Linear motors in high-purity environments require full stainless steel (SS) encapsulation and contactless, i.e., inductive power transfer (IPT) to the moving sliders, where the movement of each slider is controlled with a dedicated attached driver stage. For powering the driver stages, toroidal transformer cores concentrically arranged with the stationary IPT primary winding, which spans the full motor stroke length, are employed to mitigate SS eddy current losses. The primary winding is supplied with a full-bridge converter through a compensation network that either compensates the voltage over the stray inductance (voltage-impressed operation) or ensures the constant primary winding’s current (currentimpressed operation). This paper explains the operating principle of both concepts and/or operation modes based on equivalent circuits and optimizes the operating frequency and the number of primary and secondary turns to maximize efficiency. Finally, we present an industry-like hardware demonstrator with two receivers (2×100W, 72V input and output voltage), and experimental measurement results that fully verify our analyses.
