Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title A Stable Startup Method of V/f Scalar Controlled Permanent Magnet Synchronous Motors
Authors Hyeon-Seong Kim ; Sang-Min Lee ; Kibok Lee
DOI 10.6113/TKPE.2020.25.5.395
Page pp.395-403
ISSN 1229-2214
Keywords I/f control; PMSM; Stable startup; Transition method; V/f control
Abstract This study presents a stable start-up strategy for v/f scalar-controlled permanent magnet synchronous motors (PMSMs). The v/f-controlled PMSMs easily lose synchronism under low-speed conditions if an insufficient stator voltage is applied to the machine due to errors in measured motor parameters and inverter nonlinearity, such as inverter dead time and on-state voltage drop. The proposed method adopts the I/f control method to ensure a stable start at low speeds and then switches to the v/f control method at medium speeds. A smooth transition method from I/f control to v/f control is proposed to minimize the oscillation of the stator current and rotor speed during transition. Moreover, the stability of the I/f and v/f control methods is analyzed using a small-signal model. Simulation and experimental results are provided to verify the performance of the proposed control strategy.