A Novel Sub-Harmonic Synchronous Machine Using Three-Layer Winding Topology

This paper proposes a novel brushless synchronous machine topology that utilizes stator sub-harmonic magnetomotive force (MMF) for desirable brushless operation. The sub-harmonic MMF component that is used in this novel topology is one fourth of the fundamental MMF component, whereas, in previous practices, it was half. To achieve the brushless operation, the novel machine uses a unique stator winding configuration of two sets of balanced 3-phase winding wound in 3 layers. For the rotor, additional winding is placed to induce the sub-harmonic component to achieve the brushless excitation. Unlike its predecessors, it utilizes maximum allowable space in the stator to house conductors in all of its slots. To implement the topology, 8-pole, 48-slot sub-harmonic brushless synchronous machine model has been designed. A 2-D finite element analysis (FEA) is used to simulate and validate the performance of the novel machine as a motor. The proposed topology shows better average torque than the existing sub-harmonic wound rotor brushless synchronous machine topologies.

A New Design Procedure for Rotor Laminations of Synchronous Reluctance Machines with Fluid Shaped Barriers

A new procedure for the design and optimization of the rotor laminations of a synchronous reluctance machine is presented in this paper. The configuration of the laminations is symmetrical and contains fluid-shaped barriers. The parametrization principle is used, which executes variations in the lamination geometry by changing the position, thickness and shape of the flux barriers. Hence, the optimization procedure analyzes the various configurations through finite element simulations, by means of the communication between MATLAB and Flux 2D. In the post processing stage, the best geometry which optimizes mean torque, torque ripple, efficiency and power factor is selected. Once the best rotor configuration is defined, further investigations allow improving its performance by modifying the current angle, the stator winding and the thickness of the radial ribs.

The Diagnostics of the rotor misalignment of a permanent magnet motor

A mathematical model of the magnetic field in the working gap of a brushless motor is considered in a case of rotor misalignment arising during manufacture, for example, due to defects in end shields, or in operation due to bearing wear. a gap in a uniform (circular ring). The stator gearing is taken into account on average using the Carter coefficient, the magnetic field in the inhomogeneous air gap, created by the rotor magnets and the stator winding current, is assumed to be plane-parallel, having a two-dimensional character. It was found that the rotor misalignment associated with the rotational movement of the eccentricity causes nonsinusoidality of the idle EMF and pulsation of the electromagnetic moment with a frequency 3p times higher than the rotor speed. When the eccentricity is stationary, a variable EMF is induced along the rotor shaft, causing an alternating current in the circuit: shaft-bearings-bearing shields-stator housing. To clarify the nature of the defect in order to identify the actual misalignment of the rotor, it is recommended to control currents and voltages using specialized software and hardware complexes for spectrum analysis.

Frequency Analysis of Partial Short-Circuit Fault in BLDC Motors with Combined Star-Delta Winding

This paper analyses the condition of a partial short-circuit in a brushless permanent magnet motor. Additionally, the problem was analysed for three stator winding configurations: star, delta and star-delta connection. The paper presents an original mathematical model allowing a winding configurations to be analysed. What is more, the said mathematical model allows taking account of the partial short-circuit condition. Frequency analysis (Fast Fourier Transform—FFT) of the artificial neutral point voltage was proposed for the purpose of detecting the partial short-circuit condition. It was demonstrated that a partial short-circuit causes a marked increase in the diagnostic frequencies of the voltage signal. The proposed brushless permanent magnet motor diagnostic method is able to detect the fault regardless of the stator winding configuration type.

Application of Genetic Algorithm for Inter-Turn Short Circuit Detection in Stator Winding of Induction Motor

This paper presents a new method of inter-turn short-circuit detection in cage induction motors. The method is based on experimental data recorded during load changes. Measured signals were analyzed using a genetic algorithm. This algorithm was next used in the diagnostics procedure. The correctness of fault detection was verified during experimental tests for various configurations of inter-turn short-circuits. The tests were run for several relevant diagnostic signals that contain symptoms of faults in an examined cage induction motor. The proposed algorithm of inter-turn short-circuit detection for various levels of winding damage and for various loads of the examined motor allows one to state the usefulness of this diagnostic method in normal industry conditions of motor exploitation.

Intensifications reactive power during of asymmetric network outages in dual-stator winding generators

<span lang="EN-US">The paper proposes a protection to dual stator generator, reluctance rotor, from asymmetrical fault. Which prevents the dual stator generator, reluctance rotor, from electrical sage through working process in order to avoid any interruption in the generator-grid connection. The procedure consummated with injecting suitable reactive power during the fault period. The proposed method that makes it possible for wind turbine application via dual stator winding generators (DSWRG) synchronous mod to stay connected to the grid during asymmetrical faults. It has been built according to trusted simulating mode considering all tested parameters according to experiment work. The expirment, consider the DC link side stability and care about the behavior and performance of machine side parameter. As well the machineability is evaluated to ride through asymmetrical fault by observing the secondary side current which has a big role in saving grid side converter. The control takes a response within 200 ms after fault trigger recognition. The generator ability of dynamically remaining connected stable and existing in the network, which is sustained a series voltage disturbance by injecting appropriate amount of reactive power. The main interest required in this paper is the capability of a machine to overcome the asymmetrical fault.</span>

Pulse Width Modulation Analysis of Five-Level Inverter- Fed Permanent Magnet Synchronous Motors for Electric Vehicle Applications

In recent times, intense research has been focused on the performance enhancement of permanent magnet synchronous motors (PMSM) for electric vehicle (EV) applications to reduce their torque and current ripples. Permanent magnet synchronous motors are widely used in electric vehicle systems due to their high efficiency and high torque density. To have a good dynamic and transient response, an appropriate inverter topology is required. In this paper, a five-level inverter fed PMSM for electric vehicle applications, realized via co-simulation in an electromagnetic suite environment with a reduced stator winding current of PMSM via the use of in-phase disposition (PD) pulse width modulation (PWM) techniques as the control strategy is presented. The proposed topology minimizes the total harmonic distortion (THD) in the inverter circuit and the motor fed and also improves the torque ripples and the steady-state flux when compared to conventional PWM techniques. A good dynamic response was achieved with less than 10A stator winding current, zero percent overshoot, and 0.02 second settling time synchronization. Thus, the stator currents are relatively low when compared to the conventional PWM. This topology contribution to the open problem of evolving strategies that can enhance the performance of electric drive systems used in unmanned aerial vehicles (UAV), mechatronics, and robotic systems.

METHOD OF VECTOR PRIVATE CONTROL OF ASYNCHRONOUS ELECTRIC DRIVE

Анализируется проблематика векторного частотного управления асинхронным электроприводом, широко применяемым в качестве исполнительного элемента в рамках современных средств построения обрабатывающих комплексов, разрабатываемых в машиностроительной отрасли. Предлагается вариант частотно-регулируемого асинхронного электропривода, управляемыми величинами которого являются полярные координаты вектора тока в обмотке статора. В данном варианте применяется закон управления, согласно которому угол между векторами тока в обмотке статора и потокосцеплением обмотки ротора не меняется. Управление скоростью вращения электропривода и электромагнитным моментом реализуется заданием модуля тока обмотки статора. При этом формирование угла поворота вектора тока обмотки статора, зависящего от модуля величины потокосцепления роторной обмотки и значения скольжения асинхронного двигателя, дает возможность сохранять постоянным угол между векторами тока обмотки статора и потокосцеплением обмотки ротора, что, в свою очередь, реализует направленное формирование переходных процессов в асинхронном двигателе. Рассматриваемый вариант частотно-регулируемого асинхронного электропривода может найти применение в производственных механизмах, в которых быстродействие не является определяющим критерием функционирования привода, а важно плавное регулирование электромагнитного момента и возможность его ограничения во всех режимах работы. Данный способ управления характеризуется тем, что электромагнитный момент определяется исключительно модулем тока обмотки статора, а контур регулирования скольжения используется для реализации закона поддерживания постоянства угла между током обмотки статора и потокосцеплением обмотки ротора The article analyzes the problems of vector frequency control of asynchronous electric drive, widely used as an executive element in the framework of modern means of constructing processing complexes developed in the machine-building industry. Here we propose a variant of a frequency-controlled asynchronous electric drive, in which the polar coordinates of the current vector in the stator winding are the controlled quantities. In this variant, the control law is applied, according to which the angle between the current vectors in the stator winding and the flow coupling of the rotor winding does not change. The control of the speed of rotation of the electric drive and the electromagnetic torque is realized by setting the current module of the stator winding. At the same time, the formation of the angle of rotation of the current vector of the stator winding, depending on the modulus of the magnitude of the flow coupling of the rotor coil and the sliding value of the asynchronous motor, makes it possible to keep the angle between the current vectors of the stator winding and the flow coupling of the rotor winding constant, which in turn implements the directional formation of transients in the asynchronous motor. The considered variant of a frequency-controlled asynchronous electric drive can be used in production mechanisms in which speed is not a determining criterion for the operation of the drive, but smooth regulation of the electromagnetic torque and the possibility of its limitation in all operating modes is important. This control method is characterized by the fact that the electromagnetic moment is determined exclusively by the current module of the stator winding, and the slip control circuit is used to implement the law of maintaining the constancy of the angle between the current of the stator winding by the flow coupling of the rotor winding