Applied Mechanics and Materials Vols. 416-417

Abstract: The induction motor is one of the most used electric machines in variable speed system in the different field of industry due to its robustness, mechanical strength and low cost. Despite these qualities, the induction machine is subjected during its operation to a number of constraints of various natures (electrical, mechanical and environmental). This paper focuses on the diagnosis and the detection of the short circuit fault between turns in the stator winding of an induction machine, based on analyzing the evolution of the stator current in each stator phase, using tools based both on motor current spectral analysis and Park vector approach. A study by simulation was presented. The obtained results show that the considered methods can effectively diagnose and detect abnormal operating conditions in induction motor applications. Therefore, they clearly show the possibility of extracting signatures and the application of these techniques offered reliable and satisfactory results for the diagnosis and detection of such fault.

Abstract: The extended state observer (ESO) was applied in the sensorless single phase Stirling linear generator drives in this paper. The structure of the linear generator was introduced and mathematical model was built. To detect the mover position in the condition of position sensorless, the back-EMF ESO was deduced to calculate the position. This strategy was realized in the simulation and experiment. Compared with the normal state observer, in the conditions of noise and imprecision of generator parameters, ESO would improve the robustness of the system.

Abstract: The thesis systematically researches electromagnetism and mechanical characteristic of primary segmented permanent magnet linear synchronous motor (PS-PMLSM), and discusses the varying rules of coupling flux linkage and inductance of each stator segment. The paper propose the space vector modulation direct thrust control (SVM-DTC) algorithm that based on thrust and flux observer, but also analyzes and builds adaptive slide mode observer (SMO), which adopts multi-segment estimate back-EMF combined method and phase locked loops (PLL) to estimate the position and speed of mover. Owing to the methods above, they are able to efficiently solve application problems in PS-PMLSM, which can't be settled through the conventional SVM-DTC and sensorless controlling method. Finally, the effectiveness of the algorithms is verified by simulation test.

Abstract: A sensorless position detection technique based on iron core B-H hysteresis for PM brushless DC motors at standstill and low-speed is presented. A signal acquisition setup and a control method are provided. Experiments show that this technique has a good starting and low-speed control performance for both non-salient and salient motors. With this technique, a closed-loop starting can be achieved and the start-up time can be shortened. This technique has a wide adaptability and has good application prospects.

Abstract: In this paper, for the strong electromagnetic interference environment, a kind of 6500V/1000A thyristor controller is designed. The controller includes a main trigger state detection module, an optical fiber communication module, a temperature detection module, a main controller module, and a trigger module. It highlights the thyristor trigger circuit and its corresponding detection circuit, this trigger circuit can provide a strong trigger pulse to ensure a reliable triggering of thyristors at any moment, the detection circuit can improve the reliability of the system.

Abstract: In this paper, a new control strategy is put forward, which is a single neuron PID control based on the quadratic performance index (QPI) learning algorithm. This single neuron PID control is self-learning and self-adjusting. Through the study of system performance, the weights of the neuron are adjusted by the QPI learning algorithm. The new strategy solves the contradiction between fast tracking performance and robustness in the positioning servo system. In addition, the mathematic model of voice coil motor is analyzed. In order to improve the fast response performance and disturbance suppression of the position loop, the Two-Degree-of-Freedom (TDOF) control is proposed. The simulation results show that disturbance rejection and dynamic performance of the VCM servo control system have been improved. Compared with the utilizing traditional PID system, this new control strategy has stronger self-adapting and robustness.

Abstract: In order to eliminate steady-state speed error of PMSM backstepping control system, an integral backstepping speed control algorithm is designed in this paper. By adding speed error integral factor in the speed Lyapunov function, the speed error can finally converge to zero when PMSM operates in steady-state. On this basis, an integral backstepping speed control algorithm based on RBF neural network compensation is proposed for PMSM backstepping control system used for high-altitude electric propulsion system which is vulnerable to load torque variables. The integral backstepping speed controller based on PMSM reference model can ensure global asymptotic convergence of the whole control system. In order to achieve fast robust adaptive control, the RBF neural network is adapted to online compensate dq axis current error produced by the reference speed and load torque changes. Simulink simulation results verify the feasibility of the given algorithm.

Abstract: The paper presents the drive system of the developed Switched Reluctance linear motor in hardware and in software. The structure and photograph of the three-phase 6/4 structure Switched Reluctance linear motor are given. The main circuit topology of power converter is also given. The designed software for TMS320F2812 DSP is described, includes main program, functional subroutine module and interrupt service subroutine module. The Switched Reluctance linear motor drive prototype was tested experimentally. The velocity curves and the phase current waveforms are given.

Abstract: It has been proposed that the traction and levitation of the carrier in the maglev system are controlled by the thrust and attractive force generated in Linear Induction Motor (LIM). In this system, the thrust and attractive force of LIM are controlled simultaneously and independently by the two different frequency components. In this paper, it is proposed to use the frequency component synchronous with the motor speed as one of the frequency components. It makes the design of the controller easier. The controller is designed using the measured parameters of LIM. It is verified that both the traction and levitation control are achieved by the simulation results.

Abstract: This paper takes a three phase Switched Reluctance linear motor as the research object, presents a nonlinear simulation of its drive system based on MATLAB platform. PI and Fuzzy control algorithms are used in the speed control system. The controller parameters adjustment process and the influence of different parameters and algorithms on the dynamic and static performance of the system are introduced.