A pure electric vehicle heat management multi-source heat pump control method, system and medium

Abstract

The present application relates to electric vehicle thermal management technical field, especially to a kind of pure electric vehicle thermal management multi-source heat pump control method, system and medium, the method includes the following steps, according to the heating or refrigeration request of passenger cabin, battery, combine vehicle condition, vehicle speed and ambient temperature selects corresponding multi-source heat pump control mode;Measure warm air core surface temperature T7;Calculate the difference ΔT7 of warm air core surface temperature T7 and its target temperature T7m, compressor speed is according to the difference ΔT7 PI adjustment is carried out;By adjusting the opening of three-way valve D, respectively satisfy the heating demand of battery or passenger cabin.The present application can be according to the actual operating state of vehicle, realize the timely selection of multiple heat sources, make full use of electric drive waste heat, avoid energy waste;It can work in-40 ℃ extremely low temperature field, guarantee the endurance and passenger comfort of electric vehicle in winter.Therefore, the present application can solve the technical problems of existing thermal management system, heating efficiency is relatively low, and heating capacity is insufficient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle thermal management, and in particular to a pure electric vehicle thermal management multi-source heat pump control method, system and medium. BACKGROUND

[0002] With the development of the automobile industry, especially the rise of new energy vehicles, higher requirements are put forward for the automobile thermal management system. The traditional fuel vehicle mainly focuses on engine cooling and cabin air conditioning, while the pure electric vehicle must more efficiently manage the thermal state of key components such as the battery pack and the drive motor and the comfort of the passenger cabin, as well as considering the influence of energy efficiency and range, since there is no waste heat from the internal combustion engine that can be utilized. In addition, due to the insufficient heating capacity and low heating efficiency of the existing thermal management system, the following risks may exist: poor heating effect of the passenger cabin in winter, which is not satisfactory to passengers; the defrosting and demisting functions of the passenger cabin in winter cannot be realized or are not perfect; the battery is overcooled or overheated in winter, the control is unstable, and the service life is affected; the battery has high power consumption in winter, and the range is poor.

[0003] Since the existing thermal management system generally uses a single heat pump mode, commonly used are electric drive source heat pump, air source heat pump and PTC heat pump. When the passenger cabin and the battery in the thermal management system both have heating requirements, the compressor is not enough to load the speed due to the more or less change of the load on both sides, resulting in insufficient heating capacity and low heating efficiency. Specifically, when the electric drive waste heat source is insufficient, the system mode is directly switched to air source or PTC heat source, resulting in insufficient application of electric drive waste heat, which makes the system heating capacity insufficient. In the air source heat pump mode, the fan power is too large, resulting in low energy efficiency of the thermal management system, which makes the system heating efficiency low. In the PTC heat pump mode, the PTC power is too small, resulting in insufficient heating of the thermal management system, which makes the system heating capacity insufficient; or the PTC power is too large, resulting in the compressor being cut off, thereby causing safety accidents and affecting the service life of the battery.

[0004] CN118494101A; Hunan University Suzhou Research Institute; The present application can quickly heat the battery and the passenger cabin in extremely low temperature environment. It can improve the heat utilization rate, reduce the system energy consumption, make the thermal management system more flexible, and make the automobile air conditioner can automatically select the corresponding heating / cooling mode to adjust the thermal balance of the passenger cabin and the battery pack according to different environmental temperature. However, the heat source is relatively single, the energy saving control method is relatively simple, the heating efficiency is relatively low, and the thermal management system is prone to heating insufficient problem.

[0005] CN118494141A; BYD Co. Ltd; The invention controls the temperature of the refrigerant at the inlet of the first heat exchange member to achieve uniform temperature treatment of the battery, thereby reducing the temperature difference of the battery, making the battery have better charging uniformity, and prolonging the service life of the battery. However, the control method and demand response are relatively single, the heating efficiency is low, and the problem of insufficient heating of the thermal management system is easily caused.

[0006] CN118514487A; Guangzhou Automobile Group Co. Ltd; The invention judges whether the evaporator has a frosting risk during the speed-up process of the compressor when heating and dehumidifying, and when the evaporator has a frosting risk, the compressor speed is no longer increased to avoid evaporator frosting and ensure the dehumidification effect of the evaporator. However, the control of the compressor speed and the widening of the temperature range working ability are poor, which easily leads to the problem of insufficient heating of the thermal management system.

[0007] In summary, the existing thermal management system has the problems of insufficient system heating capacity, low heating efficiency and poor control of compressor speed due to the use of a single heat pump mode, thereby affecting the range and service life of the battery. SUMMARY

[0008] The purpose of the present application is to provide a pure electric vehicle thermal management multi-source heat pump control method, system and medium, which can solve the technical problems of the existing thermal management system due to low heating efficiency and insufficient heating capacity, thereby affecting the range and service life of the battery.

[0009] To achieve the above-mentioned purpose, the present application designs a pure electric vehicle thermal management multi-source heat pump control method, which comprises the following steps,

[0010] According to the heating or cooling request of the passenger compartment and the battery, combined with the vehicle condition, vehicle speed and environmental temperature, the corresponding multi-source heat pump control mode is selected;

[0011] The surface temperature T7 of the heater core is measured;

[0012] The difference AT7 between the surface temperature T7 of the heater core and its target temperature T7m is calculated, and the compressor speed is adjusted according to the difference AT7;

[0013] For the high-temperature heating circuit, the opening of the three-way valve D is adjusted to meet the heating demand of the battery or the passenger compartment;

[0014] For the low-temperature cooling circuit, according to different multi-source heat pump control modes, it is used to recover the heat of the electric drive electronic control part and discharge the excess heat of the electric drive electronic control to the outside of the vehicle, recover the low-temperature heat in the air, and meet the battery cooling demand.

[0015] As a preferred solution, the multi-source heat pump control mode includes an electric drive source heat pump control mode, an electric drive waste heat + hot gas bypass control mode, an air source heat pump + PTC control mode, and a battery source heat pump control mode.

[0016] As a preferred solution, when the passenger compartment and the battery both issue a heating request in a driving working condition, the electric drive electric control outlet water temperature T3 is greater than -20℃, and the environmental temperature can be as low as -40℃, the electric drive source heat pump control mode is selected, and the high-temperature heating circuit and the low-temperature cooling circuit of the electric drive source heat pump control mode are as follows,

[0017] For the high-temperature heating circuit, the battery inlet temperature T5 is measured, and the opening degree of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition to meet the heating requirements of the battery and the passenger compartment, respectively.

[0018] For the low-temperature cooling circuit, the electric drive electric control outlet water temperature T3 is measured, and the opening degree of the three-way valve E and the switching of the electronic fan are controlled according to the electric drive electric control outlet water temperature T3 and the vehicle speed, so as to recover the heat of the electric drive electric control part or discharge the excess heat of the electric drive electric control to the outside of the vehicle, so that the temperature of the electric drive electric control reaches the target range value.

[0019] As a preferred solution, when the passenger compartment and the battery both issue a heating request in a driving working condition, the electric drive electric control outlet water temperature T3 is less than -20℃, and the environmental temperature can be as low as -40℃, the electric drive waste heat + hot gas bypass control mode is selected, and the high-temperature heating circuit and the low-temperature cooling circuit of the electric drive waste heat + hot gas bypass control mode are as follows,

[0020] For the high-temperature heating circuit, the battery inlet temperature T5 is measured, and the opening degree of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition to meet the heating requirements of the battery and the passenger compartment, respectively.

[0021] For the low-temperature cooling circuit, the electric drive electric control outlet water temperature T3 is measured, and the difference ΔT3 between the electric drive electric control outlet water temperature T3 and the minimum electric drive electric control outlet water temperature T3m is calculated, and the first electronic expansion valve is adjusted according to the difference ΔT3 to recover a small amount of heat of the electric drive electric control, so that the temperature of the electric drive electric control reaches the target range value.

[0022] Further, in the electric drive waste heat + hot gas bypass control mode, before the compressor speed is adjusted according to the difference ΔT7 by PI, the following steps are further included,

[0023] When the pressure P of the compressor inlet temperature pressure PT2 is greater than or equal to 1.5 bar, the compressor speed is adjusted according to the difference ΔT7 by PI;

[0024] When the pressure P in the compressor inlet temperature pressure PT2 is less than 1.5 bar, the pressure difference ΔP between the P value of the compressor inlet temperature pressure PT2 and the target pressure is measured, PI dynamic adjustment is performed through the second electronic expansion valve, air is supplied to the compressor, and the pressure P in the compressor inlet temperature pressure PT2 is greater than or equal to 1.5 bar, and then the compressor speed is PI adjusted according to the difference ΔT7.

[0025] As a preferred solution, in the parking working condition where both the passenger cabin and the battery request heating, the vehicle speed is 0 km / h, and the ambient temperature is-20℃ to 15℃, the air source heat pump+PTC control mode is selected, the high-temperature heating circuit and the low-temperature cooling circuit of the air source heat pump+PTC control mode are as follows,

[0026] For the high-temperature heating circuit, the PTC outlet coolant temperature T4 is measured and compared with the target temperature T4m; if T4>T4m, the next step is entered; if T4<T4m, the PTC is started, and the PTC is PI dynamically adjusted according to the difference ΔT4 between the PTC outlet coolant temperature T4 and the target temperature T4m, and then the next step is entered;

[0027] The battery inlet temperature T5 is measured, and the opening degree of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition to meet the heating demand of the battery and the passenger cabin, respectively.

[0028] For the low-temperature cooling circuit, the P value of the compressor inlet temperature pressure PT2 is measured, and the gear of the electronic fan is adjusted according to the P value of the PT2 to recover low-temperature heat in the air.

[0029] As a preferred solution, in the driving working condition where the passenger cabin requests heating and the battery requests cooling, the vehicle speed is greater than 0 km / h, and the ambient temperature is 5℃ to 15℃, the battery source heat pump control mode is selected, the high-temperature heating circuit and the low-temperature cooling circuit of the battery source heat pump control mode are as follows,

[0030] For the high-temperature heating circuit, the PTC outlet coolant temperature T4 is measured, the difference ΔT4 between the PTC outlet coolant temperature T4 and the target temperature T4m is calculated, and the opening degree of the three-way valve D is adjusted according to the difference ΔT4 to meet the heating demand of the passenger cabin.

[0031] For the low-temperature cooling circuit, the battery outlet temperature T6 is measured, the difference ΔT6 between the battery outlet temperature T6 and the target temperature T6m is calculated, and the first electronic expansion valve is PI adjusted according to the difference ΔT6; the four-way valve A, the three-way valve C, and the four-way valve B are adjusted, and then the low-temperature electronic water pump passes through the water-cooled evaporator to meet the battery cooling demand.

[0032] Further, in the battery source heat pump control mode, if ΔT4≥3, the electric drive electric control heat storage standby is adjusted through the three-way valve D, and the specific adjustment is as follows.

[0033] If 3≤ΔT4≤7, adjust the three-way valve D (1-2) to pass the duty ratio of 5%, (1-3) to pass the duty ratio of 95%, and simultaneously, the electric drive electric control heat storage backup is used;

[0034] If 7<ΔT4<15, adjust the three-way valve D (1-2) to pass the duty ratio of 20%, (1-3) to pass the duty ratio of 80%, and simultaneously, the electric drive electric control heat storage backup is used;

[0035] If ΔT4≥15, adjust the three-way valve D (1-2) to pass the duty ratio of 50%, (1-3) to pass the duty ratio of 50%, and simultaneously, the electric drive electric control heat storage backup is used.

[0036] The application also designs a pure electric vehicle thermal management multi-source heat pump control system, comprising a multi-source heat pump selection module, a warm air core temperature measurement module, a PI adjustment module, a high-temperature cooling module and a low-temperature cooling module.

[0037] The multi-source heat pump selection module is used for selecting a corresponding multi-source heat pump control mode according to the heating or cooling request of the passenger cabin and the battery, in combination with the vehicle condition, the vehicle speed and the environment temperature.

[0038] The warm air core temperature measurement module is used for measuring the surface temperature T7 of the warm air core.

[0039] The PI adjustment module is used for calculating the difference ΔT7 between the surface temperature T7 of the warm air core and the target temperature T7m thereof, and the compressor speed is adjusted according to the difference ΔT7.

[0040] The high-temperature cooling module is used for meeting the heating demand of the battery or the passenger cabin by adjusting the opening degree of the three-way valve D for the high-temperature heating circuit.

[0041] The low-temperature cooling module is used for recovering the heat of the electric drive electric control part and discharging the excess heat of the electric drive electric control to the outside of the vehicle, recovering the low-temperature heat in the air and meeting the battery cooling demand according to different multi-source heat pump control modes for the low-temperature cooling circuit.

[0042] The application also designs a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the above pure electric vehicle thermal management multi-source heat pump control method.

[0043] The application has the following beneficial effects:

[0044] The electric vehicle thermal management system of the application adopts the multi-source heat pump control mode, can realize the timely selection of multiple heat sources according to the actual running state of the vehicle, fully utilizes the electric drive waste heat, avoids energy waste and can effectively improve the heating capacity and heating efficiency.

[0045] 2) Can work in the field of extremely low temperature of-40 DEG C, guarantee the endurance and passenger comfort of electric vehicle in winter, further make the heating capacity greatly improve.

[0046] 3) Through intelligent control strategy, the compressor is in the optimal compression ratio, the system energy efficiency is improved, the compressor operation life is prolonged, and the heating efficiency is further greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 It is the framework diagram for the passenger cabin and battery of the application.

[0048] Figure 2 It is the flow chart of the electric drive source heat pump control mode of the application.

[0049] Figure 3 It is the flow chart of the electric drive waste heat+hot gas bypass control mode of the application.

[0050] Figure 4 It is the flow chart of the air source heat pump+PTC control mode of the application.

[0051] Figure 5 It is the framework diagram of the battery source heat pump control mode of the application.

[0052] Figure 6 It is the flow chart of the battery source heat pump control mode of the application.

[0053] BRIEF DESCRIPTION OF DRAWINGS

[0054] Refrigerant circuit: compressor 1, plate type water-cooled condenser 2, first electronic expansion valve 3, plate type water-cooled evaporator 4, second electronic expansion valve 17;

[0055] Low-temperature cooling circuit: low-temperature electronic water pump 12, low-temperature radiator 13, electronic fan 14, electric drive electric control 15, low-temperature expansion water pot 16, three-way valve E, four-way valve A, four-way valve B;

[0056] High-temperature heating circuit: high-temperature electronic water pump 5, PTC 6, warm air core 7, air blower 9, battery 10, high-temperature expansion water pot 11, three-way valve C, three-way valve D, four-way valve A, four-way valve B;

[0057] Ambient temperature Tamb, passenger cabin set temperature Tset, compressor low-pressure side minimum operating temperature Ta, compressor low-pressure side maximum operating temperature Tb;

[0058] Electric drive electric control outlet water temperature T3, electric drive electric control minimum temperature T3m, electric drive electric control upper limit temperature Td, electric drive electric control water temperature difference ΔT3 (ΔT3=T3-T3m);

[0059] PTC outlet coolant temperature T4, PTC target temperature T4m, PTC temperature difference ΔT4 (ΔT4 = T4 - T4m) ;

[0060] Battery inlet temperature T5, battery outlet temperature T6, battery target water temperature Tbattery, battery temperature difference ΔT6 (ΔT6 = T6 - Tbattery) ;

[0061] Warm air core surface temperature T7, warm air core target temperature T7m, warm air core temperature difference ΔT7 (ΔT7 = T7 - T7m) ;

[0062] ΔT7 (ΔT7 = T7 - T7m) ;

[0063] Condenser outlet refrigerant temperature T, P corresponding to the saturation temperature Te in PT2, superheat ΔSh (ΔSh = T - Te), target superheat ΔShm;

[0064] Compressor outlet temperature pressure PT1, compressor inlet temperature pressure PT2, pressure P of PT2, compressor target pressure Pm, pressure difference ΔP (ΔP = P - Pm). DETAILED DESCRIPTION

[0065] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the present application will be further described below in conjunction with the accompanying drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, in order to facilitate the description, only the parts related to the present application are shown in the drawings, not all.

[0066] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixed connection, or it can be detachable connection; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0067] The present application relates to a control method of automobile thermal management heat pump, mainly to realize the control method of multi-source heat pump (electric drive source heat pump, electric drive waste heat + hot gas bypass, battery source heat pump, air source heat pump + PTC) in a system architecture diagram. Under the condition that the external conditions and the customer's demand for vehicle are changing, how to meet the demand of wide low temperature (-40℃ ~ 15℃) whole vehicle thermal management and the demand of passenger cabin passengers through control method, and realize efficient recycling of energy, reduce the demand for battery power, and improve the vehicle range.

[0068] PTC (Positive Temperature Coefficient, positive temperature coefficient) PTC heater is a new energy automobile air conditioning component using the positive temperature coefficient characteristics of PTC material for heating. When the PTC element is powered on, its resistance value will increase with the increase of temperature, so more heat will be generated, thereby achieving the purpose of heating. The PTC heater has the advantages of fast heating speed, low energy consumption, high safety, etc., and is widely used in new energy vehicles.

[0069] The application provides a pure electric vehicle thermal management multi-source heat pump control method, system and medium, and a model is built through SIMULINK software, and the model is integrated with a whole vehicle model of the pure electric vehicle, and the electric device is controlled according to the control method. The application solves the above problems through the technical breakthrough and innovation of the control method, parameter calibration, logic definition and valve matching, improves the endurance mileage, meets the thermal management requirements of the cabin as much as possible, and guarantees sufficient safety. In different heat source modes, different multi-source heat pump control modes are selected, and the adaptability is high. The pure electric vehicle thermal management multi-source heat pump system mode control method provided by the application optimizes the heat flow of the whole vehicle through an intelligent control strategy, realizes efficient recovery of electric drive heat and absorption of external environmental heat, reduces the demand for battery power, improves the endurance mileage of the whole vehicle, and has an optimal mode selection strategy and control method, wide temperature range adaptability and refrigerant adaptability. In addition, the compressor is in a suitable compression ratio state when running at low temperature, so that the efficiency and service life of the compressor can be improved.

[0070] The pure electric vehicle thermal management multi-source heat pump control method provided by the application comprises the following steps,

[0071] According to the heating or cooling request of the passenger cabin and the battery, in combination with the vehicle condition, the vehicle speed and the environment temperature, a corresponding multi-source heat pump control mode is selected, and the multi-source heat pump control mode comprises an electric drive source heat pump control mode, an electric drive waste heat + hot gas bypass control mode, an air source heat pump + PTC control mode and a battery source heat pump control mode.

[0072] The surface temperature T7 of the heater core is measured.

[0073] The difference AT7 between the surface temperature T7 of the heater core and the target temperature T7m of the heater core is calculated, and the compressor speed is adjusted according to the difference AT7.

[0074] For the high-temperature heating circuit, the opening degree of the three-way valve D is adjusted to meet the heating requirements of the battery or the passenger cabin.

[0075] For the low-temperature cooling loop, according to different multi-source heat pump control modes, the low-temperature heat in the air is recovered, and the battery refrigeration demand is met.

[0076] It should be understood that the specific order or hierarchy of steps in the processes disclosed herein is an example. Based on design preferences, it is understood that the specific order or hierarchy of steps in the processes can be rearranged, and further it is understood that some of the steps can be performed concurrently, that the amount of intermediary steps or the process flow can be adjusted, and that the accompanying claims are not intended to be limited to the precise order or hierarchy presented.

[0077] The application further provides a multi-source heat pump control system for thermal management of a pure electric vehicle, comprising a multi-source heat pump selection module, a temperature measurement module of a heater core, a PI adjustment module, a high-temperature cooling module and a low-temperature cooling module.

[0078] The multi-source heat pump selection module is configured to select a corresponding multi-source heat pump control mode according to a heating or cooling request from the passenger cabin and the battery, in combination with the vehicle condition, the vehicle speed and the ambient temperature.

[0079] The temperature measurement module of the heater core is configured to measure the surface temperature T7 of the heater core.

[0080] The PI adjustment module is configured to calculate the difference ΔT7 between the surface temperature T7 of the heater core and the target temperature T7m of the heater core, and the compressor speed is adjusted according to the difference ΔT7.

[0081] The high-temperature cooling module is configured to adjust the opening degree of a three-way valve D for a high-temperature heating loop, so as to meet the heating demand of the battery or the passenger cabin.

[0082] The low-temperature cooling module is configured to recover the heat of the electric drive and the electric control part and discharge the excess heat of the electric drive and the electric control part to the outside of the vehicle, and recover the low-temperature heat in the air, so as to meet the battery refrigeration demand, according to different multi-source heat pump control modes.

[0083] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the multi-source heat pump control method for thermal management of a pure electric vehicle.

[0084] The technical solutions of the application will be further described below with reference to the drawings.

[0085] The application introduces in detail a pure electric vehicle heat management multi-source heat pump (electric drive source heat pump, electric drive waste heat + hot gas bypass, battery source heat pump, air source heat pump + PTC) system mode control method, which is composed of a compressor 1, a plate water-cooled condenser 2, a first electronic expansion valve 3, a plate water-cooled evaporator 4, a second electronic expansion valve 17, a high-temperature electronic water pump 5, a PTC 6, a warm air core 7, a water-cooled evaporator 8, a blower 9, a battery 10, an expansion water kettle 11, a low-temperature electronic water pump 12, a low-temperature radiator 13, an electronic fan 14, an electric drive electronic control 15, the expansion water kettle 16, a four-way valve A, a four-way valve B, a three-way valve C, a three-way valve D and a three-way valve E. Figure 1 、 3 The dark line in 5 indicates that the loop is connected, and the light gray line indicates that the loop is disconnected.

[0086] Figure 1 It is a framework diagram for heating the passenger compartment and the battery simultaneously, and is suitable for electric drive source heat pump control mode, electric drive waste heat + hot gas bypass control mode and air source heat pump + PTC control mode.

[0087] The refrigerant circuit is shown in detail in Figure 1 The intermediate black dashed line loop, the plate water-cooled evaporator 4 absorbs the waste heat of the electric drive electronic control 15 on the cooling liquid side through the low-temperature electronic water pump 12, the plate water-cooled evaporator 4 changes from a low-temperature low-pressure liquid to a low-temperature low-pressure gas, becomes a high-temperature high-pressure gas after being compressed by the compressor 1, and then transfers the high-temperature heat to the antifreeze through the plate water-cooled condenser 2, so that the refrigerant side becomes a medium-temperature high-pressure liquid, which is throttled into a low-temperature low-pressure liquid by the first electronic expansion valve 3 and returns to the plate water-cooled evaporator 4. When the electric drive waste heat is not enough, the inlet temperature and pressure PT2 of the compressor 1 will be too low, at which time the second electronic expansion valve 17 needs to be opened to increase the pressure of PT2 to ensure the stable operation of the compressor.

[0088] The low-temperature cooling circuit is shown in detail in Figure 1 The left black dashed line loop circulates through the plate water-cooled evaporator 4 cooling liquid side, the four-way valve A (1-2), the three-way valve E (1-3), the electric drive electronic control 15, the four-way valve B (1-2) and the low-temperature electronic water pump 12 to transfer the heat of the electric drive electronic control 15 to the plate water-cooled evaporator 4. When the heat of the electric drive electronic control 15 is too much, the heat is transferred to the low-temperature radiator 13 through the three-way valve E (2-3), and then the heat is discharged to the air outside the vehicle through the electronic fan 14.

[0089] The high-temperature heating circuit is shown in detail in Figure 1The right side black solid line circuit, through the high-temperature electronic water pump 5 circulates the cooling liquid side of the plate water-cooled condenser 2, the three-way valve D (1-3), and / or the PTC 6, one of the heat is transmitted to the heater core 7, and the cold air is exchanged with the heater core 7 by the air blower 9 to transmit the heat to the passenger cabin to meet the heating demand of the passenger cabin; the other heat is transmitted to the battery heating through the three-way valve D (1-2), the four-way valve A (3-4), and the three-way valve C (1-3) to meet the battery heating demand.

[0090] 1. The electric drive source heat pump control mode;

[0091] As shown in Figure 1 , 2 The electric drive source heat pump control mode is applicable to the driving working condition that both the passenger cabin and the battery issue a heating request, the electric drive electric control outlet water temperature T3 is greater than -20℃, and the environmental temperature can be as low as -40℃.

[0092] The control method of the electric drive source heat pump control mode specifically includes the following steps:

[0093] Measuring the heater core surface temperature T7;

[0094] Calculating the difference ΔT7 between the heater core surface temperature T7 and the target temperature T7m, and the compressor speed is adjusted according to the difference ΔT7;

[0095] For the high-temperature heating circuit, the battery inlet temperature T5 is measured, the opening degree of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition, and the heating demands of the battery and the passenger cabin are met respectively; the three-way valve D (1-2) has a duty ratio of 1-X1, which meets the battery heating demand; the three-way valve D (1-3) has a duty ratio of X1, which meets the passenger cabin heating demand;

[0096] For the low-temperature cooling circuit, the electric drive electric control outlet water temperature T3 is measured, the opening degree of the three-way valve E and the switch of the electronic fan are controlled according to the electric drive electric control outlet water temperature T3 and the vehicle speed, which is used to recover part of the heat of the electric drive electric control or to discharge the excess heat of the electric drive electric control to the outside of the vehicle, so that the temperature of the electric drive electric control reaches the target range value; the three-way valve E (1-3) has a duty ratio of X2, which is used to recover part of the heat of the electric drive electric control; the three-way valve E (2-3) has a duty ratio of 1-X2, which is used to judge the opening and closing of the electronic fan according to the vehicle speed and the environmental temperature, and to discharge the excess heat of the electric drive electric control to the outside of the vehicle.

[0097] In combination with Figure 2When the passenger cabin and the battery both request heating, the compressor performs PI (proportional-integral) dynamic adjustment according to the temperature difference ΔT7, and distributes the heat flow through proportional adjustment of the opening degree of the three-way valve D to meet the heating requirements of the passenger cabin and the battery under different vehicle conditions; the heat of the electric drive electronic control 15 is reasonably distributed through the control of the three-way valve D and the electronic fan to improve the refrigeration performance of the passenger cabin and the battery heating, the refrigeration performance coefficient = heating capacity / electric power consumption, thereby prolonging the cruising range of the vehicle.

[0098] The control method of the compressor 1: measure the temperature T7 of the surface of the heater core, calculate the temperature difference ΔT7 between the temperature T7 of the surface of the heater core and the target temperature T7m, and perform PI dynamic adjustment of the compressor speed according to the temperature difference ΔT7, the target speed of the compressor = the current speed of the compressor + P + I, P = Kp*ΔT7, I = Ki*ΔT7; wherein P is the change amount of the speed of the compressor calculated by the proportional coefficient, in rpm; Kp is the proportional coefficient; I is the change amount of the speed of the compressor calculated by the integral coefficient, in rpm; Ki is the integral coefficient. The corresponding relationship between the target temperature T7m of the heater core and the ambient temperature Tamb and the set temperature Tset of the passenger cabin can be converted by a calibration function.

[0099] The control mode of the first electronic expansion valve 3: calculate the superheat ΔSh by the measured value P of the compressor inlet temperature pressure PT2, and perform PI control according to the target superheat ΔShm = 5K; the superheat ΔSh = T (condenser outlet refrigerant temperature) - Te (the saturation temperature corresponding to the P value in PT2).

[0100] The control mode of the three-way valve D: simultaneously satisfy the heating of the passenger cabin and the battery by adjusting the opening degree of the three-way valve D, and the battery is divided into heating levels according to the inlet temperature T5, see Table 1 below for details.

[0101] Table 1

[0102]

[0103] The control mode of the three-way valve E and the electronic fan: measure the outlet water temperature T3 of the electric drive electronic control 15, when Ta < T3 < Tb, the three-way valve E (1-3) is used to recover part of the heat of the electric drive electronic control; Ta is the lowest operating temperature on the low-pressure side of the compressor, which is -10℃; Tb is the highest operating temperature on the low-pressure side of the compressor, which is 30℃. When T3 > Tb, the heat of the electric drive electronic control is too much, the three-way valve E (2-3) is adjusted to make the cooling liquid pass through the low-temperature radiator 13 and the electronic fan 14 to discharge the excessive heat to the air outside the vehicle, and the control mode is shown in Table 2, where the low speed of the electronic fan refers to 1000 rpm.

[0104] Table 2

[0105]

[0106]

[0107] 2. Electric drive waste heat + hot gas bypass control mode;

[0108] See Figure 3 The electric drive waste heat + hot gas bypass control mode is applicable to the driving working condition that both the passenger cabin and the battery issue heating requests, the electric drive electric control outlet water temperature T3 is less than -20℃, and the ambient temperature can be as low as -40℃.

[0109] The control method of the electric drive waste heat + hot gas bypass control mode specifically includes the following steps:

[0110] Measure the temperature T7 of the surface of the heater core;

[0111] Calculate the difference ΔT7 between the temperature T7 of the surface of the heater core and the target temperature T7m thereof, when the pressure P of the compressor inlet temperature pressure PT2 is greater than or equal to 1.5 bar, proceed to the next step; when the pressure P of the compressor inlet temperature pressure PT2 is less than 1.5 bar, measure the pressure difference ΔP between the P value of the compressor inlet temperature pressure PT2 and the target pressure, perform PI dynamic adjustment through the second electronic expansion valve 17, supply air to the compressor, so that the pressure P of the compressor inlet temperature pressure PT2 is greater than or equal to 1.5 bar, and then proceed to the next step;

[0112] The compressor speed is adjusted according to the difference ΔT7;

[0113] For the high-temperature heating circuit, measure the battery inlet temperature T5, adjust the opening degree of the three-way valve D according to the battery inlet temperature T5 and the vehicle condition, and meet the heating requirements of the battery and the passenger cabin respectively; the three-way valve D(1-2) has a duty ratio of 1-X1, which meets the battery heating requirement; the three-way valve D(1-3) has a duty ratio of X1, which meets the passenger cabin heating requirement;

[0114] For the low-temperature cooling circuit, measure the electric drive electric control outlet water temperature T3, calculate the difference ΔT3 between the electric drive electric control outlet water temperature T3 and the electric drive electric control minimum temperature T3m, and the first electronic expansion valve 3 performs PI dynamic adjustment according to the difference ΔT3 to recover a small amount of heat from the electric drive electric control, so that the temperature of the electric drive electric control reaches the target range value.

[0115] In combination with Figure 3When the passenger cabin and the battery both make heating requests, the compressor performs PI dynamic adjustment according to the temperature difference ΔT7, and distributes the heat flow through proportional adjustment of the three-way valve D to meet the heating requirements of the passenger cabin and the battery under different vehicle conditions; when the electric drive waste heat is insufficient, the second electronic expansion valve 17 needs to be adjusted to supply air to the compressor to increase the pressure of the compressor inlet temperature pressure PT2, so as to ensure stable operation of the compressor; by increasing the compression ratio through increasing the compressor speed, the power consumption heat is increased, in simple terms, the compressor is regarded as a PTC, and a part of the heat in the electric drive + most of the power consumption of the compressor is absorbed, so as to meet the heating of the passenger cabin and the battery.

[0116] The compressor 1 control method: measure the warm air core surface temperature T7, calculate the temperature difference ΔT7 between the surface temperature T7 and the target temperature T7m, and the compressor speed is adjusted according to the temperature difference ΔT7, the target speed of the compressor = the current speed of the compressor + P + I, P = Kp*ΔT7, I = Ki*ΔT7. The corresponding relationship between the warm air core target temperature T7m and the ambient temperature Tamb and the passenger cabin set temperature Tset can be converted by a calibration function.

[0117] The control method of the first electronic expansion valve 3: through the water temperature difference ΔT3 between the outlet water temperature T3 of the electric drive electronic control 15 and the minimum temperature T3m (calibration value) of the electric drive electronic control, the first electronic expansion valve 3 adjusts according to the water temperature difference ΔT3 and through the low-temperature electronic water pump 12 and the plate-type water-cooled evaporator 4 to recover a small part of the heat of the electric drive electronic control.

[0118] The control method of the second electronic expansion valve 17: through the pressure difference ΔP between the pressure P value of the compressor inlet temperature pressure PT2 and the target pressure Pm, ΔP = P-Pm, the second electronic expansion valve 17 adjusts according to the pressure difference ΔP to supply air to the compressor, increase the pressure of the compressor inlet temperature pressure PT2, and ensure stable operation of the compressor.

[0119] The control method of the three-way valve D: adjust the duty cycle X1 of the three-way valve D to simultaneously meet the heating of the passenger cabin and the battery, and the battery is heated according to the inlet temperature T5 to distinguish the heating level, which is the same as Table 1 above.

[0120] 3. Air source heat pump + PTC control mode;

[0121] For details Figure 4 The air source heat pump + PTC control mode is applicable to the parking working condition that the passenger cabin and the battery both make heating requests, and the vehicle speed is 0 kmh and the ambient temperature is-20℃-15℃.

[0122] The control method of the air source heat pump + PTC control mode, specifically includes the following steps:

[0123] Measure the warm air core surface temperature T7;

[0124] The difference ΔT7 between the warm air core sub-surface temperature T7 and the target temperature T7m is calculated, and the compressor speed is adjusted according to the difference ΔT7;

[0125] For the high-temperature heating circuit, first, the PTC outlet coolant temperature T4 is measured and compared with the target temperature T4m; if T4>T4m, the next step is entered; if T4<T4m, the PTC is started, and the PTC is dynamically adjusted according to the difference ΔT4 between the PTC outlet coolant temperature T4 and the target temperature T4m, and then the next step is entered;

[0126] Secondly, the battery inlet temperature T5 is measured, and the opening degree of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition to meet the heating requirements of the battery and the passenger compartment respectively; the three-way valve D(1-2) has a duty ratio of 1-X1, which meets the battery heating requirement; the three-way valve D(1-3) has a duty ratio of X1, which meets the passenger compartment heating requirement;

[0127] For the low-temperature cooling circuit, the P value of the inlet temperature pressure PT2 of the compressor 1 is measured, and the gear of the electronic fan is adjusted according to the P value of PT2 to recover the low-temperature heat in the air.

[0128] In combination Figure 4 When the passenger compartment and the battery both issue a heating request, the compressor is dynamically adjusted according to the temperature difference ΔT7, the low-temperature cooling circuit absorbs the low-temperature heat of the external air through the electronic water pump, low-temperature radiator circulation and electronic fan gear control; the water-cooled plate evaporator 4 absorbs low-temperature heat on the coolant side, and the refrigerant side evaporates into low-temperature and low-pressure gas back to the compressor, which is compressed into high-temperature and high-pressure gas by the compressor; then the water-cooled condenser 2 is used to heat the passenger compartment and the battery, and when the heating demand of the passenger compartment and the battery is not enough, the PTC 6 is started to supplement the heat, so as to meet the heating demand of the passenger compartment and the battery under different ambient temperature conditions.

[0129] The control method of the compressor 1: measure the warm air core sub-surface temperature T7, calculate the temperature difference ΔT7 between the warm air core sub-surface temperature T7 and the target temperature T7m, and dynamically adjust the compressor speed according to the temperature difference ΔT7, the target speed of the compressor = the current speed of the compressor + P + I, P = Kp*ΔT7, I = Ki*ΔT7. The corresponding relationship between the target temperature T7m of the warm air core sub and the ambient temperature Tamb and the passenger compartment set temperature Tset can be converted by a calibration function.

[0130] The control method of the first electronic expansion valve 3: calculate the superheat ΔSh by the measured value of PT2, and perform PI control according to the target superheat ΔShm=5K; the superheat ΔSh=T(temperature of the refrigerant at the outlet of the condenser)-Te(P corresponding to the saturation temperature in PT2).

[0131] Electronic fan 14 control mode: control electronic fan gear according to P value of PT2, control see table 3.

[0132] Table 3

[0133] P value of PT2 3 bar < P 1.8 < P < 3 bar P < 1.8 bar Fan gear Low gear Mid gear High gear

[0134] Three-way valve D control mode: adjust three-way valve D duty cycle X1 to meet passenger compartment and battery heating at the same time, battery heating level is divided according to inlet temperature T5, same as table 1 above.

[0135] PTC control mode: measure PTC outlet coolant temperature T4, calculate PTC outlet coolant temperature and target temperature T4m temperature difference ΔT4, PTC is adjusted according to temperature difference ΔT4, PTC adjustment range under different environment temperature, see table 4.

[0136] Table 4

[0137]

[0138] 4. Battery source heat pump control mode;

[0139] See Figure 5 , 6 Battery source heat pump control mode is applicable to driving conditions where passenger compartment sends heating request and battery sends cooling request, vehicle speed is greater than 0kmh, and environment temperature is 5℃-15℃.

[0140] The control method of the battery source heat pump control mode, specifically includes the following steps:

[0141] Measure the surface temperature of the heater core;

[0142] Calculate the difference ΔT7 between the surface temperature T7 of the heater core and its target temperature T7m, and adjust the compressor speed according to the difference ΔT7;

[0143] For high temperature heating circuit, measure PTC outlet coolant temperature T4, calculate the difference ΔT4 between PTC outlet coolant temperature T4 and its target temperature T4m, and adjust the opening of three-way valve D according to the size of the difference ΔT4 to meet the heating demand of passenger compartment;

[0144] If ΔT4<3, adjust three-way valve D (1-2) duty cycle to 0%, and (1-3) duty cycle to 100%;

[0145] If 3≤ΔT4≤7, adjust three-way valve D (1-2) duty cycle to 5%, and (1-3) duty cycle to 95%, and at the same time, electric drive electronic control heat storage standby;

[0146] If 7 < ΔT4 < 15, adjust the three-way valve D (1-2) to 20% duty cycle, (1-3) to 80% duty cycle, and the electric drive electric control heat storage standby is simultaneously adjusted;

[0147] If ΔT4 ≥ 15, adjust the three-way valve D (1-2) to 50% duty cycle, (1-3) to 50% duty cycle, and the electric drive electric control heat storage standby is simultaneously adjusted;

[0148] For the low-temperature cooling circuit, the battery outlet temperature T6 is measured, the difference ΔT6 between the battery outlet temperature T6 and the target temperature T6m is calculated, and the first electronic expansion valve 3 is adjusted according to the difference ΔT6; the four-way valve A (2-3), the three-way valve C (1-3), and the four-way valve B (1-4) are adjusted, and then the low-temperature electronic water pump 12 circulates to the water-cooled evaporator 4 to meet the battery refrigeration demand.

[0149] Refrigerant circuit: see Figure 5 The intermediate dashed line circuit, the plate water-cooled evaporator 4 circulates to absorb the heat of the battery 10 on the cooling liquid side through the low-temperature electronic water pump 12, and the plate water-cooled evaporator 4 on the refrigerant side changes from low-temperature low-pressure liquid to low-temperature low-pressure gas; after being compressed by the compressor 1, it becomes high-temperature high-pressure gas, and then the high-temperature heat is transferred to the antifreeze through the plate water-cooled condenser 2, and the refrigerant side becomes medium-temperature high-pressure liquid, which is throttled by the first electronic expansion valve 3 to become low-temperature low-pressure liquid and returns to the plate evaporator 4.

[0150] Battery cooling liquid circuit: see Figure 5 The intermediate dashed line circuit, the plate water-cooled evaporator 4 circulates to absorb the heat of the battery 10 on the cooling liquid side through the low-temperature electronic water pump 12, and the plate water-cooled evaporator 4 on the refrigerant side changes from low-temperature low-pressure liquid to low-temperature low-pressure gas; after being compressed by the compressor 1, it becomes high-temperature high-pressure gas, and then the high-temperature heat is transferred to the antifreeze through the plate water-cooled condenser 2, and the refrigerant side becomes medium-temperature high-pressure liquid, which is throttled by the first electronic expansion valve 3 to become low-temperature low-pressure liquid and returns to the plate evaporator 4.

[0151] High-temperature heating circuit: see Figure 5 The intermediate solid line circuit, the high-temperature electronic water pump 5 circulates to transfer heat to the heater core 7 through the plate water-cooled condenser 2 on the cooling liquid side and the three-way valve D (1-3), and the cold air exchanges heat with the heater core 7 through the air blower 9 to transfer heat to the passenger compartment to meet the heating demand of the passenger compartment.

[0152] In combination Figure 6 When the passenger compartment requests heating and the battery requests refrigeration, the compressor is dynamically adjusted according to the water temperature difference ΔT6, and when the battery side refrigeration is prioritized, the heat flow is distributed by the three-way valve D to meet the heating demand of the passenger compartment at different set temperatures.

[0153] When T4m < T4 < Td (T4m is the PTC target temperature, T4 is the PTC outlet coolant temperature, Td is the upper limit temperature of the electric drive control, and is 65 DEG C), heat is transferred to the electric drive control 15 for heat storage by adjusting the opening of the three-way valve D (1-2), the four-way valve A (1-4), and the three-way valve E (1-3). The control mode of the three-way valve D is shown in Table 5 below.

[0154] Table 5

[0155]

[0156] The control mode of the compressor 1: PI dynamic adjustment is performed according to the difference AT6 between the battery target water temperature Tbattery and the battery outlet temperature T6, where AT6 = T6 - Tbattery.

[0157] The control mode of the first electronic expansion valve 3: the superheat degree ASH is calculated by measuring the P value of the compressor inlet temperature pressure PT2, and PI control is performed according to the target superheat degree ASHm = 5K; the superheat degree ASH = T (condenser outlet refrigerant temperature) - Te (the P corresponding saturated temperature in PT2).

[0158] In summary, the pure electric vehicle heat management multi-source heat pump system mode control method and system of the application has the following advantages:

[0159] 1. Dynamic mode adjustment: when the passenger compartment and the battery both have heating requirements, the working mode of the heat pump can be dynamically adjusted according to the actual operating conditions of the vehicle (such as the ambient temperature, the battery state, the electric drive temperature, the passenger compartment air conditioning set temperature, the inside and outside circulating air door state, etc.), precise temperature control is realized, and the overall energy efficiency is improved. Electric drive source heat pump, electric drive waste heat + hot gas bypass, battery source heat pump, air source heat pump + PTC multiple heat source heating can be realized. According to the actual operating state of the vehicle, multiple heat sources can be selected in time, the electric drive waste heat is fully utilized, and energy waste is avoided.

[0160] 2. Wide temperature range working ability: for extreme climate conditions, the multi-source heat pump system can heat at -40 DEG C, ensuring the endurance and passenger comfort of the electric vehicle in winter. It can work in the field of -40 DEG C extremely low temperature, ensuring the endurance and passenger comfort of the electric vehicle in winter.

[0161] 3. Energy saving: by setting the target temperature of the passenger compartment redundantly, the compressor speed is adjusted to meet the heating needs of both the passenger compartment and the battery, and the three-way water valve of the antifreeze circuit is proportionally adjusted to distribute the antifreeze flow to the passenger compartment and the battery, avoiding the situation that when the passenger compartment and the battery meet the demand on one side, the compressor is not loaded, causing the other side to not meet the demand. When the electric drive waste heat is not enough, by opening the refrigerant hot gas bypass circuit, it avoids the problem of low energy efficiency caused by directly switching to air source heat pump or PTC mode; when the battery has waste heat, the antifreeze flow can be adjusted to meet the passenger compartment heat demand and the motor heat storage demand, avoiding the waste of energy caused by directly dissipating into the environment; in the air source heat pump+PTC mode, by adjusting the compressor low pressure control electronic fan gear position, the PTC power at different refrigerant species and ambient temperatures is calibrated, so that the compressor is in a better compression ratio state, and the system energy efficiency is improved. Through intelligent control strategy, the compressor is in a better compression ratio, the system energy efficiency is improved, and the compressor operating life is prolonged.

[0162] 4. Architecture diagram applicability: applicable to R134a, R1234yf, R290 refrigerant.

[0163] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A multi-source heat pump control method for thermal management of pure electric vehicles, characterized in that: Comprise the following steps, According to the heating or cooling request of the passenger cabin and the battery, combined with the vehicle condition, vehicle speed and environmental temperature, the corresponding multi-source heat pump control mode is selected; The temperature T7 of the warm air core surface is measured; The difference ΔT7 between the temperature T7 of the warm air core surface and the target temperature T7m is calculated, and the compressor speed is adjusted according to the difference ΔT7; For the high-temperature heating circuit, the opening of the three-way valve D is adjusted to meet the heating demand of the battery or the passenger cabin respectively; For the low-temperature cooling circuit, according to different multi-source heat pump control modes, the low-temperature heat in the air is recovered, and the excess heat of the electric drive and control is discharged to the outside of the vehicle, to meet the battery cooling demand; The multi-source heat pump control mode includes an electric drive source heat pump control mode, an electric drive waste heat + hot gas bypass control mode, an air source heat pump + PTC control mode, and a battery source heat pump control mode; When the passenger cabin and the battery both issue a heating request in the driving condition, the electric drive and control outlet water temperature T3 is greater than-20℃, and the environmental temperature can be as low as-40℃, the electric drive source heat pump control mode is selected; When the passenger cabin and the battery both issue a heating request in the driving condition, the electric drive and control outlet water temperature T3 is less than-20℃, and the environmental temperature can be as low as-40℃, the electric drive waste heat + hot gas bypass control mode is selected; When the passenger cabin and the battery both issue a heating request in the parking condition, the vehicle speed is 0 km / h, and the environmental temperature is-20℃ to 15℃, the air source heat pump + PTC control mode is selected; When the passenger cabin issues a heating request and the battery issues a cooling request in the driving condition, the vehicle speed is greater than 0 km / h, and the environmental temperature is 5℃ to 15℃, the battery source heat pump control mode is selected.

2. The control method of claim 1, wherein: The high-temperature heating circuit and the low-temperature cooling circuit of the electric drive source heat pump control mode are as follows, For the high-temperature heating circuit, the battery inlet temperature T5 is measured, and the opening of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition, to meet the heating demand of the battery and the passenger cabin respectively; For the low-temperature cooling circuit, the electric drive and control outlet water temperature T3 is measured, and the opening of the three-way valve E and the switch of the electronic fan are controlled according to the electric drive and control outlet water temperature T3 and the vehicle speed, to recover the heat of the electric drive and control part or discharge the excess heat of the electric drive and control to the outside of the vehicle, so that the temperature of the electric drive and control reaches the target range value.

3. The control method of claim 2, wherein: The high-temperature heating circuit and the low-temperature cooling circuit of the electric drive waste heat + hot gas bypass control mode are as follows, For the high-temperature heating circuit, the battery inlet temperature T5 is measured, and the opening of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition, to meet the heating demand of the battery and the passenger cabin respectively; For the low-temperature cooling circuit, the electric drive and control outlet water temperature T3 is measured, and the difference ΔT3 between the electric drive and control outlet water temperature T3 and the lowest temperature T3m of the electric drive and control is calculated, and the first electronic expansion valve is adjusted according to the difference ΔT3 to recover part of the heat of the electric drive and control, so that the temperature of the electric drive and control reaches the target range value.

4. The pure electric vehicle thermal management multi-source heat pump control method according to claim 3, characterized in that: In the electric drive waste heat + hot gas bypass control mode, before the compressor speed is adjusted according to the difference ΔT7, the temperature T7 of the warm air core surface is measured, and the difference ΔT7 between the temperature T7 of the warm air core surface and the target temperature T7m is calculated, and the compressor speed is adjusted according to the difference ΔT7. Comprise the following steps, When the pressure P in the compressor inlet temperature pressure PT2 is greater than or equal to 1.5 bar, the compressor speed is adjusted according to the difference ΔT7 by PI regulation; When the pressure P in the compressor inlet temperature pressure PT2 is less than 1.5 bar, the pressure difference ΔP between the P value of the compressor inlet temperature pressure PT2 and the target pressure is measured, and the second electronic expansion valve is adjusted by PI dynamic regulation to supply air to the compressor, so that the pressure P in the compressor inlet temperature pressure PT2 is greater than or equal to 1.5 bar, and then the compressor speed is adjusted according to the difference ΔT7 by PI regulation.

5. The control method of claim 2, wherein: The high-temperature heating circuit and the low-temperature cooling circuit of the air source heat pump+PTC control mode are as follows, For the high-temperature heating circuit, the PTC outlet coolant temperature T4 is measured and compared with the target temperature T4m; if T4>T4m, the next step is entered; if T4<T4m, the PTC is started, and the PTC is adjusted by PI dynamic regulation according to the difference ΔT4 between the PTC outlet coolant temperature T4 and the target temperature T4m, and then the next step is entered; The battery inlet temperature T5 is measured, and the opening degree of the three-way valve D is adjusted according to the battery inlet temperature T5 and the vehicle condition to meet the heating demand of the battery and the passenger compartment respectively; For the low-temperature cooling circuit, the P value of the compressor inlet temperature pressure PT2 is measured, and the gear of the electronic fan is adjusted according to the P value of the PT2 to recover low-temperature heat in the air.

6. The control method of claim 2, wherein: The high-temperature heating circuit and the low-temperature cooling circuit of the battery source heat pump control mode are as follows, For the high-temperature heating circuit, the PTC outlet coolant temperature T4 is measured, and the difference ΔT4 between the PTC outlet coolant temperature T4 and the target temperature T4m is calculated, and the opening degree of the three-way valve D is adjusted according to the size of the difference ΔT4 to meet the heating demand of the passenger compartment; For the low-temperature cooling circuit, the battery outlet temperature T6 is measured, the difference ΔT6 between the battery outlet temperature T6 and the target temperature T6m is calculated, and the first electronic expansion valve is adjusted by PI according to the difference ΔT6; the four-way valve A, the three-way valve C and the four-way valve B are adjusted respectively, and then the low-temperature electronic water pump passes through the water-cooled evaporator to meet the battery refrigeration demand.

7. The control method of claim 6, wherein: In the battery source heat pump control mode, if ΔT4≥3℃, the three-way valve D is adjusted to reserve the electric drive electric control heat, which is as follows, If 3℃≤ΔT4≤7℃, the duty ratio of the first interface and the second interface of the three-way valve D is 5%, the duty ratio of the first interface and the third interface is 95%, and the electric drive electric control heat is reserved at the same time; If 7℃<ΔT4<15℃, the duty ratio of the first interface and the second interface of the three-way valve D is 20%, the duty ratio of the first interface and the third interface is 80%, and the electric drive electric control heat is reserved at the same time; If ΔT4≥15℃, the duty ratio of the first interface and the second interface of the three-way valve D is 50%, the duty ratio of the first interface and the third interface is 50%, and the electric drive electric control heat is reserved at the same time.

8. A pure electric vehicle thermal management multi-source heat pump control system, characterized in that: It comprises a multi-source heat pump selection module, a warm air core temperature measurement module, a PI regulation module, a high-temperature cooling module and a low-temperature cooling module. The multi-source heat pump selection module is configured to select a corresponding multi-source heat pump control mode according to a heating or cooling request issued by the passenger cabin and the battery, in combination with a vehicle condition, a vehicle speed, and an ambient temperature; The heating core temperature measurement module is configured to measure a heating core surface temperature T7; The PI adjustment module is configured to calculate a difference AT7 between the heating core surface temperature T7 and a target temperature T7m of the heating core, and to perform PI adjustment on a compressor speed according to the difference AT7; The high-temperature cooling module is configured to meet heating requirements of the battery or the passenger cabin by adjusting an opening degree of a three-way valve D for a high-temperature heating circuit; The low-temperature cooling module is configured to recover heat of an electric drive electronic control part and discharge excess heat of the electric drive electronic control part to the outside of the vehicle, recover low-temperature heat in the air, and meet battery cooling requirements for a low-temperature cooling circuit according to different multi-source heat pump control modes; The multi-source heat pump control modes include an electric drive source heat pump control mode, an electric drive waste heat + hot air bypass control mode, an air source heat pump + PTC control mode, and a battery source heat pump control mode. When the passenger cabin and the battery both issue a heating request in a driving condition, the electric drive electronic control outlet water temperature T3 is greater than -20℃, and the ambient temperature can be as low as -40℃, the electric drive source heat pump control mode is selected. When the passenger cabin and the battery both issue a heating request in a driving condition, the electric drive electronic control outlet water temperature T3 is less than -20℃, and the ambient temperature can be as low as -40℃, the electric drive waste heat + hot air bypass control mode is selected. When the passenger cabin and the battery both issue a heating request in a parking condition, the vehicle speed is 0 km / h, and the ambient temperature is -20℃ to 15℃, the air source heat pump + PTC control mode is selected. When the passenger cabin issues a heating request and the battery issues a cooling request in a driving condition, the vehicle speed is greater than 0 km / h, and the ambient temperature is 5℃ to 15℃, the battery source heat pump control mode is selected.

9. A computer readable storage medium having stored thereon a computer program, characterized in that: The computer program, when executed by a processor, implements the steps of the pure electric vehicle thermal management multi-source heat pump control method in any one of claims 1 to 7.

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