Applied Mechanics and Materials Vols. 416-417

Abstract: This paper investigates the vibration which caused by electromagnetic on the stator end-winding of the large dry submersible motor. Firstly, the electromagnetic field which included transition state and steady state is researched by 3-D FEM. Secondly, the electromagnetic force which lead to vibrations of end-winding is calculated by numerical method, it can be obtained that where endured the largest force density along the slant part of end-winding. Finally, the radial displacement and the axial displacement of the slant part which caused by vibrations is studied, the analysis results show that the axial displacement is larger than the amplitude of radial displacement. It indicates that the slant part of end-winding will be more easily damaged at axial direction than radial direction.

Abstract: The fundamental theory and simplified model of moving-magnet 1inear oscillating motor are presented in this paper. Based on the analysis of the equivalent magnetic and electric circuit model, a 2D finite element (FE) model of a linear oscillating motor with two separated stators is established. Through the FE simulation, the effect of the input voltage on the electric-magnetic force and displacement is investigated. The efficiency of the motor is estimated according to the analysis.

Abstract: According to the requirement for variable-frequency power supply when a liner motor runs in a household appliance, a variable frequency speed regulation system of three-phase SPWM is designed based on ATmega48 Micro-controller. The hardware structure, the SPWM technology of software program and V/f control strategy are analyzed. In the end of this paper, experiment waves are illustrated. The results show that the running of the system is simple and convenient; the reliability of the system is excellent.

Abstract: Two-motor drive system is a multi-variable, nonlinear and strongly coupled system. A new synchronous control strategy for two-motor system is proposed based on radial basis function (RBF) neural network inverse with particle swarm optimization. To enhance the system performance, the particle swarm optimization is adopted to optimize the RBF nerve center, an optimized RBF neural network inverse and a two-motor system is connected in series to form composite pseudo-linear system. This two-motor synchronous system can be decoupled into two independent linear subsystems for speed and tension. Then, the decoupled control is implemented by designing a linear closed-loop adjustor. The experimental results verify that the two-motor synchronous system can be decoupled well for speed and tension based on the proposed neural network inverse system. Also, the proposed system can deal with external disturbances with strong robustness.

Abstract: The free piston energy converter (FPEC) is a combination of a combustion engine and a linear electrical machine which develops a new type of power unit for hybrid electric vehicle. The movement component of the FPEC is a multi-input multi-output coupling nonlinear system. As a consequence, an adaptive decoupling control strategy is presented in this paper for controlling the piston motion. Two neural PID controllers in parallel are employed as the decoupling controller, in which PID gains are auto adjusted by supervised Hebbs learning rule. Simulation results show that the utilization of the neural adaptive PID decoupling controller gives rise to stabilize the piston motion.

Abstract: nverter can operate with power grid in parallel and can return the electricity generated by photovoltaic array with high power factor to power grid. The paper analyzes and compares several grid-connected current control methods, determines that the current control mode used in the design is improved SPWM current virtual value tracking control technology. And the paper analyzes and studies the transfer functions of key links of the inverter, and gives the derivation process of transfer functions. The control system uses dual-loop structure of inner current loop and outer voltage loop, and proposes the design methods of voltage loop and current loop PI regulator.

Abstract: A new burn-in test system of motor controller using zero-sequence current control is presented. The new system consists of two motor controllers and a three-phase reactor. The zero-sequence current control ensures that the three-phase current is symmetrical and sinusoidal, so that two motor controller can be tested at the same time. The results of the simulation demonstrates that the zero-sequence current control is able to ensure that the three-phase current is symmetrical and sinusoidal and can meet all the requirements of the burn-in test system of motor controller. The system uses less hardware, has less loss and it is more energy-efficient, more convenient.

Abstract: In past decades, the technique of superconducting magnetic energy storage (SMES) has received substantial attention both by academia and industry with the great improvement of applicable high temperature superconductors and relevant control technologies. A bridge-type inductive energy management system topology is presented for SMES applications by using a concept of digitalization. The inductive power charging, storing and discharging status are modelled, and then digitalized for the advanced control implementation. As a consequence, an inductive energy control method can be realized by the digitalized models to satisfy relative project requirements by high efficiency and control precession. New principles and methodologies provide the theoretical foundation to achieve digital power inductor energy control and superconducting inductive energy storage device operation.

Abstract: This paper has proposed an efficient direct torque control strategy based on space vector modulation (SVM-DTC) for dual three-phase permanent magnet synchronous motor (DTP-PMSM), which is implemented in a synchronous reference frame aligned with the machine stator flux vector. This strategy adopts the space vector modulation technique to compensate for the stator flux error, and then the continuous smooth response of the vector control and the rapid response of direct torque control are both achieved. Simulation studies of a 3KW DTP-PMSM are carried out. Simulation results show the improvement of the torque response, decrease of the torque ripple, the higher steady performance and better flux waveform.

Abstract: This paper analyzes the PID and the Bang-Bang control methods. To compare the performance of these traditional algorithms, the speed control of a brushless DC drive system is implemented in real-time, using these two methods. The parameters in the controller can be adjusted by the hardware and the software to achieve the optimum performance of the closed-loop system. The experiment results proved that these two controllers have their own merit and defect according to the different steady-state performance and dynamic response respectively. It is concluded that the PID and the Bang-Bang controllers could be used in different applications.