Sponsor : LS 산전 (LSIS Co. LTD)

Background

In an electrolytic-capacitor-less inverter, the dc-link voltage is fluctuating at six times the frequency of the input three-phase source due to its small dc-link capacitance. Hence, the decoupling of the fluctuation and maximum utilization of the dc-link voltage is a major issue in the electrolytic-capacitor-less inverter. In this work, the HVMC (Hexagon Modulation Voltage Control) methodology is employed to increase the voltage utilization of the inverter in the flux-weakening operation of an induction motor. With the proposed flux-weakening strategy, the operating speed of the induction machine is extended above the base speed without any stability problems.