No abstract

In the last decade, the interest for higher reliability in several industrial applications has boosted the research activities in multiphase permanent magnet synchronous motors realized by multiple three-phase winding sets. In this study, a mathematical model of an asymmetric surface-mounted six-phase permanent magnet synchronous motor under high resistance connections was developed. By exploiting the intrinsic properties of multiphase machines in terms of degrees of freedom, an improved field-oriented control scheme is presented that allows online fault detection and a quite undisturbed operating condition of the machine under high resistance connections. More specifically, the proposed strategies for online fault-detection and fault-tolerance are based on the use of multi-reference frame current regulators. The feasibility of the proposed approach was theoretically analyzed, then confirmed by numerical simulations. In order to validate experimentally the proposed strategies, the entire control system was implemented using TMS-320F2812 based platform.

This paper introduces a novel, active flux based, motion-sensorless vector control system for dc-excited synchronous motor, suitable for wide speed range applications. The active flux vector, defined as the torque producing flux, is aligned always along the rotor d axis and renders the machine model as with nonsalinent poles magnetic saturation. This vector is obtained from the estimated stator-flux vector minus L q i s vector, via a combined current-voltage model stator-flux observer, and through L q (i m ) depending on the total magnetization current. This way, the rotor position and speed estimation is simplified and wide speed range control is feasible. The paper introduces all components of the proposed system including a novel commissioning procedure for magnetization curves identification and a novel method for initial rotor position estimation. Details of control system implementation on DSP controller test platform and plenty of experimental test results for a traction system using dc-excited synchronous motor with 80 Vdc battery are presented. The test results fully validated the proposed solutions and show high performance starting from 15 rpm with heavy load disturbance rejection and rather quick torque response.