Performance Analysis of Series and Parallel Capacitor Connections of a Synchronous Reluctance Generator for Wind Energy Conversion System

This study examines the optimization of synchronous reluctance generators (SynRGs) for wind energy conversion systems (WECS), focusing on the comparative performance of series and parallel capacitor connections. The purpose is to address persistent challenges in voltage regulation, reactive power compensation, and energy efficiency that limit SynRG adoption in renewable energy applications. Existing systems frequently experience poor voltage regulation, reaching up to 12.8% under series compensation, and suboptimal efficiency of only 88.3% at full load. To resolve these issues, the research employs d–q axis modeling, transient analysis, and multi-objective optimization using the Non-Dominated Sorting Genetic Algorithm II (NSGA-II). Simulation and analytical results reveal that parallel capacitor configurations significantly outperform series arrangements, improving voltage regulation by 8.1 percentage points (reduced to 4.7% at 100A load) and increasing efficiency by 2.6 percentage points (achieving 90.9% at full load). Reactive power analysis shows that series capacitors provide a variable output up to 63.7 kVAR at 100A, while parallel capacitors deliver a stable 15.1 kVAR, with crossover occurring at 38.6A. The optimal sizing of capacitors is determined as 21.2 μF/kVAR, with a 100 μF capacitor yielding 30.2 kVAR of compensation. Based on these findings, three policy guidelines are proposed: (1) prioritize parallel capacitor configurations for applications requiring 90% efficiency, (2) adopt series compensation selectively for heavy inductive loads exceeding 40A where reactive power demand surpasses 15 kVAR, and (3) apply the 21.2 μF/kVAR rule for capacitor sizing to balance performance and cost-effectiveness. These results provide practical insights for engineers and policymakers aiming to enhance the reliability, efficiency, and sustainability of wind energy systems using SynRG technology.