Robust control systems for modern power electronics: applications and challenges

Abstract

Summary form only given. Power electronics has had rapid development in the last decade which has resulted in wider real-life applications at present. Along with the above, power converters lay the foundations of our future life by providing us with alternative and long-term solutions for environmentally clean renewable energy resources. A variety of power converter topologies have been developed in the past, and many new topologies are realised every day. While these converters are required to operate under a wide range of system conditions, the majority of the existing control system designs are based on tuning control gains at nominal conditions. As such gains can be tuned for particular operational condition(s), any out-of-nominal operation may cause converter control system to collapse. Secondly, most of existing designs disregard coupling effects in the plant dynamics results of which could be unsatisfactory performance at the operational envelope. In addition, there are inherent perturbations in power converters that cannot be compensated by such tuned controllers. Parametric uncertainties due to electrical elements, transportation/computational delays (as complex-valued uncertainties), sufficiently large load variations, voltage source distortions, unmeasured external disturbances (like faults), and sensor noises are examples of dominant perturbations that could affect the operation of power converters. Advanced robust control system designs can aid development for power converters with improved output performance. Besides, they offer clear optimisation and design guidelines to reduce the cost and size of converters. The goal of this talk is to highlight the benefits and capabilities of robust multivariable feedback control systems design in challenging power electronics applications. Along with a brief review on the pragmatic robust control design, results of such advanced designs in a number of power electronics and power systems control applications will be illustrated in this plenary paper.