Load Frequency Control Based on the Control Allocation Approach for Isolated Microgrid

DE MARCO, FERNANDO; ZUMOFFEN, DAVID; TIELLI, MATIAS; RULLO, PABLO GABRIEL; LUPPI, PATRICIO

Foz Iguazu

Simposio; .2do SIMPOSIO IBEROAMERICANO en Microrredes Inteligentes con Integración de Energı́as Renovables - SIMIIER 2018.; 2018

CYTED

This paper describes a load frequency control (LFC) scheme based on the control allocation (CA) approach that distributes the load sharing effort among the controlled generating units according to the individual spinning reserves and loading and deloading rates. The CA module can explicity handle constraints on inputs such as saturation and rates limits, and additional control objectives (e.g., to penalize the actuators control energy). At the same time, CA has the potential to provide fault tolerance (e.g. unit tripping) and redistribute the control effort over the available units, and without considering a control structure reconfiguration. The proposed architecture involves two levels: (i) a high level structure implemented with a conventional PI controller, (ii) a CA module based on a weighted least-squares formulation which utilizes an active set method algorithm. The simulation results of a study case show the robust performance of the proposed LFC scheme, which is suitable for microgrids and islanded power systems with generating units unevenly dispatched with different ramping rates, and renewable energy sources with irregular power supply.