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).

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.

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.

A New Control Strategy of Five-Phase Permanent-Magnet Motor Drives with a Third Harmonic Current Injection

2011 ◽  
Vol 464 ◽  
pp. 191-194
Author(s):  
Guo Hai Liu ◽  
Li Hao Yan ◽  
Duo Zhang ◽  
Wen Xiang Zhao
Keyword(s):  
Permanent Magnet ◽  
Harmonic Component ◽  
Motor Drives ◽  
Permanent Magnet Motor ◽  
Harmonic Current ◽  
Third Harmonic ◽  
Torque Density ◽  
Brushless Dc ◽  
The Third ◽  
Three Phase

In this paper, a five-phase permanent-magnet (PM) brushless dc (BLDC) motor is investigated, which has almost trapezoidal back electromotive force(EMF) due to its concentrated windings. Since the third harmonic component in the magnetic field is utilized, the presented five-phase BLDC motors have a higher torque density over conventional three-phase ones, in which the third harmonic current is injected. This paper proposes a new five-phase transformation system, by which the vector control is easily applicable to five-phase BLDC motors. Finally, the results verify the validity of the proposed method.

scholarly journals Third harmonic current injection into highly saturated multi-phase machines

2017 ◽  
Vol 66 (1) ◽  
pp. 179-187
Author(s):  
Felix Klute ◽  
Torben Jonsky
Keyword(s):  
Current Injection ◽  
Saturation Level ◽  
Permanent Magnet Synchronous Machines ◽  
Flux Linkage ◽  
Harmonic Current ◽  
Fem Model ◽  
Third Harmonic ◽  
The Third ◽  
Rotor Flux ◽  
Multi Phase

Abstract One advantage of multi-phase machines is the possibility to use the third harmonic of the rotor flux for additional torque generation. This effect can be maximised for Permanent Magnet Synchronous Machines (PMSM) with a high third harmonic content in the magnet flux. This paper discusses the effects of third harmonic current injection (THCI) on a five-phase PMSM with a conventional magnet shape depending on saturation. The effects of THCI in five-phase machines are shown in a 2D FEM model in Ansys Maxwell verified by measurement results. The results of the FEM model are analytically analysed using the Park model. It is shown in simulation and measurement that the torque improvement by THCI increases significantly with the saturation level, as the amplitude of the third harmonic flux linkage increases with the saturation level but the phase shift of the rotor flux linkage has to be considered. This paper gives a detailed analysis of saturation mechanisms of PMSM, which can be used for optimizing the efficiency in operating points of high saturations, without using special magnet shapes.

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