Design Considerations and Many-Objective Optimization of Synchronous Condenser Used for New Energy Power System Based on Electromagnetic-Thermal Constraints

This article investigates the design considerations of air-cooled synchronous condensers (ACSCs) in new energy power systems and proposes a many-objective optimization method combining ensemble surrogate model (ESM) with nondominated sorting genetic algorithm (NSGA)-III. The key lies in designing and optimizing the ACSC from the perspectives of electromagnetic and thermal fields to simultaneously achieve satisfactory transient parameters and thermal behaviors. First, an equivalent model considering eddy current of the ACSC is established, and the direct-axis reactance is determined using the phased amendment method. Second, a coupled model integrating the global ventilation network and local fluid-thermal field of the ACSC is developed. The results from the former were applied as boundary conditions for the latter. Subsequently, the effects of critical geometric sizes on reactance, time constants, and winding temperatures are analyzed, revealing conflicting relationships among key parameters. To rapidly and accurately determine optimal dimensions, an ESM and NSGA-III-based many-objective optimization framework is proposed and implemented, achieving a balanced compromise among optimization objectives. Finally, experimental testing on a 300 MVar ACSC validates the effectiveness of the models and optimization method.