0021] When a round of isolation of all the battery modules in the battery pack is completed, return to execute the step of isolating the battery modules of the battery pack in turn.

[0022] In one embodiment, before the step of returning to execute the step of isolating the battery modules of the battery pack in turn, it further includes:

[0023] Detect the required power;

[0024] The step of returning to execute the step of isolating the battery modules of the battery pack in turn includes:

[0025] When the required power is lower than the preset power, each battery module of the battery pack is isolated in turn, wherein, in the step of rotating isolation, the output power P1 is used as the preset power of the battery pack during the isolation of each battery module in a new round of isolation.

[0026] In one embodiment, the step of returning to execute isolating each battery module of the battery pack in turn includes:

[0027] Controlling the electronic switch network to isolate the first battery module of the battery pack for a second preset time, and collecting the output power P'1 of the battery pack during the second preset time;

[0028] The electronic switch network is controlled to isolate the Nth battery module of the battery pack and collect the output power P'n; when P'n=P1, the isolation of the Nth battery module is stopped.

[0029] A second aspect of an embodiment of the present application provides an output control device for a battery pack, wherein the battery pack includes a plurality of battery modules, each of which includes at least one battery connected in series. The output control device includes:

[0030] an electronic switch network for connecting all the battery modules in series and isolating at least one of the battery modules from the battery pack;

[0031] A detection unit, used to detect the load and determine whether the required power is greater than the preset power;

[0032] A control unit is used to control the battery pack to enter a high-voltage output mode when the required power is greater than or equal to the preset power, and to control the battery pack to enter a low-voltage output mode when the required power is lower than the preset power; wherein, in the high-voltage output mode, the control unit controls the electronic switch network so that all the battery modules in the battery pack are connected in series; in the low-voltage output mode, the control unit controls the electronic switch network so that each battery cell in the battery pack is isolated in turn, and the battery cell includes at least one battery module.

[0033] In one embodiment, the electronic switch network includes:

[0034] A plurality of series switches, respectively connected to the battery modules, for connecting the battery modules in series;

[0035] A plurality of isolation switches are respectively connected to each of the battery modules and are used to connect or disconnect the battery pack when isolating each of the battery modules individually.

[0036] In one embodiment, each of the series switches is connected in series between two adjacent battery modules;

[0037] The first end of each of the isolation switches is connected to one end of the corresponding battery module, and the second end of each of the isolation switches is commonly connected to the output of the battery pack.

[0038] A third aspect of the embodiments of the present application provides an energy storage device, which includes a battery pack and an output control device for the battery pack provided by the second aspect of the embodiments of the present application.

[0039] Compared with the prior art, the embodiments of the present application have the following beneficial effects: by detecting the power demand of the load connected to the battery pack, when the power demand of the load is greater than or equal to the preset power, the battery pack is controlled to enter a high-voltage output mode; when the power demand of the load is less than the preset power, the battery pack is controlled to enter a low-voltage output mode. In the high-voltage output mode, all battery modules in the battery pack are connected in series, and in the low-voltage output mode, each battery cell in the battery pack is isolated in turn, and the battery cell includes at least one battery module. The embodiments of the present application can control the battery pack of the mobile energy storage device to enter a low-voltage output mode when the mobile energy storage device is unloaded or lightly loaded, thereby reducing the problem of unnecessary power loss, and by controlling the isolation of each battery cell in turn, the voltage balance between the battery modules is maintained while reducing the power loss of the mobile energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A circuit diagram of a battery pack and an electronic switch network provided in one embodiment of the present application;

[0041] Figure 2 A flowchart of an output control method for a battery pack provided in one embodiment of the present application;

[0042] Figure 3 A flowchart of an output control method provided in another embodiment of the present application;

[0043] Figure 4 A schematic diagram of a process for a battery pack to enter a low voltage output mode according to an embodiment of the present application;

[0044] Figure 5 A schematic diagram of a flow chart of a battery pack entering a low voltage output mode according to another embodiment of the present application;

[0045] Figure 6 A specific flow chart of rotation isolation in a low voltage output mode provided by an embodiment of the present application;

[0046] Figure 7 A specific flowchart of rotation isolation in low voltage output mode provided by another embodiment of the present application;

[0047] Figure 8 This is a schematic structural diagram of a battery pack provided in a use example of this application;

[0048] Figure 9 A flowchart of a battery pack output control method provided in a use example of the present application;

[0049] Figure 10 A table showing the correspondence between the electronic switch status and the isolated battery module provided in a use case of this application;

[0050] Figure 11 A schematic diagram of the principle of an output control device provided in one embodiment of the present application;

[0051] Figure 12 A schematic diagram of the principle of an energy storage device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0053] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0054] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0056] See also Figure 1In a first aspect of an embodiment of the present application, a circuit diagram of a battery pack 100 and an electronic switch network 200 is provided. The battery pack 100 includes a plurality of battery modules, which may be a single energy storage battery or two or more energy storage batteries connected in parallel or in series to form a battery module. The battery pack 100 connects all battery modules in series through the electronic switch network 200, and can isolate at least one battery module from the battery pack 100 through the electronic switch network 200. Specifically, please refer to Figure 1 The battery pack 100 includes battery modules C1, C2...C n , where battery modules C1, C2…C n For a single energy storage battery, the electronic switch network 200 includes electronic switches K1, K2...K 2n , where battery modules C1, C2…C n Through the electronic switches K1, K3...K 2n-1 Connected in series, electronic switches K1, K2...K 2n The on and off of the electronic switch network 200 can be controlled. By controlling the electronic switch network 200, at least one battery module can be isolated from the battery pack 100, that is, the isolated battery module does not participate in the series connection of the battery pack 100. Figure 2 The output control method of the battery pack 100 includes the following steps:

[0057] S100: Detect the required power of the connected load.

[0058] Please combine Figure 1 As shown, the power requirement of the load connected to the output terminal of the battery pack 100 is detected. Here, the power requirement of the load is, for example, the power required for the normal operation of the load connected to the battery pack 100.

[0059] S200: When the required power is greater than or equal to the preset power, control the battery pack to enter a high voltage output mode.

[0060] Please combine Figure 1 As shown, when the power demand of the battery pack 100 is greater than or equal to the preset power, for example, the power demand of the load is greater than 10% of the maximum output power of the battery pack 100, the battery pack 100 is controlled to enter the high voltage output mode. The high voltage output mode here is achieved by controlling the electronic switches K1, K2...K 2n The battery modules C1, C2...C nAll participate in the series connection of the battery pack 100. It can be understood that the preset power can be set according to actual needs and is not a fixed value. In an embodiment of the present application, the preset power is 10% of the maximum output power of the battery pack 100. In other embodiments, the preset power can also be 20%, 30%, 50%, etc. of the maximum output power of the battery pack 100. In some embodiments, the preset power can also be 10%, 20% or other proportions of the rated output power of the output interface of the energy storage device including the battery pack 100. It should be further explained that the energy storage device includes the battery pack 100, and the energy storage device is provided with a plurality of output interfaces, which are directly or indirectly connected to the battery pack 100, and the rated output power or maximum output power of each output interface is different. When the output interface of the energy storage device into which the load is inserted is different, the value of the preset power is also different.

[0061] S300: When the required power is less than the preset power, the battery pack is controlled to enter a low voltage output mode.

[0062] Please combine Figure 1 As shown, when the load power requirement is less than the preset power, for example, when the load power requirement is less than 10% of the rated output power of the battery pack, the battery pack 100 is controlled to enter the low voltage output mode. The low voltage output mode is achieved by controlling the electronic switches K1, K2, ... 2n The battery modules C1, C2...C n One or more battery modules C1, C2...C n The battery module 100 is isolated in turn. For example, when the battery module C1 is isolated, the battery module C1 does not participate in the series connection of the battery pack 100, thereby reducing the output voltage of the battery pack 100. In this embodiment, in the low-voltage output mode, each electronic switch is controlled to isolate one battery module at a time. In other embodiments, one battery module can be used as a battery unit, or two or more battery modules can be connected in series to form a battery unit. In the low-voltage output mode, each electronic switch is controlled to isolate one battery unit at a time. Figure 1 In this embodiment, C1, C2...C n Represents a single battery module. Each battery module includes an energy storage battery. In low-voltage output mode, only one battery module is isolated at a time by controlling each electronic switch.

[0063] In a first aspect, an embodiment of the present application provides a method for controlling the output of a battery pack. The method comprises a battery pack 100 comprising a plurality of battery modules, wherein the battery pack 100 is connected in series via an electronic switch network 200 and is capable of isolating at least one battery module from the battery pack 100 via the electronic switch network 200. The method detects the power demand of a load connected to the battery pack 100 and controls the battery pack 100 to enter a high-voltage output mode when the load power demand is greater than or equal to a preset power; and controls the battery pack 100 to enter a low-voltage output mode when the load power demand is less than the preset power. The high-voltage output mode involves all battery modules in the battery pack 100 being connected in series, while the low-voltage output mode involves each battery cell in the battery pack 100 being isolated in turn, each battery cell comprising at least one battery module. When a mobile energy storage device comprising the battery pack 100 is unloaded or lightly loaded, the method controls the battery pack 100 to enter the low-voltage output mode, thereby reducing unnecessary power loss. Furthermore, by isolating each battery cell in turn, the battery pack 100 maintains voltage balance between the battery modules while reducing power loss in the mobile energy storage device, thereby resolving the problem of inconsistent battery voltages that can lead to battery damage. In the present application, each battery cell is isolated in turn, which means that in the isolation step of the battery pack, only one battery cell is isolated from the battery pack 100 at a time.

[0064] See also Figure 3 In one embodiment, after controlling the battery pack 100 to enter the high voltage output mode, that is, after step S200, the following steps are further included:

[0065] S400: Continuously detect the required power.

[0066] Please combine Figure 1 As shown, after the battery pack 100 enters high-voltage output mode, the operating status of its load may change. For example, the load may be turned off, causing the load power demand to fall below the preset power. If the battery pack 100 continues to operate in high-voltage output mode, unnecessary power loss will occur. Therefore, it is necessary to continuously monitor the load power demand of the battery pack 100.

[0067] S500: When the required power is greater than or equal to the preset power, the battery pack is maintained in a high voltage output mode.

[0068] Please combine Figure 1 As shown, after the battery pack 100 enters the high voltage output mode, if the power demand of the load is still greater than or equal to the preset power, the battery pack 100 maintains the high voltage output mode.

[0069] S600: When the required power is lower than the preset power and lasts for a preset time, control the battery pack to enter a low voltage output mode.

[0070] Please combine Figure 1 As shown, after the battery pack 100 enters the high-voltage output mode, its load changes, resulting in the demand power of the load being lower than the preset power and lasting for a preset duration. For example, when it is detected that the demand power of the load is lower than the preset power, the timing starts. If the demand power of the load remains lower than the preset power within 5 minutes, the battery pack 100 is controlled to enter the low-voltage output mode.

[0071] In this embodiment, after the battery pack 100 enters the high-voltage output mode, by continuously detecting the demand power of the load and controlling the battery pack 100 to enter the low-voltage output mode when the demand power of the load is lower than the preset power, the unnecessary power consumption of the battery pack 100 under light load or no load can be further reduced, saving power.

[0072] Please refer to Figure 4 , in one of the embodiments, controlling the battery pack 100 to enter the low-voltage output mode includes:

[0073] S301. Control the electronic switch network to isolate the Nth battery module of the battery pack and obtain the output power P of the battery pack N .

[0074] Please refer to Figure 1 As shown, by controlling the opening or closing of the electronic switches K1, K2...K in the electronic switch network 200 2n , the Nth battery module in the battery pack 100 is isolated, and the output power P of the battery pack 100 is obtained N .

[0075] S302. When the output power P of the battery pack N is consistent with the preset output power, stop isolating the Nth battery module.

[0076] In this step, when it is detected that the output power P of the battery pack 100 N is consistent with the preset output power, the electronic switch network 200 will be controlled to connect the Nth battery module to the battery pack 100 and stop isolation. Specifically, the preset output power is pre-set, and the preset output power can be determined according to the selection of each battery module in the battery pack 100.

[0077] S303. Control the electronic switch network to isolate the (N + 1)th battery module of the battery pack, where 0 < N < M - 1 and M is the number of battery modules in the battery pack.

[0078] Please refer to Figure 1 As shown, by controlling the electronic switches K1, K2...K in the electronic switch network 200 2nWhen turned on or off, the (N + 1)-th battery module in the battery pack 100 is isolated, where 0 < N < M - 1 and M is the number of battery modules in the battery pack 100.

[0079] In one embodiment, referring to Figure 1 , in the above steps S301 to S303, first isolate the first battery module C1 of the battery pack 100, disconnect the electronic switch K1, and close the electronic switches K2, K3, K5... K 2n-1 . The remaining electronic switches are disconnected. At this time, obtain the output power P N of the battery pack 100. As the isolation progresses, the power of other battery modules in the battery pack 100 is consumed. When the output power P N of the battery pack 100 is consistent with the preset output power, it is considered that the battery module C1 does not need to be further isolated. At this time, isolate the second battery module C2 of the battery pack 100, close the electronic switches K1, K2, and K3, and close the electronic switches K5 to K 2n-1 for connecting the battery modules in series. The remaining electronic switches are disconnected. It can be understood that the preset output power here can change with the change of the load.

[0080] Please refer to Figure 5 , in one embodiment, controlling the battery pack to enter the low-voltage output mode includes:

[0081] S310. Control the electronic switch network to isolate the first battery module of the battery pack for a preset duration, and obtain the output power P1 of the battery pack within the preset duration.

[0082] The preset duration here is, for example, 5 minutes. As shown in Figure 1 , within five minutes of isolating the battery module C1, the output power of the battery pack 100 is denoted as P1.

[0083] S320. Control the electronic switch network to isolate the N-th battery module of the battery pack, collect the output power Pn of the battery pack, and stop isolating the N-th battery module when Pn = P1, where N ≥ 2.

[0084] Combined with Figure 1 shown, isolate the N-th battery module of the battery pack 100, and at the same time collect the output power of the battery pack 100. For example, after finishing isolating the first battery module C1, the isolation of the second battery module, that is, the battery module C2, can be started, and the output power of the battery pack 100 is collected and denoted as P2. When P2 = P1, stop isolating the battery module C2. By maintaining the consistency of the output power of the battery pack 100 during the two isolation processes, the voltage balance between the battery modules in the battery pack 100 is maintained.

[0085] S330: After completing one round of isolation of all battery modules in the battery pack, return to the step of isolating each battery module of the battery pack in turn.

[0086] Combine Figure 1 As shown, after a complete round of isolation of all battery modules of the battery pack 100, a new round of isolation begins, that is, the battery modules in the battery pack 100 are isolated in turn. n After all are isolated, return to start a new round of battery modules C1, C2...C n Isolate in turn. It can be understood that the order of isolation in turn can be from C1 to C n , or in any order, as long as all battery modules are isolated in one round of isolation.

[0087] See also Figure 6 In one embodiment, before the above step S330, that is, before returning to the step of isolating each battery module of the battery pack in turn, the method further includes:

[0088] S331. Detect required power.

[0089] Before starting a new round of isolation, the load's required power is detected. Figure 1 , the step of returning to execute isolating each battery module of the battery pack 100 in turn specifically includes:

[0090] S332: When the required power is lower than the preset power, isolate the battery modules of the battery pack in turn.

[0091] In this step, when a new round of isolation is performed, the load's required power is first detected to ensure that the load's required power is lower than the preset power before a new round of isolation is performed. Figure 1 In the step of rotating isolation, the output power P1 in the previous round of isolation is used as the preset power of the battery pack 100 during the period when each battery module is isolated in the new round of isolation. The output power P1 in the previous round of isolation is used as the preset power in the new round of isolation to maintain the uniformity of the output power calculation, and there is no need to recalculate an output power as the preset power in each round of isolation. And the output power P1 in the first round of isolation is the output power of the battery pack 100 that actually works for a period of time, which is closer to reality and has a smaller error. It should be noted that in the present application, when the battery pack 100 is in low-voltage output mode, it is also necessary to detect the required power of the load. When the required power of the load is greater than the preset power, it is immediately switched to high-voltage output mode.

[0092] See also Figure 7In one embodiment, the step of returning to execute the step of isolating each battery module of the battery pack 100 in turn in step S330 includes:

[0093] S3301: Control the electronic switch network to isolate the first battery module of the battery pack for a second preset time, and collect the output power P'1 of the battery pack during the second preset time.

[0094] S3302: Control the electronic switch network to isolate the Nth battery module of the battery pack and collect the output power P'n; when P'n=P'1, stop isolating the Nth battery module.

[0095] In this embodiment, combined with Figure 1 As shown, in the step of returning to execute a new round of isolation to isolate each battery module in turn, the first battery module C1 of the battery pack 100 is isolated for a second preset duration, where the second preset duration is, for example, 3 minutes. During the 3-minute isolation of battery module C1, the output power of the battery pack 100 is recorded as P'1. The Nth battery module of the battery pack 100 is isolated, and the output power of the battery pack 100 is collected simultaneously. After the isolation of the first battery module C1 is completed, the second battery module, namely battery module C2, can be isolated, while the output power of the battery pack 100 is continuously collected, which is recorded as P'2. When P'2 = P'1, the isolation of battery module C2 is stopped. By maintaining the output power of the battery pack 100 consistent during the two isolation processes, the voltage balance of the battery modules in the battery pack 100 is maintained. In the new round of isolation in this embodiment, by redetermining the output power P'1 of the battery pack 100 when isolating the first battery module, the output power of the battery pack 100 within the shorter isolation preset time is used as the strategy basis for isolating the next battery module, thereby achieving more accurate isolation time control and further ensuring voltage balance between the battery modules of the battery pack 100.

[0096] In order to facilitate understanding of the steps of the output control method in the above embodiment, in one use case, please refer to Figure 8 is a schematic diagram of the battery pack 100, as shown in Figure 9 FIG. 1 is a flow chart showing an output control method of the battery pack 100 according to this example of use. Figure 10 The table shows the isolated battery modules corresponding to different switch control strategies of the electronic switch network 200 in this use case. Figure 8 、 9As shown in Figure 10, five groups of battery modules are connected in series to form a battery pack 100. The battery pack 100 generates a voltage of 5*5=25V when the voltage of each battery module is 5V. The battery module voltage will decrease as the battery power decreases. However, it can be seen from the previous description that in order to reduce the no-load loss, it is hoped that the voltage of the battery pack 100 can still maintain a voltage less than 25V, such as 20V, under the condition of maximum power. The battery module can be isolated from the battery pack 100 through the electronic switch network 200. When a lower voltage is required, it is only necessary to open the two switches next to one of the battery modules to isolate the battery module. For example, to isolate C1, it is necessary to disconnect K1 and close K2 (the other switches are in the default state: that is, disconnect K4, K6, K8, K9, etc. 10 , close K3, K5, K7, K9), at this time C1 is isolated and only C2-C5 are working, that is, maintaining a 20V voltage. Similarly, if you want to isolate the C2 battery, you need to close K2 and K4, and open K3 (the other switches are in the default state: that is, close K1, K3, K5, K7, K9, and open K6, K8, K9). 10 ), for more isolation strategies, please refer to Figure 10 , on means the electronic switch is disconnected, and off means the electronic switch is closed.

[0097] It can be understood that the voltage reduction of the battery pack 100 is only used under no-load or ultra-light-load conditions. When a load such as an electrical appliance is detected to be connected to the battery pack 100, it switches to the battery-free isolation mode to restore the normal battery operating voltage, preventing excessive load from putting too much pressure on the bus voltage, resulting in voltage drop, current increase, and overcurrent protection shutdown.

[0098] The output control method of the battery pack 100 in the above embodiment can reduce unnecessary power loss of the mobile energy storage device when it is unloaded or lightly loaded, maintain voltage balance between the battery modules, and avoid the problem of voltage unevenness caused by excessive isolation of battery modules.

[0099] A second aspect of the present invention provides an output control device 10 for a battery pack, wherein the battery pack includes a plurality of battery modules, each of which includes at least one battery connected in series. Figure 11The output control device 10 includes an electronic switch network 11, a detection unit 12, and a control unit 13. The electronic switch network 11 is used to connect all battery modules in series and to isolate at least one battery module from the battery pack. The detection unit 12 is used to detect the load and determine whether the required power is greater than the preset power. The control unit 13 is used to control the battery pack to enter a high-voltage output mode when the required power is greater than or equal to the preset power, and to control the battery pack to enter a low-voltage output mode when the required power is lower than the preset power. That is, the control unit 13 can control the opening and closing of each electronic switch of the electronic switch network 11; wherein, in the high-voltage output mode, the control unit 13 controls the electronic switch network 11 so that all battery modules in the battery pack are connected in series; in the low-voltage output mode, the control unit 13 controls the electronic switch network 11 so that each battery cell in the battery pack is isolated in turn, and the battery cell includes at least one battery module.

[0100] In one embodiment, see Figure 10 The electronic switch network 11 includes: a plurality of electronic switches K1, K3 ... K 2n-1 Respectively with each battery module C1, C2...C n Connection, used to connect the battery modules in series;

[0101] Multiple disconnect switches K2, K4...K 2n Respectively with each battery module C1, C2...C n Connections used to connect or disconnect the battery pack when isolating each battery module individually.

[0102] In one embodiment, see Figure 11 , each series switch K1, K3...K 2n-1 Respectively connected in series between two adjacent battery modules;

[0103] Each isolating switch K2, K4...K 2n The first end of each is connected to one end of the corresponding battery module, and each isolation switch K2, K4...K 2n The second ends of the batteries are connected in common and to the output of the battery pack.

[0104] See also Figure 12 A third aspect of the present invention provides an energy storage device, comprising the battery pack output control device 10 provided in the second aspect of the present invention. The energy storage device further comprises a memory storing a computer program that, when executed by a processor, implements the steps of the battery pack output control method described in each of the above embodiments.

[0105] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0106] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0107] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0108] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0109] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0110] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for controlling the output of a battery pack, characterized in that: The battery pack includes a plurality of battery modules. The battery pack connects all the battery modules in series through an electronic switch network and is capable of isolating at least one of the battery modules from the battery pack through the electronic switch network. The output control method includes the following steps: Detect the required power of the connected load; When the required power is greater than or equal to a preset power, control the battery pack to enter the high-voltage output mode; When the required power is less than the preset power, control the battery pack to enter the low-voltage output mode; The high-voltage output mode is that all the battery modules in the battery pack participate in the series connection, and the low-voltage output mode is that each battery unit in the battery pack is alternately isolated. The battery unit includes at least one of the battery modules; The control for the battery pack to enter the low-voltage output mode includes: Control the electronic switch network to isolate the Nth battery module of the battery pack and obtain the output power P of the battery pack N ; The output power P of the battery pack N When the output power is consistent with the preset value, the isolation of the Nth battery module is stopped; Control the electronic switch network to isolate the (N + 1)-th battery module of the battery pack, where 0 < N < M - 1 and M is the number of battery modules in the battery pack.

2. The output control method according to claim 1, wherein: After controlling the battery pack to enter the high-voltage output mode, it further includes: Continuously detect the required power; When the required power is greater than or equal to the preset power, maintain the battery pack in the high-voltage output mode; When the required power is lower than the preset power and lasts for a preset duration, control the battery pack to enter the low-voltage output mode.

3. The output control method according to claim 1 or 2, wherein: The control for the battery pack to enter the low-voltage output mode includes: Control the electronic switch network to isolate the first battery module of the battery pack for a preset duration, and obtain the output power P1 of the battery pack within the preset duration; Control the electronic switch network to isolate the N-th battery module of the battery pack, collect the output power Pn of the battery pack, and when Pn = P1, stop isolating the N-th battery module, where N ≥ 2; After completing one round of isolation of all the battery modules in the battery pack, return to execute the step of alternately isolating each battery module of the battery pack.

4. The output control method according to claim 3, wherein: Before returning to execute the step of alternately isolating each battery module of the battery pack, it further includes: Detect the required power; The return to execute the step of alternately isolating each battery module of the battery pack includes: When the required power is lower than the preset power, alternately isolate each battery module of the battery pack. In the step of alternate isolation, use the output power P1 as the preset power of the battery pack during the isolation of each battery module in the new round of isolation.

5. The output control method according to claim 3, wherein: The return to execute the step of alternately isolating each battery module of the battery pack includes: Control the electronic switch network to isolate the first battery module of the battery pack for a second preset duration, and collect the output power P'1 of the battery pack within the second preset time; Control the electronic switch network to isolate the N-th battery module of the battery pack, and collect the output power P'n; when P'n = P'1, stop isolating the N-th battery module.

6. An output control device for a battery pack, characterized in that: The battery pack includes a plurality of battery modules, and each battery module includes at least one battery connected in series. The output control device includes: An electronic switch network for connecting all battery modules in series and for isolating at least one of the battery modules from the battery pack; A detection unit for detecting a load and determining whether the required power is greater than a preset power; A control unit for controlling the battery pack to enter a high-voltage output mode when the required power is greater than or equal to the preset power, and for controlling the battery pack to enter a low-voltage output mode when the required power is lower than the preset power. In the high-voltage output mode, the control unit controls the electronic switch network to make all battery modules in the battery pack participate in the series connection. In the low-voltage output mode, the control unit controls the electronic switch network to alternately isolate each battery unit in the battery pack, and the battery unit includes at least one battery module; The control for the battery pack to enter the low-voltage output mode includes: Control the electronic switch network to isolate the Nth battery module of the battery pack and obtain the output power P of the battery pack N ; The output power P of the battery pack N When the output power is consistent with the preset value, the isolation of the Nth battery module is stopped; Controlling the electronic switch network to isolate the (N + 1)-th battery module of the battery pack, where 0 < N < M - 1 and M is the number of battery modules in the battery pack.

7. The output control device according to claim 6, wherein: The electronic switch network includes: A plurality of series switches respectively connected to each battery module for connecting each battery module in series; A plurality of isolation switches respectively connected to each battery module for conducting or disconnecting the connection to the battery pack when individually isolating each battery module.

8. The output control device according to claim 7, wherein: Each of the series switches is connected in series between two adjacent battery modules; The first end of each isolation switch is respectively connected to one end of the corresponding battery module, and the second ends of each isolation switch are commonly connected and connected to the output of the battery pack.

9. An energy storage device, characterized in that: Comprising a battery pack and an output control device according to any one of claims 6 - 8.

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