Modeling and Suppression of Reactive Power in Parallel Hybrid Excitation Machine Considering Voltage Harmonics

The parallel hybrid excitation machine (PHEM) combines a field modulation machine part (FMMP) and a permanent magnet machine part (PMMP), providing high power density and adjustable flux control. However, the reactive power exchange between the FMMP and PMMP under load conditions limits the output capability of the PHEM. This study conducts an in-depth analysis of the reactive power of the two machines under load, comparing the output performance of the generators when the FMMP adopts Y-connection and Δ-connection topologies. First, the topological structures of both winding configurations are explained, and design schemes for the FMMP and PMMP are provided based on short-circuit current constraints. Then, through harmonic analysis of voltage and current, a power calculation model that considers voltage harmonics is established. Finally, a detailed comparison is made of the active and reactive power generation in both topologies for the FMMP and PMMP. A prototype was developed, and the experimental results were consistent with the simulation. The results indicate that while both winding configurations perform similarly under light load, the Δ-connection can effectively suppress reactive power and enhances output capacity.