Design of a SOFC/GT/SCs hybrid power system to supply a rural isolated microgrid. (1st June 2016)

• Record Type: Journal Article
• Authors: Camblong, Haritza; Baudoin, Sylvain; Vechiu, Ionel; Etxeberria, Aitor
• Is Part Of: Energy conversion and management. Volume 117(2016)
• Page Start: 12
• Page End: 20
• Publication Date: 2016-06-01
• Subjects: Hybrid power system -- SOFC -- Gas microturbine -- Supercapacitors module -- Multilevel 3LNPC converter -- Robust digital controller; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2016.03.006
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: A novel SOFC/GT/SCs HPS is connected to a rural microgrid through a 3LNPC inverter. An operating strategy that maintains the SOFC power at its rated value is defined. A robust digital controller that damps current oscillations is designed. The efficiency, power quality, lifetime, and robustness of the HPS are considered. An experimental test on an original HPS emulator validates the proposed solutions. Abstract: The aim of this research study has been to design a Hybrid Power System (HPS) which works with biogas and whose main components are a Solid Oxide Fuel Cell (SOFC), a Gas microTurbine (GT), and a module of SuperCapacities (SCs). The HPS is the only power source of a rural isolated microgrid. Its structure, operating strategy, and controller have been designed considering the following criteria: efficiency, power quality, SOFC lifetime and robustness in stability and performance. The HPS structure includes a unique power converter, a 3-Level Neutral Point Clamped (3LNPC) inverter that connects the HPS to the AC microgrid. Regarding the selected operating strategy, it consists in regulating the SOFC power output to its rated value. Thus, the SCs and the GT must respond to the power demand variations. On the other hand, a study of the HPS shows that its dynamic behavior is not linear. Therefore, a special attention is put on designing a robust HPS controller. The control model is identified and the robust digital controller is designed using the "Tracking and Regulation with Independent Objectives" method. Simulation and experimental results show how the proposed structure, operating strategy, and controller allow ensuring a good behavior of the HPS from the point of view of the abovementioned four criteria.