Fractional-Order PI-Lead Controller Design of DC–DC Power Converter for Renewable Energy Applications

Abstract

Fractional-order controller plays a vital role in controller design of a real-time physical system such as DC–DC power converters used in renewable energy applications. Nowadays, world is moving toward sustainable energy systems. Incorporating sustainable power sources in microgrid system is the advanced step not only from financial but also from environmental perspective, and DC–DC power converter plays an important role to perform different tasks within the integrated system. Therefore, its precise control becomes a crucial task, and here, fractional-order controllers come into the picture due to its high flexibility and superior performance. This chapter deals with new generalized way of designing fractional-order proportional–integral with lead (FOPI-Lead) controller for DC–DC power converters. To attain the desired phase margin at any given gain cross-over frequency (GCF), the parameters of FOPI-Lead controller are tuned accordingly by solving the frequency-domain equations. In this chapter, the control technique has been implemented for a second-order non-ideal DC–DC buck converter. The simulation results confirm that the desired phase margin can be obtained at specified cross-over frequency by proper tuning the FOPI-Lead controller parameters. Due to the presence of additional tuning parameters and flexibility in design, the performance of FOPI-Lead controller is comparatively better than conventional PI controllers.KeywordsBuck converterFractional-order PI-Lead controllerGain cross-over frequency (GCF)Phase margin (PM)etc.