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We have developed a method that uses AC with a DC bias to measure the inductances (Ld, Lq) of permanent magnet synchronous motors (PMSMs). Such motors are widely used in electrical equipment because they are highly efficient. Our method can be used to measure nonlinear characteristics of a PMSM, such as magnetic flux and inductance with cross-magnetization. We have compared our method with a conventional...
A new method to evaluate the steady state performance of a three-phase self excited induction generator based on conductance minimization is proposed. Among the priorities of this method are the absence of convergence problem, flexibility and the ability to be augmented to RC loads and loads with compensation. Simple methods to find the frequency, magnetizing reactance and minimum required capacitance...
Actuators working on the principle of thermoelasticity produce huge forces at very small shifts and may be used as prospective fixing elements in various industrial applications. The paper deals with the mathematical and computer modeling of their dynamic characteristics providing information about the time evolution of various important quantities (temperature rise, displacements, etc.). As the task...
This paper proposes a dynamic analysis method for a new spiral resonant actuator with two-degree-of-freedom employing the 3-D finite element method (FEM), and the dynamic characteristics of the actuator are quantitatively clarified using this method.
This paper presents a dynamic analysis method of a novel spherical resonant actuator using the three-dimensional finite element method (3-D FEM). In this method, the magnetic field equation is coupled with the electric circuit equation and the motion equation, and the mesh modification method using the Laplace equation is applied to the rotation of a spherical actuator.
An error estimation technique based on the L2 error norm is implemented in this paper for magnetostatic finite-element analysis. Convergence of both the global and local errors are used as indicators. The air gap is refined based on the rate of change in the calculated force and consists of layers. Results that highlight the accuracy of the combined methods for cogging torque calculations are displayed...
In induction motors with closed rotor slots the enclosure upper part of the rotor slot saturates during the machine operations, involving an additional non-linearity in the machines behavior. A simple locked rotor test gives prominence to this phenomenon. In fact, in this test the supply voltage versus adsorbed current characteristics are not linear. In the paper a single-phase induction motor equivalent...
This paper describes the self-excitation characteristics of a hybrid excitation single-phase synchronous generator with the features of both wound-rotor and PM synchronous machines. The wound field provides field regulation and allows the field-strengthening operation. The voltage compensation of the generator uses the negative-phase sequence field in the field winding.
Investigations for developing ultimate rating microturbogenerators based on modern materials were executed. Maximum permissible electromechanical and mechanical loads depending on minimum permissible core dimensions for microturbogenerators with rating of 100 and 200 kW and speed of rotation 30000-100000 rpm are determined. Complex simulation models for the purpose of chosen generator parameters optimization...
This paper describes the design and modeling of demonstration model of a linear permanent magnet actuator. This demonstration model used to verify the idea of using gas springs with linear permanent magnet actuator to produce strong vibrations for drilling applications.
The paper presents a methodology for determination of harmonic iron losses in laminated iron cores under sinusoidal excitation for various frequencies and sinusoidal pulse width modulated voltage excitations. The method is based on measurements performed by using a convenient Epstein device supplied by a sinusoidal and a SPWM source, which are stored and processed in a PC by using an appropriate data...
A high temperature superconducting (HTS) synchronous motor has been successfully designed, constructed and tested at the GREEN laboratory. Vectorfields is used to perform several simulations in order to investigate a better inductor concept bases on high power.
The aim of the preset work is the estimation and analysis of magnetic losses in stator cores of inductions motors, focusing in the areas where rotational losses due to rotational flux density vector are most important. The tool presented is used in this paper to determine and analyze rotational areas in seven different commercial induction motors. The main contribution of this work is that, with the...
Permanent magnet (PM) motors are favored for electric traction applications due to their high efficiency. The paper proposes an enhanced wheel internal permanent magnet (IPM) motor offering the advantages of PM machines along with excellent torque performance and high power density. The advantage of the proposed scheme is the high magnetic flux developed in the air gap which allows much higher values...
This paper describes the reduction method of cogging force in a linear motor. To decrease the cogging force, the method of phase set shift is presented with considering linear combination characteristics of cogging force. It is figured out that period of cogging force has relation with greatest-common-divisor (GCD) of pole pitch and teeth pitch. It is also verified that phase set shift has similar...
In order to realize a traction system with high efficiency and performance for a railway transit, many researchers have continued to study on a linear induction motor (LIM). However, most of researches are limited in LIM unit design. On a moving LIM, the change of an air-gap (it occurs by a construction tolerance of a secondary reaction plate) can lead to decrease a smoother ride and efficiency of...
This paper describes a semi-analytical modeling of an industrial electrical system operating in a pulse mode. It focuses principally on the transformer leakage inductances computation. First, the implemented analytical model is presented. It takes into account nonlinear elements behaviors, such as transformers, as well as other elements that behavior is both discontinuous and nonlinear, such as static...
Chokes are important elements in many power electronics circuits, for example in boost converters and current source inverters. Minimizing the choke's volume and mass is desirable in many applications. The main limit of an electromagnetic design lies in its thermal performance. Accurate prediction of the temperature within a new device is therefore very desirable. This paper presents a thermal analysis...
Flux probe is an on-line tool widely installed in large turbogenerators, used to detect shorted turns in the rotor winding. As the measures of the airgap flux are quite easy to perform, it is more complicated to analyze and give diagnostics. In order to help the operator to detect defects with the variations of the flux density curves, a complementary approach has been realized with FEM simulations...
This paper examines a sinusoidal current shape applied to the switched reluctance machine (SRM) control issues. A comparison between rectangular and sinusoidal current shapes allows to determine the typical application targeted. The two current shapes are experimentally tested and compared for both electrical optimization and noise reduction.
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