Enhancing Optimal Automatic Generation Control in a Multi-Area Power System with Diverse Energy Resources

New power system control methodologies have recently been proposed that combine economic dispatch (ED) and automatic generation control (AGC) in order to maintain economic operation when the generation mix incorporates a high penetration of renewable energy sources (RESs). The theoretical framework that under-pins these techniques assumes that an aggregated control area model (CA) can be defined, assuming that the dynamic response of the entire control area is dominated by a single energy source, typically a steam-turbine generator. This paper investigates a combined AGC and ED control methodology for a power system with control areas containing multiple hybrid energy resources that cannot be simply aggregated into a single equivalent source. An optimization approach is then used to develop a control law and parameter design algorithm for each energy source, which accounts for their individual dynamics while aggregating the generators output to match with the target output of the CA. The performance of the proposed AGC and ED controller is demonstrated using simulation studies of an interconnected power system, conducted within the DIgSILENT power factory platform. This model incorporates non-linear network system dynamics and control loops within automatic voltage regulators (AVRs) and power system stabilizers (PSSs). The study results indicate that the proposed AGC optimal control strategy offers superior performance compared to traditional and recently published economic AGC strategies, particularly when the generation mix includes both dispacthable conventional sources and a high penetration of non-dispatchable or semidispatchable sources such as wind.