Control method and system of permanent magnet synchronous motor, and electronic device

Abstract

The application relates to the field of motor control, and provides a control method and system of a permanent magnet synchronous motor and electronic equipment, the method comprising the following steps: applying a super-spiral sliding mode observer to estimate the current of a target permanent magnet synchronous motor and determining a current error; determining a sliding mode surface and a change rate of the sliding mode surface based on the current error; determining a gain adjustment amount based on the sliding mode surface and the change rate of the sliding mode surface; determining a super-spiral sliding mode control law based on the gain adjustment amount; and controlling the target permanent magnet synchronous motor based on the super-spiral sliding mode control law. The application solves the inherent chattering problem of a traditional control method, limits the application of the traditional control method in a precision control occasion, and significantly improves the quietness, reliability and control precision of an underwater propelling motor system while guaranteeing the robustness and dynamic response of the system.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a control method and system for a permanent magnet synchronous motor, as well as electronic equipment. Background Technology

[0002] As a crucial tool for marine resource exploration and development, underwater robots need to adapt to complex marine environments and possess sustained and efficient endurance, which places higher demands on electric propulsion systems. Torque pulsation during motor operation is the primary cause of vibration and noise in underwater thrusters, and this pulsation is directly related to the motor's control precision. Improving control precision can effectively reduce torque pulsation and noise, while also reducing motor losses and temperature rise, improving efficiency and reliability, enhancing propulsion smoothness, and thus increasing the overall system reliability and lifespan. Current research on the control of permanent magnet synchronous motors mainly focuses on traditional control methods such as vector control and direct torque control. However, traditional control methods often suffer from the following problems: 1. Severe chattering: Traditional sliding mode control uses discontinuous switching functions, which causes the system to generate high-frequency chattering near the sliding surface. This not only increases motor losses and noise, but also limits its application in low-noise scenarios.

[0003] 2. Difficulty in coordinating control gain: To ensure system robustness, a higher control gain is often required. However, a fixed gain is prone to saturation of the control quantity under high disturbance conditions, while it leads to gain redundancy under low disturbance conditions, affecting the stability of the system response.

[0004] 3. Limited steady-state accuracy: Due to insufficient coordination between chattering and gain, traditional sliding mode control has significant tracking errors in the steady-state stage, making it difficult to meet the performance requirements of high-precision, low-fluctuation operation scenarios such as underwater propulsion.

[0005] In summary, although traditional sliding mode control methods have strong robustness and fast response characteristics, they have inherent chattering problems, which limit their application in precision control applications. Therefore, there is an urgent need for a control method with better control performance. Summary of the Invention

[0006] This invention provides a control method, system, and electronic equipment for a permanent magnet synchronous motor, which solves the inherent chattering problem of traditional control methods, limiting their application in precision control applications. The solution of this application significantly improves the quietness, reliability, and control accuracy of the underwater propulsion motor system while ensuring system robustness and dynamic response.

[0007] This invention provides a control method for a permanent magnet synchronous motor, comprising: The current of the target permanent magnet synchronous motor is estimated and the current error is determined by using a super-helical sliding mode observer. Based on the current error, the sliding surface and the rate of change of the sliding surface are determined; The gain adjustment amount is determined based on the sliding surface and the rate of change of the sliding surface; Based on the aforementioned gain adjustment, the superspiral sliding mode control law is determined; The target permanent magnet synchronous motor is controlled based on the super-helical sliding mode control law.

[0008] According to the control method for permanent magnet synchronous motors provided by the present invention, the super-helical sliding mode observer conforms to the following formula: (1) in, , The derivative of the state variable estimate. , These are estimates of the state variables. To estimate the error, For symbolic functions, , This is the slid gain coefficient.

[0009] According to the control method for a permanent magnet synchronous motor provided by the present invention, the step of estimating the current of the target permanent magnet synchronous motor and determining the current error using a super-helical sliding mode observer includes: The voltage equation of the target permanent magnet synchronous motor is constructed, and the current of the target permanent magnet synchronous motor is estimated based on the voltage equation to obtain the estimated current; The current of the target permanent magnet synchronous motor is measured to obtain the actual current; The current error is determined based on the estimated current and the actual current.

[0010] According to the control method of the permanent magnet synchronous motor provided by the present invention, the step of determining the sliding surface and the rate of change of the sliding surface based on the current error further includes: The current error is pulled back to the sliding surface by nonlinear damping, and the integral term is smoothed to obtain the back electromotive force estimate. The rotor position and speed of the target permanent magnet synchronous motor are calculated based on the back electromotive force estimate.

[0011] According to the control method for a permanent magnet synchronous motor provided by the present invention, the step of calculating the rotor position and speed of the target permanent magnet synchronous motor based on the back electromotive force estimate includes: The back electromotive force estimate is calculated using the arctangent function to obtain the rotor position and speed of the target permanent magnet synchronous motor.

[0012] According to the control method for a permanent magnet synchronous motor provided by the present invention, determining the gain adjustment amount based on the sliding surface and the rate of change of the sliding surface includes: Using the sliding surface and its rate of change as fuzzy inputs, the gain adjustment amount is obtained according to a preset fuzzy adjustment rule.

[0013] According to the control method of the permanent magnet synchronous motor provided by the present invention, when the sliding surface and the rate of change of the sliding surface are large, the gain adjustment amount is large; When the sliding surface and the rate of change of the sliding surface are small, the gain adjustment amount is small.

[0014] This invention also provides a control system for a permanent magnet synchronous motor and a control method for a permanent magnet synchronous motor, comprising: The current estimation module is used to estimate the current of the target permanent magnet synchronous motor using a super-helical sliding mode observer and determine the current error. The sliding surface determination module is used to determine the sliding surface and the rate of change of the sliding surface based on the current error. The adjustment amount determination module is used to determine the gain adjustment amount based on the sliding surface and the rate of change of the sliding surface; The control law determination module is used to determine the superspiral sliding mode control law based on the gain adjustment amount; The motor control module is used to control the target permanent magnet synchronous motor based on the super-helical sliding mode control law.

[0015] The present invention also provides a permanent magnet synchronous motor, which is controlled using a control method for permanent magnet synchronous motors.

[0016] The present invention also provides an electronic device, including 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 any of the control methods for permanent magnet synchronous motors described above.

[0017] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the control methods for permanent magnet synchronous motors described above.

[0018] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements a control method for any of the permanent magnet synchronous motors described above.

[0019] The control method for permanent magnet synchronous motors provided by this invention can replace traditional mechanical position sensors with a super-helical sliding mode observer, overcoming the problems of photoelectric encoders and other sensors being susceptible to corrosion, having high sealing requirements, and insufficient reliability in underwater environments. While significantly reducing system cost and structural complexity, it enhances the environmental adaptability and long-term operational reliability of the propulsion system under complex working conditions. At the same time, it can adaptively adjust the control gain according to the system's sliding surface and its rate of change, fundamentally suppressing the high-frequency chattering phenomenon inherent in traditional sliding mode control, making the control current and output torque highly smooth, significantly reducing propeller vibration noise, and reducing power device switching losses. Furthermore, based on the gain adjustment, it can achieve fast and accurate current tracking without relying on precise motor parameters and complex online identification, thereby ensuring that the underwater robot can still obtain stable and accurate propulsion power in complex environments such as ocean current disturbances, improving its maneuver control accuracy and operational adaptability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating the control method for a permanent magnet synchronous motor provided in an embodiment of the present invention; Figure 2 This is a block diagram of superspiral sliding mode observation and control provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the three-dimensional change relationship of fuzzy rules provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the control system of the permanent magnet synchronous motor provided in an embodiment of the present invention; Figure 5 This is a graph showing the change in motor speed provided in an embodiment of the present invention; Figure 6 This is a diagram showing the change in motor load provided in an embodiment of the present invention; Figure 7 This is a comparison chart of the actual speed, estimated speed, and target speed using traditional control methods. Figure 8 This is a comparison chart of the actual rotational speed, estimated rotational speed, and target rotational speed of the control method of this application provided in the embodiments of the present invention; Figure 9 This is a schematic diagram of a sudden load change condition provided in an embodiment of the present invention; Figure 10 This is one of the schematic diagrams comparing rotational speed estimation provided in the embodiments of the present invention; Figure 11 This is the second schematic diagram of the rotational speed estimation comparison provided in the embodiment of the present invention; Figure 12 This is a schematic diagram illustrating the speed estimation error of traditional control methods; Figure 13 This is a schematic diagram of the speed estimation error of the control method provided in the embodiment of the present invention; Figure 14 This is a schematic diagram of the three-phase current of a motor using traditional control methods; Figure 15 This is a schematic diagram of the three-phase current of the motor in the control method provided in this embodiment of the invention; Figure 16 This is a schematic diagram of steady-state current time-frequency analysis using a traditional sliding mode observer; Figure 17 This is a schematic diagram of steady-state current time-frequency analysis of the sliding mode observer provided in an embodiment of the present invention; Figure 18 This is a schematic diagram of the dq-axis current time-domain waveform using a traditional control method. Figure 19 This is a schematic diagram of the dq-axis current spectrum waveform of the traditional control method; Figure 20 This is a schematic diagram of the dq-axis current time-domain waveform of the control method provided in the embodiment of the present invention; Figure 21 This is a schematic diagram of the dq-axis current spectrum waveform of the control method provided in the embodiment of the present invention; Figure 22 This is a schematic diagram of the physical structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] Figure 1 This is a flowchart illustrating the control method for a permanent magnet synchronous motor provided in an embodiment of the present invention.

[0024] like Figure 1 As shown, this embodiment provides a control method for a permanent magnet synchronous motor, including: Step 101: Use a super-helical sliding mode observer to estimate the current of the target permanent magnet synchronous motor and determine the current error; In practical applications, the voltage equation of the target permanent magnet synchronous motor can be constructed, and the current of the target permanent magnet synchronous motor can be estimated based on the voltage equation to obtain the estimated current; The current of the target permanent magnet synchronous motor is measured to obtain the actual current; The current error is determined based on the estimated current and the actual current.

[0025] Specifically, the superhelical sliding mode observer conforms to the following formula: (1) in, , The derivative of the state variable estimate. , These are estimates of the state variables. To estimate the error, For symbolic functions, , This is the slid gain coefficient.

[0026] In this embodiment, the superspiral sliding mode employs a second-order sliding surface, designed as a linear combination of system state variables and their derivatives. The choice of the sliding surface function directly affects the dynamic performance and steady-state accuracy of the system. In implementation, the sliding surface coefficients can be rationally designed according to the order and performance requirements of the controlled object to ensure that the system possesses the desired dynamic characteristics on the sliding surface. In a stationary coordinate system, the voltage equation for the target permanent magnet synchronous motor (PMSM) is: = + (2) in, , for and Voltage on the shaft; , where are the inductances along the d-axis and q-axis; , for shaft and The current in the shaft; , To extend the back electromotive force; This refers to the stator winding resistance. It is a differential operator; This represents the electric angular velocity of the motor.

[0027] The core idea of ​​traditional sliding mode control is to force the system trajectory to reach and remain on a preset sliding surface within a finite time using a discontinuous control law. However, superspiral sliding mode, as a representative algorithm of second-order sliding mode, fundamentally changes its core strategy: it no longer directly applies discontinuous signals to the control input, but instead treats them as components of the control input derivative. The dynamic equation of superspiral sliding mode can be expressed as: (3) Among them = , = For the estimated values ​​of the state variables and the estimated values ​​of the state variables, , For the estimated values ​​of the state variables, , For state variables, , This is the sliding diaphragm gain coefficient. , For the disturbance term, It is a symbolic function.

[0028] According to Lyapunov's convergence theorem, when the following parameters satisfy... , And gain , At that time, the system can converge to the sliding surface within a finite amount of time.

[0029] Step 102: Based on the current error, determine the sliding surface and the rate of change of the sliding surface; In practical applications, the sliding surface satisfies the following formula: S= (4) Where S is the sliding surface. , This is an estimated value for the stator current. , This is the actual stator current value. , for shaft and Shaft current estimation error, It is a two-dimensional vector, representing - Sliding surface in a stationary coordinate system.

[0030] Step 103: Determine the gain adjustment amount based on the sliding surface and the rate of change of the sliding surface; In implementation, to address the performance limitations of fixed-gain superspinner control under dynamic disturbances, a fuzzy inference system is introduced to adjust the control gain in real time. This is achieved using a sliding mode surface. and its rate of change As a fuzzy input, the output is the gain adjustment amount. , : (5) Fuzzy rules are formulated based on the following principles: when Increase when larger , To accelerate convergence; when S approaches zero, the gain is appropriately reduced to suppress chattering. This mechanism enables the controller to adapt to different operating conditions, achieving an optimal balance between dynamic response and steady-state accuracy.

[0031] Table 1 below shows the fuzzy logic rule control table provided in this embodiment. As shown in Table 1, the fuzzy inference system is a Mamdain system with two inputs and two outputs. The observed current and the rate of change of current error are selected as inputs, and the sliding gain is selected as the output. The membership functions of the three linguistic variables in fuzzy control all adopt the trimf trigonometric function because the triangle curve has the characteristics of simplicity and low computational workload, and the trimf trigonometric membership function is more sensitive than other membership functions when the input changes slightly.

[0032] Table 1 Fuzzy Logic Rule Control Table

[0033] In the table above, NB indicates that the input variable is in an extremely negative state; NS indicates that the input variable is in a relatively negative state, but less so than NB; Z indicates that the input variable is in a zero state or close to a zero state; PS indicates that the input variable is in a positive state, but to a lesser degree; PB indicates that the input variable is in a highly positive state; PB indicates that the output variable should take a larger positive action; B indicates that the output variable should take a positive action, but to a lesser degree than PB; M indicates that the output variable should take a moderate action; S indicates that the output variable should take a smaller action.

[0034] Figure 3 This is a schematic diagram of the three-dimensional change relationship of fuzzy rules provided in an embodiment of the present invention.

[0035] like Figure 3As shown, this surface plot intuitively illustrates the nonlinear mapping relationship between two input variables and one output variable in a fuzzy control system. It transforms all the qualitative experiences of "if-then" statements in the fuzzy rule base into a global, continuous quantized response surface. Compared to the traditional sliding mode control method that directly controls the output using a "jumping sign function," which inevitably leads to chattering, the control law provided in this application adds a square root term of error plus an integral term, which is equivalent to changing the "hard switch" to a "gradual soft adjustment." The output is continuous and smooth, solving the chattering problem at its root, and can also directly output the back electromotive force estimate.

[0036] Step 104: Determine the superspiral sliding mode control law based on the gain adjustment amount; In practical applications, the designed superspiral sliding mode control law can conform to the following formula: (6) When the system enters the sliding mode When =0, the estimated value of the back electromotive force can be directly obtained from the equivalent control quantity: (7) Step 105: Control the target permanent magnet synchronous motor based on the super-helical sliding mode control law.

[0037] In summary, the control method for permanent magnet synchronous motors provided in this embodiment has the following beneficial effects: 1. Online adaptive optimization of control gain was achieved, enabling the system to achieve the best balance between dynamic response speed and steady-state stability, significantly improving the overall performance of the propulsion system under complex operating conditions. By designing a fuzzy inference engine that takes the sliding surface and its rate of change as input, the scheme in this embodiment can intelligently adjust the gain of the superspiral control law according to the real-time error state of the system (such as "large and rapidly increasing error" or "small and slowing down error"). , When encountering sudden disturbances, the gain is automatically increased for a rapid response and to suppress deviations; when approaching steady state, the gain is automatically decreased to smooth the output and suppress chattering. This enables the propulsion motor to maintain fast, stable, and precise speed tracking, whether under sudden loads, water flow impacts, or constant speed cruising.

[0038] 2. This invention eliminates the low-pass filter required by traditional sliding mode observers, directly outputting continuous and smooth back EMF estimates through a super-spiral observer, fundamentally eliminating phase lag and significantly improving the observation accuracy of rotor position and velocity. This invention applies the super-spiral algorithm to the back EMF observer. Its integral term output is itself a continuous signal, which can be directly used as a high-quality back EMF estimate. , Compared to traditional methods, this approach completely avoids the phase delay and signal distortion caused by low-pass filters, resulting in more accurate and timely position observations. This enables sensorless control systems based on this observer to operate stably and reliably over a wider speed range (especially in the medium-to-high speed range) and effectively reduces noise and vibration in the propulsion system.

[0039] In an exemplary embodiment, the process of determining the sliding surface and its rate of change based on the current error further includes: The current error is pulled back to the sliding surface by nonlinear damping, and the integral term is smoothed to obtain the back electromotive force estimate. The rotor position and speed of the target permanent magnet synchronous motor are calculated based on the back electromotive force estimate.

[0040] Specifically, the current error is input into the superspiral algorithm, and then... Figure 2 As shown, the error is first quickly pulled back by nonlinear damping, then smoothed by integral term and the signal is extracted. The output of integral term is directly a smooth back EMF estimate. Then, the rotor position and speed are calculated using arctangent. The core advantage is that there is no need for low-pass filtering, no phase lag, high accuracy and smooth output.

[0041] The control system of the permanent magnet synchronous motor provided by the present invention will be described below. The control system of the permanent magnet synchronous motor described below can be referred to in correspondence with the control method of the permanent magnet synchronous motor described above.

[0042] Figure 4 This is a schematic diagram of the control system of the permanent magnet synchronous motor provided in an embodiment of the present invention; like Figure 4 As shown, the control system for the permanent magnet synchronous motor provided in this embodiment includes: The current estimation module 401 is used to estimate the current of the target permanent magnet synchronous motor using a super-helical sliding mode observer and determine the current error. The sliding surface determination module 402 is used to determine the sliding surface and the rate of change of the sliding surface based on the current error. The adjustment amount determination module 403 is used to determine the gain adjustment amount based on the sliding surface and the rate of change of the sliding surface; The control law determination module 404 is used to determine the superspiral sliding mode control law based on the gain adjustment amount; The motor control module 405 is used to control the target permanent magnet synchronous motor based on the super-helical sliding mode control law.

[0043] The specific implementation method of the control system for the permanent magnet synchronous motor provided in this embodiment can be implemented with reference to the above embodiment, and will not be repeated here.

[0044] This invention also provides the following method for performance verification of the provided control method for permanent magnet synchronous motor. Specifically, performance verification can be performed in the MATLAB / Simulink simulation environment, and a comparative analysis can be conducted with traditional PI control. The simulation model is built based on a field-oriented control architecture, and the main motor parameters are set as follows: number of pole pairs. ;inductance ;resistance ; magnetic chain .

[0045] To simulate the actual operating conditions of an underwater propulsion system, the simulation was designed with two types of dynamic test scenarios: multi-stage speed step changes and load torque step disturbances, in order to comprehensively evaluate the controller's tracking performance and anti-interference robustness. 1. Speed ​​command sequence: such as Figure 5 As shown, the target speed can be set sequentially from 500 r / min to 1200 r / min to 800 r / min, covering acceleration, high-speed operation and deceleration processes; 2. Sudden change in load torque: such as Figure 6 As shown, two torque step changes can be applied during operation, successively 0Nm→5Nm→3Nm, to simulate the fluid disturbances and load fluctuations experienced by the thruster in a real underwater environment.

[0046] Figure 7 This is a comparison chart of the actual speed, estimated speed, and target speed of the conventional control method provided in the embodiments of the present invention.

[0047] Figure 8 This is a comparison chart of the actual rotational speed, estimated rotational speed, and target rotational speed of the control method provided in this application according to an embodiment of the present invention.

[0048] like Figure 7 and Figure 8 As shown, the traditional sliding mode control method performs poorly in response to speed step commands, exhibiting a lag of approximately 0.02 seconds in the actual speed, followed by an oscillating process with an overshoot of up to 8.3%, a settling time of approximately 0.15 seconds, and a tracking error of approximately 25 r / min even in the steady-state phase. The estimated speed curve output by its observer not only deviates significantly from the actual speed but also exhibits typical chattering characteristics, indicating fundamental limitations of the traditional method in both dynamic tracking and state estimation.

[0049] In contrast, the fuzzy superspiral control provided in this application achieves near-ideal control performance. The system responds to speed commands with almost no delay, exhibits smooth dynamic transitions without overshoot, reduces the settling time to less than 0.02 seconds, and suppresses the steady-state error to below 3 r / min. Particularly noteworthy is the high degree of overlap and perfect smoothness between the estimated and actual speed curves, demonstrating that this observer not only completely eliminates the chattering defects of traditional sliding mode but also provides accurate and reliable state feedback.

[0050] The comparison of these two sets of performance shows that the improvement from traditional sliding mode control to the fuzzy superspiral control provided in this application has increased the system's response speed by more than 30%, improved its steady-state accuracy by 7-9 times, and completely solved the observer chattering problem, achieving a performance leap from "oscillatory convergence" to "overshoot-free precise tracking." This provides a key technical guarantee for achieving fast, smooth, and precise maneuver control of underwater propulsion systems.

[0051] Figure 9 This is a schematic diagram of a load mutation condition provided in an embodiment of the present invention.

[0052] like Figure 9 As shown, at the moment of load change, the rotational speed change curves of the two sliding mode observers under a constant load of 5 Nm show that the traditional sliding mode control method has an overshoot of approximately 40 r / min, while the overshoot is less than 30 r / min. Therefore, under the control strategy provided in this application, the system response is faster and the overshoot is smaller.

[0053] Figure 10 This is one of the schematic diagrams for comparing rotational speed estimation provided in the embodiments of the present invention.

[0054] Figure 11 This is the second schematic diagram of the speed estimation comparison provided in the embodiment of the present invention.

[0055] Figure 12 This is a schematic diagram of the speed estimation error in traditional control methods.

[0056] Figure 13 This is a schematic diagram of the speed estimation error of the control method provided in the embodiment of the present invention.

[0057] like Figures 10 to 13 As shown, a comparative analysis of the observed speed errors of traditional sliding mode and fuzzy superhelical sliding mode clearly reveals a significant deviation in speed estimation in traditional sliding mode, with an error range of approximately ±15 r / min. In contrast, after the motor enters steady-state operation, the error between the observed speed and the actual speed in fuzzy superhelical sliding mode is effectively suppressed to within ±1 r / min, demonstrating its higher accuracy and stability in state observation.

[0058] Figure 14 This is a schematic diagram of the three-phase current of a motor using traditional control methods.

[0059] Figure 15 This is a schematic diagram of the three-phase current of the motor in the control method provided in the embodiment of the present invention.

[0060] like Figure 14 and Figure 15 As shown, under steady-state conditions, the current waveform output by the traditional sliding mode observer is superimposed with significant high-frequency chattering, exhibiting a distorted sine wave with obvious sawtooth spikes, resulting in a significant increase in harmonic content. In contrast, the current waveform output by the fuzzy superspiral sliding mode observer is smooth and continuous, approaching an ideal sine wave, with significantly reduced harmonic components and good three-phase symmetry.

[0061] During dynamic response, traditional sliding mode observers exhibit current waveform distortion when speed or load changes abruptly. This distortion manifests as instantaneous clipping, abrupt phase changes, severe amplitude fluctuations, and high-frequency noise bursts, severely compromising waveform integrity. In contrast, the fuzzy superspiral sliding mode observer maintains the sinusoidal and smooth waveform during the dynamic transition phase. The current amplitude and frequency changes are stable and natural, without abrupt changes or discontinuities, demonstrating superior dynamic adaptability and signal fidelity.

[0062] Figure 16 This is a schematic diagram of steady-state current time-frequency analysis using a traditional sliding mode observer.

[0063] Figure 17 This is a schematic diagram of steady-state current time-frequency analysis of the sliding mode observer provided in an embodiment of the present invention.

[0064] like Figure 16 As shown, the core defect of traditional sliding mode observer control in steady state is clearly revealed: current waveform distortion leads to harmonic pollution as high as 10.42%. In the time domain, the sine wave, which should be smooth, exhibits obvious periodic distortion and high-frequency spikes; in the frequency domain, in addition to the obvious 50Hz fundamental peak, there are also widely distributed low-order harmonics represented by the 3rd, 5th, and 7th harmonics, as well as continuous harmonic groups concentrated in the 800-1000Hz frequency band. This spectral characteristic is the energy manifestation of the "chattering" phenomenon in sliding mode control, which directly leads to increased iron and copper losses in the motor, aggravated torque pulsation, and increased operating noise, seriously affecting system efficiency and the acoustic stealth of underwater propulsion.

[0065] like Figure 17As shown, the control method provided in this embodiment of the invention reduces the current harmonic distortion (THD) rate from 10.42% in the traditional sliding mode to 0.53%, a significant reduction of 94.9%, and reduces the speed observation error from ±15 r / min to ±1 r / min, achieving an order-of-magnitude improvement in current quality and state estimation accuracy. A THD of 10.42% indicates that under the traditional method, nearly 10% of electrical energy is converted into harmful harmonic losses, leading to motor heating, torque pulsation, and noise. A THD of 0.53% achieves top-tier performance, meaning the current is nearly an ideal sine wave, and electrical energy is efficiently converted into useful mechanical torque, directly resulting in improved efficiency, significantly reduced vibration and noise, and a qualitative leap in motor running smoothness. This verifies that this method eliminates chattering at its source.

[0066] Figure 18 This is a schematic diagram of the dq-axis current time-domain waveform using a traditional control method.

[0067] Figure 19 This is a schematic diagram of the dq-axis current spectrum waveform of the traditional control method.

[0068] Figure 20 This is a schematic diagram of the dq-axis current time-domain waveform of the control method provided in the embodiment of the present invention.

[0069] Figure 21 This is a schematic diagram of the dq-axis current spectrum waveform of the control method provided in the embodiment of the present invention.

[0070] like Figures 18 to 21 As shown, traditional control methods have the following drawbacks: Reduced efficiency: Both the invalid current on the d-axis and the high-frequency harmonics on the q-axis will increase the copper and iron losses of the motor.

[0071] Dynamic performance degradation: Current jitter limits the controller bandwidth, causing the system to respond slowly and overshoot more when the load changes or speed tracking occurs.

[0072] System reliability risk: Continuous current oscillations will increase the junction temperature of power devices and shorten the insulation life of IGBTs and motors.

[0073] Conclusion: This set of images clearly exposes the inherent defects of traditional sliding mode control in terms of decoupling performance, steady-state accuracy, and harmonic suppression.

[0074] The control method provided by this invention reduces the dq-axis current harmonic distortion (THD) from 10.42% in traditional sliding mode to almost zero (THD<1%), and suppresses the current fluctuation amplitude from ±1A to within ±0.5A, achieving a harmonic suppression effect of over 50%. This is not an incremental improvement, but a radical solution to the "chattering" problem, providing an ultimate solution for underwater thrusters that is ultra-quiet (smooth current), highly efficient (extremely low loss), and has a high dynamic response.

[0075] Figure 22 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 22 As shown, the electronic device may include: a processor 2210, a communication interface 2220, a memory 2230, and a communication bus 2240, wherein the processor 2210, the communication interface 2220, and the memory 2230 communicate with each other through the communication bus 2240. The processor 2210 can call logic instructions in the memory 2230 to execute a control method for the permanent magnet synchronous motor, the method including: The current of the target permanent magnet synchronous motor is estimated and the current error is determined by using a super-helical sliding mode observer. Based on the current error, the sliding surface and the rate of change of the sliding surface are determined; The gain adjustment amount is determined based on the sliding surface and the rate of change of the sliding surface; Based on the aforementioned gain adjustment, the superspiral sliding mode control law is determined; The target permanent magnet synchronous motor is controlled based on the super-helical sliding mode control law.

[0076] Furthermore, the logical instructions in the aforementioned memory 2230 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0077] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the control method for a permanent magnet synchronous motor provided by the above methods, the method comprising: The current of the target permanent magnet synchronous motor is estimated and the current error is determined by using a super-helical sliding mode observer. Based on the current error, the sliding surface and the rate of change of the sliding surface are determined; The gain adjustment amount is determined based on the sliding surface and the rate of change of the sliding surface; Based on the aforementioned gain adjustment, the superspiral sliding mode control law is determined; The target permanent magnet synchronous motor is controlled based on the super-helical sliding mode control law.

[0078] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the control method for a permanent magnet synchronous motor provided by the methods described above, the method comprising: The current of the target permanent magnet synchronous motor is estimated and the current error is determined by using a super-helical sliding mode observer. Based on the current error, the sliding surface and the rate of change of the sliding surface are determined; The gain adjustment amount is determined based on the sliding surface and the rate of change of the sliding surface; Based on the aforementioned gain adjustment, the superspiral sliding mode control law is determined; The target permanent magnet synchronous motor is controlled based on the super-helical sliding mode control law.

[0079] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0080] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that, include: The current of the target permanent magnet synchronous motor is estimated and the current error is determined by using a super-helical sliding mode observer. Based on the current error, the sliding surface and the rate of change of the sliding surface are determined; The gain adjustment amount is determined based on the sliding surface and the rate of change of the sliding surface; Based on the aforementioned gain adjustment, the superspiral sliding mode control law is determined; The target permanent magnet synchronous motor is controlled based on the super-helical sliding mode control law.

2. The control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The superspiral sliding mode observer conforms to the following formula: （1） in, , The derivative of the state variable estimate. , These are estimates of the state variables. To estimate the error, For symbolic functions, , This is the slid gain coefficient.

3. The control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The application of the super-helical sliding mode observer to estimate the current of the target permanent magnet synchronous motor and determine the current error includes: The voltage equation of the target permanent magnet synchronous motor is constructed, and the current of the target permanent magnet synchronous motor is estimated based on the voltage equation to obtain the estimated current; The current of the target permanent magnet synchronous motor is measured to obtain the actual current; The current error is determined based on the estimated current and the actual current.

4. The control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The process of determining the sliding surface and its rate of change based on the current error further includes: The current error is pulled back to the sliding surface by nonlinear damping, and the integral term is smoothed to obtain the back electromotive force estimate. The rotor position and speed of the target permanent magnet synchronous motor are calculated based on the back electromotive force estimate.

5. The control method for a permanent magnet synchronous motor according to claim 4, characterized in that, The calculation of the rotor position and speed of the target permanent magnet synchronous motor based on the back electromotive force estimate includes: The back electromotive force estimate is calculated using the arctangent function to obtain the rotor position and speed of the target permanent magnet synchronous motor.

6. The control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The step of determining the gain adjustment amount based on the sliding surface and the rate of change of the sliding surface includes: Using the sliding surface and its rate of change as fuzzy inputs, the gain adjustment amount is obtained according to a preset fuzzy adjustment rule.

7. The control method for a permanent magnet synchronous motor according to claim 6, characterized in that, When the sliding surface and the rate of change of the sliding surface are large, the gain adjustment amount is large; When the sliding surface and the rate of change of the sliding surface are small, the gain adjustment amount is small.

8. A control system for a permanent magnet synchronous motor, applied to the control method for the permanent magnet synchronous motor according to any one of claims 1-7, characterized in that, include: The current estimation module is used to estimate the current of the target permanent magnet synchronous motor using a super-helical sliding mode observer and determine the current error. The sliding surface determination module is used to determine the sliding surface and the rate of change of the sliding surface based on the current error. The adjustment amount determination module is used to determine the gain adjustment amount based on the sliding surface and the rate of change of the sliding surface; The control law determination module is used to determine the superspiral sliding mode control law based on the gain adjustment amount; The motor control module is used to control the target permanent magnet synchronous motor based on the super-helical sliding mode control law.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the control method for the permanent magnet synchronous motor as described in any one of claims 1-7.

10. A permanent magnet synchronous motor, characterized in that, The control method of the permanent magnet synchronous motor according to any one of claims 1-7 is used for control.

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