Affiliations: [a] Beijing Key Laboratory of Thermal Science and
Technology, Technical Institute of Physics and Chemistry, Chinese Academy of
Sciences, Beijing, China
Correspondence:
[*]
Corresponding author: Huiming Zou, Beijing Key Laboratory of
Thermal Science and Technology, Technical Institute of Physics and Chemistry,
Chinese Academy of Sciences, Beijing 100190, China. Tel.: +86 010 82543433;
Fax: +86 010 82543696; E-mail: [email protected]
Abstract: The electromagnetic transduction coefficient has a strong influence
on efficiency as well as the sensorless control of linear oscillation
electrical machine (LOEM). This paper presents a reciprocal LOEM method for
measurement of the electromagnetic transduction coefficient, to investigate the
effect of the magnet length on the characteristics of the transduction
coefficient. The result shows that the transduction coefficient has two
regimes, a constant regime and a nonlinear regime. As the harmonic distortion
begins to appear in the induced electromotive force, the electromagnetic
transduction coefficient passes from the constant regime to the nonlinear
regime, and the corresponding stroke is defined as critical stroke. The range
of constant regime equals the observed critical stroke, and the critical stroke
is 8.81 mm and 10.78 mm when the length of the permanent magnet is 11 mm and 13
mm respectively. The relationship among the geometrical dimension of yoke and
permanent magnet, the critical stroke and the stroke of the LOEM are carefully
investigated. Then optimal lengths for both the yoke and the permanent magnet
are suggested for the LOEM design with the rated stroke, to achieve the highest
efficiency and least material cost simultaneously.
