Comparative Study of Electric Machines for Stirling Generator Application

Abstract

The choice of a machine for an application and a given specification remains a complex problem. This will involve, for example, bringing together criteria such as performance, space-saving, economic, reliability, little acoustic noise, and others. The best selection to fulfil all constraints is an important step for the conception plan to come true. This work focus on Stirling Engine based Generator and study all types of rotating machines which can give maximum electric power. For any of them that satisfied the minimum requirement for the design project, we solve Maxwell’s equations to determine electromagnetic values and evaluate their output power. The purpose is to set up a conceptionmodel and combines the electromagnetic and thermal study of the generators. We also use FiniteElementMethod(FEM)tocomparetheperformancesoftheelectricgeneratorsfor the best choice. Results show that for applications not requiring bigger output power, the major criterion for the selection is the optimal magnetic induction created by the inducer in the stationary part of the machine. For three types of rotating machines that satisfy the minimum requirement mainly permanent magnet machine (PM), switched reluctance machine (SRM) and induction machine (IM), we assume that the maximum rotating speed supply by Stirling engine is 1200 rpm. The simulation results show 82.90% efficiency for PM machine, 73.04% for IM and 70.50% for SRM. For design projects such as Stirling generators, a permanent magnet (PM) machine satisfies many comparison criteria such as maximum power at low speed (2.1 kW), torque density (20.03) and high efficiency. Beyond revealing a selection method for a conception, this work lay down a step-by-step model for engineers and scientists for the crucial stage of the design and manufacturing.