A Series-Connected Three-Level Inverter Topology for Medium-Voltage Squirrel-Cage Motor Drive

A Series-Connected Three-Level Inverter Topology for Medium-Voltage Squirrel-Cage Motor Drive

The Induction motor drives with voltage source inverters. Also the voltage waveforms of traditional two level inverter fed Induction motor shows that the voltage across the motor contains not only the required “fundamental” sinusoidal components, but also pulses of voltage i.e. “ripple” voltage. Moreover the voltage waveforms produced by the inverter has sharp edges. The rate of change of voltage with respect to time i.e. dv/dt is very high at these edges, of the order of 500–5000 V/μs.The two-level inverter topology has attracted attention in low power low voltage drive applications where as Three-Level inverter topology has attracted attention in high power High performances voltage drive applications. Single-phase VSI cover low-range power applications and three-phase VSI cover the medium- to high-power applications.