Method and device for acquiring initial position of switch Hall based on high-frequency rotating pulse

Abstract

The present invention relates to a switch Hall initial position acquisition method and device based on high-frequency rotating pulses, comprising: converting the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval; dividing the rotor angle interval into 1024 equal parts, constructing the corresponding angle value, generating a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz; generating a PWM pulse for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq; converting the currents IA, IB, and IC collected on the three-phase line of the permanent magnet synchronous motor into Id and Iq currents in a synchronous rotating coordinate system; recording the current angle value and Id current at the falling edge of the Ud pulse voltage, and finally obtaining the angle value of the current rotor initial position by calculation. Compared with the prior art, the present invention can obtain the accurate angle value of the current permanent magnet synchronous motor rotor initial position.

Description

Technical Field

[0001] The invention relates to the field of permanent magnet synchronous motors, and in particular to a method and a device for acquiring a switch Hall initial position based on a high-frequency rotating pulse. Background Art

[0002] Permanent magnet synchronous motor (PMSM) has been widely used in the field of new energy vehicles in recent years. Its advantages such as high efficiency, high power density and low torque pulsation have been favored by customers. In order to further reduce the cost of permanent magnet synchronous motors, many motors on the market use switch Hall as rotor position sensor. Since the six sets of Hall code can only represent the angle range of Π / 3 of the electrical angle, there is no accurate starting angle position, which will cause starting jitter or even loss of control. Therefore, how to process the signal output by the switch Hall and estimate the initial position angle of the rotor more accurately has become a current research hotspot. Summary of the invention

[0003] The purpose of the present invention is to overcome the defect of the above-mentioned prior art that when the rotor is stationary, the acceleration and angular acceleration are both 0, so the rotor position cannot be calculated using the traditional angle estimation method, and to provide a method and device for obtaining the initial position of the switch Hall based on high-frequency rotating pulses.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A method for acquiring the initial position of a switch Hall based on a high-frequency rotating pulse comprises the following steps:

[0006] Switch Hall sensor analysis steps: convert the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval;

[0007] High-frequency rotation pulse generation steps: divide the rotor angle interval into 1024 equal parts, construct the corresponding angle value, and generate a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz;

[0008] SVPWM vector modulation step: generating PWM pulses for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq;

[0009] CLARK_PARK operation steps: convert the currents IA, IB, and IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system;

[0010] Recording steps: According to the falling edge moment of the Ud pulse voltage, record the current angle value and Id current, and finally obtain the angle value of the current rotor initial position through calculation.

[0011] Furthermore, in the switch Hall sensor parsing step, 0 and 1 are used to represent the level state of the switch Hall sensor, and the switch Hall sensor of the synchronous motor includes three switch Halls, namely HA, HB and HC;

[0012] When the switch status of HA, HB, and HC is 101, the position interval range is ThetaL=0, ThetaH=60;

[0013] When the switch status of HA, HB, and HC is 100, the position interval range is ThetaL=60, ThetaH=120;

[0014] When the switch status of HA, HB, and HC is 110, the position interval range is ThetaL=120, ThetaH=180;

[0015] When the switch status of HA, HB, and HC is 010, the position interval range is ThetaL=180, ThetaH=240;

[0016] When the switch status of HA, HB, and HC is 011, the position interval range is ThetaL=240, ThetaH=300;

[0017] When the switch status of HA, HB, and HC is 001, the position interval range is ThetaL=300, ThetaH=360.

[0018] Furthermore, in the high-frequency rotating pulse generating step, the output angle value Theta=ThetaL+60*r / 1024, wherein r is taken from 0, 1, 2, ...1023, 1024 respectively.

[0019] Furthermore, in the CLARK_PARK operation step, the calculation expressions of Id and Iq currents are respectively:

[0020] Id=IA*Cos(Theta)+(IA+2IB)*Sin(Theta) / 1.732

[0021] Iq=-IA*Sin(Theta)+(IA+2IB)*Cos(Theta) / 1.732

[0022] Where Theta is the angle value.

[0023] Furthermore, in the recording step, (r0, Id0), (r1, Id1), ..., (r1023, Id1023), (r1024, Id1024) are recorded; after the high-frequency rotating pulse voltage scan is completed, the maximum value position MAX (Id0, Id1, ..., Id1023, Id1024) of the absolute value of Id is retrieved, and the corresponding angle value is the precise value of the initial position of the rotor of the permanent magnet synchronous motor.

[0024] The present invention also provides a switch Hall initial position acquisition device based on high-frequency rotating pulses, comprising:

[0025] Switch Hall sensor parsing module. It is used to convert the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval;

[0026] The high-frequency rotating pulse generating module is used to divide the rotor angle interval into 1024 equal parts, construct the corresponding angle value, and transmit the angle value, Ud pulse square wave voltage and Uq pulse square wave voltage to the SVPWM vector modulation module by generating a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz;

[0027] An SVPWM vector modulation module is used to generate PWM pulses for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq;

[0028] CLARK_PARK operation module, used to convert the currents IA, IB, IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system;

[0029] The recording module is used to record the current angle value and Id current according to the falling edge moment of the Ud pulse voltage, and finally obtain the angle value of the current rotor initial position through calculation.

[0030] Further, the switch Hall sensor parsing module represents the level state of the switch Hall sensor with 0 and 1, and the switch Hall sensor of the synchronous motor includes three switch Halls, namely HA, HB and HC;

[0031] When the switch status of HA, HB, and HC is 101, the position interval range is ThetaL=0, ThetaH=60;

[0032] When the switch status of HA, HB, and HC is 100, the position interval range is ThetaL=60, ThetaH=120;

[0033] When the switch status of HA, HB, and HC is 110, the position interval range is ThetaL=120, ThetaH=180;

[0034] When the switch status of HA, HB, and HC is 010, the position interval range is ThetaL=180, ThetaH=240;

[0035] When the switch status of HA, HB, and HC is 011, the position interval range is ThetaL=240, ThetaH=300;

[0036] When the switch status of HA, HB, and HC is 001, the position interval range is ThetaL=300, ThetaH=360.

[0037] Furthermore, the high-frequency rotation pulse generating module outputs an angle value Theta=ThetaL+60*r / 1024, wherein r is taken from 0, 1, 2, ..., 1023, 1024 respectively.

[0038] Furthermore, in the CLARK_PARK operation module, the calculation expressions of Id and Iq currents are respectively:

[0039] Id=IA*Cos(Theta)+(IA+2IB)*Sin(Theta) / 1.732

[0040] Iq=-IA*Sin(Theta)+(IA+2IB)*Cos(Theta) / 1.732

[0041] Where Theta is the angle value.

[0042] Furthermore, in the recording module, (r0, Id0), (r1, Id1), ..., (r1023, Id1023), (r1024, Id1024) are recorded; after the high-frequency rotating pulse voltage scan is completed, the maximum value position MAX (Id0, Id1, ..., Id1023, Id1024) of the absolute value of Id is retrieved, and the corresponding angle value is the precise value of the initial position of the rotor of the permanent magnet synchronous motor.

[0043] Compared with the prior art, the present invention has the following advantages:

[0044] Compared with other types of rotor position sensors, the use of switch Hall as the rotor position sensor of permanent magnet synchronous motor is relatively cheap and has a wide range of applications. However, since the acceleration and angular acceleration are both 0 when the rotor is stationary, the rotor position cannot be calculated using the traditional angle estimation method.

[0045] Therefore, in order to better solve the above problems, the present invention proposes a switch Hall initial position acquisition method based on high-frequency rotating pulses. In this method, when the motor is in a stationary state, the three switch Hall sensors HA, HB, and HC input high and low level signals to the Hall code analysis module to analyze the angle range to obtain ThetaH and ThetaL. The high-frequency voltage generation module divides the angle range generated by the angle analysis module into 1024 smaller angle range intervals, and generates a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz, and a Uq DC voltage with a duty cycle of 0% and a frequency of 6.25kHz. After the angle Theta and the Ud pulse voltage are modulated by the SVPWM space vector, the three-phase current of the motor is collected, and the three-phase currents Ia, Ib, and Ic are converted into Id and Iq currents after Clark and Park transformation. Record the Theta value at the falling edge of Ud and the sampled Id value, find the Theta value corresponding to the maximum value of |Id|, and calculate to obtain the precise angle value of the current rotor initial position. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of a switch Hall initial position acquisition method based on high-frequency rotating pulses provided in an embodiment of the present invention;

[0047] Figure 2 The present invention provides an operation flow chart of a method for obtaining the initial position of a switch Hall based on a high-frequency rotating pulse in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0051] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0052] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0053] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0054] Example 1

[0055] like Figure 1 and 2 As shown, this embodiment provides a method for obtaining the initial position of a switch Hall based on a high-frequency rotating pulse, comprising the following steps:

[0056] Switch Hall sensor analysis steps: convert the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval;

[0057] High-frequency rotation pulse generation steps: divide the rotor angle interval into 1024 equal parts, construct the corresponding angle value, and generate a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz;

[0058] SVPWM vector modulation step: generating PWM pulses for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq;

[0059] CLARK_PARK operation steps: convert the currents IA, IB, and IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system;

[0060] Recording steps: According to the falling edge moment of the Ud pulse voltage, record the current angle value and Id current, and finally obtain the angle value of the current rotor initial position through calculation.

[0061] Specifically, in the switch Hall sensor parsing step, 0 and 1 are used to represent the level state of the switch Hall sensor, and the switch Hall sensor of the synchronous motor includes three switch Halls, namely HA, HB and HC;

[0062] When the switch status of HA, HB, and HC is 101, the position interval range is ThetaL=0, ThetaH=60;

[0063] When the switch status of HA, HB, and HC is 100, the position interval range is ThetaL=60, ThetaH=120;

[0064] When the switch status of HA, HB, and HC is 110, the position interval range is ThetaL=120, ThetaH=180;

[0065] When the switch status of HA, HB, and HC is 010, the position interval range is ThetaL=180, ThetaH=240;

[0066] When the switch status of HA, HB, and HC is 011, the position interval range is ThetaL=240, ThetaH=300;

[0067] When the switch status of HA, HB, and HC is 001, the position interval range is ThetaL=300, ThetaH=360.

[0068] In the high-frequency rotating pulse generation step, the angle interval is divided into 1024 equal parts, and the output angle value Theta = ThetaL + 60*r / 1024, where r is 0, 1, 2, ... 1023, 1024. Ud is a square wave pulse voltage with a duty cycle of 50% and a frequency of 6.25kHz, and Uq is a square wave pulse voltage with a duty cycle of 0% and a frequency of 6.25kHz. Ud and Uq are input into the SVPWM vector modulation module with the angle value Theta.

[0069] SVPWM calculates the input angle and voltage values ​​of Ud and Uq to generate PWM pulses (PWMA, PWMB, PWMC) that drive the permanent magnet synchronous motor.

[0070] In the CLARK_PARK operation step, the phase current IAIBIC is collected and the angle value Theta is used for CLARK_PARK transformation to obtain the Id and Iq currents, where: Id = IA*Cos(Theta)+(IA+2IB)*Sin(Theta) / 1.732; Iq = -IA*Sin(Theta)+(IA+2IB)*Cos(Theta) / 1.732. The falling edge trigger record of the voltage of the Ud square wave pulse is obtained.

[0071] Record the angle value r at the current triggering moment and the current Id current value of the permanent magnet synchronous motor, record (r0, Id0), (r1, Id1), ..., (r1023, Id1023), (r1024, Id1024). After the high-frequency rotating pulse voltage scan is completed, retrieve the maximum position of the absolute value of Id MAX (Id0, Id1, ..., Id1023, Id1024), and the corresponding angle value is the precise value of the initial position of the rotor of the permanent magnet synchronous motor (ThetaInit).

[0072] This embodiment also provides a switch Hall initial position acquisition device based on high-frequency rotating pulses, comprising:

[0073] Switch Hall sensor parsing module. It is used to convert the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval;

[0074] The high-frequency rotating pulse generating module is used to divide the rotor angle interval into 1024 equal parts, construct the corresponding angle value, and transmit the angle value, Ud pulse square wave voltage and Uq pulse square wave voltage to the SVPWM vector modulation module by generating a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz;

[0075] An SVPWM vector modulation module is used to generate PWM pulses for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq;

[0076] CLARK_PARK operation module, used to convert the currents IA, IB, IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system;

[0077] The recording module is used to record the current angle value and Id current according to the falling edge moment of the Ud pulse voltage, and finally obtain the angle value of the current rotor initial position through calculation.

[0078] The switch Hall sensor analysis module mainly converts the high and low level Hall codes generated by the switch Hall into the corresponding permanent magnet synchronous motor rotor angle range (ThetaL, ThetaH).

[0079] The high-frequency rotating pulse generating module mainly divides the angle interval into 1024 angles (Theta) with higher precision, and generates a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz, and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz.

[0080] The SVPWM vector modulation module mainly accepts high-precision angles and voltage values ​​of Ud and Uq, and generates PWM pulses (PWMA, PWMB, PWMC) to drive the permanent magnet synchronous motor through calculation. The CLARK_PARK calculation module mainly converts the currents IA, IB, and IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system.

[0081] The recording module mainly records the current rotation angle (Theta) and Id current at the falling edge of the Ud pulse voltage, and finally obtains the precise angle value of the current rotor initial position through calculation.

[0082] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for obtaining the initial position of a switch Hall based on a high-frequency rotating pulse, characterized in that: The following steps are involved: Switch Hall sensor analysis steps: convert the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval; High-frequency rotation pulse generation steps: divide the rotor angle interval into 1024 equal parts, construct the corresponding angle value, generate a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz, and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz; SVPWM vector modulation step: generating PWM pulses for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq; CLARK_PARK operation steps: convert the currents IA, IB, and IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system; Recording steps: According to the falling edge of the Ud pulse voltage, record the current angle value and Id current, and finally obtain the angle value of the current rotor initial position through calculation; In the switch Hall sensor parsing step, 0 and 1 are used to represent the level state of the switch Hall sensor. The switch Hall sensor of the synchronous motor includes three switch Halls, namely HA, HB and HC. When the switch status of HA, HB, and HC is 101, the position interval range is ThetaL=0, ThetaH=60; When the switch status of HA, HB, and HC is 100, the position interval range is ThetaL=60, ThetaH=120; When the switch status of HA, HB, and HC is 110, the position interval range is ThetaL=120, ThetaH=180; When the switch status of HA, HB, and HC is 010, the position interval range is ThetaL=180, ThetaH=240; When the switch status of HA, HB, and HC is 011, the position interval range is ThetaL=240, ThetaH=300; When the switch status of HA, HB, and HC is 001, the position interval range is ThetaL=300, ThetaH=360; In the high-frequency rotating pulse generating step, the output angle value Theta=ThetaL+60*r / 1024, wherein r is taken from 0, 1, 2, ...1023, 1024 respectively.

2. The method for obtaining the initial position of a switch Hall based on a high-frequency rotating pulse according to claim 1, characterized in that: In the CLARK_PARK operation step, the calculation expressions of Id and Iq currents are respectively: Id=IA*Cos(Theta)+(IA+2IB)*Sin(Theta) / 1.732 Iq=-IA*Sin(Theta)+(IA+2IB)*Cos(Theta) / 1.732 Where Theta is the angle value.

3. The method for obtaining the initial position of a switch Hall based on a high-frequency rotating pulse according to claim 1, characterized in that: In the recording step, (r0, Id0), (r1, Id1), ..., (r1023, Id1023), (r1024, Id1024) are recorded; after the high-frequency rotating pulse voltage scan is completed, the maximum value position MAX (Id0, Id1, ..., Id1023, Id1024) of the absolute value of Id is retrieved, and the corresponding angle value is the precise value of the initial position of the rotor of the permanent magnet synchronous motor.

4. A switch Hall initial position acquisition device based on high-frequency rotating pulse, characterized in that: include: The switch Hall sensor analysis module is used to convert the high and low level Hall codes generated by the switch Hall sensor of the synchronous motor into the corresponding permanent magnet synchronous motor rotor angle interval; A high-frequency rotating pulse generating module is used to divide the rotor angle interval into 1024 equal parts, construct the corresponding angle value, generate a Ud pulse square wave voltage with a duty cycle of 50% and a frequency of 6.25kHz, and a Uq pulse square wave voltage with a duty cycle of 0% and a frequency of 6.25kHz, and transmit the angle value, Ud pulse square wave voltage and Uq pulse square wave voltage to the SVPWM vector modulation module; An SVPWM vector modulation module is used to generate PWM pulses for driving the permanent magnet synchronous motor by calculating the angle value and the voltage values ​​of Ud and Uq; CLARK_PARK operation module, used to convert the currents IA, IB, IC collected on the three-phase lines of the permanent magnet synchronous motor into Id and Iq currents in the synchronous rotating coordinate system; The recording module is used to record the current angle value and Id current according to the falling edge of the Ud pulse voltage, and finally obtain the angle value of the current rotor initial position through calculation; The switch Hall sensor analysis module represents the level state of the switch Hall sensor with 0 and 1. The switch Hall sensor of the synchronous motor includes three switch Halls, namely HA, HB and HC; When the switch status of HA, HB, and HC is 101, the position interval range is ThetaL=0, ThetaH=60; When the switch status of HA, HB, and HC is 100, the position interval range is ThetaL=60, ThetaH=120; When the switch status of HA, HB, and HC is 110, the position interval range is ThetaL=120, ThetaH=180; When the switch status of HA, HB, and HC is 010, the position interval range is ThetaL=180, ThetaH=240; When the switch status of HA, HB, and HC is 011, the position interval range is ThetaL=240, ThetaH=300; When the switch status of HA, HB, and HC is 001, the position interval range is ThetaL=300, ThetaH=360; The angle value Theta output by the high-frequency rotation pulse generating module is Theta=ThetaL+60*r / 1024, wherein r is selected from 0, 1, 2, ..., 1023, 1024 respectively.

5. The switch Hall initial position acquisition device based on high-frequency rotating pulse according to claim 4 is characterized in that: In the CLARK_PARK operation module, the calculation expressions of Id and Iq currents are respectively: Id=IA*Cos(Theta)+(IA+2IB)*Sin(Theta) / 1.732 Iq=-IA*Sin(Theta)+(IA+2IB)*Cos(Theta) / 1.732 Where Theta is the angle value.

6. The switch Hall initial position acquisition device based on high-frequency rotating pulse according to claim 4 is characterized in that: In the recording module, (r0, Id0), (r1, Id1), ..., (r1023, Id1023), (r1024, Id1024) are recorded; after the high-frequency rotating pulse voltage scan is completed, the maximum value position MAX (Id0, Id1, ..., Id1023, Id1024) of the absolute value of Id is retrieved, and the corresponding angle value is the precise value of the initial position of the rotor of the permanent magnet synchronous motor.

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