Electric aircraft and battery control method of electric aircraft

Abstract

The invention provides an electric aircraft and a battery control method of the electric aircraft, and belongs to the technical field of product design, the electric aircraft comprises an unmanned aerial vehicle, a battery mounting groove is formed in the bottom of the unmanned aerial vehicle, a bottom plate is mounted at the bottom of the unmanned aerial vehicle, and a battery mounting frame is fixedly connected to the top of the bottom plate; a plurality of rows of cooling bases are installed in the battery installation frame, a plurality of batteries are installed in the cooling bases, a plurality of first connecting pipes are installed on the two sides of the battery installation frame, a second connecting pipe is connected to each first connecting pipe, a cooling liquid box is installed in the unmanned aerial vehicle, and a semiconductor chilling plate is installed on one side of the cooling liquid box. And the other side of the cooling liquid tank is connected with an input pipe. The problems that an integral cooling structure is mostly adopted in a traditional scheme, the heat exchange contact area is limited, accurate cooling according to needs cannot be achieved, the cooling efficiency is low, and a large amount of energy is wasted are solved; meanwhile, differential cooling strategies for different flight working conditions such as cruising, hovering and high load are lacked, and the temperature control precision is difficult to guarantee.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of product design, and particularly relates to an electric aircraft and a battery control method of the electric aircraft. BACKGROUND

[0002] As a flexible and efficient electric aircraft, the unmanned aerial vehicle has been widely used in aerial photography surveying and mapping, power inspection, emergency rescue, logistics distribution and other fields. With the expansion of application scenarios, the unmanned aerial vehicle has higher requirements for endurance, flight stability and operation reliability. The working performance and thermal management level of the power battery system as the core power source of the unmanned aerial vehicle directly determine the flight safety and operation efficiency of the unmanned aerial vehicle. Currently, the mainstream unmanned aerial vehicle adopts a lithium power battery. The battery has high energy density, but is sensitive to working temperature. Too high or too low temperature will cause capacity attenuation, internal resistance increase and even safety accidents such as thermal runaway. Therefore, efficient battery thermal management and precise control have become one of the key cores of the development of the unmanned aerial vehicle technology.

[0003] The unmanned aerial vehicle battery control and cooling have some defects. In the cooling aspect, the traditional scheme mostly adopts a whole cooling structure, the heat exchange contact area is limited, and precise cooling on demand cannot be achieved. Not only is the cooling efficiency low, but also a large amount of energy is wasted. At the same time, there is no differentiated cooling strategy for different flight conditions such as cruising, hovering and high load. The temperature control precision is difficult to guarantee. Therefore, an electric aircraft and a battery control method of the electric aircraft are proposed. SUMMARY

[0004] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title. Such simplifications or omissions cannot be used to limit the scope of the present application.

[0005] In view of the following technical problems in the prior art: the traditional scheme mostly adopts a whole cooling structure, the heat exchange contact area is limited, and precise cooling on demand cannot be achieved. Not only is the cooling efficiency low, but also a large amount of energy is wasted. At the same time, there is no differentiated cooling strategy for different flight conditions such as cruising, hovering and high load. The temperature control precision is difficult to guarantee.

[0006] To solve the above technical problems, the present application provides the following technical solutions: An electric aircraft, comprising a drone, a battery mounting groove is formed in the bottom of the drone, a bottom plate is mounted on the bottom of the drone, a battery mounting frame is fixedly connected to the top of the bottom plate, a plurality of rows of cooling seats are mounted in the battery mounting frame, a plurality of batteries are mounted in the cooling seats, a plurality of connecting pipes one are mounted on the two sides of the battery mounting frame, a connecting pipe two is connected to each connecting pipe one, a cooling liquid tank is mounted in the drone, a semiconductor refrigeration sheet is mounted on one side of the cooling liquid tank, an input pipe is connected to the other side of the cooling liquid tank, a main pipe one is connected to the input pipe, a plurality of branch pipes one are connected to the main pipe one, a conveying pipe is connected to each branch pipe one, the conveying pipe is connected to the corresponding connecting pipe two, a return pipe is connected to the top of the drone, a main pipe two is connected to the other end of the return pipe, a plurality of branch pipes two are connected to the main pipe two, and the plurality of branch pipes two are connected to the corresponding connecting pipes two on the right side.

[0007] Further, an electromagnetic valve one is mounted on each branch pipe one, an electromagnetic valve two is mounted on each branch pipe two on the right side, and a temperature measuring element is mounted at the positions corresponding to each battery and the return pipe.

[0008] Further, the cooling seat is composed of a plurality of connected ring bodies, the ring bodies are matched with the batteries, the cooling seat is hollow, and the connecting pipe one is connected to the cooling seat.

[0009] A battery control method, comprising the following steps: S1: battery state initialization and monitoring system startup, confirming battery core parameters, starting distributed temperature measurement module, detecting battery voltage, current SOC, and verifying signal connection;

[0010] S2: cooling system pre-startup and parameter calibration, starting semiconductor refrigeration sheet, circulating pump pre-running air, testing electromagnetic valve on-off, and calibrating cooling threshold parameters;

[0011] S3: precise cooling branch control based on temperature zoning, dividing independent cooling zones, controlling electromagnetic valves according to temperature threshold, and flexibly distributing multi-zone flow;

[0012] S4: real-time feedback and dynamic adjustment in the cooling process, establishing a dynamic feedback mechanism, adapting to working condition cooling strategy, and responding to local heating adjustment;

[0013] S5: abnormal state recognition and emergency treatment, monitoring multiple abnormal states, executing emergency response in stages, and recording abnormal information;

[0014] S6: residual heat treatment after shutdown and system reset, continuously cooling residual heat, shutting down system core components, and resetting and checking the system.

[0015] Further, the dynamic feedback mechanism takes 1 second as the data acquisition period, and calculates the temperature deviation value (current temperature-preset threshold) of each cooling partition in real time;

[0016] When the temperature deviation value is 0-5℃, the corresponding branch electromagnetic valve opening degree is 30%-50%; when the temperature deviation value is 5-10℃, the electromagnetic valve opening degree is 60%-80%;

[0017] When the temperature deviation value is greater than 10℃, the electromagnetic valve is fully opened (opening degree 100%), and the circulating pump speed is increased by 1.2-1.5 times.

[0018] Further, the working condition cooling strategy is adapted to the cruising, hovering and high load three core working conditions of the electric aircraft, and the corresponding cooling thresholds are set to 35℃, 40℃ and 45℃ respectively.

[0019] Further, the multiple abnormal states include battery monomer over-temperature (temperature≥55℃), battery voltage abnormality (deviation from rated voltage ±10%), electromagnetic valve on-off fault, and cooling liquid level lower than the preset minimum value.

[0020] Further, the first level response: the triggering condition is over-temperature abnormality and voltage abnormality, at this time, the power supply of the corresponding battery branch is immediately cut off, the maximum flow of the partition cooling branch is opened, the circulating pump is operated at full load, and a red warning signal is sent to the ground terminal through the wireless communication module;

[0021] The second level response: the triggering condition is valve abnormality and liquid level abnormality, the flight power of the aircraft is reduced by 30%, the return route is automatically planned, and a yellow warning signal is sent to the ground terminal;

[0022] All abnormal information including abnormal type, occurrence time, corresponding battery number and real-time working condition parameters are stored in the built-in storage module of the unmanned aerial vehicle, which supports subsequent export and troubleshooting.

[0023] The beneficial effects of the present application are:

[0024] 1. The cooling seat of the present application adopts a ring body structure matched with the battery, maximizes the heat exchange contact surface, cooperates with distributed temperature measurement and independent branch control, realizes on-demand cooling, effectively avoids energy waste, the dynamic feedback mechanism and the segmented PID control ensure that the temperature fluctuation is controlled within ±2℃, the cooling efficiency is improved by more than 40%, and the 1 second optimal acquisition period balances the control precision and system algorithm load;

[0025] The differential cooling threshold design for the cruising, hovering and high load three core working conditions reduces the cooling system energy consumption, not only ensures that the battery works in the optimal temperature interval under each working condition, but also improves the battery cycle life, and realizes flight range gain by reducing cooling energy consumption.

[0026] 2. The battery control flow of the application covers the whole cycle from start initialization, running adjustment, abnormality treatment to shutdown and waste heat recovery;

[0027] Precise identification and anti-interference processing of multiple abnormal states, and hierarchical emergency response can quickly suppress fatal risks and ensure safe return under controllable risks;

[0028] In addition, the full storage and export function of abnormal information provides complete data support for fault tracing, improves the efficiency of safety accident handling, significantly reduces economic losses, and further enhances the reliability of equipment operation through the design of state verification and system reset in the whole process.

[0029] Other features and advantages of the application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application. The objects and other advantages of the application can be achieved and obtained by the structure specifically pointed out in the specification and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor. Among them:

[0031] Figure 1 It is a schematic diagram of the overall structure of the embodiment of the application;

[0032] Figure 2 It is a schematic diagram of the structure of another perspective and removing the fixed block of the embodiment of the application;

[0033] Figure 3 It is a schematic diagram of the top view structure of the embodiment of the application;

[0034] Figure 4 It is a schematic diagram of the Figure 3 A-A cross-sectional structure of the embodiment of the application;

[0035] Figure 5 It is a battery control method flowchart of the embodiment of the application;

[0036] Reference signs: 1, unmanned aerial vehicle; 2, battery mounting groove; 3, bottom plate; 4, battery mounting frame; 5, battery; 6, cooling seat; 7, connecting pipe one; 8, connecting pipe two; 9, cooling liquid tank; 10, semiconductor refrigeration piece; 11, input pipe; 12, return pipe; 13, main pipe one; 131, branch pipe one; 14, conveying pipe. DETAILED DESCRIPTION

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0038] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0040] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0041] Reference Figures 1-5The embodiment of the present application provides an electric aircraft, which comprises a drone 1, a battery mounting groove 2 is formed in the bottom of the drone 1, a bottom plate 3 is mounted at the bottom of the drone 1, a battery mounting frame 4 is fixedly connected to the top of the bottom plate 3, a plurality of rows of cooling seats 6 are mounted in the battery mounting frame 4, a plurality of batteries 5 are mounted in the cooling seats 6, a plurality of connecting pipes one 7 are mounted on the two sides of the battery mounting frame 4, a connecting pipe two 8 is connected to each connecting pipe one 7, a cooling liquid tank 9 is mounted in the drone 1, a semiconductor refrigerating fin 10 is mounted on one side of the cooling liquid tank 9, an input pipe 11 is connected to the other side of the cooling liquid tank 9, the input pipe 11 is connected with a main pipe one 13, a plurality of branch pipes one 131 are connected to the main pipe one 13, a conveying pipe 14 is connected to each branch pipe one 131, the conveying pipe 14 is connected with a corresponding connecting pipe two 8, a return pipe 12 is connected to the top of the drone 1, the other end of the return pipe 12 is connected with a main pipe two, a plurality of branch pipes two are connected to the main pipe two, the branch pipes two are connected with corresponding connecting pipes two 8 on the right side, the semiconductor refrigerating fin 10 cools the cooling liquid in the cooling liquid tank 9, the low-temperature cooling liquid is driven by a pump (not shown in the figure) and is conveyed into the connecting pipe two 8 and the connecting pipe one 7 of each cooling seat 6 through the input pipe 11, the main pipe one 13, the branch pipe one 131 and the conveying pipe 14, when the cooling liquid flows through the hollow cooling seat 6, the heat generated by the battery 5 during work is absorbed, the temperature is increased, the high-temperature cooling liquid after heat absorption flows out from the connecting pipe on the other side of the battery mounting frame 4, returns to the cooling liquid tank 9 through the connecting pipe two 8 on the right side, the branch pipe two, the main pipe two and the return pipe 12, so that a complete cooling cycle is completed.

[0042] An electromagnetic valve one is mounted on each branch pipe one 131, and an electromagnetic valve two is mounted on each branch pipe two on the right side, by independently controlling the electromagnetic valve one on each branch pipe one 131 and the electromagnetic valve two on the branch pipe two on the right side, accurate on-off control of each cooling seat 6 or each row of battery cooling branch can be realized, when the temperature of a group of batteries is low and cooling is not needed, the corresponding electromagnetic valve one and electromagnetic valve two can be closed, the cooling liquid flow of the branch is cut off, on-demand cooling is realized, and therefore the system energy consumption is optimized.

[0043] The cooling seat 6 is composed of a plurality of connected ring bodies, the ring body is matched with the battery 5, the cooling seat 6 is hollow, the connecting pipe one 7 is connected with the cooling seat 6, the cooling seat 6 is designed as a connected ring body structure matched with the outer shape of the cylindrical battery 5, can wrap the side surface of the battery 5 with the maximum area, forms a high-efficiency heat exchange contact surface, and the hollow cavity body serves as a flow channel of the cooling liquid, when the low-temperature cooling liquid flows through the hollow cavity body, the heat on the surface of the battery 5 is rapidly conducted and taken away through the wall surface of the cooling seat 6 made of high-thermal-conductivity material, and therefore high-efficiency heat dissipation is realized.

[0044] A battery control method, S1: battery state initialization and monitoring system starts, confirms the battery core parameters, starts the distributed temperature measurement module, detects the battery voltage and current SOC, verifies the signal connection, the core parameters include the battery rated capacity C n , rated voltage U n , internal resistance R0, the distributed temperature measurement module uses NTC thermistor array, arranged at the battery monomer gap and bus, SOC (remaining capacity) uses ampere-hour integral method combined with Kalman filter correction calculation, the formula is:

[0045] SOC(t) = SOC0- ∫0 t (I(τ)η(τ) / C n ) dτ+ K·ΔU

[0046] SOC0 is the initial remaining capacity, I(τ) is the battery current at τ (positive for charging, negative for discharging), η(τ) is the charging and discharging efficiency, K is the voltage correction coefficient, ΔU is the deviation of the current voltage from the rated voltage; The signal connection verification uses CRC-32 verification algorithm to ensure that the temperature measurement, voltage and current signal transmission accuracy is ≥99.9%;

[0047] S2: pre-starting of cooling system and parameter calibration, starting semiconductor refrigerating sheet, circulating pump pre-running to exhaust air, testing electromagnetic valve on-off, calibrating cooling threshold parameter, the semiconductor refrigerating sheet selects TEC1-12706 model, the initial refrigeration power P0=30W is set during pre-starting, the refrigeration temperature is preliminarily stabilized through PID adjustment, the circulating pump pre-running time T p =60s, the exhaust air judgment standard is that the pump outlet pressure fluctuation is ≤0.02MPa, the electromagnetic valve on-off test adopts PWM signal driving with 50% duty cycle, the on-off response time is ≤10ms, the cooling threshold calibration is completed through high-low temperature box simulation experiment, and the calibration formula is:

[0048] T th = T0+ α·P load

[0049] Wherein, T th is the calibrated cooling threshold, T0 is the basic threshold (25℃), α is the working condition coefficient (0.05℃ / W), P load is the maximum heat power of the battery;

[0050] S3: precise cooling branch control based on temperature zoning, dividing independent cooling zones, controlling electromagnetic valves according to temperature threshold, flexible distribution of multi-zone flow, dividing into 3 independent cooling zones according to the physical layout of the battery pack, each zone corresponds to a group of electromagnetic valves and temperature measurement units, the flow distribution adopts proportional integral control, and the flow distribution coefficient k i satisfies

[0051]

[0052] T i T thi is the cooling threshold of the ith partition, ensuring that the partition with more heat generates more cooling flow;

[0053] S4: Real-time feedback and dynamic adjustment of the cooling process, establishing a dynamic feedback mechanism, adapting to the cooling strategy under different working conditions, and responding to local heating adjustments. The feedback mechanism uses closed-loop control to ensure that temperature fluctuations are controlled within ±2℃. The working condition adaptation is based on the flight mode signal output by the flight controller, which switches the cooling strategy in real time.

[0054] S5: Abnormal state identification and emergency handling, monitoring multiple abnormal states, executing emergency responses in stages, recording abnormal information, and using multi-parameter fusion judgment to avoid single parameter misjudgment. The emergency response is graded according to risk levels (Level 1 is fatal risk, Level 2 is controllable risk).

[0055] S6: After shutdown, the residual heat is treated and the system is reset. The core components of the system are turned off, the system is reset and the components are checked, and the continuous cooling time T r According to the battery temperature before shutdown, the formula is:

[0056] T r = (T en d - T a ) / β

[0057] Where T en d is the battery temperature before shutdown, T a is the ambient temperature, and β is the cooling rate (2℃ / min), ensuring that the battery temperature drops to within +5℃ of the ambient temperature before the system is turned off.

[0058] This process covers the entire process from startup to shutdown of battery control, with temperature control accuracy improved to ±2℃, abnormal response time ≤1s, and battery cycle life improved by more than 25%, ensuring the safety and reliability of electric aircraft flight.

[0059] The dynamic feedback mechanism has a data acquisition period of 1 second, and calculates the temperature deviation value (current temperature - preset threshold) of each cooling partition in real time.

[0060] When the temperature deviation value is 0-5℃, the corresponding branch electromagnetic valve opening is 30%-50%. When the temperature deviation value is 5-10℃, the electromagnetic valve opening is 60%-80%.

[0061] When the temperature deviation value is greater than 10℃, the electromagnetic valve is fully open (opening 100%) and the circulating pump speed is increased by 1.2-1.5 times.

[0062] Through simulation and experimental verification, when the acquisition period is >1s, the temperature deviation accumulation can reach 3-4℃, leading to untimely cooling; when the acquisition period is <1s, the system computing power load will be increased (CPU occupancy rate will be increased by more than 15%), affecting the normal work of other flight control systems, so 1s is determined as the optimal acquisition period, achieving the balance between control precision and system load.

[0063] Based on fluid mechanics and heat transfer theory, the cooling flow Q and the electromagnetic valve opening θ are linearly positively correlated, i.e. Q=k·θ (k is the flow coefficient, unit L / (s·%)); while the heat dissipation power P a and the cooling flow are related as follows:

[0064] P a = c p ·ρ·Q·ΔT

[0065] where c p is the specific heat capacity of the cooling liquid (J / (kg·℃)), ρ is the density of the cooling liquid (kg / m³), ΔT is the temperature difference between the inlet and outlet of the cooling liquid, and through experimental calibration, when the temperature deviation ΔT=0-5℃, the flow corresponding to 30%-50% opening of the required heat dissipation power can meet the demand;

[0066] When the deviation is 5-10℃, the flow needs to be increased to 60%-80%;

[0067] When the deviation is >10℃, the maximum flow is required for heat dissipation, and the circulating pump speed is increased to increase the flow rate of the cooling liquid, to strengthen the convective heat transfer effect;

[0068] The circulating pump speed n and the flow Q satisfy the similarity law Q1 / Q2 = n1 / n2, when the speed is increased by 1.2-1.5 times, the flow is synchronously increased by 1.2-1.5 times, and the heat dissipation power is synchronously increased, which can quickly reduce the battery temperature;

[0069] The upper limit of the speed increase is set to 1.5 times, because when the speed is increased by more than this multiple, the efficiency of the pump will decrease (the efficiency decreases from 75% to below 50%), and the noise and energy consumption will significantly increase (the energy consumption is proportional to the cube of the speed, i.e. P∝n³).

[0070] The segmented PID control algorithm is adopted, different PID parameters (proportional coefficient K p , integral coefficient K i , and differential coefficient K d ) are used for different deviation intervals, which are as follows:

[0071] ΔT∈[0,5℃] : K p =5, K i =0.1, K d =0.5 (to avoid over-regulation)

[0072] ΔT∈[5,10℃] : K p = 8, K i = 0.2, K d = 0.3 (faster response)

[0073] ΔT > 10℃ : K p = 12, K i = 0.3, K d = 0.1 (emergency cooling);

[0074] The dynamic feedback mechanism can make the temperature control response time ≤ 1s, the temperature deviation quickly converges to ±2℃, compared with the traditional fixed parameter control, the cooling efficiency is improved by more than 40%, and the system energy consumption is reduced by 15%-20%, avoiding the problems of insufficient cooling or excessive cooling.

[0075] The working condition cooling strategy is suitable for cruising, hovering and high load of the electric aircraft, and the corresponding cooling thresholds are set to 35℃, 40℃ and 45℃ respectively;

[0076] Analysis of battery heating characteristics in three core working conditions:

[0077] Cruising condition: the electric aircraft flies at a constant speed, the battery output power P1 = 0.4-0.6P n (P n is the rated power), the heating power P h1 = 5-10W, the battery temperature rises slowly, and the steady-state temperature is about 30-32℃;

[0078] Hovering condition: the aircraft is vertically parked, the propeller lift is equal to the gravity, the battery output power P2 = 0.6-0.8P n , the heating power P h2 = 10-15W, and the steady-state temperature is about 35-38℃;

[0079] High load condition: the aircraft accelerates, climbs or carries heavy load, the battery output power P3 = 0.8-1.0P n , the heating power P h2 = 15-25W, and the steady-state temperature can reach 40-42℃.

[0080] Experimental basis for setting the cooling threshold: simulate three working conditions by high and low temperature environmental chamber, test the performance parameters (capacity, internal resistance, cycle life) of the battery at different temperatures, the results show that:

[0081] Under cruising condition, when the threshold is set to 35℃, the battery capacity retention rate is ≥98%, and the internal resistance growth is ≤2% / 100 cycles;

[0082] Under hovering condition, when the threshold is set to 40℃, the above performance parameters are optimal;

[0083] Under high load conditions, the threshold can be raised to 45°C (short-term high temperature does not affect the safety of the battery, and can reduce the cooling energy consumption), if it exceeds 45°C, the battery capacity decay rate increases by more than 50%, and the internal resistance increases by ≥5% / 100 cycles.

[0084] Working condition recognition and threshold switching mechanism: Obtain flight parameters (such as flight speed, height, acceleration, motor output power) through the CAN bus of the flight controller, establish a working condition recognition model:

[0085] Mode = f(v, a, P motor )

[0086] Among them, v is the flight speed, a is the acceleration, P motor is the motor output power, when v∈[10-30m / s], a∈[-0.5,0.5]m / s², P motor ∈[0.4-0.6]P n , it is determined that it is a cruising condition;

[0087] When v=0, a∈[-1,1]m / s², P motor ∈[0.6-0.8]P n , it is determined that it is a hovering condition;

[0088] When a>0.5m / s², P motor ∈[0.8-1.0]P n , it is determined that it is a high load condition, and the threshold switching response time is ≤0.5s.

[0089] In this way, the differentiated cooling threshold reduces the cooling system energy consumption by 20%-30% (cruising condition does not require high-power cooling), while ensuring that the battery works in the optimal temperature range under each working condition, the battery cycle life is improved by more than 25%, and the flight endurance is improved by 5%-8% (the endurance gain brought by the reduction of cooling energy consumption).

[0090] The multiple abnormal states include battery cell overtemperature (temperature≥55℃), battery voltage anomaly (deviation from rated voltage ±10%), electromagnetic valve on-off fault, and cooling liquid level below the preset minimum value;

[0091] The hazards and determination criteria of each abnormal state are as follows:

[0092] Battery cell over-temperature (≥55℃): The thermal runaway threshold temperature of power battery (such as lithium polymer battery) is about 60-65℃. When the cell temperature is ≥55℃, the SEI film inside the battery begins to decompose, the internal resistance increases sharply, the heat release rate increases, and if not handled in time, thermal runaway can be triggered within 10-15s. Therefore, 55℃ is set as the over-temperature abnormal threshold, and a distributed temperature measurement module is used for real-time monitoring, with one temperature measurement point corresponding to each cell to avoid missing local over-temperature.

[0093] Battery voltage abnormality (deviation from rated voltage ±10%): The rated voltage U n of the battery is ±10% as the safe voltage range. When the voltage is >1.1U n , the battery is in an overcharged state, which can easily cause electrolyte decomposition and gas expansion. When the voltage is <0.9U n , the battery is in an over-discharged state, which can easily cause lithium precipitation and damage the battery structure.

[0094] The voltage abnormality determination formula is:

[0095] |U i - U n | / U n ≥ 10%

[0096] Wherein, U i is the real-time voltage of the i-th battery cell, which is monitored by a voltage collection chip (accuracy ±0.01V).

[0097] Electromagnetic valve on-off fault: By comparing the feedback signal (feedback high level when powered on, feedback low level when powered off) of the electromagnetic valve with the driving signal, if the driving signal is "on" but the feedback signal is "off", or the driving signal is "off" but the feedback signal is "on", and the duration is ≥2s, it is determined as a fault. The fault will cause the cooling branch to fail to normally switch, causing local overheating or cooling failure.

[0098] Cooling liquid level is lower than the preset minimum value: The preset minimum value L min is determined according to the minimum circulation requirement of the cooling circuit, and the formula is:

[0099] L min = V net / S

[0100] Wherein, V net is the minimum circulation volume of the cooling circuit (calculated by three-dimensional modeling), and S is the cross-sectional area of the installation position of the liquid level sensor; When the liquid level is lower than L min , the circulating pump will be in idle running, and the cooling flow will be reduced by more than 90%, causing the cooling system to fail.

[0101] Anti-interference processing of abnormal signal: adopt optical coupling isolation circuit to transmit abnormal signal, avoid misjudgment caused by electromagnetic interference (strong electromagnetic interference will be generated when electric aircraft motor works), at the same time, adopt sliding window filtering algorithm (window size is 5) to process monitoring data, formula is:

[0102] X = (X1+ X2+ X3+ X4+ X5) / 5 wherein, X is filtered data, X1-X5 is data of continuous 5 acquisition periods, misjudgment rate caused by random interference can be reduced to below 0.1%.

[0103] Comprehensively cover core abnormal risk points in battery control process, accurate determination standard and strong anti-interference ability, abnormal identification accuracy is greater than or equal to 99.9%, provide reliable basis for subsequent grading emergency response, reduce safety accident rate.

[0104] First level response: trigger condition is over-temperature abnormality and voltage abnormality, at this time, immediately cut off power supply of corresponding battery branch, open maximum flow of cooling branch of the partition, circulating pump runs at full load, send red warning signal to ground terminal through wireless communication module;

[0105] Second level response: trigger condition is valve abnormality and liquid level abnormality, control aircraft to reduce flight power by 30%, automatically plan return route, send yellow warning signal to ground terminal;

[0106] All abnormal information including abnormal type, occurrence time, corresponding battery number and real-time working condition parameter are stored in built-in storage module of unmanned aerial vehicle, support subsequent export and troubleshooting.

[0107] Logical basis of grading response: risk level division based on abnormal state--first level abnormality (over-temperature and voltage abnormality) is fatal risk, if not immediately handled, it can cause battery thermal runaway or power interruption within 10-15s, leading to aircraft crash; second level abnormality (valve and liquid level abnormality) is controllable risk, it will not directly cause fatal accident in short time, but will affect cooling effect, need to reduce load and return for processing, realize balance between risk and processing cost.

[0108] Specific execution logic of first level response:

[0109] Cut off power supply of corresponding battery branch: adopt electronic fuse (response time is less than or equal to 1ms) to cut off fault branch, avoid fault spreading to other battery monomers; after cutting off, other normal branches are kept powered to ensure that aircraft still has part of power (if only single branch fault), improve flexibility of emergency disposal.

[0110] Maximum flow control of cooling branch: control corresponding partition electromagnetic valve to be fully opened (opening degree is 100%), circulating pump speed is improved to maximum (1.5 times rated speed), heat dissipation power reaches maximum value P aamx, the formula is:

[0111] P aamx = c p ·ρ·Q max ·ΔT max

[0112] wherein Q max is the maximum cooling flow, ΔT max is the maximum allowable temperature difference (15℃), which can quickly reduce the temperature of the fault branch battery.

[0113] Red warning signal: sent by 4G / 5G wireless communication module, signal format is "abnormal type-battery number-real-time temperature / voltage-time stamp", transmission rate ≥100kb / s, to ensure real-time reception by ground terminal, the warning signal is continuously sent until the fault is removed or the aircraft lands.

[0114] The specific execution logic of the secondary response is:

[0115] Reduce flight power by 30%: the power adjustment formula is P new = P oi d × 70%, reducing power can reduce battery heating power (heating power is proportional to the square of power, i.e. P h ∝P²), to alleviate the temperature rise pressure caused by cooling system failure; at the same time, 70% of the power can ensure the basic flight attitude control and homing ability of the aircraft.

[0116] Yellow warning signal: the signal format is consistent with the red warning, which is used to remind ground operators to pay attention to the aircraft state and prepare for landing.

[0117] Abnormal information storage mechanism: the storage medium uses an industrial-grade SD card, and the storage period is the full amount of data from 10s before the abnormality occurs to 10s after the processing is completed, and the data format is CSV file, which is convenient for subsequent data analysis and fault tracing with MATLAB and other tools; at the same time, data export is supported through USB interface or wireless communication.

[0118] The hierarchical response strategy realizes the precise control of risks, the first-level response can quickly contain fatal risks, the second-level response can guarantee the safe return of the aircraft, and the abnormal information storage provides complete data support for fault troubleshooting, which improves the efficiency of safety accident handling and reduces economic losses.

[0119] It should be understood that, in the development of any actual implementation, as in any engineering or design project, a large number of implementation decisions can be made. Such development efforts can be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, they will be a routine work of design, manufacture and production without much experiment.

[0120] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. An electric aircraft, comprising a drone (1), characterized in that, The drone (1) has a battery mounting slot (2) at its bottom, a base plate (3) at its bottom, a battery mounting frame (4) fixedly connected to the top of the base plate (3), a number of cooling seats (6) installed in the battery mounting frame (4), a number of batteries (5) installed in the cooling seats (6), a number of connecting pipes (7) installed on both sides of the battery mounting frame (4), and a connecting pipe (8) connected to each connecting pipe (7). The drone (1) has a coolant tank (9), and a semiconductor cooling chip (1) is installed on one side of the coolant tank (9). 0), the coolant tank (9) is connected to an input pipe (11) on the other side, the input pipe (11) is connected to a main pipe (13), the main pipe (13) is connected to several branch pipes (131), each branch pipe (131) is connected to a delivery pipe (14), the delivery pipe (14) is connected to the corresponding connecting pipe (8), the top of the drone (1) is connected to a return pipe (12), the other end of the return pipe (12) is connected to a main pipe (2), the main pipe (2) is connected to several branch pipes (2), and the several branch pipes (2) are connected to the corresponding connecting pipe (8) on the right side.

2. An electric aircraft according to claim 1, characterized in that: Solenoid valve 1 is installed on each of the branch pipes 1 (131), solenoid valve 2 is installed on each of the branch pipes 2 on the right side, and temperature measuring devices are installed on the coolant tank (9), the corresponding position of each battery (5), and the return pipe (12).

3. An electric aircraft according to claim 1, characterized in that: The cooling seat (6) is composed of several connected rings, which are matched with the battery (5). The cooling seat (6) is hollow, and the connecting pipe (7) is connected to the cooling seat (6).

4. A battery control method using the electric aircraft described in any one of claims 1-3, characterized in that, Includes the following steps: S1: The battery status initialization and monitoring system starts, confirms core battery parameters, starts the distributed temperature measurement module, detects battery voltage and current SOC, and verifies signal connections; S2: Cooling system pre-start and parameter calibration, start the thermoelectric cooler, pre-run the circulating pump to purge air, test the solenoid valve on / off state, and calibrate the cooling threshold parameters; S3: Precise cooling branch control based on temperature zones, dividing the system into independent cooling zones, controlling solenoid valves according to temperature thresholds, and flexibly distributing flow across multiple zones; S4: Real-time feedback and dynamic adjustment of the cooling process, establishing a dynamic feedback mechanism to adapt to the cooling strategy under operating conditions and adjust for localized heat generation; S5: Abnormal Status Identification and Emergency Handling; monitors multiple abnormal statuses, executes tiered emergency responses, and records abnormal information; S6: After shutdown, residual heat treatment and system reset, continuous cooling to treat residual heat, shutdown of core system components, system reset and component inspection.

5. The electric aircraft and its battery control method according to claim 4, characterized in that: The dynamic feedback mechanism uses a 1-second data acquisition cycle to calculate the temperature deviation of each cooling zone in real time. When the temperature deviation value is a preset value, the opening degree of the corresponding branch solenoid valve is within the preset range; when the temperature deviation value is a preset value, the opening degree of the solenoid valve is within the preset range. When the temperature deviation exceeds the preset value, the solenoid valve opens fully and the circulation pump speed increases.

6. The battery control method according to claim 5, characterized in that: The operating condition cooling strategy is adapted to the three core operating conditions of electric aircraft: cruise, hovering, and high load, with corresponding cooling thresholds set at 35℃, 40℃, and 45℃, respectively.

7. The battery control method according to claim 5, characterized in that: The various abnormal states include battery cell overheating, abnormal battery voltage, solenoid valve on / off failure, and coolant level below the preset minimum value.

8. The battery control method according to claim 5, characterized in that: Level 1 Response: The triggering conditions are abnormal temperature or abnormal voltage. At this time, the power supply to the corresponding battery branch is immediately cut off, the maximum flow rate of the cooling branch of that zone is turned on, the circulation pump runs at full load, and a red warning signal is sent to the ground terminal through the wireless communication module. Level 2 response: The triggering conditions are valve abnormality and liquid level abnormality. The aircraft is controlled to reduce flight power, automatically plan the return route, and send a yellow warning signal to the ground terminal. All anomaly information, including anomaly type, occurrence time, corresponding battery number, and real-time operating parameters, is stored in the drone's built-in storage module, supporting subsequent export and troubleshooting.

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