Local hierarchical control for industrial microgrids with improved frequency regulation

Abstract

Local control strategies that operate without relying on communication systems enhance flexibility and reliability of AC industrial microgrids. Based on a previous work in which a secondary switched control was proposed, this paper presents a complementary strategy to improve the frequency regulation by reducing the maximum error. To this end, a dynamic-gain droop method driven by a time protocol is used. With this proposal, the maximum frequency error is effectively reduced without relying on complex techniques and maintaining the simplicity of the basis strategy and the non-use of communications. Experimental results obtained on a laboratory microgrid are presented to validate the performance of the proposed complementary control strategy.