The phenomenon of cogging torque in permanent magnet synchronous generators with concentrated windings is considered in this work. Dependence of fluctuation amplitude of the torque on width of stator slot opening is researched. The method to reduce the cogging torque by skewing of stator slot and opening of stator slot width equal distance between magnet and tooth on the rotor is described. The construction of this generator is obtained on the basis of numerical simulation results Index Terms-Torque, finite element method, permanent magnet machines.
This paper presents five latest methods and explains the last-new one with intention to reduce the cogging torque of permanent magnet synchronous generators (PMSG). The PMSGs are widely used in wind power plants (WPP) as one of the renewable power generation. One of the international goals is to expand the use of renewable energy sources. The main disadvantage of PMSG is the influence of magnetic interaction between the magnets and the teeth on the operation of PMSG, thus many scientists have been researching the possibilities to reduce the cogging torque. The magnetic field modelling software is used to obtain the values of PMSG cogging torque. The calculations in this software are based on finite element analysis. A methodology is created to obtain the 3D results from the 2D modelled magnetic field. The achieved results allowed to submit a patent. The new proposed method is researched allowing to receive the first results of PMSG optimal design, thus expanding the lower boundary of operating wind speed for WPP. Index Terms-Electromagnetic fields, finite element analysis, permanent magnet machines, torque measurement, wind power generation.
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.
The purpose of the paper is to analyze the possibility to use a magnetic coupler instead of lever actuated friction clutch, which is used in the wind plants between the shaft from turbine and the shaft from motor. There are analysed the construction parameters of magnetic coupler to obtain the necessary coupler's mechanical torque. The paper includes the calculation of a mechanical torque, applying program QuickField. In QuickField there is calculated magnetic field using finite element method (FEM).
In this paper the influence of basic design parameters (proportionality coefficient β and permanent magnets height h) on the mechanical torque for cylindrical magnetic coupler with rounded permanent magnets is researched. Such cylindrical magnetic couplers are often used in pumps and liquid mixers. At the beginning the design parameters and their relevance are explained. The mechanical torque is calculated applying the software QuickField. In the data analysis and for the coupler comparison the division of maximal mechanical torque on volume is taken as the main characteristic. Because of the planned optimization for the calculated variants there were synthesized few formulas, from which the most suitable were found (for all researched design parameters’ ranges). The formulas are synthesized using a program, which is created by Oskars Onzevs. The program for the formula synthesis is based on regression models, and the basic principles of it are explained. All the calculations for experimental and formula data are made for magnetic coupler’s design with one pole pair number p that is equal to three.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.