A non-Linear Model suitable for the Off-line Co-Simulation of Fault-tolerant PM Motors

Abstract

This paper presents a dynamic model suitable for accurate co-simulation of fault-tolerant permanent-magnet motor drives featuring independent-phases structure. The model is developed in a circuital form where the usual inductive parameters and back-EMF coefficient are replaced by current and rotor position dependent functions, so that the exact electromagnetic nature and geometry of the machine is accounted over the large flux-current operating range. The model functions are pre-computed by a finite element method analysis of a single phase of the machine, once the magnetic independence among the phases has been verified. Then, the circuital model is solved by a dynamical simulator which implements also the drive system, converter and control, following on the off-line co-simulation approach. The proposed model is validated by experiments carried on a fault-tolerant five-phase permanent-magnet motor-drive for aeronautical application, controlled by BLDC technique.

Existing System

Time-Stepping Technique.

Proposed System

This paper demonstrates that the fault-tolerant PM motors with alternate teeth windings structure can be represented by the straightforward superposition of the effects of each single phase assumed to operate alone. In this paper a dynamic non-linear model suitable for accurate co-simulation of fault-tolerant Permanent Magnet (PM) motors with independent-phases structure. The model is arranged in a circuital form where the usual inductive parameters and back-EMF coefficient are replaced by current and rotor position dependent functions, so that the large flux-current operating range of fault-tolerant machines is covered. Based on the off-line co-simulation approach, the model functions are pre-computed by a FEM analysis of a single phase of the machine, once the magnetic independence among the phases has been verified. Then, the non-linear model is solved by a dynamical simulator which implements both the machine and the drive system (converter and control). The proposed model is validated by experiments carried on a fault-tolerant five-phase PM motor-drive for aeronautical application, controlled by BLDC technique.

Architecture

Off-line co-simulation of electrical drives