A power supply for electric bicycles based on a distributed series topology

Abstract

This utility model discloses a power supply for electric bicycles based on a distributed series topology, comprising multiple lithium battery boxes connected in series. Each lithium battery box contains multiple lithium battery cells, with at least two lithium battery cells connected in parallel to form a lithium battery cell group, and at least two lithium battery cell groups connected in series. The multiple lithium battery boxes are connected by electrically connecting the positive terminal of one lithium battery box to the negative terminal of the next lithium battery box to form a total output circuit of the power supply. The series terminals of the multiple lithium battery boxes serve as the total positive output terminal and the total negative output terminal of the power supply, respectively, for powering the electric bicycle. This distributed series structure ultimately forms a high-voltage DC power supply that meets the requirements of the electric bicycle drive motor. This structure allows for flexible adjustment of the total output voltage by increasing or decreasing the number of lithium battery boxes. At the same time, the modular design facilitates quick replacement of specific lithium battery boxes in case of partial failure, significantly improving the reliability and maintenance convenience of the power supply system.

Description

Technical Field

[0001] This utility model relates to the field of electric bicycle power supply technology, and in particular to an electric bicycle power supply based on a distributed series topology. Background Technology

[0002] With the widespread use of electric bicycles in commuting, logistics, and other scenarios, lithium batteries have become the mainstream power source in the industry due to their advantages such as high energy density (generally above 200Wh / kg) and long cycle life (more than 2000 charge-discharge cycles). However, traditional single-cell integrated lithium battery systems have significant technical bottlenecks. For example, Chinese patent CN221379622U discloses a lithium battery for electric bicycles in which the main battery pack and the backup battery pack are integrated into one unit. The main battery pack serves as the power source for the electric bicycle in its daily use, while the backup battery pack serves as an auxiliary power source to provide emergency power and heating power for the heating film. The applicant of this utility model found that the overall packaging structure of the lithium battery in the above-mentioned prior art limits the expandability of the battery pack capacity and voltage, and users cannot flexibly adjust the energy configuration according to actual working conditions. When some lithium cells age or are damaged, the entire battery pack needs to be replaced, resulting in resource waste and a surge in maintenance costs. Therefore, with the "Safety Technical Specifications for Lithium-ion Battery for Electric Bicycles" putting forward clear requirements for battery maintainability, it is urgent to improve the system flexibility and sustainability through modular reconstruction. Utility Model Content

[0003] In view of the above-mentioned prior art, the present invention provides a power supply for electric bicycles based on a distributed series topology, which mainly solves the technical problems existing in the background art.

[0004] To achieve the above objectives, the technical solution of this utility model embodiment is implemented as follows:

[0005] An electric bicycle power supply based on a distributed series topology includes multiple lithium battery boxes connected in series.

[0006] Each lithium battery box contains multiple lithium battery cells, with at least two lithium battery cells connected in parallel to form a lithium battery cell group, and at least two lithium battery cell groups connected in series with each other.

[0007] The multiple lithium battery boxes are connected by electrically connecting the positive terminal of one lithium battery box to the negative terminal of the next lithium battery box to form a total output circuit of the power supply. The series connection ends of the multiple lithium battery boxes serve as the total positive output terminal and the total negative output terminal of the power supply, respectively, for powering electric bicycles.

[0008] Optionally, the negative terminal of the first lithium battery box is used as the total negative terminal output, and the positive terminal of the last lithium battery box is used as the total positive terminal output.

[0009] Optionally, multiple lithium battery cell groups are numbered sequentially from 1 to N, with the negative electrode of the lithium battery cell group numbered 1 serving as the negative output terminal of the lithium battery box, and the positive electrode of the lithium battery cell group numbered N serving as the positive output terminal of the lithium battery box.

[0010] Optionally, adjacent lithium battery cell groups can be directly electrically connected through the positive terminal of the previous lithium battery cell group to the negative terminal of the next lithium battery cell group.

[0011] Optionally, the positive terminals of all lithium-ion cells in each lithium-ion cell group are connected in parallel through a first conductor, and the negative terminals of all lithium-ion cells are connected in parallel through a second conductor. Any connection point on the first conductor serves as the positive output terminal of the lithium-ion cell group, and any connection point on the second conductor serves as the negative output terminal of the lithium-ion cell group.

[0012] Optionally, each lithium battery box is equipped with a protection device, which is electrically connected to the lithium battery cell assembly via a wire.

[0013] Optionally, the protection device is a protection circuit board, which is provided with a main control chip, an ADC module, a temperature detection circuit, a voltage detection circuit, and a current detection circuit. Multiple lithium battery cells are electrically connected to the temperature detection circuit, the voltage detection circuit, and the current detection circuit, respectively. The temperature detection circuit, the current detection circuit, and the voltage detection circuit are connected to the ADC module, and the output terminal of the ADC module is electrically connected to the main control chip.

[0014] Optionally, the protection circuit board is provided with a communication module and a display module. The main control chip is connected to the vehicle controller via the communication module, and the main control chip is electrically connected to the display module.

[0015] The beneficial effects of this utility model are as follows: The electric bicycle power supply based on a distributed series topology provided in this application has lithium battery cells connected in parallel within a lithium battery cell group to form a basic power supply unit, which increases the capacity of a single lithium battery cell group and reduces its internal resistance. Multiple lithium battery cell groups are arranged in series within a lithium battery box, and a boost unit is formed by directly connecting the positive terminal of the preceding lithium battery cell group to the negative terminal of the following lithium battery cell group, enabling a single lithium battery box to output a higher voltage. Multiple lithium battery boxes are further connected in a series configuration to form a total power supply circuit. The negative terminal of the first lithium battery box and the positive terminal of the last lithium battery box serve as the total power output terminals, respectively. Through this distributed series structure, a high-voltage DC power supply that meets the requirements of the electric bicycle drive motor is finally formed. This structure can flexibly adjust the total output voltage by increasing or decreasing the number of lithium battery boxes. At the same time, the modular design facilitates the quick replacement of specific lithium battery boxes in case of partial failure, significantly improving the reliability and maintenance convenience of the power supply system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal circuit connection of the lithium battery box in an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the circuit connection of the power supply for the electric bicycle in an embodiment of this application;

[0018] Figure 3 This is a schematic diagram of the connection of the protective circuit board in an embodiment of this application.

[0019] Explanation of icon numbers:

[0020] 1. Lithium battery box; 2. Lithium battery cell assembly; 3. Lithium battery cell; 4. Protection circuit board; 5. Main control chip; 6. ADC module; 7. Temperature detection circuit; 8. Voltage detection circuit; 9. Current detection circuit; 10. Communication module; 11. Display module. Detailed Implementation

[0021] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used in this specification of this utility model is for the purpose of describing particular embodiments only and is not intended to limit the utility model. In the following description, the expression "some embodiments" refers to a subset of all possible embodiments; however, it should be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0022] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0023] It should be understood that this invention can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. Furthermore, the terminology used herein is intended only to describe particular embodiments and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0024] It should also be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0025] To fully understand this utility model, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this utility model. Optional embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0026] Please refer to the attached document. Figures 1 to 3 This application provides a power supply for electric bicycles based on a distributed series topology, including multiple lithium battery boxes 1 connected in series.

[0027] Each lithium battery box 1 contains multiple lithium battery cells 3, with at least two lithium battery cells 3 connected in parallel to form a lithium battery cell group 2, and at least two lithium battery cell groups 2 connected in series with each other.

[0028] The multiple lithium battery boxes 1 are connected by electrically connecting the positive terminal of one lithium battery box 1 to the negative terminal of the next lithium battery box 1 to form a total output circuit of the power supply. The series terminals of the multiple lithium battery boxes 1 are respectively used as the total positive output terminal and the total negative output terminal of the power supply for powering electric bicycles. That is, the negative terminal of the first lithium battery box 1 is used as the total negative output terminal, and the positive terminal of the last lithium battery box 1 is used as the total positive output terminal.

[0029] Specifically, the lithium battery box 1 serves as a modular electric vehicle power supply unit. Each lithium battery box 1 contains multiple lithium battery cells 3. At least two lithium battery cells 3 are connected in parallel to form a lithium battery cell group 2, and at least two lithium battery cell groups 2 are connected in series. For example, one lithium battery box 1 contains four lithium battery cell groups 2, and one lithium battery cell group 2 contains nine lithium battery cells 3. The nine lithium battery cells 3 are connected in parallel, and the four lithium battery cell groups 2 are connected in series. The distributed series topology electric bicycle power supply disclosed in this application achieves efficient combination and output of electrical energy through a hierarchical structure. The lithium battery cells 3 are connected in parallel within the lithium battery cell group 2 to form a basic power supply unit, increasing the capacity of a single lithium battery cell group 2 and reducing its internal resistance. Multiple The lithium battery cells 2 are arranged in series within the lithium battery box 1. A boost unit is formed by directly connecting the positive terminal of the preceding lithium battery cell 2 to the negative terminal of the following lithium battery cell 2, enabling a single lithium battery box 1 to output a higher voltage. Multiple lithium battery boxes 1 are further connected in series to form a total power supply circuit. The negative terminal of the first lithium battery box 1 and the positive terminal of the last lithium battery box 1 serve as the total power output terminals, respectively. This distributed series structure ultimately forms a high-voltage DC power supply that meets the requirements of the electric bicycle drive motor. This structure allows for flexible adjustment of the total output voltage by increasing or decreasing the number of lithium battery boxes 1. At the same time, the modular design facilitates the quick replacement of specific lithium battery boxes 1 in case of partial failure, significantly improving the reliability and maintenance convenience of the power system.

[0030] Furthermore, the lithium battery cells 2 in each lithium battery box 1 are numbered sequentially from 1 to N, and the negative electrode of the lithium battery cell 2 numbered 1 serves as the negative output terminal of the lithium battery box 1, and the positive electrode of the lithium battery cell 2 numbered N serves as the positive output terminal of the lithium battery box 1. Adjacent lithium battery cell 2s are directly electrically connected through the positive electrode of the previous lithium battery cell 2 and the negative electrode of the next lithium battery cell 2.

[0031] Specifically, multiple lithium battery cell groups 2 within each lithium battery box 1 are connected in series according to their numbering order. The positive terminal of the previous lithium battery cell group 2 is directly electrically connected to the negative terminal of the next lithium battery cell group 2. The negative terminal of the first lithium battery cell group 2 serves as the negative output terminal of the lithium battery box 1, and the positive terminal of the last lithium battery cell group 2 serves as the positive output terminal of the lithium battery box 1. This allows the voltage within a single lithium battery box 1 to be increased through the series connection of lithium battery cell groups 2. When a new lithium battery cell group 2 with the number N+1 is added, the positive terminal of the original lithium battery cell group 2 with the number N is automatically switched to be connected to the negative terminal of the new unit. The positive terminal of the new unit then becomes the updated positive output terminal of the lithium battery box 1, achieving seamless connection in the expansion process.

[0032] Optionally, the positive terminals of all lithium battery cells 3 in each lithium battery cell group 2 are connected in parallel through a first conductor, and the negative terminals of all lithium battery cells 3 are connected in parallel through a second conductor. Any connection point on the first conductor serves as the positive output terminal of the lithium battery cell group 2, and any connection point on the second conductor serves as the negative output terminal of the lithium battery cell group 2.

[0033] Specifically, the parallel structure of lithium battery cells 3 collects the positive current through the first conductor and the negative current through the second conductor. The connection point of any conductor can be used as the positive and negative output terminals of the lithium battery cell group 2. This design allows for the asymmetrical distribution of lithium battery cells 3 without affecting the overall performance. Both the first conductor and the second conductor are made of low-melting-point metallic conductive materials.

[0034] Furthermore, the protection device is a protection circuit board 4, which is equipped with a main control chip 5, an ADC module 6, a temperature detection circuit 7, a voltage detection circuit 8, and a current detection circuit 9. Multiple lithium battery cell groups 2 are electrically connected to the temperature detection circuit 7, the voltage detection circuit 8, and the current detection circuit 9, respectively. The temperature detection circuit 7, the current detection circuit 9, and the voltage detection circuit 8 are connected to the ADC module 6, and the output terminal of the ADC module 6 is electrically connected to the main control chip 5.

[0035] In some embodiments, multiple lithium battery cell groups 2 are electrically connected to a temperature detection circuit 7, a voltage detection circuit 8, and a current detection circuit 9 respectively via signal acquisition lines. The signal acquisition lines include a first signal acquisition line, a second signal acquisition line, and a third signal acquisition line. The first signal acquisition line is connected to the voltage detection circuit 8, the second signal acquisition line is connected to the current detection circuit 9, and the third signal acquisition line is connected to the temperature detection circuit 7.

[0036] Specifically, the first signal acquisition line is connected to the voltage detection circuit 8, directly acquiring the voltage signals of each lithium battery cell group 2, providing basic data for overcharge and over-discharge protection and active balancing; the second signal acquisition line is connected to the current detection circuit 9, which uses a shunt resistor to detect the main circuit current and uses a differential amplifier to amplify the small voltage drop signal to the acquisition range of the ADC module 6, realizing real-time monitoring of the charging and discharging current, providing a basis for the main control chip 5 to judge the overcurrent or short circuit state; the third signal acquisition line is connected to the temperature detection circuit 7 and the NTC thermistor located at the center of the battery pack. Utilizing the characteristic that the resistance of the NTC thermistor changes with temperature, the temperature signal is converted into a voltage signal by the voltage divider circuit in the temperature detection circuit 7, and then converted by the ADC module 6 for analysis by the main control chip 5, realizing the monitoring of the temperature at key locations. Furthermore, the protection circuit board 4 is equipped with a communication module 10 and a display module 11. The main control chip 5 is connected to the on-board controller of the electric bicycle through the communication module 10, and the main control chip 5 is electrically connected to the display module 11.

[0037] Specifically, the main control chip 5 transmits the digital signals converted by the voltage detection circuit 8, current detection circuit 9, and temperature detection circuit 7 via the ADC module 6 to the vehicle controller via the communication module 10, which transmits data such as the battery pack's voltage, current, temperature, SOC, and fault codes. At the same time, the communication module 10 also receives parameter setting instructions sent by the vehicle controller and feeds them back to the main control chip 5 for configuration adjustment.

[0038] The display module 11 is directly electrically connected to the main control chip 5 to intuitively present the operating status of the battery pack. The main control chip 5 transmits the processed key information, such as the current voltage of the battery pack, the remaining power, the operating temperature, and fault warnings, to the display module 11 in the form of digital signals. The display module 11 converts this information into visual data and displays it to the user through LED indicators, digital tubes, or LCD screens.

[0039] It should be noted that the implementation of temperature detection circuit 7, voltage detection circuit 8, current detection circuit 9, communication module 10, and display module 11 are all common knowledge to those skilled in the art. For example, temperature detection circuit 7 uses the temperature-dependent characteristics of NTC thermistor to convert the temperature signal into a voltage signal using a voltage divider circuit for detection; voltage detection circuit 8 typically uses a high-precision ADC chip to sample and convert the battery voltage signal to analog-to-digital; current detection circuit 9 uses a shunt resistor to collect the voltage drop generated by the current, which is then differentially amplified and sent to the ADC for conversion; communication module 10 selects UART, CAN bus, Bluetooth, or Wi-Fi to achieve data transmission according to communication requirements; display module 11 uses LED indicators, digital tubes, or LCD screens, combined with the control signals output by the main control chip 5, to complete the status display. The above circuits and connection methods can all be implemented based on the common knowledge of those skilled in the art, and will not be specifically described in this embodiment.

[0040] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. The protection scope of this utility model should be determined by the protection scope of the stated claims.

Claims

1. A power supply for an electric bicycle based on a distributed series topology, characterized in that, Includes multiple lithium battery boxes connected in series. Each lithium battery box contains multiple lithium battery cells, with at least two lithium battery cells connected in parallel to form a lithium battery cell group, and at least two lithium battery cell groups connected in series with each other. The multiple lithium battery boxes are connected by electrically connecting the positive terminal of one lithium battery box to the negative terminal of the next lithium battery box to form a total output circuit of the power supply. The series connection ends of the multiple lithium battery boxes are respectively used as the total positive output terminal and the total negative output terminal of the power supply for powering electric bicycles. The positive terminals of all lithium-ion cells in each lithium-ion cell group are connected in parallel through a first conductor, and the negative terminals of all lithium-ion cells are connected in parallel through a second conductor. Any connection point on the first conductor serves as the positive output terminal of the lithium-ion cell group, and any connection point on the second conductor serves as the negative output terminal of the lithium-ion cell group. Each lithium battery box is equipped with a protection device, which is electrically connected to the lithium battery cell assembly via a wire. The protection device is a protection circuit board, which is equipped with a main control chip, an ADC module, a temperature detection circuit, a voltage detection circuit, and a current detection circuit. Multiple lithium battery cells are electrically connected to the temperature detection circuit, the voltage detection circuit, and the current detection circuit, respectively. The temperature detection circuit, the current detection circuit, and the voltage detection circuit are connected to the ADC module, and the output terminal of the ADC module is electrically connected to the main control chip. The protection circuit board is equipped with a communication module and a display module. The main control chip is connected to the vehicle controller via the communication module and is electrically connected to the display module.

2. The electric bicycle power supply based on a distributed series topology according to claim 1, characterized in that, The negative terminal of the first lithium battery box is used as the total negative terminal output, and the positive terminal of the last lithium battery box is used as the total positive terminal output.

3. A power supply for an electric bicycle based on a distributed series topology according to claim 1, characterized in that, Multiple lithium battery cell groups are numbered sequentially from 1 to N, with the negative electrode of lithium battery cell group numbered 1 serving as the negative output terminal of the lithium battery box, and the positive electrode of lithium battery cell group numbered N serving as the positive output terminal of the lithium battery box.

4. A power supply for an electric bicycle based on a distributed series topology according to claim 3, characterized in that, Adjacent lithium battery cell groups are directly electrically connected through the positive terminal of the previous lithium battery cell group and the negative terminal of the next lithium battery cell group.

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