Heating control method, device, vehicle-mounted equipment and vehicle

Abstract

The present invention relates to a heating control method, device, vehicle-mounted equipment and vehicle. The method obtains the temperature of a target component inside the vehicle, the temperature of a motor stator and the input current of the motor stator. If the temperature of the target component is less than a first preset temperature threshold, the motor stator heating power and the motor stator current amplitude are given based on the temperature of the target component. The motor stator current amplitude and the motor stator heating power are combined to correct the motor stator current amplitude. According to the correction result and a preset basic voltage vector switching function of an inverter, the cost value of a basic voltage vector is determined. The basic voltage vector with the smallest cost value is used as a voltage output terminal, and different insulated gate bipolar transistors in the inverter are controlled to be turned on and the motor stator is controlled to work, so as to heat the target component. The present invention can reduce the number of inverter switches, reduce the inverter temperature rise, improve the inverter conversion efficiency and service life, and improve the accuracy of the motor stator heating power output.

Description

Technical Field

[0001] The present invention relates to the technical field of heating control, and in particular to a heating control method, device, vehicle-mounted equipment and vehicle. Background Art

[0002] With the development of modern automobiles, electric vehicles are becoming more and more popular among consumers. Among them, lithium batteries are the core energy storage devices of new energy electric vehicles. Under normal working temperature, they have the advantages of high energy density and fast charging and discharging. However, due to the use of electrolytes, the conductivity of lithium batteries decreases greatly under low temperature conditions, and the charging and discharging performance is also affected. It can be said that under low temperature conditions, battery performance degradation has become one of the main difficulties that need to be overcome for the popularization of electric vehicles, restricting the development of electric vehicles in northern my country. To solve this problem, new energy electric vehicle manufacturers initially used PTC (Positive Temperature Coefficient) heaters to heat the battery pack. PTC heaters can effectively achieve battery heating. However, after using PTC heaters to heat the battery pack, the cost of the entire vehicle also increases. In addition, PTC heaters also face the problems of aging and increased system failure rate. Considering the hardware cost and reliability, more and more OEMs use the method of heating the battery pack by heating the motor stator resistance.

[0003] For example, the Chinese invention patent "Asynchronous motor heating control method, device, equipment and storage medium" with application publication number CN114285352A directly uses a given direct-axis current and a smaller quadrature-axis current to make the three-phase current an alternating current for heating. Although this makes the hardware switch heat evenly, it gives a certain value of torque current, which will cause torque pulsation and result in a poor user experience.

[0004] For example, the Chinese invention patent application publication number CN117856690A is entitled "A motor controller,

[0005] "Powertrain and Electric Vehicles" uses a variable current solution to make the three-phase current a square wave or a step wave, which to a certain extent solves the problem of excessive temperature rise during heating that reduces the life of the switch hardware. However, the direct-axis current is given in steps. When high-power heating occurs, the large current step jump is prone to produce unexpected torque and slight shaking.

[0006] In summary, both of the above solutions use the proportional-integral control method in the current loop control. Although this method can achieve accurate error adjustment, it does not optimize the number of inverter switching times and cannot solve the technical problem that the high-frequency switching of the inverter will cause temperature rise, increase inverter switching losses, and reduce its service life. In addition, neither of the above two solutions explains the technical problem that when the motor stator temperature changes, the motor power accuracy decreases and the heating power cannot be guaranteed to be constant.

[0007] Therefore, it is necessary to improve the heating control method in the related art. Summary of the invention

[0008] In view of the above-mentioned shortcomings of the prior art, the present application provides a heating control method, device, vehicle-mounted equipment and vehicle to solve the above-mentioned technical problems.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] According to one aspect of an embodiment of the present application, a heating control method is provided, the heating control method comprising: obtaining a temperature of a target component inside a vehicle, a motor stator temperature, and a motor stator input current, the target component comprising a power battery; if the temperature of the target component is less than a first preset temperature threshold, then based on the temperature of the target component, a motor stator heating power and a motor stator current amplitude are given, based on the motor stator temperature and a target mapping relationship, the motor stator resistance is estimated, and the motor stator current amplitude is corrected in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power; the target mapping relationship is used to characterize the relationship between the motor stator temperature and the motor stator resistance;

[0011] The motor stator input current is transformed to obtain the direct-axis current feedback value and the quadrature-axis current feedback value of the motor stator at the current moment; the cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter; the basic voltage vector with the smallest cost value is used as the voltage output terminal to control the conduction of different insulated gate bipolar transistors in the inverter to control the motor stator to heat the target component.

[0012] In one embodiment of the present application, the process of correcting the motor stator current amplitude in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power includes: estimating the motor stator power feedback value based on the motor stator current amplitude and the motor stator resistance; taking the difference between the motor stator heating power and the motor stator power feedback value as the power error; adjusting the power error to obtain a current amplitude correction value; and taking the difference between the motor stator current amplitude and the current amplitude correction value as the correction result.

[0013] In one embodiment of the present application, the process of transforming the motor stator input current to obtain the direct-axis current feedback value of the motor stator and the quadrature-axis current feedback value of the motor stator at the current moment includes: transforming the motor stator input current into a two-phase input current; performing rotational transformation on the two-phase input current to obtain the direct-axis current feedback value of the motor stator and the quadrature-axis current feedback value of the motor stator at the current moment.

[0014] In one embodiment of the present application, the process of determining the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter includes: obtaining the number of motor pole pairs, the mechanical angle of the motor rotor, and the inverter voltage; taking the product of the number of motor pole pairs and the mechanical angle of the motor rotor as the electrical angle; determining the direct-axis voltage component of the basic voltage vector and the quadrature-axis voltage component of the basic voltage vector based on the electrical angle, the preset basic voltage vector switching function, and the inverter voltage; and obtaining the cost value of the basic voltage vector according to the direct-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the direct-axis voltage component and the quadrature-axis voltage component of the basic voltage vector. The quadrature-axis voltage component, the direct-axis current feedback value and the quadrature-axis current feedback value are used to predict the direct-axis current increment of the motor stator and the quadrature-axis current increment of the motor stator; the sum of the direct-axis current feedback value and the direct-axis current increment is used as the direct-axis current prediction value of the motor stator at the next moment, and the sum of the quadrature-axis current feedback value and the quadrature-axis current increment is used as the quadrature-axis current prediction value of the motor stator at the next moment; based on the correction result, the direct-axis current prediction value, the quadrature-axis current prediction value and the preset basic voltage vector switching function, the cost value of the basic voltage vector is determined.

[0015] In one embodiment of the present application, if the correction result includes a given value of the direct-axis current of the motor stator and a given value of the quadrature-axis current of the motor stator, the calculation formula of the cost value of the basic voltage vector includes: ,in, Indicates The cost of a basic voltage vector, Indicates the given value of direct-axis current, Indicates The predicted value of the direct axis current at time Indicates the given value of the quadrature-axis current, Indicates The predicted value of the quadrature axis current at time Indicates Moment The switching function of the basic voltage vector, Indicates Moment The switching function of the basic voltage vector, Indicates the weight value of the number of switches, Represents the magnitude of the basic voltage vector, and the direct-axis current given value is expressed in the form of a sinusoidal signal.

[0016] In one embodiment of the present application, the calculation formula of the direct-axis voltage component includes: ,in, Indicates Moment The direct-axis voltage component of the fundamental voltage vector, Indicates the electrical angle, Indicates Moment The switching function of the basic voltage vector, represents the inverter voltage; the calculation formula of the quadrature axis voltage component includes: ,in, Indicates Moment The quadrature-axis voltage components of the basic voltage vectors, Indicates the electrical angle, Indicates Moment The switching function of the basic voltage vector, Indicates the inverter voltage.

[0017] In one embodiment of the present application, the calculation formula of the direct-axis current increment includes: ,in, represents the direct axis current increment, represents the sampling period, represents the direct-axis inductance of the motor stator, represents the motor stator resistance, Indicates The predicted value of the direct axis current at time Indicates the synchronous speed of the motor rotor. represents the quadrature-axis inductance of the motor stator, Indicates The predicted value of the quadrature axis current at time Indicates Moment The direct-axis voltage component of a basic voltage vector; the calculation formula of the quadrature-axis current increment includes: ,in, represents the quadrature axis current increment, represents the sampling period, represents the quadrature-axis inductance of the motor stator, represents the motor stator resistance, Indicates The predicted value of the quadrature axis current at time Indicates the synchronous speed of the motor rotor. represents the direct-axis inductance of the motor stator, Indicates The predicted value of the direct axis current at time represents the permanent magnet flux, Indicates Moment The quadrature-axis voltage component of the first basic voltage vector.

[0018] In one embodiment of the present application, before estimating the motor stator resistance, the heating control method includes: measuring different temperatures of the motor stator and the heating power of the motor stator at different temperatures during the operation of the motor stator; fitting different temperatures and heating powers at different temperatures to obtain the relationship between the motor stator temperature and the heating power; determining the target mapping relationship based on the mapping relationship between the heating power and the motor stator resistance and the relationship between the motor stator temperature and the heating power.

[0019] In one embodiment of the present application, the process of giving the motor stator heating power and the motor stator current amplitude based on the temperature of the target component includes: determining the working gear of the motor stator based on the comparison result of the temperature of the target component and the second preset temperature threshold; the second preset temperature threshold is less than the first preset temperature threshold; according to the working gear, the motor stator heating power and the motor stator current amplitude are given.

[0020] According to one aspect of an embodiment of the present application, a heating control device is provided, the heating control device comprising: a temperature acquisition module, used to acquire the temperature of a target component inside a vehicle, a motor stator temperature, and a motor stator input current, the target component comprising a power battery; a current correction module, used to, if the temperature of the target component is less than a first preset temperature threshold, give a motor stator heating power and a motor stator current amplitude based on the temperature of the target component, estimate the motor stator resistance based on the motor stator temperature and a target mapping relationship, and correct the motor stator current amplitude in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power. ; The target mapping relationship is used to characterize the relationship between the motor stator temperature and the motor stator resistance; a cost determination module is used to transform the motor stator input current to obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment; the cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter; a conduction control module is used to use the basic voltage vector with the smallest cost value as the voltage output terminal, and control the conduction of different insulated gate bipolar transistors in the inverter to control the motor stator to heat the target component.

[0021] According to one aspect of an embodiment of the present application, a vehicle-mounted device is provided, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the vehicle-mounted device implements the heating control method as described above.

[0022] According to one aspect of an embodiment of the present application, a vehicle is provided, the vehicle comprising the apparatus as described above or the vehicle-mounted equipment as described above.

[0023] Beneficial effects of the present invention: The present invention obtains the temperature of a target component inside a vehicle, the temperature of a motor stator, and the input current of a motor stator. If the temperature of the target component is less than a first preset temperature threshold, the motor stator heating power and the motor stator current amplitude are given based on the temperature of the target component. The motor stator resistance is estimated based on the mapping relationship between the motor stator temperature and the target. The motor stator current amplitude is corrected in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power. The motor stator input current is transformed to obtain a direct-axis current feedback value of the motor stator at the current moment and a quadrature-axis current feedback value of the motor stator at the current moment. The cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter. The basic voltage vector with the smallest cost value is used as the voltage output terminal to control the conduction of different insulated gate bipolar transistors in the inverter. The motor stator is controlled to heat the target component. In the above process, the cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter, and the basic voltage vector with the smallest cost value is selected as the voltage output terminal, so as to reduce the number of inverter switches, reduce the inverter temperature rise, and improve the inverter conversion efficiency and service life; in addition, the motor stator current amplitude is corrected in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power, so as to improve the accuracy of the motor stator heating power output and help keep the heating power of the motor stator constant; the direct-axis current set value is a sinusoidal signal, which can make the six insulated gate bipolar transistors in the inverter alternately turned on, avoiding the technical problem of rapid heating caused by the continuous conduction of the three insulated gate bipolar transistors in the inverter when the direct-axis current is DC, thereby extending the static heating time.

[0024] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0026] Figure 1 is a schematic diagram of an exemplary system architecture shown in an exemplary embodiment of the present application;

[0027] Figure 2 is a flow chart of a heating control method shown in an exemplary embodiment of the present application;

[0028] Figure 3 is a flow chart of a motor working process shown in an exemplary embodiment of the present application;

[0029] Figure 4 is a schematic diagram of a power closed-loop correction module shown in an exemplary embodiment of the present application;

[0030] Figure 5 is a schematic diagram of a current loop control module shown in an exemplary embodiment of the present application;

[0031] Figure 6 It is a current following condition of the direct-quadrature axis when the current loop control module adopts the proportional-integral control algorithm as shown in an exemplary embodiment of the present application;

[0032] Figure 7 It is a switching condition of the inverter when the current loop control module adopts the proportional integral control algorithm shown in an exemplary embodiment of the present application;

[0033] Figure 8 It is an exemplary embodiment of the present application showing the current following condition of the direct-quadrature axis when the current loop control module adopts the model predictive control algorithm;

[0034] Fig. 9 It is a switching condition of the inverter when the current loop control module adopts the model predictive control algorithm shown in an exemplary embodiment of the present application;

[0035] Fig.10 is a heating power waveform diagram of a motor stator when a power closed-loop correction module is not used, shown in an exemplary embodiment of the present application;

[0036] Fig.11 is a heating power waveform diagram of a motor stator when a power closed-loop correction module is used, shown in an exemplary embodiment of the present application;

[0037] Fig.12 is a direct-axis current waveform diagram shown in an exemplary embodiment of the present application;

[0038] Fig.13 is a flow chart of a heating control method shown in another exemplary embodiment of the present application;

[0039] Fig.14 is a block diagram of a heating control device shown in an exemplary embodiment of the present application;

[0040] Fig.15 A schematic diagram of the structure of a computer system of a vehicle-mounted device suitable for implementing an embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] Here, exemplary embodiments will be described in detail, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0042] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0043] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0044] The term "multiple" as used in this application refers to two or more than two. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0045] The technical solution of the embodiment of the present application involves related technologies such as heating control, which is specifically described by the following embodiments:

[0046] Figure 1 It is a schematic diagram of an exemplary system architecture shown in an exemplary embodiment of the present application.

[0047] Reference Figure 1As shown, the system architecture may include a data acquisition device 101 and an onboard controller 102. The onboard controller 102 may be at least one of a desktop graphics processing unit (GPU) computer, a GPU computing cluster, a neural network computer, etc. Relevant technicians may use the onboard controller 102 to estimate the motor stator resistance based on the temperature of the target component, the motor stator heating power and the motor stator current amplitude, and the motor stator temperature and target mapping relationship if the temperature of the target component is less than the first preset temperature threshold. The motor stator current amplitude, the motor stator resistance, and the motor stator heating power are combined to correct the motor stator current amplitude, transform the motor stator input current, and obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment; according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter, determine the cost value of the basic voltage vector, use the basic voltage vector with the smallest cost value as the voltage output terminal, and control the conduction of different insulated gate bipolar transistors in the inverter to control the motor stator to heat the target component. The data acquisition device 101 is used to collect the temperature of the target components inside the vehicle, the motor stator temperature, and the motor stator input current. In this embodiment, the data acquisition device 101 uses sensors and other equipment to collect the temperature of the target components inside the vehicle, the motor stator temperature, and the motor stator input current, and provides them to the vehicle controller 102 for processing.

[0048] Schematically, after the vehicle controller 102 obtains the temperature of the target component inside the vehicle, the motor stator temperature, and the motor stator input current from the data acquisition device 101, if the temperature of the target component is less than the first preset temperature threshold, then based on the temperature of the target component, the motor stator heating power and the motor stator current amplitude are given, and based on the motor stator temperature and the target mapping relationship, the motor stator resistance is estimated, and the motor stator current amplitude is corrected in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power, and the motor stator input current is transformed to obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment; according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter, the cost value of the basic voltage vector is determined, and the basic voltage vector with the smallest cost value is used as the voltage output end to control different insulation in the inverter. The gate bipolar transistor is turned on to control the motor stator to heat the target component. In the above process, the cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter, and the basic voltage vector with the smallest cost value is selected as the voltage output terminal, so as to reduce the number of inverter switching times, reduce the inverter temperature rise, and improve the inverter conversion efficiency and service life; in addition, the motor stator current amplitude is corrected in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power, so as to improve the accuracy of the motor stator heating power output and help keep the motor stator heating power constant; the direct-axis current set value is a sinusoidal signal, which can make the 6 insulated gate bipolar transistors in the inverter alternately turned on, avoiding the technical problem of rapid heating caused by the continuous conduction of the 3 insulated gate bipolar transistors in the inverter when the direct-axis current is DC, thereby extending the static heating time.

[0049] It should be noted that the heating control method provided in the embodiment of the present application is generally executed by the vehicle-mounted controller 102 , and accordingly, the heating control device is generally disposed in the vehicle-mounted controller 102 .

[0050] The implementation details of the technical solution of the embodiment of the present application are described in detail below:

[0051] Figure 2 is a flowchart of a heating control method shown in an exemplary embodiment of the present application. The heating control method can be executed by a computing processing device. The computing processing device can be Figure 1 The vehicle controller 102 shown in FIG. Figure 2 As shown, the heating control method at least includes steps S210 to S240, which are described in detail as follows:

[0052] In step S210 , the temperature of the target component inside the vehicle, the temperature of the motor stator, and the input current of the motor stator are acquired.

[0053] In one embodiment of the present application, the temperature of the target component and the motor stator temperature are acquired by temperature sensors, etc., and the motor stator input current is acquired by current sensors, etc. The target components include but are not limited to power batteries, seats, rearview mirrors, and windshields.

[0054] In this embodiment, considering the heating demand inside the vehicle, the target area may also be heated, and the target area includes but is not limited to the vehicle cabin.

[0055] In step S220, if the temperature of the target component is lower than the first preset temperature threshold, the motor stator heating power and the motor stator current amplitude are given based on the temperature of the target component, and the motor stator resistance is estimated based on the motor stator temperature and the target mapping relationship. The motor stator current amplitude, the motor stator resistance, and the motor stator heating power are combined to correct the motor stator current amplitude.

[0056] In this embodiment, the first preset temperature threshold needs to be set according to actual conditions and is not specifically limited here.

[0057] In this embodiment, the target mapping relationship is used to characterize the relationship between the motor stator temperature and the motor stator resistance. The process of calibrating the target mapping relationship includes: (1) measuring different temperatures of the motor stator and the heat generation power of the motor stator at different temperatures during the operation of the motor stator; (2) fitting different temperatures and heat generation powers at different temperatures to obtain the relationship between the motor stator temperature and the heat generation power; (3) determining the target mapping relationship based on the mapping relationship between the heat generation power and the motor stator resistance and the relationship between the motor stator temperature and the heat generation power.

[0058] In this embodiment, after obtaining the motor stator temperature, the motor stator resistance is determined according to the change data of the motor stator resistance with the motor stator temperature, and the motor stator power feedback value is estimated according to the motor stator current amplitude and the motor stator resistance. Based on the difference between the motor stator heating power and the motor stator power feedback value, the motor stator current amplitude is corrected in real time to improve the accuracy of the motor stator heating power output, which is conducive to keeping the heating power constant.

[0059] In step S230, the motor stator input current is transformed to obtain the direct-axis current feedback value of the motor stator and the quadrature-axis current feedback value of the motor stator at the current moment; the cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter.

[0060] In this embodiment, the process of determining the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter includes: (1) obtaining the number of motor pole pairs, the mechanical angle of the motor rotor, and the inverter voltage; (2) taking the product of the number of motor pole pairs and the mechanical angle of the motor rotor as the electrical angle; (3) determining the direct-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the electrical angle, the preset basic voltage vector switching function, and the inverter voltage; (4) determining the direct-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the direct-axis current feedback value and the quadrature-axis current feedback value of the inverter; and (5) determining the quadrature-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the direct-axis current feedback value and the quadrature-axis current feedback value of the inverter. The direct-axis voltage component, the quadrature-axis voltage component, the direct-axis current feedback value and the quadrature-axis current feedback value are used to predict the direct-axis current increment and the quadrature-axis current increment of the motor stator; (5) the sum of the direct-axis current feedback value and the direct-axis current increment is used as the direct-axis current prediction value of the motor stator at the next moment, and the sum of the quadrature-axis current feedback value and the quadrature-axis current increment is used as the quadrature-axis current prediction value of the motor stator at the next moment; (6) based on the correction result, the direct-axis current prediction value, the quadrature-axis current prediction value and the preset basic voltage vector switching function, the cost value of the basic voltage vector is determined.

[0061] In step S240, the basic voltage vector with the minimum cost value is used as the voltage output terminal to control different insulated gate bipolar transistors in the inverter to be turned on, so as to control the motor stator to heat the target component.

[0062] In this embodiment, the basic voltage vector with the smallest substitution value is selected as the voltage output terminal, which reduces the switching times of the inverter, reduces the temperature rise of the inverter, and improves the conversion efficiency and service life of the inverter.

[0063] In one embodiment of the present application, the process of correcting the motor stator current amplitude in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power includes:

[0064] The motor stator power feedback value is estimated based on the motor stator current amplitude and the motor stator resistance.

[0065] In this embodiment, the calculation formula of the motor stator power feedback value includes:

[0066] Formula (1)

[0067] in, Indicates the motor stator power feedback value, Indicates that the motor stator is The current amplitude at the moment, Indicates the motor stator resistance.

[0068] The difference between the motor stator heating power and the motor stator power feedback value is taken as the power error.

[0069] In this embodiment, the calculation formula of the power error includes:

[0070] Formula (2)

[0071] in, represents the power error, Indicates the motor stator heating power, Indicates the motor stator power feedback value.

[0072] The power error is adjusted to obtain a current amplitude correction value.

[0073] In this embodiment, a PI (proportional integral controller) is used to adjust the power error, and the calculation formula of the current amplitude correction value includes:

[0074] Formula (3)

[0075] in, Indicates the current amplitude correction value, represents the proportional coefficient of the proportional-integral controller, represents the integral coefficient of the proportional-integral controller, represents the Laplace operator.

[0076] The difference between the motor stator current amplitude and the current amplitude correction value is taken as the correction result.

[0077] In this embodiment, the calculation formula of the correction result includes:

[0078] Formula (4)

[0079] in, Indicates the correction result. Indicates that the motor stator is The current amplitude at the moment, Indicates the current amplitude correction value.

[0080] In this embodiment, taking into account the influence of the increase in the temperature of the motor stator resistance on the actual heating power of the motor stator, after determining the motor stator resistance according to the motor stator temperature, the motor stator current amplitude is corrected in real time by proportional integral adjustment of the power error, so as to achieve accurate output of the actual heating power of the motor stator. This solves the technical problem that in the process of continuous heating of the motor, even if the motor stator has the same input current, the actual heating power of the motor stator will increase with the heating time and the actual heating power of the motor stator cannot be kept constant.

[0081] In one embodiment of the present application, the process of transforming the motor stator input current to obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment includes:

[0082] Convert the motor stator input current into two-phase input current.

[0083] In this embodiment, the motor stator input current is a three-phase current , , The method of converting the motor stator input current into a two-phase input current adopts Clark transformation, and the calculation formula for converting the motor stator input current into a two-phase input current includes:

[0084] Formula (5)

[0085] in, , , represents the three-phase current in the synchronous rotating coordinate system, , Represents the two-phase current in the stationary coordinate system.

[0086] The two-phase input current is rotationally transformed to obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment.

[0087] In this embodiment, the Park transformation is used to perform rotation transformation on the two-phase input current. The calculation formula for performing Park transformation on the two-phase input current includes:

[0088] Formula (6)

[0089] in, , represents the two-phase current in the stationary coordinate system, Indicates that the motor stator is The direct-axis current feedback value at the moment, Indicates that the motor stator is The quadrature-axis current feedback value at the moment The moment is the current moment, The moment is taken as the previous moment, moment as the next moment.

[0090] In one embodiment of the present application, the process of determining the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter includes:

[0091] Obtain the number of motor pole pairs, motor rotor mechanical angle, and inverter voltage.

[0092] In this embodiment, the mechanical angle of the motor rotor is detected by a resolver sensor or other equipment, and the inverter voltage is collected by a voltage sensor or other equipment.

[0093] The product of the number of motor pole pairs and the mechanical angle of the motor rotor is taken as the electrical angle.

[0094] In this embodiment, the calculation formula of the electrical angle includes:

[0095] Formula (7)

[0096] in, Indicates the electrical angle, Indicates the mechanical angle of the motor rotor, Indicates the number of motor pole pairs.

[0097] Based on the electrical angle, the preset basic voltage vector switching function, and the inverter voltage, a direct-axis voltage component of the basic voltage vector and a quadrature-axis voltage component of the basic voltage vector are determined.

[0098] In this embodiment, the calculation formula of the direct-axis voltage component includes:

[0099] Formula (8)

[0100] in, Indicates Moment The direct-axis voltage component of the fundamental voltage vector, Indicates the electrical angle, Indicates Moment The switching function of the basic voltage vector, Indicates the inverter voltage.

[0101] In this embodiment, the calculation formula of the quadrature-axis voltage component includes:

[0102] Formula (9)

[0103] in, Indicates Moment The quadrature-axis voltage components of the basic voltage vectors, Indicates the electrical angle, Indicates Moment The switching function of the basic voltage vector, Indicates the inverter voltage.

[0104] Based on the direct-axis voltage component, the quadrature-axis voltage component, the direct-axis current feedback value and the quadrature-axis current feedback value, the direct-axis current increment of the motor stator and the quadrature-axis current increment of the motor stator are predicted.

[0105] In this embodiment, the calculation formula of the direct-axis current increment includes:

[0106] Formula (10)

[0107] in, represents the direct axis current increment, represents the sampling period, represents the direct-axis inductance of the motor stator, represents the motor stator resistance, Indicates The predicted value of the direct axis current at time Indicates the synchronous speed of the motor rotor. represents the quadrature-axis inductance of the motor stator, Indicates The predicted value of the quadrature axis current at time Indicates Moment The direct-axis voltage component of the basic voltage vector.

[0108] In this embodiment, the calculation formula of the quadrature-axis current increment includes:

[0109] Formula (11)

[0110] in, represents the quadrature axis current increment, represents the sampling period, represents the quadrature-axis inductance of the motor stator, represents the motor stator resistance, Indicates The predicted value of the quadrature axis current at time Indicates the synchronous speed of the motor rotor. represents the direct-axis inductance of the motor stator, Indicates The predicted value of the direct axis current at time represents the permanent magnet flux, Indicates Moment The quadrature-axis voltage component of the first basic voltage vector.

[0111] The sum of the direct-axis current feedback value and the direct-axis current increment is used as the direct-axis current prediction value of the motor stator at the next moment, and the sum of the quadrature-axis current feedback value and the quadrature-axis current increment is used as the quadrature-axis current prediction value of the motor stator at the next moment.

[0112] In this embodiment, the calculation formula of the direct axis current prediction value includes:

[0113] Formula (12)

[0114] in, Indicates the next moment ( The predicted value of the direct-axis current at time Indicates the current moment ( The direct-axis current feedback value at the moment, Represents the direct-axis current increment.

[0115] In this embodiment, the calculation formula of the quadrature-axis current prediction value includes:

[0116] Formula (13)

[0117] in, Indicates the next moment ( The predicted value of the quadrature-axis current at time Indicates the current moment ( The quadrature-axis current feedback value at the moment Represents the quadrature-axis current increment.

[0118] The cost value of the basic voltage vector is determined based on the correction result, the direct-axis current prediction value, the quadrature-axis current prediction value, and the preset basic voltage vector switching function.

[0119] In this embodiment, the calculation formula of the cost value of the basic voltage vector includes:

[0120] Formula (14)

[0121] in, Indicates The cost of a basic voltage vector, Indicates the given value of direct-axis current, Indicates The predicted value of the direct axis current at time Indicates the given value of the quadrature-axis current, Indicates The predicted value of the quadrature axis current at time Indicates Moment The switching function of the basic voltage vector, Indicates Moment The switching function of the basic voltage vector, Indicates the weight value of the number of switches, Represents the magnitude of the fundamental voltage vector.

[0122] In this embodiment, the quadrature-axis current given value is 0, and the calculation formula of the direct-axis current given value is as follows:

[0123] Formula (15)

[0124] in, Indicates the given value of direct-axis current, Indicates the motor stator current amplitude, Indicates the frequency of the given value of the direct-axis current.

[0125] In this embodiment, the given value of the direct-axis current is expressed in the form of a sinusoidal signal, which can enable the six insulated gate bipolar transistors in the inverter to be alternately turned on, avoiding the technical problem of rapid heating caused by the continuous conduction of the three insulated gate bipolar transistors in the inverter when the direct-axis current is DC, thereby extending the static heating time.

[0126] In one embodiment of the present application, before estimating the stator resistance of the motor, the heating control method includes:

[0127] During the operation of the motor stator, different temperatures of the motor stator and the heat generation power of the motor stator at different temperatures are measured.

[0128] In this embodiment, the measurement range of the motor stator temperature is -20℃-80℃, the motor stator temperature is measured with ΔT℃ as the step size, and each temperature measurement point is used as the working point of the motor stator to measure the heat generation power of the motor stator at each working point. P 1, P 2… P j , j = Round (100 / ΔT), Round () indicates rounding, and ΔT℃ is set according to actual conditions. The smaller the ΔT step is, the more accurate the fitting of power and temperature is.

[0129] Different temperatures and heating powers at different temperatures are fitted to obtain the relationship between the motor stator temperature and heating power.

[0130] In this embodiment, the method for fitting different temperatures and the heating powers at different temperatures adopts the least square method, the minimum residual method, the polynomial fitting method, etc.

[0131] Based on the mapping relationship between the heating power and the motor stator resistance and the relationship between the motor stator temperature and the heating power, a target mapping relationship is determined.

[0132] In this embodiment, when the motor is stalled, all the heat generation power of the motor comes from thermal power, and there is no mechanical power. Therefore, it can be obtained that the calculation formula of the heat generation power in the motor stalling stage is:

[0133] Formula (16)

[0134] in, Indicates the heat generation power of the motor stator during the stall phase. Indicates the AC current amplitude of the motor stator in the stall stage, Indicates the wire resistance.

[0135] Similarly, the stator resistance of the motor at a certain working point in the motor stall phase can be obtained. The expression of the stator resistance of the motor at a certain working point is as follows:

[0136] Formula (17)

[0137] in, Indicates a working point The stator resistance of the motor at , where , Indicates that at a certain working point The heating power at Indicates the AC current amplitude of the motor stator during the stall stage.

[0138] In this embodiment, formula (16) represents the mapping relationship between the heating power and the stator resistance of the motor.

[0139] In this embodiment, after obtaining the mapping relationship between the heating power and the motor stator resistance and the relationship between the motor stator temperature and the heating power, the target mapping relationship is obtained by polynomial fitting. The expression of the target mapping relationship includes:

[0140] Formula (18)

[0141] in, Indicates the internal resistance of the motor stator. Indicates the motor stator temperature, Indicates the motor stator resistance when the motor stator temperature is 25°C. represents the highest order of fit, a 1, a 2… a m , a represents the polynomial fit coefficients.

[0142] In this embodiment, after the motor stator temperature is obtained, the estimated value of the motor stator internal resistance can be obtained through the target mapping relationship, thereby achieving indirect estimation of the motor stator power feedback value.

[0143] In one embodiment of the present application, the process of setting the motor stator heating power and the motor stator current amplitude based on the temperature of the target component includes:

[0144] Based on the comparison result between the temperature of the target component and the second preset temperature threshold, the working gear of the motor stator is determined.

[0145] In this embodiment, the second preset temperature threshold is less than the first preset temperature threshold. The process of determining the working gear of the motor stator includes: (1) if the temperature of the target component is less than the first preset temperature threshold and the temperature of the target component is greater than or equal to the second preset temperature threshold, the working gear of the motor stator is set to gear 1; (2) if the temperature of the target component is less than the second preset temperature threshold, the working gear of the motor stator is set to gear 2, and the motor stator heating power given in gear 2 is higher than the motor stator heating power given in gear 1.

[0146] According to the working gear, the motor stator heating power and the motor stator current amplitude are given.

[0147] In this embodiment, taking the working gears 1 and 2 as an example, the motor stator heating power given in gear 1 is 3.5kw, and the motor stator current amplitude given in gear 1 is 200A. The motor stator heating power given in gear 2 is 4.5kw, and the motor stator current amplitude given in gear 2 is 227A.

[0148] In this embodiment, the motor stator heating power value and the motor stator current amplitude given for each gear are set according to actual conditions, and are not listed one by one here.

[0149] Figure 3 is a flow chart of the motor working process shown in an exemplary embodiment of the present application, such as Figure 3As shown, the motor working process includes: (1) receiving the heating control signal of the upper controller through the heating signal receiving device, the heating control signal includes the heating request, the heating request signal valid flag, the motor stator heating power, the gear signal of the whole vehicle, and the gear valid flag of the whole vehicle. If the heating request signal valid flag is valid and the gear of the whole vehicle is the parking gear, the heating mode is entered. If the heating request signal valid flag is invalid, and / or the gear of the whole vehicle is not the parking gear, the heating mode is not entered. (2) After receiving the signal to enter the heating mode, the electric drive self-test program will be first performed through the motor self-test module to check the current motor state (including but not limited to the motor temperature, the motor controller temperature, the whole vehicle voltage, the temperature and flow of the motor cooling water), and determine whether the current motor state meets the expected requirements. After the self-test is completed, if the current motor state meets the expected requirements, then the gear selection signal is input into the current design strategy module, and after being processed by the current design strategy module, the basic voltage vector with the minimum cost value is output through the output module, and different insulated gate bipolar transistors in the inverter are controlled to be turned on, thereby controlling the motor stator to heat.

[0150] In this embodiment, the expected requirement of the current motor state is set according to actual conditions, and no specific limitation is made here.

[0151] In this embodiment, the current design strategy module includes a power closed-loop correction module and a current loop control module.

[0152] Figure 4 is a schematic diagram of a power closed-loop correction module shown in an exemplary embodiment of the present application, such as Figure 4 As shown, after receiving the gear selection signal, the working gear of the motor stator is determined based on the comparison result of the temperature of the target component and the second preset temperature threshold. After determining the working gear, the motor stator heating power is obtained by looking up the table, and the motor stator current amplitude is further looked up according to the motor stator heating power. According to the motor stator temperature, the motor stator resistance is obtained by looking up the table, and then the motor stator power feedback value is obtained according to the motor stator current amplitude and the motor stator resistance. Then, the motor stator heating power is subtracted from the motor stator power feedback value to obtain the power error, and then the power error is adjusted by the PI controller to obtain the current amplitude correction value, and finally the difference between the motor stator current amplitude and the current amplitude correction value is used as the correction result.

[0153] In this embodiment, there are three working gears, namely, the motor stator heating power given in gear 1 is 3.5kW, the motor stator heating power given in gear 2 is 4.5kW, and the motor stator heating power given in gear 3 is 5.5kW. The motor stator current amplitude given in gear 1 is 200A, the motor stator current amplitude given in gear 2 is 227A, and the motor stator current amplitude given in gear 3 is 250A.

[0154] In this embodiment, in order to accurately obtain the temperature rise characteristic curve of the motor stator resistance, the motor stator heating power from -20°C to 80°C is recorded with a step size of 2°C. At the same time, in order to avoid the fitting error caused by the motor stator current, the three gears are tested separately to obtain the first gear motor stator resistance-motor stator temperature lookup table (temperature-resistance table), the second gear motor stator resistance-motor stator temperature lookup table, and the third gear motor stator resistance-motor stator temperature lookup table.

[0155] In this embodiment, based on the comparison result of the temperature of the target component and the second preset temperature threshold, the process of determining the working gear of the motor stator includes: (1) if the temperature of the target component is less than the first preset temperature threshold and the temperature of the target component is greater than or equal to the second preset temperature threshold, the working gear of the motor stator is set to gear 1; (2) if the temperature of the target component is less than the second preset temperature threshold and the temperature of the target component is greater than or equal to the third preset temperature threshold, the working gear of the motor stator is set to gear 2; (3) if the temperature of the target component is less than the third preset temperature threshold, the working gear of the motor stator is set to gear 3.

[0156] Figure 5 is a schematic diagram of a current loop control module shown in an exemplary embodiment of the present application, such as Figure 5 As shown, the correction result is input into the trigonometric function for calculation to obtain the given direct-axis current value of the motor stator and the given quadrature-axis current value of the motor stator, and finally sent to the (Model Predictive Control, MPC) model predictive control for current loop control. The mechanical angle of the motor rotor is detected by the resolver sensor, and the electrical angle is obtained by multiplying the mechanical angle of the motor rotor by the number of motor pole pairs. Based on the electrical angle, the preset basic voltage vector switching function, and the inverter voltage, the direct-axis voltage component and the quadrature-axis voltage component of the 8 basic voltage vectors can be obtained, where n represents the nth basic voltage vector. Based on the direct-axis voltage component, the quadrature-axis voltage component, the direct-axis current feedback value, and the quadrature-axis current feedback value, the direct-axis current increment of the motor stator and the quadrature-axis current increment of the motor stator are predicted. The motor stator input current (three-phase current i a , i b , i c ) is transformed into the two-phase input current in the synchronous rotating coordinate system ( i alpha , i beta ), then, the two-phase input current ( i alpha , i beta)After Clark transformation, the direct axis current feedback value of the motor stator at the current moment is obtained i d And the quadrature axis current feedback value of the motor stator at the current moment i q The sum of the direct-axis current feedback value and the direct-axis current increment is used as the direct-axis current prediction value of the motor stator at the next moment. i dk+1 The sum of the quadrature-axis current feedback value and the quadrature-axis current increment is used as the quadrature-axis current prediction value of the motor stator at the next moment. i qk+1 . Based on the given direct-axis current value, the given quadrature-axis current value, the predicted direct-axis current value, the predicted quadrature-axis current value, and the preset basic voltage vector switching function, the cost value of the basic voltage vector is determined and stored. The cost values ​​of the eight basic voltage vectors in the inverter are compared, and the basic voltage vector with the smallest value is replaced as the voltage output terminal. The switching signal corresponding to the basic voltage vector with the smallest cost value turns on the insulated gate bipolar transistor (IGBT) and outputs voltage, thereby generating heat in the motor stator.

[0157] It should be noted that the weight of the number of switching times in formula (14) is α It should not be too large or too small. The weight of the number of switches α Too large, the number of switches is not optimized significantly, and the weight of the number of switches α If it is too small, the harmonic content of the motor stator current will be large and it needs to be calibrated based on the actual situation to get the optimal value.

[0158] In this embodiment, the inverter is a three-phase inverter, which consists of three bridge arms. Each bridge arm has two switching devices. For each bridge arm, it is defined as "1" when the upper bridge arm switch is turned on, and it is defined as "0" when the lower bridge arm switch is turned on. Since there are three bridge arms, the switching state of the entire inverter can be represented by a three-bit binary number, such as "100", "010", etc., that is, there are 8 switching states in total, and these 8 switching state combinations are used as basic voltage vectors.

[0159] Figure 6 FIG. 1 is an exemplary embodiment of the present application showing the current following condition of the direct-quadrature axis when the current loop control module adopts the proportional-integral control algorithm, such as Figure 6 As shown, Indicates the given value of direct-axis current, Indicates the given value of the quadrature-axis current, Represents the direct-axis current feedback value, Represents the quadrature-axis current feedback value. When the current loop control module adopts the proportional-integral control algorithm, the change of the direct-axis current feedback value is consistent with the change of the direct-axis current set value, and the change of the quadrature-axis current feedback value is consistent with the change of the quadrature-axis current set value. Therefore, the direct-axis-quadrature current following condition is better.

[0160] Figure 7 1 is an exemplary embodiment of the present application showing the switching condition of the inverter when the current loop control module adopts the proportional integral control algorithm, which is represented by a black bar graph during the inverter shutdown process. Figure 7 As shown, when the current loop control module adopts the proportional-integral control algorithm, due to the high switching frequency of the inverter, multiple black bar graphs overlap during the inverter shutdown process. Therefore, each inverter shutdown process cannot be clearly displayed.

[0161] Figure 8 FIG. 1 is an exemplary embodiment of the present application showing the current following condition of the direct-quadrature axis when the current loop control module adopts the model predictive control algorithm, such as Figure 8 As shown, Indicates the given value of direct-axis current, Indicates the given value of the quadrature-axis current, Represents the direct-axis current feedback value, Represents the quadrature-axis current feedback value. When the current loop control module adopts the proportional-integral control algorithm, the change of the direct-axis current feedback value is consistent with the change of the direct-axis current set value, and the change of the quadrature-axis current feedback value is consistent with the change of the quadrature-axis current set value. Therefore, the direct-axis-quadrature current following condition is better.

[0162] Fig. 9 1 is an exemplary embodiment of the present application showing the switching condition of the inverter when the current loop control module adopts the model predictive control algorithm, which is represented by a black bar graph during the inverter shutdown process. Fig. 9 As shown, when the current loop control module adopts the model predictive control algorithm, the switching status of the inverter is clearly visible. In the same time period, the switching times of the inverter are reduced by about 40%, which means that the inverter loss is smaller and the heating efficiency is higher. In addition, fewer switching times of the inverter means that the temperature rise of the inverter is smaller, and the heat generation and heating rate of the motor stator can be increased by injecting a current with a larger amplitude.

[0163] Fig.10 is a heating power waveform diagram of the motor stator when the power closed-loop correction module is not used, as shown in an exemplary embodiment of the present application. Fig.10It can be seen that if the motor stator resistance changes greatly, the motor stator heating power will also shift accordingly (floating around 3.5kw), with a maximum shift of 2kW. If the selected heating gear increases, the motor stator heating power shift will increase further. Moreover, the positive direction shift of the motor stator heating power may cause the motor to overheat and affect the motor life.

[0164] Fig.11 is a heating power waveform diagram of the motor stator when a power closed-loop correction module is used, as shown in an exemplary embodiment of the present application. Fig.11 It can be seen that the maximum deviation of the motor stator heating power (the difference between the motor stator heating power and the power of 3.5kW) is less than 0.08kW, and the accuracy of the motor stator heating power is significantly improved. The reduction of the deviation of the motor stator heating power means that the motor stator heating power is less affected by the motor stator resistance temperature, so the motor stator temperature can be guaranteed to be within the safety threshold.

[0165] Fig.12 is a direct-axis current waveform diagram shown in an exemplary embodiment of the present application, such as Fig.12 As shown, since the given value of the direct-axis current is a sine wave, it can be deduced based on the voltage equation of the motor that in steady state, the fundamental wave of the direct-axis voltage must also be a sine wave. The fundamental wave expression of the direct-axis voltage is as follows:

[0166] Formula (19)

[0167] in, represents the fundamental wave of the direct axis voltage, A is the direct axis voltage amplitude, is the synchronous speed of the motor rotor in steady state, is the fundamental phase of the direct-axis voltage.

[0168] At the same time, since the given value of the quadrature axis current is zero, the quadrature axis voltage is basically 0. After the fundamental wave of the direct axis voltage undergoes Park inverse transformation and Clark inverse transformation, the three-phase voltage of the direct axis voltage in the three-phase stationary coordinate system can be obtained. The expression of the three-phase voltage is as follows:

[0169] Formula (20)

[0170] in, Indicates one phase voltage, Indicates the fundamental wave of the direct-axis voltage.

[0171] Formula (21)

[0172] in, Indicates one phase voltage, represents the fundamental wave of the direct-axis voltage, Indicates electrical angle.

[0173] Formula (22)

[0174] in, Indicates one phase voltage, represents the fundamental wave of the direct-axis voltage, Indicates electrical angle.

[0175] Due to static heating of the car, the motor is in a stalled state, and the electrical angle It is fixed as a constant value, and for the convenience of analysis, it is assumed that the electrical angle is 0. It can be obtained that the fundamental amplitude expression of the three-phase voltage is:

[0176] Formula (23)

[0177] in, represents one phase voltage, A is the direct axis voltage amplitude, is the synchronous speed of the motor rotor in steady state, is the fundamental phase of the direct-axis voltage.

[0178] Formula (24)

[0179] in, represents one phase voltage, A is the direct axis voltage amplitude, is the synchronous speed of the motor rotor in steady state, is the fundamental phase of the direct-axis voltage.

[0180] Formula (25)

[0181] in, represents one phase voltage, A is the direct axis voltage amplitude, is the synchronous speed of the motor rotor in steady state, is the fundamental phase of the direct-axis voltage.

[0182] Formula (23) to Formula (25) show that when the direct-axis current is a sinusoidal current, the three-phase voltage of the motor stator will also generate a sinusoidal voltage of the same frequency, in which the amplitude and phase of the two-phase voltage are exactly the same, which is half of the other phase voltage, and the phase of the two-phase voltage with a smaller amplitude is 180° different from the phase of the other phase voltage. The above analysis shows that when the direct-axis current adopts a sinusoidal current, the six insulated gate bipolar transistors of the inverter will be turned on alternately, avoiding the problem that when the direct-axis current adopts a constant current, the on-off is concentrated on the fixed three insulated gate bipolar transistors, resulting in the problem of rapid heating of the inverter, thereby extending the static heating time.

[0183] In this embodiment, the voltage equation of the motor is as follows:

[0184] Formula (26)

[0185] in, represents the direct axis voltage of the motor stator in the synchronous rotating coordinate system, represents the motor stator resistance, represents the direct axis current of the motor stator in the synchronous rotating coordinate system, represents the direct-axis inductance of the motor stator, Indicates the synchronous speed of the motor rotor. represents the quadrature-axis inductance of the motor stator, represents the quadrature-axis current of the motor stator in the synchronous rotating coordinate system, represents the quadrature axis voltage of the motor stator in the synchronous rotating coordinate system, Represents the flux linkage of a permanent magnet.

[0186] Fig.13 is a flow chart of a heating control method shown in another exemplary embodiment of the present application, such as Fig.13 As shown, the heating control method includes: (1) receiving a heating control signal and obtaining a power battery temperature; (2) determining whether the power battery temperature meets a heating condition. If the power battery temperature does not meet the heating condition, the heating mode is not entered; if the power battery temperature meets the heating condition, the heating mode is entered, and based on a comparison result between the temperature of the target component and a second preset temperature threshold, the working gear of the motor stator is determined; (3) after determining the working gear, the motor stator current amplitude is selected according to the working gear; (4) based on the motor stator current amplitude and the motor stator current amplitude, the motor stator current amplitude is selected. Resistance, estimate the motor stator power feedback value; (5) input the difference between the motor stator heating power and the motor stator power feedback value into the power closed-loop correction module to correct the motor stator current amplitude; (6) determine the cost value of the basic voltage vector through the current loop control module based on the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter; (7) use the basic voltage vector with the smallest cost value as the voltage output terminal to control the conduction of different insulated gate bipolar transistors in the inverter and output the working current of the motor stator.

[0187] In this embodiment, if the power battery temperature is less than the first preset temperature threshold, it is determined that the power battery temperature meets the heating condition; if the power battery temperature is greater than or equal to the first preset temperature threshold, it is determined that the power battery temperature does not meet the heating condition.

[0188] The following describes an embodiment of the device of the present application, which can be used to execute the heating control method in the above embodiment of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the heating control method in the above embodiment of the present application.

[0189] Fig.14 is a block diagram of a heating control device shown in an exemplary embodiment of the present application. The device can be applied to Figure 1 The implementation environment shown is specifically configured in the vehicle controller 102. The device may also be applicable to other exemplary implementation environments and specifically configured in other devices. This embodiment does not limit the implementation environment to which the device is applicable.

[0190] like Fig.14 As shown, the exemplary heating control device includes:

[0191] The temperature acquisition module 1401 is used to acquire the temperature of the target component inside the vehicle, the motor stator temperature, and the motor stator input current.

[0192] The current correction module 1402 is used to give the motor stator heating power and the motor stator current amplitude based on the temperature of the target component if the temperature of the target component is less than the first preset temperature threshold, and estimate the motor stator resistance based on the motor stator temperature and the target mapping relationship, and correct the motor stator current amplitude in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power.

[0193] The cost determination module 1403 is used to transform the motor stator input current to obtain the direct-axis current feedback value of the motor stator and the quadrature-axis current feedback value of the motor stator at the current moment; and determine the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter.

[0194] The conduction control module 1404 is used to use the basic voltage vector with the minimum cost value as the voltage output terminal to control the conduction of different insulated gate bipolar transistors in the inverter to control the motor stator to heat the target component.

[0195] In one embodiment of the present application, the temperature of the target component and the motor stator temperature are acquired by temperature sensors, etc., and the motor stator input current is acquired by current sensors, etc. The target components include but are not limited to power batteries, seats, rearview mirrors, and windshields.

[0196] In this embodiment, considering the heating demand inside the vehicle, the target area may also be heated, and the target area includes but is not limited to the vehicle cabin.

[0197] In this embodiment, the first preset temperature threshold needs to be set according to actual conditions and is not specifically limited here.

[0198] In this embodiment, the target mapping relationship is used to characterize the relationship between the motor stator temperature and the motor stator resistance. The process of calibrating the target mapping relationship includes: (1) measuring different temperatures of the motor stator and the heat generation power of the motor stator at different temperatures during the operation of the motor stator; (2) fitting different temperatures and heat generation powers at different temperatures to obtain the relationship between the motor stator temperature and the heat generation power; (3) determining the target mapping relationship based on the mapping relationship between the heat generation power and the motor stator resistance and the relationship between the motor stator temperature and the heat generation power.

[0199] In this embodiment, after obtaining the motor stator temperature, the motor stator resistance is determined according to the change data of the motor stator resistance with the motor stator temperature, and the motor stator power feedback value is estimated according to the motor stator current amplitude and the motor stator resistance. Based on the difference between the motor stator heating power and the motor stator power feedback value, the motor stator current amplitude is corrected in real time to improve the accuracy of the motor stator heating power output, which is conducive to keeping the heating power constant.

[0200] In this embodiment, the process of determining the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter includes: (1) obtaining the number of motor pole pairs, the mechanical angle of the motor rotor, and the inverter voltage; (2) taking the product of the number of motor pole pairs and the mechanical angle of the motor rotor as the electrical angle; (3) determining the direct-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the electrical angle, the preset basic voltage vector switching function, and the inverter voltage; (4) determining the direct-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the direct-axis current feedback value and the quadrature-axis current feedback value of the inverter; and (5) determining the quadrature-axis voltage component and the quadrature-axis voltage component of the basic voltage vector based on the direct-axis current feedback value and the quadrature-axis current feedback value of the inverter. The direct-axis voltage component, the quadrature-axis voltage component, the direct-axis current feedback value and the quadrature-axis current feedback value are used to predict the direct-axis current increment and the quadrature-axis current increment of the motor stator; (5) the sum of the direct-axis current feedback value and the direct-axis current increment is used as the direct-axis current prediction value of the motor stator at the next moment, and the sum of the quadrature-axis current feedback value and the quadrature-axis current increment is used as the quadrature-axis current prediction value of the motor stator at the next moment; (6) based on the correction result, the direct-axis current prediction value, the quadrature-axis current prediction value and the preset basic voltage vector switching function, the cost value of the basic voltage vector is determined.

[0201] In this embodiment, the basic voltage vector with the smallest substitution value is selected as the voltage output terminal, which reduces the switching times of the inverter, reduces the temperature rise of the inverter, and improves the conversion efficiency and service life of the inverter.

[0202] It should be noted that the heating control device provided in the above embodiment and the heating control method provided in the above embodiment belong to the same concept, wherein the specific manner in which each module and unit performs the operation has been described in detail in the method embodiment, and will not be repeated here. In practical applications, the heating control device provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0203] An embodiment of the present application also provides a vehicle-mounted device, including: one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by one or more processors, the vehicle-mounted device implements the heating control method provided in the above-mentioned embodiments.

[0204] According to one aspect of an embodiment of the present application, a vehicle is provided, the vehicle including the apparatus provided in the above-mentioned embodiments or the vehicle-mounted equipment provided in the above-mentioned embodiments.

[0205] Fig.15 The structure diagram of the computer system of the vehicle-mounted device suitable for implementing the embodiment of the present application is shown. It should be noted that: Fig.15 The computer system of the vehicle-mounted device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0206] like Fig.15 As shown, the computer system 1500 includes a central processing unit (CPU) 1501, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 1502 or the program loaded from the storage part 1508 to the random access memory (RAM) 1503, such as executing the method in the above embodiment. In the RAM 1503, various programs and data required for system operation are also stored. The CPU 1501, the ROM 1502 and the RAM 1503 are connected to each other through the bus 1504. The input / output (I / O) interface 1505 is also connected to the bus 1504.

[0207] The following components are connected to the I / O interface 1505: an input section 1506 including a keyboard, a mouse, etc.; an output section 1507 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 1508 including a hard disk, etc.; and a communication section 1509 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 1509 performs communication processing via a network such as the Internet. A drive 1510 is also connected to the I / O interface 1505 as needed. A removable medium 1511, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 1510 as needed so that a computer program read therefrom is installed into the storage section 1508 as needed.

[0208] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 1509, and / or installed from a removable medium 1511. When the computer program is executed by the central processing unit (CPU) 1501, various functions defined in the system of the present application are executed.

[0209] It should be noted that the computer-readable medium shown in the embodiment of the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier, which carries a computer-readable computer program. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. A computer program contained on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0210] The flowchart and block diagram in the accompanying drawings illustrate the possible architecture, functions and operations of the system, method and computer program product according to various embodiments of the present application. Wherein, each box in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0211] The units involved in the embodiments described in this application may be implemented by software or hardware, and the units described may also be set in a processor. The names of these units do not, in some cases, constitute limitations on the units themselves.

[0212] Another aspect of the present application provides a computer-readable storage medium on which computer-readable instructions are stored. When the computer-readable instructions are executed by a processor of a computer, the computer executes the heating control method provided in each of the above embodiments. The computer-readable storage medium may be included in the vehicle-mounted device described in the above embodiments, or may exist independently without being assembled into the vehicle-mounted device.

[0213] It should be noted that, although several modules or units of the equipment for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into being embodied by multiple modules or units.

[0214] Through the description of the above implementation methods, it is easy for those skilled in the art to understand that the example implementation methods described here can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the implementation methods of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the implementation methods of the present application.

[0215] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0216] It should be understood that the above content is only a preferred exemplary embodiment of the present application and is not intended to limit the implementation scheme of the present application. Ordinary technicians in this field can easily make corresponding changes or modifications based on the main concept and spirit of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection required by the claims.

Claims

1. A heating control method, characterized in that: The heating control method comprises: Acquiring the temperature of a target component inside the vehicle, the temperature of a motor stator, and the input current of the motor stator, wherein the target component includes a power battery; If the temperature of the target component is less than a first preset temperature threshold, based on the temperature of the target component, the motor stator heating power and the motor stator current amplitude are given, the motor stator resistance is estimated based on the motor stator temperature and the target mapping relationship, and the motor stator current amplitude is corrected in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power; the target mapping relationship is used to characterize the relationship between the motor stator temperature and the motor stator resistance; The motor stator input current is transformed to obtain a direct-axis current feedback value of the motor stator at the current moment and a quadrature-axis current feedback value of the motor stator at the current moment; and a cost value of the basic voltage vector is determined according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and a preset basic voltage vector switching function of the inverter; Using the basic voltage vector with the minimum cost value as a voltage output terminal, controlling different insulated gate bipolar transistors in the inverter to conduct, so as to control the motor stator to heat the target component; The process of determining the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter includes: Obtain the number of motor pole pairs, motor rotor mechanical angle, and inverter voltage; The product of the number of motor pole pairs and the mechanical angle of the motor rotor is used as the electrical angle; Determine a direct-axis voltage component of a basic voltage vector and a quadrature-axis voltage component of a basic voltage vector based on the electrical angle, the preset basic voltage vector switching function, and the inverter voltage; Predicting a direct-axis current increment of the motor stator and a quadrature-axis current increment of the motor stator based on the direct-axis voltage component, the quadrature-axis voltage component, the direct-axis current feedback value, and the quadrature-axis current feedback value; Taking the sum of the direct-axis current feedback value and the direct-axis current increment as the direct-axis current prediction value of the motor stator at the next moment, and taking the sum of the quadrature-axis current feedback value and the quadrature-axis current increment as the quadrature-axis current prediction value of the motor stator at the next moment; The cost value of the basic voltage vector is determined based on the correction result, the direct-axis current prediction value, the quadrature-axis current prediction value, and the preset basic voltage vector switching function.

2. The heating control method according to claim 1, characterized in that: The process of correcting the motor stator current amplitude in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power includes: estimating a motor stator power feedback value based on the motor stator current amplitude and the motor stator resistance; The difference between the motor stator heating power and the motor stator power feedback value is taken as the power error; Adjusting the power error to obtain a current amplitude correction value; The difference between the motor stator current amplitude and the current amplitude correction value is taken as the correction result.

3. The heating control method according to claim 1, characterized in that: The process of transforming the motor stator input current to obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment includes: Converting the motor stator input current into a two-phase input current; The two-phase input current is rotationally transformed to obtain a direct-axis current feedback value of the motor stator at the current moment and a quadrature-axis current feedback value of the motor stator at the current moment.

4. The heating control method according to claim 1, characterized in that: If the correction result includes the given value of the direct-axis current of the motor stator and the given value of the quadrature-axis current of the motor stator, the calculation formula of the cost value of the basic voltage vector includes: ， in, Indicates The cost of a basic voltage vector, Indicates the given value of direct-axis current, Indicates The predicted value of the direct axis current at time Indicates the given value of the quadrature axis current, Indicates The predicted value of the quadrature axis current at time Indicates Moment The switching function of the basic voltage vector, Indicates Moment The switching function of the basic voltage vector, Indicates the weight value of the number of switches, Represents the magnitude of the basic voltage vector, and the direct-axis current given value is expressed in the form of a sinusoidal signal.

5. The heating control method according to claim 1, characterized in that: The calculation formula of the direct axis voltage component includes: ， in, Indicates Moment The direct-axis voltage component of the fundamental voltage vector, Indicates the electrical angle, Indicates Moment The switching function of the basic voltage vector, Indicates the inverter voltage; The calculation formula of the quadrature axis voltage component includes: ， in, Indicates Moment The quadrature-axis voltage components of the basic voltage vectors, Indicates the electrical angle, Indicates Moment The switching function of the basic voltage vector, Indicates the inverter voltage.

6. The heating control method according to claim 1, characterized in that: The calculation formula of the direct axis current increment includes: ， in, represents the direct axis current increment, represents the sampling period, represents the direct-axis inductance of the motor stator, represents the motor stator resistance, Indicates The predicted value of the direct axis current at time Indicates the synchronous speed of the motor rotor. represents the quadrature-axis inductance of the motor stator, Indicates The predicted value of the quadrature axis current at time Indicates Moment The direct-axis voltage component of the basic voltage vector; The calculation formula of the quadrature-axis current increment includes: ， in, represents the quadrature axis current increment, represents the sampling period, represents the quadrature-axis inductance of the motor stator, represents the motor stator resistance, Indicates The predicted value of the quadrature axis current at time Indicates the synchronous speed of the motor rotor. represents the direct-axis inductance of the motor stator, Indicates The predicted value of the direct axis current at time represents the permanent magnet flux, Indicates Moment The quadrature-axis voltage component of the first basic voltage vector.

7. The heating control method according to any one of claims 1 to 6, characterized in that: Before estimating the motor stator resistance, the heating control method includes: During the operation of the motor stator, measuring different temperatures of the motor stator and the heating power of the motor stator at different temperatures; Fit different temperatures and heating powers at different temperatures to obtain the relationship between the motor stator temperature and heating power; The target mapping relationship is determined based on a mapping relationship between heating power and motor stator resistance and a relationship between motor stator temperature and heating power.

8. The heating control method according to any one of claims 1 to 6, characterized in that: Based on the temperature of the target component, the process of giving the motor stator heating power and the motor stator current amplitude includes: Determining the working gear of the motor stator based on a comparison result of the temperature of the target component and a second preset temperature threshold; the second preset temperature threshold is less than the first preset temperature threshold; According to the working gear, the motor stator heating power and the motor stator current amplitude are given.

9. A heating control device, characterized in that: The heating control device is used to execute the heating control method according to any one of claims 1 to 8, and the heating control device comprises: A temperature acquisition module, used to acquire the temperature of a target component inside the vehicle, the temperature of a motor stator, and the input current of a motor stator, wherein the target component includes a power battery; A current correction module, for, if the temperature of the target component is less than a first preset temperature threshold, then based on the temperature of the target component, a given motor stator heating power and a motor stator current amplitude are given, based on the motor stator temperature and a target mapping relationship, estimating the motor stator resistance, and correcting the motor stator current amplitude in combination with the motor stator current amplitude, the motor stator resistance, and the motor stator heating power; the target mapping relationship is used to characterize the relationship between the motor stator temperature and the motor stator resistance; A cost determination module is used to transform the motor stator input current to obtain the direct-axis current feedback value of the motor stator at the current moment and the quadrature-axis current feedback value of the motor stator at the current moment; and determine the cost value of the basic voltage vector according to the correction result, the direct-axis current feedback value, the quadrature-axis current feedback value, and the preset basic voltage vector switching function of the inverter; The conduction control module is used to use the basic voltage vector with the minimum cost value as the voltage output terminal to control the conduction of different insulated gate bipolar transistors in the inverter to control the motor stator to heat the target component.

10. A vehicle-mounted device, characterized in that: include: one or more processors; A storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, enables the vehicle-mounted device to implement the heating control method as described in any one of claims 1 to 8.

11. A vehicle, characterized in that: The vehicle comprises the apparatus according to claim 9 or the vehicle-mounted device according to claim 10.

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