Method and device for improving low-temperature driving range of electric vehicle

Abstract

The present application relates to a method and device for improving the low-temperature driving range of an electric vehicle, and relates to the technical field of the endurance of electric vehicles. The method includes the following steps: when the vehicle is in a driving state, obtain the battery power and the average battery temperature; based on the battery power and the average battery temperature, the heat pump system reduces the heating energy consumption by means of battery heat recovery or air heat absorption. The present application obtains the battery power and the average battery temperature, and adopts the battery heat recovery method or the air heat absorption method for heating according to the data situation, so as to reduce the heating energy consumption of the vehicle and reduce the battery power consumption, thereby realizing the improvement of the low-temperature driving range.

Description

Technical Field

[0001] This application relates to the technical field of electric vehicle endurance, and particularly to a method and device for improving the low-temperature driving range of an electric vehicle. Background Art

[0002] At the present stage, the electric vehicle industry and technology are developing rapidly. In the case of imperfect charging supporting infrastructure, the driving range of electric vehicles, especially the low-temperature driving range, cannot meet the demand for long-distance driving, which is a technical problem that urgently needs to be solved.

[0003] Different from traditional fuel vehicles, electric vehicles have no engine waste heat that can be utilized and need to consume additional electric energy to heat the passenger compartment and the power battery. Therefore, reasonably and effectively utilizing the heat of each system is crucial for improving the low-temperature driving range of electric vehicles.

[0004] Therefore, a technology for improving the low-temperature driving range of electric vehicles is now provided to meet the current usage requirements. Summary of the Invention

[0005] This application provides a method and device for improving the low-temperature driving range of an electric vehicle, which obtains the battery power and the average battery temperature, and according to the data situation, adopts a battery heat recovery method or an air heat absorption method for heating, so as to reduce the heating energy consumption of the vehicle and reduce the battery power consumption, thereby realizing the improvement of the low-temperature driving range.

[0006] In the first aspect, this application provides a method for improving the low-temperature driving range of an electric vehicle, and the method includes the following steps:

[0007] When the vehicle is in a driving state, obtain the battery power and the average battery temperature;

[0008] Based on the battery power and the average battery temperature, the heat pump system reduces the heating energy consumption through a battery heat recovery method or an air heat absorption method.

[0009] Among them, the battery power and the average battery temperature can use preset sensors to monitor data, so as to obtain data information, or use external devices to monitor the battery power and the average battery temperature, and directly obtain the battery power and the average battery temperature when needed later.

[0010] Specifically, when the technical solution of this application is actually implemented, the specific situation is as follows:

[0011] The first step is to obtain the vehicle driving state, that is, the vehicle is in the READY gear.

[0012] The second step is to collect the battery state of charge SOC and the average battery temperature T Batt , and according to the battery power and the average battery temperature, determine the working mode of using battery heat;

[0013] SOC, State of Charge, that is, the state of charge of the battery.

[0014] Among them, the specific judgment process is as follows:

[0015] First, if the battery charge SOC > a and the average battery temperature T Batt > b, at this time, the battery charge and the average battery temperature are relatively high, and the heat of the battery can be recovered through the new heat pump system;

[0016] Under this working condition, the battery temperature can be guaranteed within a certain range, ensuring that the low-temperature performance of the battery is basically the same as that at room temperature. Moreover, the heat pump system absorbs heat from both the air and the battery at the same time, reducing the energy consumption of air-conditioning heating and increasing the low-temperature cruising range;

[0017] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = b - 5, at this time, the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0018] Second, if the battery charge SOC > a and the average battery temperature T Batt < b, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0019] Third, if the battery charge SOC < a and the average battery temperature T Batt > c, at this time, the battery charge is relatively low and the average battery temperature is relatively high. Since the remaining driving range of the vehicle is relatively low, maintaining too high a battery temperature does not improve the low-temperature cruising range. The heat of the battery can be recovered through the new heat pump system;

[0020] Under this working condition, before the battery runs out of power, the heat pump system can absorb heat from the battery to the maximum extent. Moreover, the heat pump system absorbs heat from both the air and the battery at the same time, reducing the energy consumption of air-conditioning heating and increasing the low-temperature cruising range;

[0021] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = c - 5, at this time, the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0022] Fourth, if the battery charge SOC < a and the average battery temperature T Batt < c, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment;

[0023] Among them, the average battery temperature threshold b > c;

[0024] a can be set to 20%, b can be set to 10 °C, and c can be set to 0 °C.

[0025] It should be noted that in the heat absorption mode from air by the heat pump system, the heat pump system absorbs heat from the air through the outdoor heat exchanger;

[0026] In the heat absorption mode from air and the heat absorption mode from the battery by the heat pump system, the heat pump system first absorbs heat from the air through the outdoor heat exchanger, and then absorbs heat from the coolant of the battery system through the water chiller.

[0027] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption through the battery heat recovery method or the air heat absorption method, the following steps are included:

[0028] If the battery power is greater than the battery power threshold and the average battery temperature is greater than the first battery temperature threshold, the heat pump system heats the passenger compartment through the battery heat recovery method and the air heat absorption method;

[0029] When the average battery temperature is less than the second battery temperature threshold, the heat pump system terminates heating the passenger compartment through the battery heat recovery method and heats the passenger compartment through the air heat absorption method.

[0030] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption through the battery heat recovery method or the air heat absorption method, the following steps are included:

[0031] If the battery power is greater than the battery power threshold and the average battery temperature is less than the first battery temperature threshold, the heat pump system heats the passenger compartment through the air heat absorption method.

[0032] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption through the battery heat recovery method or the air heat absorption method, the following steps are included:

[0033] If the battery power is less than the battery power threshold and the average battery temperature is greater than the third battery temperature threshold, the heat pump system heats the passenger compartment through the battery heat recovery method and the air heat absorption method;

[0034] When the average battery temperature is less than the fourth battery temperature threshold, the heat pump system terminates heating the passenger compartment through the battery heat recovery method and heats the passenger compartment through the air heat absorption method; where

[0035] the values of the first battery temperature threshold, the third battery temperature threshold, and the fourth battery temperature threshold decrease in sequence.

[0036] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption through the battery heat recovery method or the air heat absorption method, the following steps are included:

[0037] If the battery power is less than the battery power threshold and the average battery temperature is less than the third battery temperature threshold, the heat pump system heats the passenger compartment by absorbing heat from the air; wherein,

[0038] The values of the first battery temperature threshold and the third battery temperature threshold decrease in sequence.

[0039] In a second aspect, the present application provides a device for improving the low-temperature cruising range of an electric vehicle. The device includes:

[0040] A data acquisition module, which is used to acquire the battery power and the average battery temperature when the vehicle is in a driving state;

[0041] An energy consumption reduction module, which is used to reduce the heating energy consumption by the battery heat recovery method or the air heat absorption method of the heat pump system based on the battery power and the average battery temperature.

[0042] Among them, the battery power and the average battery temperature can be monitored for data to obtain data information by using a preset sensor, or the battery power and the average battery temperature can be monitored by using an external device. When needed later, the battery power and the average battery temperature can be directly obtained.

[0043] Specifically, when the technical solution of the present application is actually implemented, the specific situation is as follows:

[0044] The first step is to obtain the driving state of the vehicle, that is, the vehicle is in the READY gear.

[0045] The second step is to collect the battery state of charge SOC and the average battery temperature T Batt , and determine the working mode of using the battery heat according to the battery power and the average battery temperature;

[0046] SOC, State of Charge, that is, the state of charge of the battery.

[0047] Among them, the specific judgment process is as follows:

[0048] First, if the battery state of charge SOC > a and the average battery temperature T Batt > b, at this time, the battery power and the average battery temperature are relatively high, and the battery heat can be recovered by the new heat pump system;

[0049] Under this working condition, the battery temperature can be guaranteed within a certain range, ensuring that the low-temperature performance of the battery is basically the same as that at room temperature. Moreover, the heat pump system absorbs heat from both the air and the battery at the same time, reducing the air-conditioning heating energy consumption and improving the low-temperature cruising range;

[0050] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = b - 5, at this time, the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0051] Second, if the state of charge (SOC) of the battery > a and the average battery temperature T Batt < b, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0052] Third, if the state of charge (SOC) of the battery < a and the average battery temperature T Batt > c, at this time, the battery state of charge is relatively low and the average battery temperature is relatively high. Since the remaining driving range of the vehicle is relatively low, maintaining too high a battery temperature does not improve the low-temperature driving range. The heat pump new system can recover the battery heat;

[0053] Under this condition, before the battery runs out of power, the heat pump system can absorb heat from the battery to the maximum extent, and the heat pump system absorbs heat from both the air and the battery at the same time, reducing the air-conditioning heating energy consumption and increasing the low-temperature driving range;

[0054] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = c - 5, at this time the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0055] Fourth, if the state of charge (SOC) of the battery < a and the average battery temperature T Batt < c, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment;

[0056] Among them, the average battery temperature threshold b > c;

[0057] a can be set to 20%, b can be set to 10 °C, and c can be set to 0 °C.

[0058] It should be noted that in the mode where the heat pump system absorbs heat from the air, the heat pump system absorbs heat from the air through the outdoor heat exchanger;

[0059] In the mode where the heat pump system absorbs heat from both the air and the battery, the heat pump system first absorbs heat from the air through the outdoor heat exchanger, and then absorbs heat from the battery system coolant through the water chiller.

[0060] Furthermore, the energy consumption reduction module is further configured to, if the battery state of charge is greater than the battery state of charge threshold and the average battery temperature is greater than the first battery temperature threshold, the heat pump system heats the passenger compartment through the battery heat recovery method and the air heat absorption method;

[0061] The energy consumption reduction module is further configured to, when the average battery temperature is less than the second battery temperature threshold, the heat pump system terminates heating the passenger compartment through the battery heat recovery method and heats the passenger compartment through the air heat absorption method.

[0062] Further, the energy consumption reduction module is further configured to, if the battery power is greater than the battery power threshold and the average battery temperature is less than the first battery temperature threshold, the heat pump system heats the passenger compartment by absorbing heat from the air.

[0063] Further, the energy consumption reduction module is further configured to, if the battery power is less than the battery power threshold and the average battery temperature is greater than the third battery temperature threshold, the heat pump system heats the passenger compartment by means of battery heat recovery and by absorbing heat from the air;

[0064] The energy consumption reduction module is further configured to, when the average battery temperature is less than the fourth battery temperature threshold, the heat pump system terminates heating the passenger compartment by means of battery heat recovery and heats the passenger compartment by absorbing heat from the air; wherein,

[0065] The values of the first battery temperature threshold, the third battery temperature threshold, and the fourth battery temperature threshold decrease in sequence.

[0066] Further, the energy consumption reduction module is further configured to, if the battery power is less than the battery power threshold and the average battery temperature is less than the third battery temperature threshold, the heat pump system heats the passenger compartment by absorbing heat from the air; wherein,

[0067] The values of the first battery temperature threshold and the third battery temperature threshold decrease in sequence.

[0068] The beneficial effects brought by the technical solution provided in this application include:

[0069] This application obtains the battery power and the average battery temperature, and according to the data situation, adopts the battery heat recovery method or the air heat absorption method for heating, so as to reduce the heating energy consumption of the vehicle and reduce the battery power consumption, thereby realizing the improvement of the low-temperature cruising range. Description of the Drawings

[0070] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0071] Figure 1 It is the principle flowchart of the technology for improving the low-temperature cruising range of an electric vehicle provided in the embodiments of this application;

[0072] Figure 2 It is the schematic diagram of electric vehicle thermal management in the technology for improving the low-temperature cruising range of an electric vehicle provided in the embodiments of this application;

[0073] Figure 3Schematic diagram of the heat pump system absorbing heat from the air to heat the passenger compartment in the technology for improving the low - temperature driving range of an electric vehicle provided in the embodiments of the present application;

[0074] Figure 4 Schematic diagram of the heat pump system absorbing heat from the air and the battery to heat the passenger compartment in the technology for improving the low - temperature driving range of an electric vehicle provided in the embodiments of the present application. Detailed implementation manners

[0075] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0076] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0077] The embodiments of the present application provide a method and device for improving the low - temperature driving range of an electric vehicle, which obtain the battery power and the average battery temperature, and adopt a battery heat recovery method or an air heat absorption method for heating according to the data situation, so as to reduce the heating energy consumption of the vehicle and reduce the battery power consumption, thereby realizing the improvement of the low - temperature driving range.

[0078] To achieve the above - mentioned technical effects, the general idea of the present application is as follows:

[0079] A method for improving the low - temperature driving range of an electric vehicle, the method comprising the following steps:

[0080] S1. When the vehicle is in a driving state, obtain the battery power and the average battery temperature;

[0081] S2. Based on the battery power and the average battery temperature, the heat pump system reduces the heating energy consumption through a battery heat recovery method or an air heat absorption method.

[0082] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0083] In a first aspect, as shown in Figures 1 to 4 A method for improving the low - temperature driving range of an electric vehicle is provided in the embodiments of the present application, the method comprising the following steps:

[0084] S1. When the vehicle is in a driving state, obtain the battery power and the average battery temperature;

[0085] S2. Based on the battery power and the average battery temperature, the heat pump system reduces the heating energy consumption through the battery heat recovery method or the air heat absorption method.

[0086] Among them, the battery power and the average battery temperature can be monitored for data through preset sensors to obtain data information, or external devices can be used to monitor the battery power and the average battery temperature. When needed later, the battery power and the average battery temperature can be directly obtained.

[0087] It should be noted that in the case where the charging supporting infrastructure is not perfect, the driving range of electric vehicles, especially the low-temperature driving range, cannot meet the long-distance driving requirements, which has always been a focus of people's complaints.

[0088] Different from traditional fuel vehicles, electric vehicles have no engine waste heat that can be utilized and need to consume additional electric energy to heat the passenger compartment and the power battery.

[0089] Therefore, reasonably and effectively utilizing the heat of each system is an effective measure to improve the low-temperature driving range of electric vehicles. As a large-capacity heat storage device with a large mass, the battery has less research on the utilization of its heat in a low-temperature environment.

[0090] In a low-temperature environment, after driving for a long distance for a period of time, due to the active heating and self-heating of the battery, the battery temperature can reach 10 - 30 °C;

[0091] At this time, the low-temperature performance of the battery can be basically the same as that at normal temperature. The excessive battery temperature can be recovered by the heat pump system to heat the passenger compartment. Continuing to drive, when the battery is at a low SOC, due to the low remaining driving range, the heat pump system can further recover the battery heat to heat the passenger compartment;

[0092] Moreover, the battery temperature is much higher than the ambient temperature, and its energy quality is higher than the ambient temperature, which can significantly reduce the air-conditioning heating energy consumption and improve the low-temperature driving range.

[0093] In the embodiments of the present application, the battery power and the average battery temperature are obtained, and according to the data situation, the battery heat recovery method or the air heat absorption method is adopted for heating to reduce the heating energy consumption of the vehicle and reduce the battery power consumption, thereby realizing the improvement of the low-temperature driving range.

[0094] Specifically, in the process that the heat pump system reduces the heating energy consumption through the battery heat recovery method or the air heat absorption method based on the battery power and the average battery temperature, the following steps are included:

[0095] If the battery power is greater than the battery power threshold and the average battery temperature is greater than the first battery temperature threshold, the heat pump system heats the passenger compartment through the battery heat recovery method and the air heat absorption method;

[0096] When the average battery temperature is less than the second battery temperature threshold, the heat pump system terminates heating the occupant compartment by recovering battery heat and heats the occupant compartment by absorbing heat from the air.

[0097] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption by recovering battery heat or absorbing heat from the air, the following steps are included:

[0098] If the battery power is greater than the battery power threshold and the average battery temperature is less than the first battery temperature threshold, the heat pump system heats the occupant compartment by absorbing heat from the air.

[0099] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption by recovering battery heat or absorbing heat from the air, the following steps are included:

[0100] If the battery power is less than the battery power threshold and the average battery temperature is greater than the third battery temperature threshold, the heat pump system heats the occupant compartment by recovering battery heat and absorbing heat from the air;

[0101] When the average battery temperature is less than the fourth battery temperature threshold, the heat pump system terminates heating the occupant compartment by recovering battery heat and heats the occupant compartment by absorbing heat from the air; wherein,

[0102] The values of the first battery temperature threshold, the third battery temperature threshold, and the fourth battery temperature threshold decrease in sequence.

[0103] Specifically, based on the battery power and the average battery temperature, when the heat pump system reduces the heating energy consumption by recovering battery heat or absorbing heat from the air, the following steps are included:

[0104] If the battery power is less than the battery power threshold and the average battery temperature is less than the third battery temperature threshold, the heat pump system heats the occupant compartment by absorbing heat from the air; wherein,

[0105] The values of the first battery temperature threshold and the third battery temperature threshold decrease in sequence.

[0106] Based on the technical solution of the embodiment of the present application, the specific implementation is as follows:

[0107] The first step is to obtain the vehicle driving state, that is, the vehicle is in the READY gear.

[0108] The second step is to collect the battery state of charge SOC and the average battery temperature T Batt , and determine the working mode of using the battery heat according to the battery power and the average battery temperature;

[0109] SOC, State of Charge, refers to the state of charge of the battery.

[0110] Among them, the specific judgment process is as follows:

[0111] First, if the battery state of charge SOC > a and the average battery temperature T Batt > b, at this time, the battery state of charge and the average battery temperature are relatively high, and the heat of the battery can be recovered through the new heat pump system;

[0112] Under this working condition, the battery temperature can be guaranteed within a certain range, ensuring that the low-temperature performance of the battery is basically the same as that at normal temperature. Moreover, the heat pump system absorbs heat from both the air and the battery simultaneously, reducing the energy consumption of air-conditioning heating and increasing the low-temperature cruising range;

[0113] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = b - 5, at this time, the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0114] Second, if the battery state of charge SOC > a and the average battery temperature T Batt < b, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0115] Third, if the battery state of charge SOC < a and the average battery temperature T Batt > c, at this time, the battery state of charge is relatively low and the average battery temperature is relatively high. Since the remaining cruising range of the vehicle is relatively low, maintaining too high a battery temperature does not improve the low-temperature cruising range. The heat of the battery can be recovered through the new heat pump system;

[0116] Under this working condition, before the battery runs out of power, the heat pump system can absorb heat from the battery to the maximum extent. Moreover, the heat pump system absorbs heat from both the air and the battery simultaneously, reducing the energy consumption of air-conditioning heating and increasing the low-temperature cruising range;

[0117] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = c - 5, at this time, the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0118] Fourth, if the battery state of charge SOC < a and the average battery temperature T Batt < c, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment;

[0119] Among them, the average battery temperature threshold b > c;

[0120] a can be set to 20%, b can be set to 10°C, and c can be set to 0°C.

[0121] It should be noted that in the heat absorption mode from air by the heat pump system, the heat pump system absorbs heat from the air through the outdoor heat exchanger.

[0122] In the heat absorption mode from air and battery by the heat pump system, the heat pump system first absorbs heat from the air through the outdoor heat exchanger, and then absorbs heat from the coolant of the battery system through the water chiller.

[0123] In addition, the schematic diagram of the electric vehicle thermal management is as shown in Figure 2 the schematic diagram of the heat pump system absorbing heat from air to heat the occupant compartment is as shown in Figure 3 the schematic diagram of the heat pump system absorbing heat from air and battery to heat the occupant compartment is as shown in Figure 4 the attached drawings of the specification.

[0124] It should be noted that as shown in Figure 1 the attached drawings of the specification, a is the battery power threshold, b is the first battery temperature threshold, b - 5 is the second battery temperature threshold, c is the third battery temperature threshold, and c - 5 is the fourth battery temperature threshold.

[0125] In a second aspect, referring to Figures 1 to 4 as shown, based on the technical basis of the method for improving the low - temperature cruising range of an electric vehicle mentioned in the first aspect of the embodiments of the present application, a device for improving the low - temperature cruising range of an electric vehicle is provided. The device includes:

[0126] A data acquisition module, which is used to acquire the battery power and the average battery temperature when the vehicle is in a driving state.

[0127] An energy consumption reduction module, which is used to reduce the heating energy consumption through the battery heat recovery method or the air heat absorption method by the heat pump system based on the battery power and the average battery temperature.

[0128] Among them, the battery power and the average battery temperature can be monitored for data through preset sensors to obtain data information, or external devices can be used to monitor the battery power and the average battery temperature. When needed later, the battery power and the average battery temperature can be directly obtained.

[0129] It should be noted that in the case where the charging supporting infrastructure is not perfect, the cruising range of electric vehicles, especially the low - temperature cruising range, cannot meet the long - distance driving requirements, which has always been a focus of people's complaints.

[0130] Different from traditional fuel vehicles, electric vehicles have no engine waste heat that can be utilized and need to consume additional electric energy to heat the occupant compartment and the power battery.

[0131] Therefore, making reasonable and effective use of the heat of each system is an effective measure to improve the low-temperature driving range of electric vehicles. However, as an energy storage device with a large heat capacity and a large mass, the battery has received less research on heat utilization in low-temperature environments.

[0132] In a low-temperature environment, after driving for a long distance for some time, due to the active heating and self-heating of the battery, the battery temperature can reach 10 - 30°C.

[0133] At this time, the low-temperature performance of the battery can basically be the same as that at room temperature. The excessive battery temperature can be recovered by the heat pump system to heat the passenger compartment. Continuing to drive, when the battery is at a low state of charge (SOC), due to the relatively low remaining driving range, the heat of the battery can be further recovered by the heat pump system to heat the passenger compartment.

[0134] Moreover, the battery temperature is much higher than the ambient temperature, and its energy quality is higher than that of the ambient temperature, which can significantly reduce the energy consumption of air conditioning heating and improve the low-temperature driving range.

[0135] In the embodiments of the present application, the battery power and the average battery temperature are obtained, and according to the data situation, a battery heat recovery method or an air heat absorption method is adopted for heating to reduce the heating energy consumption of the vehicle and reduce the battery power consumption, thereby realizing the improvement of the low-temperature driving range.

[0136] Furthermore, the energy consumption reduction module is further configured to, if the battery power is greater than the battery power threshold and the average battery temperature is greater than the first battery temperature threshold, the heat pump system heats the passenger compartment through the battery heat recovery method and the air heat absorption method.

[0137] The energy consumption reduction module is further configured to, when the average battery temperature is less than the second battery temperature threshold, the heat pump system terminates heating the passenger compartment through the battery heat recovery method and heats the passenger compartment through the air heat absorption method.

[0138] Furthermore, the energy consumption reduction module is further configured to, if the battery power is greater than the battery power threshold and the average battery temperature is less than the first battery temperature threshold, the heat pump system heats the passenger compartment through the air heat absorption method.

[0139] Furthermore, the energy consumption reduction module is further configured to, if the battery power is less than the battery power threshold and the average battery temperature is greater than the third battery temperature threshold, the heat pump system heats the passenger compartment through the battery heat recovery method and the air heat absorption method.

[0140] The energy consumption reduction module is further configured to, when the average battery temperature is less than the fourth battery temperature threshold, the heat pump system terminates heating the passenger compartment through the battery heat recovery method and heats the passenger compartment through the air heat absorption method; where

[0141] The values of the first battery temperature threshold, the third battery temperature threshold, and the fourth battery temperature threshold decrease in sequence.

[0142] Further, the energy consumption reduction module is further configured to, if the battery power is less than the battery power threshold and the average battery temperature is less than the third battery temperature threshold, the heat pump system heats the occupant compartment by absorbing heat from the air; wherein,

[0143] The values of the first battery temperature threshold and the third battery temperature threshold decrease in sequence.

[0144] Based on the technical solution of the embodiment of the present application, the specific implementation is as follows:

[0145] First step, obtain the vehicle driving state, that is, the vehicle is in the READY gear.

[0146] Second step, collect the battery state of charge SOC and the average battery temperature T Batt , and determine the working mode of using the battery heat according to the battery power and the average battery temperature.

[0147] Among them, the specific judgment process is as follows:

[0148] First, if the battery state of charge SOC > a, and the average battery temperature T Batt > b, at this time, the battery power and the average battery temperature are relatively high, and the battery heat can be recovered through the new heat pump system;

[0149] In this working condition, the battery temperature can be guaranteed within a certain range, ensuring that the low-temperature performance of the battery is basically the same as that at room temperature. Moreover, the heat pump system absorbs heat from both the air and the battery at the same time, reducing the air-conditioning heating energy consumption and increasing the low-temperature cruising range;

[0150] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = b - 5, at this time, the heat pump system only absorbs heat from the air to heat the occupant compartment.

[0151] Second, if the battery state of charge SOC > a, and the average battery temperature T Batt < b, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the occupant compartment.

[0152] Third, if the battery state of charge SOC < a, and the average battery temperature T Batt > c, at this time, the battery power is relatively low and the average battery temperature is relatively high. Since the remaining driving mileage of the vehicle is relatively low, maintaining too high a battery temperature does not improve the low-temperature cruising range. The battery heat can be recovered through the new heat pump system;

[0153] Under this condition, before the battery runs out of power, the heat pump system can absorb heat from the battery to the maximum extent. Moreover, the heat pump system absorbs heat from both the air and the battery simultaneously, reducing the energy consumption of air-conditioning heating and increasing the low-temperature cruising range.

[0154] The heat pump continuously absorbs heat from the battery until the average battery temperature T Batt = c - 5. At this time, the heat pump system only absorbs heat from the air to heat the passenger compartment.

[0155] Fourth, if the battery state of charge SOC < a and the average battery temperature T Batt < c, at this time, the battery temperature is relatively low, and the heat pump system only absorbs heat from the air to heat the passenger compartment;

[0156] Among them, the average battery temperature threshold b > c;

[0157] a can be set to 20%, b can be set to 10 °C, and c can be set to 0 °C.

[0158] It should be noted that in the mode where the heat pump system absorbs heat from the air, the heat pump system absorbs heat from the air through the outdoor heat exchanger;

[0159] In the mode where the heat pump system absorbs heat from both the air and the battery, the heat pump system first absorbs heat from the air through the outdoor heat exchanger, and then absorbs heat from the coolant of the battery system through the water chiller.

[0160] In addition, the schematic diagram of the electric vehicle thermal management is as shown in the Figure 2 schematic diagram of the heat pump system absorbing heat from the air to heat the passenger compartment is as shown in the Figure 3 schematic diagram of the heat pump system absorbing heat from both the air and the battery to heat the passenger compartment is as shown in the Figure 4 schematic diagram.

[0161] It should be noted that as shown in the Figure 1 schematic diagram in the specification drawings, a is the battery state of charge threshold, b is the first battery temperature threshold, b - 5 is the second battery temperature threshold, c is the third battery temperature threshold, and c - 5 is the fourth battery temperature threshold.

[0162] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0163] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for improving the low - temperature driving range of an electric vehicle, characterized in that, the method comprises the following steps: When the vehicle is in a driving state, obtain the battery power and the average battery temperature; Based on the battery power and the average battery temperature, the heat pump system reduces the heating energy consumption by means of battery heat recovery or air heat absorption; In the process that the heat pump system reduces the heating energy consumption by means of battery heat recovery or air heat absorption based on the battery power and the average battery temperature, the following steps are included: If the battery power is greater than the battery power threshold and the average battery temperature is greater than the first battery temperature threshold, the heat pump system heats the passenger compartment by means of battery heat recovery and air heat absorption; When the average battery temperature is less than the second battery temperature threshold, the heat pump system terminates heating the passenger compartment by means of battery heat recovery and heats the passenger compartment by means of air heat absorption; In the process that the heat pump system reduces the heating energy consumption by means of battery heat recovery or air heat absorption based on the battery power and the average battery temperature, the following steps are included: If the battery power is less than the battery power threshold and the average battery temperature is greater than the third battery temperature threshold, the heat pump system heats the passenger compartment by means of battery heat recovery and air heat absorption; When the average battery temperature is less than the fourth battery temperature threshold, the heat pump system terminates heating the passenger compartment by means of battery heat recovery and heats the passenger compartment by means of air heat absorption; If the battery power is less than the battery power threshold and the average battery temperature is less than the third battery temperature threshold, the heat pump system heats the passenger compartment by means of air heat absorption; In the process that the heat pump system reduces the heating energy consumption by means of battery heat recovery or air heat absorption based on the battery power and the average battery temperature, the following steps are included: If the battery power is greater than the battery power threshold and the average battery temperature is less than the first battery temperature threshold, the heat pump system heats the passenger compartment by means of air heat absorption; wherein, the values of the first battery temperature threshold, the third battery temperature threshold and the fourth battery temperature threshold decrease in sequence.

2. A device for improving the low - temperature driving range of an electric vehicle, characterized in that, the device comprises: A data acquisition module, which is used to obtain the battery power and the average battery temperature when the vehicle is in a driving state; An energy consumption reduction module, which is used to reduce the heating energy consumption of the heat pump system by means of battery heat recovery or air heat absorption based on the battery power and the average battery temperature; The energy consumption reduction module is further used for if the battery power is greater than the battery power threshold and the average battery temperature is greater than the first battery temperature threshold, the heat pump system heats the passenger compartment by means of battery heat recovery and air heat absorption; The energy consumption reduction module is further used for when the average battery temperature is less than the second battery temperature threshold, the heat pump system terminates heating the passenger compartment by means of battery heat recovery and heats the passenger compartment by means of air heat absorption; The energy consumption reduction module is further configured to, if the battery power is less than the battery power threshold and the average battery temperature is greater than the third battery temperature threshold, heat the occupant compartment of the heat pump system through the battery heat recovery method and the air heat absorption method; The energy consumption reduction module is further configured to, when the average battery temperature is less than the fourth battery temperature threshold, the heat pump system terminates heating the occupant compartment through the battery heat recovery method and heats the occupant compartment through the air heat absorption method; The energy consumption reduction module is further configured to, if the battery power is less than the battery power threshold and the average battery temperature is less than the third battery temperature threshold, heat the occupant compartment of the heat pump system through the air heat absorption method; The energy consumption reduction module is further configured to, if the battery power is greater than the battery power threshold and the average battery temperature is less than the first battery temperature threshold, heat the occupant compartment of the heat pump system through the air heat absorption method; wherein, The values of the first battery temperature threshold, the third battery temperature threshold, and the fourth battery temperature threshold decrease in sequence.

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