Modeling and Control of Large Shovel Converter Systems Integrated with Supercapacitor

In this paper, detailed modeling and control of the active front end (AFE) of AC drive mining applications specifically the shovel systems are presented. Through a nonlinear transformation and power balance fact, a linear model of the converter is developed which makes the controller independent of the operating points. Due to the low switching frequency operation of the shovel converter systems and issues regarding the rating and thermal management of the system, deploying DC chopper and crowbar circuits as a protective measure is unavoidable. As an alternative, supercapacitor is proposed not only to improve the controller performance but also to recover the regenerative energy instead of dissipating into the chopper circuits.