Motor inductive field orientation control direct starting method and device and electronic equipment
By using a method of gradually converging estimated speed in a sensorless permanent magnet synchronous motor, a smooth transition between open-loop and closed-loop control is achieved, solving the switching complexity and current surge problems during motor startup and improving startup stability and efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGSHAN BROAD OCEAN
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-10
AI Technical Summary
In the current technology for starting control of permanent magnet synchronous motors without position sensors, the switching process between open-loop control and closed-loop control is complex, prone to current surges and loss of synchronization, and has a long start-up time.
By obtaining the estimated speed of the motor, and using a smooth transition method between open-loop and closed-loop control, the estimated speed is gradually converged to achieve automatic switching between open-loop and closed-loop control, avoiding angle synchronization and speed correction processing. A smooth transition of open-loop ramp speed and excitation current reference value is adopted to ensure the continuity of current and torque.
The switching logic has been simplified, current surges and step loss phenomena have been eliminated, and a smooth transition from open-loop control to closed-loop control has been achieved, improving the stability and efficiency of startup.
Smart Images
Figure CN122371785A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of motor control technology, specifically to a method, apparatus, and electronic device for direct starting of a motor using sensorless magnetic field directional control. Background Technology
[0002] In the field of sensorless permanent magnet synchronous motor starting control, because the back electromotive force of the motor is extremely weak when it is stationary or at low speed, the controller cannot directly obtain the rotor position to achieve closed-loop control. Therefore, existing technologies generally adopt a three-stage current-frequency open-loop control starting scheme. That is, the rotor is first fixed to a known angle through pre-positioning, and then the motor is forced to increase the frequency with a constant current. After the speed increases to the range that the observer can operate, it switches to closed-loop field-oriented control. This scheme requires angle synchronization, current correction, and PI (Proportional-Integral) term initialization during the switch from open-loop to closed-loop, which has problems such as complex switching logic, easy current inrush and step loss, long open-loop drag time, and large starting jitter. Summary of the Invention
[0003] This invention provides a method, device, and electronic device for direct starting of a motor with sensorless magnetic field directional control, which solves the problem in the prior art that it is difficult to achieve a smooth transition from open-loop start-up to closed-loop control of a motor without complex switching and synchronization processing when there is no position sensor.
[0004] In a first aspect, the present invention provides a method for direct starting of a motor using sensorless field-oriented control, the method comprising: Obtain the estimated speed of the motor; When the estimated speed meets the first preset condition, the motor is driven by open-loop speed control, and the estimated speed is continuously updated so that the updated estimated speed gradually converges to the actual speed of the motor. When the updated estimated speed meets the second preset condition, the updated estimated speed is used as the closed-loop control speed to drive the motor.
[0005] This invention provides a sensorless field-oriented direct start method for motors. By continuously updating and gradually converging the estimated speed, it can automatically switch between open-loop and closed-loop control based solely on whether the estimated speed meets preset conditions. The switching process does not require angle synchronization, speed correction, or switching buffering, thus simplifying the switching logic, eliminating current surges and step loss during the switching process, and achieving a smooth transition from open-loop to closed-loop control. This solves the problems of complex switching processes, surges, and step loss in the prior art for sensorless motors from open-loop start to closed-loop control.
[0006] In one alternative implementation, obtaining the estimated speed of the motor includes: Real-time acquisition of motor voltage and current signals; The estimated speed of the motor is calculated based on voltage and current signals.
[0007] In the above technical solution, the acquisition method only needs to collect the voltage and current signals of the motor in real time to calculate the estimated speed. There is no need to install additional physical position sensors, which reduces the system hardware cost and installation complexity.
[0008] In one optional implementation, the first preset condition is: the estimated rotational speed is lower than a set frequency threshold; When the estimated speed meets the first preset condition, the motor is driven by open-loop speed control, including: When the estimated speed is lower than the set frequency threshold, the open-loop ramp speed is used as the open-loop control speed to drive the motor. The open-loop ramp speed is generated linearly based on the preset target speed and ramp time.
[0009] In the above technical solution, by using the estimated speed being lower than the set frequency threshold as the condition for entering open-loop control, and by using open-loop ramp speed to drive the motor, the motor can start with a steadily increasing speed when the estimated speed has not converged, avoiding motor step loss due to sudden speed changes, and ensuring the operational stability during the startup phase.
[0010] In one optional implementation, the second preset condition is: the updated estimated rotational speed reaches or exceeds a set frequency threshold; When the updated estimated speed meets the second preset condition, the updated estimated speed is used as the closed-loop control speed to drive the motor, including: When the updated estimated speed reaches or exceeds the set frequency threshold, the open-loop speed control is stopped, and the updated estimated speed is switched to be used as the closed-loop speed control to drive the motor.
[0011] In the above technical solution, by using the updated estimated speed reaching or exceeding the set frequency threshold as the switching condition, the open-loop control speed is directly stopped and the updated estimated speed is switched to closed-loop drive when the condition is met. The switching process does not require additional angle synchronization or speed correction operations, thereby eliminating switching delay and impact, and realizing a fast and smooth transition from open-loop control to closed-loop control.
[0012] In one alternative implementation, the method further includes: During the operation of the motor driven by open-loop speed control, the actual speed of the motor is obtained; The excitation current reference value is adjusted in real time based on the actual motor speed, so that the excitation current reference value gradually decreases to zero as the actual motor speed increases.
[0013] In the above technical solution, by gradually reducing the reference value of the excitation current to zero as the actual speed of the motor increases during open-loop operation, the sudden removal of the excitation current is avoided, the current surge caused by excitation abrupt change is eliminated, and the excitation is smoothly withdrawn.
[0014] In one alternative implementation, the method further includes: The real-time acquired torque and current reference values are continuously output to the motor as torque and current commands, and the output process of the torque and current reference values remains continuous during the state switching between open-loop control and closed-loop control.
[0015] In the above technical solution, by continuously outputting the torque current reference value to the motor and maintaining continuous output during the switching between open-loop control and closed-loop control, torque interruption or sudden change caused by state switching is avoided, thus ensuring the continuity and stability of motor torque during the switching process.
[0016] In one alternative implementation, the method further includes: During the switch from open-loop control to closed-loop control, the motor phase current remains continuous without jumps, and the rotor angle transitions continuously from the open-loop control angle to the closed-loop control angle.
[0017] In the above technical solution, by maintaining the continuous and non-jumping motor phase current and the rotor angle continuously transitioning from the open-loop control angle to the closed-loop control angle during the switching process, the current surge and angle change at the moment of switching are avoided, the risk of motor step loss is eliminated, and a smooth switching from open-loop control to closed-loop control is achieved.
[0018] In a second aspect, the present invention provides a sensorless magnetic field directional control direct starting device for an electric motor, the device comprising: The estimated speed acquisition module is used to obtain the estimated speed of the motor; The open-loop control module is used to drive the motor to run by using open-loop control when the estimated speed meets the first preset condition, and to continuously update the estimated speed so that the updated estimated speed gradually converges to the actual speed of the motor. The closed-loop control module is used to drive the motor by using the updated estimated speed as the closed-loop control speed when the updated estimated speed meets the second preset condition.
[0019] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the sensorless magnetic field directional control direct start method for motor described in the first aspect or any corresponding embodiment thereof.
[0020] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the sensorless magnetic field directional control direct start method for motors described in the first aspect or any corresponding embodiment thereof.
[0021] Fifthly, the present invention provides a computer program product, including computer instructions, which are used to cause a computer to execute the sensorless magnetic field directional control direct start method for motors described in the first aspect or any corresponding embodiment thereof. Attached Figure Description
[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0023] Figure 1 This is a schematic flowchart of the first method for direct starting of a motor with sensorless magnetic field directional control according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the second process of the sensorless magnetic field directional control direct start method for motors according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the third process of the sensorless magnetic field directional control direct start method for motors according to an embodiment of the present invention; Figure 4 This is a schematic diagram of real-time communication between the excitation current reference value Idref and the torque current reference value Iqref in a 5-stage motor according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the phase current waveform according to an embodiment of the present invention; Figure 6 This is a schematic diagram of real-time communication between the excitation current reference value Idref, the torque current reference value Iqref, and the no-load running angle of the motor in a three-stage motor according to an embodiment of the present invention. Figure 7 This is a structural block diagram of a sensorless magnetic field directional control direct start device for motors according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.
[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0027] According to an embodiment of the present invention, a method for direct starting of a motor with sensorless field-oriented control is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.
[0028] This embodiment provides a sensorless field-oriented direct start method for motors, which can be applied to motor controllers. The motor controller includes an observer. Figure 1 This is a flowchart of a sensorless field-oriented control direct start method for motors according to an embodiment of the present invention, as shown below. Figure 1 As shown, the process includes the following steps: Step S101: Obtain the estimated speed of the motor.
[0029] The motor in this embodiment is compatible with both surface-mounted permanent magnet synchronous motors and built-in permanent magnet synchronous motors.
[0030] The estimated speed of the motor refers to the rotor speed estimate calculated in real time by the motor controller's built-in algorithm based on the motor's voltage and current signals without using physical position sensors.
[0031] Step S102: When the estimated speed meets the first preset condition, the motor is driven by open-loop speed control, and the estimated speed is continuously updated so that the updated estimated speed gradually converges to the actual speed of the motor.
[0032] Among them, open-loop control is a control method that does not rely on the actual feedback signals of the motor (such as rotor position and actual speed). The motor controller directly applies preset command signals (such as voltage, frequency or speed) to the motor to drive the motor to run, without correcting the execution results in real time.
[0033] During the motor startup phase, when the estimated speed calculated by the controller is lower than the set threshold, it is determined that the observer has not yet converged. At this time, the motor is driven by a preset open-loop speed command. Meanwhile, the estimation algorithm in the controller continues to run, using real-time collected voltage and current signals to continuously update the estimated speed, so that the estimated value gradually approaches the real speed as the actual speed of the motor increases, thus preparing accurate speed information for subsequent seamless switching.
[0034] Step S103: When the updated estimated speed meets the second preset condition, the updated estimated speed is used as the closed-loop control speed to drive the motor.
[0035] Closed-loop control is a control method that relies on the actual feedback signal of the motor for real-time correction. The motor controller continuously acquires the actual operating state of the motor (such as speed and position), compares it with the target command, and automatically adjusts the output according to the deviation so that the actual state of the motor accurately follows the command.
[0036] When the continuously updated estimated speed in the background reaches or exceeds the set frequency threshold, it indicates that the observer's estimation result has converged to near the actual speed. At this time, the controller automatically stops outputting the open-loop speed command and instead uses the updated estimated speed as the speed command for closed-loop control to drive the motor. The entire conversion process does not require any angle synchronization or speed correction operations.
[0037] The sensorless field-oriented control direct start method for motors provided in this embodiment continuously updates and gradually converges the estimated speed. It can automatically switch between open-loop control and closed-loop control simply by whether the estimated speed meets preset conditions. The switching process does not require angle synchronization, speed correction, or switching buffer processing, thereby simplifying the switching logic, eliminating current surges and step loss during the switching process, and achieving a smooth transition from open-loop control to closed-loop control. This solves the problems of complex switching process, surges, and step loss in the prior art for sensorless motors from open-loop start to closed-loop control.
[0038] This embodiment provides a sensorless field-oriented control direct start method for motors, which can be used in the aforementioned motor controller, wherein an observer is provided in the motor controller. Figure 2 This is a flowchart of a sensorless field-oriented control direct start method for motors according to an embodiment of the present invention, as shown below. Figure 2 As shown, the process includes the following steps: Step S201: Obtain the estimated speed of the motor.
[0039] Specifically, step S201 includes: Step a: Real-time acquisition of the motor's voltage and current signals; calculation of the estimated motor speed based on the voltage and current signals.
[0040] Specifically, in a sensorless motor controller, the observer, as the core estimation algorithm module, collects the motor's voltage and current signals in real time and dynamically calculates the rotor speed estimate based on the motor's mathematical model. This calculation output is the estimated motor speed. After obtaining this estimated speed, the motor controller uses it as the basis for determining whether the current observer has converged and for subsequent switching decisions between open-loop and closed-loop control.
[0041] In step S202, when the estimated speed meets the first preset condition, the motor is driven to run using open-loop control, and the estimated speed is continuously updated so that the updated estimated speed gradually converges to the actual speed of the motor.
[0042] Specifically, the first preset condition is: the estimated rotational speed is lower than a set frequency threshold, and the above step S202 includes: Step b: When the estimated speed is lower than the set frequency threshold, the open-loop ramp speed is used as the open-loop control speed to drive the motor. The open-loop ramp speed is generated linearly based on the preset target speed and ramp time.
[0043] Specifically, when the motor starts and the estimated speed output by the observer is lower than the set frequency threshold, an open-loop ramp speed signal is used to replace the observer's estimated speed in the open-loop control. Simultaneously, the observer continues to run in the background and continuously updates the estimated speed, causing the estimated speed to gradually converge to the actual motor speed. This achieves the angle of sensorless FOC (Field-Oriented Control). ,in, From the perspective of FOC, For open-loop speed control, The control period or time step is the fixed time interval between two executions of the algorithm by the motor controller, which is in the microsecond or millisecond range.
[0044] It should be noted that the open-loop ramp speed signal is a linearly increasing speed, used to ensure smooth motor startup and prevent loss of synchronization. During the open-loop control phase, the observer uses the voltage equation to estimate the current speed until the estimated speed reaches and exceeds the set frequency threshold. The voltage equation is a mathematical model connecting the motor voltage, current, and speed. The observer uses this equation to estimate the speed inversely based on the measured voltage and current. At low speeds, the speed term in the equation is weak, leading to inaccurate estimations; the estimation results can only be trusted after the speed increases.
[0045] Step S203: During the operation of the motor driven by open-loop speed control, the actual speed of the motor is obtained; the reference value of the excitation current is adjusted in real time based on the actual speed of the motor, so that the reference value of the excitation current gradually decreases to zero as the actual speed of the motor increases.
[0046] Specifically, in the above-mentioned open-loop ramp speed control stage, an excitation current reference value Idref is set. As the actual speed of the motor increases, the current gradually decreases until it returns to zero.
[0047] It should be noted that as the speed increases, the excitation current reference value Idref gradually decreases to 0. A first-order filter can be used to make the excitation current reference value Idref continuously and without impact decay to 0 from the initial value at startup, so as to achieve a smooth transition of Id=0 control for the surface-mounted permanent magnet synchronous motor.
[0048] Step S204: The real-time acquired torque current reference value is continuously output to the motor as a torque current command, and the output process of the torque current reference value remains continuous during the state switching between open-loop control and closed-loop control.
[0049] Specifically, the torque current reference value Iqref is output by the speed loop PI controller throughout the entire process and is not interrupted when switching between open-loop and closed-loop control.
[0050] More specifically, the speed loop PI controller is an adjustment module that calculates and outputs a torque current reference value in real time based on the deviation between the target speed and the actual speed. In this embodiment, the torque current reference value Iqref output by the controller serves as the torque command for the motor throughout the entire process. Whether in the open-loop control stage or the closed-loop control stage, the source is not interrupted or changed due to the switching of control states, thereby ensuring the continuity of motor torque output and the stability of speed regulation.
[0051] Step S205: When the updated estimated speed meets the second preset condition, the updated estimated speed is used as the closed-loop control speed to drive the motor.
[0052] Specifically, the second preset condition is: the updated estimated rotational speed reaches or exceeds a set frequency threshold; the above step S205 includes: Step c: When the updated estimated speed reaches or exceeds the set frequency threshold, stop using open-loop speed control and switch to using the updated estimated speed as the closed-loop speed control to drive the motor.
[0053] When the updated estimated speed output by the observer reaches or exceeds the set frequency threshold, it directly switches to using the updated estimated speed and estimated angle output by the observer to participate in the sensorless FOC closed-loop control, without performing additional angle synchronization, speed correction or switching buffer processing.
[0054] The frequency threshold can be set according to the actual situation. In this embodiment, it is set to 5% of the motor's rated frequency.
[0055] In step S206, during the switch from open-loop control to closed-loop control, the motor phase current is kept continuous without jumps, and the rotor angle is continuously transitioned from the open-loop control angle to the closed-loop control angle.
[0056] During the transition from open-loop control to closed-loop control, the controller maintains continuous torque current command, smoothly exits the excitation current to zero, and directly replaces the open-loop angle with the converged estimated angle. This ensures that the amplitude and phase of the motor phase current do not change abruptly at the moment of switching. At the same time, the rotor angle naturally transitions from the open-loop integral angle to the estimated angle output by the observer, achieving continuous angle connection.
[0057] The sensorless field-oriented control direct start method for motors provided in this embodiment effectively improves upon the shortcomings of Scheme 1, such as switching shock, loss of synchronization, and oscillation, through background estimation, natural catch-up, and no-switching processing. The observer's background convergence ensures natural speed / angle transition. By combining four points—open-loop ramp speed, observer background estimation, first-order Idref filtering descent, and Iqref full-range speed loop PI controller control—the motor starts smoothly and dynamically. The first-order Idref filtering descent allows for smooth demagnetization of Idref, and Iqref is regulated by the speed loop PI controller, creating a closed-loop system that ensures stable motor torque. This embodiment achieves extremely simple and robust no-switching processing logic, eliminating complex switching judgments, synchronization, and corrections, resulting in less code and easier implementation.
[0058] As one or more specific application embodiments of the present invention, combined with Figures 3 to 7 The present invention provides a further detailed description of the sensorless magnetic field directional control direct starting method for motors, such as... Figure 3 As shown, the method includes the following steps: S1. When the motor starts and the estimated speed output by the observer is lower than the set frequency threshold, an open-loop ramp speed signal is used to replace the observer's estimated speed in open-loop control. Simultaneously, the observer continues to run in the background and continuously updates the estimated speed, causing the estimated speed to gradually converge to the actual motor speed. This achieves the angle of sensorless FOC (Field-Oriented Control). .
[0059] S2. In the above open-loop speed control stage, the excitation current reference value Idref is set. As the actual speed of the motor increases, the current gradually decreases until it returns to zero.
[0060] S3, the torque current reference value Iqref is output by the speed loop PI controller throughout the entire process and is not interrupted when switching between open-loop control and closed-loop control.
[0061] S4. When the estimated speed updated by the observer rises to or above the set frequency threshold, the system directly switches to using the updated estimated speed and estimated angle output by the observer to participate in the sensorless FOC closed-loop control, without needing to perform additional angle synchronization, speed correction or switching buffer processing.
[0062] The frequency threshold can be set; in this embodiment, it is set to 5% of the rated frequency.
[0063] The open-loop ramp speed signal is a linearly increasing speed signal, used to ensure smooth motor start-up and prevent step loss.
[0064] During the open-loop speed control phase, the observer uses the voltage equation to estimate the current speed until the estimated speed reaches and exceeds the approved frequency threshold.
[0065] As the speed increases, the excitation current reference value Idref gradually decreases to 0. A first-order filter can be used to make the excitation current reference value Idref continuously and without impact decay to 0 from the initial value at startup, so as to achieve a smooth transition of Id=0 control for surface-mounted permanent magnet synchronous motors.
[0066] Example 1: The motor in this embodiment is a 5-pole motor with a rated frequency of 100 Hz and a frequency threshold set to 5 Hz. The motor is running under no-load. The excitation current reference value Idref and the torque current reference value Iqref are communicated in real time using the virtual oscilloscope software VOFA, as shown below. Figure 4 As shown, from Figure 4It can be seen that the excitation current reference value Idref gradually decreases from a given value, while the torque current reference value Iqref gradually increases from 0. When the observed speed exceeds the frequency threshold, the excitation current reference value Idref becomes 0. Since the torque current reference value Iqref is adjusted according to the speed loop, its value remains essentially unchanged when the speed is constant. Figure 5 The phase current waveform is shown. Figure 5 The horizontal axis represents time, which shows that there is no impact or loss of steps during the process of switching the motor from open-loop control to closed-loop control.
[0067] Figure 4 The horizontal axis represents time, and the vertical axis represents the excitation current reference value Idref and the torque current reference value Iqref.
[0068] Example 2: In this embodiment, the motor is a 3-pole motor with a rated frequency of 100 Hz and a frequency threshold set to 5 Hz. The motor operates under no-load conditions. The excitation current reference value Idref and the torque current reference value Iqref are communicated in real time using the virtual oscilloscope software VOFA. Figure 6 As shown, upon initial power-on, the excitation current reference value Idref is a constant, and the torque current reference value Iqref is 0. As the speed increases, the excitation current reference value Idref gradually decreases to 0. Iqref fluctuates through a speed loop PI controller. Once the speed stabilizes, the torque current reference value Iqref remains essentially constant. To compare with the three-stage start-up, the motor's no-load running angle (angle) is transmitted in real-time using the virtual oscilloscope software VOFA. Furthermore, to examine the relationship between the motor's no-load running angle (angle), the excitation current reference value Idref, and the torque current reference value Iqref during motor operation, they are grouped together. From the perspective of the motor's no-load running angle (angle) and the three-stage I / F start-up, the motor in this embodiment of the invention does not exhibit rotor jitter during positioning angle switching. The method proposed in this embodiment ensures a smooth transition in the motor's no-load running angle, significantly reducing the probability of motor start-up failure.
[0069] Figure 6 The horizontal axis represents time, and the vertical axis represents the excitation current reference value Idref, the torque current reference value Iqref, and the angle of the motor's no-load operation.
[0070] This embodiment also provides a sensorless field-oriented control direct start device for motors, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.
[0071] This embodiment provides a sensorless magnetic field directional control direct start device for motors, such as... Figure 7 As shown, it includes: The estimated speed acquisition module 701 is used to acquire the estimated speed of the motor.
[0072] The open-loop control module 702 is used to drive the motor to run by using open-loop control when the estimated speed meets the first preset condition, and to continuously update the estimated speed so that the updated estimated speed gradually converges to the actual speed of the motor.
[0073] The closed-loop control module 703 is used to drive the motor by using the updated estimated speed as the closed-loop control speed when the updated estimated speed meets the second preset condition.
[0074] In some alternative implementations, the estimated rotational speed acquisition module 701 includes: The speed estimation calculation unit is used to acquire the voltage and current signals of the motor in real time; and calculates the estimated speed of the motor based on the voltage and current signals.
[0075] In some optional implementations, the first preset condition is: the estimated rotational speed is lower than a set frequency threshold; the open-loop control module 702 includes: The open-loop control unit is used to drive the motor by using the open-loop ramp speed as the open-loop control speed when the estimated speed is lower than the set frequency threshold. The open-loop ramp speed is generated linearly based on the preset target speed and ramp time.
[0076] In some optional implementations, the second preset condition is: the updated estimated rotational speed reaches or exceeds a set frequency threshold; the closed-loop control module 703 includes: The open-loop to closed-loop switching unit is used to stop using open-loop speed control and switch to using the updated estimated speed as the closed-loop speed control to drive the motor when the updated estimated speed reaches or exceeds the set frequency threshold.
[0077] In some alternative embodiments, the device further includes: The excitation current reference value adjustment module is used to obtain the actual speed of the motor during the operation of the speed drive motor using open-loop control; and adjust the excitation current reference value in real time based on the actual speed of the motor, so that the excitation current reference value gradually decreases to zero as the actual speed of the motor increases.
[0078] In some alternative embodiments, the device further includes: The torque current reference value continuous output module is used to continuously output the real-time acquired torque current reference value to the motor as a torque current command, and the output process of the torque current reference value remains continuous during the state switching between open-loop control and closed-loop control.
[0079] In some alternative embodiments, the device further includes: The rotor angle control module is used to control the motor phase current to remain continuous without jumps during the process of switching from open-loop control to closed-loop control, and to control the rotor angle to transition continuously from the open-loop control angle to the closed-loop control angle.
[0080] The sensorless field-oriented control direct start device for motors provided in this embodiment of the invention can execute the sensorless field-oriented control direct start method for motors provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.
[0081] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.
[0082] The following is a detailed reference. Figure 8 This diagram illustrates a suitable structural schematic for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 801, which can perform various appropriate actions and processes based on a program stored in read-only memory (ROM) 802 or a program loaded from memory 808 into random access memory (RAM) 803. The RAM 803 also stores various programs and data required for the operation of the electronic device. The processor 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.
[0083] Typically, the following devices can be connected to I / O interface 805: input devices 806 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 807 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 808 including, for example, magnetic tapes, hard disks, etc.; and communication devices 809. Communication device 809 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 8 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.
[0084] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 809, or installed from a memory 808, or installed from a ROM 802. When the computer program is executed by the processor 801, it performs the functions defined in the sensorless field-oriented control direct start method for motors according to embodiments of the present invention.
[0085] Figure 8 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.
[0086] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that the computer, processor, microprocessor controller, or programmable hardware includes storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the sensorless magnetic field-oriented direct start method for motors shown in the above embodiments is implemented.
[0087] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.
[0088] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A method for direct starting of a motor using sensorless magnetic field directional control, characterized in that, The method includes: Obtain the estimated speed of the motor; When the estimated speed meets the first preset condition, the motor is driven by open-loop control, and the estimated speed is continuously updated so that the updated estimated speed gradually converges to the actual speed of the motor. When the updated estimated speed meets the second preset condition, the updated estimated speed is used as the closed-loop control speed to drive the motor.
2. The method according to claim 1, characterized in that, The process of obtaining the estimated speed of the motor includes: Real-time acquisition of motor voltage and current signals; The estimated speed of the motor is calculated based on the voltage and current signals.
3. The method according to claim 1, characterized in that, The first preset condition is: the estimated rotational speed is lower than a set frequency threshold; When the estimated rotational speed meets the first preset condition, the motor is driven by open-loop speed control, including: When the estimated speed is lower than the set frequency threshold, the open-loop ramp speed is used as the open-loop control speed to drive the motor. The open-loop ramp speed is generated linearly based on the preset target speed and ramp time.
4. The method according to claim 3, characterized in that, The second preset condition is: the updated estimated rotational speed reaches or exceeds the set frequency threshold; When the updated estimated speed meets the second preset condition, the updated estimated speed is used as the closed-loop control speed to drive the motor, including: When the updated estimated speed reaches or exceeds the set frequency threshold, the open-loop control speed is stopped, and the updated estimated speed is used as the closed-loop control speed to drive the motor.
5. The method according to claim 1, characterized in that, The method further includes: During the operation of the motor driven by open-loop speed control, the actual speed of the motor is obtained; The excitation current reference value is adjusted in real time based on the actual speed of the motor, so that the excitation current reference value gradually decreases to zero as the actual speed of the motor increases.
6. The method according to claim 1, characterized in that, The method further includes: The real-time acquired torque and current reference values are continuously output to the motor as torque and current commands, and the output process of the torque and current reference values remains continuous during the state switching between open-loop control and closed-loop control.
7. The method according to claim 1, characterized in that, The method further includes: During the switch from open-loop control to closed-loop control, the motor phase current remains continuous without jumps, and the rotor angle transitions continuously from the open-loop control angle to the closed-loop control angle.
8. A sensorless magnetic field directional control direct starting device for an electric motor, characterized in that, The device includes: The estimated speed acquisition module is used to obtain the estimated speed of the motor; An open-loop control module is used to drive the motor to run by using open-loop control speed when the estimated speed meets the first preset condition, and to continuously update the estimated speed so that the updated estimated speed gradually converges to the actual speed of the motor. The closed-loop control module is used to drive the motor by using the updated estimated speed as the closed-loop control speed when the updated estimated speed meets the second preset condition.
9. An electronic device, characterized in that, include: The device includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the sensorless field-oriented control direct start method for motors as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the sensorless magnetic field oriented control direct start method for motors according to any one of claims 1 to 7.