A Medium Voltage DI-WRIM Industrial Drive Topology With Series-Connected DC-Link Controlled Using Dual-DCC Technique

This article proposes a Double-Inverter-fed Wound Rotor Induction Machine (DI-WRIM) based industrial drive topology having a series-connected dc-link for direct connection to higher voltage ac grids. This topology involves a 3L-neutral point clamped front-end converter, which gives a modular structure to the drive. In addition, a simple, less parameter-dependent Dual-Direct Current Control (Dual-DCC) algorithm is also proposed to control stator and rotor currents directly. This algorithm incorporates 3L-hysteresis comparators on
$\alpha \beta /\alpha _{r}\beta _{r}$
-component of current errors and uses six additional virtual voltage vectors for precise control of machine currents. Further, this article explores the position-sensorless control of the drive in sub and super-synchronous modes of operation. Simulation and experimental results are presented to validate the performance of the proposed drive topology and control algorithm. Additionally, the impact of the drive performance on the grid side has also been analyzed in transient and steady-state conditions.