A method and system for judging the initial state of a permanent magnet synchronous motor drive system

Abstract

The present invention discloses a method and system for judging the initial state of a permanent magnet synchronous motor drive system, belonging to the technical field of automatic control. Fix θ = 0 to make the α-β axis of the permanent magnet synchronous motor coincide with the d-q axis, where θ represents the position signal; use voltage open-loop control to output voltage vectors with different voltage angles, and at this time, the d-q axis current angle is consistent with the voltage angle; judge the initial state of the permanent magnet synchronous motor drive system according to the duty cycle in the SVPWM output register, the signals of the upper and lower bridges of the three phases of the logic board, the magnitude and direction of the current in each phase of the three-phase line, the numerical value of the current sensor AD sampling in the motor controller, the current value calculated by the motor controller, the resolver sampling value and the corresponding angle. Through the present invention, the verification and judgment of the basic signals required for the normal operation of the motor drive system such as the motor, the software and hardware (logic board, drive board) of the controller can be quickly and accurately completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic control, and more specifically, relates to a method and system for judging the initial state of a permanent magnet synchronous motor drive system. Background Art

[0002] Before leaving the factory, the motor and the controller will undergo offline detection. However, due to factors such as the assembly accuracy and the non-uniformity of the motor magnetic field, there may be certain differences in the initial state of the motor drive system. At the same time, before the newly developed motor and controller start the test, the drive system needs to determine the initial state to ensure the matching of relevant signals of the motor and the motor controller (software and hardware). Therefore, the judgment of the initial state of the permanent magnet synchronous motor drive system is an indispensable part of the development cycle of the electric drive system, including the calculation and judgment of parameters such as drive signals, dead time, current sensor sampling accuracy and current direction, motor zero position compensation value, and rotation direction.

[0003] Referring to the patent application CN106301133A, a voltage vector output unit is used to output voltage vectors with current angles of 0°, 60°, 120°, 180°, 240°, and 300°. A resolver angle acquisition module is used to acquire the resolver angles corresponding to different voltage angles, and the motor zero position value is calculated by taking the average value. The above solution is only used to calculate the zero position value and does not perform other initial state judgments. There is an angle between the d-q axis and the α-β axis, and it is relatively abstract and not intuitive enough when performing other initial state judgments. Only the resolver angles corresponding to 6 fixed-angle voltage vectors are collected, and the accuracy may not meet the requirements, and the limitation is relatively strong.

[0004] Referring to the patent application CN101262194B, a direct current is applied to the A and B phases of the motor to position the motor at an initial angle; the motor controller collects the motor position signal and transmits the read position signal value to the motor position variable; the current sensor is calibrated by applying a positive-direction current: the calibration algorithm in the controller records the current in the positive direction of the phase where the current sensor is located, and then applies a reverse current, and the calibration quantity of the current sensor is obtained by comparing the two values. Using the above technical solution, the motor magnetic field may not be uniform, the motor zero position test accuracy is relatively poor, and only the positive and negative two currents are used to calibrate the current sensor, so the calibration accuracy of the current sensor is relatively poor. Summary of the Invention

[0005] In view of the above defects or improvement requirements of the prior art, the present invention proposes a method and system for judging the initial state of a permanent magnet synchronous motor drive system, which can quickly and accurately complete the verification and judgment of the basic signals required for the normal operation of the motor drive system, such as the software and hardware (logic board, drive board) of the motor and the controller.

[0006] To achieve the above object, according to one aspect of the present invention, a method for judging the initial state of a permanent magnet synchronous motor drive system is provided, including:

[0007] (1) Fix θ = 0 to make the α-β axis of the permanent magnet synchronous motor coincide with the d-q axis, where θ represents the position signal;

[0008] (2) Use voltage open-loop control to output voltage vectors with different voltage angles. At this time, the d-q axis current angle is consistent with the voltage angle;

[0009] (3) Judge the initial state of the permanent magnet synchronous motor drive system according to the duty ratio in the SVPWM output register, the signals of the upper and lower bridge arms of the three phases of the logic board, the magnitude and direction of the current in each phase of the three-phase line, the value sampled by the current sensor AD in the motor controller, the current value calculated by the motor controller, the resolver sampling value and the corresponding angle.

[0010] In some alternative embodiments, step (3) includes:

[0011] (3.1) Judge whether the duty ratio value in the SVPWM output register and the signals of the upper and lower bridge arms of the three phases of the logic board correspond to the voltage vector of the input voltage angle;

[0012] (3.2) Judge whether the magnitude and direction of the current calculated by the motor controller are consistent with the magnitude and direction of the current in each phase of the three-phase line measured by the oscilloscope, and whether the current sampling accuracy meets the relevant requirements;

[0013] (3.3) Record the resolver sampling value and the corresponding angle;

[0014] (3.4) Use voltage open-loop control to change the voltage vector of the output voltage angle, and repeat steps (3.1) to (3.3) until the number of collected voltage angles meets the accuracy requirements.

[0015] In some alternative embodiments, after the number of collected voltage angles meets the accuracy requirements, the method further includes:

[0016] Judge whether the change of the resolver output angle corresponds to the input voltage angle, and whether the motor rotation direction corresponds to the resolver output signal;

[0017] Calculate the motor zero position compensation value using each group of voltage angles and the corresponding resolver angles.

[0018] In some alternative embodiments, use the oscilloscope probe and the oscilloscope to read the signals of the upper and lower bridge arms of the three phases of the logic board.

[0019] In some alternative embodiments, use the current clamp and the oscilloscope to read the magnitude and direction of the current in each phase of the three-phase line.

[0020] According to another aspect of the present invention, there is provided a system for judging the initial state of a permanent magnet synchronous motor drive system, including: a PMSM motor, a motor controller, a host computer, an oscilloscope, and a test device;

[0021] The motor controller is used to fix θ = 0 of the PMSM motor to make the α-β axis of the permanent magnet synchronous motor coincide with the d-q axis, where θ represents the position signal; and use voltage open-loop control to output voltage vectors with different voltage angles, at this time, the d-q axis current angle is consistent with the voltage angle;

[0022] Read the duty cycle in the SVPWM output register through the host computer, and read the signals of the upper and lower bridge arms of the three phases of the logic board and the magnitude and direction of the current in each phase of the three-phase line through the oscilloscope and the test device;

[0023] The host computer is further used to judge the initial state of the permanent magnet synchronous motor drive system according to the duty cycle in the SVPWM output register, the signals of the upper and lower bridge arms of the three phases of the logic board, the magnitude and direction of the current in each phase of the three-phase line, the numerical value of the current sensor AD sampling in the motor controller, the current value calculated by the motor controller, the resolver sampling value, and the corresponding angle.

[0024] In some alternative embodiments, the host computer is used to judge whether the duty cycle value in the SVPWM output register and the signals of the upper and lower bridge arms of the three phases of the logic board correspond to the voltage vector of the input voltage angle; judge whether the magnitude and direction of the current calculated by the motor controller are consistent with the magnitude and direction of the current in each phase of the three-phase line measured by the oscilloscope, and whether the current sampling accuracy meets the relevant requirements; record the resolver sampling value and the corresponding angle; use voltage open-loop control to change the voltage vector of the output voltage angle, and repeat the above operations until the number of collected voltage angles has met the accuracy requirements.

[0025] In some alternative embodiments, after the number of collected voltage angles has met the accuracy requirements, the host computer is further used to judge whether the change in the resolver output angle corresponds to the input voltage angle, and whether the motor rotation direction corresponds to the resolver output signal; calculate the motor zero position compensation value using each group of voltage angles and the corresponding resolver angles.

[0026] In some alternative embodiments, use the oscilloscope probe and the oscilloscope to read the signals of the upper and lower bridge arms of the three phases of the logic board.

[0027] In some alternative embodiments, use a current clamp and an oscilloscope to read the magnitude and direction of the current in each phase of the three-phase line.

[0028] Generally speaking, compared with the prior art by the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

[0029] Fix θ = 0 to align the α-β axis with the d-q axis, facilitating subsequent analysis. Use voltage open-loop control to output voltage vectors with different voltage angles. At this time, the d-q axis current angle is consistent with the voltage angle, and at the same time, calculations and judgments of parameters such as drive signals, dead time, current sensor sampling accuracy and current direction, motor zero position compensation value, and rotation direction are completed. The present invention can quickly and accurately verify and judge the basic signals required for the normal operation of the motor drive system, such as the motor, controller software, and hardware (logic board, drive board), through only one experiment. The operation is simple, and the judgment method is intuitive and clear, which can prepare for various tests such as motor calibration and performance testing in advance. Brief Description of the Drawings

[0030] Figure 1 is a schematic diagram of various physical quantities of a motor provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic flow diagram of a method for judging the initial state of a permanent magnet synchronous motor drive system provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of a system for judging the initial state of a permanent magnet synchronous motor drive system provided by an embodiment of the present invention. Detailed Embodiments

[0033] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] In the embodiment of the present invention, the quadrature axis: also known as the d axis. As Figure 1 shown, the d axis is defined as the direction of the N pole of the rotor magnetic pole of the permanent magnet synchronous motor;

[0035] The direct axis: also known as the q axis. As Figure 1 shown, the q axis is defined as the direction of rotating 90° counterclockwise from the positive direction of the d axis;

[0036] The α axis: as Figure 1 shown, the α axis is defined in the 0° direction;

[0037] The β axis: as Figure 1 shown, the β axis is defined in the 90° direction;

[0038] The position signal: as Figure 1 shown, the angle between the α axis and the d axis;

[0039] The quadrature axis inductance: also known as the d axis inductance, Ld;

[0040] Direct-axis inductance: Also known as q-axis inductance, Lq;

[0041] Alpha-axis inductance: Also known as d-axis inductance, Lα;

[0042] Beta-axis inductance: Also known as q-axis inductance, Lβ;

[0043] Alpha-axis voltage: Vα;

[0044] Beta-axis voltage: Vβ;

[0045] Alpha-axis current: iα;

[0046] Beta-axis current: iβ;

[0047] D-axis voltage: Vd;

[0048] Q-axis voltage: Vq;

[0049] D-axis current: id;

[0050] Q-axis current: iq;

[0051] LCR: Inductor, capacitor, resistor.

[0052] As Figure 2 shown, it is a schematic flowchart of a method for judging the initial state of a permanent magnet synchronous motor drive system provided by an embodiment of the present invention. The process of judging the initial state of the permanent magnet synchronous motor drive system is as follows:

[0053] 1) Fix θ = 0. At this time, the α-β axis of the permanent magnet synchronous motor coincides with the d-q axis, which is convenient for judging the motor drive signal and the corresponding relationship of each sector;

[0054] 2) Use voltage open-loop control to output voltage vectors with different voltage angles (the voltage angle can be any value from 0 to 360°). The voltage modulus is set as required. At this time, the d-q axis current angle is consistent with the voltage angle, and the current magnitude is related to the voltage modulus and the voltage given by the battery simulator. After the voltage vector is output, the motor rotor will rotate to a certain fixed position and stabilize under the action of the magnetic field force. This position is related to the input voltage angle;

[0055] 3) Use the host computer to read the duty cycle value in the SVPWM output register;

[0056] 4) Use the oscilloscope probe and oscilloscope to read the signals of the upper and lower bridges of the three phases of the logic board;

[0057] 5) Judge whether the duty cycle value and the three-phase upper and lower bridge signals correspond to the input voltage vector;

[0058] 6) Use the current clamp and oscilloscope to read the magnitude and direction of the current in each phase of the three-phase line;

[0059] 7) The host computer reads the value sampled by the current sensor AD in the controller and the current value calculated by the controller.

[0060] 8) Determine whether the magnitude and direction of the current calculated by the controller are consistent with the data measured by the oscilloscope, and whether the current sampling accuracy meets the relevant requirements.

[0061] 9) Record the resolver sampling value and the corresponding angle at this time.

[0062] 10) Repeat steps 2 - 9 until the number of voltage angles collected meets the accuracy requirements.

[0063] 11) Determine whether the change in the resolver output angle corresponds to the input voltage angle, and whether the motor rotation direction corresponds to the resolver output signal.

[0064] 12) Calculate the motor zero - position compensation value using each group of voltage angles and the corresponding resolver angles.

[0065] As Figure 3 shown, it is a schematic diagram of a system for judging the initial state of a permanent - magnet synchronous motor drive system provided by an embodiment of the present invention. The system for judging the initial state of a permanent - magnet synchronous motor drive system consists of a PMSM motor, a motor controller, a host computer, an oscilloscope, a low - voltage power supply / battery, a battery simulator / power battery, and a test device (current clamp, oscilloscope, oscilloscope probe), etc.

[0066] The motor controller is used to fix θ = 0 of the PMSM motor so that the α - β axis of the permanent - magnet synchronous motor coincides with the d - q axis, where θ represents the position signal; it uses voltage open - loop control to output voltage vectors with different voltage angles, and at this time, the d - q axis current angle is consistent with the voltage angle.

[0067] The host computer reads the duty cycle in the SVPWM output register, and the oscilloscope and the test device read the signals of the upper and lower bridge arms of the three - phase of the logic board and the magnitude and direction of the current in each phase of the three - phase line.

[0068] The host computer is also used to judge the initial state of the permanent - magnet synchronous motor drive system according to the duty cycle in the SVPWM output register, the signals of the upper and lower bridge arms of the three - phase of the logic board, the magnitude and direction of the current in each phase of the three - phase line, the value sampled by the current sensor AD in the motor controller, the current value calculated by the motor controller, the resolver sampling value, and the corresponding angle.

[0069] In some alternative embodiments, the host computer is configured to determine whether the duty ratio values in the SVPWM output register and the voltage vectors of the upper and lower bridge arm signals of the three phases of the logic board correspond to the input voltage angle; determine whether the magnitude and direction of the current calculated by the motor controller are consistent with the magnitude and direction of the current in each phase of the three-phase line measured by the oscilloscope, and whether the current sampling accuracy meets the relevant requirements; record the resolver sampling values and the corresponding angles; use voltage open-loop control to change the voltage vector of the output voltage angle, and repeat the above operations until the number of collected voltage angles has met the accuracy requirements.

[0070] In some alternative embodiments, after the number of collected voltage angles has met the accuracy requirements, the host computer is further configured to determine whether the change in the resolver output angle corresponds to the input voltage angle, and whether the motor rotation direction corresponds to the resolver output signal; calculate the motor zero position compensation value using each group of voltage angles and the corresponding resolver angles.

[0071] In some alternative embodiments, the signals of the upper and lower bridge arms of the three phases of the logic board are read using the oscilloscope probe and the oscilloscope.

[0072] In some alternative embodiments, the magnitude and direction of the current in each phase of the three-phase line are read using a current clamp and an oscilloscope.

[0073] It should be noted that, according to the needs of implementation, each step / component described in the present application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0074] Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for judging the initial state of a permanent magnet synchronous motor drive system, characterized in that, Including: (1) Fix θ = 0 to make the α-β axis of the permanent magnet synchronous motor coincide with the d-q axis, where θ represents the position signal; (2) Use voltage open-loop control to output voltage vectors with different voltage angles. At this time, the d-q axis current angle is consistent with the voltage angle; (3) Judge the initial state of the permanent magnet synchronous motor drive system according to the duty ratio in the SVPWM output register, the signals of the upper and lower bridge arms of the three phases of the logic board, the magnitude and direction of the current in each phase of the three-phase line, the values sampled by the current sensor AD in the motor controller and the current value calculated by the motor controller, the resolver sampling value and the corresponding angle; (3) includes: (3.1) Judge whether the duty ratio value in the SVPWM output register and the signals of the upper and lower bridge arms of the three phases of the logic board correspond to the voltage vector of the input voltage angle; (3.2) Judge whether the magnitude and direction of the current calculated by the motor controller are consistent with the magnitude and direction of the current in each phase of the three-phase line measured by the oscilloscope, and whether the current sampling accuracy meets the relevant requirements; (3.3) Record the resolver sampling value and the corresponding angle; (3.4) Use voltage open-loop control to change the voltage vector of the output voltage angle, and repeat steps (3.1) to (3.3) until the number of collected voltage angles meets the accuracy requirements.

2. The method according to claim 1, characterized in that, After the number of collected voltage angles meets the accuracy requirements, the method further includes: Judge whether the change of the resolver output angle corresponds to the input voltage angle, and whether the motor rotation direction corresponds to the resolver output signal; Calculate the motor zero position compensation value using each group of voltage angles and the corresponding resolver angles.

3. The method according to claim 1 or 2, characterized in that, Use the oscilloscope probe and the oscilloscope to read the signals of the upper and lower bridge arms of the three phases of the logic board.

4. The method according to claim 1 or 2, characterized in that, Use the current clamp and the oscilloscope to read the magnitude and direction of the current in each phase of the three-phase line.

5. A permanent magnet synchronous motor drive system initial state judgment system, characterized in that Including: PMSM motor, motor controller, upper computer, oscilloscope and test device; The motor controller is used to fix θ = 0 of the PMSM motor to make the α-β axis of the permanent magnet synchronous motor coincide with the d-q axis, where θ represents the position signal; use voltage open-loop control to output voltage vectors with different voltage angles. At this time, the d-q axis current angle is consistent with the voltage angle; Read the duty ratio in the SVPWM output register through the upper computer, and read the signals of the upper and lower bridge arms of the three phases of the logic board and the magnitude and direction of the current in each phase of the three-phase line through the oscilloscope and the test device; The upper computer is also used to judge the initial state of the permanent magnet synchronous motor drive system according to the duty ratio in the SVPWM output register, the signals of the upper and lower bridge arms of the three phases of the logic board, the magnitude and direction of the current in each phase of the three-phase line, the values sampled by the current sensor AD in the motor controller and the current value calculated by the motor controller, the resolver sampling value and the corresponding angle; The host computer is used to determine whether the duty ratio value in the SVPWM output register and the voltage vectors of the upper and lower bridge arm signals of the three phases of the logic board correspond to the input voltage angle; determine whether the magnitude and direction of the current calculated by the motor controller are consistent with the magnitude and direction of the current in each phase of the three-phase line measured by the oscilloscope, and whether the current sampling accuracy meets the relevant requirements; record the resolver sampling value and the corresponding angle; use voltage open-loop control to change the voltage vector of the output voltage angle, and repeat the above operations until the number of collected voltage angles meets the accuracy requirements.

6. The system according to claim 5, wherein After the number of collected voltage angles meets the accuracy requirements, the host computer is further used to determine whether the change in the resolver output angle corresponds to the input voltage angle, and whether the motor rotation direction corresponds to the resolver output signal; calculate the motor zero position compensation value using each group of voltage angles and the corresponding resolver angles.

7. The system according to claim 5 or 6, characterized in that, Use the oscilloscope probe and the oscilloscope to read the signals of the upper and lower bridge arms of the three phases of the logic board.

8. The system according to claim 5 or 6, characterized in that, Use the current clamp and the oscilloscope to read the magnitude and direction of the current in each phase of the three-phase line.

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