Multi-objective 3-stage wind turbine gearbox (WTG) with tribological constraint

Abstract

A novel multi-objective wind turbine gearbox (WTG) optimization problem is carried out using Non-Dominated Sorting Genetic Algorithm (NSGA-II). Weight of the gearbox and power loss are the two conflicting objective functions set to be minimized. Various design constraints that are related to the mechanical as well as tribological are considered in this study. Three different types of gear tooth involute profiles are considered, namely unmodified, smooth meshing, and high load capacity. These three profiles are tested with different synthetic-based ISO VG PAO (Polyalphaolefin) oils at the rated speed of 20 rpm. The results of WTG are compared with and without tribological constraint by using ISO VG PAO 320, 680, and 1000 oils. Also, the result of one helical gear pair is validated with commercial gear software KISSsoft using ISO VG 680 mineral oil. Pareto fronts obtained from various ISO VG PAO synthetic-based lubricants are compared for all three gear profiles. From the results, PAO 320 oil outperforms than other two grades (PAO 680 and 1000). Further for the chosen model, on comparing with and without tribological constraint, power loss is notably reduced with tribological constraint.