High Dynamic Control of a Three-Level Voltage Source Converter Drive with Synchronous Motor and Active Front End

A high dynamic control system for the Alspa VDM 7000 medium voltage drive was implemented, which provides fast torque response times of a few milliseconds despite the typically low switching frequency of GTO thyristors that is necessary to achieve high efficiency. The drive system consists of a three-level voltage source converter with active front-end and a synchronous motor. The drive has most recently been applied for a main strip mill. It provides a maximum of 8.3 MW mechanical power with a rated motor voltage of 3 kV.