Electric power-assisted bicycle power supply module and electric power-assisted bicycle

Abstract

The invention discloses an electric power-assisted bicycle power supply module, and belongs to the technical field of electric power-assisted bicycles, the electric power-assisted bicycle power supply module comprises a battery, a battery management system, a charging system and a connecting circuit, the battery management system is composed of a monitoring unit, a control unit, a protection unit and a communication unit, and the monitoring unit is used for monitoring the voltage, current and temperature of the battery; the control unit can control the charging and discharging process of the battery according to the information, such as the voltage, the current and the temperature, provided by the monitoring unit, of the battery, the protection unit can protect the battery in the charging and discharging process of the battery, the communication unit is used for information transmission among the sub-modules, and the charging system is composed of a charging interface and a charger. The connecting line is composed of an internal connecting line and an external connecting line. According to the power supply module of the electric power-assisted bicycle, a battery management system is optimized, the service life of a battery is prolonged, meanwhile, assistance is provided in the riding process, and the speed of the electric power-assisted bicycle is increased more easily.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric-assisted bicycles, and in particular relates to an electric-assisted bicycle power supply module and an electric-assisted bicycle. Background Art

[0002] An electric-assisted bicycle is a mechatronic personal transportation vehicle that uses a battery as an auxiliary energy source and is based on an ordinary bicycle and is equipped with a motor, controller, battery, handlebar and other operating components and a display instrument system.

[0003] Currently, the battery capacity of electric assisted bicycles is relatively small. Although assisted riding can save physical energy to a certain extent, due to the small capacity of the battery and the insufficient optimization of the battery management system of the power supply module, the capacity of the battery will gradually decay after multiple charge and discharge cycles, resulting in a shortened cruising range. Eventually, the battery needs to be replaced, which increases the cost of use. Summary of the invention

[0004] The purpose of the present invention is to provide an electric assisted bicycle power supply module and an electric assisted bicycle to solve the problem that the battery management system of the power supply module proposed in the above background technology is not optimized enough. After multiple charge and discharge cycles, the capacity of the battery will gradually decay, resulting in a shortened cruising range, and ultimately the battery needs to be replaced, which increases the cost of use.

[0005] The first aspect provides an electric assisted bicycle power supply module, including a battery, a battery management system, a charging system and a connecting line. The battery management system is composed of a monitoring unit, a control unit, a protection unit and a communication unit. The monitoring unit is used to monitor the voltage, current and temperature of the battery. The control unit will control the charging and discharging process of the battery according to the information such as the battery voltage, current and temperature provided by the monitoring unit. The protection unit can protect the battery during the charging and discharging process. The communication unit is used for information transmission between various submodules. The charging system is composed of a charging interface and a charger. The connecting line is composed of an internal connecting line and an external connecting line.

[0006] In a further embodiment, the monitoring unit includes a voltage monitoring module, a current monitoring module and a temperature monitoring module. A high-precision voltage sensor is used to measure the potential difference across the battery. The battery current is monitored by connecting a high-precision current sensor in series in the battery's charge and discharge circuit. This sensor can be a Hall effect-based current sensor or a shunt resistor current sensor. A temperature sensor is used to detect the surface temperature or internal temperature of the battery.

[0007] In a further embodiment, the control unit includes a charge and discharge control module and a balancing control module, which controls the charge and discharge process of the battery according to the battery voltage, current, temperature and other information provided by the monitoring unit. The balancing control module has two modes: active balancing and passive balancing. The active balancing method usually transfers the energy of a single cell with high power to a single cell with low power through a complex circuit. The passive balancing method is to connect a resistor in parallel to each single cell. When the voltage of a single cell is too high, the resistor is turned on to discharge it, so that the voltage of each single cell is balanced.

[0008] In a further embodiment, the protection unit includes an overshoot protection module, an overdischarge protection module and a short circuit protection module, and the communication unit consists of an internal communication module and an external communication module.

[0009] In a further embodiment, internal connecting wires are installed inside the battery pack, and the battery cells are connected in series or in parallel through the connecting wires to achieve the required voltage and capacity. These connecting wires need to have good conductivity and insulation.

[0010] A second aspect provides an electric-assisted bicycle, comprising the power supply module provided in the first aspect, wherein the power supply module is arranged on a frame of the electric-assisted bicycle.

[0011] Technical effects and advantages of the present invention: The electric-assisted bicycle power supply module and the electric-assisted bicycle can monitor the battery status, such as power, voltage, temperature, etc., in real time by setting a monitoring unit, a control unit, a protection unit and a communication unit in a battery management system, and perform accurate charge and discharge control to extend the battery life. In addition, the remaining battery life is predicted by an intelligent algorithm and transmitted through a communication module to provide more accurate information for the rider. Through the charge and discharge control module and the balancing control module in the control unit, the energy in the high-energy battery cell is transferred to the low-energy battery cell, so that the charge in the battery PACK is redistributed, thereby shortening the charging time and extending the discharge time. The electric power-assisted bicycle power supply module and the electric power-assisted bicycle optimize the battery management system, increase the service life of the battery, and provide assistance during riding, making it easier to increase the speed of the electric power-assisted bicycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a structural block diagram of the power supply module of the electric-assisted bicycle of the present invention; Figure 2 It is a schematic structural diagram of the electric power-assisted bicycle of the present invention. DETAILED DESCRIPTION

[0014] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0015] Unless otherwise defined, the up, down, left, right, front, back, inside and outside directions involved in this document are based on the up, down, left, right, front, back, inside and outside directions in the figures shown in the present invention, and are explained here together. Example

[0016] The present invention provides Figure 1 The power supply module of an electric-assisted bicycle shown in the figure includes a battery, a battery management system, a charging system and a connecting line. The battery management system is composed of a monitoring unit, a control unit, a protection unit and a communication unit. The battery is composed of a plurality of lithium battery packs. The monitoring unit is used to monitor the voltage, current and temperature of the battery. The control unit will charge and discharge the battery according to the information such as the battery voltage, current and temperature provided by the monitoring unit. The protection unit can protect the battery during the charging and discharging process. The communication unit is used for information transmission between various submodules. The monitoring unit includes a voltage monitoring module, a current monitoring module and a temperature monitoring module. The voltage monitoring module is mainly responsible for real-time monitoring of the voltage of each single cell in the battery pack. Usually, a high-precision voltage sensor is used. The sensor can accurately measure the potential difference between the two ends of the battery. For example, in a battery pack composed of multiple lithium battery cells, the voltage monitoring module will be connected to each single cell through a dedicated connection line to obtain their voltage values. Since the voltage range of lithium batteries is relatively narrow, the charging cut-off voltage is generally around 4.2-4.25V, and the discharging cut-off voltage is around 2.5-2.7V, so the voltage monitoring module needs to have a higher accuracy, and the general error range is within a few millivolts, so as to accurately judge the battery status and avoid overcharging or over-discharging; The current monitoring module is used to measure the charge and discharge current of the battery. It is achieved by connecting a high-precision current sensor in series in the battery's charge and discharge circuit. This sensor can be a current sensor based on the Hall effect or a shunt resistor current sensor. For example, the Hall effect current sensor uses the change of the magnetic field to measure the current. It has the advantages of high accuracy and fast response. By monitoring the current, the battery management system can control the battery's charge and discharge process to prevent excessive current from causing damage to the battery. At the same time, the remaining battery power can also be estimated based on the integral of the current. The temperature of the battery has a great influence on its performance and life, so the temperature monitoring module is indispensable. It generally uses a temperature sensor to detect the surface temperature or internal temperature of the battery. Common temperature sensors include thermistors and thermocouples. The resistance value of thermistors will change significantly with the change of temperature. The temperature can be calculated by measuring the change of its resistance value. Thermocouples measure temperature based on the thermoelectric effect of two different metals. The temperature monitoring module will feed back the battery temperature information to the control unit of the battery management system so that corresponding measures can be taken when the temperature is abnormal, such as reducing the charging or discharging current at high temperature and limiting the output power of the battery at low temperature. The control unit includes a charge and discharge control module and a balance control module. The charge and discharge process of the battery is controlled according to the battery voltage, current, temperature and other information provided by the monitoring unit. During the charging process, when the battery voltage reaches the preset charge cut-off voltage or the charging current exceeds the safety limit, the charge and discharge control module will cut off the charging circuit to prevent the battery from overcharging. For example, for a 36V lithium battery pack, when the total voltage reaches about 42V (taking into account the voltage upper limit of the single cell and the series connection of the battery pack), the charge and discharge control module will automatically stop charging. During the discharge process, when the battery voltage drops to the discharge cut-off voltage or the battery temperature is too high or too low, it will limit the power output of loads such as motors or cut off the discharge circuit to avoid over-discharge of the battery. Since the cells in the battery pack inevitably have differences in capacity, internal resistance, etc., the voltage and power of the cells will be unbalanced during the charging and discharging process. The role of the balancing control module is to solve this problem. The balancing control module has two modes: active balancing and passive balancing. The active balancing mode usually transfers the energy of the cells with high power to the cells with low power through a complex circuit. The passive balancing mode is to connect a resistor in parallel to each cell. When the voltage of a cell is too high, the resistor is turned on to discharge it, so that the voltage of each cell is balanced. The protection unit includes an overcharge protection module, an over-discharge protection module and a short-circuit protection module. The overcharge protection module closely monitors the battery voltage during the charging process. Once it finds that the battery voltage exceeds the preset overcharge protection threshold, it will take immediate action. Generally speaking, it will cut off the charging current by controlling the switching element (such as MOSFET) in the charging circuit. At the same time, it will also send out an alarm signal to notify the rider or other related systems (such as the display system) that the battery is overcharged. For example, during the charging process of the lithium battery, if the voltage monitoring module detects that the single cell voltage reaches 4.2-4.25V, the overcharge protection module will be activated to ensure the safety of the battery. The over-discharge protection module is mainly used to prevent the battery from over-discharging. During the discharge process, when the battery voltage drops to the preset over-discharge protection threshold, the over-discharge protection module will limit or cut off the discharge of the battery. It will also use the switch element to control the discharge circuit. For example, for lithium battery cells, when the voltage drops to 2.5-2.7V, the over-discharge protection module may cut off the discharge circuit to avoid irreversible damage such as battery plate sulfation and extend the battery life. The short-circuit protection module can respond instantly when the positive and negative electrodes of the battery are accidentally short-circuited. When a short circuit occurs, the current in the battery circuit will increase sharply. The short-circuit protection module will quickly detect this abnormal current change and protect the battery by quickly cutting off the circuit. Generally, a fuse or electronic switch with fast response characteristics (such as high-speed MOSFET) is used. This fast circuit cutting action is usually in microseconds, which can effectively prevent the battery from being damaged by a short circuit and avoid possible safety accidents. The communication unit consists of an internal communication module and an external communication module. The internal communication module is mainly used for information transmission between various sub-modules within the battery management system. For example, the monitoring unit transmits the collected voltage, current, temperature and other data to the control unit and the protection unit. It can use a variety of communication methods, such as SPI (Serial Peripheral Interface), I2C (Internal Integrated Circuit), etc. The SPI communication method has the characteristics of high speed and full-duplex, and is suitable for use in situations where the data transmission volume is large and the real-time requirements are high; the I2C communication method is relatively simple, occupies fewer pin resources, and is suitable for connecting multiple low-speed devices. Through the internal communication module, the battery management system can efficiently coordinate the work of each sub-module to ensure the normal operation of the system; The external communication module is responsible for the communication between the battery management system and external devices (such as the controller and display system of the electric bicycle). It can send the battery status information (such as the remaining power, voltage, temperature, etc.) to the external device, and can also receive the instructions of the external device. Common external communication methods include CAN (Controller Area Network) communication and UART (Universal Asynchronous Receiver / Transmitter) communication. CAN communication is a communication method with high reliability and strong anti-interference ability, which is widely used in the fields of automobile and industrial control; UART communication is relatively simple and low-cost, and is suitable for transmitting some simple instructions and data. Through the external communication module, BMS can better cooperate with other components to provide better user experience for riders; The charging system consists of a charging port and a charger. There are various types of charging ports for electric-assisted bicycles, including round ports and square ports. The design of the port must ensure good electrical connection and waterproof performance. Waterproof performance is particularly important because electric-assisted bicycles are used outdoors and may encounter rain and other situations. If water enters the charging port, it may damage the battery or cause safety problems such as short circuits. The output voltage and current of the charger must match the specifications of the battery. For example, for a 36V battery, a charger with an output voltage of about 36V is required. The charger generally has an indicator light to show the charging status, such as a red light indicating charging and a green light indicating charging is complete. At the same time, in order to improve charging efficiency and safety, modern chargers also have some protection functions, such as short circuit protection, overcurrent protection, etc. The connecting lines are composed of internal connecting lines and external connecting lines. The internal connecting lines are installed inside the battery pack. The battery cells are connected in series or in parallel through the connecting lines to achieve the required voltage and capacity. These connecting lines need to have good conductivity and insulation. For example, high-quality copper wires are used, and the outside is wrapped with insulating rubber or plastic materials to prevent short circuits between battery cells.

[0017] The connecting wires between the battery and the motor, controller and other electronic devices are used to transmit electrical energy and signals. These connecting wires must be able to withstand a certain current and be able to adapt to the vibration and bending of the bicycle during driving. Generally, wires with protective covers are used to improve their durability and anti-interference ability. Example

[0018] The present invention provides Figure 2 An electric assisted bicycle is shown, comprising a power supply module provided in the above embodiment, wherein the power supply module is arranged on the frame of the electric assisted bicycle, and a protective shell fixedly connected to the frame is installed on the outside of the power supply module, thereby providing comprehensive protection for the power supply module. At the same time, a display screen can be installed on the handlebars for displaying information about the battery module and the vehicle.

[0019] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. Machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The control method of the present invention is controlled by a controller, and the control circuit of the controller can be realized by simple programming by technicians in this field. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0020] In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 the present invention.

[0021] Working principle: The battery management system of the electric-assisted bicycle power supply module and the electric-assisted bicycle is responsible for monitoring the status of the battery, including parameters such as voltage, current, and temperature, to prevent the battery from being overcharged, over-discharged, overheated, etc., to ensure the safe use of the battery and extend the battery life. When the rider starts the electric-assisted bicycle and needs power assistance, the battery management system will output the stored electrical energy to the motor according to the instructions of the controller, provide power to the motor, and thus drive the bicycle forward.

[0022] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electric power-assisted bicycle power supply module, comprising a battery, a battery management system, a charging system and a connecting line, characterized in that: The battery management system consists of a monitoring unit, a control unit, a protection unit and a communication unit. The monitoring unit is used to monitor the voltage, current and temperature of the battery. The control unit will control the battery charging and discharging process according to the battery voltage, current and temperature information provided by the monitoring unit. The protection unit can protect the battery during the charging and discharging process. The communication unit is used to transmit information between each sub-module. The charging system consists of a charging interface and a charger. The connection line consists of internal connecting wires and external connecting wires.

2. An electric power supply module for an electric bicycle according to claim 1, characterized in that: The monitoring unit includes a voltage monitoring module, a current monitoring module and a temperature monitoring module. A high-precision voltage sensor is used to measure the potential difference between the two ends of the battery. A high-precision current sensor is connected in series in the battery's charge and discharge circuit to monitor the battery current. This sensor can be a Hall effect-based current sensor or a shunt resistor current sensor. A temperature sensor is used to detect the surface temperature or internal temperature of the battery.

3. An electric power supply module for an electric bicycle according to claim 1, characterized in that: The control unit includes a charge and discharge control module and a balancing control module. It controls the charge and discharge process of the battery according to the battery voltage, current, temperature and other information provided by the monitoring unit. The balancing control module has two modes: active balancing and passive balancing. The active balancing method usually transfers the energy of a single cell with high power to a single cell with low power through a complex circuit. The passive balancing method is to connect a resistor in parallel to each single cell. When the voltage of a single cell is too high, the resistor is turned on to discharge it, so that the voltage of each single cell is balanced.

4. A power supply module for an electric-assisted bicycle according to claim 1, characterized in that: The protection unit includes an overcharge protection module, an over-discharge protection module and a short-circuit protection module, and the communication unit consists of an internal communication module and an external communication module.

5. The power supply module for an electric-assisted bicycle according to claim 1, characterized in that: Internal connecting wires are installed inside the battery pack. The battery cells are connected in series or in parallel through connecting wires to achieve the required voltage and capacity. These connecting wires need to have good conductivity and insulation.

6. An electric power-assisted bicycle, characterized in that: It comprises the power supply module described in any one of claims 1 to 5, and the power supply module is arranged at the frame position of the electric-assisted bicycle.

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