Structure Of Linear Motor Research Articles

Integrated Sliding Mode Velocity Control of Linear Permanent Magnet Synchronous Motor with Thrust Ripple Compensation

In this paper, a compound sliding mode velocity control scheme with a new exponential reaching law (NERL) with thrust ripple observation strategy is proposed to obtain a high performance velocity loop of the linear permanent magnet synchronous motor (LPMSM) control system. A sliding mode velocity controller based on NERL is firstly discussed to restrain chattering of the conventional exponential reaching law (CERL). Furthermore, the unavoidable thrust ripple caused by the special structure of linear motor will bring about velocity fluctuation and reduced control performance. Thus, a thrust ripple compensation strategy on the basis of extend Kalman filter (EKF) theory is proposed. The estimated thrust ripple will be introduced into the sliding mode velocity controller to optimize the control accuracy and robustness. The effectiveness of the proposal is validated with experimental results.

Optimal systemic combined design and control of an automated wind energy conversion system

In this paper, is presented a design and control toll of electromechanical braking system dedicated to wind energy conversion chain. The braking system makes it possible to apply pressure strength at the level of the rotating shaft near to the propeller of the wind turbine. This pressure force is transformed into a dry friction force via the mechanical part of the braking system consisting of a piece of brake lining and steel of the rotating shaft of the propeller. A program of dimensioning by the analytical method of a permanent magnet linear motor structure is developed. The interactions between this program and the braking system control algorithm are taken into account. The integration of the global model under the Matlab-Simulink simulation environment allows full validation of the presented study.

Equivalent Circuit Analysis of Linear Phase-Shifting Transformer with End Effect

The linear phase-shifting transformers (LPSTs) are a new type of transformers with a structure similar to a linear motor that can be used in multiplex technology. A reasonable equivalent circuit is the premise of control research. Based on one-dimensional electromagnetic field analysis of the LPST, we reference the theory of linear motor and propose an equivalent circuit model of the LPST. The LPSTs, which are a phase-shifting transformers based on linear motor structure, are affected by end effects. The end effects affect the mutual inductance and secondary resistance of the LPST, which is modified by four correction coefficients. This paper calculates the four correction coefficients, inductance, and resistance of the LPST and then proposes a single-phase T-type equivalent circuit model considering end effects. Using the analytical model, the output voltages under the three working conditions are calculated and analyzed, and the accuracy is verified by comparison with results obtained by the finite element method. Finally, the accuracy of the analytical method is further verified by experiments under two working conditions, which indicates that the equivalent model is credible and useful for control research of multi-inverter system based on the LPST.

A tubular linear motor structure suitable for large thrust

A tubular linear motor structure suitable for large thrust

Numerical Analysis of Linear Elevator Structure Using Finite Element Method

In this work, the structure of the linear elevator prototype had been investigated numerically using finite element method. The linear motor structure parameters analyzed using Maxwell ANSYS. The time-stepping method depending on Maxwell equations be applied for analyzing and optimizing the magnetic and force characteristics. While the elevator structure parameters were analyzed using ANSYS workbench based on the principle of virtual work. The frame considered as clamped- clamped beam, and the base of the car considered as thin plate with small deflection. The analysis done with maximum applied load of 360 N at 1.5 safety factor. The results show the distribution of the magnetic lines, the flux density values plus the leakage flux inside the slots. The maximum Von-Mises stress and the deformations of the frame and plate at maximum load are acceptable and present save design. In which the maximum deflection of the thin plate not exceed (thickness/5) at maximum design load.

Design and Application of Linear Phase-shifting Transforme

In power conversion equipment, the Phase-shifting Transforme plays an important role in reducing harmonic pollution and improving the quality of output waveform. Based on the principle and structure of linear motor, a linear phase-shifting transformer is designed in this paper to overcome the disadvantages of the traditional phase-shifting transformer with complicated winding structure and difficult expansion. This paper introduces the basic principle of the linear phase-shifting transformer, deduces the relevant formulae of the electromagnetic design of the linear phase-shifting transformer, carries out the finite element simulation, applies the linear phase-shifting transformer to the multiple stacked inverter system, and proves the effectiveness of the designed linear phase-shifting transformer.

A Novel Endocrine Composite Fuzzy Control Strategy of Electromagnetic Hybrid Suspension

To effectively improve the vehicle suspension dynamic performances, minimizing discomfort of passengers and realize vibration energy recovery, a new kind of electromagnetic hybrid suspension (EMHS) system with parallel structure of linear motor and solenoid valve shock absorber is put forward. The linear motor actuator can work at the active state for active control or energy-regenerative state for energy recovery, the solenoid valve shock absorber work at the semi-active state for damping control. Firstly, for the analysis of the hybrid suspension, a quarter dynamic model of EMHS is established. Meanwhile, the mathematical models of linear motor actuator and solenoid valve shock absorber are founded, respectively. Then, for the better suspension control effect based on fuzzy control strategy, a novel endocrine composite fuzzy control strategy is designed. By learning the biological endocrine hormone regulation mechanism, the endocrine control with long feedback and ultra-short feedback is designed. The control laws of the fuzzy controller and endocrine controller are, respectively, designed. Finally, the simulation analysis of suspension dynamic performances and energy-regenerative characteristics is done, respectively. At the same time, the bench test is carried out based on the rapid control prototype with dSPACE platform. The results show the control effect of endocrine composite fuzzy control is better than that of fuzzy control, which improves the dynamic performances. Moreover, part of vibration energy is recovered.

Sensorless Vector Control of Permanent Magnet Synchronous Linear Motor Based on Self-Adaptive Super-Twisting Sliding Mode Controller

Due to its own structural characteristics, permanent magnet synchronous linear motors (PMSLMs) have unstable motor parameters during operation due to the end effect and the inherent magnetic circuit instability. At the same time, linear motors have the characteristics of reciprocating switching motion and high-speed positioning motion in industrial applications, thus placing high demands on the controller. In order to improve the performance of the PMSLM, this paper firstly studies the linear motor structure, the distribution characteristics of its air gap magnetic field are obtained, and the simulation analysis for the back electromotive force (EMF) of PMSLM of its running process is carried out. Then, a state observer based on the sliding mode state observer (SMO) is built to replace the traditional speed sensor and a super-twisting sliding mode controller is designed. The double-closed loop control of the speed and the use of high-order sliding mode control features effectively reduce the chattering of the system and reduce the impact of the observation error brought by the observer on the system. The adaptive sliding mode control strategy is used to effectively suppress the influence of the boundaryless uncertainty interference on the system and reduce the influence of the observation error brought by the observer on the system. This paper also combines the linear motor experimental platform to further verify the control scheme based on the super-twisting sliding mode non-sensing linear motor. The simulation and experimental results show that SMO has accurate speed and position tracking performance, the system's chattering is significantly reduced, the control precision is excellent, and the introduction of adaptive sliding mode controller enhances the robustness of the system.

Cool down time optimization of the Stirling cooler

The cooling power is one of the most important performances of a Stirling cooler. However, in some special fields, the cool down time is more important. It is a great challenge to improve the cool down time of the Stirling cooler. A new split Stirling linear cryogenic cooler SCI09H was designed in this study. A new structure of linear motor is used in the compressor, and the machine spring is used in the expander. In order to reduce the cool down time, the stainless-steel mesh of regenerator is optimized. The weight of the cooler is 1.1 kg, the cool down time to 80K is 2 minutes at 296K with a 250J thermal mass, the cooling power is 1.1W at 80K, and the input power is 50W.

Power Factor Analysis of the Linear Motor in Mines

This paper introduces the structure of linear motor in mines. Analyze the power relation of power-AC -linear motor – vibrant machine, based on this, count the power factor; and make mechanical analysis to the vibrancy, get the power factor, which should be: in the precondition of without collision for the top and bottom magnet, do best to decrease the

Design of magnet arrays for permanent magnetic linear motor

An iron-less single side permanent magnetic linear motor structure is presented, and two-dimensional analytical formulae for its magnetic field are deduced to design the types of magnetic arrays, the thickness of permanent magnet, and the duty ratio of magnet arrays, etc. With certain design parameters, conventional arrays are used instead of a piecewise Halbach arrays, and the machining and assembling of the motor are greatly simplified. Calculation results coincide with that of ANSYS. The analytical formulae can be used in designing cored linear motors by modifying boundary conditions. A linear motor driven bench with a single degree of freedom is realized, where the travel reaches 27 mm, the mass of the moving parts is 1.4 kg, and the maximum acceleration is 11.5 m/s2.