ScholarWorks@동국대학교

초록

This paper proposes a deadbeat load torque observer (DB-LTO)-based deadbeat direct torque and flux control (DB-DTFC) technique to obtain an enhanced and stable transient response of surface-mounted permanent-magnet synchronous motor (SPMSM) drives. Different from the existing DTFC approaches which control only torque and flux, the proposed DB-DTFC incorporates the speed dynamics for improving the transient control performance. Notably, a DB-LTO is proposed for fast and accurate load-torque estimation while helping to efficiently cope with the system parameter discrepancies and nonlinearities. A mathematical proof of the stability of the proposed DB-LTO-based DB-DTFC strategy is presented via eigenvalue analysis of the closed-loop system. The overall control stability is also verified by appropriately selecting the control design parameters of the proposed observer and controller gains. The proposed strategy is evaluated via extensive experimental investigations using a prototype SPMSM drive equipped with TI-TMS320F28335 digital signal processor (DSP). The improved performance is verified regarding reduction in steady-state error (SSE, from 17% to negligible), less torque ripple up to 67%, overshoot and undershoot elimination (from 25% and 16% to almost 0%), and faster transient response up to 25%, primarily resulting from the proposed DB-LTO and achieved through the enhanced DB-DTFC design under critical load-torque and motor-speed variations with inaccurate model parameters. © 2013 IEEE.

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