yi Li

Adaptive back-stepping control for the sectioned permanent magnetic linear synchronous motor in vehicle transportation system

Compared to other kinds of motor used in the vehicle transportation systems, the permanent magnet linear synchronous motor (PMSLM) is favorable for the advantages such as high efficiency, high power density, excellent controllability and without middle mechanical transmission. Dividing the long primary into sections, the sectioned PMLSM does well in energy saving, secularity, reliability and maintenance. In this paper, the sectioned PMLSM used in vehicle transportation system (VTS) is designed, whose winding in the primary is divided into two sections. To eliminate the external disturbance and parameter variation, an adaptive back-stepping controller with parameters estimation for a PMSLM speed control system is proposed and the detailed design procedure is discussed. The speed tracking responses with adaptive backstepping controller and PI controller are compared. The simulation results validate the proposed control method.

Design of Giant Magnetostrictive Actuator for fuel injector

This paper presents a basic research on giant magnetostrictive actuator (GMA) for fuel injector. An injector is a pilot operational valve with position servomechanism, which enables to control injection rate freely with input current into the actuator. Based on the combination of finite element analysis and experiment, a prototype of GMA is successfully made as well as the test platform. The injector is actuated by a GMA which outputs displacement of 38.3 mum within 0.03s. The result shows that the analysis of finite element computation meets well with the experimental research. It has a significant guidance meaning for the design and application of GMA based on giant magnetostrictive material (GMM). And this actuator can be also used for active vibration reduction.

Design of Axial and Radial Flux HTS Permanent Magnet Synchronous Motor's Rotor

Most of superconducting motors use the superconducting coils as the excitation coils which are located in the rotor. But its cool system is complex and the cool temperature is lower than 60 K. A novel axial-radial flux HTS (high temperature superconducting) motor is presented with the liquid nitrogen cool, its armature winding in stator is superconducting coils, the excitation winding in cover is superconducting coils, permanent magnets is located in the rotor. Its cool system is simple, and easy to implement. But the electromagnetic parameters are required to ensure the armature current can flow in the winding with low voltage. Through the prototype test with the copper winding instead of the superconducting winding, a novel rotor structure fit for the HTS motor with superconducting armature winding is presented.

Magnetic Field Distribution Around Superconducting Coils in Ferromagnetic Environment

There are two kinds of high temperature superconducting motor (HTS) according to the angle of the superconductors shape, one with the superconducting bulk and the other with the superconducting tapes. Using the superconducting tapes, HTS motors, whose superconducting magnets are located in the rotor, have been researched by many researchers and institutes. This paper research a novel HTS structure that the superconducting coils are placed in the slots of the stator made of ferromagnetic materials. This paper researches the magnetic field distribution of the superconducting coil in the slots and teeth of the stator. The electromagnetic field distribution under the influence of rotating magnetic field and ferromagnetic material is presented firstly. Then, considering the effect of coupling of AC current that flow in the superconducting coils, the distribution of magnetic field is further analyzed. Finally, in order to reduce the alternating current loss, a ferromagnetic slab is added beside the superconducting coils and the improved magnetic field distribution is researched. The simulation result shows that this method is instrumental in harvesting a decrease of the perpendicular flux density from the 0.34 T to 0.06 T.

Thermal characteristic of double-side tabular permanent magnet linear synchronous motor in different working models

Double-side tabular permanent magnet linear synchronous motors (PMLSM), which is incorporated with high power pulse technology, so as to be high power pulsed-PMLSM (PP-PMLSM), is mainly applied in the aspect of short-term acceleration. Under large current, the motor generates high instantaneous thrust and accelerates the load immediately to the expected velocity. The high winding current density and large loss of the motor brings about the issue of fast temperature rise. Meanwhile, the temperature rise is not only correlated with the loss, but also the motor working modes. According to the principles of heat transfer, this paper establishes the numerical model of the two-dimensional (2D) primary transient temperature field, and the basic assumptions and boundary conditions are then provided. Furthermore, under the electromagnetic analysis of the motor, the inner loss and its distribution are researched and identified, which become the discussing foundation of the motor thermal characteristic as follows, under both periodic and short-term continuous working models. Ultimately, the calculating and experimental results furnish the basis of the design and application of double-side tabular PMLSM.

Analysis of 3D Transient Temperature Field for Permanent Magnet Linear Synchronous Motor with High Thrust Density

Double-side tabular permanent magnet linear synchronous motor (PMLSM) with high thrust density, which is with high current density, produces large loss and quick temperature rise. In this paper the mathematic model of three- dimensional (3D) transient temperature Held for a permanent magnet linear motor with high thrust density is established, and the basic hypothetical conditions and relative boundary conditions of the solved region are presented. The temperature fields of motor in different working systems are calculated. Also the laws of motor transient temperature rise and distribution are analyzed. Calculation and practical measurement results are in satisfactory agreement, both of them provide guidance for the security application of these motors with high current density, and provide the basis for the reasonable design of the cooling system.

Research on Closed-Loop Control of Single-Phase Excited Permanent Magnet Synchronous Generator

Aiming at the characteristic of excited single-phase brushless synchronous generator, it is analyzed that the single closed-loop excitation regulator has a defect that its output voltage is reducing with increasing load. Using double closed loop speed regulation system of DC motor for reference. Design a new type regulator which has a excitation current inner loop and voltage outer loop, and use PWM method to regulate excitation current. Based on mathematic model and design target of the diesel generator and voltage regulation of generators steady and dynamic state. Current and voltage regulator are designed by typical link which is known by relation of target and parameter. The test result shows that the whole system has advantage that is regulating voltage precision and fast response. The voltage regulator is designed by engineering method, and it meets the requirements after correcting.