http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A Self-Excitation Scheme for a Brushless Synchronous Generator
Ghulam Jawad Sirewal,Muhammad Ayub,Byung-il Kwon 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
This paper proposes a self-excitation scheme for a brushless wound rotor synchronous generator. The proposed generator excitation scheme uses thyristor switches to control zero-sequence third harmonic current flow to the neutral wire of the three-phase armature winding. In the generating operation when line three phase currents flow, thyristor switching creates current flowing to the neutral wire. This current is rectified and fed to an additional winding on the stator called stator harmonic winding. Current in the stator harmonic winding generates additional magneto-motive force (MMF) component along with the fundamental component which is generated from threephase armature winding. 2D finite element analysis in ANSYS Maxwell 19.0 is performed to validate the working of the self-excited brushless generator scheme.
Wide Speed-range Operation of a Dual-mode Wound Field Synchronous Machine
Muhammad Ayub,Qasim Ali,Ghulam Jawad Sirewal,Byung-il Kwon 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
This paper proposes a dual-mode wound field synchronous machine (WFSM) topology for wide speed operation. The machine stator has two winding, winding ABC-1 and ABC-2, and the current to each winding is supplied by a separate inverter. Contrary to the disadvantages in conventional brushed and brushless WFSM topologies, the proposed topology combines the advantage of achieving constant torque region by brushed operation in mode-I, and advantage of brushless in constant power region in mode-II. In mode-II, the difference in the two inverter currents creates an additional sub-harmonic magnetomotiveforce (MMF). The additional sub-harmonic is utilized for brushless operation. The advantages of the proposed topology are, constant torque region, brushless operation in constant power region, and robust rotor structure as the machine operates brushless though out constant power region. The wide speed operation is achieved by negative-daxis control along with the special inverter-current magnitude variation. A 2-D finite-element analysis is performed, and the proposed topology is analyzed.