Motor winding-based battery pack heating method, apparatus, and device, and storage medium

Abstract

The present application relates to the technical field of battery thermal management, and discloses a motor winding-based battery pack heating method, apparatus, and device, and a storage medium. Disclosed is a motor winding-based battery pack heating method, comprising: detecting a rotor temperature by means of a rotor operating state temperature model; upon receiving a heating instruction, separately turning on at least two of bridge arm switches of a first phase, a second phase and a third phase of a power device on the basis of the rotor temperature and a switch-on strategy, so as to perform winding heating between different phases; transferring, to a battery pack, heat generated during the heating of the windings; and stopping the heating of the windings on the basis of a temperature protection strategy, so as to complete heating of the battery pack.

Description

Battery pack heating method, apparatus, equipment, and storage medium based on motor windings

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 202411453351.8, filed with the Chinese Patent Office on October 17, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery thermal management technology, and in particular to battery pack heating methods, apparatus, equipment and storage media based on motor windings. Background Technology

[0004] The performance of power batteries in new energy vehicles is sensitive to temperature, with optimal performance occurring between 15℃ and 35℃. Therefore, the power battery thermal management system must constantly control the battery temperature within a suitable range to maximize battery performance. Traditional battery pack heating designs aim to ensure the battery pack operates in a suitable temperature environment to achieve maximum driving range. This typically involves using a dedicated electric PTC heater to generate heat on the battery pack surface, or using heat from a heat pump air conditioner to transfer heat to the battery pack via cooling water in water channels.

[0005] However, using PTC heaters increases costs and may pose a safety risk of overheating. Heat pump air conditioning systems become less efficient in cold environments and require additional cooling modes to transfer heat. Using a stalled motor for heating can damage the motor and lacks precise control.

[0006] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0007] The main objective of this application is to provide a battery pack heating method, apparatus, device, and storage medium based on motor windings, aiming to solve the technical problem of how to efficiently and accurately preheat battery packs using existing motor windings without increasing additional costs.

[0008] To achieve the above objectives, this application proposes a battery pack heating method based on motor windings, the method comprising:

[0009] Rotor temperature is detected using a rotor operating state temperature model;

[0010] Upon receiving a heating command, at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment are opened according to the rotor temperature and the opening strategy to heat the windings between different phases.

[0011] The heat generated when the winding is heated is transferred to the battery pack;

[0012] According to the temperature protection strategy, the heating of the winding is stopped, and the battery pack heating is completed.

[0013] In one embodiment, the step of opening at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment respectively according to the rotor temperature and the opening strategy when a heating command is received, to perform winding heating between different phases, includes:

[0014] Upon receiving a heating command, the tube opening time period is obtained based on the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, the temperature of the negative temperature coefficient thermistor, the current temperature of the battery pack, the proportional-integral-derivative control strategy, and the tube opening heating strategy.

[0015] By opening at least two of the following switches according to the opening strategy and the opening time period: the first upper bridge arm switch of the first phase, the first lower bridge arm switch of the first phase, the second upper bridge arm switch of the second phase, the second lower bridge arm switch of the second phase, the third upper bridge arm switch of the third phase, and the third lower bridge arm switch of the third phase, winding heating between different phases is completed.

[0016] In one embodiment, the step of obtaining the tube-opening time period upon receiving a heating command, based on the rotor temperature, the insulated gate bipolar transistor temperatures of the upper and lower bridge arm switches, the negative temperature coefficient thermistor temperature, the current battery pack temperature, the proportional-integral-derivative control strategy, and the tube-opening heating strategy, includes:

[0017] Upon receiving a heating command, the rotor temperature control signal, the insulated gate bipolar transistor temperature of the upper and lower bridge arm switches, the negative temperature coefficient thermistor temperature, the current battery pack temperature, and the proportional-integral-derivative control strategy are used to obtain the following control signals: rotor temperature control signal, insulated gate bipolar transistor temperature control signal, negative temperature coefficient thermistor temperature control signal, and current battery pack temperature control signal.

[0018] The target control signal is obtained based on the rotor temperature control signal, the insulated gate bipolar transistor temperature control signal, the negative temperature coefficient thermistor temperature control signal, and the current temperature control signal of the battery pack.

[0019] The opening time period is obtained based on the target control signal and the opening heating strategy.

[0020] In one embodiment, the step of opening at least two of the following components—the first upper bridge arm switch of the first phase, the first lower bridge arm switch of the first phase, the second upper bridge arm switch of the second phase, the second lower bridge arm switch of the second phase, the third upper bridge arm switch of the third phase, and the third lower bridge arm switch of the third phase—to complete winding heating between different phases via an opening strategy and the opening time period includes:

[0021] The first upper arm switch and the second lower arm switch of the power equipment are opened by the pipe opening strategy, and the first lower arm switch, the second upper arm switch, the third upper arm switch and the third lower arm switch are closed.

[0022] During the period of pipe opening, the first upper bridge arm switch and the second lower bridge arm switch are closed, and the first lower bridge arm switch and the second upper bridge arm switch are opened.

[0023] During the period of pipe opening, the first lower bridge arm switch and the second upper bridge arm switch are closed, and the second upper bridge arm switch and the third lower bridge arm switch are opened.

[0024] During the specified opening period, the second upper bridge arm switch and the third lower bridge arm switch are closed, and the second lower bridge arm switch and the third upper bridge arm switch are opened.

[0025] During the period of time when the pipe is opened, the second lower bridge arm switch and the third upper bridge arm switch are closed, and the third upper bridge arm switch and the first lower bridge arm switch are opened.

[0026] During the opening period, the third upper bridge arm switch and the first lower bridge arm switch are closed, and the third lower bridge arm switch and the first upper bridge arm switch are opened to complete the winding heating between different phases.

[0027] In one embodiment, the step of detecting the rotor temperature using a rotor operating state temperature model includes:

[0028] Obtain the overall power loss;

[0029] A rotor operating temperature model is established based on the comprehensive power loss.

[0030] The rotor temperature is obtained based on the rotor operating state temperature model.

[0031] In one embodiment, the step of obtaining the total power loss includes:

[0032] The power loss of the coolant, the power loss of the stator to the environment, the power loss of the rotor and magnets to the environment, and the heat loss of the rotor are obtained.

[0033] The comprehensive power loss is obtained based on the stator power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, and the rotor heat loss.

[0034] In one embodiment, the step of obtaining the coolant power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, and the rotor heat loss includes:

[0035] The power loss of the coolant is obtained based on the coolant density, the cross-sectional area of ​​the cooling pipe, the coolant flow velocity, the inlet water temperature, and the outlet water temperature.

[0036] The power loss of the stator to the environment is obtained based on the stator surface convective heat transfer area, stator surface temperature, ambient temperature and preset convective heat transfer coefficient.

[0037] Based on the convective heat transfer area of ​​the rotor surface, the rotor temperature at the first moment, and the preset convective heat transfer coefficient, the power dissipation loss of the rotor and magnets to the environment is obtained.

[0038] The rotor heat loss is obtained based on the specific heat capacity of the rotor material, the rotor mass, the rotor temperature at the second moment, and the rotor temperature at the third moment.

[0039] In one embodiment, the step of establishing a rotor operating temperature model based on the comprehensive power loss includes:

[0040] Obtain the specific heat capacity of the stator material, the stator mass, the stator temperature at the first moment, and the stator temperature at the second moment;

[0041] A rotor operating temperature model is established based on the specific heat capacity of the stator material, the stator mass, the stator temperature at the first moment, the stator temperature at the second moment, and the comprehensive power loss.

[0042] In one embodiment, the step of stopping the winding heating and completing the battery pack heating according to the temperature protection strategy includes:

[0043] A first preset temperature and a second preset temperature are obtained according to a temperature protection strategy, wherein the first preset temperature is greater than the second preset temperature.

[0044] When any one of the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, or the temperature of the negative temperature coefficient thermistor is greater than the first preset temperature, or when the current temperature of the battery pack is greater than the second preset temperature, the winding heating is stopped, and the battery pack heating is completed.

[0045] Furthermore, to achieve the above objectives, this application also proposes a battery pack heating device based on motor windings, the battery pack heating device based on motor windings comprising:

[0046] The detection module is used to detect rotor temperature using a rotor operating state temperature model.

[0047] The heating module is used to open at least two of the bridge arm switches of the first phase, the second phase, and the third phase of the power equipment respectively according to the rotor temperature and the opening strategy when a heating command is received, so as to heat the windings between different phases.

[0048] A heat transfer module is used to transfer the heat generated when the winding is heated to the battery pack;

[0049] The stop module is used to stop the heating of the winding according to the temperature protection strategy, thereby completing the heating of the battery pack.

[0050] In addition, to achieve the above objectives, this application also proposes a battery pack heating device based on motor windings, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the battery pack heating method based on motor windings as described above.

[0051] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the battery pack heating method based on motor windings as described above.

[0052] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the battery pack heating method based on motor windings as described above.

[0053] One or more technical solutions proposed in this application have at least the following technical effects:

[0054] By employing a rotor operating temperature model to detect rotor temperature; upon receiving a heating command, opening at least two of the bridge arm switches for the first, second, and third phases of the power unit according to the rotor temperature and the opening strategy to heat the windings between different phases; transferring the heat generated during winding heating to the battery pack; and stopping winding heating according to a temperature protection strategy to complete battery pack heating, this approach solves the problem of effectively preheating the battery pack without increasing additional hardware costs, achieving a rapid and safe battery preheating effect. Compared with existing technologies, this solution optimizes heating efficiency, improves temperature control accuracy, avoids potential damage to the motor and battery, and enhances the performance and driving range of electric vehicles in low-temperature environments. Attached Figure Description

[0055] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0056] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 is a schematic flowchart of the battery pack heating method based on motor windings provided in Embodiment 1 of this application;

[0058] Figure 2 is a schematic diagram of the heating command sending logic provided in Embodiment 1 of the battery pack heating method based on motor windings in this application;

[0059] Figure 3 is a schematic diagram of the electric drive system architecture provided in Embodiment 1 of the battery pack heating method based on motor windings in this application;

[0060] Figure 4 is a schematic flowchart of the battery pack heating method based on motor windings provided in Embodiment 2 of this application;

[0061] Figure 5 is a block diagram of the powertrain control system provided in Embodiment 2 of the battery pack heating method based on motor windings of this application;

[0062] Figure 6 is a schematic flowchart of the battery pack heating method based on motor windings provided in Embodiment 3 of this application;

[0063] Figure 7 is a schematic diagram of the module structure of the battery pack heating device based on the motor winding in an embodiment of this application;

[0064] Figure 8 is a schematic diagram of the hardware operating environment of the battery pack heating method based on motor windings in the embodiments of this application.

[0065] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0066] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0067] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0068] The main solution in this application embodiment is: to detect rotor temperature through a rotor operating state temperature model;

[0069] Upon receiving a heating command, at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment are opened according to the rotor temperature and the opening strategy to heat the windings between different phases.

[0070] The heat generated when the winding is heated is transferred to the battery pack;

[0071] According to the temperature protection strategy, the heating of the winding is stopped, and the battery pack heating is completed.

[0072] In this embodiment, for ease of description, the following description will focus on identifying the motor controller as the execution subject.

[0073] Since existing technologies cannot efficiently and accurately preheat battery packs using existing motor windings without increasing additional costs, this application provides a solution that employs a rotor operating temperature model to detect rotor temperature; upon receiving a heating command, at least two of the bridge arm switches for the first, second, and third phases of the power unit are opened according to the rotor temperature and an opening strategy to heat the windings between different phases; the heat generated during winding heating is transferred to the battery pack; and the winding heating is stopped according to a temperature protection strategy, thus completing battery pack heating. This solution solves the problem of effectively preheating the battery pack without increasing additional hardware costs, achieving a fast and safe battery preheating effect. Compared with existing technologies, this solution optimizes heating efficiency, improves temperature control accuracy, avoids potential damage to the motor and battery, and enhances the performance and driving range of electric vehicles in low-temperature environments.

[0074] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone; or an electronic device capable of performing the above functions, a battery pack heating device based on motor windings, or a motor controller. The following description uses a motor controller as an example to illustrate this embodiment and the subsequent embodiments.

[0075] Based on this, this application provides a battery pack heating method based on motor windings. Referring to Figure 1, Figure 1 is a flowchart of the first embodiment of the battery pack heating method based on motor windings of this application.

[0076] In this embodiment, the battery pack heating method based on motor windings includes steps S10 to S40:

[0077] Step S10: Detect the rotor temperature using the rotor operating state temperature model;

[0078] It should be noted that the rotor operating temperature model is a mathematical model used to describe the temperature changes of the rotor during operation. This model needs to consider factors such as motor load, ambient temperature, and rotor physical characteristics. The rotor temperature can be monitored in real time through the model, facilitating its use in subsequent steps.

[0079] Additionally, it should be noted that in the powertrain system of new energy vehicles, the Motor Control Unit (MCU) is a key component used to control the operation of the motor. It is mainly responsible for receiving instructions from the vehicle controller (VCU) or other control units and precisely controlling the torque and speed of the motor to realize operations such as vehicle starting, acceleration, deceleration and braking.

[0080] In one feasible implementation, step S10 may include steps S11 to S13:

[0081] Step S11: Obtain the overall power loss;

[0082] Total power loss refers to the power loss generated by multiple components such as coolant, stator, rotor and magnets during motor operation.

[0083] Comprehensive power loss measures the total energy loss of a motor during operation due to various factors. Comprehensive power loss includes coolant power loss, stator power dissipation to the environment, rotor and magnet power dissipation to the environment, and rotor heat loss. Coolant power loss refers to the heat absorbed by the coolant as it flows through the motor stator, which is related to the heat generated by the stator. Stator power dissipation to the environment involves the heat released by the stator and its windings to the environment through conduction, convection, and radiation. Rotor and magnet power dissipation to the environment focuses on the heat released by the rotor and magnets to the environment through heat exchange mechanisms. Rotor heat loss refers to the heat generated by the rotor over a certain period due to its material properties and temperature changes.

[0084] In one feasible implementation, step S11 may include steps S111 to S112:

[0085] Step S111: Obtain the coolant power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, and the rotor heat loss.

[0086] It should be noted that coolant power loss is the stator power loss absorbed by the coolant, representing the heat absorbed by the coolant during its circulation within the motor, which is usually related to the heat generated by the stator. Stator power dissipation to the environment includes the power dissipation of the stator and its windings to the environment, representing the heat released by the stator to the environment through heat conduction, convection, and radiation. Rotor and magnet power dissipation to the environment refers to the power dissipation of the rotor and magnets to the surrounding environment, representing the heat released by the rotor and magnets to the environment through similar heat exchange mechanisms. Rotor heat loss represents the heat generated by the rotor over a certain period of time, which can be obtained using a rotor heat loss temperature model.

[0087] Step S112: The comprehensive power loss is obtained based on the stator power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, and the rotor heat loss.

[0088] The overall power loss in the motor system is determined based on the acquired power loss parameters. This determination involves analyzing and evaluating the impact of each parameter to understand and describe the total heat loss of the motor during operation. The assessment of stator power loss considers the resistance of the stator material and the heat generated when current flows through it. The stator's power dissipation to the environment reflects the efficiency of heat transfer from the stator to the surrounding environment, which is typically related to the stator's design and operating environment. The rotor and magnet power dissipation to the environment focuses on the heat release from the rotor and magnets. The calculation of rotor heat loss is based on the thermal characteristics of the rotor material and operating conditions, such as the rotor's specific heat capacity, mass, and temperature changes.

[0089] In one feasible implementation, step S112 may include steps S1121 to S1124:

[0090] Step S1121: Based on the coolant density, cooling pipe cross-sectional area, coolant flow velocity, inlet water temperature, and outlet water temperature, the coolant power loss is obtained.

[0091] It should be noted that coolant density refers to the mass of coolant per unit volume, which affects the coolant's heat capacity and heat transfer efficiency. Coolant pipe cross-sectional area, or the cross-sectional area of ​​the cooling pipes, refers to the area of ​​the cross-section through which the coolant flows, determining the coolant's flow rate and velocity. Coolant flow velocity refers to the speed at which the coolant flows in the pipes, affecting the efficiency of heat exchange between the coolant and the pipe walls. Inlet water temperature refers to the temperature of the coolant entering the motor cooling system, expressed in degrees Celsius (°C) or Kelvin (K). Outlet water temperature refers to the temperature of the coolant leaving the motor cooling system, also expressed in degrees Celsius (°C) or Kelvin (K).

[0092] The formula for calculating coolant power loss, i.e., stator power loss absorbed by the coolant, is as follows: Pω =ρ ω C ω A ω υ(T in -T out (Equation 1)

[0093] In the formula, ρ ω C is the density of the coolant. ω For the specific heat capacity of the coolant, A ω Where T is the cross-sectional area of ​​the cooling pipe, υ is the flow velocity of the coolant, and T is the cross-sectional area of ​​the cooling pipe. in and T out These are the inlet and outlet water temperatures, P ω Stator power loss absorbed by the coolant.

[0094] Step S1122: Based on the stator surface convective heat transfer area, stator surface temperature, ambient temperature, and preset convective heat transfer coefficient, the power loss of the stator to the environment is obtained.

[0095] It should be noted that the stator surface convective heat transfer area refers to the area of ​​the stator surface that participates in convective heat transfer. This area determines the heat transfer efficiency; the larger the area, the stronger the heat dissipation capacity. The stator surface temperature refers to the temperature of the motor stator during operation, usually expressed in degrees Celsius (°C) or Kelvin (K). This temperature reflects the thermal state of the stator. The ambient temperature refers to the temperature of the environment surrounding the motor, also expressed in degrees Celsius (°C) or Kelvin (K). This temperature serves as a reference for heat dissipation. The convective heat transfer coefficient is a parameter describing the efficiency of heat exchange between a fluid, such as air or coolant, and a solid surface. It depends on the fluid properties, flow velocity, and flow state.

[0096] The formula for calculating the power dissipation loss of the stator to the environment, that is, the power dissipation loss of the stator and its windings to the surrounding environment, is as follows: Equation 2:

[0097] In the formula, σ is the convective heat transfer coefficient, and A s T represents the convective heat transfer area of ​​the stator and winding surfaces. s T1 represents the surface temperature of the stator and windings, and T0 represents the ambient temperature. Both are constants or obtained through sampling by the controller. T1 and T2 are the start and end times of a unit of time, respectively, calculated by the timing of two PWM waveforms.

[0098] In this embodiment, the convective heat transfer coefficient can be calculated using the empirical formula as shown in Equation 3: σ=9.73+14V 0.62 (Equation 3)

[0099] In the formula, σ is the convective heat transfer coefficient, and V is the air velocity on the heat dissipation surface. When the rotor is stationary, σ = 9.73.

[0100] Step S1123: Based on the convective heat transfer area of ​​the rotor surface, the rotor temperature at the first moment, and the preset convective heat transfer coefficient, the power dissipation loss of the rotor and magnets to the environment is obtained.

[0101] It should be noted that the rotor surface convective heat transfer area refers to the area of ​​the rotor surface that participates in convective heat transfer. This area is the actual region where heat exchange occurs and has a direct impact on heat dissipation efficiency. The rotor temperature at the first moment is the rotor temperature measured at a specific point in time (the first moment), usually expressed in degrees Celsius (°C) or Kelvin (K). This temperature is the starting point for heat exchange calculations.

[0102] The power dissipation loss of the rotor and magnets to the environment is calculated using the following formula (Equation 4):

[0103] In the formula, σ is the convective heat transfer coefficient, which is 9.73 in this formula, A r T is the convective heat transfer area of ​​the rotor surface. r1 Let t1 be the rotor temperature at time t1, and t1 and t2 be the start and end times of the unit time, respectively.

[0104] Step S1124: The rotor heat loss is obtained based on the specific heat capacity of the rotor material, the rotor mass, the rotor temperature at the second moment, and the rotor temperature at the third moment.

[0105] It should be noted that the specific heat capacity of the rotor material is an inherent property of the rotor material, affecting the heat absorbed or released when its temperature changes. Rotor mass refers to the total mass of the rotor. The rotor temperature at the second moment is the rotor temperature measured at the second moment, and the rotor temperature at the third moment is the rotor temperature measured at a slightly later time, used for comparison with the temperature at the second moment to calculate the temperature change.

[0106] The formula for rotor heat loss, i.e., the rotor heat loss temperature model, is as follows: Equation 5:

[0107] In the formula, C r M represents the specific heat capacity of the rotor material. r For rotor mass, T r1 and T r2 t1 and t2 are the rotor temperatures at the start and end points of a unit time, respectively, and t1 and t2 are the start and end points of a unit time, respectively.

[0108] Step S12: Establish a rotor operating temperature model based on the comprehensive power loss;

[0109] The rotor operating temperature model established based on the comprehensive power loss takes into account factors such as motor load, ambient temperature, and rotor physical characteristics, which can more accurately monitor rotor temperature in real time and can be conveniently used in subsequent steps.

[0110] In one feasible implementation, step S12 may include steps S121 to S122:

[0111] Step S121: Obtain the specific heat capacity of the stator material, the stator mass, the stator temperature at the first moment, and the stator temperature at the second moment;

[0112] The specific heat capacity of stator material refers to the amount of heat required per unit mass and per unit temperature change of stator material; stator mass refers to the total mass of the motor stator, which affects its ability to store and release heat; the stator temperature at the first moment and the stator temperature at the second moment represent the stator temperature at the sampling time points before and after the sampling time, respectively, and are obtained through stator NTC sampling.

[0113] Step S122: Establish a rotor operating temperature model based on the specific heat capacity of the stator material, the stator mass, the stator temperature at the first moment, the stator temperature at the second moment, and the comprehensive power loss.

[0114] The rotor operating temperature model is given by the following equation 6:

[0115] In the formula, C s M is the specific heat capacity of the stator material. s For stator mass, T S1 and T S2 These represent the stator temperatures at the first and second time points, respectively, with t1 and t2 being the sampling time points before and after the first sampling. P ω P is the stator power loss absorbed by the coolant. s_air P represents the power dissipation loss of the stator and its windings to the environment. r_air P represents the power loss dissipated by the rotor and magnets to the surrounding environment. r This is a temperature model for rotor heat loss.

[0116] Step S13: Obtain the rotor temperature based on the rotor operating state temperature model.

[0117] Using the temperature model established in step S12, combined with real-time monitored power loss data, the real-time temperature of the rotor is calculated. This temperature feedback can be used to monitor the thermal state of the system to ensure that the rotor operates within a safe and efficient operating range, or as a feedback signal to control the operation of the motor.

[0118] Furthermore, by substituting equations 1 through 5 into equation 6, we obtain the following equation 7:

[0119] By rearranging Equation 7 above, we can obtain the rotor temperature, which is calculated as follows: Equation 8:

[0120] In the formula, at the initial moment, the rotor temperature T r1 =T r0 =T0, where T0 is the ambient temperature, T r2 This refers to the rotor temperature.

[0121] Step S20: Upon receiving a heating command, at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment are opened according to the rotor temperature and the opening strategy to heat the windings between different phases.

[0122] It should be noted that the heating command is a signal sent from the VCU, indicating the start of the heating process.

[0123] Referring to Figure 2, Figure 2 is a schematic diagram of the heating command sending logic of the first embodiment of the battery pack heating method based on motor windings of this application.

[0124] As shown in Figure 2, after startup, the Battery Management System (BMS) controller detects that the battery pack temperature is below 10°C and sends a heating request command to the Vehicle Control Unit (VCU). Upon receiving the heating request command from the BMS, the VCU forwards it to the MCU motor controller. Upon receiving the heating command, the MCU motor controller begins operation. First, it determines whether the drive motor is operating. If not, the drive motor and generator are simultaneously heated by the MCU controller according to IGBT temperature, stator NTC temperature, rotor temperature estimation, and a closed-loop control opening strategy. Simultaneously, the water circulation system is opened to transfer heat from the motor side of the motor controller to the battery pack. If the vehicle drive motor is operating, the generator independently completes the heating process according to IGBT temperature, stator NTC temperature, rotor temperature estimation, and a closed-loop control opening strategy.

[0125] Additionally, it should be noted that power equipment refers to generators or drive motors and generators.

[0126] It should be noted that "phase" refers to three independent AC circuits, labeled U-phase, V-phase, and W-phase respectively. Specifically, the first phase, second phase, and third phase represent U-phase, V-phase, and W-phase, respectively. A bridge switch refers to a power electronic switching device in a motor controller, such as an insulated-gate bipolar transistor (IGBT). These devices form a full-bridge or half-bridge circuit, controlling the direction of current flow and the path from the power source to the motor.

[0127] When the motor windings are energized, the current flowing through the windings generates heat due to the resistance. In this embodiment, winding heating is achieved by controlling the motor's IGBTs or other switching devices to generate heat without producing mechanical movement.

[0128] Step S30: Transfer the heat generated during the heating of the winding to the battery pack;

[0129] Motors typically have a water circulation system for heat dissipation. This system needs to be opened so that the coolant can absorb the heat generated by the windings. The hot coolant is then pumped to the battery pack, where a heat exchanger transfers the heat to the battery pack, allowing the battery pack temperature to increase steadily.

[0130] Referring to Figure 3, which is a schematic diagram of the electric drive system architecture of the first embodiment of the battery pack heating method based on motor windings in this application.

[0131] As shown in Figure 3, the system comprises two main parts: an electric drive system and a power battery pack. The electric drive system and the power battery pack are connected via a high-voltage power supply circuit, and the motor control unit is responsible for controlling the operation of the motor unit. The power battery pack is cooled through a power battery cooling circuit, which includes cooling water pipes. In addition, the electric drive system also has a dedicated cooling circuit to maintain heat transfer. The locations of temperature acquisition points, motor windings, and motor rotor are also marked.

[0132] Step S40: According to the temperature protection strategy, stop the winding heating to complete the battery pack heating.

[0133] It should be noted that the temperature protection strategy is a set of safety measures used to monitor and control the temperature of the battery pack and motor windings to prevent the battery pack from overheating during the heating process and thus prevent damage to the battery pack.

[0134] This embodiment provides a battery pack heating method based on motor windings. By establishing and applying a rotor operating temperature model, combined with real-time monitoring of parameters such as coolant power loss, stator power dissipation to the environment, rotor and magnet power dissipation to the environment, and rotor heat loss, the heating process of the motor windings is precisely controlled. This solves the technical problem of how to efficiently and safely utilize the heat generated by the motor windings to preheat the battery pack without increasing additional hardware costs. Through precise temperature control and temperature protection strategies, this method not only improves the performance of the battery pack in low-temperature environments and the driving range of electric vehicles, but also avoids the risk of damage to the battery pack and motor due to overheating, achieving the beneficial effect of optimizing the electric vehicle thermal management system.

[0135] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in the first embodiment described above can be referred to the above description and will not be repeated hereafter. Based on this, please refer to Figure 4, step S20 of the battery pack heating method based on motor windings further includes steps S21 to S22:

[0136] Step S21: Upon receiving a heating command, the tube opening time period is obtained based on the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, the temperature of the negative temperature coefficient thermistor, the current temperature of the battery pack, the proportional-integral-derivative control strategy, and the tube opening heating strategy.

[0137] It should be noted that the temperature of the insulated gate bipolar transistor (IGBT) of the upper and lower bridge arm switches is the IGBT temperature. IGBTs are key components in motor controllers used to control the direction of current flow, and their operating temperature affects the thermal management and control strategy of the motor.

[0138] Please refer to Figure 5, which is a powertrain control system block diagram of the second embodiment of the battery pack heating method based on motor windings in this application.

[0139] As shown in Figure 5, the powertrain control system includes a motor M, a motor controller MCU, a high-voltage DC bus DC, ground GND, the motor's three-phase output lines (U, V, W), upper and lower bridge arms (U upper, U lower, V upper, V lower, W upper, W lower) controlling the U, V, and W switches respectively, and IGBT switching devices (gut, gub, gvt, gvb, gwt, gwb) related to each phase in the motor controller. Specifically, gut controls the upper bridge arm switch for phase U; gub controls the lower bridge arm switch for phase U; gvt controls the upper bridge arm switch for phase V; gvb controls the lower bridge arm switch for phase V; gwt controls the upper bridge arm switch for phase W; gwb controls the lower bridge arm switch for phase W; and corresponding control signal lines for controlling the motor's operating state. This powertrain control system is designed for new energy vehicles, achieving efficient vehicle drive and energy management through precise control of the motor's torque and speed.

[0140] Additionally, it's important to note that negative temperature coefficient (NTC) thermistor temperature refers to NTC temperature. An NTC is a temperature sensor whose resistance decreases as temperature increases. It's typically used to monitor the temperature of motor stators or other components. The current battery pack temperature represents the real-time temperature of the battery pack and is a crucial factor in determining whether heating is needed and to what extent. The proportional-integral-derivative (PID) control strategy, also known as the PID control algorithm, is a feedback control strategy used to calculate the control signal to reduce the deviation between the system output and the desired value. The proportional (P) response addresses the current deviation, the integral (I) response addresses the accumulated deviation, and the derivative (D) prediction of future changes in the deviation. The open-tube heating strategy is a control strategy used to determine when and how to operate the motor's IGBTs to control the heating of the motor windings.

[0141] In one feasible implementation, step S21 may include steps S211 to S213:

[0142] Step S211: Upon receiving a heating command, the rotor temperature control signal, the insulated gate bipolar transistor temperature, the negative temperature coefficient thermistor temperature, the current battery pack temperature, and the proportional-integral-derivative control strategy are used to obtain the following signals: rotor temperature control signal, insulated gate bipolar transistor temperature control signal, negative temperature coefficient thermistor temperature control signal, and current battery pack temperature control signal.

[0143] The rotor temperature control signal, the insulated gate bipolar transistor temperature control signal, the negative temperature coefficient thermistor temperature control signal, and the battery pack current temperature control signal are outputs obtained by inputting the rotor temperature, the insulated gate bipolar transistor temperature of the upper and lower bridge arm switches, the negative temperature coefficient thermistor temperature, and the battery pack current temperature into a proportional-integral-derivative control algorithm.

[0144] In addition, the calculation formulas for the rotor temperature control signal, the insulated gate bipolar transistor temperature control signal, the negative temperature coefficient thermistor temperature control signal, and the current battery pack temperature control signal are as follows: Equation 9: △t(k)=K p ×[t(k)-t(k-1)]+K i ×t(k)+K d ×[t(k)-2t(k-1)+t(k-2)] (Equation 9)

[0145] In the formula, K p For proportional gain, K p K is inversely proportional to the scale ratio. i K is the integral coefficient. d These are the differential coefficients. Δt(k) is the output signal of the PID controller, including Δt(k). igbt , as well as in, For rotor temperature control signal, Δt(k) igbt For the temperature control signal of the insulated gate bipolar transistor, This is the temperature control signal for a negative temperature coefficient thermistor. This is the current temperature control signal for the battery pack. t(k) is the IGBT temperature T at time k. igbt Motor stator NTC temperature T s Rotor online temperature estimation T r2 Current battery pack temperature T battery t(k-1) represents the IGBT temperature T at the previous time k-1. igbt Motor stator NTC temperature T s Rotor online temperature estimation T r2 Current battery pack temperature T battery The IGBT temperature, motor stator NTC temperature, and current battery pack temperature can be obtained by using a microcontroller's AD sampling and table lookup method.

[0146] Step S212: Obtain the target control signal based on the rotor temperature control signal, the insulated gate bipolar transistor temperature control signal, the negative temperature coefficient thermistor temperature control signal, and the current temperature control signal of the battery pack.

[0147] Compare Δt(k) igbt , as well as The maximum value Δt(k) is obtained. Max This maximum value is Δt(k). Max This is the target control signal.

[0148] Step S213: Obtain the tube opening time period based on the target control signal and the tube opening heating strategy.

[0149] It should be noted that the on-circuit heating strategy is a set of predefined rules or algorithms used to determine the on and off states of power electronic devices such as IGBTs in the motor controller, thereby heating the motor windings. The on-circuit time period is a time interval calculated based on the target control signal and the on-circuit heating strategy. During this time period, certain bridge arm switches of the motor will be activated for heating. In this embodiment, the on-circuit time period can be obtained from the time width of a single pulse.

[0150] Furthermore, the duration of a single pulse typically refers to the on-time of a switching device (such as a transistor or IGBT) within a PWM (Pulse Width Modulation) control cycle. This duration is also known as pulse width or duty cycle, and it determines the proportion of time the switching device is in the on-state within a PWM cycle. In this embodiment, the transmission frequency is 10kHz, meaning the period of a single pulse is 100µs.

[0151] The open-tube heating strategy represents the relationship between the single-pulse width t and the PID feedback quantity Δt(k) at a 10kHz emission frequency. A larger PID feedback quantity results in a larger pulse width, and a smaller PID feedback quantity results in a smaller pulse width. The single-pulse width is calculated as follows: t=ζ*Δt(k), t≤98us (Equation 10)

[0152] In the formula, ζ is a constant set by the software, and the most suitable value is selected through multiple experimental calibrations; Δt(k) is the PID feedback quantity, which needs to be adjusted in this embodiment. Max Substitute into Equation 10 to perform the calculation.

[0153] Step S22: By using the pipe opening strategy and the pipe opening time period, open at least two of the following: the first upper bridge arm switch of the first phase, the first lower bridge arm switch of the first phase, the second upper bridge arm switch of the second phase, the second lower bridge arm switch of the second phase, the third upper bridge arm switch of the third phase, and the third lower bridge arm switch of the third phase, to complete the winding heating between different phases.

[0154] It should be noted that the first upper bridge arm switch (GUT) and the first lower bridge arm switch (GUB) of the first phase are switching devices that control the U-phase current of the motor, typically using IGBTs or other types of power electronic devices. The coordinated operation of the upper and lower bridge arms controls the direction and magnitude of the current. Similarly, the second upper bridge arm switch (GVT) and the second lower bridge arm switch (GVB) of the second phase control the V-phase current; the activation mode of these switching devices determines the current state of the V-phase. The third upper bridge arm switch (GWT) and the third lower bridge arm switch (GWB) of the third phase control the W-phase current, thus completing the three-phase control of the three-phase motor.

[0155] During a defined opening period, the motor controller sends a signal to activate the selected bridge arm switch. This causes current to flow through the motor windings, and due to the resistance, the current generates heat, thus heating the windings.

[0156] In one feasible implementation, step S22 may include steps S221 to S226:

[0157] Step S221: Open the first upper arm switch and the second lower arm switch of the power equipment through the pipe opening strategy, and close the first lower arm switch, the second upper arm switch, the third upper arm switch and the third lower arm switch.

[0158] Step S222: During the period of pipe opening, close the first upper bridge arm switch and the second lower bridge arm switch, and open the first lower bridge arm switch and the second upper bridge arm switch.

[0159] Step S223: During the period of pipe opening, close the first lower bridge arm switch and the second upper bridge arm switch, and open the second upper bridge arm switch and the third lower bridge arm switch.

[0160] Step S224: During the period of pipe opening, close the second upper bridge arm switch and the third lower bridge arm switch, and open the second lower bridge arm switch and the third upper bridge arm switch.

[0161] Step S225: During the period of pipe opening, close the second lower bridge arm switch and the third upper bridge arm switch, and open the third upper bridge arm switch and the first lower bridge arm switch.

[0162] Step S226: During the opening period, close the third upper bridge arm switch and the first lower bridge arm switch, and open the third lower bridge arm switch and the first upper bridge arm switch to complete the winding heating between different phases.

[0163] Steps S221 to S226 represent the turn-on strategy. In this embodiment, the turn-on strategy is as follows: MCU power-on, high-voltage bus DC power-on, 6 bridge arms gut, gub, gvt, gvb, gwt, gwb are in the off state; gut / gvb turn on to heat the winding between UV; gub / gvt / gwt / gwb turn off; after a dead time of 2µs; gub / gvt turn on to heat the winding between UV; gut / gvb / gwt / gwb turn off; after a dead time of 2µs; gvt... / gwb turns on, heating the winding between V and W; gut / gub / gvb / gwt turns off; after a dead time of 2us; gvb / gwt turns on, heating the winding between V and W; gut / gub / gvt / gwb turns off; after a dead time of 2us; gwt / gub turns on, heating the winding between U and W; gut / gvt / gvb / gwb turns off; after a dead time of 2us; gwb / gut turns on, heating the winding between U and W; gut / gvt / gvb / gwt turns off.

[0164] In addition, the control process of the cyclic repetitive turn-on strategy involves a wave emission frequency of 10kHz, meaning that the period of a single wave emission pulse is 100us. At the same time, the temperature of the battery pack is monitored, and the target temperature is set to 35℃. Once the target temperature is reached, the cyclic turn-on strategy is stopped.

[0165] This embodiment provides a battery pack heating method based on motor windings. By applying a proportional-integral-derivative (PID) control strategy and a precise open-tube heating strategy, combined with real-time monitoring of rotor temperature, IGBT temperature, NTC temperature, and the current battery pack temperature, precise control of the motor winding heating process is achieved. By dynamically adjusting the conduction time of switching devices (such as IGBTs), i.e., adjusting the PWM duty cycle, the technical problem of how to efficiently and safely utilize the heat generated by the motor windings to preheat the battery pack without increasing additional hardware costs is solved. This achieves the beneficial effects of optimizing the performance of electric vehicles in low-temperature environments, improving battery pack heating efficiency, ensuring that the battery pack and motor operate within a safe temperature range, thereby extending their service life and improving the overall system energy efficiency.

[0166] Based on the first embodiment of this application, in the third embodiment of this application, the content that is the same as or similar to that in the first embodiment described above can be referred to the above description and will not be repeated hereafter. Based on this, please refer to Figure 6. After step S40, the battery pack heating method based on the motor winding further includes steps S41 to S42:

[0167] Step S41: Obtain a first preset temperature and a second preset temperature according to the temperature protection strategy, wherein the first preset temperature is greater than the second preset temperature.

[0168] It should be noted that the first preset temperature refers to a relatively high safe temperature threshold set in the temperature protection strategy. The heating source will be shut off when any one of the following temperatures reaches this value: rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, or the temperature of the negative temperature coefficient thermistor. The second preset temperature represents the maximum temperature at which the battery pack can be heated.

[0169] In this embodiment, the first preset temperature is 100°C and the second preset temperature is 35°C.

[0170] Step S42: When any one of the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, or the temperature of the negative temperature coefficient thermistor is greater than the first preset temperature, or the current temperature of the battery pack is greater than the second preset temperature, stop the winding heating and complete the battery pack heating.

[0171] If any of the rotor temperature, IGBT temperature, or NTC temperature exceeds the first preset temperature, or if the current battery pack temperature exceeds the second preset temperature, it is considered that the heating requirement has been met or there is a risk of overheating. In this case, a command needs to be sent to the motor controller to stop the winding heating process. After the winding heating stops, the battery pack heating process is completed.

[0172] This embodiment provides a battery pack heating method based on motor windings, which, by applying a temperature protection strategy, sets two key temperature thresholds (a first preset temperature of 100°C and a second preset temperature of 35°C). It utilizes real-time monitoring of rotor temperature, IGBT temperature, NTC temperature, and the current battery pack temperature, and automatically stops heating when any temperature exceeds these preset values. This solves the technical problem of effectively avoiding overheating during battery pack heating, achieving the beneficial effects of ensuring the battery pack and motor operate within a safe temperature range, preventing thermal damage, improving system reliability, and extending battery life.

[0173] This application also provides a battery pack heating device based on motor windings. Referring to Figure 7, the battery pack heating device based on motor windings includes:

[0174] Detection module 10 is used to detect rotor temperature through rotor operating state temperature model;

[0175] Heating module 20 is used to open at least two of the bridge arm switches of the first phase, second phase and third phase of the power equipment respectively according to the rotor temperature and the opening strategy when a heating command is received, so as to heat the windings between different phases.

[0176] The heat transfer module 30 is used to transfer the heat generated when the winding is heated to the battery pack;

[0177] The stop module 40 is used to stop the heating of the winding according to the temperature protection strategy, thereby completing the heating of the battery pack.

[0178] The battery pack heating device based on motor windings provided in this application, employing the battery pack heating method based on motor windings in the above embodiments, can solve the technical problem of how to efficiently and accurately preheat the battery pack using existing motor windings without increasing additional costs. Compared with the prior art, the beneficial effects of the battery pack heating device based on motor windings provided in this application are the same as those of the battery pack heating method based on motor windings provided in the above embodiments, and other technical features in the battery pack heating device based on motor windings are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0179] In one embodiment, the heating module 20 is further configured to, upon receiving a heating command, determine the opening time period based on the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, the temperature of the negative temperature coefficient thermistor, the current temperature of the battery pack, the proportional-integral-derivative control strategy, and the opening heating strategy; and to open at least two of the first upper bridge arm switch of the first phase, the first lower bridge arm switch of the first phase, the second upper bridge arm switch of the second phase, the second lower bridge arm switch of the second phase, the third upper bridge arm switch of the third phase, and the third lower bridge arm switch of the third phase of the power equipment through the opening strategy and the opening time period, thereby completing the winding heating between different phases.

[0180] In one embodiment, the heating module 20 is further configured to, upon receiving a heating command, obtain a rotor temperature control signal, an insulated gate bipolar transistor (IGBT) temperature control signal, a negative temperature coefficient (NTC) thermistor temperature control signal, and a battery pack current temperature control signal based on the rotor temperature, the insulated gate bipolar transistor (IGBT) temperature of the upper and lower bridge arm switches, the negative temperature coefficient (NTC) thermistor temperature control signal, the current battery pack temperature, and a proportional-integral-derivative (PI-DE) control strategy; obtain a target control signal based on the rotor temperature control signal, the IGBT temperature control signal, the NTC thermistor temperature control signal, and the battery pack current temperature control signal; and obtain an open-tube heating time period based on the target control signal and the open-tube heating strategy.

[0181] In one embodiment, the heating module 20 is further configured to open the first upper bridge arm switch and the second lower bridge arm switch of the power equipment via an opening pipe strategy, and close the first lower bridge arm switch, the second upper bridge arm switch, the third upper bridge arm switch, and the third lower bridge arm switch; during the opening pipe period, close the first upper bridge arm switch and the second lower bridge arm switch, and open the first lower bridge arm switch and the second upper bridge arm switch; during the opening pipe period, close the first lower bridge arm switch and the second upper bridge arm switch, and open the second upper bridge arm switch and the third lower bridge arm switch; during the opening pipe period, close the second upper bridge arm switch and the third lower bridge arm switch, and open the second lower bridge arm switch and the third upper bridge arm switch; during the opening pipe period, close the second lower bridge arm switch and the third upper bridge arm switch, and open the third upper bridge arm switch and the first lower bridge arm switch; during the opening pipe period, close the third upper bridge arm switch and the first lower bridge arm switch, and open the third lower bridge arm switch and the first upper bridge arm switch, thereby completing the winding heating between different phases.

[0182] In one embodiment, the detection module 10 is further configured to establish a rotor operating state temperature model; acquire coolant power loss, stator power dissipation to the environment, rotor and magnet power dissipation to the environment, and rotor heat loss; and obtain rotor temperature based on the stator power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, the rotor heat loss, and the rotor operating state temperature model.

[0183] In one embodiment, the detection module 10 is further configured to: obtain the coolant power loss based on the coolant density, cooling pipe cross-sectional area, coolant flow velocity, inlet water temperature, and outlet water temperature; obtain the stator power dissipation loss to the environment based on the stator surface convective heat transfer area, stator surface temperature, ambient temperature, and a preset convective heat transfer coefficient; obtain the rotor and magnet power dissipation loss to the environment based on the rotor surface convective heat transfer area, rotor temperature at a first moment, and a preset convective heat transfer coefficient; and obtain the rotor heat loss based on the rotor material specific heat capacity, rotor mass, rotor temperature at a second moment, and rotor temperature at a third moment.

[0184] In one embodiment, the stop module 40 is further configured to obtain a first preset temperature and a second preset temperature according to a temperature protection strategy, wherein the first preset temperature is greater than the second preset temperature; when any one of the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, and the temperature of the negative temperature coefficient thermistor is greater than the first preset temperature or the current temperature of the battery pack is greater than the second preset temperature, the winding heating is stopped and the battery pack heating is completed.

[0185] This application provides a battery pack heating device based on motor windings. The battery pack heating device based on motor windings includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the battery pack heating method based on motor windings in the above embodiment 1.

[0186] Referring now to Figure 8, a schematic diagram of a battery pack heating device based on motor windings suitable for implementing embodiments of this application is shown. The battery pack heating device based on motor windings in embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. The battery pack heating device based on motor windings shown in Figure 8 is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0187] As shown in Figure 8, the battery pack heating device based on motor windings may include a processing unit 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 1002 or a program loaded from storage device 1003 into random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the battery pack heating device based on motor windings. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the battery pack heating device based on motor windings to communicate wirelessly or wiredly with other devices to exchange data. Although the figure shows a battery pack heating device based on motor windings with various systems, it should be understood that it is not required to implement or possess all the systems shown. More or fewer systems can be implemented alternatively.

[0188] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0189] The battery pack heating device based on motor windings provided in this application, employing the battery pack heating method based on motor windings in the above embodiments, solves the technical problem of how to efficiently and accurately preheat the battery pack using existing motor windings without increasing additional costs. Compared with the prior art, the beneficial effects of the battery pack heating device based on motor windings provided in this application are the same as those of the battery pack heating method based on motor windings provided in the above embodiments, and other technical features of this battery pack heating device based on motor windings are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0190] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0191] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0192] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the battery pack heating method based on motor windings in the above embodiments.

[0193] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0194] The aforementioned computer-readable storage medium may be included in a battery pack heating device based on motor windings; or it may exist independently and not assembled into a battery pack heating device based on motor windings.

[0195] The aforementioned computer-readable storage medium carries one or more programs that, when executed by a battery pack heating device based on motor windings, cause the battery pack heating device based on motor windings to: detect the rotor temperature through a rotor operating state temperature model; upon receiving a heating command, open at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment according to the rotor temperature and the opening strategy, respectively, to perform winding heating between different phases; transfer the heat generated during the winding heating to the battery pack; and stop the winding heating according to a temperature protection strategy, thus completing the battery pack heating.

[0196] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0197] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0198] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0199] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described battery pack heating method based on motor windings. This solves the technical problem of how to efficiently and accurately preheat a battery pack using existing motor windings without incurring additional costs. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the battery pack heating method based on motor windings provided in the above embodiments, and will not be repeated here.

[0200] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the battery pack heating method based on motor windings as described above.

[0201] The computer program product provided in this application solves the technical problem of how to efficiently and accurately preheat a battery pack using existing motor windings without incurring additional costs. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the battery pack heating method based on motor windings provided in the above embodiments, and will not be repeated here.

[0202] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A battery pack heating method based on motor winding, wherein, The method includes: Rotor temperature is detected using a rotor operating state temperature model; Upon receiving a heating command, at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment are opened according to the rotor temperature and the opening strategy to heat the windings between different phases. The heat generated when the winding is heated is transferred to the battery pack; According to the temperature protection strategy, the heating of the winding is stopped, and the battery pack heating is completed.

2. The method of claim 1, wherein, The step of opening at least two of the bridge arm switches of the first phase, second phase, and third phase of the power equipment respectively, according to the rotor temperature and the opening strategy, to perform winding heating between different phases upon receiving a heating command includes: Upon receiving a heating command, the tube opening time period is obtained based on the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, the temperature of the negative temperature coefficient thermistor, the current temperature of the battery pack, the proportional-integral-derivative control strategy, and the tube opening heating strategy. By opening at least two of the following switches according to the opening strategy and the opening time period: the first upper bridge arm switch of the first phase, the first lower bridge arm switch of the first phase, the second upper bridge arm switch of the second phase, the second lower bridge arm switch of the second phase, the third upper bridge arm switch of the third phase, and the third lower bridge arm switch of the third phase, winding heating between different phases is completed.

3. The method of claim 2, wherein, The step of determining the tube-opening time period upon receiving a heating command, based on the rotor temperature, the insulated gate bipolar transistor temperature of the upper and lower bridge arm switches, the negative temperature coefficient thermistor temperature, the current battery pack temperature, the proportional-integral-derivative control strategy, and the tube-opening heating strategy, includes: Upon receiving a heating command, the rotor temperature control signal, the insulated gate bipolar transistor temperature of the upper and lower bridge arm switches, the negative temperature coefficient thermistor temperature, the current battery pack temperature, and the proportional-integral-derivative control strategy are used to obtain the rotor temperature control signal, the insulated gate bipolar transistor temperature control signal, the negative temperature coefficient thermistor temperature control signal, and the current battery pack temperature control signal. The target control signal is obtained based on the rotor temperature control signal, the insulated gate bipolar transistor temperature control signal, the negative temperature coefficient thermistor temperature control signal, and the current temperature control signal of the battery pack. The opening time period is obtained based on the target control signal and the opening heating strategy.

4. The method of claim 2, wherein, The step of opening at least two of the following components—the first upper bridge arm switch of the first phase, the first lower bridge arm switch of the first phase, the second upper bridge arm switch of the second phase, the second lower bridge arm switch of the second phase, the third upper bridge arm switch of the third phase, and the third lower bridge arm switch of the third phase—to complete winding heating between different phases via the opening strategy and the opening time period: The first upper arm switch and the second lower arm switch of the power equipment are opened by the pipe opening strategy, and the first lower arm switch, the second upper arm switch, the third upper arm switch and the third lower arm switch are closed. During the period of pipe opening, the first upper bridge arm switch and the second lower bridge arm switch are closed, and the first lower bridge arm switch and the second upper bridge arm switch are opened. During the period of pipe opening, the first lower bridge arm switch and the second upper bridge arm switch are closed, and the second upper bridge arm switch and the third lower bridge arm switch are opened. During the specified opening period, the second upper bridge arm switch and the third lower bridge arm switch are closed, and the second lower bridge arm switch and the third upper bridge arm switch are opened. During the period of time when the pipe is opened, the second lower bridge arm switch and the third upper bridge arm switch are closed, and the third upper bridge arm switch and the first lower bridge arm switch are opened. During the specified opening period, the third upper bridge arm switch and the first lower bridge arm switch are closed, and the third lower bridge arm switch and the first upper bridge arm switch are opened to complete the winding heating between different phases.

5. The method of claim 1, wherein, The step of detecting rotor temperature using a rotor operating state temperature model includes: Obtain the overall power loss; A rotor operating temperature model is established based on the comprehensive power loss. The rotor temperature is obtained based on the rotor operating state temperature model.

6. The method of claim 5, wherein, The steps for obtaining the overall power loss include: The power loss of the coolant, the power loss of the stator to the environment, the power loss of the rotor and magnets to the environment, and the heat loss of the rotor are obtained. The comprehensive power loss is obtained based on the stator power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, and the rotor heat loss.

7. The method of claim 6, wherein, The steps for obtaining the coolant power loss, the stator power dissipation to the environment, the rotor and magnet power dissipation to the environment, and the rotor heat loss include: The power loss of the coolant is obtained based on the coolant density, the cross-sectional area of ​​the cooling pipe, the coolant flow velocity, the inlet water temperature, and the outlet water temperature. The power loss of the stator to the environment is obtained based on the stator surface convective heat transfer area, stator surface temperature, ambient temperature and preset convective heat transfer coefficient. Based on the convective heat transfer area of ​​the rotor surface, the rotor temperature at the first moment, and the preset convective heat transfer coefficient, the power dissipation loss of the rotor and magnets to the environment is obtained. The rotor heat loss is obtained based on the specific heat capacity of the rotor material, the rotor mass, the rotor temperature at the second moment, and the rotor temperature at the third moment.

8. The method of claim 5, wherein, The step of establishing the rotor operating temperature model based on the comprehensive power loss includes: Obtain the specific heat capacity of the stator material, the stator mass, the stator temperature at the first moment, and the stator temperature at the second moment; A rotor operating temperature model is established based on the specific heat capacity of the stator material, the stator mass, the stator temperature at the first moment, the stator temperature at the second moment, and the comprehensive power loss.

9. The method of claim 1, wherein, The step of stopping the winding heating and completing the battery pack heating according to the temperature protection strategy includes: A first preset temperature and a second preset temperature are obtained according to a temperature protection strategy, wherein the first preset temperature is greater than the second preset temperature. When any one of the rotor temperature, the temperature of the insulated gate bipolar transistor of the upper and lower bridge arm switches, or the temperature of the negative temperature coefficient thermistor is greater than the first preset temperature, or when the current temperature of the battery pack is greater than the second preset temperature, the winding heating is stopped, and the battery pack heating is completed.

10. A battery pack heating arrangement based on motor winding, wherein, The device includes: The detection module is used to detect rotor temperature using a rotor operating state temperature model. The heating module is used to open at least two of the bridge arm switches of the first phase, the second phase, and the third phase of the power equipment respectively according to the rotor temperature and the opening strategy when a heating command is received, so as to heat the windings between different phases. A heat transfer module is used to transfer the heat generated when the winding is heated to the battery pack; The stop module is used to stop the heating of the winding according to the temperature protection strategy, thereby completing the heating of the battery pack.

11. A battery pack heating apparatus based on motor winding, wherein, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the battery pack heating method based on motor windings as described in any one of claims 1 to 9.

12. A storage medium, wherein, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the battery pack heating method based on motor windings as described in any one of claims 1 to 9.

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