Direct-drive permanent magnet synchronous generators (DD-PMSGs) have been widely adopted in wind power generation systems owing to their distinctive advantages, including direct-drive operation, high power density, and superior energy conversion efficiency. However, the high power density of the generator inevitably leads to heat generation issues, which affect the reliability of the generator. To address the thermal issues in the 4.5 MW direct-drive permanent magnet synchronous generator (DD-PMSG), this paper proposes a novel forced air-cooling ventilation system. Through comprehensive computational fluid dynamics (CFD) simulations and fundamental thermodynamic analysis, the cooling performance is systematically evaluated to determine the optimal width of the stator ventilation ducts. Furthermore, based on the temperature distribution of the stator and rotor, three optimization schemes for non-uniform core segments are proposed. By comparing the ventilation cooling performance under three structural schemes, the optimal structural scheme is provided for the generator. Finally, the feasibility of the heat dissipation scheme and the accuracy of the simulation calculations are verified by fabricating a prototype and setting up an experimental platform. The above conclusions and research results can provide some reference for the design of the core ventilation ducts structure of subsequent wind turbines.

Electromagnetic separators are widely used in new energy battery purification, resource recycling, and mineral processing. However, coil heating can cause a decline in separation performance and damage to coil insulation. To ensure the stable operation of electromagnetic separators, cooling plates are employed to effectively mitigate temperature rise. To explore a high-performance and economical cooling method, this paper employs CFD finite element analysis for the structural optimization of cooling plates. First, the paper investigates the flow heat characteristics of S-shaped cooling plates. Numerical simulations are performed to analyze the variation of fluid characteristics with different numbers of water channels. Regression equations linking structural parameters to performance indicators are derived, and the optimal channel number and hydraulic diameter are determined. Furthermore, to enhance heat transfer efficiency, an innovative semicircular groove structure is introduced on the cooling plate walls. An optimization strategy based on a genetic algorithm is developed to determine the optimal groove parameters. A simulation shows that the optimized cooling plate reduces coil temperature by 12.63 °C with a decrease of 15.31% compared with the original design. Finally, a prototype with optimized parameters is manufactured after the experimental results of the two test points and the simulation results reveal errors of 0.26% and 0.96%, respectively. The experimental results align well with the simulations, confirming the reliability of the experimental results and the feasibility of the optimization strategy, and providing a reference for future cooling plate designs.