Power device control method and system of electric vehicle

Abstract

The invention discloses a control method and system for a power device of an electric vehicle, and belongs to the technical field of power device control, and the control method specifically comprises the steps that the real-time temperature of the power device of the electric vehicle is monitored in real time, and when the real-time temperature is lower than an appropriate temperature upper limit H, the kinetic energy recovery or range extending power generation function of the vehicle is controlled to be started; when the real-time temperature of the power device is higher than the upper temperature limit H, a heat management system of the vehicle is controlled to be started, the power device is cooled, and when the real-time temperature is reduced to be lower than H, the heat management system is closed, and the kinetic energy recovery or range extending power generation function of the vehicle is controlled to be started; when the vehicle charges the power device through kinetic energy recovery or extended range power generation and when the real-time temperature rises to H, the current real-time temperature rising speed v is calculated according to the instantaneous slope of the current coordinate point, the heat increasing speed V is calculated according to the temperature rising speed, and the cooling power P of the heat management system is calculated according to the heat increasing speed V; according to the invention, stable control of the electric vehicle power device is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power device control, and in particular to a power device control method and system for an electric vehicle. Background Art

[0002] With the enhancement of environmental awareness and the development of new energy technologies, electric vehicles are becoming more and more popular as a clean and efficient means of transportation. However, during the operation of electric vehicles, especially when starting kinetic energy recovery and extended range charging, their power units will generate a lot of heat. If the heat cannot be dissipated in a timely and effective manner, it will not only affect the performance of the vehicle, but may also damage key components such as batteries and shorten their service life. Therefore, how to effectively control the temperature of the electric vehicle power unit and ensure its stable operation within an appropriate operating temperature range has become an urgent problem to be solved.

[0003] Existing electric vehicle power unit control methods mostly rely on simple temperature monitoring and alarm mechanisms. When the temperature exceeds the preset safety value, measures are taken to cool down or alert the user. Although this method can avoid damage to the equipment due to high temperature to a certain extent, it lacks real-time response and precise control of temperature changes. It usually uses a fixed-level cooling power. When the cooling power is insufficient, it cannot effectively suppress the heat generated by the power unit. When the cooling power is too high, it wastes the precious electric energy of the electric vehicle and cannot achieve the optimal energy efficiency ratio and user experience.

[0004] Therefore, it is particularly important to develop a new control method that can automatically adjust the working mode according to the real-time temperature change of the power unit and start the thermal management system to cool down when necessary. This method should not only be able to accurately monitor and predict the temperature change trend of the power unit, but also be able to intelligently select the most appropriate cooling strategy according to different working conditions, so as to achieve the goal of energy saving and emission reduction. Summary of the invention

[0005] The purpose of the present invention is to provide a method and system for controlling a power device of an electric vehicle to solve the following technical problems: Existing electric vehicle power unit control methods usually use a fixed-gear cooling power. When the cooling power is insufficient, the heat generated by the power unit cannot be effectively suppressed. When the cooling power is too high, the precious electric energy of the electric vehicle is wasted.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for controlling a power device of an electric vehicle comprises the following steps: Real-time monitoring of the real-time temperature of the electric vehicle power device, when the real-time temperature is lower than the upper temperature limit H, control to start the vehicle's kinetic energy recovery function or range-extending power generation function; When the real-time temperature of the power unit is higher than the upper temperature limit H, the vehicle thermal management system is controlled to start and cool the power unit. When the real-time temperature drops below H, the thermal management system is turned off and the vehicle's kinetic energy recovery function or range-extending power generation function is controlled to start; When the vehicle charges the power device through kinetic energy recovery or range-extending power generation, during the charging process, if the real-time temperature change of the electric vehicle power device is monotonically increasing, the real-time temperature change of the power device is plotted as a power device change curve. When the real-time temperature of the power device rises to H, the current real-time temperature rise rate v of the power device is calculated according to the instantaneous slope of the current coordinate point, the heat increase rate V is calculated according to the temperature rise rate, and the cooling power P of the thermal management system is calculated according to the heat increase rate V, and the cooling power P is used as the working power of the current thermal management system.

[0007] As a further solution of the present invention: the power device includes an electric drive system, an energy storage system, a power electronic conversion system and a vehicle control system.

[0008] As a further solution of the present invention: during the driving of the electric vehicle, the temperature of the vehicle battery is monitored in real time, and the average temperature per unit mileage increase is calculated, and the remaining distance before the battery temperature exceeds the suitable temperature upper limit H is calculated based on the average temperature. When the remaining distance is lower than a preset threshold, the owner is prompted to switch the power mode from battery mode to extended-range mode.

[0009] As a further solution of the present invention: during the driving of the electric vehicle, the remaining power of the electric vehicle battery is monitored in real time, and the average power consumed per unit mileage is calculated, the remaining drivable distance of the vehicle is calculated based on the remaining power and the average power, and the real-time distance from the electric vehicle to the next charging station is obtained through the navigation system. When the remaining drivable distance is lower than the real-time distance, the owner is prompted to switch the power mode from battery mode to extended-range mode.

[0010] As a further solution of the present invention: the calculation process of the cooling power is: Get the weights m1, m2, ..., m of the materials of different components in the power unit n , and the specific heat capacity of different component materials C1, C2, ..., C n , then the calculation formula of cooling power P is: ; Here, convert the units of v to temperature.

[0011] As a further solution of the present invention: the calculation process of the instantaneous slope is: The temperature data of the power device at multiple time points are obtained to form a temperature time series; the temperature time series is fitted to obtain a function expression about time; the current coordinate point is substituted into the function expression to obtain the instantaneous slope of the point, which is the current real-time temperature rise rate of the power device.

[0012] A power device control system for an electric vehicle, used to implement the above-mentioned power device control method for an electric vehicle, comprising: The first temperature module is used to monitor the real-time temperature of the electric vehicle power device in real time. When the real-time temperature is lower than the upper temperature limit H, the kinetic energy recovery function or the range-extending power generation function of the vehicle is controlled to be turned on; The second temperature module is used to control the vehicle thermal management system to start when the real-time temperature of the power device is higher than the upper temperature limit H, to cool the power device, and when the real-time temperature drops below H, to shut down the thermal management system and control the vehicle's kinetic energy recovery function or range-extending power generation function to start; The temperature control module is used when the vehicle charges the power device through kinetic energy recovery or extended-range power generation. During the charging process, if the real-time temperature change of the electric vehicle power device is monotonically increasing, the real-time temperature change of the power device is plotted as a power device change curve. When the real-time temperature of the power device rises to H, the current real-time temperature rise rate v of the power device is calculated according to the instantaneous slope of the current coordinate point, the heat increase rate V is calculated according to the temperature rise rate, and the cooling power P of the thermal management system is calculated according to the heat increase rate V, and the cooling power P is used as the working power of the current thermal management system.

[0013] Beneficial effects of the present invention: The present invention can accurately obtain the optimal cooling power corresponding to the power device under different environmental conditions by accurately monitoring and analyzing the real-time temperature changes of the power device, realize intelligent control of the thermal management system, improve the cooling efficiency, avoid unnecessary energy consumption, and avoid equipment damage or safety accidents caused by overheating by accurately controlling the working temperature of the power device, thereby improving the safety performance of the electric vehicle; real-time monitoring of the temperature of the power device and intelligent adjustment of the working mode can effectively reduce energy consumption, extend the battery life, thereby improving the overall energy efficiency and cruising range of the electric vehicle and enhancing the system safety; combined with the real-time distance information provided by the navigation system, it can more accurately predict the remaining drivable distance, help users to reasonably plan their trips, and avoid the inconvenience caused by insufficient power; therefore, the present invention reduces energy waste and emissions by optimizing the power device control strategy of the electric vehicle, which is conducive to environmental protection and sustainable development; due to the improved energy efficiency and cruising range, the maintenance cost is reduced, and the user can save long-term operating costs, with good economy; it provides new ideas and methods for the development of future electric vehicle technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] See also Figure 1 As shown, the present invention is a method for controlling a power device of an electric vehicle, comprising the following steps: Real-time temperature monitoring and kinetic energy recovery prompt: The system will continuously monitor the real-time temperature of the electric vehicle's power unit. When the real-time temperature is detected to be lower than the preset upper temperature limit H, the system will automatically prompt the driver to turn on the vehicle's kinetic energy recovery function or start the extended-range power generation mode at this temperature.

[0018] Thermal management system control at high temperatures: On the contrary, when the real-time temperature of the power unit exceeds the upper temperature limit H, the system will restrict the vehicle's kinetic energy recovery function or start the extended-range power generation mode, and will automatically activate the vehicle's thermal management system to cool the power unit. The thermal management system will continue to work until the temperature of the power unit drops below H, and then it will release the authority to allow the driver to start the kinetic energy recovery or extended-range power generation mode to further optimize energy utilization. Since the temperature is already below the upper temperature limit H at this time, the thermal management system is turned off. Note that H is the upper limit of the appropriate temperature, not the upper limit of the operating temperature.

[0019] Analysis of temperature changes during charging: When the temperature is lower than H, the owner can choose whether to start the energy recovery function or the extended-range power generation mode to charge the vehicle. In the process of charging the electric vehicle power unit, more heat will be generated, so the system will always monitor the temperature of the power unit. If the system detects that the temperature shows a monotonically increasing trend, it will draw this temperature change into a power unit change curve. This curve can intuitively reflect the change of temperature over time. Once the real-time temperature of the power unit rises to H, the system will calculate the real-time temperature rise rate v based on the instantaneous slope of the current coordinate point. Based on this speed, the system further calculates the heat increase rate V, and this speed V actually represents the heat accumulation rate V1 caused by charging when the temperature of the power device is H, and the speed V2 of heat exchange between the power device and the outside world at this temperature. The difference between the two, that is, V=V1-V2, because the speed of heat exchange is determined by the difference between the internal temperature of the power device and the external ambient temperature. Therefore, when the internal temperature of the power device is at different temperatures, the heat exchange rate is also different. Therefore, it is impossible to directly obtain the heat increase rate of the power device at any temperature by calculation. It can only be obtained by drawing a real-time curve and obtaining the temperature rise rate v when the temperature curve passes through H without interference from the thermal management system, and the heat increase rate V is calculated by the formula, and the cooling power P required by the thermal management system under the current environment is determined according to the heat increase rate V. The heat removal rate of the thermal management system under the cooling power can be exactly equal to the heat increase rate, so the optimal energy efficiency ratio can be achieved, and the temperature of the power device can be cooled without increasing additional power consumption.

[0020] In a preferred embodiment of the present invention, the power device includes an electric drive system, an energy storage system, a power electronic conversion system and a vehicle control system.

[0021] In a preferred embodiment of the present invention: 1. Temperature sensor deployment: High-precision temperature sensors are installed inside the battery pack of electric vehicles to monitor the temperature of the battery in real time. These sensors can provide accurate temperature readings to ensure the reliability of the data.

[0022] 2. Data collection and processing: The system will regularly collect battery temperature data and record the vehicle's mileage at each collection. By comparing the data collected twice, the system can calculate the average increase in battery temperature per unit mileage.

[0023] 3. Average temperature calculation: Using statistical methods, the temperature increase per unit mileage over a period of time is averaged to obtain a relatively stable average temperature growth index, which reflects the temperature change trend of the battery under different working conditions.

[0024] 4. Remaining distance prediction: Based on the current battery temperature and the calculated average temperature growth index, the system can predict the remaining driving distance required for the battery temperature to reach the preset upper temperature limit H. This prediction process takes into account multiple factors, such as vehicle speed, ambient temperature, battery usage status, etc.

[0025] 5.Threshold determination: When the predicted remaining distance falls below a preset threshold, the system automatically triggers an alarm mechanism. This threshold is set based on the characteristics and safety requirements of the battery to ensure that the battery is not damaged by overheating.

[0026] 6. Power mode switching prompt: Once the alarm is triggered, the system will immediately prompt the owner to switch the power mode from battery mode to extended range mode. This conversion can be achieved through an indicator light on the instrument panel or a text message on the in-vehicle infotainment system.

[0027] In a preferred embodiment of the present invention: 1. Battery remaining power monitoring: The system monitors the remaining power (SOC, State of Charge) of the electric vehicle battery in real time through high-precision sensors. These sensors can provide accurate power readings to ensure data reliability.

[0028] The monitoring data is updated regularly and transmitted to the central processing unit via the vehicle network for further analysis.

[0029] 2. Calculation of power consumption per unit mileage: The system records the average power consumed per unit mileage during each trip. This data can be dynamically adjusted based on historical driving records and current driving data to improve the accuracy of the prediction.

[0030] For example, if the vehicle is driving on a highway, the power consumption per mile may be higher than that on a city road. The system will automatically adjust the calculation model according to different road conditions and driving habits.

[0031] 3. Prediction of remaining drivable distance: Based on the current remaining battery power and the calculated average power consumption per unit mileage, the system can predict how far the vehicle can travel with the current power. This prediction process takes into account a variety of factors, such as vehicle speed, ambient temperature, battery aging, etc.

[0032] The prediction results will be displayed in real time on the dashboard or on the screen of the in-vehicle infotainment system for the driver's reference.

[0033] 4. Real-time route acquisition: The system obtains the real-time distance of the electric vehicle to the next charging station through the built-in navigation system. The navigation system can update the vehicle's location and the distance to the destination in real time based on GPS positioning and map data.

[0034] If the navigation system detects multiple available charging stations, it selects the most suitable one based on current charge level and driving speed and displays its location and estimated time of arrival.

[0035] 5. Comparison and judgment: The system compares the predicted remaining drivable distance with the distance to the next charging station acquired in real time. If the remaining drivable distance is lower than the distance to the charging station, an alarm mechanism is triggered.

[0036] The warning can be implemented through an indicator light on the instrument panel, an audible prompt or a text message on the vehicle's infotainment system, alerting the driver to the low battery condition.

[0037] 6. Power mode switching prompt: Once the alarm is triggered, the system will immediately prompt the owner to switch the power mode from battery mode to extended range mode. This conversion can be achieved through an indicator light on the instrument panel or a text message on the in-vehicle infotainment system.

[0038] In extended range mode, the vehicle will enable an auxiliary power source (such as a fuel engine or fuel cell) to reduce the burden on the battery while maintaining normal driving of the vehicle. This mode not only helps protect the battery, but also increases the vehicle's endurance.

[0039] In a preferred embodiment of the present invention, the calculation process of the cooling power is: Get the weights m1, m2, ..., m of the materials of different components in the power unit n , and the specific heat capacity of different component materials C1, C2, ..., C n , then the calculation formula of cooling power P is: ; Here, convert the units of v to temperature.

[0040] In a preferred embodiment of the present invention, the calculation process of the instantaneous slope is: The temperature data of the power device at multiple time points are obtained to form a temperature time series; the temperature time series is fitted to obtain a function expression about time; the current coordinate point is substituted into the function expression to obtain the instantaneous slope of the point, which is the current real-time temperature rise rate of the power device.

[0041] The present invention also includes a power device control system for an electric vehicle, which is used to implement the above-mentioned power device control method for an electric vehicle, comprising: The first temperature module is used to monitor the real-time temperature of the electric vehicle power device in real time. When the real-time temperature is lower than the upper temperature limit H, the kinetic energy recovery function or the range-extending power generation function of the vehicle is controlled to be turned on; The second temperature module is used to control the vehicle thermal management system to start when the real-time temperature of the power device is higher than the upper temperature limit H, to cool the power device, and when the real-time temperature drops below H, to shut down the thermal management system and control the vehicle's kinetic energy recovery function or range-extending power generation function to start; The temperature control module is used when the vehicle charges the power device through kinetic energy recovery or extended-range power generation. During the charging process, if the real-time temperature change of the electric vehicle power device is monotonically increasing, the real-time temperature change of the power device is plotted as a power device change curve. When the real-time temperature of the power device rises to H, the current real-time temperature rise rate v of the power device is calculated according to the instantaneous slope of the current coordinate point, the heat increase rate V is calculated according to the temperature rise rate, and the cooling power P of the thermal management system is calculated according to the heat increase rate V, and the cooling power P is used as the working power of the current thermal management system.

[0042] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for controlling a power device of an electric vehicle, characterized in that: The following steps are involved: Real-time monitoring of the real-time temperature of the electric vehicle power device, when the real-time temperature is lower than the upper temperature limit H, control to start the vehicle's kinetic energy recovery function or range-extending power generation function; When the real-time temperature of the power unit is higher than the upper temperature limit H, the vehicle thermal management system is controlled to start and cool the power unit. When the real-time temperature drops below H, the thermal management system is turned off and the vehicle's kinetic energy recovery function or range-extending power generation function is controlled to start; When the vehicle charges the power device through kinetic energy recovery or range-extending power generation, during the charging process, if the real-time temperature change of the electric vehicle power device is monotonically increasing, the real-time temperature change of the power device is plotted as a power device change curve. When the real-time temperature of the power device rises to H, the current real-time temperature rise rate v of the power device is calculated according to the instantaneous slope of the current coordinate point, the heat increase rate V is calculated according to the temperature rise rate, and the cooling power P of the thermal management system is calculated according to the heat increase rate V, and the cooling power P is used as the working power of the current thermal management system.

2. The method for controlling a power device of an electric vehicle according to claim 1, characterized in that: The power device includes an electric drive system, an energy storage system, a power electronic conversion system and a vehicle control system.

3. The method for controlling a power device of an electric vehicle according to claim 1, characterized in that: During the driving of the electric vehicle, the temperature of the vehicle battery is monitored in real time, and the average temperature per unit mileage increase is calculated. The remaining distance before the battery temperature exceeds the suitable temperature upper limit H is calculated based on the average temperature. When the remaining distance is lower than the preset threshold, the owner is prompted to switch the power mode from battery mode to extended-range mode.

4. The method for controlling a power device of an electric vehicle according to claim 1, characterized in that: During the driving of an electric vehicle, the remaining power of the electric vehicle battery is monitored in real time, and the average power consumed per unit mileage is calculated. The remaining drivable distance of the vehicle is calculated based on the remaining power and the average power, and the real-time distance between the electric vehicle and the next charging station is obtained through the navigation system. When the remaining drivable distance is lower than the real-time distance, the owner is prompted to switch the power mode from battery mode to extended-range mode.

5. The method for controlling a power device of an electric vehicle according to claim 1, characterized in that: The calculation process of the cooling power is: Get the weights m1, m2, ..., m of the materials of different components in the power unit n , and the specific heat capacity of different component materials C1, C2, ..., C n , then the calculation formula of cooling power P is: ； Here, convert the units of v to temperature.

6. The method for controlling a power device of an electric vehicle according to claim 1, characterized in that: The calculation process of the instantaneous slope is: The temperature data of the power device at multiple time points are obtained to form a temperature time series; the temperature time series is fitted to obtain a function expression about time; the current coordinate point is substituted into the function expression to obtain the instantaneous slope of the point, which is the current real-time temperature rise rate of the power device.

7. A power device control system for an electric vehicle, used to implement a power device control method for an electric vehicle as claimed in any one of claims 1 to 6, characterized in that: include: The first temperature module is used to monitor the real-time temperature of the electric vehicle power device in real time. When the real-time temperature is lower than the upper temperature limit H, the kinetic energy recovery function or the range-extending power generation function of the vehicle is controlled to be turned on; The second temperature module is used to control the vehicle thermal management system to start when the real-time temperature of the power device is higher than the upper temperature limit H, to cool the power device, and when the real-time temperature drops below H, to shut down the thermal management system and control the vehicle's kinetic energy recovery function or range-extending power generation function to start; The temperature control module is used when the vehicle charges the power device through kinetic energy recovery or extended-range power generation. During the charging process, if the real-time temperature change of the electric vehicle power device is monotonically increasing, the real-time temperature change of the power device is plotted as a power device change curve. When the real-time temperature of the power device rises to H, the current real-time temperature rise rate v of the power device is calculated according to the instantaneous slope of the current coordinate point, the heat increase rate V is calculated according to the temperature rise rate, and the cooling power P of the thermal management system is calculated according to the heat increase rate V, and the cooling power P is used as the working power of the current thermal management system.

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