Abstract: This paper presents an Offshore Wind Farms with Low Frequency AC Transmission Connection to the Main Grid. In present years the electricity produced from wind has grown rapidly. Offshore wind farm is currently seen as a promising solution to satisfy the growing demand for renewable energy source. The main reasons for the rapid development of offshore wind farms includes much better wind resources and smaller environmental impact. The possible solutions for transmitting power from wind farms are HVAC, Line commutated HVDC and Voltage source based HVDC (VSC-HVDC). The limitations of both the HVAC and HVDC technologies when applied for far offshore wind farm connection Low Frequency AC (LFAC) transmission system is a new and alternating solution. In LFAC systems, an intermediate-frequency level is used, which is created using a cycloconverter that lowers the grid frequency to a smaller value, typically to one-third its value. For interconnecting the offshore wind farms with Low Frequency AC (LFAC) transmission system for improving the transmission capability and distance compared to the conventional AC solution at the nominal frequency, e.g.50Hz or 60Hz. The dc collecting system with series connected wind turbines are used at the offshore to reduce the cabling requirement. The wind power plant collection system is dc based, and connects to the LFAC transmission line with a 48-pulse converter. The output waveforms are observed in MATLAB.
Keywords: Power transmission, wind energy, thyristor converters, low frequency AC (LFAC), cycloconverter.