A Phase-Domain Model of Dual Three-Phase Segmented Powered Linear PMSM for Hardware-Assisted Real-Time Simulation

Abstract

In this article, a hardware-assisted real-time simulation phase-domain (PD) model of a dual three-phase segmented powered linear permanent magnet synchronous machine (SP-LPMSM) used in electromagnetic drive is established. The model is able to consider the end-effect, saturation effect, coupling effect, and open-phase fault conditions, which are specially occurs in the segmented structure in SP-LPMSM. The unbalanced inductances and saturation effect caused by the segmented structure are investigated and a simplified look-up table for inductances is introduced. Additionally, to accurately evaluate the coupling effect, the permanent magnet (PM) flux linkage is decoupled into the product of unit PM flux linkage and coupling coefficient. In order to avoid the numerical impulse caused by the derivative in the progress of calculating back-EMF, sigmoid function is adopted to express the coupling coefficient. Meanwhile, to make the PD-model compatible with the open-circuit fault conditions, incidence matrices and current constraint matrices are introduced to unify the PD-models with different winding connection types and open circuit faults into one general form. The PD-model realized in field-programmable gate arrays (FPGA) based hardware is validated in comparison with finite-element analysis results.