阅读说明：本技术 永磁同步电机的牵引特性确定方法、装置、设备及介质 (Method, device, equipment and medium for determining traction characteristics of permanent magnet synchronous motor ) 是由 杨北辉 朱龙胜 吴能峰 王辉华 于 2021-06-30 设计创作，主要内容包括：本申请公开了一种永磁同步电机的牵引特性确定方法、装置、设备及介质,该方法包括：根据永磁同步电机的属性特征确定永磁同步电机的目标运行参数,并基于电压极限椭圆确定与永磁同步电机相对应牵引特性图中的待估参数；其中,电压极限椭圆为含有永磁同步电机定子电阻的模型方程；利用目标运行参数和待估参数确定牵引特性图。因为是利用含有永磁同步电机定子电阻的电压极限椭圆来确定永磁同步电机牵引特性图中的待估参数,没有将永磁同步电机定子电阻上的电压忽略掉,所以,这样就可以减少待估参数与实际值之间的误差。这样就会使得创建所得的永磁同步电机的牵引特性图更加准确与可靠,由此就可以使得计算所得永磁同步电机的铜损耗更加精确。(The application discloses a method, a device, equipment and a medium for determining traction characteristics of a permanent magnet synchronous motor, wherein the method comprises the following steps: determining target operation parameters of the permanent magnet synchronous motor according to the attribute characteristics of the permanent magnet synchronous motor, and determining parameters to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on a voltage limit ellipse; the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance; and determining a traction characteristic map by using the target operation parameters and the parameters to be estimated. Because the voltage limit ellipse containing the stator resistor of the permanent magnet synchronous motor is used for determining the parameter to be estimated in the traction characteristic diagram of the permanent magnet synchronous motor, the voltage on the stator resistor of the permanent magnet synchronous motor is not ignored, and therefore, the error between the parameter to be estimated and the actual value can be reduced. Therefore, the created traction characteristic diagram of the permanent magnet synchronous motor is more accurate and reliable, and the calculated copper loss of the permanent magnet synchronous motor is more accurate.)

1. A method for determining a traction characteristic of a permanent magnet synchronous motor is characterized by comprising the following steps:

determining target operation parameters of the permanent magnet synchronous motor according to the attribute characteristics of the permanent magnet synchronous motor, and determining parameters to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on a voltage limit ellipse; the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance;

and determining the traction characteristic map by using the target operation parameters and the parameters to be estimated.

2. The traction characteristic determination method according to claim 1, wherein the process of determining the parameter to be estimated in the traction characteristic map corresponding to the permanent magnet synchronous motor based on the voltage limit ellipse comprises:

determining a first angular speed of a stator of a permanent magnet synchronous motor under starting torque according to the voltage limit ellipse, and determining a first dq-axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is less than or equal to the first angular speed; the starting torque is a parameter which is preset according to the attribute characteristics of the permanent magnet synchronous motor;

when the running state of the permanent magnet synchronous motor reaches the extreme value condition of the voltage limit ellipse, determining a second angular speed of the stator according to a current limit circle and the voltage limit ellipse so as to enable the permanent magnet synchronous motor to maintain the starting torque to run, and determining a second dq-axis current and a second stator current amplitude when the angular speed of the stator of the permanent magnet synchronous motor is greater than the first angular speed and less than or equal to the second angular speed;

determining the maximum angular speed of the stator according to the voltage limit ellipse, and determining a third dq-axis current, a third stator current amplitude and a target output torque of the permanent magnet synchronous motor when the angular speed of the stator is greater than the second angular speed and less than or equal to the maximum angular speed;

correspondingly, the process of determining the traction characteristic map by using the target operation parameter and the parameter to be estimated includes:

determining the traction characteristic map using the first angular velocity, the first dq-axis current, the first stator current magnitude, the second angular velocity, the second dq-axis current, the second stator current magnitude, the maximum angular velocity, the third dq-axis current, the third stator current magnitude, the starting torque, and the target output torque.

3. The traction characteristic determination method according to claim 2, wherein the process of determining a first angular velocity of a stator of a permanent magnet synchronous motor at a starting torque from the voltage limit ellipse, and determining a first dq-axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular velocity of the stator is less than or equal to the first angular velocity, includes:

determining the first angular speed of the stator of the permanent magnet synchronous motor under the starting torque according to a maximum torque current ratio control formula and the voltage limit ellipse, and determining the first dq-axis current and the first stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is less than or equal to the first angular speed by using the starting torque and the maximum torque current ratio control formula.

4. The traction characteristic determination method of claim 2 wherein the process of determining a second dq-axis current and a second stator current magnitude for the permanent magnet synchronous machine comprises:

and determining the second dq-axis current and the second stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is greater than the first angular speed and less than or equal to the second angular speed by using the voltage limit ellipse and a constant torque curve of the permanent magnet synchronous motor.

5. The traction characteristic determination method according to claim 2, wherein the process of determining the third dq-axis current, the third stator current amplitude, and the target output torque of the permanent magnet synchronous motor when the angular velocity of the stator is greater than the second angular velocity and less than or equal to the maximum angular velocity includes:

and determining the third dq-axis current, the third stator current amplitude and the target output torque of the permanent magnet synchronous motor when the angular speed of the stator of the permanent magnet synchronous motor is greater than the second angular speed and less than or equal to the maximum angular speed by using the voltage limit ellipse, the current limit circle and a torque equation of the permanent magnet synchronous motor.

6. A traction characteristic determination device of a permanent magnet synchronous motor, characterized by comprising:

the parameter calculation module is used for determining target operation parameters of the permanent magnet synchronous motor according to the attribute characteristics of the permanent magnet synchronous motor and determining parameters to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on a voltage limit ellipse; the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance;

and the characteristic map determining module is used for determining the traction characteristic map by utilizing the target operation parameters and the parameters to be estimated.

7. A traction characteristic determination apparatus of a permanent magnet synchronous motor, characterized by comprising:

a memory for storing a computer program;

a processor for implementing the steps of a method of determining traction characteristics of a permanent magnet synchronous machine according to any of claims 1 to 5 when executing said computer program.

8. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a computer program which, when being executed by a processor, carries out the steps of a method of determining traction characteristics of a permanent magnet synchronous machine according to any one of claims 1 to 5.

Technical Field

The invention relates to the technical field of permanent magnet synchronous motors, in particular to a method, a device, equipment and a medium for determining traction characteristics of a permanent magnet synchronous motor.

Background

When determining a traction characteristic diagram of a Permanent Magnet Synchronous Motor (PMSM), the existing literature data cannot accurately estimate related parameters of the PMSM, which may cause a large error in the calculated copper loss of the PMSM. At present, no effective solution exists for the technical problem.

Disclosure of Invention

In view of this, the present invention provides a method, an apparatus, a device and a medium for determining a traction characteristic of a permanent magnet synchronous motor, so as to obtain a more accurate calculated copper loss of the permanent magnet synchronous motor.

The specific scheme is as follows:

a traction characteristic determination method of a permanent magnet synchronous motor includes:

determining target operation parameters of the permanent magnet synchronous motor according to the attribute characteristics of the permanent magnet synchronous motor, and determining parameters to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on a voltage limit ellipse; the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance;

and determining the traction characteristic map by using the target operation parameters and the parameters to be estimated.

Preferably, the process of determining the parameter to be estimated in the traction characteristic diagram corresponding to the permanent magnet synchronous motor based on the voltage limit ellipse includes:

determining a first angular speed of a stator of a permanent magnet synchronous motor under starting torque according to the voltage limit ellipse, and determining a first dq-axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is less than or equal to the first angular speed; the starting torque is a parameter which is preset according to the attribute characteristics of the permanent magnet synchronous motor;

when the running state of the permanent magnet synchronous motor reaches the extreme value condition of the voltage limit ellipse, determining a second angular speed of the stator according to a current limit circle and the voltage limit ellipse so as to enable the permanent magnet synchronous motor to maintain the starting torque to run, and determining a second dq-axis current and a second stator current amplitude when the angular speed of the stator of the permanent magnet synchronous motor is greater than the first angular speed and less than or equal to the second angular speed;

determining the maximum angular speed of the stator according to the voltage limit ellipse, and determining a third dq-axis current, a third stator current amplitude and a target output torque of the permanent magnet synchronous motor when the angular speed of the stator is greater than the second angular speed and less than or equal to the maximum angular speed;

correspondingly, the process of determining the traction characteristic map by using the target operation parameter and the parameter to be estimated includes:

determining the traction characteristic map using the first angular velocity, the first dq-axis current, the first stator current magnitude, the second angular velocity, the second dq-axis current, the second stator current magnitude, the maximum angular velocity, the third dq-axis current, the third stator current magnitude, the starting torque, and the target output torque.

Preferably, the determining a first angular velocity of a stator of a permanent magnet synchronous motor under a starting torque according to the voltage limit ellipse, and determining a first dq-axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular velocity of the stator is less than or equal to the first angular velocity includes:

determining the first angular speed of the stator of the permanent magnet synchronous motor under the starting torque according to a maximum torque current ratio control formula and the voltage limit ellipse, and determining the first dq-axis current and the first stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is less than or equal to the first angular speed by using the starting torque and the maximum torque current ratio control formula.

Preferably, the process of determining the second dq-axis current and the second stator current amplitude of the permanent magnet synchronous motor includes:

and determining the second dq-axis current and the second stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is greater than the first angular speed and less than or equal to the second angular speed by using the voltage limit ellipse and a constant torque curve of the permanent magnet synchronous motor.

Preferably, the determining a third dq-axis current, a third stator current amplitude and a target output torque of the permanent magnet synchronous motor when the angular velocity of the stator is greater than the second angular velocity and less than or equal to the maximum angular velocity includes:

and determining the third dq-axis current, the third stator current amplitude and the target output torque of the permanent magnet synchronous motor when the angular speed of the stator of the permanent magnet synchronous motor is greater than the second angular speed and less than or equal to the maximum angular speed by using the voltage limit ellipse, the current limit circle and a torque equation of the permanent magnet synchronous motor.

Correspondingly, the invention also discloses a traction characteristic determination device of the permanent magnet synchronous motor, which comprises the following steps:

the parameter calculation module is used for determining target operation parameters of the permanent magnet synchronous motor according to the attribute characteristics of the permanent magnet synchronous motor and determining parameters to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on a voltage limit ellipse; the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance;

and the characteristic map determining module is used for determining the traction characteristic map by utilizing the target operation parameters and the parameters to be estimated.

Correspondingly, the invention also discloses equipment for determining the traction characteristic of the permanent magnet synchronous motor, which comprises:

a memory for storing a computer program;

a processor for implementing the steps of a method for determining a traction characteristic of a permanent magnet synchronous motor as disclosed in the foregoing when executing said computer program.

Accordingly, the present invention also discloses a computer readable storage medium having stored thereon a computer program which, when being executed by a processor, carries out the steps of a method for determining traction characteristics of a permanent magnet synchronous machine as disclosed in the foregoing.

Therefore, in the invention, because the voltage limit ellipse containing the stator resistor of the permanent magnet synchronous motor is used for determining the parameter to be estimated in the traction characteristic diagram corresponding to the permanent magnet synchronous motor, the voltage on the stator resistor of the permanent magnet synchronous motor is not ignored, and thus, the error between the parameter to be estimated and the actual value can be reduced. In this case, the traction characteristic diagram of the permanent magnet synchronous motor is created by using the parameter to be estimated and the target operation parameter determined according to the attribute characteristics of the permanent magnet synchronous motor, so that the created traction characteristic diagram of the permanent magnet synchronous motor is more accurate and reliable, and the calculated copper loss of the permanent magnet synchronous motor can be more accurate. Correspondingly, the traction characteristic determination device, equipment and medium of the permanent magnet synchronous motor provided by the invention also have the beneficial effects.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a flowchart of a method for determining a traction characteristic of a permanent magnet synchronous motor according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a traction characteristic diagram of a permanent magnet synchronous motor according to an embodiment of the present invention;

fig. 3 is a structural diagram of a traction characteristic determination apparatus of a permanent magnet synchronous motor according to an embodiment of the present invention;

fig. 4 is a structural diagram of a traction characteristic determining apparatus of a permanent magnet synchronous motor according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a flowchart of a method for determining a traction characteristic of a permanent magnet synchronous motor according to an embodiment of the present invention, where the method includes:

step S11: determining target operation parameters of the permanent magnet synchronous motor according to the attribute characteristics of the permanent magnet synchronous motor, and determining parameters to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on a voltage limit ellipse;

the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance;

step S12: and determining a traction characteristic map by using the target operation parameters and the parameters to be estimated.

In this embodiment, a method for determining a traction characteristic of a permanent magnet synchronous motor is provided, by which a traction characteristic map of the permanent magnet synchronous motor can be accurately determined. Specifically, in the method, firstly, the target operation parameters of the permanent magnet synchronous motor are determined according to the attribute characteristics of the permanent magnet synchronous motor, and it can be understood that, because some basic data of the permanent magnet synchronous motor are required to be used as support when the traction characteristic diagram of the permanent magnet synchronous motor is created, the purpose of the step is to determine the basic data when the traction characteristic diagram of the permanent magnet synchronous motor is created. The target operation parameters of the permanent magnet synchronous motor comprise the starting torque of the permanent magnet synchronous motor and the maximum current amplitude allowed to flow by the permanent magnet synchronous motor; and then, determining parameters to be estimated in the traction characteristic diagram of the permanent magnet synchronous motor by using a voltage limit ellipse containing the stator resistor of the permanent magnet synchronous motor. The parameters to be estimated in the traction characteristic diagram comprise the current on the dq axis of the permanent magnet synchronous motor in the operation process, the stator current amplitude and the output torque of the permanent magnet synchronous motor.

It is conceivable that, because the voltage limit ellipse contains the stator resistance of the permanent magnet synchronous motor, the parameter to be estimated in the traction characteristic diagram of the permanent magnet synchronous motor can be calculated more accurately by using the voltage limit ellipse compared with the prior art. In this case, the traction characteristic diagram of the permanent magnet synchronous motor is created by using the parameter to be estimated and the target operation parameter determined according to the attribute characteristics of the permanent magnet synchronous motor, so that the created traction characteristic diagram is more accurate, and the copper loss of the permanent magnet synchronous motor can be more accurately calculated through the traction characteristic diagram of the permanent magnet synchronous motor.

It can be seen that, in the embodiment, because the parameter to be estimated in the traction characteristic diagram corresponding to the permanent magnet synchronous motor is determined by using the voltage limit ellipse containing the stator resistance of the permanent magnet synchronous motor, the voltage on the stator resistance of the permanent magnet synchronous motor is not ignored, so that the error between the parameter to be estimated and the actual value can be reduced. In this case, the traction characteristic diagram of the permanent magnet synchronous motor is created by using the parameter to be estimated and the target operation parameter determined according to the attribute characteristics of the permanent magnet synchronous motor, so that the created traction characteristic diagram of the permanent magnet synchronous motor is more accurate and reliable, and the calculated copper loss of the permanent magnet synchronous motor can be more accurate.

Based on the above embodiments, this embodiment further describes and optimizes the technical solution, and as a preferred implementation, the above steps: the process of determining the parameter to be estimated in the traction characteristic diagram corresponding to the permanent magnet synchronous motor based on the voltage limit ellipse comprises the following steps:

determining a first angular speed of a stator of the permanent magnet synchronous motor under the starting torque according to the voltage limit ellipse, and determining a first dq-axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is less than or equal to the first angular speed; the starting torque is a parameter which is preset according to the attribute characteristics of the permanent magnet synchronous motor;

when the running state of the permanent magnet synchronous motor reaches the extreme value condition of the voltage limit ellipse, determining a second angular speed of the stator according to the current limit circle and the voltage limit ellipse so as to enable the permanent magnet synchronous motor to maintain the starting torque to run, and determining a second dq-axis current and a second stator current amplitude when the angular speed of the stator of the permanent magnet synchronous motor is greater than the first angular speed and less than or equal to the second angular speed;

determining the maximum angular velocity of the stator according to the voltage limit ellipse, and determining a third dq-axis current, a third stator current amplitude and a target output torque of the permanent magnet synchronous motor when the angular velocity of the stator is greater than the second angular velocity and less than or equal to the maximum angular velocity;

correspondingly, the process for determining the traction characteristic map by using the target operation parameters and the parameters to be estimated comprises the following steps:

determining a traction characteristic map using the first angular velocity, the first dq-axis current, the first stator current magnitude, the second angular velocity, the second dq-axis current, the second stator current magnitude, the maximum angular velocity, the third dq-axis current, the third stator current magnitude, the starting torque, and the target output torque.

In this embodiment, the operation process of the permanent magnet synchronous motor can be divided into three stages according to the angular velocity of the stator of the permanent magnet synchronous motor, where the first stage is a constant torque 1 region of the permanent magnet synchronous motor, the second stage is a constant torque 2 region of the permanent magnet synchronous motor, and the third stage is a constant power region of the permanent magnet synchronous motor.

Specifically, when calculating the starting current of the permanent magnet synchronous motor, it can be assumed that the starting torque of the permanent magnet synchronous motor is T_{e_st}The permanent magnet synchronous motor meets the maximum torque current ratio optimization target when being started, and the maximum torque current ratio optimization target is determined according to the permanent magnet synchronous motorThe starting current i corresponding to the permanent magnet synchronous motor under the starting torque can be solved by the constant torque curve and the maximum torque current ratio_d1And i_q1And the stator current amplitude I corresponding thereto_max1. Namely:

in the formula, T_{e_st}For starting torque, N_pIs a logarithm of poles,. psi_fIs a permanent magnet flux linkage, L_dIs a direct axis inductor, L_qIs a quadrature axis inductor, i_dIs d-axis current, i_qFor q-axis current, permanent magnet flux linkage psi_fCan be according to E_f＝ψ_fOmega is calculated to obtain_fIs back electromotive force of the permanent magnet synchronous motor, and omega is the permanent magnet synchronous motor at E_fThe corresponding synchronous angular velocity.

When the permanent magnet synchronous motor is in a constant torque 1 region, the output torque of the permanent magnet synchronous motor is starting torque T_{e_st}The angular speed of the stator of the permanent magnet synchronous motor is low, the dq axis voltage of the permanent magnet synchronous motor always meets the limiting condition of voltage limit ellipse, and at the moment, the current vector of the stator of the permanent magnet synchronous motor is controlled to have a radius I_max1The first dq axis current i of the permanent magnet synchronous motor under the state can be obtained_d1And i_q1When the first qd axis current i is obtained_d1And i_q1Then, the first stator current amplitude of the permanent magnet synchronous motor in the state can be calculated. Then, the first angular velocity ω of the permanent magnet synchronous motor stator in the constant torque 1 region can be solved by using the limiting condition of the voltage limit ellipse_b。

Along with the gradual increase of the stator angular speed of the permanent magnet synchronous motor, the back electromotive force of the permanent magnet synchronous motor on a dq axis is larger and larger, and when the running state of the permanent magnet synchronous motor reaches the limit condition of a voltage limit circle, the permanent magnet synchronous motor enters a constant torque 2 area. In this case, the amplitude of the stator current of the permanent magnet synchronous motor does not reach the limit, and the amplitude of the stator current can be increased to ensure that the stator current is not limited to the limitThe permanent magnet synchronous motor can maintain to output constant starting torque. The stator voltage amplitude of the permanent magnet synchronous motor in the constant torque 2 area is constant V_maxThe output power of the permanent magnet synchronous motor in the region can increase along with the increase of the amplitude of the stator current, and in fact, the constant torque 2 region can also be called a constant voltage power rising region.

Specifically, when the operating state of the permanent magnet synchronous motor reaches the limit condition of the voltage limit circle, the second angular velocity of the permanent magnet synchronous motor can be determined by solving the simultaneous equations of the constant torque curve, the voltage limit ellipse and the current limit circle. Namely:

in the formula, T_{e_st}For starting torque, N_pIs a logarithm of poles,. psi_fIs a permanent magnet flux linkage, L_dIs a direct axis inductor, L_qIs a quadrature axis inductor, i_d2When the angular speed of the stator is a second angular speed, the permanent magnet synchronous motor flows on a d axis i_q2When the angular velocity of the stator is a second angular velocity, the permanent magnet synchronous motor flows on a q axis, I_maxThe radius of the current limit circle.

When the current i of the permanent magnet synchronous motor on the dq axis is obtained through calculation_d2And i_q2Substituting the voltage into the voltage limit ellipse to obtain a second angular velocity omega of the stator of the permanent magnet synchronous motor_t. Wherein, the expression of the voltage limit ellipse is:

in the formula, R_sIs stator resistance, i_d2When the angular speed of the stator is a second angular speed, the permanent magnet synchronous motor flows on a d axis i_q2When the angular speed of the stator is a second angular speed, the permanent magnet synchronous motor flows on a q axis, omega_tIs the second angular velocity, L_dIs a direct axis inductor, L_qIs a quadrature axis inductance,. psi_fIs a permanent magnet flux linkage, V_maxIs the maximum stator voltage amplitude.

Because the angular velocity of the stator of the permanent magnet synchronous motor cannot be infinitely increased, when the stator current vector of the permanent magnet synchronous motor moves to the current limit circle, the permanent magnet synchronous motor enters a third stage, namely, a constant power region. At this time, the current operating point of the permanent magnet synchronous motor needs to be controlled to be the intersection point of the voltage limit ellipse and the current limit circle. The stator voltage and the stator current amplitude of the permanent magnet synchronous motor in the region are both fixed and are respectively V_maxAnd I_max. The stator current vector is the intersection of the current limit circle and the voltage limit ellipse. That is, when the d-axis current of the PMSM is zero and the q-axis current is-I_maxIn the process, the output torque of the permanent magnet synchronous motor is zero, and the angular speed of the stator reaches the maximum.

Specifically, when the permanent magnet synchronous motor enters the third-stage constant power region, the maximum angular velocity ω of the stator of the permanent magnet synchronous motor can be determined through the voltage limit ellipse_maxNamely:

in the formula, V_maxIs the maximum stator voltage amplitude, R_sIs stator resistance, I_maxIs the current amplitude of the stator, #_fIs a permanent magnet flux linkage, L_dIs a direct axis inductor.

When the angular speed of the stator, the dq-axis current, the amplitude of the stator current and the output torque of the permanent magnet synchronous motor in a constant torque 1 area, a constant torque 2 area and a constant power area respectively are obtained through calculation, the traction characteristic diagram of the permanent magnet synchronous motor can be determined according to the parameters.

Obviously, the accuracy and reliability of the result created by the permanent magnet synchronous motor traction characteristic diagram can be further improved through the technical scheme provided by the embodiment.

Based on the above embodiments, the present embodiment further describes and optimizes the technical solution. Specifically, the steps are as follows: a process of determining a first angular velocity of a stator of a permanent magnet synchronous motor under a starting torque according to a voltage limit ellipse, and determining a first dq-axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular velocity of the stator is less than or equal to the first angular velocity, comprising:

and determining a first dq axis current and a first stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is less than or equal to the first angular speed by using the starting torque and maximum torque current ratio control formula.

In the present embodiment, when determining the first angular velocity of the stator of the permanent magnet synchronous motor at the starting torque, the voltage limit ellipse with the radius I is solved_max1The intersection point of the current circle and the maximum torque current ratio curve can determine the first angular speed omega of the permanent magnet synchronous motor in the constant torque 1 region_b。

Specifically, the voltage limiting ellipse has a radius of I_max1The intersection point of the current limit circle and the maximum torque current ratio curve is (i)_d1,i_q1) Wherein i is_d1D-axis current, i, for permanent magnet synchronous motor in constant torque 1 zone_q1The q-axis current of the permanent magnet synchronous motor in a constant torque 1 area is obtained. Then, the first angular velocity ω of the permanent magnet synchronous motor stator in the constant torque 1 region can be solved according to the voltage limit ellipse_b。

In other words, when the permanent magnet synchronous motor is in the constant torque 1 region, the angular velocity of the stator of the permanent magnet synchronous motor is low, and at the moment, only the stator current vector of the permanent magnet synchronous motor needs to be limited to be in the radius I_max1The angular speed of the stator of the permanent magnet synchronous motor can be solved when the angular speed is less than or equal to a first angular speed omega_bFirst dq-axis current i of time_d1And i_q1. When solving out i_d1And i_q1And then, the first stator current amplitude of the permanent magnet synchronous motor in the running state can be obtained.

Based on the above embodiments, the present embodiment further describes and optimizes the technical solution. Specifically, the steps are as follows: a process for determining a second dq-axis current and a second stator current magnitude for a permanent magnet synchronous machine, comprising:

and determining a second dq-axis current and a second stator current amplitude of the permanent magnet synchronous motor when the angular speed of the stator is greater than the first angular speed and less than or equal to a second angular speed by using the voltage limit ellipse and a constant torque curve of the permanent magnet synchronous motor.

When the angular speed of the stator of the permanent magnet synchronous motor is between the first angular speed and the second angular speed, the permanent magnet synchronous motor can operate in a constant torque 2 area, and under the state, the second dq axis current of the permanent magnet synchronous motor can be calculated by solving the intersection point of a constant torque curve and a voltage limit ellipse of the permanent magnet synchronous motor, namely:

in the formula, T_eTo output torque, N_pIs a logarithm of poles,. psi_fIs a permanent magnet flux linkage, L_dIs a direct axis inductor, L_qIs a quadrature axis inductor, i_dIs d-axis current, i_qIs q-axis current, R_sIs stator resistance, ω is angular velocity of the stator, V_maxIs the maximum stator voltage amplitude.

According to the formula of torque, cancel i_qThe above formula is simplified to relate to i_dThe d-axis current of the permanent magnet synchronous motor in the constant torque 2 area can be calculated by solving the equation and selecting a characteristic root meeting the following conditions.

In the formula (I), the compound is shown in the specification,is a real number set.

When the d-axis current of the permanent magnet synchronous motor in the constant torque 2 area is obtained through calculation, the q-axis current of the permanent magnet synchronous motor in the constant torque 2 area can be calculated by substituting the current value into a torque formula of the permanent magnet synchronous motor. After the current of the permanent magnet synchronous motor on the dq axis is obtained, the second stator current amplitude of the permanent magnet synchronous motor in the constant torque 2 area can be calculated.

Based on the above embodiments, this embodiment further describes and optimizes the technical solution, specifically, the steps are as follows: the process of determining a third dq-axis current, a third stator current amplitude and a target output torque of the permanent magnet synchronous motor when the angular velocity of the stator of the permanent magnet synchronous motor is greater than the second angular velocity and less than or equal to the maximum angular velocity includes:

and determining a third dq-axis current, a third stator current amplitude and a target output torque of the permanent magnet synchronous motor when the angular speed of the stator of the permanent magnet synchronous motor is greater than the second angular speed and less than or equal to the maximum angular speed by using the voltage limit ellipse, the current limit circle and a torque equation of the permanent magnet synchronous motor.

When the angular speed of the stator of the permanent magnet synchronous motor is at a second angular speed omega_tAnd maximum angular velocity ω_maxIn between, it is stated that the permanent magnet synchronous motor operates in the third-stage constant power region. At the moment, the third stator current amplitude I of the permanent magnet synchronous motor in the constant power region can be calculated by solving the intersection point of the voltage limit ellipse and the current limit circle_maxNamely:

in the formula i_dIs d-axis current, i_qIs q-axis current, I_maxIs the current amplitude of the stator, R_sIs stator resistance, ω is angular velocity of the stator, L_dIs a direct axis inductor, L_qIs a quadrature axis inductance,. psi_fIs a permanent magnet flux linkage, V_maxIs the maximum stator voltage amplitude.

When the permanent magnet synchronous motor operates in the area, the current vector of the permanent magnet synchronous motor is positioned in the second quadrant, and the third dq-axis current of the permanent magnet synchronous motor on the dq axis can be obtained according to the limiting condition.

Based on the technical content disclosed in the above embodiments, the present embodiment is described in detail by a specific example. It is assumed that the parameters of the permanent magnet synchronous machine are as shown in table 1.

TABLE 1

Firstly, the permanent magnet flux linkage psi of the permanent magnet synchronous motor can be calculated through the characteristic parameters of the permanent magnet synchronous motor_fI.e. the back emf coefficient of the permanent magnet synchronous machine.

Then, assume the starting torque T of the permanent magnet synchronous machine_{e_st}Calculating the starting current i of the permanent magnet synchronous motor for 1237N m_d1-90.5608A and i_q1175.0816A, and calculating the first angular speed omega of the stator of the permanent magnet synchronous motor in the constant torque 1 region_bSecond angular velocity ω in constant torque 2 region_tAnd a third angular velocity ω of the constant power region_max。

Wherein the first angular velocity of the stator of the permanent magnet synchronous motor is omega_b579.0427rad/s and a second angular velocity ω_t983.0272rad/s, third angular velocity ω_max＝5252.8078rad/s。

And finally, calculating the stator current of the permanent magnet synchronous motor in a constant torque 2 area, the dq axis current and the output torque of the permanent magnet synchronous motor in a constant power area, converting the angular speed of the stator into the train speed by using a target formula, and drawing a traction characteristic diagram of the permanent magnet synchronous motor. Referring to fig. 2, fig. 2 is a schematic diagram of a traction characteristic diagram of a permanent magnet synchronous motor according to an embodiment of the present invention.

Wherein, the expression of the target formula is:

v＝1.8ωD/i₀；

in the formula i₀For gear transmissionThe ratio, D is the wheel diameter in m and v is the train speed in km/h.

Referring to fig. 3, fig. 3 is a structural diagram of a traction characteristic determining apparatus of a permanent magnet synchronous motor according to an embodiment of the present invention, where the apparatus includes:

the parameter calculation module 21 is configured to determine a target operation parameter of the permanent magnet synchronous motor according to an attribute characteristic of the permanent magnet synchronous motor, and determine a parameter to be estimated in a traction characteristic diagram corresponding to the permanent magnet synchronous motor based on the voltage limit ellipse; the voltage limit ellipse is a model equation containing permanent magnet synchronous motor stator resistance;

and a characteristic map determination module 22 for determining a traction characteristic map using the target operating parameter and the parameter to be estimated.

The traction characteristic determination device of the permanent magnet synchronous motor provided by the embodiment of the invention has the beneficial effects of the disclosed traction characteristic determination method of the permanent magnet synchronous motor.

Referring to fig. 4, fig. 4 is a structural diagram of a traction characteristic determining apparatus of a permanent magnet synchronous motor according to an embodiment of the present invention, where the apparatus includes:

a memory 31 for storing a computer program;

a processor 32 for implementing the steps of a method for determining a traction characteristic of a permanent magnet synchronous machine as disclosed in the foregoing when executing a computer program.

The traction characteristic determination device of the permanent magnet synchronous motor provided by the embodiment of the invention has the beneficial effects of the disclosed traction characteristic determination method of the permanent magnet synchronous motor.

Accordingly, the embodiment of the present invention further discloses a computer readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for determining the traction characteristics of a permanent magnet synchronous motor as disclosed in the foregoing are implemented.

The computer-readable storage medium provided by the embodiment of the invention has the beneficial effects of the method for determining the traction characteristics of the permanent magnet synchronous motor disclosed in the foregoing.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The method, the device, the equipment and the medium for determining the traction characteristics of the permanent magnet synchronous motor provided by the invention are described in detail, a specific example is applied in the text to explain the principle and the implementation mode of the invention, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.