Battery protection board based on unmanned aerial vehicle

Abstract

The invention discloses a battery protection board based on an unmanned aerial vehicle. A battery module in the battery protection board comprises a plurality of battery cells which are connected in series. The voltameter assembly comprises a first voltage detection circuit and a temperature detection circuit, and the first voltage detection circuit is electrically connected with the battery module and used for collecting voltage information of each battery cell. The temperature detection circuit is arranged on the battery module and used for detecting temperature information of the battery module. The voltameter assembly is connected with the flight controller and used for obtaining voltage information and temperature information of the battery module according to the first voltage detection circuit and the temperature detection circuit, obtaining battery information of the battery module, determining the battery health state of the battery module according to the voltage information, the temperature information and the battery information, and sending the battery health state to the flight controller. The battery state of health is sent to a flight controller. Therefore, the flight controller can provide more accurate battery state perception and decision support for the unmanned aerial vehicle according to the battery health state.

Description

Technical Field

[0001] This invention relates to the field of drone technology, and more particularly to a battery protection board for drones. Background Technology

[0002] With the rapid development of drone technology, its application areas continue to expand. Currently, mainstream drone battery protection boards mainly rely on a basic battery management system (BMS), which monitors the voltage of individual batteries in real time through voltage sensors. However, this data acquisition method is relatively simple, and in actual control, it is prone to inaccurate predictions, resulting in a poor user experience. Summary of the Invention

[0003] This invention provides a battery protection board for drones. A fuel gauge component determines the battery health status of the battery module based on voltage, temperature, and battery information, and sends this status to the flight controller. In this way, the flight controller can provide the drone with more accurate battery status perception and decision support based on the battery health status.

[0004] In a first aspect, the present invention provides a battery protection board based on a drone, the battery protection board including a fuel gauge assembly and a battery module; The battery module includes multiple battery cells connected in series; The fuel gauge assembly includes a first voltage detection circuit and a temperature detection circuit. The first voltage detection circuit is electrically connected to the battery module and is used to collect the voltage information of each battery cell in the battery module. The temperature detection circuit is disposed on the battery module and is used to detect the temperature information of the battery module. The fuel gauge assembly is connected to the flight controller and is used to obtain the voltage information and temperature information of the battery module according to the first voltage detection circuit and the temperature detection circuit, respectively, as well as the battery information of the battery module. Based on the voltage information, the temperature information and the battery information, the assembly determines the battery health status of the battery module and sends the battery health status to the flight controller.

[0005] Optionally, determining the battery health status of the battery module based on the voltage information, the temperature information, and the battery information includes: extracting the voltage fluctuation rate of the battery module based on the voltage information, extracting the temperature rise slope of the battery module based on the temperature information, and extracting the historical cycle count of the battery module based on the battery information. Determine the full discharge capacity of the battery module, and calculate the capacity decay coefficient of the battery module based on the historical cycle count and the full discharge capacity. Determine the current information of the battery module, and determine the internal resistance growth coefficient of the battery module based on the temperature rise slope and the current information; The voltage consistency deviation coefficient of the battery module is determined based on the voltage fluctuation rate. A first weight for the capacity decay coefficient, a second weight for the internal resistance growth coefficient, and a third weight for the voltage consistency deviation coefficient are determined, and the battery health status of the battery module is determined based on the capacity decay coefficient, the first weight, the internal resistance growth coefficient, the second weight, the voltage consistency deviation coefficient, and the third weight.

[0006] Optionally, the battery health state is SOH, the capacity decay coefficient is α, the internal resistance growth coefficient is β, the voltage consistency deviation coefficient is γ, the first weight is ω1, the second weight is ω2, and the third weight is ω3; The formula for calculating the battery health status of the battery module is: SOH = ω1×α + ω2×β + ω3×γ.

[0007] Optionally, the battery protection board may also include a main control component, an over-discharge control circuit, and an overcharge control circuit; The main control component is connected to the fuel gauge component, the overcharge control circuit, and the over-discharge control circuit, respectively, and is used to obtain the battery health status of the battery module. When the battery health status is determined to be less than a first preset value, the main control component adjusts the maximum value of the charging voltage of the overcharge control circuit or adjusts the maximum value of the discharging voltage of the over-discharge control circuit.

[0008] Optionally, the battery protection board may further include a main control component and a first discharge circuit; The main control component includes a second voltage detection circuit; The second voltage detection circuit is used to detect the voltage information of each battery cell in the battery module; The main control component is connected to the first discharge circuit and is used to discharge the battery cell with larger voltage information when the difference between the voltage information of two battery cells is detected to be greater than a second preset value, so as to reduce the difference between the voltage information of the two battery cells.

[0009] Optionally, the battery module includes a first battery cell and a second battery cell; The first discharge circuit includes a first NPN transistor, a first PNP transistor, a second NPN transistor, and a second PNP transistor; The control electrode of the first NPN transistor is electrically connected to the first control terminal of the main control component, the first electrode of the first NPN transistor is electrically connected to the first ground terminal, the second electrode of the first NPN transistor is electrically connected to the control electrode of the first PNP transistor, the first electrode of the first PNP transistor is electrically connected to the positive electrode of the battery module, and the second electrode of the first PNP transistor is electrically connected to the negative electrode of the first battery module. The control electrode of the second NPN transistor is electrically connected to the second control terminal of the main control component. The first electrode of the second NPN transistor is electrically connected to the first ground terminal. The second electrode of the second NPN transistor is electrically connected to the control electrode of the second PNP transistor. The first electrode of the second PNP transistor is electrically connected to the negative electrode of the first battery cell. The second electrode of the second PNP transistor is electrically connected to the first ground terminal.

[0010] Optionally, the main control component is used to control the second control terminal to send a conduction signal to turn on the second NPN transistor when it detects that the voltage information of the first battery cell is greater than the voltage information of the second battery cell, and the difference between the two is a second preset value, so as to discharge the first battery cell, and at the same time control the first PNP transistor to turn on to form a closed-loop discharge path.

[0011] Optionally, the main control component is also used to acquire the battery health status and temperature information of the battery module, and calculate the AC internal resistance of the battery cell based on the battery health status and temperature information. The internal resistance voltage drop compensation amount of the battery cell is calculated based on the AC internal resistance, and the second preset value is compensated based on the internal resistance voltage drop compensation amount.

[0012] Optionally, the battery protection board may further include a main control component and a second discharge circuit; The main control component is also used to obtain the battery health status of the battery module after a preset time, and when the battery health information is greater than a third preset value, control the second discharge circuit to reduce the voltage of the battery module to a safe threshold.

[0013] Optionally, the second discharge circuit includes a third NPN transistor and a third PNP transistor; The control electrode of the third NPN transistor is electrically connected to the main control component, the first electrode of the third NPN transistor is electrically connected to the first ground terminal, the second electrode of the third NPN transistor is electrically connected to the control electrode of the third PNP transistor, the first electrode of the third PNP transistor is electrically connected to the positive terminal of the battery module, and the second electrode of the third PNP transistor is electrically connected to the first ground terminal.

[0014] In this embodiment of the invention, the battery protection board includes a battery module comprising multiple battery cells connected in series. The fuel gauge assembly includes a first voltage detection circuit and a temperature detection circuit. The first voltage detection circuit is electrically connected to the battery module and is used to collect voltage information from each battery cell. The temperature detection circuit is located on the battery module and is used to detect the temperature information of the battery module. The fuel gauge assembly is connected to the flight controller and is used to acquire the voltage and temperature information of the battery module, as well as the battery information, based on the first voltage detection circuit and the temperature detection circuit. Based on the voltage, temperature, and battery information, the assembly determines the battery health status of the battery module and sends the battery health status to the flight controller. Thus, the flight controller can provide the drone with more accurate battery status perception and decision support based on the battery health status. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of a battery protection board based on a drone provided in an embodiment of the present invention; Figure 2 This is a circuit diagram of the main control component provided in an embodiment of the present invention; Figure 3 This is a circuit diagram of an over-discharge control circuit and an overcharge control circuit provided in an embodiment of the present invention; Figure 4 This is a circuit diagram of the first discharge circuit provided in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be fully described below with reference to the accompanying drawings of the embodiments of this invention through specific implementation methods. Obviously, the described embodiments are only some, not all, embodiments of this invention. Various modifications and variations can be made to this invention without departing from the spirit or scope of this invention, which will be obvious to those skilled in the art. Therefore, this invention is intended to cover modifications and variations of this invention that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents.

[0017] Furthermore, the terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as "an," "one," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. In addition, descriptions of "same" or "equal" in the embodiments of this disclosure do not mean that two objects are completely equal in size or shape; they are allowed to be approximately the same or approximately equal within a certain error range.

[0018] Figure 1 This is a circuit diagram of a battery protection board for a drone provided in an embodiment of the present invention. See also... Figure 1 The battery protection board includes a fuel gauge assembly 10 and a battery module 20. The battery module 20 includes multiple battery cells connected in series. The fuel gauge assembly 10 includes a first voltage detection circuit 110 and a temperature detection circuit 120. The first voltage detection circuit 110 is electrically connected to the battery module 20 and is used to collect voltage information of each battery cell in the battery module 20. The temperature detection circuit 120 is disposed on the battery module 20 and is used to detect the temperature information of the battery module 20. The fuel gauge assembly 10 is communicatively connected to the flight controller 011 and is used to acquire the voltage and temperature information of the battery module 20 according to the first voltage detection circuit 110 and the temperature detection circuit 120, as well as the battery information of the battery module 20. Based on the voltage, temperature, and battery information, it determines the battery health status of the battery module 20 and sends the battery health status to the flight controller 01.

[0019] Specifically, such as Figure 1As shown, the battery module 20 includes multiple battery cells connected in series. For example, the battery module 20 includes two battery cells, designated as the first battery cell and the second battery cell. The negative terminal BAT1-1 of the first battery cell is electrically connected to the positive terminal BAT2+1 of the second battery cell. The positive terminal BAT1+1 of the first battery cell is connected to the positive terminal PACK+ of the battery module 20, and the negative terminal BAT2-1 of the second battery cell is connected to the second ground terminal. The fuel gauge assembly 10 includes a first voltage detection circuit 110 and a temperature detection circuit 120. The first voltage detection circuit 110 can be electrically connected to the positive terminal PACK+ of the battery module 20, thereby measuring the voltage information of each battery cell in the battery module 20. The temperature detection circuit 120 may include a plug-in NTC temperature sensor, which can cover the central area, edge area, and tab area of ​​the battery module 20, thereby acquiring multi-dimensional temperature data of the battery module 20 and obtaining the temperature information of the battery module 20. The power meter assembly 10 is equipped with control logic, which can filter and reduce noise on the voltage information of each battery cell detected by the first voltage detection circuit 110 and the temperature information detected by the temperature detection circuit 120, and eliminate environmental interference signals.

[0020] On the other hand, the fuel gauge component 10 can also calculate the battery health status of the battery module 20 based on the collected voltage and temperature information. Specifically, the fuel gauge component 10 can also acquire battery information of the battery module 20. This battery information may include parameters such as the historical cycle count and full discharge capacity of the battery module 20, which are parameters recorded in the battery module 20 and do not require measurement. Therefore, the fuel gauge component 10 can calculate the battery health status of the battery module 20 based on the acquired voltage, temperature, and battery information. Battery health status is a core indicator used to assess the degree of performance degradation of the battery module 20 relative to its brand-new state. For example, it can represent the degradation of the remaining usable capacity of the battery module 20 (a brand-new battery has a nominal capacity of 100Ah; if the current SOH is 80%, its actual maximum usable capacity is approximately 80Ah). Alternatively, it could be due to internal aging and performance degradation (increased internal resistance: electrode aging, electrolyte decomposition, etc., lead to increased internal resistance, reducing output power, causing more severe heat generation during charging and discharging, and more drastic changes in terminal voltage); or it could be a prediction of remaining lifespan. Typically, when the battery health drops to 70%-80% of its rated value, the battery module is considered to have reached the end of its lifespan (specific standards vary depending on the application). Battery health status can reflect various issues with the battery module 20. The fuel gauge assembly 10 and the flight controller 01 can be connected via I2C communication. Therefore, in this embodiment, the battery health status calculated by the fuel gauge assembly 10 is transmitted to the flight controller 01, enabling the flight controller 01 to combine the battery health status of the battery module 20 with appropriate decision support for the drone, effectively improving data reliability.

[0021] In summary, the battery module in the battery protection board of this embodiment includes multiple battery cells connected in series. The fuel gauge assembly includes a first voltage detection circuit and a temperature detection circuit. The first voltage detection circuit is electrically connected to the battery module and is used to collect the voltage information of each battery cell. The temperature detection circuit is disposed on the battery module and is used to detect the temperature information of the battery module. The fuel gauge assembly is connected to the flight controller and is used to obtain the voltage and temperature information of the battery module, as well as the battery information of the battery module, based on the first voltage detection circuit and the temperature detection circuit, respectively. Based on the voltage information, temperature information, and battery information, the assembly determines the battery health status of the battery module and sends the battery health status to the flight controller. In this way, the flight controller can provide the UAV with more accurate battery status perception and decision support based on the battery health status.

[0022] Optionally, based on the above embodiments, see also... Figure 1In one embodiment, determining the battery health status of the battery module 20 based on voltage information, temperature information, and battery information includes: extracting the voltage fluctuation rate of the battery module based on the voltage information, where the voltage fluctuation rate characterizes the voltage fluctuation changes of each battery cell in the battery module 20; then extracting the temperature rise slope of the battery module based on the temperature information, where the temperature rise slope characterizes the rate of temperature change of the battery module 20 during operation; and extracting the historical cycle count and full discharge capacity of the battery module 20 based on the battery information. The capacity decay coefficient of the battery module 20 is calculated based on the historical cycle count and full discharge capacity, where the capacity decay coefficient characterizes the capacity decay of the battery module 20, and its value is in the range [0, 1], where 1 indicates no capacity decay and 0 indicates complete failure. Furthermore, the current information of the battery module 20 can be determined through the current detection unit. Based on the temperature rise slope and current information, the internal resistance growth coefficient of the battery module 20 can be determined. The internal resistance growth coefficient characterizes the increase in internal resistance of the battery module 20, taking values ​​in the range [0, 1], where 1 indicates no increase in internal resistance and 0 indicates a very large increase in internal resistance. The voltage consistency deviation coefficient of the battery module 20 can then be determined based on the voltage fluctuation rate. This coefficient characterizes the voltage difference among the individual battery cells in the battery module 20, taking values ​​in the range [0, 1], where 1 indicates that the voltage of each battery cell is completely consistent and 0 indicates extremely poor voltage consistency. The entropy weight method can then be used to determine the weights of each coefficient, such as... The first weight of the capacity decay coefficient, the second weight of the internal resistance growth coefficient, and the third weight of the voltage consistency deviation coefficient are determined. Based on these factors, the battery health status of battery module 20 is determined. This ensures that the parameters used to calculate the battery health status include internal resistance, capacity, and voltage, which is beneficial for subsequent decision-making based on the battery health status.

[0023] It should be noted that, in one embodiment, the battery health state is SOH, the capacity decay coefficient is α, the internal resistance growth coefficient is β, the voltage consistency deviation coefficient is γ, the first weight is ω1, the second weight is ω2, and the third weight is ω3. The formula for calculating the battery health state of the battery module is: SOH = ω1 × α + ω2 × β + ω3 × γ. Wherein, ω1 + ω2 + ω3 = 1, meaning that this embodiment of the invention does not limit the specific values ​​of the first, second, and third weights, and those skilled in the art can dynamically adjust them according to actual operating conditions.

[0024] Optionally, based on the above embodiments, Figure 2 This is a circuit diagram of the main control component provided in an embodiment of the present invention. Figure 3 This is a circuit diagram of an over-discharge control circuit and an overcharge control circuit provided in an embodiment of the present invention. Figure 2 and Figure 3 The battery protection board also includes a main control component 30, an over-discharge control circuit 310, and an overcharge control circuit 320. The main control component 30 is connected to the fuel gauge component 10, the overcharge control circuit 310, and the over-discharge control circuit 320, respectively, and is used to obtain the battery health status of the battery module 20. When the battery health status is determined to be less than a first preset value, the main control component adjusts the maximum value of the charging voltage of the overcharge control circuit or adjusts the maximum value of the discharging voltage of the over-discharge control circuit.

[0025] Specifically, such as Figure 2 and Figure 3 As shown, after calculating the battery health status of the battery module 20 through the fuel gauge component 10, the battery health status is transmitted to the main control component 10. The main control component 10 has a built-in neural network algorithm that can dynamically adjust the maximum rechargeable voltage of the current battery module 20 based on the battery health status. Figure 3 As shown, the over-discharge control circuit 310 and the overcharge control circuit 320 can share a single control chip. The DO port of the over-discharge control circuit 310 is electrically connected to this control chip, and the CO port of the overcharge control circuit 320 is also electrically connected to the control chip. Furthermore, the control chip is electrically connected to the positive terminal PACK+ of the battery module 20, the positive terminal BAT1+1 and negative terminal BAT1-1 of the first battery cell, the positive terminal BAT2+1 of the second battery cell, the negative terminal BAT2-1 of the second battery cell, and the negative terminal PACK- of the battery module 20, thereby providing overcharge and over-discharge protection for the battery module 20. For example, in one embodiment, when the main control component 30 detects that the battery health status of the battery module 20 is less than a second preset value (e.g., 80%), it adaptively adjusts the overcharge protection threshold of the overcharge control circuit 320 from 4.25V to 4.18V, thereby adjusting the maximum rechargeable voltage of the battery module 20 and preventing over-stress damage to aging battery cells. Similarly, the same method can be used to control the over-discharge protection threshold of the over-discharge control circuit 310, thereby adjusting the maximum discharge voltage of the battery module 20, effectively delaying the degradation of the battery module 20, and it is expected to extend the battery module's lifespan by more than 20%.

[0026] It should be noted that, as Figure 3 As shown, the battery protection board may also include a MOSFET switch array 330, which is electrically connected to the port DO of the over-discharge control circuit 310 and the port CO of the overcharge control circuit 320, thereby providing support for overcharge protection and over-discharge protection.

[0027] Optionally, based on the above embodiments, Figure 4 This is a circuit diagram of the first discharge circuit provided in an embodiment of the present invention. See also... Figure 2 and Figure 4 The battery protection board also includes a main control component 30 and a first discharge circuit 40. The main control component 30 includes a second voltage detection circuit 340. The second voltage detection circuit 340 is used to detect the voltage information of each battery cell in the battery module 20. The main control component 30 is connected to the first discharge circuit 40 and is used to discharge the battery cell with the larger voltage information when it detects that the difference between the voltage information of two battery cells is greater than a second preset value, so as to reduce the difference between the voltage information of the two battery cells.

[0028] Specifically, such as Figure 2 and Figure 4 As shown, the main control component 30 includes a second voltage detection circuit 340. The second voltage detection circuit 340 is used to detect the voltage information of each battery cell in the battery module 20. After detecting the voltage information of each battery cell, the main control component 30 compares the voltage information of any two battery cells in real time. When it detects that the difference between the voltage information of two battery cells is greater than a second preset value, it discharges the battery cell with the larger voltage information, thereby improving the voltage consistency of each battery cell in the battery module 20.

[0029] For example, such as Figure 4 As shown, the battery module 20 includes a first battery cell and a second battery cell. The first discharge circuit 50 includes a first NPN transistor Q1, a first PNP transistor Q2, a second NPN transistor Q3, and a second PNP transistor Q4. The control terminal of the first NPN transistor Q1 is electrically connected to the first control terminal BAL1 of the main control component, the first terminal of the first NPN transistor Q1 is electrically connected to the first ground terminal, the second terminal of the first NPN transistor Q1 is electrically connected to the control terminal of the first PNP transistor Q2, the first terminal of the first PNP transistor Q2 is electrically connected to the positive terminal PACK+ of the battery module, and the second terminal of the first PNP transistor Q2 is electrically connected to the negative terminal BAT1-1 of the first battery cell. The control electrode of the second NPN transistor Q3 is electrically connected to the second control terminal BAL2 of the main control component 30. The first electrode of the second NPN transistor Q3 is electrically connected to the first ground terminal. The second electrode of the second NPN transistor Q3 is electrically connected to the control electrode of the second PNP transistor Q4. The first electrode of the second PNP transistor Q4 is electrically connected to the negative electrode BAT1-1 of the first battery cell. The second electrode of the second PNP transistor Q4 is electrically connected to the first ground terminal.

[0030] Specifically, Figure 4In the illustrated embodiment, the example given is that the voltage information of the first battery cell is greater than that of the second battery cell. That is, the difference between the voltage information of the first battery cell and the voltage information of the second battery cell is greater than a second preset value. At this time, the potential of the negative terminal BAT1-1 of the first battery cell (that is, the positive terminal BAT2+1 of the second battery cell) is higher. Then, the main control component 30 controls the second control terminal BAL2 to send a conduction signal to the second NPN transistor Q3 (that is, the NPN transistor corresponding to the first battery cell with the larger voltage information), so that the second NPN transistor Q3 conducts. Through the current limiting resistor, the electrical energy is released to the load terminal to discharge the first battery cell. At the same time, the main control component 30 controls the first PNP transistor Q2 to conduct, providing a path for the entire discharge current and forming a closed-loop discharge path to avoid reverse current impact and protect the discharge of the first battery cell. In this way, by building an active balancing circuit through the NPN-PNP complementary symmetry transistor structure, the energy loss in the energy balancing process is reduced.

[0031] It should be noted that, based on the above embodiments, the main control component 30 is also used to acquire the battery health status and temperature information of the battery module 20, and calculate the AC internal resistance of the battery cell based on the battery health status and temperature information. For example, a perturbation observation method can be used to inject a small current pulse and measure the voltage response to calculate the AC internal resistance of the battery cell. The internal resistance voltage drop compensation amount of the battery cell is then calculated based on the AC internal resistance, and the second preset value is compensated based on the internal resistance voltage drop compensation amount. Furthermore, through real-time voltage feedback (i.e., real-time compensation of the second preset value), the conduction duty cycle of the NPN / PNP transistor is adjusted to achieve a balancing accuracy within ±5% and an energy transfer efficiency of 92%, significantly reducing heat loss (40% temperature drop) in traditional resistance balancing schemes and improving the overall usable capacity of the battery module 20.

[0032] Optionally, based on the above embodiments, see also... Figure 2 The battery protection board also includes a main control component 30. The main control component 30 includes a second discharge circuit 350. The main control component 30 is also used to acquire the battery health status of the battery module 20 after a preset time, and when the battery health information is greater than a third preset value, control the second discharge circuit 350 to reduce the voltage of the battery module 20 to a safe threshold.

[0033] Specifically, this embodiment of the invention also includes a storage protection mode. When the battery module 20 is detected to be fully charged for an extended period, it will discharge to reduce its voltage to a safe threshold for protection. Specifically, when the main control component 30 detects that the battery health status of the battery module 20 is still greater than a third preset value (which can be 95%) after a preset time (e.g., seven days), the second discharge circuit 350 reduces the voltage of the battery module 20 to the storage safety threshold of 3.9V. After discharge, it switches to a low-power monitoring state, waking up every 24 hours to perform voltage compensation, avoiding the risk of over-discharge due to self-discharge, effectively delaying battery degradation, and is expected to increase the cycle life of the battery cells by more than 22%.

[0034] It should be noted that the second discharge circuit 350 includes a third NPN transistor Q5 and a third PNP transistor Q6. The control electrode of the third NPN transistor Q5 is electrically connected to the main control component 30, the first electrode of the third NPN transistor Q5 is electrically connected to the first ground terminal, the second electrode of the third NPN transistor Q5 is electrically connected to the control electrode of the third PNP transistor Q6, the first electrode of the third PNP transistor Q6 is electrically connected to the positive terminal PACK+ of the battery module 20, and the second electrode of the third PNP transistor Q6 is electrically connected to the first ground terminal. It is understood that, as... Figures 1-4 As shown, in addition to the transistors mentioned above, the battery protection board also includes other resistors used for other protection or current limiting functions. The connection relationships and functions of these resistors are not described in detail in this embodiment of the invention. Those skilled in the art can set them as needed.

[0035] 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 battery protection board for unmanned aerial vehicles (UAVs), characterized in that, The battery protection board includes a fuel gauge assembly and a battery module; The battery module includes multiple battery cells connected in series; The fuel gauge assembly includes a first voltage detection circuit and a temperature detection circuit. The first voltage detection circuit is electrically connected to the battery module and is used to collect the voltage information of each battery cell in the battery module. The temperature detection circuit is disposed on the battery module and is used to detect the temperature information of the battery module. The fuel gauge assembly is connected to the flight controller and is used to obtain the voltage information and temperature information of the battery module according to the first voltage detection circuit and the temperature detection circuit, respectively, as well as the battery information of the battery module. Based on the voltage information, the temperature information and the battery information, the assembly determines the battery health status of the battery module and sends the battery health status to the flight controller.

2. The battery protection board according to claim 1, characterized in that, The step of determining the battery health status of the battery module based on the voltage information, the temperature information, and the battery information includes: extracting the voltage fluctuation rate of the battery module based on the voltage information, extracting the temperature rise slope of the battery module based on the temperature information, and extracting the historical cycle count of the battery module based on the battery information. Determine the full discharge capacity of the battery module, and calculate the capacity decay coefficient of the battery module based on the historical cycle count and the full discharge capacity. Determine the current information of the battery module, and determine the internal resistance growth coefficient of the battery module based on the temperature rise slope and the current information; The voltage consistency deviation coefficient of the battery module is determined based on the voltage fluctuation rate. A first weight for the capacity decay coefficient, a second weight for the internal resistance growth coefficient, and a third weight for the voltage consistency deviation coefficient are determined, and the battery health status of the battery module is determined based on the capacity decay coefficient, the first weight, the internal resistance growth coefficient, the second weight, the voltage consistency deviation coefficient, and the third weight.

3. The battery protection board according to claim 2, characterized in that, The battery health state is SOH, the capacity decay coefficient is α, the internal resistance growth coefficient is β, the voltage consistency deviation coefficient is γ, the first weight is ω1, the second weight is ω2, and the third weight is ω3. The formula for calculating the battery health status of the battery module is: SOH = ω1×α + ω2×β + ω3×γ.

4. The battery protection board according to claim 1, characterized in that, The battery protection board also includes a main control component, an over-discharge control circuit, and an overcharge control circuit. The main control component is connected to the fuel gauge component, the overcharge control circuit, and the over-discharge control circuit, respectively, and is used to obtain the battery health status of the battery module. When the battery health status is determined to be less than a first preset value, the main control component adjusts the maximum value of the charging voltage of the overcharge control circuit or adjusts the maximum value of the discharging voltage of the over-discharge control circuit.

5. The battery protection board according to claim 1, characterized in that, The battery protection board also includes a main control component and a first discharge circuit; The main control component includes a second voltage detection circuit; The second voltage detection circuit is used to detect the voltage information of each battery cell in the battery module; The main control component is connected to the first discharge circuit and is used to discharge the battery cell with larger voltage information when the difference between the voltage information of two battery cells is detected to be greater than a second preset value, so as to reduce the difference between the voltage information of the two battery cells.

6. The battery protection board according to claim 5, characterized in that, The battery module includes a first battery cell and a second battery cell. The first discharge circuit includes a first NPN transistor, a first PNP transistor, a second NPN transistor, and a second PNP transistor; The control electrode of the first NPN transistor is electrically connected to the first control terminal of the main control component, the first electrode of the first NPN transistor is electrically connected to the first ground terminal, the second electrode of the first NPN transistor is electrically connected to the control electrode of the first PNP transistor, the first electrode of the first PNP transistor is electrically connected to the positive electrode of the battery module, and the second electrode of the first PNP transistor is electrically connected to the negative electrode of the first battery cell. The control electrode of the second NPN transistor is electrically connected to the second control terminal of the main control component. The first electrode of the second NPN transistor is electrically connected to the first ground terminal. The second electrode of the second NPN transistor is electrically connected to the control electrode of the second PNP transistor. The first electrode of the second PNP transistor is electrically connected to the negative electrode of the first battery cell. The second electrode of the second PNP transistor is electrically connected to the first ground terminal.

7. The battery protection board according to claim 6, characterized in that, The main control component is used to control the second control terminal to send a conduction signal to turn on the second NPN transistor when it detects that the voltage information of the first battery cell is greater than that of the second battery cell, and the difference between the two is a second preset value, so as to discharge the first battery cell. At the same time, it controls the first PNP transistor to turn on to form a closed-loop discharge path.

8. The battery protection board according to claim 5, characterized in that, The main control component is also used to acquire the battery health status and temperature information of the battery module, and to calculate the AC internal resistance of the battery cell based on the battery health status and temperature information. The internal resistance voltage drop compensation amount of the battery cell is calculated based on the AC internal resistance, and the second preset value is compensated based on the internal resistance voltage drop compensation amount.

9. The battery protection board according to claim 1, characterized in that, The battery protection board also includes a main control component; The main control component includes a second discharge circuit; The main control component is also used to obtain the battery health status of the battery module after a preset time, and when the battery health information is greater than a third preset value, control the second discharge circuit to reduce the voltage of the battery module to a safe threshold.

10. The battery protection board according to claim 9, characterized in that, The second discharge circuit includes a third NPN transistor and a third PNP transistor; The control electrode of the third NPN transistor is electrically connected to the main control component, the first electrode of the third NPN transistor is electrically connected to the first ground terminal, the second electrode of the third NPN transistor is electrically connected to the control electrode of the third PNP transistor, the first electrode of the third PNP transistor is electrically connected to the positive terminal of the battery module, and the second electrode of the third PNP transistor is electrically connected to the first ground terminal.

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