Electromagnetic, Mechanical and Manufacturing Properties for Cable Wound Direct-Drive PM Linear Generators for Offshore Environments

Author(s):  
Erik Hultman ◽  
Boel Ekergård ◽  
Mats Leijon

Renewable energy conversion in offshore environments, such as wave, wind and tidal energy, can potentially give a considerable contribution to the global electric energy demand. These harsh environments require robust generators with minimal need for maintenance at competitive costs. To reduce the generator cost, the electromagnetic design must be done with manufacturing in mind. An optimal design provides high electric efficiency, long device life-time, little need for maintenance and low manufacturing costs. Modern simulation tools can be used to optimize the electromagnetic design of a generator for a specific task and operation mode. Hereby both electromagnetic losses and material stresses can be reduced. Industrial robots might provide new possibilities to automate generator-specific manufacturing tasks. A generator design with a cable wound stator, surface mounted permanent magnets on the translator and direct-drive linear technology is investigated in this article. This concept has a simpler and more robust mechanical design, while both the electromagnetic losses and the need for maintenance are reduced. By reducing the number of generator assembly steps, manufacturing might also be facilitated. Further work is however needed in developing automated assembly methods and comparing them to conventional generator manufacturing.

Author(s):  
Hassan Ali ◽  
Erwan Sulaiman ◽  
Mahyuzie Jenal ◽  
Irfan Ali ◽  
Laili Iwani Jusoh ◽  
...  

The main objective of aerospace industry is to produce all electric aircraft (AEA) equipped by electrical devices in coming developments. Electrical machines that provide higher torque densities are gaining more interest for researchers to obtain sustainable direct-drive electrical propulsion system for aircraft applications. In addition to lesser weight and higher torque density, a machine should be “fault tolerant” to applied in aerospace applications. A novel machine for high starting torque, identified as flux switching machine (FSM) was established over the last decade. FSMs comprise all effective sources on stator including robust rotor structure. These machines exhibited higher “torque-to-weight ratios” and reliability. Nonetheless, the challenge of developing a machine suitable for aircraft applications goes far beyond electromagnetic design and much deeper into the field of mechanical systems than traditional ones. Thus, a new double stator (DS) hybrid excitation (HE) FSM design employing segmented rotor is proposed and analyzed in this research work. The suggested design for DS HE-FSM comprises of six field excitation coils (FECs) and six permanent magnets (PMs) as their excitation sources. In this research, investigation of DS HE-FSM is accomplished with respect to flux linkage, back EMF, cogging torque and torque analysis based on 2D FEA.


Author(s):  
Jan Kanuch ◽  
Peter Girovsky

The paper deals with analysis of properties of synchronous motor with external permanent magnets rotor. The mathematical analysis and equivalent circuit of permanent magnet synchronous motor (SMPM) is presented. In the parts of the paper the electromagnetic design, construction design and FEM Simulation of a SMPM is described and its properties are analysed. In the paper the results of simulation in Matlab/Simulink of torque, speed and current on the base mathematical model are shown.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3204
Author(s):  
Michał Sabat ◽  
Dariusz Baczyński

Transmission, distribution, and micro-grid system operators are struggling with the increasing number of renewables and the changing nature of energy demand. This necessitates the use of prognostic methods based on ever shorter time series. This study depicted an attempt to develop an appropriate method by introducing a novel forecasting model based on the idea to use the Pareto fronts as a tool to select data in the forecasting process. The proposed model was implemented to forecast short-term electric energy demand in Poland using historical hourly demand values from Polish TSO. The study rather intended on implementing the range of different approaches—scenarios of Pareto fronts usage than on a complex evaluation of the obtained results. However, performance of proposed models was compared with a few benchmark forecasting models, including naïve approach, SARIMAX, kNN, and regression. For two scenarios, it has outperformed all other models by minimum 7.7%.


2012 ◽  
Vol 6 (3) ◽  
pp. 161 ◽  
Author(s):  
O. Keysan ◽  
M. Mueller ◽  
A. McDonald ◽  
N. Hodgins ◽  
J. Shek
Keyword(s):  

2021 ◽  
Author(s):  
Austin C. Hayes ◽  
Gregory L. Whiting

Abstract Permanent magnet direct drive (PMDD) electric machines are advantageous due to higher efficiencies and lower maintenance concerns. For wind turbine generators, especially offshore turbines, this is advantageous to geared machines and is currently implemented by manufacturers such as GE, Siemens and Enercon. By nature, a direct drive machine must be larger than its geared counterpart in order to output the same power. As a result, the structural mass is larger and makes the machine prohibitively large. However, the structural mass and electromagnetic design is coupled and the electromagnetic criteria are an important consideration in the structural design. In this analysis, the electromagnetic design of a 5 MW PMDD generator was coupled to a triply periodic minimal surface (TPMS) lattice generator through means of an evolutionary algorithm. Finite element analysis (FEA) was used to determine the radial, torsional, and axial deformations under simulated wind turbine generator loading conditions subject to critical deflection criteria. Lattice functional grading was completed with the FEA deflection data in order to further optimize the structural mass. For the 5 MW test case, functional graded TPMS support structures maintained stiffness for a generator with a 32% higher force density with inactive mass 4% lower than baseline. This study suggests functional grading of TPMS lattice structures for wind turbine generators has the potential at significant mass savings.


2016 ◽  
Vol 37 (3) ◽  
pp. 79-93 ◽  
Author(s):  
Jan Wajs ◽  
Dariusz Mikielewicz ◽  
Michał Bajor ◽  
Zbigniew Kneba

AbstractThe results of investigations conducted on the prototype of vapour driven micro-CHP unit integrated with a gas boiler are presented. The system enables cogeneration of heat and electric energy to cover the energy demand of a household. The idea of such system is to produce electricity for own demand or for selling it to the electric grid – in such situation the system user will became the prosumer. A typical commercial gas boiler, additionally equipped with an organic Rankine cycle (ORC) module based on environmentally acceptable working fluid can be regarded as future generation unit. In the paper the prototype of innovative domestic cogenerative ORC system, consisting of a conventional gas boiler and a small size axial vapour microturbines (in-house designed for ORC and the commercially available for Rankine cycle (RC)), evaporator and condenser were scrutinised. In the course of study the fluid working temperatures, rates of heat, electricity generation and efficiency of the whole system were obtained. The tested system could produce electricity in the amount of 1 kWe. Some preliminary tests were started with water as working fluid and the results for that case are also presented. The investigations showed that domestic gas boiler was able to provide the saturated/superheated ethanol vapour (in the ORC system) and steam (in the RC system) as working fluids.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2759 ◽  
Author(s):  
Marco Palmieri ◽  
Salvatore Bozzella ◽  
Giuseppe Cascella ◽  
Marco Bronzini ◽  
Marco Torresi ◽  
...  

This work is focused on the design optimization of electrical machines that are used in small-scale direct-drive aerogenerators. A ducted wind turbine, equipped with a diffuser, is considered due to its enhanced power capability with respect to bare turbines. An annular type Permanent Magnet brushless generator is integrated in the turbine structure: the stator coils are placed in the internal part of the diffuser, whereas the permanent magnets are on an external ring connected to the turbine blade tips. Moreover, as regards the stator windings, the Printed Circuit Board (PCB) technology is investigated in order to exploit its advantages with respect to conventional wire coils, such as the increased current density capacity, the reduction of costs, and the enhanced precision and repeatability of the PCBs. An original design procedure is presented together with some scalability rules. An automated tool has been developed in order to aid the electrical machine designer in the first design stages: the tool performs multi-objective optimizations (using the Matlab Genetic Algorithm Toolbox), coupled to fast Finite Element analysis (through the open-source software FEMM) for the evaluation of the electromagnetic torque and field distribution. The proposed procedure is applied to the design of an annular PM generator directly coupled to a small-scale turbine for an urban application.


Author(s):  
Alberto Tama Franco

Wind technology is considered to be among the most promising types of renewable energy sources, and due to high oil prices and growing concerns about climate change and energy security, it has been the subject of extensive considerations in recent years, including questions related to the relative sustainability of electricity production when the manufacturing, assembly, transportation and dismantling processes of these facilities are taken into account. The present article evaluates the environmental impacts, carbon emissions and water consumption, derived from the production of electric energy of the Villonaco wind farm, located in Loja-Ecuador, during its entire life cycle, using the Life Cycle Analysis method. Finally, it is concluded that wind energy has greater environmental advantages, since it has lower values of carbon and water footprints than other energy sources. Additionally, with the techniques Cumulative Energy Demand and Energy Return on Investment, sustainability in the production of electricity from wind power in Ecuador is demonstrated; and, that due to issues of vulnerability to climate change, the diversification of its energy mix is essential considering the inclusion of non-conventional renewable sources such as solar or wind, this being the only way to reduce both the carbon footprint and the water supply power.


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