DG optimization for CO2 reduction in islolated grids with rising RES penetration: a simulation study
Résumé
Isolated microgrids, notably those located on islands or off-grid mining sites, are experiencing an increase in the integration of Renewable Energy Sources (RES) to mitigate CO2 emissions and reduce dependency on fossil fuels. Consequently, the role of Diesel Gensets (DGs) in these power systems is transitioning from primary energy producers to backup sources, particularly during instances of RES intermittency that may destabilize the system. This shift in operational dynamics highlights the potential necessity for retrofitting thermal engines to align their performance with emerging constraints.This paper investigates the advantages of adjusting a DG specific fuel consumption curve in a microgrid using a previously developed numerical model, capable of calculating total fuel consumption of grid-connected DGs over a year. These adjustments align DGs’ performance with prevailing operational conditions, by modifying components such as turbocharger wastegate inclusion, modification of turbocharger size, and employing electronic or conventional fuel injection methods. In addition, turbo-lag and engines speed controller’s influence on the grid frequency stability are explored in a power system model in Simulink.The optimal adaptation of a DG’s specific fuel consumption curve depends on the predominant operation of the DG within a specific power system. This study provides a roadmap for achieving fuel reduction while considering grid stability as a constraint, applicable to various operational scenarios. Using the Tahitian power system as a case study, yearly fuel consumption is calculated using the presented numerical model and power demand data obtained from system operators. Various scenarios are compared, and the optimal DG configuration in this application is found to be the addition of a wastegate alongside a smaller turbocharger, accounting for a 3.6% decrease in yearly fuel consumption. This analysis offers insights into the potential benefits of DG modifications, potentially leading to improvements in fuel efficiency within microgrids.
