CN116278788A

CN116278788A - Motor controller, power system, vehicle and heating method of power battery

Info

Publication number: CN116278788A
Application number: CN202211658503.9A
Authority: CN
Inventors: 马国龙; 朱明�; 曹金满; 赵成; 邹强
Original assignee: Beijing Jidu Technology Co Ltd
Current assignee: Beijing Jidu Technology Co Ltd
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2023-06-23

Abstract

The application provides a motor controller, a power system, a vehicle and a heating method of a power battery. Wherein, the motor controller includes: the power module is provided with a direct current bus and an alternating current bus, the direct current bus is used for receiving direct current output by the power battery, the power module is used for converting the direct current into alternating current, and the alternating current bus is used for outputting the alternating current to the motor; the control module is connected with the power module and used for sending a first control signal to the power module, the first control signal is used for controlling the power module to input a target square wave voltage to a direct shaft of the motor, the target square wave voltage is a square wave voltage with frequency change and/or amplitude change, the target square wave voltage is used for generating alternating pulse current on a direct current bus, the pulse current is used for heating a power battery, the generation of concentrated radial electromagnetic force in the motor is avoided, and accordingly vibration and noise caused by unbalanced stress in the motor are reduced, and the comfort level of a vehicle is improved.

Description

Motor controller, power system, vehicle and heating method of power battery

Technical Field

The application relates to the field of control, in particular to a motor controller, a power system, a vehicle and a heating method of a power battery.

Background

Currently, some vehicles may be powered by power cells, such as power cars, electric trains, electric bicycles, and the like. However, when the ambient temperature is too low, the performance of the power battery may be affected, for example, the too low ambient temperature may inhibit the discharge capability of the power battery, resulting in a great reduction in the range of the vehicle. Therefore, the power battery is usually heated by direct heating or indirect heating.

In the direct heating mode based on the square wave voltage, the square wave voltage is constant in amplitude and frequency. After the square wave voltage is input to a direct shaft of the motor, concentrated radial electromagnetic force can be generated in the motor, so that magnetic field distribution of the motor during normal operation is affected, internal stress of the motor is unbalanced, vibration and noise are caused, noise, vibration and sound vibration roughness (noise, vibration, harshness, NVM) indexes of a vehicle are reduced, and comfort of the vehicle is reduced.

Disclosure of Invention

Embodiments of the present application are directed to a motor controller, a power system, a vehicle, a heating method for a power battery, and a computer program product. The following description will be made in terms of several aspects.

In a first aspect, there is provided a motor controller comprising: the power module is provided with a direct current bus and an alternating current bus, the direct current bus is used for receiving direct current output by the power battery, the power module is used for converting the direct current into alternating current, and the alternating current bus is used for outputting the alternating current to the motor; the control module is connected with the power module and is used for sending a first control signal to the power module, the first control signal is used for controlling the power module to input a target square wave voltage to a direct shaft of the motor, the target square wave voltage is a square wave voltage with frequency change and/or amplitude change, the target square wave voltage is used for generating alternating pulse current on the direct current bus, and the pulse current is used for heating the power battery.

In one possible implementation, the target square wave voltage is a square wave voltage of constant amplitude and varying frequency.

In one possible implementation, the control module is configured to: receiving current operation parameters of the motor; generating the first control signal according to the current operating parameter and a first voltage reference value sequence of the straight axis, wherein the first voltage reference value sequence comprises a plurality of reference values, and each reference value in the plurality of reference values comprises the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency; the values of the reference value components of the direct-axis voltage amplitude values in the plurality of reference values are equal, and the values of the reference value components of the direct-axis voltage frequency in the plurality of reference values are not identical.

In one possible implementation, the target square wave voltage is a square wave voltage with constant amplitude, and the amplitude U of the target square wave voltage _d Satisfy the following requirements

Wherein U is _dc Represents the voltage of the power battery, R _s Representing the internal resistance of the motor, iq representing the quadrature current of the motor.

In one possible implementation, the target square wave voltage is a square wave voltage with a frequency variation and a magnitude variation.

In one possible implementation, the control module is configured to: receiving current operation parameters of the motor; generating the first control signal according to the current operating parameter and a second voltage reference value sequence of the straight axis, wherein the second voltage reference value sequence comprises a plurality of reference values, and each reference value in the plurality of reference values comprises the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency; the reference value components of the direct-axis voltage amplitude values in the plurality of reference values are not identical, and the reference value components of the direct-axis voltage frequency in the plurality of reference values are not identical.

In one possible implementation, the control module is further configured to: acquiring heating parameters of the power battery and/or a maximum noise threshold of the motor; and determining the second voltage reference value sequence according to the heating parameter and/or the maximum noise threshold value.

In one possible implementation, the heating parameter is used to determine a reference value component of the direct axis voltage amplitude in the second voltage reference value sequence; and/or the maximum noise threshold is used to determine a reference value component of the direct axis voltage frequency and/or a reference value component of the duration of the direct axis voltage frequency in the second sequence of voltage reference values.

In one possible implementation, the maximum amplitude U of the target square wave voltage _max Satisfy the following requirements

In one possible implementation, the frequency of the target square wave voltage varies randomly or periodically; and/or the amplitude of the target square wave voltage is randomly changed or periodically changed.

In one possible implementation, the control module is further configured to: and sending a second control signal to the power module, wherein the second control signal is used for controlling the power module to input target current to a quadrature axis of the motor, and the target current is used for controlling the motor to generate tooth leaning moment.

In a second aspect, there is provided a power system comprising: a power battery, a motor and a motor controller as in any of the implementations of the first aspect, both the power battery and the motor being connected to a power module in the motor controller.

In a third aspect, there is provided a vehicle comprising the power system of the second aspect. In some implementations, the vehicle may include a vehicle.

In a fourth aspect, there is provided a heating method of a power battery, including: a first control signal is sent to a power module of a motor controller, the first control signal is used for controlling the power module to input a target square wave voltage to a direct axis of a motor, the target square wave voltage is a square wave voltage with amplitude changing and/or frequency changing, and the target square wave voltage is used for generating alternating pulse current on the direct current bus; and heating the power battery by using the pulse current.

In a fifth aspect, there is provided a computer program product comprising computer programs/instructions which when executed by a processor implement the method of the respective aspects.

In some implementations, the computer program product includes computer program code that can include computer program code that, when run on a computer, causes the computer to perform the methods of the above aspects.

In other implementations, the computer program product includes a computer readable medium having program code stored thereon, which when run on a computer causes the computer to perform the methods of the above aspects.

In this embodiment of the present application, the control module of the motor controller may send a first control signal to the power module to control the power module to input the target square wave voltage with a frequency change and/or an amplitude change to the direct axis of the motor, where electromagnetic forces generated by the target square wave voltage with a frequency change and/or an amplitude change inside the motor may be distributed in different directions, and electromagnetic forces in different directions may be mutually reduced, so as to help avoid generating concentrated radial electromagnetic forces in the motor, thereby reducing vibration and noise caused by unbalanced stress inside the motor, and helping to improve comfort level of a vehicle.

Drawings

FIG. 1 is a schematic diagram of a power system suitable for use in embodiments of the present application.

Fig. 2 is a schematic diagram of the D-axis and Q-axis in the motor.

Fig. 3 is a schematic diagram of a target square wave voltage according to an embodiment of the present application.

Fig. 4 is a schematic diagram of generating a first control signal according to an embodiment of the present application.

Fig. 5 is a schematic diagram of generating a first control signal and a second control signal in an embodiment of the present application.

Fig. 6 is a schematic diagram of generating a first control signal and a second control signal according to another embodiment of the present application.

Fig. 7 is a schematic diagram of current conversion efficiency when a power cell is heated using a target square wave voltage according to an embodiment of the present application.

Fig. 8 is a schematic flow chart of a heating method of the power battery of the embodiment of the present application.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments.

Some vehicles may currently be powered by power cells, such as power cars, electric trains, electric bicycles, and the like. However, when the ambient temperature is too low, the performance of the power battery may be affected, for example, the too low ambient temperature may inhibit the discharge capability of the power battery, resulting in a great reduction in the range of the vehicle. Therefore, the power battery is generally heated by direct heating or indirect heating in the known technology. The indirect heating mode is understood to be that a heat source is placed outside the power battery for heating. In general, indirect heating means may include, for example, air heating, liquid heating, and heating film heating, etc., which are distinguished by different heating sources. Because the indirect heating mode is to provide heat for the power battery through an external heat source, heat loss can occur on a medium for transmitting heat in the process of transmitting heat, so that the indirect heating efficiency is low.

The direct heating mode is understood to mean heating the power cell inside the power cell. Currently, a relatively common direct heating means includes internal resistance heating. The scheme of internal resistance heating is described below in connection with fig. 1. Referring to fig. 1, the power battery 110 and the motor 130 may be connected through a power module 122 of the motor controller 120, wherein the power module 122 is configured to convert direct current provided by the power battery 110 into alternating current and output the alternating current to the motor 130. In addition, the power module 122 may also convert the ac power output by the motor 130 into dc power and input the dc power to the power battery 110. In this way, a closed loop circuit may be formed between the power cell 110 and the stator windings of the motor 130. Thereafter, current may be input to the motor at the power module 122, and in response to the input of current, stator windings in the motor may store electrical energy input by the power cell 110. In addition, the stator windings may in turn provide ac power to the power cells 110 based on the inductive characteristics of the stator windings. Accordingly, the power battery 110 can be in a charge or discharge cycle state, so that the internal resistance of the power battery 110 generates heat (also called ohmic heat) to heat the power battery 110. Generally, the internal resistance of the power battery 110 is high in a low-temperature environment, and accordingly, the efficiency of heating the power battery 110 is high.

As described above, the power module may not be in a driving state during the process of inputting the alternating current to the motor to realize the heating for the power battery, and thus, it is not desirable that the motor drives the vehicle to travel under the action of the alternating current when inputting the alternating current to the motor. In the prior art, taking a motor as an example of a three-phase motor, alternating current is input to a direct shaft (also called as a d-shaft) of the motor, so that the motor can be prevented from generating driving force (such as driving moment) to drive a vehicle to run. For ease of understanding, the d-axis and q-axis of the motor are described below in connection with fig. 2, wherein the d-axis and q-axis may constitute a coordinate system of the motor that rotates in synchronization with the motor.

Referring to fig. 2, the three-phase motor may include three sets of windings, each indicated by "U, W, V". The q-axis of the motor is also known as the "quadrature axis" and is perpendicular to the direction of the magnetic field generated by the NS-pole magnets in the motor, or the axis that intersects the direction of the magnetic field in the motor. The current and/or voltage in the quadrature axis direction may be used to control the magnitude of the driving force output by the motor. Correspondingly, the d-axis of the motor is also called a direct-axis (direct-axis), which is the same as the direction of the magnetic field generated by the NS-pole magnet in the motor, or is an axis parallel to the direction of the magnetic field in the motor. The current and/or voltage in the direction of the direct axis may be used to control the magnitude of the magnetic field within the motor. Therefore, applying a voltage and/or current in the direction of the straight axis of the motor may change the magnitude of the magnetic field direction within the motor, but does not cause the motor to generate a driving force.

Currently, a control module of a motor controller can input a control signal to a power module to control the power module to input sine wave variable voltage or current to a direct axis of the motor. However, since a voltage or current with a sine wave variation is input to the direct axis of the motor, a larger ripple current is generated on the direct current bus side of the power module, and the ripple current is dissipated by a resistor in the motor controller, the current or voltage flowing to the internal resistance of the power battery through the direct current bus is reduced, the heat generated by the internal resistance in a charge or discharge cycle state is reduced, and the heating efficiency of the power battery is low. If square wave voltage is input to the direct shaft of the motor, ripple current generated on the direct current bus side can be effectively reduced, and current dissipated by a resistor in the power module is reduced, so that current input to the internal resistance of the power battery through the direct current bus is improved, and heating efficiency of the power battery is improved.

However, in the above-described direct heating method based on the square wave voltage, the square wave voltage used is a square wave voltage having a constant amplitude and a constant frequency. After the square wave voltage is input to a direct shaft of the motor, concentrated radial electromagnetic force can be generated in the motor, so that magnetic field distribution of the motor during normal operation is affected, internal stress of the motor is unbalanced, vibration and noise are caused, noise, vibration and sound vibration roughness (noise, vibration, harshness, NVM) indexes of a vehicle are reduced, and comfort of the vehicle is reduced.

Therefore, the embodiment of the application provides a motor controller, wherein a control module can send a first control signal to a power module to control the power module to input a target square wave voltage with frequency variation and/or amplitude variation to a direct axis of a motor, wherein electromagnetic forces generated by the target square wave voltage with frequency variation and/or amplitude variation inside the motor can be distributed to different directions, and the electromagnetic forces in different directions can be mutually reduced, so that the motor controller is beneficial to avoiding the generation of concentrated radial electromagnetic forces in the motor, thereby reducing vibration and noise caused by unbalanced stress inside the motor, and improving the comfort degree of a vehicle.

For ease of understanding, a description of a power system to which embodiments of the present application are applicable is provided below. With continued reference to fig. 1, the power system 100 may include a power battery 110, a motor controller 120 (motor controller unit, MCU), and a motor 130.

A power battery 110 for powering the power system. In some implementations, the power cells may include batteries, such as sealed lead acid batteries employing valve ports, open-cell lead acid batteries, lithium iron phosphate batteries, and the like. Of course, in the embodiment of the present application, the power battery may further include a lithium power battery, a nickel-hydrogen rechargeable battery, and the like, which is not limited in the embodiment of the present application.

The motor controller 120 is used for controlling the motor to work according to the set parameters. In some implementations, the preset parameters may be related to one or more of a direction, a speed, an angle, a response time, etc. of the motor.

In some implementations, the motor controller 120 may include a power module 122 and a control module 121. The power module 122 is used for converting direct current and alternating current. The power module 121 may include a direct current bus and an alternating current bus. Wherein a dc bus may be coupled to the power cell 110 and an ac bus may be coupled to the motor 130. In the embodiment of the present application, the power module 122 may include an inverter circuit, for example.

In some implementations, the control module 121 is used to control the power module 122. For example, the control module 121 may send control signals to the power module 122 to control the voltage and/or current output by the power module. The control signal may be, for example, a pulse width modulation (pulse width modulation, PWM) signal.

And the motor 130 is used for realizing electric energy conversion or transmission according to the law of electromagnetic induction. In some implementations, the motor may be a permanent magnet motor.

The following describes an embodiment of the present application using the motor control 120 in the powertrain 100 shown in fig. 1 as an example. It should be noted that, the motor controller applicable to the embodiment of the present application may also have other structures, for example, may further include a processing unit and the like. The embodiments of the present application are not limited in this regard.

The power module 122 is provided with a direct current bus and an alternating current bus, wherein the direct current bus is used for receiving direct current output by the power battery, the power module is used for converting the direct current into alternating current, and the alternating current bus is used for outputting the alternating current to the motor;

the control module 121 is connected with the power module and is used for sending a first control signal to the power module, the first control signal is used for controlling the power module to input a target square wave voltage to the direct axis of the motor, the target square wave voltage is a square wave voltage with frequency change and/or amplitude change, the target square wave voltage is used for generating alternating pulse current on a direct current bus, and the pulse current is used for heating the power battery.

In some implementations, the target square wave voltage is a square wave voltage of varying frequency and constant amplitude. Of course, in the embodiment of the present application, the target square wave voltage may also be a square wave voltage with a frequency change and an amplitude change. The embodiments of the present application are not limited in this regard.

In this embodiment of the present application, the frequency change may include that the frequency of the target square wave voltage is periodically changed, or that the frequency of the target square wave voltage is randomly changed, and the specific manner of the frequency change is not limited in this embodiment of the present application. In addition, the above-mentioned amplitude variation may include that the amplitude of the target square wave voltage is periodically varied, or that the amplitude of the target square wave voltage is randomly varied, and the specific manner of the amplitude variation is not limited in the embodiments of the present application.

In some implementations, the period of the amplitude variation may be the same as the period of the frequency variation described above. Of course, in the embodiment of the present application, the period of the amplitude variation may be different from the period of the frequency variation. The embodiments of the present application are not limited in this regard.

For ease of understanding, fig. 3 (a) and (b) show schematic diagrams of the target square wave voltage provided by the embodiments of the present application. The target square wave voltage shown in fig. 3 (a) is a square wave voltage whose frequency varies periodically and whose amplitude is constant. Referring to fig. 3 (a), the period of the target square wave voltage may include t ₁₁ 、t ₁₂ 、t ₁₃ 、……t _1n Wherein the period t ₁₁ Less than period t ₁₂ Period t ₁₂ Less than period t ₁₃ … … period t ₁₃ Less than period t _1n . The amplitude of the target square wave voltage in each period can be the same, namely f ₁ 。

The target square wave voltage shown in fig. 3 (b) is a square wave voltage whose frequency varies periodically and whose amplitude varies periodically. Referring to fig. 3 (b), the frequency variation period and the amplitude variation period of the target square wave voltage may include t ₁₁ 、t ₁₂ 、t ₁₃ 、t ₁₄ Wherein the period t ₁₁ Less than period t ₁₂ Period t ₁₂ Less than period t ₁₃ Period t ₁₃ Less than period t ₁₄ . The target square wave voltage is in period t ₁₁ The internal amplitude is f ₁ The target square wave voltage is in period t ₁₂ The internal amplitude is f ₂ The target square wave voltage is in period t ₁₃ The internal amplitude is f ₁ Target square wave voltageIn period t ₁₄ The internal amplitude is f ₂ 。

The manner in which the control module controls the power module to generate the first control signal is described below in connection with modes 1 and 2 based on the different types of target square wave voltages described above.

Mode 1 is described taking a square wave voltage with a constant amplitude and a target square wave voltage as an example.

In some implementations, the control module is configured to: receiving current operation parameters of a motor; and generating a first control signal according to the current operation parameter and a first voltage reference value sequence of the straight shaft.

In some implementations, the current operating parameters of the motor may include one or more of the following: the position of the motor, the speed of the motor, the acceleration of the motor, the stator current of the motor. It should be appreciated that in embodiments of the present application, the current operating parameters described above may be obtained by corresponding sensors on the motor, for example, the position of the motor may be obtained by position sensors. For another example, the speed of the motor may be obtained by a speed sensor.

In some implementations, the first sequence of voltage reference values may include a plurality of reference values, wherein each of the plurality of reference values may include the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency.

In some implementations, the value of the reference value component of the duration of the direct axis voltage frequency may be determined based on the reference value component of the direct axis voltage frequency. For example, the inverse of the value of the reference value component of the direct voltage frequency may be equal to the reference value component of the duration of the direct voltage frequency.

The target square wave voltage is a square wave voltage with a constant amplitude and a variable frequency, so that the values of the reference value components of the amplitude of the direct-axis voltage in the plurality of reference values are equal, and the values of the reference value components of the frequency of the direct-axis voltage in the plurality of reference values are not identical. The values of the reference value components of the direct axis voltage frequency are not identical, which may include that the values of the reference value components of the direct axis voltage frequency in the plurality of reference values are completely different, or that the values of the reference value components of the direct axis voltage frequency in the plurality of reference values are different.

For example, the first sequence of voltage reference values may be represented as { (U) _d ,f ₁ ,t ₁₁ )，{(U _d ,f ₂ ,t ₁₂ ,)，……，{(U _d ,f _n1 ,t _1n (v), n=1, 2,3 … …, n1=1, 2,3 … …; wherein U is _d A reference value component representing the amplitude of the direct axis voltage, f _n1 Reference value component, t, representing the frequency of the direct voltage _1n A reference value component representing the duration of the direct axis voltage frequency.

Correspondingly, in the first voltage reference value sequence corresponding to the target square wave voltage, a reference value component U representing the amplitude of the direct-axis voltage _d May be identical and represent a reference value component f of the direct voltage frequency ₁ ～f _n1 The reference value components of at least two of the direct axis voltage frequencies are different.

As described above, in some implementations, the frequency variation of the target square wave voltage may be a periodic variation, and thus, the duration corresponding to the reference value component of the direct axis voltage frequency may be set to be a period length, for example, the reference value component f of the direct axis voltage frequency ₁ Corresponding duration t ₁₁ I.e. the period length. Of course, in the embodiment of the present application, the duration corresponding to the reference value component of the direct-axis voltage frequency may also be smaller than the period length, for example, the reference value component f of the direct-axis voltage frequency ₁ Corresponding duration t ₁₁ Is half a period in length. Also for example, the reference value component f of the direct axis voltage frequency ₁ Corresponding duration t ₁₁ One third of the length of a cycle, which is not limiting in this example.

In general, the higher the magnitude of the target square wave voltage, the higher the efficiency of heating the power battery, and thus, the magnitude of the target square wave voltage may be determined based on the voltage of the power battery, for example, the reference value component of the magnitude of the direct axis voltage may be equal to the voltage of the power battery. Of course, in the embodiment of the present application, the reference value component of the direct-axis voltage amplitude may be smaller than the voltage of the power battery, and the determination manner of the reference value component of the direct-axis voltage amplitude will be described with reference to formula 1, which is not described herein for brevity.

Having described the current operating parameters and the first voltage reference value sequence of the motor in the embodiments of the present application, generating the first control signal based on the current operating parameters and the first voltage reference value sequence is described below in connection with fig. 4.

Referring to fig. 4, in some implementations, if the current operating parameter of the motor includes the current of the motor stator, the current of the current motor stator (in "Id _fdk "representation" and current reference value (in "Id) _rms "representative of") is input to the PI regulator 410, and accordingly, the PI regulator 410 outputs an adjustment value for the frequency of the target square wave voltage to the modulator 420, and the modulator 420 modulates based on the adjustment value and a reference value component of the direct-axis voltage amplitude in the first voltage reference value sequence, to obtain a first control signal, so as to control the power module to output the target square wave voltage to the motor. For ease of understanding, the generation manner of the first control signal in the embodiment of the present application will be described with reference to fig. 5, which is not repeated herein for brevity.

It should be noted that the current reference value may be a preset current value. In some implementations, the current reference may be determined based on a heating efficiency of the power cell. In general, the higher the current reference value, the higher the heating efficiency of the power cell. The lower the current reference value, the lower the heating efficiency of the power cell. Of course, in the embodiment of the present application, the current reference value may also be a current reference value set by an experimenter based on experience, which is not limited in the embodiment of the present application.

In the embodiment of the application, the first control signal can be generated based on the current operation parameters of the motor so as to adjust the target square wave voltage of the direct axis of the input motor, namely, the voltage of the input motor is adjusted through closed loop control, and the control precision of the voltage of the input motor is improved.

Example 2 is described taking a square wave voltage with a target square wave voltage as a frequency change and a magnitude change as an example.

In some implementations, the control module is configured to: receiving current operation parameters of a motor; and generating a first control signal according to the current operation parameter and a second voltage reference value sequence of the straight shaft.

In some implementations, the second sequence of voltage reference values includes a plurality of reference values, each reference value of the plurality of reference values including the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency.

Because the target square wave voltage is a square wave voltage with frequency variation and amplitude variation, the reference value components of the amplitude of the direct-axis voltage in the multiple reference values are not identical, and the reference value components of the direct-axis voltage frequency in the multiple reference values are not identical.

The non-identical values of the reference value components of the direct axis voltage frequency may include that the values of the reference value components of the direct axis voltage frequency in the plurality of reference values are completely different, or that the values of the reference value components of the direct axis voltage frequency in the plurality of reference values are different.

The non-identical values of the reference value components of the direct axis voltage amplitude may include that the values of the reference value components of the direct axis voltage amplitude in the plurality of reference values are completely different, or that the values of the reference value components of the direct axis voltage amplitude in the plurality of reference values are different.

For example, the second sequence of voltage reference values may be represented as { (U) _d1 ,f ₁ ,t ₂₁ )，{(U _d2 ,f ₂ ,t ₂₂ ,)，……，{(U _dn ,f _n2 ,t _2n (v), n=1, 2,3 … …, n2=1, 2,3 … …; wherein U is _dn A reference value component representing the amplitude of the direct axis voltage, f _n2 Reference value component, t, representing the frequency of the direct voltage _2n A reference value component representing the duration of the direct axis voltage frequency.

Correspondingly, in the second voltage reference value sequence corresponding to the target square wave voltage, a reference value component U representing the amplitude of the direct-axis voltage _d1 ～U _dn The reference value components of at least two of the direct axis voltage amplitudes are different and the reference value component f representing the direct axis voltage frequency ₁ ～f _n2 The reference value components of at least two of the direct axis voltage frequencies are different.

As described above, in some implementations, the frequency variation of the target square wave voltage may be a periodic variation, and thus, the duration corresponding to the reference value component of the direct axis voltage frequency may be set to be a period length, for example, the reference value component f of the direct axis voltage frequency ₁ Corresponding duration t ₂₁ I.e. the period length. Of course, in the embodiment of the present application, the duration corresponding to the reference value component of the direct-axis voltage frequency may also be smaller than the period length, for example, the reference value component f of the direct-axis voltage frequency ₁ Corresponding duration t ₂₁ Is half a period in length. Also for example, the reference value component f of the direct axis voltage frequency ₁ Corresponding duration t ₂₁ One third of the length of a cycle, which is not limiting in this example.

In general, the higher the magnitude of the target square wave voltage, the higher the efficiency of heating the power battery, and thus, the maximum value of the magnitude of the target square wave voltage may be determined based on the voltage of the power battery, for example, the maximum value of the reference value component of the magnitude of the direct axis voltage may be equal to the voltage of the power battery. Of course, in the embodiment of the present application, the maximum value of the reference value component of the direct-axis voltage amplitude may be smaller than the voltage of the power battery, and the determination manner of the reference value component of the direct-axis voltage amplitude will be described with reference to formula 2, which is not described herein for brevity.

In some implementations, the second sequence of voltage reference values may be determined based on a heating parameter of the power cell and/or a maximum noise threshold of the motor. That is, the control module is further configured to: acquiring heating parameters of a power battery and/or a maximum noise threshold of a motor; a second sequence of voltage reference values is determined based on the heating parameter and/or the maximum noise threshold.

In some implementations, the heating parameters of the power cell may include a heating time, a heating efficiency, and the like of the power cell. Accordingly, the heating parameter may be used to determine a reference value component of the direct axis voltage amplitude in the second voltage reference value sequence. Taking heating parameters as heating efficiency of the power battery as an example, the higher the heating efficiency is, the larger the reference value component of the direct-axis voltage amplitude in the second voltage reference value sequence is, and conversely, the lower the heating efficiency is, the smaller the reference value component of the direct-axis voltage amplitude in the second voltage reference value sequence is.

Generally, if the frequency in the second voltage reference value sequence is higher, or the reference value component of the duration of the direct axis voltage frequency in the second voltage reference value sequence is smaller, the frequency of the target square wave voltage changes faster, which helps to reduce the noise of the motor. Thus, in embodiments of the present application, the reference value component of the direct axis voltage frequency and/or the reference value component of the duration of the direct axis voltage frequency in the second voltage reference value sequence may be determined based on a maximum noise threshold of the motor. For example, when the maximum noise threshold of the motor is low, the higher the value of the reference value component of the direct-axis voltage frequency in the second voltage reference value sequence, the smaller the value of the reference value component of the duration of the direct-axis voltage frequency. For another example, when the maximum noise threshold of the motor is high, the lower the value of the reference value component of the direct axis voltage frequency in the second voltage reference value sequence is, the greater the value of the reference value component of the duration of the direct axis voltage frequency is.

Having described the current operating parameters of the motor and the second sequence of voltage references in embodiments of the present application, the generation of the first control signal based on the current operating parameters and the first sequence of voltage references is described further below in connection with fig. 4.

Referring to fig. 4, in some implementations, if the current operating parameter of the motor includes the current of the motor stator, the current of the current motor stator (in "Id _fdk "representation" and current reference value (in "Id) _rms "representative of) the target square wave voltage is input to the PI regulator 410, and accordingly, the PI regulator 410 outputs an adjustment value for the frequency of the target square wave voltage to the modulator 420, and the modulator 420 modulates based on the adjustment value and a reference value component of the direct-axis voltage amplitude in the second voltage reference value sequence, so as to obtain a first control signal, so as to control the power module to output the target square wave voltage to the motor. For ease of understanding, the generation manner of the first control signal in the embodiment of the present application will be described with reference to fig. 6, which is not repeated herein for brevity.

In some scenarios, the motor may drive the vehicle through a gear pair. However, in the actual design or installation process, due to the reasons of design and manufacturing errors, limited assembly precision and the like of the gear pair, a certain gap always exists between the two gears, so that the driving wheel in the gear pair may collide with the driven wheel, and larger impact or noise is generated.

Therefore, in order to avoid the above-mentioned problem, in the embodiment of the present application, a target current may be input on the quadrature axis of the motor to control the motor to generate a tooth-leaning moment so that one side between the driven wheel and the driving wheel is leaned together. That is, the control module is further configured to: and sending a second control signal to the power module, wherein the second control signal is used for controlling the power module to input a target current to the quadrature axis of the motor, and the target current is used for controlling the motor to generate the tooth leaning moment. Of course, in the embodiment of the present application, if the above problem is not considered, the current on the intersecting axes of the motor may be 0.

In the embodiment of the application, the target current may be provided by a power battery. As introduced above, the target square wave voltage may also be provided by the voltage of the power cell, that is, the power cell needs to provide the target current and the target square wave voltage at the same time. In some implementations, if the magnitude of the target square wave voltage is constant, the magnitude U of the target square wave voltage may be determined based on equation 1 _d ，

Wherein U is _dc Represents the voltage of the power battery, R _s Indicating the internal resistance of the motor, I _q Representing the motor's quadrature current (i.e., target current).

In the embodiment of the present application, the amplitude U of the target square wave voltage is calculated by equation 1 _d A portion of the voltage of the power cell may be distributed to generate the quadrature current and the remaining portion may be used entirely to generate the target square wave voltage, which may help to reduce the time to heat the power cell and increase the heating efficiency of the power cell.

On the other hand, the voltage of a part of power batteries is used for generating the quadrature current, so that tooth leaning moment is provided for the motor, and the phenomenon that the driving wheel and the driven wheel in the gear pair collide due to gaps in the actual design or installation process is avoided, and larger impact or noise is generated.

In other implementations, if the amplitude of the target square wave voltage varies, the maximum amplitude U of the target square wave voltage may be determined based on equation 2 _max ，

In the embodiment of the application, the maximum amplitude U of the target square wave voltage is calculated by the formula 2 _max A part of the voltage of the power battery can be distributed to generate the quadrature current, the rest part of the voltage is used for calculating the maximum amplitude of the target square wave voltage, and then the amplitude of the target square wave voltage can be adjusted based on the maximum amplitude of the target square wave voltage to form the target square wave voltage with amplitude variation and frequency variation, so that the time for heating the power battery can be reduced, and the heating efficiency of the power battery can be improved.

In an embodiment of the present application, whether the above-mentioned scheme for heating the power battery is started or not may be determined based on the temperature of the power battery. In some implementations, if the temperature of the power cell meets a preset condition, a scheme for heating the power cell may be initiated. In other implementations, if the temperature of the power cell does not meet the preset condition, the heating scheme for the power cell may be turned off. Of course, in the embodiment of the present application, whether the above-mentioned scheme for heating the power battery is started may be determined based on the ambient temperature, which is not limited in the embodiment of the present application.

In some implementations, the meeting the preset condition may include a temperature of the power battery being below a preset temperature threshold. Conversely, failing to meet the preset condition may include the temperature of the power cell being above a preset temperature threshold. Of course, in the embodiment of the present application, the implementation manner of the preset condition is not limited. For example, the satisfaction of the preset condition may include that the temperature of the power battery does not belong to the preset temperature interval, and conversely, the non-satisfaction of the preset condition may include that the temperature of the power battery belongs to the preset temperature interval.

In the embodiment of the application, the above-mentioned scheme of starting or stopping the heating of the power battery may be performed by a control module of the motor controller. For example, when the preset condition is met, the control module sends a first control signal to the power module. For another example, the control module does not send the first control signal when the preset condition is not satisfied. Of course, in the embodiment of the present application, the above-mentioned scheme of starting or stopping the heating of the power battery may also be performed by other processing modules having related functions, for example, a vehicle controller, etc., which is not limited in this embodiment of the present application.

In an embodiment of the present application, the temperature of the power battery may include a temperature of a battery cell in the power battery. Of course, in the embodiment of the present application, the temperature of the power battery may also include the temperature of the outer surface of the power battery, which is not limited in the embodiment of the present application.

In order to facilitate understanding, the following describes the solution of the embodiment of the present application by taking embodiment 1 and embodiment 2 as examples. It should be noted that, the process of generating the first control signal and the second control signal by using the closed-loop control method is mainly described in embodiment 1 and embodiment 2, and the terms related thereto may be referred to the above description, and are not repeated herein for brevity.

In example 1, it is assumed that the target square wave voltage is a square wave voltage whose frequency varies periodically and whose amplitude is constant. The first sequence of voltage reference values may be represented as { (U) _d ,f ₁ ,t ₁₁ )，{(U _d ,f ₂ ,t ₁₂ ,)，……，{(U _d ,f _n1 ,t _1n (v) wherein U _d Can be determined based on equation 1. The current reference value of the quadrature axis can be constant current i _q And (3) the method. See FIG. 5Is shown to be based on a target voltage reference value (U _d ,f _n1 ,t _1n For example, a scheme for generating a first control signal in embodiments of the present application is described, which may include processes 510-580.

It should be noted that, based on other voltage reference values in the first voltage reference value sequence, the scheme for adjusting the target square wave voltage is similar to the following description, and for brevity, the following description is omitted.

In process 510, control module 121 may obtain current operating parameters of motor 130.

In some implementations, the control module 121 may obtain the current i input by the power module 122 to the motor 130 _a And i _b To determine the stator current of the motor 130. For example, referring to fig. 5, the three-phase inverter bridge of the power module 122 is connected to the three-phase winding of the motor 130, and the control module 121 may obtain the current i from the output terminal of the three-phase inverter bridge _a And i _b 。

It should be noted that, since the direct axis and the quadrature axis of the motor 130 are virtual axes, accordingly, the current on the direct axis and the current on the quadrature axis cannot be directly collected, in the embodiment of the present application, the direct axis current i may be calculated by collecting the current output by the three-phase inverter bridge _d Sum of quadrature axis current i _q `。

In process 520, the current i is converted using a three-phase stationary coordinate system (denoted by "abc") and a two-phase stationary coordinate system (denoted by "αβ") _a And i _b Coordinate conversion is carried out to obtain current i _α And i _β 。

In some implementations, the current i may be deduced by a Clarke (Clarke) transformation _a And i _b And converting from the three-phase static coordinate system into the two-phase static coordinate system.

In process 530, the current i is converted using a two-phase stationary coordinate system (denoted by "αβ") and a two-phase rotating coordinate system (denoted by "qd") _α And i _β Coordinate conversion is carried out to obtain current i _q ' also known as quadrature current feedback value) and current i _d ' also known as straight shaftCurrent feedback value).

In some implementations, the current i may be deduced by Park (Park) transformation _α And i _β Converted from a two-phase stationary coordinate system into a two-phase rotating coordinate system.

Since the two-phase rotation coordinate system is related to the current operation parameter of the motor 130 (for example, the position of the motor 130 and the speed of the motor 130, etc.), the current operation parameter of the motor 130 needs to be determined when performing the coordinate conversion. For example, referring to fig. 5, the control module 121 may acquire the position of the motor 130 and the speed of the motor 130 based on position and speed sensors.

In process 540, based on the quadrature axis current reference i _q Quadrature axis current i _q The difference between' determines the adjustment value 1.

In some implementations, the control module 121 may determine the quadrature current reference value i _q Quadrature axis current i _q The difference between the motor 130 and the PI regulator, and accordingly, the PI regulator outputs an adjustment value 1, wherein the adjustment value 1 is used to adjust the target current input to the motor 130 to satisfy the quadrature current reference value i _q `。

It should be noted that, in the embodiment of the present application, the above-mentioned target current satisfying the quadrature current reference value may be understood as a current similar to the quadrature current reference value due to the existence of the control error. Of course, in the present embodiment, the target current may be equal to the quadrature current reference value if the control error is small enough.

In process 550, based on the current reference i _d Direct axis current i _d The difference between' determines the adjustment value 2.

In some implementations, the control module 121 may determine the current reference value i _d Direct axis current i _d The difference between the square wave voltages is input into the PI regulator, and accordingly, the PI regulator outputs an adjustment value 2, wherein the adjustment value 2 is used for adjusting the frequency of the target square wave voltage to meet the reference value component f of the direct-axis voltage frequency in the target voltage reference value _n1 In other words, the adjustment value 2 is used for adjustment purposesA reference value component t whose frequency satisfies the duration of the direct-axis voltage frequency in the target voltage reference value _1n 。

In some implementations, the adjustment value 2 may be based on the direct current i _d Effective value and current reference value i _d The difference between is determined, wherein, the straight axis current i _d Effective value of

Wherein T represents the direct current i _d Duration of'.

In some implementations, the direct axis current i _d Effective value and current reference value i _d The difference between them can be obtained, for example, by comparing the current reference value i _d With direct current i _d The effective value is obtained by difference.

In process 560, a reference value component U based on the direct axis voltage magnitude in the target voltage reference value _d And an adjustment value 3, modulating to obtain an adjustment value 4, where the adjustment value 4 is used to adjust the power module 122 to output a target square wave voltage meeting the target voltage reference value to the motor 130.

It should be noted that, in the embodiment of the present application, due to the existence of the control error, the above-mentioned target square wave voltage satisfying the target voltage reference value may be understood as a target square wave voltage similar to each reference value component in the target voltage reference value. Of course, in the present embodiment, if the control error is small enough, the parameters (e.g., amplitude, frequency, etc.) of the target square wave voltage may be the same as the reference value component indicated by the target voltage reference value.

In process 570, the two-phase rotating coordinate system and the two-phase stationary coordinate system are utilized to convert the coordinates of the adjustment value 4 and the adjustment value 2, and the converted adjustment value 4 and the converted adjustment value 2 are obtained.

In some implementations, adjustment value 4 and adjustment value 2 may be coordinate transformed by an inverse transform of the park transform.

In process 580, the converted adjustment value 4 and the converted adjustment value 2 are modulated to obtain a first control signal and a second control signal.

The first control signal is used to control the power module 122 to output a target square wave voltage satisfying the target voltage reference value to the direct axis of the motor 130. The second control information is used to control the power module 122 to output the target current satisfying the reference value of the quadrature current to the quadrature axis of the motor 130.

In embodiment 2, it is assumed that the target square wave voltage is a square wave voltage with a frequency periodically varying and an amplitude periodically varying, wherein the period of the frequency variation and the period of the amplitude variation are the same. The second sequence of voltage reference values may be represented as { (U) _d1 ,f ₁ ,t ₂₁ )，{(U _d2 ,f ₂ ,t ₂₂ ,)，……，{(U _dn ,f _n2 ,t _2n (v) wherein U _dn U as determined by equation 2 can be satisfied _dmax . The current reference value of the quadrature axis can be constant current i _q . As shown in fig. 6, to calculate a target voltage reference value (U _dn ,f _n2 ,t _2n For example, a scheme for generating the first control signal in embodiments of the present application is described, which may include processes 610-680.

It should be noted that, based on other voltage reference values in the second voltage reference value sequence, the scheme for adjusting the target square wave voltage is similar to the following description, and for brevity, the following description is omitted.

In process 610, control module 121 may obtain current operating parameters of motor 130.

In some implementations, the control module 121 may obtain the current i input by the power module 122 to the motor 130 _a And i _b To determine the stator current of the motor 130. For example, referring to fig. 6, the three-phase inverter bridge of the power module 122 is connected to the three-phase winding of the motor 130, and the control module 121 may obtain the current i from the output terminal of the three-phase inverter bridge _a And i _b 。

It should be noted that, since the direct axis and the quadrature axis of the motor 130 are virtual axes, accordingly, the current on the direct axis and the current on the quadrature axis cannot be directly collected, and in this embodiment of the present application, the current can be obtained byCollecting the current output by the three-phase inverter bridge to calculate the direct-axis current i _d Sum of quadrature axis current i _q `。

In process 620, the current i is converted using a three-phase stationary coordinate system (denoted by "ABC") and a two-phase stationary coordinate system (denoted by "αβ") _a And i _b Coordinate conversion is carried out to obtain current i _α And i _β 。

In some implementations, the current i may be deduced by Clarke transformation _a And i _b And converting from the three-phase static coordinate system into the two-phase static coordinate system.

In process 630, the current i is converted using a two-phase stationary coordinate system (denoted by "αβ") and a two-phase rotating coordinate system (denoted by "qd") _α And i _β Coordinate conversion is carried out to obtain the quadrature axis current i _q ' also known as quadrature axis current feedback value) and direct axis current i _d (also known as direct current feedback value).

In some implementations, the current i may be derived by park transformation _α And i _β Converted from a two-phase stationary coordinate system into a two-phase rotating coordinate system.

Since the two-phase rotation coordinate system is related to the current operation parameter of the motor 130 (for example, the position of the motor 130 and the speed of the motor 130, etc.), the current operation parameter of the motor 130 needs to be determined when performing the coordinate conversion. For example, referring to fig. 6, the control module 121 may obtain current operating parameters of the motor 130 based on position and speed sensors.

In process 640, a reference value i is based on the quadrature axis current _q Current i _q The difference between' determines the adjustment value 1.

In some implementations, the control module 121 may determine the quadrature current reference value i _q Current i _q The difference between the motor 130 and the PI regulator, and accordingly, the PI regulator outputs an adjustment value 1, wherein the adjustment value 1 is used to adjust the target current input to the motor 130 to satisfy the quadrature current reference value i _q 。

It should be noted that, in the embodiment of the present application, the above-mentioned target current satisfying the quadrature current reference value may be understood as a target current similar to the quadrature current reference value due to the existence of the control error. Of course, in the present embodiment, the target current may be equal to the quadrature current reference value if the control error is small enough.

In process 650, based on the current reference i _d Direct axis current i _d The difference between' determines the adjustment value 2.

In some implementations, the control module 121 may determine the current reference value i _d Direct axis current i _d The difference between the square wave voltages is input into the PI regulator, and accordingly, the PI regulator outputs an adjustment value 2, wherein the adjustment value 2 is used for adjusting the frequency of the target square wave voltage to meet the reference value component f of the direct-axis voltage frequency in the target voltage reference value _n2 In other words, the adjustment value 2 is used for adjusting the reference value component t of the duration of the frequency of the target square wave voltage to meet the direct axis voltage frequency in the target voltage reference value _2n 。

Wherein T represents the direct current i _d Duration of'.

In process 660, a reference value component U based on the direct axis voltage magnitude in the target voltage reference value _dn And an adjustment value 3, modulating to obtain an adjustment value 4, where the adjustment value 4 is used to adjust the power module 122 to output a target square wave voltage meeting the target voltage reference value to the motor 130.

In process 670, the two-phase rotating coordinate system and the two-phase stationary coordinate system are utilized to convert the coordinates of the adjustment value 4 and the adjustment value 2, and the converted adjustment value 4 and the converted adjustment value 2 are obtained.

In process 680, the converted adjustment value 4 and the converted adjustment value 2 are modulated to obtain a first control signal and a second control signal.

Fig. 7 shows current conversion efficiency when a power cell is heated using a target square wave voltage according to an embodiment of the present application. Wherein fig. 7 (a) shows the current of the power cell as a function of time. Fig. 7 (b) shows the change with time of the alternating current input to the motor a phase. Fig. 7 (c) shows the variation of the ac power on the ac bus in the power module with time. Fig. 7 (d) shows the change of the target square wave voltage with time.

Referring to fig. 7 (d), the target square wave voltage is a square wave voltage whose frequency varies periodically and whose amplitude is constant. After the target square wave voltage shown in fig. 7 (d) is input into the direct axis of the motor, it can be seen that the alternating current on the alternating current bus in fig. 7 (c) is similar to the current of the power battery in fig. 7 (a), that is, the current on the alternating current bus is basically input into the power battery to heat the power battery, which can indicate that the conversion rate of the current is higher by adopting the method of the embodiment of the application, and the problems that the ripple current is dissipated in the known scheme, the conversion rate of the current is not high, and the heating efficiency of the power battery is reduced can be avoided.

The transposed embodiments of the present application are described above in detail in conjunction with fig. 1-7, and the method embodiments of the present application are described below in detail in conjunction with fig. 8. It is to be understood that the description of the method embodiments corresponds to the description of the device embodiments, and that parts not described in detail can therefore be seen in the preceding device embodiments. Additionally, method embodiments may be performed by any of the apparatus described above.

Fig. 8 is a schematic flow chart of a heating method of the power battery of the embodiment of the present application. It should be appreciated that the method illustrated in FIG. 8 may be performed by a control module. The method shown in fig. 8 includes step S810 and step S820.

In step S810, a first control signal is sent to a power module of a motor controller.

The first control signal is used for controlling the power module to input a target square wave voltage to a direct-current shaft of the motor, the target square wave voltage is square wave voltage with amplitude changing and/or frequency changing, and the target square wave voltage is used for generating alternating pulse current on the direct-current bus.

In step S820, the power battery is heated using the pulse current.

In some possible implementations, the target square wave voltage is a square wave voltage of varying frequency and constant amplitude.

In some possible implementations, the method further includes: receiving current operation parameters of the motor; generating the first control signal according to the current operating parameter and a first voltage reference value sequence of the straight axis, wherein the first voltage reference value sequence comprises a plurality of reference values, and each reference value in the plurality of reference values comprises the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency; the values of the reference value components of the direct-axis voltage amplitude values in the plurality of reference values are equal, and the values of the reference value components of the direct-axis voltage frequency in the plurality of reference values are not identical.

In some possible implementationsIn this way, the target square wave voltage is a square wave voltage with constant amplitude, and the amplitude U of the target square wave voltage _d Satisfy the following requirements

In some possible implementations, the target square wave voltage is a square wave voltage with a frequency variation and a magnitude variation.

In some possible implementations, the method further includes: receiving current operation parameters of the motor; generating the first control signal according to the current operating parameter and a second voltage reference value sequence of the straight axis, wherein the second voltage reference value sequence comprises a plurality of reference values, and each reference value in the plurality of reference values comprises the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency; the reference value components of the direct-axis voltage amplitude values in the plurality of reference values are not identical, and the reference value components of the direct-axis voltage frequency in the plurality of reference values are not identical.

In some possible implementations, the method further includes: acquiring heating parameters of the power battery and/or a maximum noise threshold of the motor; and determining the second voltage reference value sequence according to the heating parameter and/or the maximum noise threshold value.

In some possible implementations, the heating parameter is used to determine a reference value component of the direct axis voltage amplitude in the second voltage reference value sequence; and/or the maximum noise threshold is used to determine a reference value component of the direct axis voltage frequency and/or a reference value component of the duration of the direct axis voltage frequency in the second sequence of voltage reference values.

In some possible implementations, the maximum amplitude U of the target square wave voltage _max Satisfy the following requirements

In some possible implementations, the frequency of the target square wave voltage varies randomly or periodically; and/or the amplitude of the target square wave voltage is randomly changed or periodically changed.

In some possible implementations, the method further includes: and sending a second control signal to the power module, wherein the second control signal is used for controlling the power module to input target current to a quadrature axis of the motor, and the target current is used for controlling the motor to generate tooth leaning moment.

Embodiments of the present application also provide a computer program product comprising a computer program/instruction which, when executed by a processor, performs any of the methods described above.

It should be understood that in the embodiments of the present application, "B corresponding to a" means that B is associated with a, from which B may be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information.

It should be understood that the term "and/or" is merely an association relationship describing the associated object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It should be understood that, in various embodiments of the present application, the sequence numbers of the foregoing processes do not mean the order of execution, and the order of execution of the processes should be determined by the functions and internal logic thereof, and should not constitute any limitation on the implementation process of the embodiments of the present application.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be read by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a digital versatile disk (digital video disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A motor controller, comprising:

the power module is provided with a direct current bus and an alternating current bus, the direct current bus is used for receiving direct current output by the power battery, the power module is used for converting the direct current into alternating current, and the alternating current bus is used for outputting the alternating current to the motor;

the control module is connected with the power module and is used for sending a first control signal to the power module, the first control signal is used for controlling the power module to input a target square wave voltage to a direct shaft of the motor, the target square wave voltage is a square wave voltage with frequency change and/or amplitude change, the target square wave voltage is used for generating alternating pulse current on the direct current bus, and the pulse current is used for heating the power battery.

2. The motor controller of claim 1 wherein the target square wave voltage is a square wave voltage of varying frequency and constant amplitude.

3. The motor controller of claim 2, wherein the control module is configured to:

receiving current operation parameters of the motor;

generating the first control signal according to the current operating parameter and a first voltage reference value sequence of the straight axis, wherein the first voltage reference value sequence comprises a plurality of reference values, and each reference value in the plurality of reference values comprises the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency;

the values of the reference value components of the direct-axis voltage amplitude values in the plurality of reference values are equal, and the values of the reference value components of the direct-axis voltage frequency in the plurality of reference values are not identical.

4. The motor controller of claim 1 wherein the target square wave voltage is a frequency varying, amplitude varying square wave voltage.

5. The motor controller of claim 4, wherein the control module is configured to:

Receiving current operation parameters of the motor;

generating the first control signal according to the current operating parameter and a second voltage reference value sequence of the straight axis, wherein the second voltage reference value sequence comprises a plurality of reference values, and each reference value in the plurality of reference values comprises the following reference value components: a reference value component of the amplitude of the direct axis voltage, a reference value component of the direct axis voltage frequency, and a reference value component of the duration of the direct axis voltage frequency;

the reference value components of the direct-axis voltage amplitude values in the plurality of reference values are not identical, and the reference value components of the direct-axis voltage frequency in the plurality of reference values are not identical.

6. The motor controller of claim 5, wherein the control module is further configured to:

acquiring heating parameters of the power battery and/or a maximum noise threshold of the motor;

and determining the second voltage reference value sequence according to the heating parameter and/or the maximum noise threshold value.

7. The motor controller of claim 6 wherein the heating parameter is used to determine a reference value component of the direct axis voltage magnitude in the second voltage reference value sequence; and/or

The maximum noise threshold is used to determine a reference value component of the direct axis voltage frequency and/or a reference value component of a duration of the direct axis voltage frequency in the second sequence of voltage reference values.

8. The motor controller according to any one of claims 1 to 7, wherein the frequency of the target square wave voltage varies randomly or periodically; and/or the amplitude of the target square wave voltage is randomly changed or periodically changed.

9. The motor controller of any one of claims 1-8, wherein the control module is further configured to:

and sending a second control signal to the power module, wherein the second control signal is used for controlling the power module to input target current to a quadrature axis of the motor, and the target current is used for controlling the motor to generate tooth leaning moment.

10. A power system, comprising: a power battery, a motor and a motor controller according to any one of claims 1-9, both of which are connected to a power module in the motor controller.

11. A vehicle comprising the power system of claim 10.

12. A method of heating a power cell, comprising:

a first control signal is sent to a power module of a motor controller, the first control signal is used for controlling the power module to input a target square wave voltage to a direct axis of a motor, the target square wave voltage is a square wave voltage with amplitude changing and/or frequency changing, and the target square wave voltage is used for generating alternating pulse current on the direct current bus;

and heating the power battery by using the pulse current.

13. A computer program product comprising computer programs/instructions which, when executed by the computer program/instruction processor, implement the method of claim 12.