A thrust force characteristics measurement of the planar switched reluctance motor using flux linkage characteristics

In the advanced manufacture industry, high-precision planar motion is in high demand. Planar switched reluctance motors (PSRMs) have become attractive candidate for high-precision planar motion owing to the advantages of direct drive, high precision, quick response, low cost, and simple mechanical structure. Thrust force characteristics measurement is quite important for obtaining precise model and precise motion of PSRMs. Since the indelible friction exists in PSRMs, accurate thrust force characteristics are difficult to measure. This paper presents a systematic indirect thrust force characteristics measurement of a PSRM using flux linkage characteristics. With a dc-excitation method, flux linkage of the PSRM is obtained in terms of the measured phase current and voltage, and thrust force is computed by the flux linkage. Comparative studies of finite element method (FEM), direct and indirect thrust force measurements are discussed. Thrust force of the PSRM is experimentally measured by direct and indirect measurements. Compared with the thrust force by FEM, experimental results show that the indirect measurement is more accurate than the direct measurement, and the validity of the proposed indirect thrust force measurement of the PSRM is verified.