Skip to main content

Pv systems technology development for the gradual penetration of photovoltaics into island grids

Exploitable results

The aim of this project was to clearly indicate a way to transform island grids powered by diesel generators into hybrid ones with the main power contribution coming from distributed PV inverters. The daily production and consumption cycles will be balanced with battery storage allowing further the evolution to a 100% renewable energy system. The development of modular components (hardware and software) needed for this purpose was realised as well. Throughout the evolution process of a typical island system, the Grid Master Control System (GMC) goal is to achieve relevant improvements in terms of power availability, frequency and voltage regulation, fuel and maintenance savings, air emission and noise reduction. The operations studies in the project were performed by ISET (Germany). Distributed PV inverters (developed by Total Energie, France) are considered autonomous devices, equipped with an autonomous control logic that leads to a globally co-ordinated behaviour, which is able to maximise the solar energy production and the overall efficiency. Frequency and voltage regulation are performed by the GMC through diesel power gen-set's voltage and speed regulators and a Central Energy Buffer System's (CEBS, developed by A.N.I.T., Italy) with bi-directional power modulation capability. Different control strategies and operating modes are defined to cope with the forecasted system evolution. GMC's tasks include configuration management, control strategies management and battery charging management. The GMC, together with the various components developed for the project, were installed at a pilot plant at CRES (Greece) to be tested and validated. Results and Conclusions: The project indicates a way to transform island grids powered by diesel generators into hybrid ones with the main power contribution coming from distributed PV inverters and ultimately to establish 100% renewable energy electrified, isolated communities. The Grid Master Control System (GMC) goal is to achieve improvements in terms of power availability, frequency and voltage regulation, fuel and maintenance savings, air emission and noise reduction. The distributed PV inverters are not centrally controlled, in order to reduce costs and to increase system simplicity and reliability.