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A new fault diagnosis method of inter-turn short circuit detection in generator rotor windings based on wavelet transform is presented. The detection method is based on the singularity characteristics of the induced electromotive force signal of search coil in the air gap. Electromagnetism characteristic of turbo-generator rotor windings is analyzed. Wavelet transform was applied to the detection...
To solve the problems with the conventional direct torque control (DTC) of high speed permanent magnet synchronous motors (PMSM), a variable structure sliding mode direct torque control (VSS-DTC) without sensor is proposed in this paper. The control law of high speed PMSM VSS-DTC and the methodology of speed estimation are presented. The simulation model of the sensorless VSS-DTC system is built and...
Based on the analysis of the magnetic field, a new simplified radial force analytical model for switched reluctance motors is established in this paper, in which saturation and fringing flux are considered. Moreover, the radial force is predicted by using FEM, and the model is validated by its predictions against those of the finite element method (FEM). Furthermore, the relationships between the...
A correction factor fuzzy-PID control method is adopted in order to solve the vibration of elevator cab because of the edge effect in the linear elevators driven by the permanent magnet linear synchronous motor (PMLSM). The fuzzy control has the characteristics of being not completely dependent on the mathematics model, but the fuzzy control rules are obtained by experiences of authors or knowledge...
Due to multivariable, highly nonlinear, strong coupling, time-varying dynamics and unavailability of measurements, induction motor control is still a difficult and complex engineering problem. Vector control has replaced traditional control method using the ratio of voltage and frequency as a constant, which improve greatly dynamic control efficiency of motor. However, under the circumstances of changing...
Electromagnetic aircraft launch system (EMALS) use linear motor to accelerate aircraft to launch speed. This paper presents a new method based on fuzzy-neural of HSLIMEO. It is important to improve efficiency not only saving economic and energy, but also reducing environmental pollution. To optimize efficiency, fuzzy controller combined with field-oriented scheme is proposed to work to optimize flux...
In this paper, a method for predicting the electromagnetic vibration of PM brushless motors is presented. It has accounted for both PM blushless AC and DC motors. It calculates the electromagnetic force on individual stator teeth by the Maxwell stress method, based on 2-D finite element analysis of the electromagnetic field. The resulting radial force contour is then used in an analytical mechanical...
The developed switched reluctance starter/generator system in low voltage is presented, which is made up of the three-phase 12/8 structure double salient reluctance machine, three-phase asymmetric bridge single polarity power converter and the controller. The three-phase 12/8 structure double salient reluctance machine, the three-phase asymmetric bridge single polarity power converter and the control...
A novel sensorless control for switched reluctance motor (SRM) driven by the three-phase full-bridge inverter is proposed. The most commonly used drive for SRM is the asymmetric half-bridge inverter but its main disadvantage is the cost due to the number of switches and diodes required to realized the drive, in comparison with the much cheaper and more widely available three-phase full-bridge inverter...
Halbach array as a new type of magnet array had been highly attached importance to since it was proposed. The application domain of PM motor was greatly widened because of excellent performance of Halbach array magnets. The Halbach array PM motor has many merits such as simple structure, light weight and low loss. In this paper, Halbach array magnets are classified and analyzed according to magnet...
In this paper, the sensorless control of the interior permanent magnet synchronous motors using the sliding mode and the binary observers are compared. Also, the structure of the above observers only uses the voltage equation. Since the parameters of the dynamic equation such as machine inertia or viscosity friction coefficient are not well known and these values can be easily changed during normal...
A new sensorless rotor position detecting method for self-controlled synchronous motors is proposed. The proposed method is based on the idea that the induced electromotive forces in the armature windings due to the pulsation included in the field current when a chopper is used as a field circuit depend on the rotor position of the motor. The principle of the proposed method is explained first. Then...
Accurate knowledge of the high frequency inductance profile plays an important role in many designs of sensorless controllers for surface inductance. A special algorithm is used to decouple the cross-coupling effects between the d-axis and the q-axis, which allows mounted permanent magnet (SMPM) synchronous motors. This paper presents an AC+DC measurement method for determination of the d-axis and...
This paper presents a new solution, which can completely remove the DC offset and make the dynamic error of flux observation smaller when using the modified voltage model compensated by rotor flux oriented current model. The modified voltage model with error compensation not only completely eliminates the integration drift, but also realizes errorless flux estimation in steady state and dynamic state...
The doubly-fed induction generator (DFIG) based wind turbines of today are often equipped with a crowbar, which can be used to limit the inrush rotor current and protect the ac excitation converter from damage via a set of resistors that are connected to the rotor windings of the DFIG. When the rotor current becomes too high due to the severe grid voltage dips on the transmission line, the crowbar...
In this paper, a novel 2-degree-of-freedom hybrid magnetic bearing is presented which the static bias magnetic flux is produced by polarized permanent magnet ring and control magnetic flux is produced by currents in control windings. The mathematical models are deduced based on the introduction of working mechanism of hybrid magnetic bearing (HMB). A practical prototype bearingpsilas parameters are...
Adding visualization function can facilitate the motor designer a lot in the CAD of small- and mid-type asynchronous electrical machinery. And so does it in visualization of design with the aid of the improvement of computer hardware and advancement of senior programming language. This paper talks about meaning of visualization of stator, rotor lamination and winding, as well as the programming method...
This paper presents the analysis and operation of doubly fed induction generator (DFIG)-based wind power generation system under unbalanced network voltage conditions. The limited voltage and current ratings, the control capabilities of both the grid-side and the rotor-side converter (GSC & RSC) for unbalanced network voltage compensation are investigated in detail. A new current control scheme,...
At present, structure design and performance optimization are the key points in the study of brushless doubly-fed machine (BDFM). By using ANSYS software, the finite element method (FEM) models of BDFM were established. These models have different rotor structures that are reluctance rotor with magnetic barriers, cage rotor with nested shorted-circuit windings, reluctance rotor with salient poles,...
Several types of interior permanent magnet synchronous motor have been utilized in the wide rage of applications. The characteristics of their cogging torque and average torque and d and q- axis inductance were clarified for the different shapes of rotor magnet and two types of stator windings. This paper clarifies the characteristics of radial attractive force and vibration for the different shapes...
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