Electric bicycle battery system and electric bicycle

Abstract

The invention relates to an electric bicycle battery system (10) comprising: at least one battery cell (12) and a connector (16), the connector (16) and the at least one battery cell (12) being interconnected via an electrical power line (14); a sensor unit (20) for detecting a state value of the at least one battery unit (12); a controller (22) connected to the sensor unit (20) and configured to receive and evaluate the state value of the sensor unit (20); and a switch (18) arranged in the power line (14) for selectively establishing a connection between the connector (16) and the at least one battery cell (12); wherein the controller (22) is connected to the switch (18) and is configured to send a control signal (23) to the switch (18) for controlling the on-off of the switch (18).

Description

Technical Field

[0001] This invention relates to an electric bicycle battery system according to claim 1. The invention further relates to an electric bicycle having an electric bicycle battery system of this type according to claim 9, and a method for controlling an electric bicycle battery system according to claim 10. Background Technology

[0002] Bicycles with electric assist—also known as electric bicycles or electric-assisted bicycles (pedelecs)—are now widely popular and well-known. These electric bicycles typically include a drive unit, specifically an electric motor. The electric motor is powered by at least one battery cell, and usually via an entire battery pack containing multiple battery cells. In this case, the battery pack includes a housing in which one or more battery cells are arranged. Multiple battery cells are typically combined to form a battery module and interconnected within the battery module.

[0003] Battery packs typically also include a battery management system (BMS). The BMS's functions include monitoring the voltage, current, and temperature of the battery cells, controlling the load and charging of the battery cells, and achieving cell balancing. Furthermore, the BMS is usually connected to a connector through which the battery pack can be charged or discharged.

[0004] The drive unit needs to be supplied with the largest possible current and power by the battery module. The limiting factor for high current flow and high power output is that the BMS components must not be heated above their specified temperature. Conventional BMS components are typically designed for temperatures up to 85°C. Summary of the Invention

[0005] Therefore, the core objective of this invention is to provide an electric bicycle battery system, an electric bicycle having such a battery system, and a method for controlling the electric bicycle battery system, through which high voltage and high power transmission to and from the battery cell can be achieved, and the system and method are also applicable to higher temperatures.

[0006] The present invention achieves the above-mentioned objectives through the features of the independent claims. Other practical embodiments and advantages are described in the dependent claims.

[0007] The electric bicycle battery system of the present invention includes at least one battery cell connected to a connector via a power line.

[0008] Specifically, the electric bicycle battery system includes multiple battery cells assembled to form a battery pack. The individual battery cells are electrically connected. The electric bicycle battery system particularly includes multiple battery cells, specifically 20 to 35 individual 3.6V battery cells, preferably 24 or 33 individual 3.6V battery cells. The battery cells are specifically configured in 11 series 3 parallel (11s3p), 12 series 2 parallel (12s2p), or 13 series 1 parallel (13s1p) connection configurations. In the 11 series 3 parallel (11s3p) configuration, 11 battery cells are connected in series as a group, for a total of 3 groups in parallel. In the 12 series 2 parallel (12s2p) configuration, 12 battery cells are connected in series as a group, for a total of 2 groups in parallel. The battery cells in the 12 series 2 parallel (12s2p) configuration are particularly arranged in a two-layer configuration, with each layer having two rows of battery cells, and each row having 4 battery cells. The battery cells are particularly cylindrical in design. Generally, the battery cells preferably provide a supply voltage in a low voltage range. The rated voltage of the battery module is particularly low, below 60V, preferably between 35V and 45V, and more preferably 39.6V or 43V.

[0009] Power supplied by the battery cell is transmitted to at least one connector via the power line (discharge mode), or charging power is transmitted from the connector to the at least one battery cell in order to charge the battery cell (charging mode).

[0010] (A) Battery cells can be charged or discharged via connectors of the electric bicycle battery system. In other words, energy can be supplied to at least one battery cell via a connector (e.g., from a charging plug). Through this connector, at least one battery cell can be connected to a load (here, an electric motor providing auxiliary power) and supplied with energy. Overall, the connector forms the interface between the battery cells and the entire electric bicycle battery system and the charging system or electric motor control electronics.

[0011] A switch is arranged in the power line, configured to selectively establish a connection between a connector and at least one battery cell. The switch specifically includes two sets of metal-oxide-semiconductor field-effect transistors (MOSFETs) that connect at least one battery cell to the connector in a manner known in the art, allowing the battery cell to be charged or discharged (charge or discharge mode), or disconnecting the connection between the connector and the battery cell (safe state), or implementing a pre-discharge mode or a pre-charge mode. In the pre-discharge or pre-charge mode, the battery cell is discharged or charged in a way that limits the current or energy by using a MOSFET with current-limiting circuitry or a MOSFET with PWM control.

[0012] Furthermore, the electric bicycle battery system includes sensor units for detecting the state values ​​of the battery cells. Such sensor units are, in particular, battery monitoring integrated chips (BMICs). A BMIC is a specially configured integrated circuit used to continuously monitor and control the performance parameters and state of the battery cells within the battery pack (especially groups of battery cells connected in parallel). In this case, the BMIC detects the state values ​​of the battery cells, such as voltage, temperature, and state of charge, to ensure the safe and efficient operation of the battery cells. The BMIC may also have battery cell equalization, overvoltage and undervoltage protection, overcurrent protection, and temperature management functions to extend the lifespan of the battery cells and minimize the risk of failure or damage. BMICs are, in particular, standard components.

[0013] Additionally, the electric bicycle battery management system includes a controller connected to the sensor unit and configured to receive and evaluate state values ​​detected by the sensor unit. Evaluating state values ​​specifically means that the controller is configured to compare the received state values ​​with defined limit values ​​and detect whether they are exceeded or fallen below the corresponding limit values. This controller is particularly a microcontroller. The controller preferably includes memory, especially NOR flash memory, specifically for storing the detected state values.

[0014] According to the present invention, the controller is connected to the switch and configured to send a control signal to the switch for controlling the switching on and off. That is, based on the control signal, the switch is driven to a state that enables the charging or discharging of the battery cell, or to a safe state in which the battery cell is placed and the connector is electrically isolated from the battery cell.

[0015] The combination of sensor units and controllers can also be called a battery management system, which connects at least one battery unit to other components of the electric bicycle system in a controlled and safe manner.

[0016] In the architecture of the electric bicycle battery system proposed in this invention, the sensor unit is a purely detection and measurement unit, while the controller is a logic unit or control unit that controls the switching on and off as needed. The controller is configured to collect all necessary information from the sensor unit or other units to make safety-related decisions and send necessary control signals to the switch. Due to the purely detection function of the sensor unit, standard components suitable for temperatures up to 125°C can be used in this case.

[0017] Overall, the electric bicycle battery system is a compact unit, in which all electronic components, except for the battery unit, are arranged on a printed circuit board.

[0018] Overall, by separating the sensor unit from the controller that provides control via a switch, components with higher temperature specifications can be used, thus enabling power levels of up to 1200W peak power or 950W continuous power to be transmitted on the power line.

[0019] Specifically, the controller is connected to a high-side switch used to control the on / off state of the switch. The controller is configured to send one or more control signals to the high-side switch, which provides the voltage required to actuate the switch (specifically, the two sets of MOSFETs). Therefore, the high-side switch can also be referred to as an actuator. The high-side switch is an electronic circuit component that controls the flow of current from the positive power supply terminal (high side) of the battery cell to the connector. In particular, the high-side switch provides electrical isolation between the controller and the switch.

[0020] In another practical embodiment of the electric bicycle battery system, the controller is also connected to at least one additional sensor. The advantage of the circuit architecture in this invention, where the controller is connected to a switch rather than the BMIC, is that the controller can process additional sensor signals in addition to those from the sensor unit, thereby providing more information to improve the performance of the electric bicycle battery system and enhance the safety of the electric bicycle battery device.

[0021] Specifically, the controller is connected to at least one humidity sensor. In this case, the humidity sensor may be a sensor that measures the humidity in an area of ​​the battery cell (e.g., inside the housing of the battery module), and / or the humidity sensor may detect humidity in an area of ​​the sensor unit or the electronic components of the controller. For example, if excessive humidity is detected in an area of ​​the battery cell or the electronic components of the controller, the connection between the connector and the battery cell can be disconnected (safety condition).

[0022] As an alternative or supplement, the controller can be connected to another sensor in the form of a voltmeter. This voltmeter is specifically configured to detect the voltage drop across the switch. The controller can then compare the detected voltage with a desired voltage derived from control commands sent to the switch, and, if appropriate, detect a fault or defect in the switch, thereby triggering a safety state accordingly.

[0023] Specifically, the controller is connected to and configured to control and monitor a fuse in the power line. When an excessive current occurs in the power line, the controller can activate or trigger the fuse, thereby disconnecting the connector from at least one battery cell for at least a defined time interval. To do this, the controller monitors the defined current-time characteristics in the power line and activates or triggers the fuse when these characteristics are exceeded (i.e., when an excessive current flows within a given time interval). This fuse is, in particular, a non-resettable fuse.

[0024] As an alternative or supplement, a second fuse, particularly a short-circuit fuse (e.g., a tubular fuse), can be installed in the power line to disconnect the connection between the connector and at least one battery cell independently of the controller. When the predefined current-voltage characteristics of the electric bicycle are exceeded, the short-circuit fuse disconnects the connection in the power line in a manner known per se. When this fuse is triggered, the connection between the connector and the battery cell is permanently broken, and the electric bicycle battery system can only be restored to function after the fuse is replaced.

[0025] In another practical embodiment, the controller is connected to the connector via a communication bus. Therefore, diagnostic information from the MCU can be transmitted through the connector, and conversely, software updates or bug fixes can be loaded onto the MCU via the connector. This communication bus is, in particular, a CAN bus.

[0026] The controller can also be connected to a human-machine interface (HMI). In this case, the HMI can be a display or one or more optical elements (especially LEDs) and / or a speaker for sound generation. In this way, the controller can communicate the status of the electric bicycle's battery system and / or battery cells to the user via the HMI.

[0027] In addition, the HMI may include an actuation device (such as a button) that can, in particular, put the electric bicycle battery system into a deactivated or activated mode. Specifically, the controller is functionally connected to this actuation device.

[0028] In another practical embodiment of an electric bicycle battery system, a shunt resistor is arranged in the power line. In a battery management system, the shunt resistor is a precision low-ohm resistor connected in series in the current path of the battery cell to measure the current flowing through the cell. By generating a small but measurable voltage proportional to the current, the shunt resistor can accurately monitor the charge and discharge current. The voltage drop across the shunt resistor can be measured by a sensor unit, and the measured value is provided to the controller by the sensor unit.

[0029] Specifically, the shunt resistor is functionally connected to the safety current limiter. The safety current limiter circuitry acts as another sensor, providing the controller with the battery cell's output current as a redundant information source. The safety current limiter is connected to the controller and reports the presence of overcurrent or short circuits, allowing the controller to generate control signals. For this purpose, the safety current limiter can be configured to send control signals directly to the switch or high-side switch to achieve a faster response time.

[0030] The present invention also relates to an electric bicycle having the above-described electric bicycle battery system. For this purpose, the electric bicycle includes an electric bicycle battery system and a drive unit connected to the electric bicycle battery system and the battery cells therein.

[0031] The present invention also relates to a method for controlling an electric bicycle battery system (particularly the aforementioned electric bicycle battery system) having at least one battery cell, wherein a state value of at least one battery cell is transmitted from a sensor unit to a controller. The controller establishes or disconnects a connection between a connector and at least one battery cell based on this state value. Selective connection establishment is achieved, in particular, by a switch arranged in the power line, to which the controller can send a control signal. The controller is particularly responsible for the actuation and safety of the electric bicycle battery system. Attached Figure Description

[0032] Other practical embodiments and advantages will be described below in conjunction with the accompanying drawings. In the drawings:

[0033] Figure 1 A block diagram showing the battery system of an electric bicycle; and

[0034] Figure 2 Showing according to Figure 1 A more detailed block diagram of the electric bicycle battery system. Detailed Implementation

[0035] Figure 1 A schematic block diagram of an electric bicycle battery system 10 is shown. The electric bicycle battery system 10 includes a plurality of battery cells 12, which are connected to a connector 16 via power lines 14.

[0036] A switch 18 is arranged in the power line 14, which connects the connector 16 and the battery unit 12 to each other according to the switch position.

[0037] The electric bicycle battery system 10 also includes a sensor unit 20 connected to the battery cell 12. The sensor unit 20 is a battery control unit (BMIC) for detecting the state values ​​of the battery cell 12. Specifically, the sensor unit 20 detects the state of charge and temperature of the battery cell 12.

[0038] Furthermore, sensor unit 20 is connected to controller 22. Controller 22 is configured to receive and evaluate the state data of battery cell 12 detected by sensor unit 20. Controller 22 is also connected to connector 16 and can also receive signals from connector 16 and transmit signals thereto.

[0039] The controller 22 is further connected to the switch 18 and is configured to operate the switch 18 via a control signal. Based on the status value and / or the signal originating from the connector 16, the controller 22 can output a control signal and provide it to the switch 18.

[0040] In summary, the controller 22 constitutes the safety and logic unit of the electric bicycle battery system, while the sensor unit 20 is implemented as a pure sensing unit.

[0041] Figure 2 Showing according to Figure 1 A detailed view of the circuit diagram.

[0042] Such as combination Figure 1 As described, the electric bicycle battery system 10 includes multiple battery cells 12, connectors 16, power lines 14, sensor units 20, controllers 22, and switches 18.

[0043] In this case, switch 18 consists of two sets of MOSFETs 24. Depending on the switch state, these MOSFETs can be placed in a state in which the battery cell 12 is charged and discharged via the power line 14, or in a state in which the battery cell 12 is isolated from the connector 16 (safe state).

[0044] The controller 22 is connected to the switch 18 via the high-side switch 26. For this purpose, the controller 22 sends a control signal 23 to the high-side switch 26, which is configured to control the MOSFET 24 to either be in the off or on state.

[0045] In addition, the controller 22 is also connected to a humidity sensor 28, which detects the humidity in the area of ​​the electronic components of the electric bicycle battery system 10.

[0046] The controller 22 is connected to the connector 16 via a communication bus. The connection between the connector 16 and the controller 22 can be achieved wirelessly via a corresponding transceiver 30.

[0047] Additionally, the controller 22 is connected to the HMI 32 (human-machine interface). The HMI 32 can display, for example, the status of the battery cell 12 (such as state of charge) and / or whether the electric bicycle battery system 10 is in a safe or active state.

[0048] HMI 32 may include an actuation element (not shown), the controller 22 may read the activation state of the actuation element through detection circuit 34, and based on this, for example, disconnect or establish the connection between battery cell 12 and connector 16.

[0049] Controller 22 can also be connected to memory 36.

[0050] To detect the voltage drop across switch 18, controller 22 is connected to voltmeter 38. Controller 22 can then compare the voltage drop determined by voltmeter 38 with a target voltage drop set based on control signal 23.

[0051] As a safety element, the electric bicycle battery system 10 has a fuse 40 in the power line 14. The controller 22 is functionally connected to the fuse 40 (connection not shown) and can activate the fuse 40 when a limit value is exceeded, thereby disconnecting the connection between the connector 16 and the battery cell 12.

[0052] Another safety element is another fuse 42 in the power line 14, which in this case can be activated independently of the controller 22. Fuse 42 is in particular a short-circuit fuse, such as a tubular fuse.

[0053] A shunt resistor 44 is connected in series with the battery cell 12, and this shunt resistor is also used to monitor the battery cell 12. The shunt resistor 44 is monitored by the sensor unit 20, and the measured value is transmitted to the controller 22.

[0054] Shunt resistor 44 is also connected to safety current limiter 46. The circuitry of safety current limiter 46 acts as a secondary sensor, providing the output current of battery cell 12 to controller 22 as a redundant information source. Safety current limiter 46 is configured to notify controller 22 in the event of a safety-related event (e.g., overcurrent or short circuit) so that controller 22 can respond with a corresponding control signal. In this case, safety current limiter 46 is also configured to send a control signal directly to high-side switch 26 for a faster response time.

[0055] In addition, the electric bicycle battery system 10 includes a power management unit 48 for providing various power supply voltages to the various components present in the electric bicycle battery system 10. This power management unit 48 is, in particular, a power management interface (PMIC).

[0056] List of reference numerals

[0057] 10 Electric bicycle battery system

[0058] 12 battery cells

[0059] 14 Power lines

[0060] 16 connectors

[0061] 18 switches

[0062] 20 sensor units

[0063] 22 Controllers

[0064] 23 Control Signals

[0065] 24 MOSFET

[0066] 26 High-side switch

[0067] 28 Humidity Sensor

[0068] 30 Communication bus / transceiver

[0069] 32 HMI

[0070] 34 Detection Circuit

[0071] 36. Memory

[0072] 38 Voltmeter

[0073] 40 Fuse

[0074] 42 Fuse

[0075] 44 Shunt Resistor

[0076] 46 Safety Current Limiter

[0077] 48 Power Management Unit

Claims

1. An electric bicycle battery system (10), comprising: - At least one battery cell (12) and a connector (16), wherein the connector (16) is interconnected with the at least one battery cell (12) via a power line (14); - Sensor unit (20), the sensor unit (20) is used to detect the state value of the at least one battery cell (12); - A controller (22), which is connected to the sensor unit (20) and configured to receive and evaluate the state value of the sensor unit (20); - A switch (18) is arranged in the power line (14) for selectively establishing a connection between the connector (16) and the at least one battery cell (12); The controller (22) is connected to the switch (18) and configured to send a control signal (23) to the switch (18) for controlling the on / off state of the switch (18).

2. The electric bicycle battery system (10) as claimed in the preceding claims, characterized in that, The controller (22) is connected to a high-side switch (26), wherein the high-side switch (26) is configured to receive the control signal (23) from the controller (22) and actuate the switch (18) based on the control signal (23).

3. The electric bicycle battery system (10) as described in any of the preceding claims, characterized in that, The controller (22) is connected to at least one additional sensor (28, 38).

4. The electric bicycle battery system (10) as claimed in the preceding claims, characterized in that, The controller (22) is connected to at least one humidity sensor (28).

5. The electric bicycle battery system (10) as described in claims 3 and 4, characterized in that, The controller (22) is connected to a sensor in the form of a voltmeter (38), wherein the voltmeter (38) is configured to measure the voltage drop across the switch (18).

6. The electric bicycle battery system (10) as described in any of the preceding claims, characterized in that, The controller (22) is connected to the fuse (40) in the power line (14) and is configured to control and monitor the fuse (40).

7. The electric bicycle battery system (10) as claimed in any of the preceding claims, characterized in that, A fuse (42) is arranged in the power line (14), and the fuse (42) can be triggered independently of the controller (22).

8. The electric bicycle battery system (10) as described in any of the preceding claims, characterized in that, The controller (22) is connected to the connector (16) via a communication bus (30), and / or the controller (22) is connected to the human-machine interface (HMI) (32).

9. An electric bicycle comprising an electric bicycle battery system (10) as claimed in any one of claims 1 to 8.

10. A method for controlling an electric bicycle battery system (10) having at least one battery cell (12), wherein a state value of the at least one battery cell (12) is transmitted from a sensor unit (20) to a controller (22), and wherein the controller (22) establishes or disconnects a connection between a connector (16) and the at least one battery cell (12) based on the state value.

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