A Frequency-Modulated Space Vector Pulse-Width Modulation for Ripple Current Control of Permanent-Magnet Motor Drives

Various methods have been proposed to perform real-time ripple current estimation, which is critical for the performance improvement of ac motor drives. In this work, a novel ripple current prediction (RCP) approach is firstly proposed, which combines the advantages of both equivalent circuit based and machine model based methods. The proposed RCP method is accurate and effective in practical applications. Then a frequency-modulated (FM) space-vector pulse-width modulation (SVPWM) is proposed to actively control the ripple current by adjust the switching frequency on a cycle-by-cycle basis. The proposed FM-SVPWM has the capability to maintain the same amount of ripple current using reduced switching frequency or reduce the current ripple without increasing the switching frequency. Extensive simulation studies have been performed to validate the feasibility and effectiveness of the proposed methods.