Multidisciplinary design optimization of a direct-drive PMSG including the power converter cost and losses

This paper presents the multidisciplinary design optimization (MDO) of a WECS permanent magnet synchronous generator (PMSG). The MDO is applied to a medium power WECS (55 kW) with the objective of reducing its cost. The WECS model includes, in addition to the model of the PMSG, cost and losses models of the power converter. The wind turbine cost is not included in the model. Although numerous papers discuss the optimal design of the PMSG, few examine the influence of power converter cost and losses in WECS total cost. The optimal design methodology proposed here produced three different WECS, each to a different phase angle of the current. The results show that the current phase angle affects the costs of the PMSG and of the power converter differently. The result of the optimization allowed to define the phase angle of the current which minimizes the total cost of the WECS.