Linear Electric Machines, Drives, and MAGLEVs Handbook

2 Classifications and Applications of LEMs

Linear electromagnetic machines (LEMs) develop electromagnetic forces based on Faraday’s and Ampere’s laws, as described in Chapter 1, and produce directly linear motion. Linear motion may be either progressive (Figure 2.1a) or oscillatory (Figure 2.1b) [1–4]. Linear progressive motion even when experiencing back and forth, but nonperiodic, operation modes leads to LEMs whose topology differ (in general) from that of linear oscillatory machines (LOMs). The linear oscillatory motion takes place in general at resonance—when mechanical eigenfrequency equals the electrical frequency—to secure high efficiency in the presence of a strong springlike force (mechanical or even magnetic) [5].

In general, the ...