Rotor observation method and apparatus for permanent magnet synchronous motor, and motor and storage medium
By combining the output results of low-speed and high-speed observers at different speed stages of the permanent magnet synchronous motor for synthetic regulation, the problem of motor torque fluctuation caused by observer switching delay is solved, and more stable motor control is achieved.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- GD MIDEA AIR CONDITIONING EQUIP CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-06-18
Smart Images
Figure CN2025114629_18062026_PF_FP_ABST
Abstract
Description
Rotor observation methods, devices, motors, and storage media for permanent magnet synchronous motors
[0001] Cross-references to related applications
[0002] This application claims priority to Chinese Patent Application No. 202411845469.5, filed on December 13, 2024, entitled "Rotor observation method, apparatus, motor and storage medium for permanent magnet synchronous motor", the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the technical field of permanent magnet synchronous motor control, and in particular to a rotor observation method, device, motor and storage medium for a permanent magnet synchronous motor. Background Technology
[0004] Permanent magnet synchronous motors, used as compressors in outdoor air conditioning units, mostly employ sensorless control methods due to limitations in installation space and cost.
[0005] Sensorless control algorithms are generally divided into model-based methods for medium and high speeds and signal injection methods for low speeds. Model-based methods for medium and high speeds and signal injection methods for low speeds can be designed with corresponding high-speed observers and low-speed observers to observe the motor rotor for control, and to switch between different observers at different stages of the motor's full speed range.
[0006] However, due to the rapid changes in the motor's operating state, there is often a switching delay during the switching of observers, which leads to fluctuations in motor torque and affects the stability and control accuracy of the motor. Summary of the Invention
[0007] The purpose of this application is to at least solve one of the technical problems existing in the prior art, and to provide a rotor observation method, device, motor and storage medium for a permanent magnet synchronous motor, aiming to improve the stability of the observer switching process.
[0008] In a first aspect, embodiments of this application provide a rotor observation method for a permanent magnet synchronous motor, comprising:
[0009] When the motor speed is less than the first preset speed, a low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer.
[0010] When the motor speed increases to a level greater than the first preset speed but less than the second preset speed, both a low-speed observer and a high-speed observer are used to monitor the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the low-speed observer; the second preset speed is greater than the first preset speed; and
[0011] When the motor speed increases to a level greater than the second preset speed, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result.
[0012] The technical solution according to the embodiments of this application has at least the following beneficial effects: The motor's speed range during operation is typically large, requiring different observers at different stages to ensure the accuracy of speed observation. Therefore, when the motor speed is less than a second preset speed, closed-loop adjustment of the motor speed can be performed based on the output of the low-speed observer. When the motor speed increases to above the second preset speed, the accuracy of the low-speed observer decreases, necessitating switching observers and combining the outputs of the low-speed and high-speed observers to obtain a more accurate output. However, the high-speed observer typically requires a period of operation to reach a stable state. When the motor speed increases to above the second preset speed, directly activating the high-speed observer at this time... The accuracy of the high-speed observer is unstable, and consequently, the composite result obtained from the outputs of the low-speed observer and the high-speed observer is also unstable. Therefore, before the motor speed increases to a level greater than the second preset speed, that is, when the motor speed increases to a level greater than the first preset speed but less than the second preset speed, the high-speed observer is activated in advance to observe the motor rotor. This allows the high-speed observer to run for a period of time in advance without using its output. In this way, when the motor speed increases to a level greater than the second preset speed, since the high-speed observer has already run for a period of time and entered a stable state, the composite result obtained from the outputs of the low-speed observer and the high-speed observer is relatively stable, thereby improving the stability of the observer switching process.
[0013] According to some embodiments of this application, a synthesized result is obtained based on the output of a low-speed observer and the output of a high-speed observer, including:
[0014] The difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer is used to compensate for the angular velocity output by the low-speed observer, thus obtaining the composite observed angular velocity.
[0015] According to some embodiments of this application, the synthesized observed angular velocity is calculated using the following formula:
[0016] Where: ω ob3 Δω is the composite observed angular velocity; Δω is the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer; Δω = ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment the motor speed equals the second preset speed to the current moment, and T is the preset switching duration.
[0017] According to some embodiments of this application, the synthesis result also includes a synthesized angle obtained by integrating the synthesized observed angular velocity.
[0018] According to some embodiments of this application, it also includes:
[0019] When the motor speed increases to a level greater than the third preset speed, a high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer; the third preset speed is greater than the second preset speed.
[0020] According to some embodiments of this application, when the motor speed increases to a level greater than a third preset speed, the low-speed observer is controlled to stop observing.
[0021] The first aspect of this application also provides a rotor observation method for a permanent magnet synchronous motor, including:
[0022] When the motor speed is greater than the fourth preset speed, a high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the high-speed observer.
[0023] When the motor speed drops to a level greater than the third preset speed but less than the fourth preset speed, both a low-speed observer and a high-speed observer are used to monitor the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer; the fourth preset speed is greater than the third preset speed; and
[0024] When the motor speed drops below the third preset speed, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result.
[0025] According to some embodiments of this application, a synthesized result is obtained based on the output of a low-speed observer and the output of a high-speed observer, including:
[0026] The angular velocity output by the high-speed observer is compensated based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer to obtain the composite observed angular velocity.
[0027] According to some embodiments of this application, the synthesized observed angular velocity is calculated using the following formula:
[0028] Where: ω ob3 Δω is the composite observed angular velocity; Δω is the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer; Δω = ωob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment the motor speed equals the third preset speed to the current moment, and T is the preset switching duration.
[0029] According to some embodiments of this application, the synthesis result also includes a synthesized angle obtained by integrating the synthesized observed angular velocity.
[0030] According to some embodiments of this application, it also includes:
[0031] When the motor speed drops below the second preset speed, a low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the low-speed observer; the third preset speed is greater than the second preset speed.
[0032] According to some embodiments of this application, when the motor speed drops below a second preset speed, the high-speed observer is controlled to stop observing.
[0033] Secondly, embodiments of this application provide a rotor observation device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the rotor observation method of the first aspect described above.
[0034] Thirdly, embodiments of this application provide an electric motor including the rotor observation device described in the second aspect above.
[0035] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the rotor observation method as described in the first aspect above.
[0036] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description
[0037] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.
[0038] The present application will be further described below with reference to the accompanying drawings and embodiments;
[0039] Figure 1 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in an embodiment of this application;
[0040] Figure 2 is a schematic diagram of the preset speed point of the switching observer during the motor speed increase stage in one embodiment of this application;
[0041] Figure 3 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application;
[0042] Figure 4 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application;
[0043] Figure 5 is a schematic diagram of the preset speed point of the switching observer during the motor speed decrease phase in one embodiment of this application;
[0044] Figure 6 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application;
[0045] Figure 7 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application;
[0046] Figure 8 is a schematic diagram of a rotor observation device for performing a rotor observation method for a permanent magnet synchronous motor according to an embodiment of this application; and
[0047] Figure 9 is a schematic diagram of a rotor observation device for performing a rotor observation method for a permanent magnet synchronous motor according to another embodiment of this application. Detailed Implementation
[0048] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.
[0049] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0050] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If the terms "first" and "second" are used, they are merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0051] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0052] The various embodiments of the rotor observation method for permanent magnet synchronous motors of this application will be further described below with reference to Figures 1-7.
[0053] As shown in Figure 1, Figure 1 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in an embodiment of this application. The rotor observation method for the permanent magnet synchronous motor may include, but is not limited to, steps S110, S120 and S130.
[0054] Step S110: When the motor speed is less than the first preset speed ω1, a low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer.
[0055] Step S120: When the motor speed increases to a level greater than the first preset speed ω1 and less than the second preset speed ω2, the motor rotor is observed simultaneously using a low-speed observer and a high-speed observer, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer; the second preset speed ω2 is greater than the first preset speed ω1.
[0056] Step S130: When the motor speed increases to a level greater than the second preset speed ω2, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result.
[0057] Those skilled in the art will understand that in the closed-loop speed control system of a permanent magnet synchronous motor, an observer is used to observe the motor rotor to provide estimated information on the motor rotor position and speed. This estimated information is then used to perform closed-loop regulation of the motor speed. Furthermore, a low-speed observer is used to observe the motor rotor when the permanent magnet synchronous motor's speed is low, and a high-speed observer is used to observe the motor rotor when the permanent magnet synchronous motor's speed is high. During the transition from switching from a low-speed observer to a high-speed observer and vice versa, both low-speed and high-speed observers can typically be used simultaneously to observe the motor rotor. By adjusting the weights of the outputs of the low-speed and high-speed observers, the system can gradually switch from using only the low-speed observer to using only the high-speed observer, and vice versa.
[0058] It is understandable that the permanent magnet synchronous motor can be debugged and tested in advance to determine the speed range in which the permanent magnet synchronous motor can operate stably and reliably, thereby determining the speed points for switching the low-speed observer and the high-speed observer.
[0059] For example, static testing can be performed at different speeds (e.g., different percentages from 0 to rated speed) to record parameters such as motor current, voltage, and temperature, and observe whether the current and voltage are within the rated range and whether the temperature is within the motor's allowable operating range. Then, analyze the trend of current and voltage changes with speed to check for abnormal fluctuations, whether the temperature rise is proportional to the increase in speed and load, and check for overheating, etc., thereby determining the speed range in which stable and reliable operation can be achieved using a low-speed observer and a high-speed observer, and determining the speed point from high-speed observer to low-speed observer and from low-speed observer to high-speed observer, as well as the transition range between the two speed points;
[0060] Dynamic testing can also be performed, which involves accelerating the motor to its rated speed from a standstill with different accelerations, and decelerating the motor to a stop from its rated speed with different decelerations. The changes in parameters such as current, voltage, and temperature during acceleration and deceleration are recorded, and the smoothness of the motor's response during acceleration is observed, as well as any abnormal vibrations or noises.
[0061] In another embodiment, a mathematical model of the motor, including electrical, mechanical and thermal models, can be established, and simulation software can be used to run the simulation to observe the motor's response at different speeds. The simulation results can then be analyzed to predict the motor's performance in actual operation.
[0062] In summary, by pre-tuning the permanent magnet synchronous motor, the speed range in which the permanent magnet synchronous motor can operate stably and reliably can be determined. The specific tuning method is not limited here, as long as the speed range in which the permanent magnet synchronous motor can operate stably and reliably can be determined.
[0063] In this embodiment, referring to Figure 2, which is a schematic diagram of switching the preset speed point of the observer during the motor speed increase stage in one embodiment of this application, based on the speed increase stage of the permanent magnet synchronous motor, the speed point at which the permanent magnet synchronous motor switches from the low-speed observer to the high-speed observer can be determined to include the second preset speed ω2. When the motor speed is less than the second preset speed ω2, the permanent magnet synchronous motor can operate stably and reliably using only the low-speed observer. If the motor speed is greater than the second preset speed ω2, it is necessary to use both the low-speed observer and the high-speed observer to observe the motor rotor at the same time.
[0064] Therefore, when the motor speed is greater than the second preset speed ω2, the high-speed observer is directly activated. However, because the initial state of the high-speed observer may be inconsistent with the actual state of the motor closed-loop control system, the parameters of the high-speed observer have low adaptability to the current operating conditions, and the motor closed-loop control system may generate more high-frequency noise when the motor is running at high speed, the high-speed observer may not be stable when it is first activated.
[0065] Therefore, in this embodiment, a preset high-speed observer speed point is set before the speed point at which the low-speed observer switches to the high-speed observer during the speed increase phase, namely the first preset speed ω1. When the motor speed is less than the first preset speed ω1, the low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer. When the motor speed increases to a level greater than the first preset speed ω1 and less than the second preset speed ω2, the high-speed observer is activated, and only the low-speed observer is used to observe the motor rotor. The motor speed is adjusted in a closed loop according to the output of the low-speed observer. In this way, during the speed increase phase, the motor speed is in the range of greater than the first preset speed ω1 and less than the second preset speed ω2. The low-speed observer and the high-speed observer run simultaneously. The output of the low-speed observer is used to adjust the motor speed in a closed loop, while the high-speed observer runs in bypass mode and its output does not enter the motor speed closed-loop control system.
[0066] When the motor speed increases to a level greater than the second preset speed ω2, the motor rotor is observed simultaneously using both a low-speed observer and a high-speed observer. A composite result is obtained based on the outputs of the low-speed and high-speed observers, and the motor speed is then adjusted in a closed loop based on this composite result. It is understood that the methods for combining the outputs of the low-speed and high-speed observers can include various approaches. For example, the output of the high-speed observer can be used to compensate for the output of the low-speed observer in real time, and the compensation amount can be gradually increased. In another embodiment, the weight of the high-speed observer's output can be gradually increased while the weight of the low-speed observer's output can be gradually decreased. Alternatively, the weights of the high-speed and low-speed observers' outputs can be dynamically adjusted, or machine learning algorithms, such as neural networks or support vector machines, can be introduced to learn the optimal method for combining the outputs of the low-speed and high-speed observers.
[0067] It is foreseeable that the output results of the low-speed observer and the high-speed observer are used to perform closed-loop regulation of the motor speed in the motor speed closed-loop control system. Therefore, the motor speed used for comparison with the first preset speed ω1 and the second preset speed ω2 is obtained through the low-speed observer and the high-speed observer. In addition, the input sources of the low-speed observer and the high-speed observer are the same, which are the sampled phase current information of the permanent magnet synchronous motor.
[0068] Those skilled in the art can also foresee that when the motor speed increases to a level greater than the second preset speed ω2, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer. At this time, the permanent magnet synchronous motor is in a transitional state of observer switching. Subsequently, when the motor speed continues to increase, since the permanent magnet synchronous motor has already reached a relatively high speed, the accuracy of the low-speed observer decreases significantly at higher speeds. Therefore, when the motor speed increases to a speed point greater than the second preset speed ω2 and also greater than another speed point greater than the second preset speed ω2, which is the speed point at which the transitional state ends, the low-speed observer will stop observing the motor rotor. In another embodiment, the speed range of the permanent magnet synchronous motor is relatively small. When the motor speed increases to a level greater than the second preset speed ω2 and continues to increase to the rated speed, it will not reach the speed point at which the transitional state ends. Therefore, the low-speed observer will not stop observing the motor rotor.
[0069] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, the step S130 above, which obtains a composite result based on the output results of the low-speed observer and the high-speed observer, may include: compensating for the angular velocity output by the low-speed observer based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer, to obtain the composite observed angular velocity.
[0070] Understandably, low-speed observers are typically designed based on mathematical models of permanent magnet synchronous motors operating at low speeds. As the motor speed increases, the original model may fail to accurately describe the motor's dynamic behavior. For example, nonlinear factors such as inertial effects, friction, and wind resistance at high speeds may become more significant. Furthermore, as the speed increases, the motor's electrical and time constants may change, causing the parameters used in the low-speed observer to become inaccurate, thus affecting the observer's performance. Additionally, the design of the low-speed observer may limit its bandwidth, preventing it from responding quickly to rapidly changing states. Moreover, the nonlinear effects of the motor (such as saturation and cross-coupling) may become more pronounced, and the low-speed observer may not have considered these nonlinear effects. Therefore, the accuracy of the low-speed observer may decrease at high speeds, potentially failing to accurately measure the rotor's position and speed.
[0071] Meanwhile, during the acceleration phase of a permanent magnet synchronous motor, high-frequency disturbances and noise in the motor system have a significant impact on speed estimation. Since the high-speed observer may have considered the dynamic characteristics and nonlinear effects of the motor during high-speed operation, and is usually designed with high bandwidth and low noise sensitivity, the high-speed observer has better suppression of high-frequency interference, dynamic response, and anti-interference capabilities at high frequencies. Therefore, in some cases, when the motor speed increases to a level greater than the second preset speed ω2, the output accuracy of the high-speed observer will be worse than that of the low-speed observer. Therefore, when synthesizing the output results of the low-speed observer and the high-speed observer at the same time, it may be better to use the low-speed observer as the master observer and use the output result of the low-speed observer as the main output result.
[0072] Based on this, in this embodiment, the method of synthesizing the output results of the low-speed observer and the high-speed observer is to use the output results of the high-speed observer to compensate for the output results of the low-speed observer. That is, the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer is used to compensate for the angular velocity output by the low-speed observer to obtain the synthesized observation angular velocity. This allows for closed-loop regulation of the motor speed with higher precision after the motor speed increases to a level greater than the second preset speed ω2.
[0073] It is understandable that the parameters obtained by the observer from observing the motor rotor can include the rotor's angular velocity. The rotor speed can be estimated by using the rotor's angular velocity. Therefore, the composite result obtained from the output results of the low-speed observer and the high-speed observer includes the composite observed angular velocity, and the rotor speed can be estimated by using the composite observed angular velocity.
[0074] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, the composite observed angular velocity obtained by compensating the angular velocity output by the low-speed observer based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer in the above steps is calculated using the following formula:
[0075] Where: ω ob3 Δω is the composite observed angular velocity; Δω is the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer; Δω = ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment when the motor speed equals the second preset speed ω2 to the current moment, and T is the preset switching duration.
[0076] It is understandable that the above formula describes the compensation for the angular velocity output by the low-speed observer based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer, where Δω=ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 Here, ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment the motor speed equals the second preset speed ω2 to the current moment, and T is the preset switching duration. Therefore, in the formula... It can be seen as a compensation value. It can be regarded as the compensation coefficient, and Δω can be regarded as the compensation amount;
[0077] Since t is the time elapsed from the moment the motor speed equals the second preset speed ω2 to the current moment, therefore, the compensation coefficient... The compensation amount Δω gradually increases with the increase of rotational speed. The compensation amount Δω is determined based on the actual output angular velocity of the high-speed observer and the actual output angular velocity of the low-speed observer. The compensation amount Δω may change linearly or nonlinearly, which is mainly determined by the stability of the high-speed observer and the low-speed observer. In addition, it can be understood that the higher the performance and stability of the high-speed observer and the low-speed observer, the smaller the compensation amount Δω, and the smaller the compensation for the output angular velocity of the low-speed observer.
[0078] In this embodiment, the preset switching time T is obtained through pre-tuning, for example, by observing the time it takes to switch from using only the low-speed observer to using only the high-speed observer while the permanent magnet synchronous motor is running smoothly throughout the entire process. The specific tuning method is not limited here, as long as the preset switching time can be determined.
[0079] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, regarding the above step S130, the synthesis result also includes the synthesis angle obtained by integrating the synthesis observed angular velocity.
[0080] It is understood that the observer is used to observe the motor rotor to provide estimated information on the rotor's position and speed. The angular velocity output by the observer can be used to estimate the rotor's rotational speed, while the rotor's position can be obtained through the angle output by the observer. Therefore, in this embodiment, the synthesis result also includes a synthesis angle obtained by integrating the synthesized observed angular velocity. In one embodiment, the synthesis angle obtained by integrating the synthesized observed angular velocity can be obtained by multiplying the microcontroller's carrier frequency period by the output result of the observer corresponding to the current stage to obtain the angle increment. That is, when the motor speed is less than the first preset speed ω1, the angle increment is obtained by multiplying the microcontroller's carrier frequency period by the output result of the low-speed observer; when the motor speed increases to a level greater than the first preset speed ω1 and less than the second preset speed ω2, the angle increment is obtained by multiplying the microcontroller's carrier frequency period by the output result of the low-speed observer; when the motor speed increases to a level greater than the second preset speed ω2, the angle increment is obtained by multiplying the microcontroller's carrier frequency period by the synthesis result; subsequently, the synthesis angle is obtained by adding the current angle increment to the previous angle increments.
[0081] As shown in Figure 3, Figure 3 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application; the rotor observation method for a permanent magnet synchronous motor may also include, but is not limited to, step S140.
[0082] Step S140: When the motor speed increases to a level greater than the third preset speed ω3, the motor rotor is observed using a high-speed observer, and the motor speed is adjusted in a closed loop according to the output of the high-speed observer; the third preset speed ω3 is greater than the second preset speed ω2.
[0083] Referring to Figure 2, it can be understood that when the motor speed increases to a level greater than the second preset speed ω2, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer. At this time, the permanent magnet synchronous motor is in a transitional state of observer switching. Subsequently, when the motor speed continues to increase to a level greater than the third preset speed ω3, since the permanent magnet synchronous motor has already reached a relatively high speed, the accuracy of the low-speed observer decreases significantly at higher speeds. Therefore, when the high-speed observer and the low-speed observer are running simultaneously, the simultaneous observation of the motor rotor by the high-speed observer and the low-speed observer is switched to observation of the motor rotor by only the high-speed observer. The output used for closed-loop regulation of the motor speed is then switched from the composite result of the output results of the low-speed observer and the high-speed observer to the output result of the high-speed observer.
[0084] It is understandable that when the motor speed increases to a level greater than the third preset speed ω3, a high-speed observer is used to observe the motor rotor. When the motor speed increases to a level greater than the second preset speed ω2 but less than the third preset speed ω3, both a low-speed observer and a high-speed observer are used to observe the motor rotor. Therefore, in the range where the motor speed is greater than the second preset speed ω2 and less than the third preset speed ω3, the motor is in a switching transition state, and the range where the motor speed is greater than the second preset speed ω2 and less than the third preset speed ω3 is the transition range.
[0085] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, regarding the above step S140, when the motor speed increases to a level greater than the third preset speed ω3, the low-speed observer is controlled to stop observing.
[0086] Understandably, when the motor speed continues to increase to a level greater than the third preset speed ω3, since the permanent magnet synchronous motor has already reached a relatively high speed, the accuracy of the low-speed observer decreases significantly at higher speeds. Furthermore, since the motor is currently in a speed-up state, the motor speed will continue to increase. Therefore, it is not necessary to use the low-speed observer to observe the motor rotor during the subsequent increase in motor speed. Thus, when the motor speed continues to increase to a level greater than the third preset speed ω3, the low-speed observer is controlled to stop observing.
[0087] As shown in Figure 4, Figure 4 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application; the rotor observation method for a permanent magnet synchronous motor includes, but is not limited to, steps S150, S160 and S170.
[0088] Step S150: When the motor speed is greater than the fourth preset speed ω4, a high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the high-speed observer.
[0089] Step S160: When the motor speed drops to a level greater than the third preset speed ω3 and less than the fourth preset speed ω4, the motor rotor is simultaneously observed using both a low-speed observer and a high-speed observer, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer; the fourth preset speed ω4 is greater than the third preset speed ω3.
[0090] Step S170: When the motor speed drops to less than the third preset speed ω3, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result.
[0091] In this embodiment, referring to Figure 5, which is a schematic diagram of switching the preset speed point of the observer during the motor speed decrease phase in one embodiment of this application, the speed point at which the permanent magnet synchronous motor switches from the high-speed observer to the low-speed observer based on the speed decrease phase of the permanent magnet synchronous motor includes the third preset speed ω3. When the motor speed is greater than the third preset speed ω3, the permanent magnet synchronous motor can operate stably and reliably using only the high-speed observer. If the motor speed is less than the third preset speed ω3, it is necessary to use both the low-speed observer and the high-speed observer to observe the motor rotor at the same time.
[0092] It can be seen that when the motor speed is less than the third preset speed ω3, the low speed observer is directly activated. However, because the initial state of the low speed observer may be inconsistent with the actual state of the motor closed-loop control system, and the parameters of the low speed observer have low adaptability to the current operating conditions, the low speed observer may not be stable when it is first activated.
[0093] Therefore, in this embodiment, a pre-activated low-speed observer speed point is set before the speed point at which the high-speed observer switches to the low-speed observer during the speed reduction phase, namely the fourth preset speed ω4. When the motor speed is greater than the fourth preset speed ω4, the high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the high-speed observer. When the motor speed drops to a level greater than the third preset speed ω3 and less than the fourth preset speed ω4, the low-speed observer is activated, and only the high-speed observer is used to observe the motor rotor. The motor speed is adjusted in a closed loop according to the output of the high-speed observer. In this way, during the speed reduction phase, when the motor speed is in the range of greater than the third preset speed ω3 and less than the fourth preset speed ω4, the low-speed observer and the high-speed observer run simultaneously. The output of the high-speed observer is used to adjust the motor speed in a closed loop, while the low-speed observer runs in bypass mode and its output does not enter the motor speed closed-loop control system.
[0094] When the motor speed drops below the third preset speed ω3, the motor rotor is observed simultaneously using both a low-speed observer and a high-speed observer. A composite result is obtained based on the outputs of the low-speed observer and the high-speed observer, and the motor speed is then adjusted in a closed loop based on the composite result. It is understood that the method of combining the outputs of the low-speed observer and the high-speed observer can include various approaches. For example, the output of the low-speed observer can be used to compensate for the output of the high-speed observer in real time, and the compensation amount can be gradually increased. In another embodiment, the weight of the output of the low-speed observer can be gradually increased and the weight of the output of the high-speed observer can be gradually decreased, or the weights of the outputs of the high-speed observer and the low-speed observer can be dynamically adjusted, or machine learning algorithms, such as neural networks or support vector machines, can be introduced to learn the optimal method for combining the outputs of the low-speed observer and the high-speed observer.
[0095] It is foreseeable that the output results of the low-speed observer and the high-speed observer are used to perform closed-loop regulation of the motor speed in the motor speed closed-loop control system. Therefore, the motor speed used for comparison with the third preset speed ω3 and the fourth preset speed ω4 is obtained through the low-speed observer and the high-speed observer. In addition, the input sources of the low-speed observer and the high-speed observer are the same, which are the sampled phase current information of the permanent magnet synchronous motor.
[0096] Those skilled in the art can also foresee that when the motor speed drops below the third preset speed ω3, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer. At this time, the permanent magnet synchronous motor is in a transitional state of observer switching. Subsequently, when the motor speed continues to drop, since the permanent magnet synchronous motor has already reached a relatively low speed, the accuracy of the high-speed observer drops significantly at lower speeds. Therefore, when the motor speed drops below the third preset speed ω3 and below another speed point below the third preset speed ω3, which is the speed point at which the transitional state ends, in one embodiment, the speed point at which the transitional state ends can be the second preset speed ω2, the high-speed observer will stop observing the motor rotor. In another embodiment, the speed range of the permanent magnet synchronous motor is relatively small. After the motor speed drops below the third preset speed ω3, it continues to drop until it stops, and will not reach the speed point at which the transitional state ends. Therefore, the high-speed observer will not stop observing the motor rotor.
[0097] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, the step S170 above, which obtains a composite result based on the output results of the low-speed observer and the high-speed observer, may include: compensating the angular velocity output by the high-speed observer based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer, to obtain the composite observed angular velocity.
[0098] Understandably, the back electromotive force (EMF) of the motor is smaller at low speeds because it is proportional to the rotational speed. High-speed observers are typically designed to handle larger signal amplitudes, so their performance may degrade when the rotational speed signal is small. Furthermore, due to the smaller amplitude of signals like the back EMF, measurement noise has a more significant impact, and the high-speed observer may lack sufficient signal-to-noise ratio to accurately estimate the motor state. Moreover, changes in motor parameters have a greater impact on the observer at low speeds, and the high-speed observer may not be optimized for these changes, leading to increased estimation errors. Additionally, high-speed observers typically have high bandwidth to quickly track changes in motor state, but at low speeds, where changes are slower, excessive bandwidth can make the observer overly sensitive to noise, causing instability. Furthermore, the filters in high-speed observers may be designed for fast convergence, which is advantageous at high speeds, but at low speeds, the filters may overreact to initial errors and become unstable. Therefore, the accuracy of high-speed observers may decrease at low speeds, potentially failing to accurately measure the rotor position and speed.
[0099] Meanwhile, during the deceleration phase of the permanent magnet synchronous motor, the dynamic changes of the motor are relatively small. The low-speed observer, based on a simplified motor model, may be more effective at low speeds, providing stable state estimates. Furthermore, when the motor is running at low speeds, the dynamic response of the motor system slows down, allowing the low-speed observer to more accurately capture the actual speed changes of the motor. It is also more sensitive to load disturbances at low speeds. Therefore, in some cases, when the motor speed decreases to less than the third preset speed ω3, the output accuracy of the low-speed observer may be worse than that of the high-speed observer. Thus, when synthesizing the output results of both the low-speed and high-speed observers, it may be more effective to use the high-speed observer as the master observer and its output as the primary output result.
[0100] Based on this, in this embodiment, the output results of the low-speed observer and the high-speed observer are synthesized by using the output results of the low-speed observer to compensate for the output results of the high-speed observer. That is, the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer is used to compensate for the angular velocity output by the high-speed observer to obtain the synthesized observation angular velocity. This allows for closed-loop regulation of the motor speed with higher precision when the motor speed decreases to less than the third preset speed ω3.
[0101] It is understandable that the parameters obtained by the observer from observing the motor rotor can include the rotor's angular velocity. The rotor speed can be estimated by using the rotor's angular velocity. Therefore, the composite result obtained from the output results of the low-speed observer and the high-speed observer includes the composite observed angular velocity, and the rotor speed can be estimated by using the composite observed angular velocity.
[0102] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, the composite observed angular velocity obtained by compensating the angular velocity output by the high-speed observer based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer in the above steps is calculated using the following formula:
[0103] Where: ω ob3 Δω is the composite observed angular velocity; Δω is the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer; Δω = ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment when the motor speed equals the third preset speed ω3 to the current moment, and T is the preset switching duration.
[0104] It is understandable that the above formula describes the compensation for the angular velocity output by the high-speed observer based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer, where Δω=ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 Here, ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment the motor speed equals the third preset speed ω3 to the current moment, and T is the preset switching duration. Therefore, in the formula... It can be seen as a compensation value. It can be regarded as the compensation coefficient, and Δω can be regarded as the compensation amount;
[0105] Since t is the time elapsed from the moment the motor speed equals the third preset speed ω3 to the current moment, therefore, the compensation coefficient... The compensation amount Δω gradually increases with the increase of rotational speed. The compensation amount Δω is determined based on the actual output angular velocity of the high-speed observer and the actual output angular velocity of the low-speed observer. The compensation amount Δω may change linearly or nonlinearly, which is mainly determined by the stability of the high-speed observer and the low-speed observer. In addition, it can be understood that the higher the performance and stability of the high-speed observer and the low-speed observer, the smaller the compensation amount Δω, and the smaller the compensation for the output angular velocity of the high-speed observer.
[0106] In this embodiment, the preset switching time T is obtained through pre-tuning, for example, by observing the time it takes to switch from using only the high-speed observer to using only the low-speed observer while the permanent magnet synchronous motor is running smoothly throughout the entire process. The specific tuning method is not limited here, as long as the preset switching time can be determined.
[0107] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, regarding the above step S170, the synthesis result also includes the synthesis angle obtained by integrating the synthesis observed angular velocity.
[0108] It is understandable that the observer is used to observe the motor rotor to provide estimated information on the rotor's position and speed. The angular velocity output by the observer can be used to estimate the rotor's rotational speed, while the rotor's position can be obtained through the angle output by the observer. Therefore, in this embodiment, the synthesis result also includes a synthesis angle obtained by integrating the synthesized observed angular velocity. In one embodiment, the synthesis angle obtained by integrating the synthesized observed angular velocity can be obtained by multiplying the microcontroller's carrier frequency period by the output result of the observer corresponding to the current stage to obtain the angle increment. That is, when the motor speed is greater than the fourth preset speed ω4, the angle increment is obtained by multiplying the microcontroller's carrier frequency period by the output result of the high-speed observer; when the motor speed drops to greater than the third preset speed ω3 and less than the fourth preset speed ω4, the angle increment is obtained by multiplying the microcontroller's carrier frequency period by the output result of the high-speed observer; when the motor speed drops to less than the third preset speed ω3, the angle increment is obtained by multiplying the microcontroller's carrier frequency period by the synthesis result; subsequently, the synthesis angle is obtained by adding the current angle increment to the previous angle increments.
[0109] As shown in Figure 6, Figure 6 is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application; the rotor observation method for a permanent magnet synchronous motor may also include, but is not limited to, step S180.
[0110] Step S180: When the motor speed drops to less than the second preset speed ω2, the motor rotor is observed using a low-speed observer, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer; the third preset speed ω3 is greater than the second preset speed ω2.
[0111] Referring to Figure 5, it can be understood that when the motor speed drops below the third preset speed ω3, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer. At this time, the permanent magnet synchronous motor is in a transitional state of observer switching. Subsequently, when the motor speed continues to drop below the second preset speed ω2, since the permanent magnet synchronous motor has reached a relatively low speed, the accuracy of the high-speed observer decreases significantly at lower speeds. Therefore, when the high-speed observer and the low-speed observer are running simultaneously, the simultaneous observation of the motor rotor by both the high-speed observer and the low-speed observer is switched to observation of the motor rotor by only the low-speed observer. The output used for closed-loop regulation of the motor speed is then switched from the composite result of the output results of the low-speed observer and the high-speed observer to the output result of the low-speed observer.
[0112] It is understandable that when the motor speed drops to less than the second preset speed ω2, a low-speed observer is used to observe the motor rotor. When the motor speed drops to more than the second preset speed ω2 but less than the third preset speed ω3, both the low-speed observer and the high-speed observer are used to observe the motor rotor. Therefore, in the range where the motor speed is greater than the second preset speed but less than the third preset speed ω3, the motor is in a switching transition state, and the range where the motor speed is greater than the second preset speed but less than the third preset speed ω3 is the transition range.
[0113] In another embodiment of the rotor observation method for a permanent magnet synchronous motor provided in this application, regarding the above step S180, when the motor speed drops to less than the second preset speed ω2, the high-speed observer is controlled to stop observing.
[0114] Understandably, when the motor speed continues to drop below the second preset speed ω2, since the permanent magnet synchronous motor has already reached a relatively low speed, the accuracy of the high-speed observer drops significantly at lower speeds. Furthermore, since the motor is currently in a deceleration state, the motor speed will continue to decrease. Therefore, it is not necessary to use the high-speed observer to observe the motor rotor during the subsequent decrease in motor speed. Thus, when the motor speed continues to drop below the second preset speed ω2, the high-speed observer is controlled to stop observing.
[0115] Referring to Figure 7, which is a flowchart of a rotor observation method for a permanent magnet synchronous motor provided in another embodiment of this application; regarding the rotor observation method for a permanent magnet synchronous motor, the motor speed increase stage may include, but is not limited to, steps S110, S120, S130 and S140, and the motor speed decrease stage may include, but is not limited to, steps S150, S160, S170 and S180.
[0116] Understandably, during the motor speed increase phase, when the motor speed is less than the first preset speed ω1, a low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the low-speed observer. When the motor speed increases to a level greater than the first preset speed ω1 but less than the second preset speed ω2, both the low-speed and high-speed observers are used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the low-speed observer. When the motor speed increases to a level greater than the second preset speed ω2 but less than the third preset speed ω3, a composite result is obtained based on the outputs of the low-speed and high-speed observers, and the motor speed is adjusted in a closed loop based on the composite result. When the motor speed increases to a level greater than the third preset speed ω3, a high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer.
[0117] During the motor speed reduction phase, when the motor speed is greater than the fourth preset speed ω4, a high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer. When the motor speed decreases to a level greater than the third preset speed ω3 but less than the fourth preset speed ω4, both a low-speed observer and a high-speed observer are used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer. When the motor speed decreases to a level less than the third preset speed ω3 but greater than the second preset speed ω2, a composite result is obtained based on the outputs of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result. When the motor speed decreases to a level less than the second preset speed ω2, a low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop based on the output of the low-speed observer.
[0118] Based on the rotor observation method of the permanent magnet synchronous motor in the above embodiments, the following presents various embodiments of the rotor observation device, motor and computer-readable storage medium of this application.
[0119] As shown in Figure 8, Figure 8 is a schematic diagram of a rotor observation device for performing a rotor observation method for a permanent magnet synchronous motor according to an embodiment of this application.
[0120] In this embodiment, the rotor observation device for performing the rotor observation method of a permanent magnet synchronous motor includes an observer enable module, a low-speed observer, a high-speed observer, a speed synthesis module, and an integration module, wherein,
[0121] The observer enable module is used to determine whether the low-speed observer and the high-speed observer are enabled, that is, to enable the low-speed observer, enable the high-speed observer, or enable both the low-speed observer and the high-speed observer.
[0122] The low-speed observer and the high-speed observer observe the motor rotor according to the instructions of the observer enable module.
[0123] The speed synthesis module is used to determine the output for closed-loop regulation of the motor speed, and to synthesize the output results of the low-speed observer and the high-speed observer, i.e., using the output result ω of the low-speed observer. ob1 The motor speed is closed-loop regulated, and the output result ω of the high-speed observer is used. ob2 The motor speed is controlled in a closed loop, and the output ω of the low-speed observer is used as the basis for the control. ob1 and the output result ω of the high-speed observer ob2 The synthesis result ω was obtained ob3 And based on the synthesis results, the motor speed is adjusted in a closed loop;
[0124] The integration module is used to integrate the synthesized observed angular velocity output by the velocity synthesis module to obtain the synthesized angle θ. ob .
[0125] As shown in Figure 9, which is a schematic diagram of a rotor observation device for performing a rotor observation method for a permanent magnet synchronous motor according to another embodiment of this application, the rotor observation device 900 implemented in this application includes: a processor 920, a memory 910, and a computer program stored in the memory 910 and executable on the processor 920. In Figure 9, a processor 920 and a memory 910 are used as an example.
[0126] The processor 920 and the memory 910 can be connected via a bus or other means. Figure 9 shows an example of a connection via a bus.
[0127] The memory 910, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, the memory 910 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 910 may optionally include remotely located memories 910 relative to the processor 920, which can be connected to the rotor observation device 900 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.
[0128] Those skilled in the art will understand that the device structure shown in FIG9 does not constitute a limitation on the rotor observation device 900, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.
[0129] In the rotor observation device 900 shown in Figure 9, the processor 920 can be used to call the control program stored in the memory 910, thereby implementing the rotor observation method of the permanent magnet synchronous motor described above. Specifically, the non-transient software program and instructions required to implement the rotor observation method of the permanent magnet synchronous motor in the above embodiment are stored in the memory 910. When executed by the processor 920, the rotor observation method of the permanent magnet synchronous motor in the above embodiment is executed.
[0130] It is worth noting that, since the rotor observation device 900 of the embodiments of this application can execute the rotor observation method of the permanent magnet synchronous motor of any of the above embodiments, the specific implementation and technical effects of the rotor observation device 900 of the embodiments of this application can refer to the specific implementation and technical effects of the rotor observation method of the permanent magnet synchronous motor of any of the above embodiments.
[0131] Furthermore, one embodiment of this application also provides an electric motor that includes the rotor observation device described above.
[0132] It is worth noting that, since the motor in the embodiments of this application includes the rotor observation device of the above embodiments, and the rotor observation device of the above embodiments can execute the rotor observation method of the permanent magnet synchronous motor of any of the above embodiments, the specific implementation method and technical effects of the motor in the embodiments of this application can refer to the specific implementation method and technical effects of the rotor observation method of the permanent magnet synchronous motor of any of the above embodiments.
[0133] Furthermore, one embodiment of this application provides a computer-readable storage medium storing computer-executable instructions for performing the rotor observation method for a permanent magnet synchronous motor described above. Exemplarily, the method steps described in Figures 1, 3-4, and 6-7 above are performed.
[0134] It is worth noting that, since the computer-readable storage medium of the embodiments of this application can execute the rotor observation method of the permanent magnet synchronous motor of any of the above embodiments, the specific implementation and technical effects of the computer-readable storage medium of the embodiments of this application can be referred to the specific implementation and technical effects of the rotor observation method of the permanent magnet synchronous motor of any of the above embodiments.
[0135] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which may include computer storage media or non-transitory media and communication media or transient media. As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc DVD or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.
[0136] In the several embodiments provided in this application, it should be understood that the disclosed systems, instruments, and methods can be implemented in other ways. For example, the instrument embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between instruments or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0137] It should also be understood that the various implementation methods provided in the embodiments of this application can be combined arbitrarily to achieve different technical effects.
[0138] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.
Claims
1. A rotor observation method for a permanent magnet synchronous motor, comprising: When the motor speed is less than the first preset speed, a low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer. When the motor speed increases to a level greater than the first preset speed but less than the second preset speed, the low-speed observer and the high-speed observer are used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer; the second preset speed is greater than the first preset speed. as well as When the motor speed increases to a level greater than the second preset speed, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result.
2. The rotor observation method according to claim 1, wherein, The process of obtaining the synthesized result based on the output of the low-speed observer and the output of the high-speed observer includes: The angular velocity output by the low-speed observer is compensated based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer to obtain the composite observed angular velocity.
3. The rotor observation method according to claim 2, wherein, The synthesized observed angular velocity is calculated using the following formula: Where: ω ob3 The synthesized observation angular velocity is denoted as Δω; Δω is the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer; Δω = ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment when the motor speed equals the second preset speed to the current moment, and T is the preset switching duration.
4. The rotor observation method according to claim 2 or 3, wherein, The composite result also includes the composite angle obtained by integrating the composite observed angular velocity.
5. The rotor observation method according to any one of claims 1 to 4, wherein, Also includes: When the motor speed increases to a level greater than the third preset speed, the high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the high-speed observer; the third preset speed is greater than the second preset speed.
6. The rotor observation method according to claim 5, wherein, When the motor speed increases to a level greater than the third preset speed, the low-speed observer is controlled to stop observing.
7. A rotor observation method for a permanent magnet synchronous motor, comprising: When the motor speed is greater than the fourth preset speed, a high-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the high-speed observer. When the motor speed drops to a level greater than the third preset speed but less than the fourth preset speed, the motor rotor is simultaneously observed using both a low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the output of the high-speed observer; the fourth preset speed is greater than the third preset speed. as well as When the motor speed drops below the third preset speed, a composite result is obtained based on the output results of the low-speed observer and the high-speed observer, and the motor speed is adjusted in a closed loop based on the composite result.
8. The rotor observation method according to claim 7, wherein, The process of obtaining the synthesized result based on the output of the low-speed observer and the output of the high-speed observer includes: The angular velocity output by the high-speed observer is compensated based on the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer to obtain the composite observed angular velocity.
9. The rotor observation method according to claim 8, wherein, The synthesized observed angular velocity is calculated using the following formula: Where: ω ob3 The synthesized observation angular velocity is denoted as Δω; Δω is the difference between the angular velocity output by the high-speed observer and the angular velocity output by the low-speed observer; Δω = ω ob2 -ω ob1 ω ob2 ω is the angular velocity output by the high-speed observer. ob1 ω is the angular velocity output by the low-speed observer, t is the timing duration from the moment when the motor speed equals the third preset speed to the current moment, and T is the preset switching duration.
10. The rotor observation method according to claim 8 or 9, wherein, The composite result also includes the composite angle obtained by integrating the composite observed angular velocity.
11. The rotor observation method according to any one of claims 7 to 10, further comprising: When the motor speed drops below the second preset speed, the low-speed observer is used to observe the motor rotor, and the motor speed is adjusted in a closed loop according to the output of the low-speed observer; the third preset speed is greater than the second preset speed.
12. The rotor observation method according to claim 11, wherein, When the motor speed drops below the second preset speed, the high-speed observer is controlled to stop observing.
13. A rotor observation device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein, The processor executes the program to implement the rotor observation method as described in any one of claims 1 to 12.
14. An electric motor comprising the rotor observation device of claim 13.
15. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to cause a computer to perform the rotor observation method as described in any one of claims 1 to 12.