Portable energy storage system and charging method thereof

Abstract

The invention discloses a portable energy storage system and a charging method thereof, the portable energy storage system comprises a main bag and at least one power-up bag connected in parallel with the main bag, and the main bag controls the power-up bag to charge and discharge; each of the main pack and the power-up pack comprises a battery cell module, a battery management system and a capacity expansion interface; the battery management system comprises a charging branch and a charging and discharging branch; the positive electrode of the battery cell module is electrically connected with the first end of the capacity expansion interface through the electricity supplementing branch; the positive electrode of the battery cell module is also electrically connected with the first end of the capacity expansion interface through the charging and discharging branch; the main pack is electrically connected with the adjacent power-up pack through the capacity expansion interface, and the adjacent power-up pack is electrically connected with the capacity expansion interface; on the basis that the residual capacity of the battery cell module of the main pack is smaller than a first threshold value, the charging and discharging branch circuit of the power-up pack and the charging branch circuit of the main pack are controlled to be conducted, and the power-up pack charges the battery cell module of the main pack through the charging and discharging branch circuit of the power-up pack and the charging branch circuit of the main pack in sequence. According to the technical scheme provided by the invention, the power-up bag is provided for realizing safe power supplementation for the main bag.

Description

Technical Field

[0001] This invention relates to the field of portable energy storage technology, and in particular to a portable energy storage system and its power replenishment method. Background Technology

[0002] With social development and the continuous improvement of people's living standards, portable energy storage now perfectly meets people's short-distance travel needs, leading to its increasing popularity and a growing demand for more refined portable products.

[0003] However, the capacity of existing portable energy storage systems cannot meet the growing electricity demand of users, so large-capacity energy storage systems are imperative. Summary of the Invention

[0004] This invention provides a portable energy storage system and its power replenishment method, which uses a power pack as the main package to achieve safe power replenishment.

[0005] In a first aspect, embodiments of the present invention provide a portable energy storage system, comprising: a main pack and at least one power pack connected in parallel with the main pack, wherein the main pack controls the charging and discharging of the power pack;

[0006] Both the main pack and the charging pack include a cell module, a battery management system, and an expansion interface; the battery management system includes a charging branch and a charging / discharging branch; the positive terminal of the cell module is electrically connected to the first end of the expansion interface through the charging branch; the positive terminal of the cell module is also electrically connected to the first end of the expansion interface through the charging / discharging branch; the main pack is electrically connected to the adjacent charging pack, and the adjacent charging pack is also electrically connected through the expansion interface;

[0007] Based on the fact that the remaining capacity of the battery module in the main package is less than a first threshold, the charging and discharging branch of the power supply pack and the power replenishment branch of the main package are controlled to be turned on, and the power supply pack replenishes the battery module of the main package in sequence through the charging and discharging branch of the power supply pack and the power replenishment branch of the main package.

[0008] Secondly, embodiments of the present invention also provide a method for replenishing power to a portable energy storage system, applicable to the portable energy storage system provided in any embodiment of the present invention, comprising:

[0009] When the remaining capacity of the main package's cell module is less than a first threshold, the main package controls the charging and discharging branch of the power-up package to be turned on, and controls the replenishment branch of the main package to be turned on, so that the current output by the cell module of the power-up package is transmitted to the cell module of the main package in sequence through the charging and discharging branch of the power-up package and the replenishment branch of the main package.

[0010] In this invention, the portable energy storage system includes a main pack and at least one power pack connected in parallel. Both the main pack and the power pack include cell modules, a battery management system, and an expansion interface. The battery management system includes a charging / discharging branch and a replenishment branch. The cell module includes a positive electrode and a negative electrode. The expansion interface includes a first terminal and a second terminal. The positive electrode is connected to the first terminal via the charging / discharging branch and also via the replenishment branch. Current is transferred between the main pack and adjacent power packs, as well as between two adjacent power packs, through the expansion interface. In this embodiment, when the portable energy storage system needs replenishment (when the remaining charge of the cell module in the main pack is less than a first threshold), the replenishment branch of the main pack is activated, and the charging / discharging branch of the power pack is activated, so that the cell module of the power pack replenishes the cell module of the main pack. Therefore, in the case of undervoltage in the main pack, the replenishment branch, capable of withstanding the full voltage difference between the main pack and the power pack, enables rapid and safe replenishment of the main pack, ensuring normal system operation even under undervoltage conditions and improving efficiency. Attached Figure Description

[0011] Figure 1 A schematic diagram of a portable energy storage system provided for the implementation of this invention;

[0012] Figure 2 This is a schematic diagram of another portable energy storage system provided in an embodiment of the present invention;

[0013] Figure 3 A schematic flowchart illustrating a method for replenishing power to a portable energy storage system provided in an embodiment of the present invention;

[0014] Figure 4 A schematic flowchart illustrating another method for replenishing power to a portable energy storage system provided in an embodiment of the present invention;

[0015] Figure 5 This is a schematic flowchart illustrating another method for replenishing power to a portable energy storage system provided in an embodiment of the present invention. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0017] Figure 1 A schematic diagram of a portable energy storage system provided for implementation of the present invention. Figure 2 This is a schematic diagram of another portable energy storage system provided in an embodiment of the present invention. The present invention provides a portable energy storage system, including: a main pack 12 and at least one power pack 13 connected in parallel with the main pack 12; the main pack 12 controls the charging and discharging of the power pack 13;

[0018] Both the main pack 12 and the charging pack 13 include a cell module 111, a battery management system 112, and an expansion interface 113. The battery management system 112 includes a charging branch 24 and a charging / discharging branch 22. The positive terminal of the cell module 111 is electrically connected to the first terminal P+ of the expansion interface 113 through the charging branch 24. The positive terminal of the cell module 111 is also electrically connected to the first terminal P+ of the expansion interface 113 through the charging / discharging branch 22. The main pack 12 is electrically connected to the adjacent charging pack 13, and the adjacent charging pack 13 is electrically connected through the expansion interface 113.

[0019] Based on the fact that the remaining capacity of the battery module 111 of the main package 12 is less than or equal to the first threshold, the charging and discharging branch 22 of the power supply package 13 and the replenishment branch 24 of the main package 12 are controlled to be turned on. The power supply package 13 is used to replenish the battery module 111 of the main package 12 with power through the replenishment branch 24 of the power supply package 13 and the replenishment branch 24 of the main package 12 in sequence.

[0020] In this embodiment, the portable energy storage system includes a main pack 12 and at least one power pack 13. The main pack 12 and power pack 13 have expansion capabilities. For example, the main pack 12 is connected to the power pack 13 via an expansion interface 113, and another power pack 13 is connected to the main pack 13 via the expansion interface 113. Optionally, the main pack 12 can also expand the capacity of its motherboard via the expansion interface 113. In this embodiment, the power pack 11 can be a high-voltage device. For example, in the prior art, the main pack is a 2 kWh product. In this embodiment, to further meet people's outdoor and home needs, the main pack 12 and power pack 13 can be products that can provide 5 kWh of electricity. In this embodiment, the number of power packs 13 can be one or more, for example, such as... Figure 1 As shown, one main package 12 is connected to five power-on packages 13; as Figure 2 As shown, a main package 12 is connected to one power-on package 13. The main package 12 and all power-on packages 13 are connected in parallel. The main package 12 and the power-on packages 13, as well as two adjacent power-on packages 13, are electrically connected through expansion interfaces (first expansion interface 114 and second expansion interface 115).

[0021] refer to Figure 1 and Figure 2Both the main package 12 and the power supply package 13 include a cell module 111, a battery management system (BMS) 112, and an expansion interface 113. The cell module 111 is electrically connected to the battery management system 112; the battery management system 112 is electrically connected to the expansion interface 113. The cell module 111 includes multiple individual cells connected in series and / or parallel for storing electrical energy. The battery management system 112 can monitor various parameters of the cell module 111 (current, voltage, remaining capacity, etc.) and control the operating status (output current, charging current) of the cell module 111. The battery management system 112 includes a charging branch 24 and a charging / discharging branch 21. The positive terminal of the cell module 111 is electrically connected to the first terminal P+ of the expansion interface 113 through the charging / discharging branch 21, and the positive terminal of the cell module 111 is electrically connected to the first terminal P+ of the expansion interface 113 through the charging branch 24. Optionally, the battery management system 112 may also include a sampling resistor 22. The negative terminal of the cell module 111 is electrically connected to the second terminal P- of the expansion interface 113 through the sampling resistor 22 to realize a current transmission loop. Figure 1 As shown, although the connection between the main pack 12 and the charging pack 13 appears to be series, the cell modules 111 of the main pack 12 and each charging pack 13 are actually connected in parallel, allowing current transfer between the main pack 12 and any one of the charging packs 13. It's important to note that the total voltage of the main pack 12 is its output voltage; the total voltage of the charging pack 13 is its output voltage. While both the main pack 12 and the charging pack 13 include cell modules 111, a battery management system (BMS) 112, and an expansion interface 113, there are some differences between them. The main pack 12 may also include an AC inverter and a DC converter. The AC inverter can output AC power for the load, and the DC converter can output DC power for the load. The power pack 13 is equivalent to an external battery module of the main pack 12, which is used to provide a large amount of power to the main pack 12 to meet people's increasing power demand.

[0022] There is a situation where the main battery pack 12 has just finished discharging and reached the undervoltage threshold, while the power supply pack 13 may have a SOC (State of Charge) of 100%, 50%, or even 20%. In this undervoltage situation, if the main battery pack 12 shuts down, the entire system will not function. Therefore, the power supply pack 13 needs to replenish power to the main battery pack 12 for it to operate. A diagram illustrating the power replenishment process is shown below. Figure 2As shown. When the main package 12 needs additional power, for example, when the remaining capacity of the battery module 111 of the main package 12 is less than a first threshold, the main package 12 controls the opening of the power supply branch 24 of the main package 12. The power supply package 13 draws power from the battery module 111 of the power supply package 13, passes through the charging and discharging branch 21 of the power supply package 13 to the expansion terminal 113, and then passes through the power supply branch 24 of the main package 12 to supply power to the main package, ensuring that the power supply current is greater than the current consumed by the main package 12 during normal operation, so that the battery module 111 of the main package 12 can quickly rise to the platform voltage. Optionally, the above-mentioned first threshold can be zero, that is, when the remaining capacity of the battery module 111 of the main package 12 is zero, the main package 12 controls the opening of the power supply branch 24 of the main package 12 and controls the conduction of the charging and discharging branch 21 of the power supply package 13 to conduct the power supply path and supply power to the main package 12.

[0023] Because there is a voltage difference between the main package 12 and the power supply package 13, for example, the main package 12 is allowed to be recharged when the total voltage is 63V, while the power supply package 13 may be fully charged at 126V. This results in a very large voltage difference between the power supply package 13 and the main package 12. This embodiment can adjust the impedance and conduction mode of the power supply package 24 to allow it to withstand the full voltage difference range between the main package and the power supply package (in the above example, the full voltage difference can be 63V), enabling rapid and safe recharging of the main package. This ensures that the system continues to operate normally even under undervoltage conditions, improving work efficiency.

[0024] In this embodiment of the invention, the portable energy storage system includes a main pack and at least one power pack connected in parallel. Both the main pack and the power pack include cell modules, a battery management system, and an expansion interface. The battery management system includes a charging / discharging branch and a replenishment branch. The cell module includes a positive electrode and a negative electrode. The expansion interface includes a first terminal and a second terminal. The positive electrode is connected to the first terminal via the charging / discharging branch, and also to the first terminal via the replenishment branch. Current is transferred between the main pack and adjacent power packs, as well as between two adjacent power packs, through the expansion interface. In this embodiment, when the portable energy storage system needs replenishment (when the remaining charge of the cell module in the main pack is less than a first threshold), the replenishment branch of the main pack is activated, and the charging / discharging branch of the power pack is activated, so that the cell module of the power pack replenishes the cell module of the main pack. Therefore, in the case of undervoltage in the main pack, the replenishment branch, capable of withstanding the full voltage difference between the main pack and the power pack, enables rapid and safe replenishment of the main pack, ensuring normal system operation even under undervoltage conditions and improving efficiency.

[0025] The above is the core idea of ​​this invention. The technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0026] Continue to refer to Figure 2 Optionally, the charging branch 24 may include a charging resistor 241 and a charging control module 242; the positive terminal of the cell module 111 is connected to the first terminal P+ of the expansion interface 113 via the charging resistor 241 and the charging control module 242; the charging and discharging branch 22 includes a switching transistor 221; the positive terminal of the cell module 111 is connected to the first terminal P+ of the expansion interface 113 via the switching transistor 221; the battery management system 112 is used to control the on or off state of the charging control module 242; the battery management system 112 is also used to control the on or off state of the switching transistor 221. In this embodiment, both the charging branch 24 and the charging and discharging branch 22 can be turned on or off under the control of the battery management system 112. In this embodiment, the power supply branch 24 may include a power supply resistor 241 and a power supply control module 242 connected in series, and the charging and discharging branch 21 may include a switching transistor 211. For example, the power supply resistor 241 may be a cement resistor, and the switching transistor 211 may be a MOS transistor.

[0027] Continue to refer to Figure 1 Optionally, there can be multiple power packs 13; the main pack 12 includes a first expansion interface 114; the power pack 13 includes a first expansion interface 114 and a second expansion interface 115; the first terminal P+ of the first expansion interface 114 is electrically connected to the first terminal P+ of the second expansion interface 115; the second terminal P- of the first expansion interface 114 is electrically connected to the second terminal P- of the second expansion interface 115; the first expansion interface 114 of the main pack 12 is electrically connected to the second expansion interface 115 of the adjacent power pack 13; the first expansion interface 114 of the power pack 13 is electrically connected to the second expansion interface 115 of the adjacent power pack 13. Multiple power packs 13 effectively increase the power storage capacity, further enhancing the power supply capability of the portable energy storage system, meeting the needs of both low-power outdoor devices and high-power household devices, thus adapting to people's ever-increasing electricity demand.

[0028] Optionally, the main package 12 and the power-on package 13 are electrically connected via the expansion bus 23; adjacent power-on packages 13 can also be electrically connected via the expansion bus 23. The expansion bus 23 includes a main return line harness and a low-voltage control harness. The main return line harness is used to transmit the current between the main package 12 and the power-on package 13; the low-voltage control harness is used to transmit control signals between the main package 12 and the power-on package 13. The control signals include at least the addressing and communication signals of the power-on package 13. The expansion bus 23 may include a main return line harness and a low-voltage control harness. The main return line harness mainly loads the main circuit, which is the high-current circuit supplied to the load by each power-on package 13 after passing through the MOSFET and fuse, i.e., the circuit between P+ and P-. The low-voltage control harness is used to transmit control signals and various parameters, and it mainly realizes the addressing and CAN communication functions of each power-on package 13. When all the power packs 13 are connected in parallel and successfully programmed, when the main pack 12 needs to be recharged, the main pack 12 controls the power recharge branch 24 of the main pack 12 to open. The power pack 13 draws power through the battery cell, passes through the MOS transistor and sampling resistor 22 of the power pack 13 to reach the expansion terminal 113, and then passes through the power recharge resistor 241 and power recharge control circuit 242 of the main pack 11 to recharge the main pack 12.

[0029] Optional, the maximum power handling capacity of the 241-channel supplementary resistor. Where U1 is the undervoltage threshold of the main transformer 12; U2 is the full-charge voltage of the power supply transformer 13; and R is the resistance of the supplementary resistor 241. The main transformer 12 can be supplemented at a total voltage of 63V, while the power supply transformer 13 may be fully charged at 126V. This results in a very large voltage difference between the power supply transformer 13 and the main transformer 12. Furthermore, the supplementary resistor 241 must also be compatible with the pre-discharge function and provide rapid supplementary charging. This limits the resistance of the supplementary resistor 241 to a very high value, typically around 50R. Therefore, the power handled by the supplementary resistor 241 will reach (126-63). 2 / 50 = 79.38W. This type of cement resistor has a very large volume, while the space on a BMS board is limited. Therefore, this embodiment reduces the impedance of the supplementary resistor 241 by adjusting the duty cycle of the supplementary power supply branch 24, thereby reducing the space occupied by the supplementary resistor 241 on the MS board. This maintains the supplementary power supply branch 24's ability to withstand the full voltage difference between the main package 12 and the power supply package 13, ensuring the power supply package 13 safely supplies power to the main package 12. Specifically, the maximum power handling capacity of the supplementary resistor 241 can be set. The maximum withstand power W is related to the undervoltage threshold U1 of the main package 12, the full voltage U2 of the power supply package 13, and the resistance R of the supplementary resistor 241. This can reduce the resistance of the supplementary resistor 241 while ensuring that the supplementary resistor 241 can withstand the full voltage difference range between the main package 12 and the power supply package 13 by adjusting the duty cycle, thus ensuring the safety performance of the supplementary power supply.

[0030] Based on the same concept, embodiments of the present invention also provide a method for replenishing power to a portable energy storage system. Figure 3 This is a schematic flowchart of a power replenishment method for a portable energy storage system provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the method in this embodiment includes the following steps:

[0031] Step S101: When the remaining capacity of the main package's cell module is less than or equal to the first threshold, the main package controls the charging and discharging branch of the power supply package to be turned on, and controls the main package's supplementary power supply branch to be turned on, so that the current output by the cell module of the power supply package is transmitted to the cell module of the main package in sequence through the charging and discharging branch of the power supply package and the supplementary power supply branch of the main package.

[0032] In this embodiment of the invention, the portable energy storage system includes a main pack and at least one power pack connected in parallel. Both the main pack and the power pack include cell modules, a battery management system, and an expansion interface. The battery management system includes a charging / discharging branch and a replenishment branch. The cell module includes a positive electrode and a negative electrode. The expansion interface includes a first terminal and a second terminal. The positive electrode is connected to the first terminal via the charging / discharging branch, and also to the first terminal via the replenishment branch. Current is transferred between the main pack and adjacent power packs, as well as between two adjacent power packs, through the expansion interface. In this embodiment, when the portable energy storage system needs replenishment (when the remaining charge of the cell module in the main pack is less than a first threshold), the replenishment branch of the main pack is activated, and the charging / discharging branch of the power pack is activated, so that the cell module of the power pack replenishes the cell module of the main pack. Therefore, in the case of undervoltage in the main pack, the replenishment branch, capable of withstanding the full voltage difference between the main pack and the power pack, enables rapid and safe replenishment of the main pack, ensuring normal system operation even under undervoltage conditions and improving efficiency.

[0033] Based on the above embodiments, the first threshold can be zero; the power replenishment method specifically includes: when the remaining power of the main package's cell module is zero, determining that the main package needs power replenishment, and controlling the power replenishment branch of the main package to be turned on. It should be noted that the main package branch is only turned on when the remaining power of the main package's cell module is zero, so that the power supply package can replenish the main package; when the remaining power of the main package's cell module is not zero, the power replenishment branch of the main package is turned off. During the power replenishment process, the main package stops supplying power to external AC or DC equipment.

[0034] Optionally, the portable energy storage system for which the charging method of this embodiment is applicable may further include a charging resistor and a charging control module; the positive terminal of the cell module is electrically connected to the first end of the expansion interface in sequence through the charging resistor and the charging control module; the charging and discharging branch includes a switching transistor; the positive terminal of the cell module is electrically connected to the first end of the expansion interface through the switching transistor; the battery management system is used to control the on or off of the charging control module; the battery management system is also used to control the on or off of the switching transistor. In this embodiment, as... Figure 4As shown, Figure 4 A schematic flowchart of another method for replenishing power to a portable energy storage system provided in an embodiment of the present invention is shown below. Figure 4 As shown, the method in this embodiment includes the following steps:

[0035] Step S201: When the remaining power of the battery cell module of the power pack is less than the first power threshold, control the switching transistor of the power pack to conduct with a 100% duty cycle.

[0036] When the residual current of the main battery module is zero, the main battery's charging branch is opened, activating the charging function. Additionally, the remaining charge of the charging battery module needs to be determined. If the remaining charge of the charging battery module is less than a first charge threshold, it indicates that the voltage difference between the main battery and the charging battery is small and will not exceed the charging resistor's tolerance. Therefore, the charging battery's switching transistor can be controlled to conduct stably at 100% duty cycle. Optionally, the first charge threshold can be 10%.

[0037] Step S202: When the remaining power of the battery cell module of the power pack is greater than or equal to the first power threshold, the duty cycle of the switching transistor of the power pack is controlled according to the range of the voltage difference between the total voltage of the power pack and the total voltage of the main pack.

[0038] When the remaining charge of the battery module in the power pack reaches the first charge threshold, the voltage difference between the total voltage of the power pack and the total voltage of the main pack is large, which may exceed the capacity of the charging circuit. To protect the charging branch, the duty cycle of the power pack's switching transistor can be adjusted according to the range of the voltage difference between the total voltage of the power pack and the main pack to avoid damage to the charging branch caused by excessive voltage difference.

[0039] Optionally, controlling the duty cycle of the switching transistor of the power supply unit based on the voltage difference range between the total voltage of the power supply unit and the total voltage of the main unit can include: when the voltage difference between the total voltage of the power supply unit and the total voltage of the main unit is within a first voltage difference range, controlling the switching transistor of the power supply unit to conduct with a 100% duty cycle; when the voltage difference between the total voltage of the power supply unit and the total voltage of the main unit is within a second voltage difference range, controlling the switching transistor of the power supply unit to conduct with a first duty cycle; when the voltage difference between the total voltage of the power supply unit and the total voltage of the main unit is within a third voltage difference range, controlling the switching transistor of the power supply unit to conduct with a second duty cycle; the third voltage difference range is higher than the second voltage difference range; the second voltage difference range is higher than the first voltage difference range; the first duty cycle is greater than the second duty cycle; the first duty cycle is less than 100% duty cycle. In this embodiment, with the supplementary power supply branch conducting, when the voltage difference between the total voltage of the power supply package and the total voltage of the main package is small, the duty cycle of the power supply package's switching transistor is controlled to be large; when the voltage difference between the total voltage of the power supply package and the main package is large, the duty cycle of the power supply package's switching transistor is controlled to be small. This effectively improves the supplementary power supply branch's ability to withstand voltage differences and enhances the safety of the power supply package supplementing the main package. Optionally, the first duty cycle is 50%, and the second duty cycle is 30%.

[0040] Optionally, if the undervoltage threshold U1 of the main package 12 is 63V and the full-voltage U2 of the power supply package 13 is 126V, the total voltage difference is 63V. Accordingly, the first voltage difference range U0 corresponding to a 100% duty cycle can be set within U0≤25V; the second voltage difference range U1 corresponding to a 50% duty cycle can be set between 25V<U1≤40V; and the third voltage difference range U2 corresponding to a 30% duty cycle can be set between 40V<U2≤63V. The supplementary resistor used in this embodiment can operate stably when the voltage difference U0≤25V, can operate with a larger duty cycle when 25V<U1≤40V, and can operate with a smaller duty cycle when 40V<U2≤63V, thereby ensuring the normal and stable operation of the supplementary power system and improving system reliability.

[0041] like Figure 5 As shown, Figure 5 The following is a flowchart illustrating another method for replenishing power in a portable energy storage system provided in an embodiment of the present invention. The complete process of replenishing power is described in detail with specific examples: First, it is determined whether the remaining power of the main unit is zero; if not, the replenishing branch of the main unit is shut down to disable its replenishing function; if not, the main unit needs to stop transmitting power to the outside and connect the replenishing control module to enable the replenishing function.

[0042] After activating the power replenishment function, the system continues to determine whether the voltage difference between the total voltage of the power supply unit and the total voltage of the main unit is within the first voltage difference range U0. If so, the power supply unit's switching transistor is controlled to conduct with a 100% duty cycle. If the voltage difference between the power supply unit and the main unit's total voltage is not within the first voltage difference range U0, the system continues to determine whether the voltage difference between the power supply unit and the main unit's total voltage is within the second voltage difference range U1. If so, the power supply unit's switching transistor is controlled to conduct with a first duty cycle of 50%. If the voltage difference between the power supply unit and the main unit's total voltage is not within the second voltage difference range U1, the system continues to determine whether the voltage difference between the power supply unit and the main unit's total voltage is within the third voltage difference range U2. If so, the power supply unit's switching transistor is controlled to conduct with a second duty cycle of 30%. This embodiment effectively adjusts the duty cycle of the power supply unit's switching transistor based on the range of the voltage difference between the power supply unit and the main unit's total voltage, improving the safety of the main unit's power replenishment.

[0043] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A portable energy storage system, characterized in that, include: A main package and at least one power pack connected in parallel with the main package, wherein the main package controls the charging and discharging of the power pack; Both the main pack and the charging pack include a cell module, a battery management system, and an expansion interface; the battery management system includes a charging branch and a charging / discharging branch; the positive terminal of the cell module is electrically connected to the first end of the expansion interface through the charging branch; the positive terminal of the cell module is also electrically connected to the first end of the expansion interface through the charging / discharging branch; the main pack is electrically connected to the adjacent charging pack, and the adjacent charging pack is also electrically connected through the expansion interface; Based on the fact that the remaining capacity of the battery module in the main package is less than or equal to a first threshold, the charging and discharging branch of the power supply package and the replenishment branch of the main package are controlled to be turned on, and the power supply package replenishes the battery module of the main package in sequence through the charging and discharging branch of the power supply package and the replenishment branch of the main package.

2. The portable energy storage system according to claim 1, characterized in that, The battery management system further includes a sampling resistor; the negative terminal of the cell module is electrically connected to the second terminal of the expansion interface through the sampling resistor.

3. The portable energy storage system according to claim 1, characterized in that, The power supply branch includes a power supply resistor and a power supply control module; the positive terminal of the battery cell module is electrically connected to the first end of the expansion interface in sequence through the power supply resistor and the power supply control module; The charging and discharging branch includes a switching transistor; the positive terminal of the battery cell module is electrically connected to the first end of the expansion interface through the switching transistor. The battery management system is used to control the on or off of the charging control module; the battery management system is also used to control the on or off of the switching transistor.

4. The portable energy storage system according to claim 1, characterized in that, The number of power-on packages is multiple; the main package includes a first expansion interface; the power-on package includes a first expansion interface and a second expansion interface; a first end of the first expansion interface is electrically connected to a first end of the second expansion interface; a second end of the first expansion interface is electrically connected to a second end of the second expansion interface. The first expansion interface of the main package is electrically connected to the second expansion interface of the adjacent power-on package; the first expansion interface of the power-on package is electrically connected to the second expansion interface of the adjacent power-on package.

5. The portable energy storage system according to claim 1, characterized in that, The main package is electrically connected to the adjacent power-on package via an expansion bus; adjacent power-on packages are electrically connected via an expansion bus. The expansion bus includes a main return line harness and a low-voltage control line harness; the main return line harness is used to transmit current between the main package and the power-on package; The low-voltage control harness is used to transmit control signals between the main package and the power-on package; the control signals include at least the addressing and communication signals of the power-on package.

6. The portable energy storage system according to claim 3, characterized in that, The maximum power handling capacity of the supplementary resistor Wherein, U1 is the undervoltage threshold of the main package's total voltage; U2 is the full-charge voltage of the power-on package's total voltage; and R is the resistance value of the supplementary resistor.

7. A method for replenishing power to a portable energy storage system, characterized in that, The portable energy storage system applicable to any one of claims 1-6 includes: When the remaining capacity of the main package's cell module is less than or equal to a first threshold, the main package controls the charging and discharging branch of the power-up package to be turned on, and controls the replenishment branch of the main package to be turned on, so that the current output by the cell module of the power-up package is transmitted to the cell module of the main package in sequence through the charging and discharging branch of the power-up package and the replenishment branch of the main package.

8. The method for replenishing power to a portable energy storage system according to claim 7, characterized in that, The first threshold is zero; The power replenishment method specifically includes: When the remaining power of the battery cell module in the main package is zero, the charging branch of the main package is turned on.

9. The method for replenishing power to a portable energy storage system according to claim 8, characterized in that, The charging branch includes a charging resistor and a charging control module; the positive terminal of the battery cell module is electrically connected to the first terminal of the expansion interface through the charging resistor and the charging control module in sequence; the charging and discharging branch includes a switching transistor; the positive terminal of the battery cell module is electrically connected to the first terminal of the expansion interface through the switching transistor; the battery management system is used to control the on or off of the charging control module; the battery management system is also used to control the on or off of the switching transistor; The power replenishment method further includes: When the remaining power of the battery cell module of the power pack is less than the first power threshold, the switch of the power pack is controlled to be turned on with a 100% duty cycle. When the remaining charge of the battery cell module of the power supply package is greater than or equal to the first charge threshold, the duty cycle of the switching transistor of the power supply package is controlled according to the range of the voltage difference between the total voltage of the power supply package and the total voltage of the main package.

10. The method for replenishing power to a portable energy storage system according to claim 9, characterized in that, The duty cycle of the switching transistor of the power supply is controlled according to the range of the voltage difference between the total voltage of the power supply and the total voltage of the main package, including: When the voltage difference between the total voltage of the power supply and the total voltage of the main package is within the first voltage difference range, the switching transistor of the power supply is controlled to be turned on with a 100% duty cycle. When the voltage difference between the total voltage of the power supply and the total voltage of the main package is within the second voltage difference range, the switching transistor of the power supply is controlled to conduct with a first duty cycle; When the voltage difference between the total voltage of the power supply and the total voltage of the main package is within the third voltage difference range, the switching transistor of the power supply is controlled to conduct with the second duty cycle. The third differential pressure range is higher than the second differential pressure range; the second differential pressure range is higher than the first differential pressure range; the first duty cycle is greater than the second duty cycle; the first duty cycle is less than 100% duty cycle.

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