Performance of the CEGB Howden-WTG wind turbine at Carmarthen Bay Power Station

A 24 m 3-bladed wind turbine was installed for the CEGB at Carmarthen Bay Power Station in 1982. The machine had a high-solidity slow-running rotor which was stall regulated at about 300 kW. Adjustable blade tips were provided for control purposes. Monitoring of the performance of the machine was undertaken using sensors on the wind turbine, in conjunction with anemometers on masts 50 m from the rotor. The power/wind-speed curve was found to be consistent with predicted values, although the power was limited to 200 kW during most of the operating period. This limitation was imposed to restrict large peak torques produced by a poorly damped drive-train torsional mode. Analysis of the aerodynamic design showed that the energy yield at the chosen site could have been improved with a different rotational speed. A theoretical modelling of the drive train yielded a power spectrum generally in line with measurements and clearly showed that the lightly damped first torsional mode was the source of most of the energy in the power swings.