A Simplified Subdomain Analytical Model for the Design and Analysis of a Tubular Linear Permanent Magnet Oscillation Generator

We present a simplified 2-D analytical subdomain model to predict the open-circuit magnetic field of a tubular linear permanent magnet oscillation generator (T-LPMOG) to account for its primary and secondary end effects. At present, the magnetic field calculations of the T-LPMOG are typically analyzed in cylindrical coordinates, and the end effect is neglected accordingly to apply the periodic boundary. In this paper, a simplified 2-D analytical subdomain model in polar coordinates is proposed to consider the end effect. First, a coordinate transformation method is adopted to establish the 2-D subdomain analytical model, the cylindrical coordinates are converted into polar coordinates, and the T-LPMOG is analyzed under this new coordinate system. Next, the subdomain method is used to analyze the analytical model by solving Laplace's equation and the Poisson equation. Based on the simplified analytical model, the flux density and back-electromotive force are obtained. The analytical results are verified using the finite element analysis (FEA) method, and the computational times compared with the FEA method are provided. Finally, a T-LPMOG prototype is manufactured and tested, and the results show that the proposed analytical model can be useful in the initial design and optimization of the T-LPMOG.