Study on Direct Thrust Control of Six-Phase PMSLM Based on Independent H-Bridge Inverters

On the basis of analyzing the circuit structure and working principle of six-phase permanent magnet synchronous linear motor (PMSLM) based on independent H-bridge inverters, the principle of direct thrust control (DTC) is introduced. In consideration of the independent structure of each phase winding, the spatial distribution of space voltage vectors is illustrated. Following the idea of space vector modulation (SVM), a direct thrust control strategy based on independent space phase voltage vector modulation (SVM-DTC) is studied. In each sector, the expected space voltage vector is synthesized by using independent phase voltage vectors on windings of two adjacent phases. Compared with traditional DTC, the simulation results show that the SVM-DTC using independent phase voltage vectors can effectively improve the thrust ripple and stator flux ripple, enhance the ability of anti-interference and achieve better dynamic characteristics.