Vehicle thermal management system control method and device

Abstract

The embodiment of the invention provides a vehicle thermal management system control method and device. The method comprises the steps of judging whether a battery side needs refrigeration to obtain a first judgment result; whether the passenger compartment side needs refrigeration is judged, and a second judgment result is obtained; according to the first judgment result and the second judgment result, whether the thermal management system needs to conduct single-side and double-side refrigeration switching or not is judged; if the heat management system needs to be subjected to single-side and double-side refrigeration switching, the current operation parameters of the heat management system are obtained, the current compressor rotating speed of the heat management system and the opening degree of a battery side refrigerant valve are determined, and a compressor and the refrigerant valve of the heat management system are controlled. In this way, when the thermal management system needs to conduct single-side and double-side refrigeration switching, the current rotating speed of the compressor and the opening degree of the refrigerant valve on the battery side can be adjusted in time, and therefore stable performance can be achieved when the thermal management system conducts single-side and double-side refrigeration switching, and the comfort of customers is improved.

Description

Technical Field

[0001] This disclosure relates to the field of vehicles, and more particularly to the field of vehicle thermal management system control technology. Background Technology

[0002] With the rapid development of the new energy vehicle industry and the increasing demand for low-carbon travel, the market share of new energy vehicles is growing. Compared with traditional fuel vehicles, the thermal management of new energy vehicles introduces thermal management of electric drive and battery, which greatly increases the challenge to the stability of the thermal management control system. In summer, when users use the vehicle, the cooling needs of the battery and the customer both originate from a single compressor. The refrigerant flow is distributed through two independent evaporators and two refrigerant valves. When the customer's needs and the battery's needs are constantly switching, it means that the cooling cycle needs to constantly switch between single-evaporator and dual-evaporator cycles. Due to the large heat capacity on the battery side and the mechanical characteristics of the refrigerant valve on the passenger compartment side, it is impossible to respond in time during the switching. This can lead to a sudden increase or decrease in the superheat of the compressor inlet, which may cause fluctuations in the air outlet temperature of the passenger compartment, causing discomfort to the customer. In severe cases, it may cause the compressor to be too low or too high, resulting in system shutdown, and there is also the risk of liquid slugging in the compressor, which can accumulate over time and damage the compressor, affecting its service life.

[0003] Therefore, how to ensure that the thermal management system can maintain stable performance to improve customer comfort during the switching between single and dual cooling modes, and protect the compressor to operate within safe operating limits, has become a widespread concern in the thermal management industry. Summary of the Invention

[0004] This disclosure provides a vehicle thermal management system control method, apparatus, device, and storage medium.

[0005] According to a first aspect of this disclosure, a vehicle thermal management system control method is provided. The method includes: Obtain the vehicle battery-side temperature request, determine whether the battery side needs cooling, and obtain a first determination result; Obtain the temperature request from the vehicle's passenger compartment side, determine whether the passenger compartment side needs cooling, and obtain a second determination result; Based on the first judgment result and the second judgment result, determine whether the thermal management system needs to switch between single and dual-sided cooling; If the thermal management system needs to switch between single and dual-sided cooling, then obtain the current operating parameters of the thermal management system; Based on the current operating parameters, determine the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve; Based on the current compressor speed and the opening degree of the battery-side refrigerant valve, the compressor and refrigerant valve of the thermal management system are controlled respectively.

[0006] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein obtaining the vehicle battery-side temperature request, determining whether the battery side needs cooling, and obtaining a first determination result includes: Based on the battery-side temperature request, determine the target inlet water temperature on the battery side; Obtain the actual inlet water temperature on the battery side; Determine whether the target inlet water temperature is lower than the actual inlet water temperature; If the target inlet water temperature is lower than the actual inlet water temperature, then the battery side needs to be cooled. If the target inlet water temperature is higher than the actual inlet water temperature, then the battery side does not need cooling.

[0007] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein obtaining the vehicle passenger compartment temperature request, determining whether the passenger compartment requires cooling, and obtaining a second determination result includes: Determine the corresponding target air conditioning outlet temperature based on the temperature request from the vehicle's passenger compartment. Based on the target air conditioner outlet temperature, determine the corresponding target evaporator temperature; Obtain the actual evaporator temperature; If the target evaporator temperature is lower than the actual evaporator temperature, then the occupant compartment side needs to be refrigerated. If the target evaporator temperature is higher than the actual evaporator temperature, then the occupant compartment side does not require refrigeration.

[0008] In addition to the aspects and any possible implementations described above, a further implementation is provided in which obtaining the current operating parameters of the thermal management system includes: Obtain the battery-side coolant flow rate; Obtain the target temperature and current temperature of the battery-side coolant; Obtain the specific heat capacity of the battery-side coolant; Obtain the air flow rate entering the compressor; Obtain the target air outlet temperature of the vehicle's air conditioning system; and Obtain the current air intake temperature of the air conditioner; To obtain the specific heat capacity of air; Determining the current compressor speed of the thermal management system based on the current operating parameters includes: Calculate the temperature difference of the coolant based on the target temperature and the current temperature of the coolant; The temperature difference of the air conditioner is calculated based on the target air outlet temperature and the current air inlet temperature. The load power of the thermal management system is calculated based on the coolant flow rate, the coolant temperature difference, the coolant specific heat capacity, the air flow rate entering the compressor, the air conditioner temperature difference, and the air specific heat capacity. The current compressor speed of the thermal management system is determined based on the load power of the thermal management system.

[0009] In addition to the aspects and any possible implementations described above, a further implementation is provided in which determining the current compressor speed of the thermal management system based on the load power of the thermal management system includes: Calculate the corresponding first compressor compensation speed based on the temperature difference of the air conditioner; Obtain the current actual power of the compressor; Calculate the power difference between the load power and the current actual power; Obtain the preset coolant adjustment gain; Calculate the corresponding second compressor compensation speed based on the power difference and the preset coolant adjustment gain; The current compressor speed is calculated based on the first compressor compensation speed and the second compressor compensation speed.

[0010] In addition to the aspects and any possible implementations described above, a further implementation is provided in which obtaining the current operating parameters of the thermal management system includes: Obtain the preset characteristic parameters of the battery-side refrigerant valve; Obtain the current superheat and superheat change rate of the vehicle's air conditioning; Based on the current operating parameters, determine the opening degree of the battery-side refrigerant valve, including: Calculate the first opening degree of the refrigerant valve based on the preset characteristic parameters and the current time; Calculate the second opening degree of the refrigerant valve based on the current superheat and superheat change rate of the air conditioner; The final opening degree of the battery-side refrigerant valve is determined based on the first opening degree and the second opening degree.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein calculating the second opening degree of the refrigerant valve based on the current superheat and the superheat change rate of the air conditioner includes: Obtain the preset reference superheat of the air conditioner; The dynamic safe superheat boundary of the air conditioner is calculated based on the preset benchmark superheat, the superheat change rate, and the preset superheat change coefficient; wherein, the preset superheat change coefficient varies according to the superheat change rate. The second opening degree of the refrigerant valve is obtained by performing PID calculations based on the current superheat and the dynamic safe superheat boundary.

[0012] In addition to the aspects described above and any possible implementations, a further implementation is provided, wherein determining the final opening degree of the battery-side refrigerant valve based on the first opening degree and the second opening degree includes: Obtain the preset overheat threshold; Calculate the absolute value of the difference between the first opening degree and the second opening degree; If the absolute value of the opening difference is less than the preset overheat threshold, then the overheat dynamic adjustment weight coefficient is obtained; The final opening degree of the battery-side refrigerant valve is determined based on the superheat dynamic adjustment weighting coefficient, the first opening degree, and the second opening degree. If the absolute value of the opening difference is greater than or equal to the preset superheat threshold, then the final opening of the battery-side refrigerant valve is determined to be the second opening.

[0013] As described above and in any possible implementation, a further implementation is provided, wherein obtaining the overheating dynamic adjustment weight coefficient includes: Obtain the basic overheating weight; Obtain the preset maximum allowable rate of change of superheat; The superheat dynamic adjustment weight coefficient is calculated based on the basic superheat weight, the superheat change rate, and the preset maximum allowable superheat change rate.

[0014] According to a second aspect of this disclosure, a vehicle thermal management system control device is provided. The device includes: The first processing module is used to obtain the temperature request of the vehicle battery side, determine whether the battery side needs cooling, and obtain a first determination result. The second processing module is used to obtain the temperature request of the vehicle passenger compartment side, determine whether the passenger compartment side needs cooling, and obtain a second determination result. The judgment module is used to determine whether the thermal management system needs to switch between single and dual-sided cooling based on the first judgment result and the second judgment result. The acquisition module is used to acquire the current operating parameters of the thermal management system if the thermal management system needs to switch between single and dual-sided cooling. The determination module is used to determine the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve based on the current operating parameters. The control module is used to control the compressor and refrigerant valve of the thermal management system according to the current compressor speed and the opening degree of the battery-side refrigerant valve, respectively.

[0015] According to a third aspect of this disclosure, an electronic device is provided. The electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described above.

[0016] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the method according to a first aspect of this disclosure.

[0017] In this disclosure, after obtaining the vehicle battery-side temperature request, it can be determined whether the battery side needs cooling to obtain a first determination result. After obtaining the vehicle passenger compartment-side temperature request, it can be determined whether the passenger compartment side needs cooling to obtain a second determination result. Then, based on the first determination result and the second determination result, it can be accurately determined whether the thermal management system needs to switch between single and dual-side cooling. When the thermal management system needs to switch between single and dual-side cooling, the current operating parameters of the thermal management system can be obtained. Then, based on the current operating parameters, the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve are determined. Then, based on the current compressor speed and the opening degree of the battery-side refrigerant valve, the compressor and refrigerant valve of the thermal management system are controlled respectively. In this way, when the thermal management system needs to switch between single and dual-side cooling, the current compressor speed and the opening degree of the battery-side refrigerant valve can be adjusted in time, so that the thermal management system can maintain stable performance and improve customer comfort when switching between single and dual-side cooling, and protect the compressor from operating within a safe superheat operating boundary.

[0018] It should be understood that the description in the Summary of the Invention section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0019] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the invention and are not intended to limit the scope of this disclosure. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein: Figure 1 A flowchart of a vehicle thermal management system control method according to an embodiment of the present disclosure is shown; Figure 2 A block diagram of a vehicle thermal management system control device according to an embodiment of the present disclosure is shown; Figure 3 A block diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0021] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0022] Figure 1 A flowchart of a vehicle thermal management system control method 100 according to an embodiment of the present disclosure is shown. Method 100 may include: Step 110: Obtain the vehicle battery-side temperature request, determine whether the battery side needs cooling, and obtain a first determination result; Step 120: Obtain the temperature request on the passenger compartment side of the vehicle, determine whether the passenger compartment side needs cooling, and obtain a second determination result; Step 130: Based on the first judgment result and the second judgment result, determine whether the thermal management system needs to switch between single and dual-sided cooling. Single / dual-sided cooling switching includes: The cooling requirement has been switched from requiring cooling on the single-passenger-cabin side to requiring cooling on both the passenger-cabin and battery sides. The cooling requirement shifts from the single battery side to the passenger compartment side requiring cooling plus the battery side. The need for cooling has shifted from the passenger compartment side requiring cooling plus the battery side to the passenger compartment side requiring cooling. as well as The system switches from requiring cooling on the crew cabin side and the battery side to requiring cooling on the battery side.

[0023] It should be noted that since this application only switches between cooling and heating modes, the thermal management system can be a cooling system.

[0024] Step 140: If the thermal management system needs to switch between single and dual-sided cooling, then obtain the current operating parameters of the thermal management system. Step 150: Determine the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve based on the current operating parameters; Step 160: Control the compressor and refrigerant valve of the thermal management system according to the current compressor speed and the opening degree of the battery-side refrigerant valve.

[0025] In addition, the thermal management system has two evaporators and two refrigerant valves. Specifically, the heat exchange equipment on the battery side is called a heat exchanger, and the heat exchange equipment on the passenger compartment side is called an evaporator. Furthermore, the refrigerant valve on the battery side is called an electronic expansion valve, and the refrigerant valve on the passenger compartment side is called a thermal expansion valve. The thermal expansion valve is mechanical and has an adjustment delay. The adjustment of the refrigerant valve opening in this invention refers to adjusting the opening of the refrigerant valve on the battery side.

[0026] After obtaining the vehicle battery-side temperature request, it can be determined whether the battery side needs cooling to obtain a first determination result. After obtaining the vehicle passenger compartment-side temperature request, it can be determined whether the passenger compartment side needs cooling to obtain a second determination result. Then, based on the first determination result and the second determination result, it can be accurately determined whether the thermal management system needs to switch between single and dual-side cooling. When the thermal management system needs to switch between single and dual-side cooling, the current operating parameters of the thermal management system can be obtained. Then, based on the current operating parameters, the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve can be determined. Then, based on the current compressor speed and the opening degree of the battery-side refrigerant valve, the compressor and refrigerant valve of the thermal management system are controlled respectively. In this way, when the thermal management system needs to switch between single and dual-side cooling, the current compressor speed and the opening degree of the battery-side refrigerant valve can be adjusted in time, so that the thermal management system can maintain stable performance and improve customer comfort when switching between single and dual-side cooling, and protect the compressor from operating within a safe superheat operating boundary.

[0027] In some embodiments, obtaining the vehicle battery-side temperature request, determining whether the battery side needs cooling, and obtaining a first determination result includes: Based on the battery-side temperature request, determine the target inlet water temperature on the battery side; The battery-side temperature request originates from the battery pack.

[0028] Obtain the actual inlet water temperature on the battery side; Determine whether the target inlet water temperature is lower than the actual inlet water temperature; If the target inlet water temperature is lower than the actual inlet water temperature, then the battery side needs to be cooled. If the target inlet water temperature is higher than the actual inlet water temperature, then the battery side does not need cooling.

[0029] After determining whether the target inlet water temperature is lower than the actual inlet water temperature, if the target inlet water temperature is lower than the actual inlet water temperature, it indicates that the actual inlet water temperature on the battery side is too high and needs to be lowered to the target inlet water temperature. Therefore, it indicates that the battery side needs cooling. If the target inlet water temperature is higher than the actual inlet water temperature, it indicates that the actual inlet water temperature on the battery side is too low and needs to be raised to the target inlet water temperature. Therefore, it indicates that the battery side does not need cooling or even needs heating.

[0030] In some embodiments, obtaining the vehicle passenger compartment temperature request, determining whether the passenger compartment requires cooling, and obtaining a second determination result includes: Determine the corresponding target air conditioning outlet temperature based on the temperature request from the vehicle's passenger compartment. The temperature requested by the passenger cabin temperature request is based on the settings set by the customer using the large screen.

[0031] Based on the target air conditioner outlet temperature, determine the corresponding target evaporator temperature; The target air conditioner outlet temperature is the target temperature at the air conditioner outlet.

[0032] By obtaining the correspondence between the user-set temperature, the air conditioning outlet temperature, and the evaporator temperature, the target air conditioning outlet temperature can be accurately determined based on the temperature requested by the passenger compartment temperature request and the correspondence between these three, and thus the target evaporator temperature can be determined.

[0033] Obtain the actual evaporator temperature; If the target evaporator temperature is lower than the actual evaporator temperature, then the occupant compartment side needs to be refrigerated. If the target evaporator temperature is higher than the actual evaporator temperature, then the occupant compartment side does not require refrigeration.

[0034] After determining whether the target evaporator temperature is lower than the actual evaporator temperature, if the target evaporator temperature is lower than the actual evaporator temperature, it indicates that the actual evaporator temperature on the passenger compartment side is too high and needs to be lowered to the target evaporator temperature. Therefore, it indicates that the passenger compartment side needs cooling. If the target evaporator temperature is higher than the actual evaporator temperature, it indicates that the actual evaporator temperature on the passenger compartment side is too low and needs to be raised to the target evaporator temperature. Therefore, it indicates that the passenger compartment side does not need cooling or even needs heating.

[0035] In some embodiments, obtaining the current operating parameters of the thermal management system includes: Obtain the battery-side coolant flow rate; Coolant refers to the heat exchange medium in the battery pack cooling circuit. The battery relies on the coolant for heat exchange. After the compressor pumps the refrigerant in, the refrigerant exchanges heat with the coolant, and then the coolant exchanges heat with the battery, thereby cooling the battery.

[0036] Obtain the target temperature and current temperature of the battery-side coolant; Obtain the specific heat capacity of the battery-side coolant; Obtain the air flow rate entering the compressor; Obtain the target air outlet temperature of the vehicle's air conditioning system; and Obtain the current air intake temperature of the air conditioner; To obtain the specific heat capacity of air; Determining the current compressor speed of the thermal management system based on the current operating parameters includes: Calculate the temperature difference of the coolant based on the target temperature and the current temperature of the coolant; The temperature difference of the air conditioner is calculated based on the target air outlet temperature and the current air inlet temperature. The load power of the thermal management system is calculated based on the coolant flow rate, the coolant temperature difference, the coolant specific heat capacity, the air flow rate entering the compressor, the air conditioner temperature difference, and the air specific heat capacity. The current compressor speed of the thermal management system is determined based on the load power of the thermal management system.

[0037] By calculating the temperature difference of the coolant and the temperature difference of the air conditioner, the load power on the compressor side and the load power on the battery side of the thermal management system can be calculated based on the coolant flow rate, the temperature difference of the coolant, the specific heat capacity of the coolant, the air flow rate entering the compressor, the temperature difference of the air conditioner, and the specific heat capacity of the air. Then, by adding them together, the load power of the thermal management system can be accurately obtained.

[0038] The load power P of the thermal management system target : P target = M bat_coolant *C bat_coolant *(ΔT bat_coolant ) + M cab_air *C cab_air *(ΔT cab_air ) M bat_coolant Battery-side coolant mass flow rate (unit: kg / s) C bat_coolant Specific heat capacity of battery-side coolant (unit: kJ / (kg*℃)) ΔT bat_coolantTemperature difference (target coolant temperature - current coolant temperature, unit: °C) M cab_air Air mass flow rate (kg / s) (The air volume for the corresponding voltage setting is obtained based on the blower product parameters of the air conditioning unit). C cab_air The specific heat capacity of air is approximately taken as 1.0 kJ / (kg*℃). ΔT cab_air Temperature difference (target outlet air temperature - current inlet air temperature, unit: °C) In some embodiments, determining the current compressor speed of the thermal management system based on the load power of the thermal management system includes: Calculate the corresponding first compressor compensation speed based on the temperature difference of the air conditioner; The first compressor compensation speed can be obtained by performing PID calculations based on the temperature difference of the air conditioner.

[0039] First compressor compensation speed RPM target The calculation method is as follows: RPM target = K p *e(t)+K i * e(t)dt+K d *de(t) / dt Parameter description: e(t) = -ΔT cab_air (The compressor speed is inversely proportional to the temperature difference, so the error value is inverted relative to the temperature difference.) K p K i K d PID control parameters, calibration values; Obtain the current actual power of the compressor; Calculate the power difference between the load power and the current actual power; Obtain the preset coolant adjustment gain; Calculate the corresponding second compressor compensation speed based on the power difference and the preset coolant adjustment gain; The power difference is multiplied by the preset coolant adjustment gain to obtain the corresponding second compressor compensation speed.

[0040] The current compressor speed is calculated based on the first compressor compensation speed and the second compressor compensation speed.

[0041] Since the temperature of the air conditioner affects the cooling effect, and the change of load also affects the cooling effect, the corresponding first compressor compensation speed can be accurately calculated based on the temperature difference of the air conditioner. The corresponding second compressor compensation speed can be accurately calculated based on the power difference and the preset coolant adjustment gain. Then, based on the first compressor compensation speed and the second compressor compensation speed, the current compressor speed can be accurately calculated.

[0042] In some embodiments, obtaining the current operating parameters of the thermal management system includes: Obtain the preset characteristic parameters of the battery-side refrigerant valve; Obtain the current superheat and superheat change rate of the vehicle's air conditioning; Based on the current operating parameters, determine the opening degree of the battery-side refrigerant valve, including: Calculate the first opening degree of the refrigerant valve based on the preset characteristic parameters and the current time; The initial opening degree during the transition from single-cooling to dual-cooling (i.e., switching from single-cooling to dual-cooling). α slow as follows: α slow = 1- e t / τ τ is the preset characteristic parameter, and t is the current time. The initial opening degree during the transition from dual-cooling to single-cooling (i.e., switching from dual-cooling to single-cooling). α slow as follows: α slow = e t / τ α slow This represents the refrigerant valve opening (0 to 1 maps to 0-100%). Calculate the second opening degree of the refrigerant valve based on the current superheat and superheat change rate of the air conditioner; Second opening α pid as follows: α pid =K p *(SH-SH) target )+K i * (SH - SH) target )dt+K d *d(SH - SH) target ) / dt SH indicates current popularity. target For dynamic safety overheating boundary, SH target =Min[Max[(SH safe - K dyn *Slope SH ),-5] , 15 ],Slope SH This represents the rate of change of superheat.

[0043] The final opening degree of the battery-side refrigerant valve is determined based on the first opening degree and the second opening degree.

[0044] Based on preset characteristic parameters and the current time, the first opening degree of the refrigerant valve can be accurately calculated. Based on the current superheat and superheat change rate of the air conditioner, the second opening degree of the refrigerant valve can be accurately calculated. Furthermore, based on the first opening degree and the second opening degree, the final opening degree of the battery-side refrigerant valve can be accurately calculated, so as to accurately control the opening degree of the battery-side refrigerant valve.

[0045] In some embodiments, calculating the second opening degree of the refrigerant valve based on the current superheat and the rate of change of superheat of the air conditioner includes: Obtain the preset reference superheat of the air conditioner; The dynamic safe superheat boundary of the air conditioner is calculated based on the preset benchmark superheat, the superheat change rate, and the preset superheat change coefficient; wherein, the preset superheat change coefficient varies according to the superheat change rate. The second opening degree of the refrigerant valve is obtained by performing PID calculations based on the current superheat and the dynamic safe superheat boundary.

[0046] Based on the preset benchmark superheat, the superheat change rate, and the preset superheat change coefficient, the dynamic safe superheat boundary of the air conditioner can be calculated. Then, based on the current superheat and the dynamic safe superheat boundary, PID calculation can be performed to accurately obtain the second opening degree of the refrigerant valve. In this way, the opening degree of the refrigerant valve can be accurately calculated based on the superheat, ensuring that the superheat is always maintained within the dynamic safe superheat boundary during the refrigerant adjustment process. This avoids the situation where simply setting a fixed safe superheat boundary leads to insufficient flexibility in the adjustment of the refrigerant valve and unsatisfactory control effect.

[0047] In some embodiments, determining the final opening degree of the battery-side refrigerant valve based on the first opening degree and the second opening degree includes: Obtain the preset overheat threshold; Calculate the absolute value of the difference between the first opening degree and the second opening degree; If the absolute value of the opening difference is less than the preset overheat threshold, then the overheat dynamic adjustment weight coefficient is obtained; The final opening degree of the battery-side refrigerant valve is determined based on the superheat dynamic adjustment weighting coefficient, the first opening degree, and the second opening degree. If the absolute value of the opening difference is greater than or equal to the preset superheat threshold, then the final opening of the battery-side refrigerant valve is determined to be the second opening.

[0048] After calculating the absolute value of the opening difference between the first opening degree and the second opening degree, if the absolute value of the opening difference is less than the preset superheat threshold, it indicates that the superheat change is not too large and has not deviated much from the safety boundary. Therefore, the superheat dynamic adjustment weight coefficient can be obtained, and then combined with the superheat dynamic adjustment weight coefficient, the first opening degree, and the second opening degree, the final opening degree of the battery-side refrigerant valve can be accurately calculated. If the absolute value of the opening difference is greater than or equal to the preset superheat threshold, it indicates that the superheat change is large and has deviated much from the dynamic safety superheat boundary. The opening degree calculated by PID obviously has a faster adjustment rate. Therefore, the second opening degree obtained by PID calculation based on superheat can be directly determined as the final opening degree of the battery-side refrigerant valve so as to quickly adjust the opening degree of the refrigerant valve.

[0049] The final opening degree of the battery-side refrigerant valve is calculated as shown in Table 1 below: Table 1

[0050] The preset superheat threshold is α th The superheat dynamic adjustment weighting coefficient is K. slow The final opening is α final Second opening α pid The first opening is α slow .

[0051] In some embodiments, obtaining the dynamic adjustment weighting coefficient for overheating includes: Obtain the basic overheating weight; Obtain the preset maximum allowable rate of change of superheat; The superheat dynamic adjustment weight coefficient is calculated based on the basic superheat weight, the superheat change rate, and the preset maximum allowable superheat change rate.

[0052] After obtaining the basic superheat weight and the preset maximum allowable superheat change rate, the superheat dynamic adjustment weight coefficient can be accurately calculated based on the basic superheat weight, the superheat change rate, and the preset maximum allowable superheat change rate.

[0053] The vehicle thermal management system control method provided in this embodiment of the invention includes the following steps S1 to S3.

[0054] S1 determines whether to switch the cooling system based on the vehicle's current cooling needs.

[0055] Among them, the battery demand needs to determine whether the battery requests cooling based on the BMS (Battery Management System) request. Specifically, it is determined whether the battery-side cooling cycle needs to be turned on based on the target water inlet temperature and the actual water inlet temperature of the battery. Passenger cabin side cooling requirements: Based on the temperature set by the customer via the large screen, calculate the target air conditioning outlet temperature, then calculate the target evaporator temperature based on the target air conditioning outlet temperature, and finally determine whether it is necessary to start the passenger cabin side cooling cycle based on the actual evaporator temperature and the target evaporator temperature. The system mode requirement changes from a dual-evaporator refrigeration cycle to a single-evaporator refrigeration cycle, or from a single-evaporator refrigeration cycle to a dual-evaporator refrigeration cycle. The compressor speed and the opening of the electronic expansion valve are controlled by the S2 calculation function. S2, acquire relevant sensor information from the vehicle's thermal management system and perform control signal calculations. Compressor control algorithm (feedforward + PID) Algorithm Design: Calculate system load (feedforward) P target = M bat_coolant *C bat_coolant *(ΔT bat_coolant ) + M cab_air *C cab_air *(ΔT cab_air ) ΔP = P target - P actual P targe This is the load power of the thermal management system.

[0056] P actual (Actual power calculated based on the voltage and current feedback from the compressor, unit: kilojoules (kW)) M bat_coolant Battery-side coolant mass flow rate (unit: kg / s) C bat_coolant Specific heat capacity of battery-side coolant (unit: kJ / (kg*℃)) ΔTbat_coolant Temperature difference (target coolant temperature - current coolant temperature, unit: °C) M cab_air Air mass flow rate (kg / s) (The air volume for the corresponding voltage setting is obtained based on the blower product parameters of the air conditioning unit). C cab_air The specific heat capacity of air is approximately taken as 1.0 kJ / (kg*℃). ΔT cab_air Temperature difference (target outlet air temperature - current inlet air temperature, unit: °C) The compressor uses a feedforward + PID control method: Feedforward compensation speed (to anticipate increases or decreases in cooling capacity) RPM ff = K ff *ΔP, RPM ff That is, the second compressor compensation speed K ff Feedforward gain (calibrated value rpm / kW) K ff That is, preset coolant adjustment gain Feedback-compensated speed (PID) RPM target = K p *e(t)+K i * e(t)dt+K d *de(t) / dt RPM target That is, the first compressor compensation speed; Parameter description: e(t) = -ΔT cab_air (The compressor speed is inversely proportional to the temperature difference, so the error value is inverted relative to the temperature difference.) K p K i K d PID control parameters, calibration values; Compressor final speed control: RPM cmd = RPM ff + RPM target RPM target A speed limit of [0, maximum speed of individual compressor unit] is required; RPM cmd That is, the current compressor speed of the compressor in the thermal management system.

[0057] 2. The electronic expansion valve (battery-side electronic expansion valve) control algorithm in the industry generally adopts the combination of passenger compartment thermal expansion valve and battery-side electronic expansion valve to control the overall vehicle cost. The thermal expansion valve does not require software algorithm control and mainly achieves overheat control by controlling the battery-side electronic expansion valve. Therefore, this patent only designs the battery-side electronic expansion valve algorithm. Slow-opening strategy when switching from single-steam to dual-steam operation (electronic expansion valve opens gradually to prevent fluctuations in air conditioning outlet temperature). α slow = 1- e t / τ α slow This represents the refrigerant valve opening (0 to 1 maps to 0-100%). τ is a time constant that can be calibrated according to the characteristics of the valve; When battery cooling demand is activated, the refrigerant valve slow-opening strategy gives the system enough time to increase the compressor speed according to the air outlet temperature and evaporator temperature, preventing fluctuations in air conditioner air outlet temperature and overheating. The gradual shut-off strategy during dual-evaporation switching to single-evaporation (the electronic expansion valve gradually closes, recovering excess cooling energy into the battery cooling water). α slow = e t / τ α slow This represents the refrigerant valve opening (0 to 1 maps to 0-100%). τ is a time constant that can be calibrated according to the characteristics of the valve; that is, τ is a preset characteristic parameter. When the battery cooling demand is cancelled, the refrigerant valve slow-down strategy is implemented, and the battery water pump continues to run, continuing to recover excess cooling capacity into the battery cooling water. This gives the system sufficient time to reduce the compressor speed based on the outlet air temperature and evaporator temperature, preventing fluctuations in air conditioner outlet air temperature and overheating. α slow That is, the first opening degree of the refrigerant valve.

[0058] System superheat control strategy (monitoring superheat to prevent compressor liquid slugging and over-evaporation). Basic definition of superheat SH=T eva_out –T sat(P) Note: Current superheat SH = evaporator outlet temperature T eva_out —The saturation temperature T corresponding to the current refrigerant pressure sat(P) (The refrigerant is at the evaporator outlet. There is a temperature sensor and a pressure sensor at the evaporator outlet. The temperature sensor detects the evaporator outlet temperature, and the pressure sensor detects the refrigerant pressure as the current refrigerant pressure. The evaporator outlet is connected to the compressor inlet, and the compressor pumps the refrigerant from the evaporator outlet into the compressor.) Calculation of dynamic safe superheat boundary (based on rate of change adjustment) SH target =Min[Max[(SH safe - K dyn *Slope SH ),-5] , 15 ],K dyn To preset the superheat change coefficient, it can be based on the superheat change rate Slope. SH Dynamic adjustments are made, as shown in Table 2.

[0059] Slope of superheat change SH =[SH(t) - SH(t-Δt) ] / dt Table 2

[0060] Parameter description: SH safe Reference superheat (3°C to 5°C) K dyn The dynamic safety factor (i.e., the preset superheat variation coefficient) can be obtained by linearly looking up the data in the MapTable described above. Suggested slope calculation interval: Δt = 1s (detect the rate of change of superheat within 1 second; if K is adjusted...) dyn The MapTable also needs to be adjusted. PID formula for controlling refrigerant valve α pid =K p *(SH-SH) target )+K i * (SH - SH) target )dt+K d *d(SH - SH) target ) / dt Parameter description: K p K i K d PID control parameters, calibration values; α pid That is, the second opening.

[0061] α pidAmplitude limit required [0-100] (unit: %) System shutdown threshold (emergency shutdown, i.e., if the rate of change of superheat changes too rapidly, the compressor will be shut down immediately to prevent sudden changes). Threshold stop = |d 2 SH / d 2 t| Threshold stop Recommended threshold: 5℃ / s 2 S3 Refrigerant Valve Slow Opening and Slow Closing α slow With superheat PID control α pid Arbitration output When the PID calculated value (overheat safety boundary control) conflicts with the slow-opening and slow-closing calculated value (energy saving and comfort control), a dynamic priority arbitration mechanism is adopted to ensure the safety and control accuracy of the system. The specific solution is as follows:

[0062] Parameter description: α th The opening difference threshold is the preset overheat threshold (10% to 15% is recommended). Adjust the ramp / ramp weight K in real time according to the system status. slow : K slow =Max [ K base *(1 - |Slope SH | / Slope rate_max ), 0], K slow That is, the weighting coefficient for superheat is dynamically adjusted; K base The base weight is the base overheating weight (recommended to be 0.4 to 0.6). Sloperate_max: The maximum allowable slope of superheat, i.e., the preset maximum allowable rate of change of superheat (3℃ recommended). If the superheat changes drastically, for example: |Slope SH |>= Slope rate_max (3℃ / s), then K slow = 0, with superheat safety boundary control taking precedence; If the change is gradual, for example: |Slope SH If | = 0 ℃ / s, then K base = K slow Energy conservation and comfort control are the main focuses.

[0063] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions, because according to this disclosure, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this disclosure.

[0064] The above is an introduction to the method embodiments. The following describes the solution described in this disclosure further through device embodiments.

[0065] Figure 2 A block diagram of a vehicle thermal management system control device 200 according to an embodiment of the present disclosure is shown. Figure 2 As shown, the device 200 includes: The first processing module 210 is used to obtain the vehicle battery side temperature request, determine whether the battery side needs cooling, and obtain a first determination result. The second processing module 220 is used to obtain the temperature request of the vehicle passenger compartment side, determine whether the passenger compartment side needs cooling, and obtain a second determination result. The judgment module 230 is used to determine whether the thermal management system needs to switch between single and dual-sided cooling based on the first judgment result and the second judgment result. The acquisition module 240 is used to acquire the current operating parameters of the thermal management system if the thermal management system needs to switch between single and dual-sided cooling. The determining module 250 is used to determine the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve based on the current operating parameters. The control module 260 is used to control the compressor and refrigerant valve of the thermal management system according to the current compressor speed and the opening degree of the battery-side refrigerant valve, respectively.

[0066] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0067] According to embodiments of the present disclosure, the present disclosure also provides an electronic device and a non-transitory computer-readable storage medium storing computer instructions.

[0068] Figure 3A schematic block diagram of an electronic device 800 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0069] Device 800 includes a computing unit 801, which can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) 802 or a computer program loaded from storage unit 808 into random access memory (RAM) 803. RAM 803 may also store various programs and data required for the operation of device 800. The computing unit 801, ROM 802, and RAM 803 are interconnected via bus 804. Input / output (I / O) interface 805 is also connected to bus 804.

[0070] Multiple components in device 800 are connected to I / O interface 805, including: input unit 806, such as keyboard, mouse, etc.; output unit 807, such as various types of monitors, speakers, etc.; storage unit 808, such as disk, optical disk, etc.; and communication unit 809, such as network card, modem, wireless transceiver, etc. Communication unit 809 allows device 800 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0071] The computing unit 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 801 performs the various methods and processes described above, such as method 100. For example, in some embodiments, method 100 may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, part or all of the computer program may be loaded and / or installed on device 800 via ROM 802 and / or communication unit 809. When the computer program is loaded into RAM 803 and executed by the computing unit 801, one or more steps of method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 801 may be configured to perform method 100 by any other suitable means (e.g., by means of firmware).

[0072] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0073] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0074] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0075] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0076] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0077] Computing systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0078] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0079] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A control method for a vehicle thermal management system, characterized in that, include: Obtain the vehicle battery-side temperature request, determine whether the battery side needs cooling, and obtain a first determination result; Obtain the temperature request from the vehicle's passenger compartment side, determine whether the passenger compartment side needs cooling, and obtain a second determination result; Based on the first judgment result and the second judgment result, determine whether the thermal management system needs to switch between single and dual-sided cooling; If the thermal management system needs to switch between single and dual-sided cooling, then obtain the current operating parameters of the thermal management system; Based on the current operating parameters, determine the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve; Based on the current compressor speed and the opening degree of the battery-side refrigerant valve, the compressor and refrigerant valve of the thermal management system are controlled respectively.

2. The method as described in claim 1, characterized in that, The step of obtaining the vehicle battery-side temperature request, determining whether the battery side needs cooling, and obtaining a first determination result includes: Based on the battery-side temperature request, determine the target inlet water temperature on the battery side; Obtain the actual inlet water temperature on the battery side; Determine whether the target inlet water temperature is lower than the actual inlet water temperature; If the target inlet water temperature is lower than the actual inlet water temperature, then the battery side needs to be cooled. If the target inlet water temperature is higher than the actual inlet water temperature, then the battery side does not need cooling.

3. The method as described in claim 1, characterized in that, The process of obtaining the vehicle passenger compartment temperature request, determining whether the passenger compartment requires cooling, and obtaining a second determination result includes: Determine the corresponding target air conditioning outlet temperature based on the temperature request from the vehicle's passenger compartment. Based on the target air conditioner outlet temperature, determine the corresponding target evaporator temperature; Obtain the actual evaporator temperature; If the target evaporator temperature is lower than the actual evaporator temperature, then the occupant compartment side needs to be refrigerated. If the target evaporator temperature is higher than the actual evaporator temperature, then the occupant compartment side does not require refrigeration.

4. The method according to claim 1, characterized in that, The step of obtaining the current operating parameters of the thermal management system includes: Obtain the battery-side coolant flow rate; Obtain the target temperature and current temperature of the battery-side coolant; Obtain the specific heat capacity of the battery-side coolant; Obtain the air flow rate entering the compressor; Obtain the target air outlet temperature of the vehicle's air conditioning system; and Obtain the current air intake temperature of the air conditioner; To obtain the specific heat capacity of air; Determining the current compressor speed of the thermal management system based on the current operating parameters includes: Calculate the temperature difference of the coolant based on the target temperature and the current temperature of the coolant; The temperature difference of the air conditioner is calculated based on the target air outlet temperature and the current air inlet temperature. The load power of the thermal management system is calculated based on the coolant flow rate, the coolant temperature difference, the coolant specific heat capacity, the air flow rate entering the compressor, the air conditioner temperature difference, and the air specific heat capacity. The current compressor speed of the thermal management system is determined based on the load power of the thermal management system.

5. The method according to claim 4, characterized in that, Determining the current compressor speed of the thermal management system based on its load power includes: Calculate the corresponding first compressor compensation speed based on the temperature difference of the air conditioner; Obtain the current actual power of the compressor; Calculate the power difference between the load power and the current actual power; Obtain the preset coolant adjustment gain; Calculate the corresponding second compressor compensation speed based on the power difference and the preset coolant adjustment gain; The current compressor speed is calculated based on the first compressor compensation speed and the second compressor compensation speed.

6. The method according to claim 1, characterized in that, The step of obtaining the current operating parameters of the thermal management system includes: Obtain the preset characteristic parameters of the battery-side refrigerant valve; Obtain the current superheat and superheat change rate of the vehicle's air conditioning; Based on the current operating parameters, determine the opening degree of the battery-side refrigerant valve, including: Calculate the first opening degree of the refrigerant valve based on the preset characteristic parameters and the current time; Calculate the second opening degree of the refrigerant valve based on the current superheat and superheat change rate of the air conditioner; The final opening degree of the battery-side refrigerant valve is determined based on the first opening degree and the second opening degree.

7. The method of claim 6, characterized in that, The step of calculating the second opening degree of the refrigerant valve based on the current superheat and the rate of change of superheat of the air conditioner includes: Obtain the preset reference superheat of the air conditioner; The dynamic safe superheat boundary of the air conditioner is calculated based on the preset benchmark superheat, the superheat change rate, and the preset superheat change coefficient; wherein, the preset superheat change coefficient varies according to the superheat change rate. The second opening degree of the refrigerant valve is obtained by performing PID calculations based on the current superheat and the dynamic safe superheat boundary.

8. The method of claim 6, characterized in that, Determining the final opening degree of the battery-side refrigerant valve based on the first opening degree and the second opening degree includes: Obtain the preset overheat threshold; Calculate the absolute value of the difference between the first opening degree and the second opening degree; If the absolute value of the opening difference is less than the preset overheat threshold, then the overheat dynamic adjustment weight coefficient is obtained; The final opening degree of the battery-side refrigerant valve is determined based on the superheat dynamic adjustment weighting coefficient, the first opening degree, and the second opening degree. If the absolute value of the opening difference is greater than or equal to the preset superheat threshold, then the final opening of the battery-side refrigerant valve is determined to be the second opening.

9. The method of claim 8, characterized in that, The process of obtaining the dynamic adjustment weighting coefficient for overheating includes: Obtain the basic overheating weight; Obtain the preset maximum allowable rate of change of superheat; The superheat dynamic adjustment weight coefficient is calculated based on the basic superheat weight, the superheat change rate, and the preset maximum allowable superheat change rate.

10. A vehicle thermal management system control device, characterized in that, include: The first processing module is used to obtain the temperature request of the vehicle battery side, determine whether the battery side needs cooling, and obtain a first determination result. The second processing module is used to obtain the temperature request of the vehicle passenger compartment side, determine whether the passenger compartment side needs cooling, and obtain a second determination result. The judgment module is used to determine whether the thermal management system needs to switch between single and dual-sided cooling based on the first judgment result and the second judgment result. The acquisition module is used to acquire the current operating parameters of the thermal management system if the thermal management system needs to switch between single and dual-sided cooling. The determination module is used to determine the current compressor speed of the thermal management system and the opening degree of the battery-side refrigerant valve based on the current operating parameters. The control module is used to control the compressor and refrigerant valve of the thermal management system according to the current compressor speed and the opening degree of the battery-side refrigerant valve, respectively.

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