Passivity-based control system for stand-alone hybrid electrogenerating complex

Abstract

The desire for energy independence presupposes the use of various types of elements for energy generation from renewable sources, for the stand-alone operation of which energy storage devices are required. A power generation complex created in this way must perform a number of tasks that are formed by the energy management system. The control system performs these tasks and ensures proper static and dynamic characteristics of this complex with many inputs and outputs. The results of recent world researches, as well as the authors experience of this work, show that, for creating such control systems, it is advisable to use Passive-Based Control (PBC), presenting the control object as a Port-Controlled Hamiltonian (PCH) system. Thanks to the developed method of additional interconnections and damping injection (Interconnection & Damping Assignment - IDA) passive control provides ample opportunities to adjust the control effects, while ensuring the asymptotic stability of the system as a whole. This is particularly useful in the complex system considered in this paper that includes both a hybrid power plant for electricity generation from the sun and wind and a hybrid energy storage unit consisting of the battery and supercapacitor module. This article shows the procedure of PBC system synthesis, according to which three structures of control influence formers (CIF) were designed and investigated. These structures have different combinations of additional interconnections and damping, which allows forming the desired energy flows inside the closed-loop system and therefore provide desired control results. Among them, there are tasks of maintaining voltages on the DC bus and the supercapacitor module at reference levels, and the smoothness of the battery current transients. A comparative simulation studies were performed on a computer model of the power generation complex with synthesized control systems, which was created in the MATLAB/Simulink environment. It showed the efficiency of their work and the advantages of different CIF structures.