Economic Analysis of a Fractional Frequency Offshore Wind Power System Utilizing PMSG for Direct-Drive Turbines Without Terminal Converters

This paper introduces the topology and working principles of a fractional frequency offshore wind power system based on permanent magnet synchronous generator for wind turbines with terminal converters. It thoroughly investigates the methods for determining the center frequency and frequency variation range on the low-frequency side of the system. An economic analysis model for the offshore wind power system is established, which includes initial investment, annual loss costs, and annual maintenance costs. Based on the developed economic analysis model and specific examples, the total present value of costs for offshore wind power systems transmitted via four different transmission methods is analyzed and compared, validating the feasibility and economic viability of the proposed topology.