Optimum frequency-based design of off-shore wind power plant (OWPP)

The paper presents a novel idea of optimum frequency-based design of off-shore wind power plant (OWPP). In the literature a new transmission system i.e. Fractional Frequency transmission System (FFTS) is proposed as an economic alternative to High Voltage AC (HVAC) and High Voltage DC (HVDC) for power transmission from Off-shore Wind Farm (OWF) to on-shore grid. In the FFTS power transmission is done at a fractional frequency i.e. 1/3^rd of conventional frequency (50Hz). This fractional frequency (50/3Hz) seems to be a compromised frequency rather than an economical frequency. As the power transmission network cost is frequency-dependentthere may lay some economical frequency in therange 1-50Hz. The paper presents a methodology to determine the most economical frequency by optimizing frequency-based cost model of the system using Genetic Algorithm. As a case study for an OWPP of 160MW and varying off-shore distance of 50km, 100km, 150km and 200km the optimal frequencies are obtained as 57Hz, 35Hz, 23Hz and 17Hz resp... Hence it is concluded that the work presented in the paper results in significant cost reduction of the electric system.