Wye-delta winding configuration for brushless operation of a wound field synchronous machine

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1165-1172
Author(s):  
Muhammad Ayub ◽  
Asif Hussain ◽  
Ghulam Jawad Sirewal ◽  
Byung-il Kwon
Keyword(s):  
Harmonic Component ◽  
Synchronous Machine ◽  
Induced Voltage ◽  
Element Analysis ◽  
Magnetomotive Force ◽  
Third Harmonic ◽  
Harmonic Currents ◽  
Drive Circuit ◽  
Inverter Topology ◽  
Circulating Currents

This manuscript proposes a wye-delta winding configuration for brushless operation of a wound field synchronous machine (BL-WFSM). In existing third harmonically excited BL-WFSM topologies, the additional third harmonic component of the stator magnetomotive force (MMF) was produced by an extra thyristor drive circuit or by utilizing an additional inverter. In the proposed single inverter topology, the stator winding is divided into two coil sets: the wye coil and delta coil. Triplen harmonic currents are produced owing to the delta coils set and start to circulate in the delta coils. This triplen harmonic circulating currents produce a triplen harmonic pulsating MMF in the airgap. The additional triplen harmonic pulsating MMF induces voltage in the rotor harmonic winding. This induced voltage in the harmonic winding is used to excite the rotor field. A 2D finite element analysis is performed, and the simulation results confirmed the operation principle of the proposed brushless topology.

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

2022 ◽  
Vol 13 (1) ◽  
pp. 16
Author(s):  
S M Sajjad Hossain Rafin ◽  
Qasim Ali ◽  
Thomas A. Lipo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Harmonic Component ◽  
Synchronous Machine ◽  
Stator Winding ◽  
The Novel ◽  
Machine Model ◽  
Element Analysis ◽  
Magnetomotive Force ◽  
Brushless Excitation

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.

scholarly journals Dual-Inverter-Controlled Brushless Operation of Wound Rotor Synchronous Machines Based on an Open-Winding Pattern

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2205 ◽  
Author(s):  
Syed Sabir Hussain Bukhari ◽  
Ghulam Jawad Sirewal ◽  
Faheem Akhtar Chachar ◽  
Jong-Suk Ro
Keyword(s):  
Harmonic Component ◽  
Current Component ◽  
Harmonic Current ◽  
Element Analysis ◽  
Third Harmonic ◽  
Time Harmonic ◽  
Wound Rotor Synchronous Machine ◽  
Field Excitation ◽  
Winding Machine ◽  
Dc Current

In an open-winding machine, three-phase stator currents can be controlled such that the input armature currents may contain the third-harmonic current component in addition to the fundamental. Considering this attribute of open-winding patterns, a harmonic current field excitation technique for a wound rotor synchronous machine (WRSM) is proposed in this paper based on the control of time-harmonic magneto-motive force. Two inverters connected to both terminals of the stator winding are controlled so that the input armature current generates an additional third-harmonic current component. This third-harmonic component generates a vibrating magnetic field that induces a current in the specially designed rotor harmonic winding. The current is supplied as DC current to the rotor excitation winding to generate a rotor field by using a full-bridge diode rectifier in order to achieve brushless operation. The proposed dual-inverter-controlled brushless operation for a WRSM is executed in ANSYS Maxwell using 2-D finite element analysis to validate its operation and electromagnetic performance.

scholarly journals Novel Single Inverter-Controlled Brushless Wound Field Synchronous Machine Topology

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1739
Author(s):  
Syed Sabir Hussain Bukhari ◽  
Ali Asghar Memon ◽  
Sadjad Madanzadeh ◽  
Ghulam Jawad Sirewal ◽  
Jesús Doval-Gandoy ◽  
...  
Keyword(s):  
Synchronous Machine ◽  
Current Control ◽  
Air Gap ◽  
Voltage Source ◽  
Stator Winding ◽  
Element Analysis ◽  
Third Harmonic ◽  
Dc Offset ◽  
Three Phase ◽  
Rotor Winding

This paper proposes a novel brushless excitation topology for a three-phase synchronous machine based on a customary current-controlled voltage source inverter (VSI). The inverter employs a simple hysteresis-controller-based current control scheme that enables it to inject a three-phase armature current to the stator winding which contains a dc offset. This dc offset generates an additional air gap magneto-motive force (MMF). On the rotor side, an additional harmonic winding is mounted to harness the harmonic power from the air gap flux. Since a third harmonic flux is generated in this type of topology, the machine structure is also modified to accommodate the third harmonic rotor winding to have a voltage induced as the rotor rotates at synchronous speed. Specifically, four-pole armature and field winding patterns are used, whereas the harmonic winding is configured for a twelve-pole pattern. A diode rectifier is also mounted on the rotor between the harmonic and field windings. Therefore, the generated voltage on the harmonic winding feeds the current to the field winding for excitation. A 2D-finite element analysis (FEA) in JMAG-Designer was carried out for performance evaluation and verification of the topology. The simulation results are consistent with the proposed theory. The topology could reduce the cost and stator winding volume compared to a conventional brushless machine, with good potential for various applications.

scholarly journals Brushless Field Excitation Scheme for Wound Field Synchronous Machines

2020 ◽  
Vol 10 (17) ◽  
pp. 5866
Author(s):  
Syed Sabir Hussain Bukhari ◽  
Ghulam Jawad Sirewal ◽  
Faheem Akhtar Chachar ◽  
Jong-Suk Ro
Keyword(s):  
Synchronous Machines ◽  
Harmonic Current ◽  
Element Analysis ◽  
Magnetomotive Force ◽  
Excitation Scheme ◽  
Third Harmonic ◽  
The Third ◽  
Harmonic Field ◽  
Three Phase ◽  
Field Excitation

A new harmonic field excitation technique for the brushless operation of wound field synchronous machines (WFSMs) is proposed in this paper. The proposed scheme involves conventional three-phase and single-phase inverters operating at different frequencies and supply input current to the armature winding simultaneously. This results in a composite output current of the inverters, which contains fundamental as well as the third harmonic current components. The fundamental is utilized to develop the stator field, on the other hand, the third harmonic is used for developing the pulsating magnetomotive force (MMF) in the airgap. This MMF produces a harmonic current in the harmonic winding of the rotor which is later rectified to inject field current to the rotor field winding. The theoretical analysis of the proposed technique is supported using 2-D finite element analysis (FEA).

Design and analysis of a PM-assisted brushless WRSM for improving torque characteristics

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1127-1134
Author(s):  
Ghulam Jawad Sirewal ◽  
Muhammad Ayub ◽  
Byung-il Kwon
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Harmonic Component ◽  
Torque Ripple ◽  
Analysis Tool ◽  
Element Analysis ◽  
Third Harmonic ◽  
Machine Structure ◽  
Starting Torque

This paper proposes a permanent magnet assisted brushless wound rotor synchronous machine (PMa–BL–WRSM) design. The proposed machine has the advantage of a high starting torque compared to existing BL–WRSM topologies. Additionally, the average torque increases and the torque ripple is reduced when the permanent magnet assisted machine structure is used. PMa–BL–WRSM operates on the principle of brushless excitation using zero-sequence, third-harmonic current generation in the stator windings. The third harmonic component is harnessed to induce a voltage in the harmonic winding which is mounted on the rotor. As there is no flux generated from filed winding in the starting, the starting torque of the machine is also zero. To overcome the problem, permanent magnets (PMs) are inserted in each field tooth to provide the initial source of flux on the rotor. Finite element analysis is performed with the PM–BL–WRSM, and the elicited results are compared with the basic machine structure. The proposed machine operation is verified using 2-D finite element analyses using the ANSYS Maxwell analysis tool.

scholarly journals Magnetic equivalent circuit model for unipolar hybrid excitation synchronous machine

2015 ◽  
Vol 64 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Emil Kupiec ◽  
Włodzimierz Przyborowski
Keyword(s):  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Synchronous Machine ◽  
Circuit Model ◽  
Effective Control ◽  
Induced Voltage ◽  
Magnetomotive Force ◽  
Magnetic Equivalent Circuit ◽  
Hybrid Excitation ◽  
The Impact

AbstractLately, there has been increased interest in hybrid excitation electrical machines. Hybrid excitation is a construction that combines permanent magnet excitation with wound field excitation. Within the general classification, these machines can be classified as modified synchronous machines or inductor machines. These machines may be applied as motors and generators. The complexity of electromagnetic phenomena which occur as a result of coupling of magnetic fluxes of separate excitation systems with perpendicular magnetic axis is a motivation to formulate various mathematical models of these machines. The presented paper discusses the construction of a unipolar hybrid excitation synchronous machine. The magnetic equivalent circuit model including nonlinear magnetization curves is presented. Based on this model, it is possible to determine the multi-parameter relationships between the induced voltage and magnetomotive force in the excitation winding. Particular attention has been paid to the analysis of the impact of additional stator and rotor yokes on above relationship. Induced voltage determines the remaining operating parameters of the machine, both in the motor and generator mode of operation. The analysis of chosen correlations results in an identification of the effective control range of electromotive force of the machine.

scholarly journals High-Harmonic Injection-Based Brushless Wound Field Synchronous Machine Topology

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1721
Author(s):  
Syed Sabir Hussain Bukhari ◽  
Fareed Hussain Mangi ◽  
Irfan Sami ◽  
Qasim Ali ◽  
Jong-Suk Ro
Keyword(s):  
High Harmonic ◽  
Current Injection ◽  
Harmonic Current ◽  
Element Analysis ◽  
Magnetomotive Force ◽  
Excitation Scheme ◽  
Three Phase ◽  
Harmonic Injection ◽  
Field Excitation ◽  
Electromagnetic Performance

This paper discusses the design and analysis of a high-harmonic injection-based field excitation scheme for the brushless operation of wound field synchronous machines (WFSMs) in order to achieve a higher efficiency. The proposed scheme involves two inverters. One of these inverters provides the three-phase fundamental-harmonic current to the armature winding, whereas the second inverter injects the single-phase high-harmonic i.e., 6th harmonic current in this case, to the neutral-point of the Y-connected armature winding. The injection of the high-harmonic current in the armature winding develops the high-harmonic magnetomotive force (MMF) in the air gap of the machine beside the fundamental. The high-harmonic MMF induces the harmonic current in the excitation winding of the rotor, whereas the fundamental MMF develops the main armature field. The harmonic current is rectified to inject the direct current (DC) into the main rotor field winding. The main armature and rotor fields, when interacting with each other, produce torque. Finite element analysis (FEA) is carried out in order to develop a 4-pole 24-slot machine and investigate it using a 6th harmonic current injection for the rotor field excitation to both attain a brushless operation and analyze its electromagnetic performance. Later on, the performance of the proposed topology is compared with the typical brushless WFSM topology employing the 3rd harmonic current injection-based field excitation scheme.

Imaging Cracks in Bones Using Acoustic Nonlinearity: A Simulation Study

2011 ◽  
Vol 97 (5) ◽  
pp. 728-733
Author(s):  
Yang Liu ◽  
Xiasheng Guo ◽  
Zhao Da ◽  
Dong Zhang ◽  
Xiufen Gong
Keyword(s):  
Time Reversal ◽  
Three Dimensional ◽  
Harmonic Component ◽  
Ultrasonic Signal ◽  
Long Bone ◽  
Third Harmonic ◽  
Acoustic Nonlinearity ◽  
The Third ◽  
Nonlinear Approach ◽  
Radial Depth

This article proposes an acoustic nonlinear approach combined with the time reversal technique to image cracks in long bones. In this method, the scattered ultrasound generated from the crack is recorded, and the third harmonic nonlinear component of the ultrasonic signal is used to reconstruct an image of the crack by the time reversal process. Numerical simulations are performed to examine the validity of this approach. The fatigue long bone is modeled as a hollow cylinder with a crack of 1, 0.1, and 0.225 mm in axial, radial and circumferential directions respectively. A broadband 500 kHz ultrasonic signal is used as the exciting signal, and the extended three-dimensional Preisach-Mayergoyz model is used to describe the nonclassical nonlinear dynamics of the crack. Time reversal is carried out by using the filtered third harmonic component. The localization capability depends on the radial depth of the crack.

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