Self-Excitation of Low-Speed Inductor Generator

Abstract

The authors propose using the inductor generator with electromagnetic excitation in a wind-hydrogen independent power system for generation of the base load. They show that the remanent magnetic flux in such a generator is unable to create the electromotive force sufficient for its excitation from the cold start. This force and, therefore, power generation could be raised by introducing NdFeB permanent magnets in the slots of generator. Comparison of the conventional contactless generator and the generator with permanent magnets shows that the latter outperforms the former by such parameters as rotational speed range, efficiency and output, having at the same time smaller weight. The results of practical studies evidence that the inductor generator with a combined excitation system (electromagnetic excitation plus permanent magnets) can be a reliable power source in the independent wind-hydrogen systems.

A Design of Electrical Permanent Magnet Generator for Rural Area Wind Power Plant

“…The graphs line to line simulation result can be seen in Figure 4 MagNet Simulation produces Flux Linkage waves that have 120° phase difference. From the waves of the flux linkage can be observed the waves generated according to equation (7) so that the V-U, V-V, and V-W correspond to the Faraday laws [11], as stated in Equation 7and 8:…”

“…G.Dilev and Ose-Zala [7], has designed and built with the induction generator excitation system itself. Magnets used are NdFeB permanent magnets.…”

Improvement of self-excitation process in synchronous generator

“…6 -experimentally received coefficient of proportionality between excitation current and output voltage; i f -excitation current; ΔU vd -voltage drop across the diode; X s =2·π·f·L s -stator phase reactance; R ier =1.8 Ω -excitation winding resistance; R s =2.85 Ω -stator winding resistance.…”

“…Secondly, the course of the process influences the level of residual magnetism [6] and commutations in the rectifier which depends on stator windings inductance.…”

Self-Excitation System for Synchronous Generator

“…This type of generators are popular for large wind turbines, since the power electronic converter consumes only 30% of the generator output power, but they have some disadvantages, regarding the construction features [4], and also low generator residual magnetism, which is insufficient to create voltage from the cold start, therefore the use of this type of generators in autonomous power supply system without connection to the power grid is inefficient [5]. It was offered to use combined excitation system which includes electromagnetic excitation and a thin layer of permanent magnets built into the slots of excitation winding.…”