Microwave-based rapid start method and system for hybrid electric vehicles in low temperatures

Abstract

This invention relates to the field of automotive powertrain technology and provides a method and system for rapid low-temperature start-up of hybrid electric vehicles based on microwave heating. The method includes the following steps: collecting multi-source data; preprocessing the multi-source data; evaluating the vehicle state based on oil temperature and estimated supercapacitor charge to obtain a state evaluation result; determining a start-up decision based on the state evaluation result using a fuzzy decision algorithm; the start-up decision includes microwave heating start-up or direct engine start-up; wherein the microwave heating start-up method involves controlling the supercapacitor to supply power to the magnetron in the microwave heating system, the magnetron generating microwaves to heat the oil, and simultaneously dynamically adjusting the magnetron's output power based on an adaptive power adjustment algorithm; when the oil temperature reaches a preset start-up temperature, the engine is started. This invention solves the problems of high energy consumption, low efficiency, and difficulty in starting hybrid electric vehicles in extremely cold environments.

Description

Technical Field

[0001] This invention belongs to the field of automotive powertrain technology, and particularly relates to a method and system for rapid low-temperature start-up of hybrid electric vehicles based on microwave heating. Background Technology

[0002] Hybrid electric vehicles (HEVs), as a type of vehicle that is efficient, low-emission, and combines fuel economy with flexible range, have been widely used and developed. However, in extremely cold environments, HEVs still face many challenges, among which the cold start problem remains a core issue restricting their reliability.

[0003] In low-temperature environments, the performance of hybrid vehicle batteries degrades significantly. Lithium-ion batteries experience increased internal resistance and slower chemical reaction rates at low temperatures, leading to reduced battery output power. This results in insufficient energy to start the engine and meet the high power demands of other vehicle systems during startup. Simultaneously, low temperatures significantly increase engine oil viscosity. Higher viscosity oil has poorer flowability, making it difficult to quickly reach all lubrication points, thus increasing frictional resistance between mechanical components during engine startup. This not only increases the load on the starter motor and prolongs starting time but may also lead to start-up failure. Furthermore, prolonged starting under high frictional resistance accelerates wear on engine components and shortens engine lifespan.

[0004] Currently, mainstream cold start methods have significant shortcomings. For example, the PTC + heat pipe heating method consumes a large amount of electrical energy and the heat transfer is relatively slow, making it impossible to bring the engine oil to the appropriate operating temperature in a short time; although the fuel heater can provide high heat, the heating process requires additional fuel, the preheating time is long, and there are also problems such as exhaust emissions; exhaust gas waste heat recovery technology is greatly affected by engine operating conditions, and in the initial stage of cold start, the exhaust gas heat is limited and cannot meet the need for rapid warm-up.

[0005] Therefore, developing an efficient and rapid low-temperature start-up method for hybrid electric vehicles has significant practical implications and promising application prospects. Summary of the Invention

[0006] The purpose of this invention is to provide a method for rapid low-temperature start-up of hybrid electric vehicles based on microwave heating, in order to solve the above-mentioned technical problems.

[0007] This invention is implemented as follows: a method for rapid low-temperature start-up of a hybrid electric vehicle based on microwave heating, comprising the following steps:

[0008] Collect multi-source data; the multi-source data includes engine oil temperature data, supercapacitor voltage and current data, and power battery data;

[0009] Preprocessing of multi-source data to determine estimated values ​​of oil temperature and supercapacitor charge;

[0010] The vehicle condition is assessed based on the estimated values ​​of engine oil temperature and supercapacitor charge, resulting in a condition assessment.

[0011] Based on the state assessment results, a startup decision is determined using a fuzzy decision algorithm; the startup decision includes microwave heating startup or direct engine startup.

[0012] The microwave heating start-up method is as follows: the supercapacitor supplies power to the magnetron in the microwave heating system, the magnetron generates microwaves to heat the engine oil, and the output power of the magnetron is dynamically adjusted based on an adaptive power adjustment algorithm; when the engine oil temperature reaches the preset start-up temperature, the engine is started.

[0013] Furthermore, methods for preprocessing multi-source data include:

[0014] Use the 3σ criterion to remove extreme outliers from multi-source data;

[0015] Noise reduction of multi-source data based on Kalman filtering algorithm.

[0016] Furthermore, methods for preprocessing multi-source data also include:

[0017] Establish the state equation for the charge of the supercapacitor;

[0018] Based on the extended Kalman filter iterative method, the state equation is linearized, and the Kalman filter algorithm is used to determine the estimated value of the supercapacitor charge.

[0019] Furthermore, the steps for assessing the vehicle's condition based on the estimated oil temperature and supercapacitor charge to obtain the condition assessment results specifically include:

[0020] Based on the threshold comparison method, the oil temperature is compared with the preset extreme cold threshold, and the oil temperature evaluation result is output.

[0021] Based on the threshold comparison method, the estimated supercapacitor charge is compared with the preset minimum guaranteed charge, and the supercapacitor evaluation result is output.

[0022] Furthermore, based on the state assessment results, in the step of determining the start-up decision using the fuzzy decision algorithm, when the engine oil temperature is less than the preset extreme cold threshold and the estimated supercapacitor charge is not less than the preset minimum guaranteed charge, the start-up decision is determined to be microwave heating start-up.

[0023] Furthermore, the adaptive power adjustment algorithm calculates the target power based on temperature deviation and temperature rise rate, and dynamically adjusts the magnetron output power by adjusting the duty cycle through the PWM drive circuit.

[0024] Furthermore, the power battery data includes the power battery's state of charge (SOC); the supercapacitor's power management strategy is executed based on the supercapacitor's estimated power level, and the power management strategy includes:

[0025] When the estimated supercapacitor charge is less than the preset minimum guaranteed charge: if the power battery SOC is greater than or equal to the preset first threshold, the first priority charging mode is activated to charge the supercapacitor through the DC / DC module; if the power battery SOC is less than the preset first threshold, the third priority charging mode is activated to generate electricity through the motor driven by the engine and charge the supercapacitor.

[0026] When the estimated supercapacitor charge is greater than or equal to the preset minimum guaranteed charge and less than the preset stop charging threshold, the second priority charging mode is activated first to charge the supercapacitor through regenerative braking.

[0027] When the estimated charge of the supercapacitor is greater than or equal to the preset stop charging threshold, charging of the supercapacitor is stopped.

[0028] Another objective of this invention is to provide a low-temperature rapid start system for hybrid electric vehicles based on microwave heating, used to implement the aforementioned low-temperature rapid start method for hybrid electric vehicles based on microwave heating. The system includes a supercapacitor energy storage system, a microwave heating system, and an intelligent control system. The supercapacitor energy storage system includes a supercapacitor. The microwave heating system includes a magnetron for generating microwaves and a resin-based composite oil pan with an embedded waveguide structure. The intelligent control system includes:

[0029] The data acquisition module is used to collect multi-source data, including engine oil temperature data, supercapacitor voltage and current data, and power battery data.

[0030] The data preprocessing module is used to preprocess multi-source data to determine the estimated values ​​of oil temperature and supercapacitor charge.

[0031] The condition assessment module is used to assess the vehicle condition based on the estimated oil temperature and supercapacitor charge, and obtain the condition assessment result.

[0032] The startup decision determination module is used to determine the startup decision based on the state assessment results and a fuzzy decision algorithm; the startup decision includes microwave heating startup or direct engine startup;

[0033] The microwave heating start-up method is as follows: the supercapacitor supplies power to the magnetron in the microwave heating system, the magnetron generates microwaves to heat the engine oil, and the output power of the magnetron is dynamically adjusted based on an adaptive power adjustment algorithm; when the engine oil temperature reaches the preset start-up temperature, the engine is started.

[0034] Furthermore, the supercapacitor energy storage system also includes a rectifier module, a DC / DC module, and a capacitor management unit; the rectifier module is a unidirectional power conversion unit connecting the supercapacitor and the motor; the DC / DC module is a unidirectional power conversion unit connecting the supercapacitor and the power battery; the capacitor management unit includes overcurrent protection to prevent the current flowing through the supercapacitor from exceeding the maximum allowable value and to prevent short-circuit faults, and overvoltage protection to prevent the voltage of the supercapacitor from exceeding the maximum rated voltage.

[0035] Furthermore, the microwave heating system also includes a heat dissipation module; the resin-based composite oil pan is made of glass fiber reinforced resin-based composite material, and its embedded waveguide structure has an input end connected to the magnetron; the heat dissipation module includes a fan, an air duct, and a temperature sensing unit; the fan is located on one side of the magnetron; the air duct is tightly bonded to the magnetron through a thermally conductive material; the intelligent control system also includes a PWM drive circuit, which is used to adjust the output power of the magnetron based on an adaptive power adjustment algorithm.

[0036] The present invention provides a method for rapid cold start of hybrid electric vehicles based on microwave heating, which solves the problems of high energy consumption, low efficiency and difficulty in starting hybrid electric vehicles in extremely cold environments. Specifically, it achieves rapid temperature rise by directly and uniformly heating the oil in the oil pan with microwaves, and uses the good discharge performance of supercapacitors at low temperatures to provide transient large current to the magnetron in the microwave heating system, thereby realizing rapid and reliable starting of hybrid electric vehicles in low-temperature environments. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a microwave-heated hybrid vehicle low-temperature rapid start system provided in an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the overall structure of the microwave heating system provided in an embodiment of the present invention.

[0039] Figure 3 This is a schematic diagram of the main view structure of the microwave heating system provided in an embodiment of the present invention.

[0040] Figure 4 This is a side view structural diagram of the microwave heating system provided in an embodiment of the present invention.

[0041] Figure 5 This is a top-view structural diagram of the microwave heating system provided in an embodiment of the present invention.

[0042] Figure 6 This is a flowchart illustrating the power management strategy for a supercapacitor provided in an embodiment of the present invention.

[0043] In the diagram, 1-engine; 2-clutch; 3-motor; 4-transmission; 5-braking system; 6-rectifier module; 7-power battery; 8-supercapacitor; 9-DC / DC module; 11-overcurrent protection; 12-overvoltage protection; 13-microwave heating system; 14-supercapacitor energy storage system; 15-oil pan; 16-air duct; 17-waveguide structure; 18-magnetron; 19-power input terminal; 20-air duct opening; 21-fan. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0045] like Figure 1 As shown, in one embodiment of the present invention, a low-temperature rapid start system for hybrid electric vehicles based on microwave heating is provided. This system includes a supercapacitor energy storage system 14, a microwave heating system 13, and an intelligent control system. Each system is coupled with the vehicle's existing powertrain system, using a new energy management scheme to achieve higher energy utilization efficiency and greater energy conservation and environmental friendliness in hybrid electric vehicles. It also solves problems such as increased engine oil viscosity and battery performance degradation leading to starting difficulties in low-temperature environments. The vehicle's existing powertrain system includes an engine 1, a clutch 2, a motor 3, a transmission 4, a braking system 5, a rectifier module 6, and a power battery 7.

[0046] like Figure 1 As shown, in a preferred embodiment of the present invention, the supercapacitor energy storage system 14 includes a supercapacitor 8, a rectifier module 6, a DC / DC module 9, and a capacitor management unit; the rectifier module 6 is a unidirectional power conversion unit connecting the supercapacitor 8 and the motor 3; the DC / DC module 9 is a unidirectional power conversion unit connecting the supercapacitor 8 and the power battery 7; the capacitor management unit includes overcurrent protection 11 for preventing the current flowing through the supercapacitor 8 from exceeding the maximum allowable value and preventing short circuit faults, and overvoltage protection 12 for preventing the voltage of the supercapacitor 8 from exceeding the maximum rated voltage.

[0047] Specifically, in this embodiment of the invention, a supercapacitor 8 is used as the energy storage element. The supercapacitor 8 can be designed with "50-100 supercapacitor cells connected in series + 2-3 sets of sub-modules connected in parallel", preferably with "80 supercapacitor cells connected in series + 2 sets of sub-modules connected in parallel". The voltage of each supercapacitor cell is 2.7V. The supercapacitor 8 retains more than 80% of its capacity in an environment of -40℃ (e.g., using commercially available 2.7V / 3000F supercapacitors), ensuring normal operation in cold weather. The specific number of supercapacitors 8 connected in series is determined by the matching voltage of the magnetron 18, without occupying too much space inside the car or requiring a boost module, thus reducing energy loss at low temperatures. The supercapacitor module 8 can provide a large instantaneous current (over 100A). If two supercapacitor cells are connected in parallel, the total parameters are 216V / 75F, and the instantaneous discharge current can reach 120A. It has advantages such as fast response, high power density, fast charging and discharging, and extended battery life. Furthermore, by using a scheme of connecting 2-3 sub-modules in parallel, the total energy is increased by 1-2 times, which can support at least ten low-temperature start-up heating cycles of the microwave heating system 13. This avoids the problem of the microwave heating system 13 completely losing power and the vehicle being unable to complete low-temperature start-up when a single series module fails. The supercapacitor 8 is connected in series with overcurrent protection 11 and overvoltage protection 12. Engine 1 uses a gasoline engine, but diesel engines or other internal combustion engines can also be used.

[0048] The capacitor management unit may also include a fault detection module to monitor the voltage and current status of the sub-modules in real time. When a fault is detected in one of the sub-modules (voltage deviation > 10% or current 0), the circuit of the faulty sub-module is automatically cut off, and the microwave heating system 13 is powered only through the normal sub-modules, ensuring the reliability of the low-temperature start-up function. Furthermore, the voltage fluctuation is low after 2-3 sets of supercapacitor 8 sub-modules are connected in parallel, avoiding uneven oil heating caused by voltage fluctuations and solving the technical problem of "insufficient energy for multiple starts in extremely cold environments".

[0049] The rectifier module 6 is a unidirectional power conversion unit that connects the supercapacitor 8 and the motor 3. Its function is to convert the AC power generated by the motor under the conditions of "braking energy regeneration" and "engine 1 driving the motor to generate electricity" into DC power that can charge the supercapacitor 8 module. It only allows power to flow from the motor to the supercapacitor 8 (prohibits the supercapacitor 8 from supplying power to the motor 3 in reverse).

[0050] DC / DC module 9 is a unidirectional power conversion unit that connects supercapacitor 8 and power battery 7. Its function is to charge supercapacitor 8 through DC / DC module 9 when engine 1 is off or supercapacitor 8 has low power (<20%) and needs emergency power replenishment. It also allows power to flow from power battery 7 to supercapacitor 8 only (to prevent supercapacitor 8 from charging power battery 7 in reverse, which would cause damage to power battery 7 due to the extremely large discharge current).

[0051] The components are connected as follows: the power battery 7 is connected to the supercapacitor energy storage system 14 via the DC / DC module 9. The supercapacitor energy storage system 14 supplies power to the microwave heating system 13. The engine 1 drives the drive shaft to rotate via the clutch 2. The drive shaft is connected to the rotor of the motor 3. When the vehicle brakes, the braking system 5 drives the motor 3 to generate electricity, which charges the supercapacitor 8 via the rectifier module 6.

[0052] like Figures 2-5 As shown, in a preferred embodiment of the present invention, the microwave heating system 13 includes a magnetron 18 for generating microwaves, a heat dissipation module, and an oil pan 15; wherein, the power input terminal 19 of the microwave heating system 13 can provide energy to the magnetron 18; the oil pan 15 is embedded with a waveguide structure 17, and the input terminal of the waveguide structure 17 extends to the outside of the oil pan 15 and connects to the magnetron 18; the heat dissipation module includes a fan 21, an air duct 16, and a temperature sensing unit; the fan 21 is disposed on one side of the magnetron 18; the air duct 16 is tightly attached to the magnetron 18 by a thermally conductive material.

[0053] Specifically, the magnetron 18 can generate microwaves with a frequency of 2.45 GHz. On the one hand, microwaves of this frequency have suitable penetration and absorption rates for engine oil, and can achieve uniform overall heating of engine oil in a short time through "volume heating" to avoid local overheating. On the other hand, the magnetron technology of this frequency is mature, low in cost, and the microwave heating system is easy to integrate and small in size, without occupying too much space in the engine compartment.

[0054] Fan 21 can be an axial fan, fixed to the side of magnetron 18 by rubber shock-absorbing pads. The temperature sensing unit is installed close to the magnetron 18 housing. The air duct 16 is formed using aluminum alloy technology, and the air duct opening 20 of the air duct 16 is tightly bonded to the magnetron 18 with thermal grease. When the magnetron 18 is working, the heat generated by itself is conducted to the air duct 16 through the anode. Fan 21 draws in cool air, and the airflow undergoes forced convection heat exchange with the heat dissipation channel through the air duct 16, controlling the operating temperature of the magnetron 18 within a reasonable range and preventing damage to the magnetron 18 due to overheating. The PWM drive circuit is integrated into the intelligent control system, supporting 0-100% duty cycle adjustment. The PWM drive circuit adjusts the output power of the magnetron 18 to reduce ineffective energy consumption and achieve dynamic thermal management based on data collected by sensors such as the temperature sensing unit.

[0055] Furthermore, to avoid the reflection and shielding effects of metal materials on microwave-heated oil, this embodiment of the invention uses a glass fiber reinforced resin-based composite material as the material for the oil pan 15, with an embedded waveguide structure 17. A direct microwave penetration design is employed to ensure that the microwave energy generated by the magnetron 18 directly penetrates the resin-based composite material and acts on the oil through the energy concentration of the waveguide structure 17. This material of the oil pan 15 has excellent microwave permeability, allowing the microwave energy generated by the magnetron 18 to directly penetrate the oil pan 15 and act on the oil without additional components. A temperature sensing unit can also be installed on the inner wall of the oil pan 15, 3-5 mm below the oil level, to directly monitor the real-time temperature of the oil inside the oil pan 15, providing feedback on the oil heating rate and providing a basis for the intelligent control system to determine whether heating is necessary. It should be noted that the production process of glass fiber reinforced resin matrix composites has been successfully applied in the industry. For example, high pressure resin transfer molding (HP-RTM), resin transfer molding (RTM), and compression molding processes can all produce composite materials that are compatible with the oil pan 15 of this invention. This material can be purchased from mainstream suppliers in the domestic automotive composite materials field to ensure that the microwave transmittance of the material is ≥90% to meet the core functional requirements of microwave penetration for heating engine oil.

[0056] Because automobiles experience continuous vibrations during operation and experience large impact loads from rapid acceleration / braking, to prevent the gap between the magnetron 18 and the waveguide structure 17 from widening due to vibration, which could lead to a decrease in microwave transmission efficiency or even structural loosening, this invention proposes a connection method using flange sealing and screw fastening, as detailed below:

[0057] The input flange of waveguide structure 17 has a machined sealing groove and an internal rubber gasket. The flange, through the combination of the sealing groove and the rubber gasket, forms an annular sealed space, reducing electromagnetic compatibility (EMC) issues. The output flange of magnetron 18 is matched and fastened diagonally to the flange of waveguide structure 17 using four sets of high-temperature resistant stainless steel screws (nickel-plated). Spring washers are placed around the screw holes to compensate for preload loss caused by temperature cycling. A stepped corrugated structure is designed inside waveguide structure 17 near the magnetron 18 interface. Impedance matching reduces microwave reflection. The combination of flange sealing and stepped waveguide design achieves efficient energy transmission and low leakage at the interface between magnetron 18 and waveguide structure 17, meeting the EMC requirements of automotive electronic equipment. Oil leakage and condensation may occur around the oil pan 15. The silicone-based grease in the flange sealing groove forms a waterproof and oil-proof barrier, preventing oil contamination from entering the waveguide and causing microwave transmission attenuation; it also prevents moisture from corroding the output of magnetron 18, extending the life of core components. This assembly structure is simple, reliable, safe, and easy to maintain. When the magnetron 18 is damaged, it can be easily replaced with a simple operation.

[0058] In practical applications, the magnetron 18 is fixed at the center of the outside of the oil pan 15, forming a uniform electromagnetic field within the oil pan 15 to prevent localized overheating and ensure uniform heating of the engine oil. The waveguide structure 17 is first positioned and embedded into the molding cavity of the oil pan 15 using a mold. During the molding process of the resin-based composite material, a mechanical interlocking fixation is formed. An annular groove is provided on the outer wall of the embedded section of the waveguide structure 17, filled with a high-temperature resistant structural adhesive (such as epoxy resin) to compensate for the difference in thermal expansion coefficients between the resin-based composite material and the metal. The input end of the transmission path of the waveguide structure 17 extends to the outside of the oil pan 15 to connect to the magnetron 18, and the output end opening is located in the middle of the engine oil area inside the oil pan 15.

[0059] In this embodiment of the invention, the path constraint and energy focusing structure of the waveguide structure 17 ensure that microwaves only act on the oil area and do not diffuse to other components. The oil cavity inside the oil pan 15 is separated from the external cavity by a sealing partition, preventing microwaves from penetrating the partition to enter other areas. The microwave penetration of the glass fiber reinforced resin composite material only affects a local area at the output end of the waveguide structure 17, rather than the entire shell being transparent. The area of ​​the oil pan 15 not covered by the waveguide structure 17 will not generate a heating effect due to the lack of microwave energy input, thus preventing energy from diffusing to electronic components outside the shell. The waveguide structure 17 and the magnetron 18 shell are connected to the vehicle body grounding electrode through an independent grounding wire to prevent microwave interference from being conducted to other electronic systems through a common ground path. The power supply line of the magnetron 18 (connected to the supercapacitor 8) is connected in series with an EMC filter to suppress conducted interference generated when the magnetron 18 is working, preventing interference from affecting the supercapacitor energy storage system 14 and other vehicle electrical appliances through the power line.

[0060] In a preferred embodiment of the present invention, the intelligent control system includes:

[0061] The data acquisition module is used to collect multi-source data, including engine oil temperature data, supercapacitor voltage and current data, and power battery data.

[0062] The data preprocessing module is used to preprocess multi-source data to determine the estimated values ​​of oil temperature and supercapacitor charge.

[0063] The condition assessment module is used to assess the vehicle condition based on the estimated oil temperature and supercapacitor charge, and obtain the condition assessment result.

[0064] The startup decision determination module is used to determine the startup decision based on the state assessment results and a fuzzy decision algorithm; the startup decision includes microwave heating startup or direct engine startup;

[0065] The PWM drive circuit is used to adjust the output power of the magnetron 18 based on an adaptive power regulation algorithm.

[0066] In this embodiment of the invention, all key data requiring interaction in the intelligent control system is transmitted via the CAN bus, eliminating the need for separate wiring. For example, temperature sensors (engine oil, supercapacitor, magnetron) send the collected temperature data to the intelligent control system via the CAN bus, and the intelligent control system adjusts the power of the magnetron 18 based on the data. The voltage and current of the supercapacitor 8, the SOC of the power battery, and other data are sent to the intelligent control system via the CAN bus, and the intelligent control system comprehensively judges the energy status of the entire vehicle. This intelligent control system integrates with the existing CAN network of hybrid vehicles, ensuring that new components can communicate directly with the original control system without modifying the original vehicle control logic, thus reducing the development difficulty and adaptation cost of the solution.

[0067] In another embodiment of the present invention, a method for rapid low-temperature start-up of a hybrid electric vehicle using the above-described system is also provided, specifically including the following steps:

[0068] S1. Collect multi-source data; the multi-source data includes engine oil temperature data, supercapacitor voltage and current data, and power battery data;

[0069] S2. Preprocess the multi-source data to determine the estimated values ​​of oil temperature and supercapacitor charge.

[0070] S3. Evaluate the vehicle condition based on the estimated oil temperature and supercapacitor charge to obtain the condition evaluation result;

[0071] S4. Based on the state assessment results, determine the start-up decision using a fuzzy decision algorithm; the start-up decision includes microwave heating start-up or direct start-up of engine 1;

[0072] The microwave heating start-up method is as follows: the supercapacitor 8 supplies power to the magnetron 18 in the microwave heating system 13, the magnetron 18 generates microwaves to heat the engine oil, and the output power of the magnetron 18 is dynamically adjusted based on the adaptive power adjustment algorithm; when the engine oil temperature reaches the preset start-up temperature, the engine 1 is started.

[0073] In practical applications, data acquisition and preprocessing are performed before the start command: When the driver triggers the vehicle start command, the intelligent control system (ECU) initializes the hardware status of the microwave heating system 13 and the supercapacitor energy storage system 14 (magnetron 18 in standby mode, capacitor management unit awakened), and simultaneously initializes the algorithm parameters. Core data is collected through sensors, specifically including: engine oil temperature data and supercapacitor data (sub-module voltage U). c Discharge current I c Module temperature T c ), power battery data (SOC value, output voltage U) bDuring the data acquisition process, data such as vehicle status data are collected, and Kalman filtering algorithm is used to reduce noise and eliminate sensor jitter interference.

[0074] In a preferred embodiment of the present invention, a method for preprocessing multi-source data includes:

[0075] Use the 3σ criterion to remove extreme outliers from multi-source data;

[0076] Denoising of multi-source data based on Kalman filtering algorithm;

[0077] Establish the state equation for the charge of the supercapacitor;

[0078] Based on the extended Kalman filter (EKF) iterative method, the state equation is linearized, and the Kalman filter algorithm is used to determine the estimated value of the supercapacitor charge.

[0079] Specifically, extreme outlier data (such as over-range values ​​caused by sensor failure) is eliminated by using the 3σ criterion: if data x satisfies |x-μ|>3σ, it is determined to be an outlier and replaced with the noise-reduced value from the previous moment (μ is the data mean, σ is the standard deviation, calculated based on data from the last 5 seconds).

[0080] The Extended Kalman Filter (EKF) iterative method is as follows: It utilizes the EKF algorithm to solve the nonlinear estimation problem of the supercapacitor's state of charge (SOC). The state equation (nonlinear model of supercapacitor SOC) is as follows:

[0081] ;

[0082] Among them, SOC k The supercapacitor charge at time k; SOC k-1 I represents the charge of the supercapacitor at time k-1; c,k Let be the module discharge current at time k; η is the charge / discharge efficiency, taken as 0.95 during discharge; C eq (T c The capacitance is denoted as Δt, which varies with temperature; the sampling interval is Δt. The observation equation is as follows:

[0083] ;

[0084] Among them, U c,k U is the module voltage at time k; oc (SOC k ) represents the open-circuit voltage, R eq (T c () is the equivalent resistance, which varies with temperature.

[0085] EKF iteration: The state equation is linearized, and subsequent steps utilize the Kalman filter algorithm to ultimately output the estimated state of charge (SOC) of the supercapacitor.est,k .

[0086] In a preferred embodiment of the present invention, the step of assessing the vehicle condition based on the estimated oil temperature and supercapacitor charge to obtain the condition assessment result specifically includes:

[0087] Based on the threshold comparison method, the oil temperature is compared with the preset extreme cold threshold, and the oil temperature evaluation result is output.

[0088] Based on the threshold comparison method, the estimated supercapacitor charge is compared with the preset minimum guaranteed charge, and the supercapacitor evaluation result is output.

[0089] Specifically, the extreme cold threshold can be set to -10℃, and the minimum guaranteed battery power can be set to 20%, but it is not limited to these; the threshold comparison algorithm is used to determine the oil temperature T after noise reduction preprocessing. oil Compared to the extreme cold threshold (-10℃) and the suitable start-up temperature (40℃), it can be divided into "requiring heating" (T oil <-10℃), "Startable" (40℃≤T) oil ≤60℃), "Heating in progress" (-10℃≤T) oil Three states: ≤40℃.

[0090] In addition, the evaluation results of the supercapacitor are as follows:

[0091] Minimum guaranteed charge (estimated supercapacitor charge ≥ 20%): The minimum charge that the supercapacitor 8 must always maintain ensures that it can support one complete oil heating cycle even in extreme environments such as -40℃.

[0092] Ideal starting power range (80% ≥ estimated supercapacitor power ≥ 20%): The power stored in supercapacitor 8 can support 2-3 or more low-temperature start-up heating cycles, which can cope with the scenario where the engine fails to start for the first time and requires secondary heating; at the same time, supercapacitor 8 has the longest charge-discharge cycle life under this power range.

[0093] Charging stop threshold (estimated supercapacitor charge ≥ 80%): The highest charge level at which charging of supercapacitor 8 should be stopped. Prolonged high charge levels in supercapacitor 8 can lead to increased electrolyte polarization and accelerated capacity decay. Setting a charging stop threshold of ≥ 80% for the supercapacitor ensures normal vehicle starting while extending the lifespan of supercapacitor 8.

[0094] In a preferred embodiment of the present invention, in the step of determining the start-up decision based on the state assessment result and the fuzzy decision algorithm, when the oil temperature is less than the preset extreme cold threshold and the estimated supercapacitor charge is not less than the preset minimum guaranteed charge, the start-up decision is determined to be microwave heating start-up.

[0095] In practical applications, when the driver issues a command to start the car, the intelligent control system collects the oil temperature and the estimated charge of the supercapacitor via the CAN bus. If the estimated charge of the supercapacitor is less than 20%, the supercapacitor 8 is quickly charged using the power energy of the vehicle's power battery 7, putting it into a fast charging state until the charge reaches the minimum guaranteed charge level for subsequent microwave heating system 13. If the oil temperature is less than -10℃ (extreme cold threshold) and the estimated charge of the supercapacitor is greater than or equal to 20% (minimum guaranteed charge level), the microwave heating and the low-temperature fast start process of the supercapacitor are automatically started. At this time, the intelligent control system sends a start signal, and the supercapacitor energy storage system 14 immediately provides a transient large current to the magnetron 18. The magnetron 18 is energized to generate microwaves, which are transmitted through the waveguide and penetrate the oil pan 15 to act on the oil, achieving uniform heating. During the heating process, the capacitor management unit monitors the status of the supercapacitor 8 sub-module in real time. If the voltage deviation of a sub-module is greater than 10% or the current is 0, the faulty sub-module is immediately cut off, and power is supplied only through the normal sub-module to ensure that the heating is not interrupted. The temperature sensing unit provides real-time feedback data and adjusts the output power of the magnetron 18 to make the oil temperature rise at a certain rate until it reaches the preset suitable starting temperature range (starting temperature range: 40-60℃, to ensure that it will not lose temperature rapidly when in contact with the low-temperature components inside the engine 1, and can still maintain good lubrication ability). Then, a stop signal is sent to the intelligent control system to reduce ineffective energy consumption.

[0096] Once the engine oil temperature reaches the appropriate starting temperature, the intelligent control system sends a signal to ignite and start engine 1. As the engine oil temperature rises and its viscosity decreases, the starting resistance of engine 1 decreases, enabling it to quickly reach the ignition speed.

[0097] During normal vehicle operation, the vehicle's intelligent control system monitors supercapacitor data and power battery data in real time, and manages the power of supercapacitor 8 through the aforementioned power management strategy.

[0098] This low-temperature start-up solution perfectly matches the start-up requirements of the magnetron 18 with the high transient current (above 100A) of the supercapacitor 8 at low temperatures, thus avoiding damage to the power battery 7 due to low-temperature discharge. The microwave heating characteristics solve the problem of localized overheating of the engine oil. Combined with the rapid energy replenishment of the supercapacitor 8, a closed loop of "heating-start-energy replenishment" can be achieved. Compared with traditional heating methods (PTC + heat pipe, fuel heater, waste heat recovery, etc.), this solution can shorten the start-up time by more than 50%.

[0099] In a preferred embodiment of the present invention, the adaptive power adjustment algorithm calculates the target power based on temperature deviation and temperature rise rate, and dynamically adjusts the output power of the magnetron by adjusting the duty cycle through the PWM drive circuit.

[0100] Specifically, based on the temperature deviation and temperature rise rate, the power is dynamically adjusted by changing the duty cycle D of the PWM drive circuit. k This enables power regulation of the magnetron 18, thus solving the problem of localized overheating or energy waste caused by "fixed power heating"; the specific physical formula is as follows:

[0101] ;

[0102] ;

[0103] Among them, P target(k) For target power; P max The maximum permissible power; P base k1 is the reference power; k1 is the temperature deviation coefficient, typically taken as 0.02℃. -1 k2 is the temperature rise rate coefficient, which is generally taken as 0.1 s / ℃; The rate of oil temperature rise can be calculated based on data from the past 5 seconds. This refers to the oil temperature change value; the output power range of magnetron 18 is as follows: (to avoid slow heating due to insufficient power) P min ≤P target(k) ≤P max (To avoid magnetron overload); P min The minimum allowable power.

[0104] like Figure 6 As shown, in a preferred embodiment of the present invention, the power battery data includes the power battery SOC; the power management strategy of the supercapacitor 8 is executed based on the estimated power capacity of the supercapacitor, and the power management strategy includes:

[0105] When the estimated supercapacitor charge is less than the preset minimum guaranteed charge (e.g., <20%, emergency charging zone): If the power battery SOC is greater than or equal to the preset first threshold (e.g., ≥20%), the first priority charging mode is activated to charge the supercapacitor 8 through the DC / DC module 9 until the estimated supercapacitor charge is ≥50%, quickly exiting the emergency state; If the power battery SOC is less than the preset first threshold (e.g., <20%), the third priority charging mode is activated to generate electricity through the motor 3 driven by the engine 1 and charge the supercapacitor 8 until the estimated supercapacitor charge is ≥20% (the engine 1 is only started briefly to quickly reach the guaranteed charge for one start, ensuring both emergency response and economy);

[0106] When the estimated supercapacitor charge is greater than or equal to the preset minimum guaranteed charge and less than the preset stop charging threshold (e.g., 20% ≤ estimated supercapacitor charge < 80%, in the normal charging zone), the second priority charging mode is activated first to charge the supercapacitor through regenerative braking. The charging current is dynamically adjusted according to the braking intensity, and the charging stops when the supercapacitor charge reaches 80%. It should be noted that if there is no regenerative braking and the power battery SOC is ≥ 20%, the first priority charging mode can be activated until the estimated supercapacitor charge is ≥ 50%.

[0107] When the estimated charge of the supercapacitor is greater than or equal to the preset stop charging threshold (e.g., ≥80%, stop charging zone), charging of the supercapacitor 8 is stopped, all charging paths are cut off, and only the power supply channel from the supercapacitor 8 to the microwave heating system 13 is retained. At this time, the supercapacitor 8 has enough charge for more than 8 low-temperature starts. Continuing to charge will increase the risk of overcharging of the supercapacitor 8. Cutting off the charging path avoids energy waste, protects the supercapacitor 8, and extends the cycle life.

[0108] In practical applications, the charging priority of supercapacitor 8 follows the principle of "rapid energy replenishment" over "energy-saving energy replenishment" and "no engine intervention" over "engine intervention." The core logic is to minimize the number of engine starts (reducing fuel consumption and exhaust emissions) while ensuring that supercapacitor 8 has enough power for 2-3 low-temperature starts. The specific priority order is as follows:

[0109] First priority charging mode: Supercapacitor 8 is charged through DC-DC module 9 (without engine intervention): HEV and PHEV power battery SOC ≥ 20% (the minimum SOC to meet the basic driving needs of the vehicle), and supercapacitor 8 has a charge of < 20% (not reaching the reserve charge for "2-3 low temperature starts"). While meeting the driving power of the vehicle, the supercapacitor 8 can be charged "on demand".

[0110] Second priority charging mode: Motor-braking energy regeneration charging (no engine intervention): Power battery SOC < 20%, supercapacitor 8 charge < 80%, vehicle is in braking state, recovering the energy of vehicle braking.

[0111] Third priority charging mode: Motor 3-Engine 1 drives power generation and charging (Engine 1 intervention): When the power battery SOC is less than 20%, the supercapacitor 8 has a charge of less than 20%, and there is no braking energy recovery, "emergency energy replenishment" is required (the motor 3 drives the engine 1 to generate electricity, ensuring that the supercapacitor 8 reaches the "safe starting charge" as soon as possible, and avoiding insufficient charge leading to starting failure).

[0112] In summary, this embodiment of the invention employs microwave direct heating of the engine oil, which can quickly heat the oil to a suitable starting temperature, reducing the viscosity of the engine oil in engine 1 under low-temperature conditions. This ensures good lubrication of engine 1 at the moment of startup, effectively reducing wear on engine mechanical parts and extending the service life of engine 1. The supercapacitor 8 provides a strong transient current to the magnetron 18, significantly shortening the startup time of hybrid vehicles in low-temperature environments. Compared to traditional starting methods, the startup time can be reduced by more than 50%.

[0113] Furthermore, the supercapacitor 8 maintains good discharge performance even at low temperatures, reliably providing a large transient current to the magnetron 18 in the microwave heating system 13, ensuring the normal operation of the microwave heating system 13 in low-temperature environments. Simultaneously, this embodiment of the invention uses a resin-based composite material (glass fiber reinforced) oil pan 15, solving the problem of metal materials hindering microwaves, allowing microwaves to effectively act on the engine oil, achieving rapid heating with high efficiency and low energy loss. Compared to traditional fuel heaters, this reduces fuel consumption and pollutant emissions. Moreover, the supercapacitor 8 can be charged through regenerative braking during normal vehicle operation, achieving efficient energy utilization and further improving the vehicle's energy efficiency.

[0114] The low-temperature rapid start system for hybrid electric vehicles provided in this invention can operate stably in extremely cold environments, improving the adaptability and reliability of hybrid vehicles in low-temperature regions. The microwave heating system 13, supercapacitor energy storage system 14, and intelligent control system can be well integrated with the original powertrain and electrical systems of the hybrid vehicle, requiring only relatively simple modifications to the vehicle and adjustments to the control strategy, without the need for large-scale alterations to the overall vehicle structure.

[0115] It should be noted that each of the above modules can be implemented as a computer program, which can run on a computer device. The computer device's memory can store the computer program that makes up each module, enabling the processor to execute each step of the above method.

[0116] It should be understood that although the steps in the flowcharts of the various embodiments of the present invention are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the various embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0117] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Furthermore, any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory.

[0118] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for low-temperature rapid start-up of a hybrid vehicle based on microwave heating, characterized by, The method comprises the following steps: Collecting multi-source data; the multi-source data comprises engine oil temperature data, super capacitor voltage and current data, and power battery SOC data; Preprocessing the multi-source data to determine engine oil temperature and super capacitor power estimation values; Evaluating the vehicle state according to the engine oil temperature and super capacitor power estimation values to obtain a state evaluation result; Determining a start decision based on a fuzzy decision algorithm according to the state evaluation result; the start decision comprises microwave heating start or direct start of the engine; The method of microwave heating start is to control the super capacitor to supply power to the magnetron in the microwave heating system, the magnetron generates microwaves to heat the engine oil, and the output power of the magnetron is dynamically adjusted based on an adaptive power adjustment algorithm; when the engine oil temperature reaches a preset start temperature, the engine is started; The power battery data comprises power battery SOC; the power management strategy of the super capacitor is executed based on the super capacitor power estimation value, and the power management strategy comprises: When the super capacitor power estimation value is less than a preset minimum guarantee power, if the power battery SOC is greater than or equal to a preset first threshold, a first priority charging mode is started to charge the super capacitor through the DC / DC module; if the power battery SOC is less than the preset first threshold, a third priority charging mode is started to charge the super capacitor by generating electricity through the motor driven by the engine; When the super capacitor power estimation value is greater than or equal to the preset minimum guarantee power and less than a preset stop charging threshold, a second priority charging mode is started to charge the super capacitor through brake energy regeneration; When the super capacitor power estimation value is greater than or equal to the preset stop charging threshold, the charging of the super capacitor is stopped.

2. The microwave heating based hybrid vehicle low temperature fast start method of claim 1, wherein, The method for preprocessing the multi-source data comprises: Extreme abnormal data in the multi-source data is removed by using the 3σ criterion; The multi-source data is denoised based on the Kalman filtering algorithm.

3. The microwave heating based hybrid vehicle low temperature fast start method of claim 2, wherein, The method for preprocessing the multi-source data further comprises: A state equation of the super capacitor power is established; The state equation is linearized based on the extended Kalman filter iteration method, the Kalman filtering algorithm is used to determine the estimation value of the super capacitor power.

4. The microwave heating based hybrid vehicle low temperature fast start method of claim 1, wherein, The step of evaluating the vehicle state according to the engine oil temperature and the super capacitor power estimation value to obtain a state evaluation result specifically comprises: The engine oil temperature is compared with a preset extreme cold threshold based on the threshold comparison method to output an engine oil temperature evaluation result; The super capacitor power estimation value is compared with a preset minimum guarantee power based on the threshold comparison method to output a super capacitor evaluation result.

5. The microwave heating based hybrid vehicle low temperature fast start method of claim 4, wherein, In the step of determining a start decision based on a fuzzy decision algorithm according to the state evaluation result, when the engine oil temperature is less than the preset extreme cold threshold and the super capacitor power estimation value is not less than the preset minimum guarantee power, the start decision is determined to be microwave heating start.

6. The microwave heating based hybrid vehicle low temperature fast start method of claim 1, wherein, The adaptive power adjustment algorithm calculates the target power based on the temperature deviation and the temperature rise rate, and adjusts the duty cycle through the PWM driving circuit to realize the dynamic adjustment of the output power of the magnetron.

7. A microwave heating based hybrid electric vehicle low temperature fast start system for implementing the hybrid electric vehicle low temperature fast start method of any one of claims 1-6, characterized by, The method comprises a super capacitor energy storage system, a microwave heating system, and an intelligent control system; the super capacitor energy storage system comprises a super capacitor; The microwave heating system comprises a magnetron for generating microwaves, and a resin-based composite oil sump with an embedded waveguide structure; the intelligent control system comprises: a data acquisition module for acquiring multi-source data; the multi-source data comprises engine oil temperature data, super capacitor voltage and current data, and power battery SOC data; a data preprocessing module for preprocessing the multi-source data to determine engine oil temperature and super capacitor power estimation values; a state evaluation module for evaluating the vehicle state according to the engine oil temperature and super capacitor power estimation values to obtain a state evaluation result; a start decision determination module for determining a start decision based on a fuzzy decision algorithm according to the state evaluation result; the start decision comprises microwave heating start or direct engine start. The method of microwave heating start is: controlling the super capacitor to supply power to the magnetron in the microwave heating system, the magnetron generates microwaves to heat the engine oil, and simultaneously dynamically adjusts the output power of the magnetron based on an adaptive power adjustment algorithm; when the engine oil temperature reaches a preset start temperature, the engine is started.

8. The microwave heating based hybrid vehicle low temperature fast start-up system of claim 7, wherein, The super capacitor energy storage system further comprises a rectifier module, a DC / DC module and a capacitor management unit; the rectifier module is a one-way electric energy conversion unit connecting the super capacitor and the motor; the DC / DC module is a one-way electric energy conversion unit connecting the super capacitor and the power battery; the capacitor management unit comprises an overcurrent protection for preventing the current flowing through the super capacitor from exceeding the maximum allowable value and preventing short circuit failure, and an overvoltage protection for preventing the voltage of the super capacitor from exceeding the maximum rated voltage.

9. The microwave heating based hybrid vehicle low temperature fast start-up system of claim 7, wherein, The microwave heating system further comprises a heat dissipation module; the resin-based composite oil sump is made of glass fiber reinforced resin-based composite material, and the embedded waveguide structure input end is connected to the magnetron; the heat dissipation module comprises a fan, an air duct and a temperature sensing unit; the fan is arranged on one side of the magnetron; the air duct is tightly attached to the magnetron through a heat conductive material; the intelligent control system further comprises a PWM drive circuit, which is used to adjust the output power of the magnetron based on the adaptive power adjustment algorithm.

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