e FOC for Loss Minimization of Induction Motor Using SVM

Abstract Field oriented control (FOC) can provide an ability to rapidly and accurately control torque and speed of induction motors (IM). However, at lower than rated loads, which is a condition that many machines experience for significant portion of their service life, the efficiency is greatly reduced. This paper describes the use of supported vector machine (SVM) to optimize the efficiency of IM drive. The approach eliminates the need of accurate math model and large computation complexity in traditional loss model controller (LMC). The new efficiency optimizing controller adjusts a magnetizing current component in vector controlled drives, which ensures a minimum loss to improve efficiency of the drive system especially when driving light load. The performance of the proposed drive is demonstrated through simulation in MATLAB/SIMULINK and compared the same with traditional FOC without LMC. Results show that there is considerable loss reduction and improvement in efficiency under light load condition using the method

Modeling and Analysis of Permanent Magnet Spherical Motors by A Multi-task Gaussian Process Method and Finite Element Method for Output Torque

Permanent magnet spherical motors (PMSMs) operate on the principle of the dc excitation of stator coils and three freedom of motion in the rotor. Each coil generates the torque in a specific direction, collectively they move the rotor to a direction of motion. Modeling and analysis of the output torque are of critical importance for precise position control applications. The control of these motors requires precise output torques by all coils at a specific rotor position, which is difficult to achieve in the three-dimension space. This article is the first to apply the Gaussian process to establish the relationship of the rotor position and the output torque for PMSMs. Traditional methods are difficult to resolve such a complex three-dimensional problem with a reasonable computational accuracy and time. This article utilizes a data-driven method using only input and output data validated by experiments. The multitask Gaussian process is developed to calculate the total torque produced by multiple coils at the full operational range. The training data and test data are obtained by the finite-element method. The effectiveness of the proposed method is validated and compared with existing data-driven approaches. The results exhibit superior performance of accuracy

Torque and thermal characteristics analysis of a fluid damping based multi-degree-of-freedom motor

This paper presents a novel fluid damping based hybrid drive multi-degrees-of-freedom permanent magnet motor. The structure and working principle of the motor is introduced. The torque features are analyzed using both finite element method and analytical method. Based on the thermal safety and thermal stability in the practical design of this motor, the thermal characteristics with heat sources are calculated and simulated. By using FEA software to model the heating status when the motor works under rated operation and high overload current conditions, the temperature contours within the motor structure can be obtained. The fluid and modal analysis are also conducted with numerical simulation. The research results validate the reasonable structure design of this motor and can be the reference of structure optimization and performance improvement indicators for this kind of motors

Electromagnetic system analysis and improvement of a novel 3-DOF deflection type permanent magnet motor

Ovaj rad predstavlja elektromagnetsku analizu novog motora s permanentnim magnetom na hibridni pogon s više stupnjeva slobode zasnovan na analitičkoj i 3D metodi konačnih elemenata. Prezentirani su i razvijeni proračunski model prostornog magnetskog polja, model analize zakretnog momenta, model uljnog sloja i elektromagnetsko-toplinske spojke. Na temelju simulacijskih rezultata proračuna, nekih važnih značajki karakteristika magnetskog polja i zakretnog momenta, izvedeni su uljni sloj i elektromagnetsko-toplinska spojka i detaljno proanalizirani njihovi učinci s nekim daljnjim mogućnostima poboljšanja oblikovanja. Rezultati pružaju primarni teorijski vodič za dizajn konfiguracije, optimizaciju i istraživanje reguliranja aktuatora deflekcijskog tipa s tri stupnja slobode.This paper presents the electromagnetic analysis of a novel fluid damping based hybrid drive multi-degrees-of-freedom permanent magnet motor based on analytical and 3D finite element methods. The spatial magnetic field calculation model, torque analysis model, oil film model and electromagnetic-thermal coupling are presented and developed. Based on the simulation calculation results, some important features on the magnetic field and torque characteristics, oil film and electromagnetic-thermal coupling are derived and their effects are discussed in detail with some further improvement design possibilities. The results provide the primary theoretical guide for the configuration design, optimization and control research of three degrees of freedom deflection type actuators

Vibration mode analysis of multi-degree-of-freedom permanent magnet synchronous motor

Multi-degree-of-freedom motors have attracted more and more attentions, and the liquid suspension multi-degree-of-freedom PM motor is regarded as one of the research hotspots of new kind of electrical machine. In order to further optimize the structure of liquid suspension permanent magnet synchronous multi-degree-of-freedom motor and improve the stability of the operation, the mode force analysis of the motor's component is carried out. The characteristics and basic structure of the motor are introduced, and the principle and rules of the motor resonance are expounded in detail. Based on the theory of mechanics, the mode of the motor spherical shell is studied and calculated. By finite element analysis, the modal changes of stator shell under static and energized conditions are calculated and the comparison is made. Then, the 2nd order modal deformation of the spherical shell is monitored by hammering and sensor with the measured data obtained and compared with the finite element simulation. The solid mechanical structure of the claw stator core is analyzed so that the stress distribution and deformation displacement distribution are obtained. The results of the simulation and analysis provide the reference for the optimal design of this kind of motors or actuators

Time Delay Estimation Control of Permanent Magnet Spherical Actuator Based on Gradient Compensation

A multi-degree-of-freedom Permanent Magnet Spherical Actuator (PMSpA) has a special mechanical structure and electromagnetic fields, and is easily affected by nonlinear disturbances such as modeling errors and friction. Therefore, the quality of a PMSpA control system may be deteriorated. In order to keep the PMSpA with good trajectory tracking performance, this paper designs a time delay estimation controller based on gradient compensation. Firstly, the dynamic model of the PMSpA with nonlinear terms is derived. The nonlinear terms in the complex dynamic model can be simplified and estimated by the time delay estimation method. Secondly, for the estimation errors caused by time delay control, a gradient compensator is introduced to further correct and compensate for it. Furthermore, the stability of the designed controller is proved by the Lyapunov equation. Finally, the correctness and effectiveness of the controller are validated by comparison with other controllers through simulation. In addition, experimental results have also shown that the control accuracy of the spherical motor can be effectively improved using the proposed controller

Design and Analysis of Electromagnetic-Piezoelectric Hybrid Driven Three-Degree-of-Freedom Motor

Multi-DOF movement actuators are widely used in industry, mainly in the fields of bionics and precision machining. With the non-stop improvement of modern-day industry, the requirements for the precision, integration and flexibility of multi-degree-of-freedom motion actuators in the industrial field have progressively increased. This paper presents a novel electromagnetic–piezoelectric hybrid driven three-degree-of-freedom motor. The driving method of the hybrid drive motor can be divided into electromagnetic driving and piezoelectric driving. The motor structure and working principle are analyzed. The structural parameters are obtained by modal analysis of the stators and rotor. The rationality of the stator structure is proved by using the transient analysis of the piezoelectric stators. The magnetic field characteristics of the motor are analyzed by both analytical method and the finite element method. The contact pressure and displacement between the piezoelectric stator and the rotor are analyzed by the analytical method. A motor drive model is established, which provides the basis for motor optimization design and control. Finally, a motor prototype and its test platform were built, and the experimental results are presented to verify the rationality of the motor design