Sophisticated adjustable speed drives (ASDs) have for decades been an ever-increasing part of industrial automation and control systems and this is set to continue with the advent of smart grid systems. The control schemes in the drives themselves have continued to evolve to take advantage of improvements in power electronic technology and to meet modern challenges and application requirements in the utility environment.
One particular trend is the emergence of active front-end drives, in which advanced control techniques, together with energy storage in the DC link of the drive power electronics, aim to allow motor control drives to exhibit increased immunity to power quality problems, in particular voltage dips. The ability to test the impact of power quality events on such drives, as well as the interaction of the drives themselves with other protection and control equipment elsewhere in the system during such events, will be of obvious importance in future, in particular with the increased penetration of such technology in future into smart grid systems, and, very importantly, because of the unique characteristics of such controls in each manufacturer’s proprietary implementations.
This presentation describes an investigation into the use of real-time digital simulators as a tool for hardware-in-loop testing of commercial adjustable-speed drive control hardware in order to evaluate the performance of these drives under realistic fault contingencies in an upstream utility power system supply network, rather than relying on limited and simplistic voltage dip tests often used in such testing. The presentation also presents some new developments in commercial adjustable-speed drive control hardware that have emerged since this project began that could make it significantly easier to interface such hardware in closed loop with a real-time simulator for future such studies.
Palhad, B. S. Rigby • University of KwaZulu-Natal