阅读说明：本技术 基于电压解耦的永磁同步电机转子位置检测系统及方法 (Permanent magnet synchronous motor rotor position detection system and method based on voltage decoupling ) 是由 张兵兵 魏海峰 张懿 王浩陈 于 2020-11-18 设计创作，主要内容包括：本发明公开了一种基于电压解耦的永磁同步电机转子位置检测系统及方法,属于永磁同步电机技术领域,其中检测方法包括：获取检测转子位置信息的信号；发出令电机旋转坐标系下交轴电流为零和直轴电流为零的控制指令；记录旋转变压器采集到的转子位置信息值；判断交轴电压和直轴电压是否已经完全解耦,若没有完全解耦,则根据直轴电压的正负性调整交轴电流的大小,重复检测；确定电机转子的位置。采用电压解耦确定永磁同步电机转子位置的方法,提高了获取转子位置的精确度,增强了电机的控制性能。(The invention discloses a system and a method for detecting the position of a permanent magnet synchronous motor rotor based on voltage decoupling, belonging to the technical field of permanent magnet synchronous motors, wherein the detection method comprises the following steps: acquiring a signal for detecting rotor position information; sending a control instruction for enabling quadrature axis current to be zero and direct axis current to be zero under a motor rotating coordinate system; recording a rotor position information value acquired by the rotary transformer; judging whether the quadrature axis voltage and the direct axis voltage are completely decoupled, if not, adjusting the magnitude of the quadrature axis current according to the positive and negative properties of the direct axis voltage, and repeatedly detecting; the position of the rotor of the motor is determined. The method for determining the position of the rotor of the permanent magnet synchronous motor by voltage decoupling improves the accuracy of obtaining the position of the rotor and enhances the control performance of the motor.)

1. A permanent magnet synchronous motor rotor position detection method based on voltage decoupling is characterized by comprising the following steps:

the method comprises the following steps: acquiring a detection signal, and sending a signal for detecting the position of the rotor to a motor controller to enable the motor to start a process of detecting the position of the rotor;

step two: acquiring an initial value of a position sensor, sending an instruction for enabling direct-axis current and quadrature-axis current under a motor rotating coordinate system to be zero to a motor controller, and recording the value of a rotary transformer at the moment as the value of the rough position of a rotor;

step three: the position detection method comprises the following specific steps: giving any fixed value to the quadrature axis current, and judging whether the direct axis voltage and the quadrature axis voltage are coupled under a motor rotating coordinate system; if the decoupling is complete, the current value of the rotary transformer is saved, and the detection process is exited; if the direct axis voltage is not completely decoupled, judging the positive and negative of the direct axis voltage, if the direct axis voltage is positive, reducing the quadrature axis current according to a certain step length, then judging whether the direct axis voltage is coupled with the quadrature axis voltage again, if the direct axis voltage is negative, increasing the quadrature axis current according to a certain step length, and then judging whether the direct axis voltage is coupled with the quadrature axis voltage again; repeating the steps until the direct-axis voltage and the quadrature-axis voltage are completely decoupled, storing the current value of the rotary transformer, and exiting the detection process;

step four: and adjusting the position, namely adjusting the position of the motor rotor according to the final value fed back by the rotary transformer to finish the detection of the accurate position of the permanent magnet synchronous motor rotor.

2. The method for detecting the position of the rotor of the permanent magnet synchronous motor based on voltage decoupling as claimed in claim 1, wherein a method for judging whether the voltage is decoupled is adopted to quickly detect the accurate position of the rotor of the permanent magnet synchronous motor.

3. The method for detecting the rotor position of the permanent magnet synchronous motor based on voltage decoupling as claimed in claim 1, wherein the quadrature axis current in the step three is any fixed value, and the value range of the fixed value is-20 to-100.

4. The method for detecting the rotor position of the permanent magnet synchronous motor based on voltage decoupling as claimed in claim 1, wherein in the third step, the quadrature axis current is increased or decreased according to a certain step length, and the value range of the step length is 0.1-5.

5. The method for detecting the rotor position of the permanent magnet synchronous motor based on voltage decoupling as claimed in claim 1, wherein the decoupling in the third step is to make the direct-axis current i_d0 and quadrature axis current i_qThe steady state equation for the direct axis voltage and quadrature axis voltage obtained is as follows:

the values of the direct-axis voltage and the quadrature-axis voltage are not influenced by the direct-axis current and the quadrature-axis current and are independent of each other.

6. The method for detecting the rotor position of the permanent magnet synchronous motor based on voltage decoupling according to claim 1, wherein the position of the motor rotor is adjusted in the fourth step, and a more accurate rotor position is obtained after direct-axis voltage and quadrature-axis voltage are completely decoupled on the basis of the position information of the rotary transformer obtained through rough measurement in the second step.

7. A permanent magnet synchronous motor rotor position detection system based on voltage decoupling is characterized by comprising: the device comprises a current processing module, a PI regulator module, a reverse Park conversion module, an SVPWM module, an inverter module, a Clark conversion module, a Park conversion module, a decoupling module, a rotary transformer information module and a permanent magnet synchronous motor;

the current processing module is connected with the PI regulator module and used for decomposing the combined current into a direct-axis current component and a quadrature-axis current component; the PI regulator module is respectively connected with the current processing module and the inverse Park conversion module and is used for regulating and controlling the direct-axis current component and the quadrature-axis current component; the inverse Park conversion module is connected with the PI regulator module and the SVPWM module and is used for converting direct-axis current and quadrature-axis current components into alpha-axis and beta-axis voltages; the SVPWM module is respectively connected with the inverse Park conversion module and the inverter module and is used for generating PWM waves from voltage vectors; the inverter module is respectively connected with the SVPWM module and the permanent magnet synchronous motor and is used for converting the three-phase current of the driving motor; the Clark conversion module is respectively connected with the inverter module and the Park conversion module and is used for converting three-phase current into direct-axis current component and quadrature-axis current component; the Park conversion module is connected with the Clark conversion module and is used for feeding back current components to the control loop; the decoupling module is respectively connected with the Park transformation module and the resolver information module and is used for compensating the rotor position information acquired by the resolver by using data obtained by voltage decoupling; the rotary transformer information module is connected with the permanent magnet synchronous motor and used for acquiring preliminary rotor position information.

Technical Field

The invention belongs to the technical field of permanent magnet synchronous motors, relates to a method for detecting the position of a rotor of a permanent magnet synchronous motor, and particularly relates to a system and a method for detecting the position of the rotor of the permanent magnet synchronous motor based on voltage decoupling.

Background

The permanent magnet synchronous motor has the advantages of high performance, high working density, excellent control characteristic, high reliability and the like. Therefore, the permanent magnet synchronous motor has been widely used in various industrial fields.

The permanent magnet synchronous motor for the new energy vehicle needs stable and accurate rotor position information to obtain higher control precision and quick transient response, and reliable and efficient operation of the motor is realized.

The rotor position deviation seriously affects the starting and control performance of the permanent magnet synchronous motor. In order to solve the problem, the existing position-free sensor method is a high-frequency signal injection method, wherein a high-frequency current signal is injected into a rotor position estimation mathematical model to indicate that the space position of a rotor is obtained; the position sensor is arranged to detect the position of the rotor by using a photoelectric encoder with position signal output. However, the former is generally complex and has high requirements on motor driving hardware; the latter has poor environment adaptation capability and more influence precision factors. The rotary transformer is high in reliability and has strong capability of resisting the external severe environment, and based on the characteristic that the voltage of the permanent magnet synchronous motor is not coupled under a certain condition, a high-precision rotor position detection system and a high-precision rotor position detection method can be designed.

Disclosure of Invention

The invention provides a method for detecting the position of a permanent magnet synchronous motor rotor based on voltage decoupling, which aims to solve the problem of inaccurate detection of the position of the permanent magnet synchronous motor rotor in the prior art.

The invention provides a voltage decoupling-based permanent magnet synchronous motor rotor position detection method, which is characterized by comprising the following steps of:

the method comprises the following steps: acquiring a detection signal, and sending a signal for detecting the position of the rotor to a motor controller to enable the motor to start a process of detecting the position of the rotor;

step two: acquiring an initial value of a position sensor, sending an instruction for enabling direct-axis current and quadrature-axis current under a motor rotating coordinate system to be zero to a motor controller, and recording the value of a rotary transformer at the moment as the value of the rough position of a rotor;

step three: the position detection method comprises the following specific steps: giving any fixed value to the quadrature axis current, and judging whether the direct axis voltage and the quadrature axis voltage are coupled under a motor rotating coordinate system; if the decoupling is complete, the current value of the rotary transformer is saved, and the detection process is exited; if the direct axis voltage is not completely decoupled, judging the positive and negative of the direct axis voltage, if the direct axis voltage is positive, reducing the quadrature axis current according to a certain step length, then judging whether the direct axis voltage is coupled with the quadrature axis voltage again, if the direct axis voltage is negative, increasing the quadrature axis current according to a certain step length, and then judging whether the direct axis voltage is coupled with the quadrature axis voltage again; repeating the steps until the direct-axis voltage and the quadrature-axis voltage are completely decoupled, storing the current value of the rotary transformer, and exiting the detection process;

step four: and adjusting the position, namely adjusting the position of the motor rotor according to the final value fed back by the rotary transformer to finish the detection of the accurate position of the permanent magnet synchronous motor rotor.

Optionally, the method for detecting the rotor position of the permanent magnet synchronous motor based on voltage decoupling is characterized in that a method for judging whether voltage is decoupled is adopted to quickly detect the accurate position of the rotor of the permanent magnet synchronous motor.

Optionally, any fixed value of the quadrature axis current in the third step is in a range of-20 to-100.

Optionally, in the third step, the quadrature axis current is increased or decreased according to a certain step length, and the value range of the step length is 0.1-5.

Optionally, the decoupling in step three is to make the direct-axis current i_d0 and quadrature axis current i_qThe steady state equation for the direct axis voltage and quadrature axis voltage obtained is as follows:

the values of the direct-axis voltage and the quadrature-axis voltage are not influenced by the direct-axis current and the quadrature-axis current and are independent of each other.

Optionally, the adjusting of the position of the motor rotor in the fourth step is to obtain a more accurate position of the rotor after the direct-axis voltage and the quadrature-axis voltage are completely decoupled on the basis of the position information of the resolver obtained through rough measurement in the second step.

The invention provides a permanent magnet synchronous motor rotor position detection system based on voltage decoupling, which is characterized by comprising the following components: the device comprises a current processing module, a PI regulator module, a reverse Park conversion module, an SVPWM module, an inverter module, a Clark conversion module, a Park conversion module, a decoupling module, a rotary transformer information module and a permanent magnet synchronous motor;

the current processing module is connected with the PI regulator module and used for decomposing the combined current into a direct-axis current component and a quadrature-axis current component; the PI regulator module is respectively connected with the current processing module and the inverse Park conversion module and is used for regulating and controlling the direct-axis current component and the quadrature-axis current component; the inverse Park conversion module is connected with the PI regulator module and the SVPWM module and is used for converting direct-axis current and quadrature-axis current components into alpha-axis and beta-axis voltages; the SVPWM module is respectively connected with the inverse Park conversion module and the inverter module and is used for generating PWM waves from voltage vectors; the inverter module is respectively connected with the SVPWM module and the permanent magnet synchronous motor and is used for converting the three-phase current of the driving motor; the Clark conversion module is respectively connected with the inverter module and the Park conversion module and is used for converting three-phase current into direct-axis current component and quadrature-axis current component; the Park conversion module is connected with the Clark conversion module and is used for feeding back current components to the control loop; the decoupling module is respectively connected with the Park transformation module and the resolver information module and is used for compensating the rotor position information acquired by the resolver by using data obtained by voltage decoupling; the rotary transformer information module is connected with the permanent magnet synchronous motor and used for acquiring preliminary rotor position information.

The invention at least comprises the following beneficial effects:

1. according to the invention, under the condition of not using additional driving hardware, the rotor position information is detected by simply utilizing the characteristic that the rotary transformer of the permanent magnet synchronous motor for the new energy vehicle is not coupled with the voltage of the motor, so that the control precision and the operation stability are improved.

2. According to the invention, the accurate position of the permanent magnet synchronous motor rotor is determined by combining the rough measurement of the rotary transformer and the voltage decoupling fine measurement of the rotor position information, so that the rotor position information can be rapidly and accurately obtained.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

fig. 1 is a flowchart of a method for detecting a rotor position of a permanent magnet synchronous motor based on voltage decoupling according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a voltage decoupling-based rotor position detection system of a permanent magnet synchronous motor according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. 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.

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

As shown in fig. 1, the invention provides a method for detecting a rotor position of a permanent magnet synchronous motor based on voltage decoupling, which is characterized by comprising the following steps:

step S1: acquiring a detection signal, and sending a signal for detecting the position of the rotor to a motor controller to enable the motor to start a process of detecting the position of the rotor;

step S2: acquiring an initial value of a position sensor, sending an instruction for enabling direct-axis current and quadrature-axis current under a motor rotating coordinate system to be zero to a motor controller, and recording the value of a rotary transformer at the moment as the value of the rough position of a rotor;

step S3: the position detection method comprises the following specific steps: giving any fixed value to the quadrature axis current, and judging whether the direct axis voltage and the quadrature axis voltage are coupled under a motor rotating coordinate system; if the decoupling is complete, the current value of the rotary transformer is saved, and the detection process is exited; if the direct axis voltage is not completely decoupled, judging the positive and negative of the direct axis voltage, if the direct axis voltage is positive, reducing the quadrature axis current according to a certain step length, then judging whether the direct axis voltage is coupled with the quadrature axis voltage again, if the direct axis voltage is negative, increasing the quadrature axis current according to a certain step length, and then judging whether the direct axis voltage is coupled with the quadrature axis voltage again; and repeating the steps until the direct-axis voltage and the quadrature-axis voltage are completely decoupled, storing the current value of the rotary transformer, and exiting the detection process.

Step S4: and adjusting the position, namely adjusting the position of the motor rotor according to the final value fed back by the rotary transformer to finish the detection of the accurate position of the permanent magnet synchronous motor rotor.

Optionally, the method for detecting the rotor position of the permanent magnet synchronous motor based on voltage decoupling is characterized in that a method for judging whether voltage is decoupled is adopted to quickly detect the accurate position of the rotor of the permanent magnet synchronous motor.

Optionally, in the first step, a signal of the rotor position is detected, and given by a software program, the detection instruction is assigned, and the detection function is called to start working.

Optionally, in the second step, the rotating coordinate system of the motor is a d-q synchronous rotating coordinate system, where the d axis is a straight axis and represents an excitation component, and the q axis is a quadrature axis and represents a moment component.

Optionally, the rotary transformer in the second step is a small ac motor for measuring angles, and can be used to measure position and speed information of a rotating object.

Optionally, the specific formulas of the direct axis voltage and the quadrature axis voltage in step three are as follows:

wherein, the 'U' is_d"is the direct axis voltage under the rotating coordinate system; 'U' is provided_q"is the quadrature axis voltage under the rotating coordinate system; "i_d"is the direct axis current in the rotating coordinate system; "i_q"is quadrature axis current under a rotating coordinate system; "L_d"is the direct axis inductance under the rotating coordinate system, and is a constant value quantity; "L_q"is quadrature axis inductance under the rotating coordinate system, and is a constant value quantity; "R_s"is the stator phase resistance of the motor, which is a constant value; 'psi' is the permanent magnet flux linkage of the motor, and is a constant value; ' omega_r"is the angular velocity of the rotor of the motor.

Optionally, any fixed value of the quadrature axis current in the third step ranges from-20 to-100.

Optionally, in the third step, the quadrature axis current is increased or decreased according to a certain step length, and the value range of the step length is 0.1-5.

Optionally, the decoupling in step three is to make the direct-axis current i_d0 and quadrature axis current i_qThe steady state equation for the direct axis voltage and quadrature axis voltage obtained is as follows:

the values of the direct-axis voltage and the quadrature-axis voltage are not influenced by the direct-axis current and the quadrature-axis current and are independent of each other.

Optionally, the adjusting of the position of the motor rotor in the fourth step is to obtain a more accurate position of the rotor after the direct-axis voltage and the quadrature-axis voltage are completely decoupled on the basis of the position information of the resolver obtained through rough measurement in the second step.

As shown in fig. 2, the present invention provides a schematic structural diagram of a system for detecting a rotor position of a permanent magnet synchronous motor based on voltage decoupling, including: the device comprises a current processing module, a PI regulator module, a reverse Park conversion module, an SVPWM module, an inverter module, a Clark conversion module, a Park conversion module, a decoupling module, a rotary transformer information module and a permanent magnet synchronous motor;

the current processing module is connected with the PI regulator module and used for decomposing the combined current into a direct-axis current component and a quadrature-axis current component; the PI regulator module is respectively connected with the current processing module and the inverse Park conversion module and is used for regulating and controlling the direct-axis current component and the quadrature-axis current component; the inverse Park conversion module is connected with the PI regulator module and the SVPWM module and is used for converting direct-axis current and quadrature-axis current components into alpha-axis and beta-axis voltages; the SVPWM module is respectively connected with the inverse Park conversion module and the inverter module and is used for generating PWM waves from voltage vectors; the inverter module is respectively connected with the SVPWM module and the permanent magnet synchronous motor and is used for converting the three-phase current of the driving motor; the Clark conversion module is respectively connected with the inverter module and the Park conversion module and is used for converting three-phase current into direct-axis current component and quadrature-axis current component; the Park conversion module is connected with the Clark conversion module and is used for feeding back current components to the control loop; the decoupling module is respectively connected with the Park transformation module and the resolver information module and is used for compensating the rotor position information acquired by the resolver by using data obtained by voltage decoupling; the rotary transformer information module is connected with the permanent magnet synchronous motor and used for acquiring preliminary rotor position information.

It is obvious that those skilled in the art can obtain various effects not directly mentioned according to the respective embodiments without trouble from various structures according to the embodiments of the present invention. While embodiments of the invention have been disclosed above, it is not intended to be limited to the uses set forth in the specification and examples. It can be applied to all kinds of fields suitable for the present invention. Additional modifications will readily occur to those skilled in the art. It is therefore intended that the invention not be limited to the exact details and illustrations described and illustrated herein, but fall within the scope of the appended claims and equivalents thereof.