A new initial‐rotor‐position estimation method for SPM synchronous motors using spatially rotating high‐frequency voltage: A dynamic simulator approach taking flux saturation phenomena into account

Abstract

AbstractFirst, this paper proposes a new dynamic mathematical model of surface‐mounted permanent magnet synchronous motors (SPMSMs) with flux saturation phenomena, in a stationary reference frame. Second, based on the dynamic model, this paper establishes new dynamic simulators taking flux saturation phenomena into account, which act as very powerful tools for developing initial‐rotor‐position estimation methods for SPMSMs. Third, this paper proposes a new initial‐rotor‐position estimation method for SPMSMs. The proposed method is so simple that it inputs a spatially rotating high‐frequency voltage to SPMSMs, measures current output, and can estimate directly rotor position of N‐pole through norm evaluation of the current. The method exploits flux saturation phenomena inherent to SPMSMs and is insensitive to all motor parameters. According to experiments, the maximum estimation error is about ±0.035 rad (±2○) in terms of mechanical angle, which is comparable to sensor mounting error and is sufficiently small for initial drive of SPMSMs. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(3): 63–73, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20241