Research On Sensorless Control Strategy Of PMSM Based On Fuzzy Full-order Sliding Mode Observe

Permanent Magnet Synchronous Motor(PMSM)are widely used in civil,industrial,and aerospace electrical drive systems due to their small size,high energy efficiency,and good speed regulation performance.Accurate real-time rotor position information is crucial for precise control of PMSM,but the traditional method of obtaining rotor position through mechanical encoders installed on the motor shaft has several drawbacks,including high cost,increased system volume,and a risk of damage under complex operating conditions.Therefore,research on sensorless control systems for PMSM is of great significance.To address the serious high-frequency vibration problem in rotor position detection when using the traditional sliding mode observer(TSMO)with a fixed sliding mode gain at low speeds of PMSM,a full-order sliding mode observer with fuzzy adaptive regulation sliding mode gain is proposed to improve the anti-vibration performance of the sliding mode over a wide speed range.The high-frequency pulse injection method is used to achieve zero-speed startup and low-speed operation of the motor.A composite control strategy using weighted averaging switching is employed to smoothly switch between the zero-low speed and mid-high speed algorithms,enabling sensorless control of PMSMs over the full speed range.Firstly,this paper proposes a fuzzy control rule based on the full-order sliding mode observer(FSMO),which combines the real-time observed motor speed and uses the error and its change rate between the actual and observed values of stator current as inputs to achieve adaptive sliding mode gain adjustment in different operating states.Continuous sliding mode control with soft switching is realized by using hyperbolic tangent function instead of the traditional signum function.To eliminate the influence of motor speed,the rotor position information is obtained from the back electromotive force using normalized orthogonal lock-in amplifier.Simulation results show that compared with TSMO,this algorithm has advantages in wide-speed range vibration suppression,rotor position estimation accuracy,and anti-interference capability.Secondly,the convex hull effect method is used to achieve zero and low-speed operation of PMSM.The saturation-based convex hull formation mechanism of surface-mounted permanent magnet synchronous motor(SPMSM)is introduced.To address the shortcomings of traditional high-frequency pulse sine voltage injection methods,this paper proposes a high-frequency pulse square wave voltage injection method that can increase the injection voltage frequency.The method of high-frequency and low-frequency signal separation without filters is used to avoid problems such as system bandwidth reduction and response speed decrease caused by filter use.The Lobatto observer is used to extract rotor position,improving rotor position estimation accuracy.Since there is no algorithm that can be applied to both zero-low and mid-high-speed high-performance control,a composite control strategy using weighted averaging switching is employed to achieve smooth switching between the low and mid-high-speed algorithms,thereby achieving sensorless control of PMSM over the full speed range.The effectiveness of the proposed method is verified through simulation.Finally,to verify the practical effectiveness of the algorithm proposed in this article,experimental validation was conducted on a built PMSM semi-physical simulation drive control platform.A series of experiments demonstrated the correctness and practical effectiveness of the sensorless control method used in this article.