An overspeed protection system for a wind turbine having a hub and at least one rotor blade mounted to the hub includes a rotation sensor adapted for measuring a rotor speed of said wind turbine; a comparator connected to the rotation sensor and adapted for comparing the measured rotor speed with a predetermined threshold value of the rotor speed wherein the comparator outputs a signal indicative of the comparison; and an auxiliary pitch drive controller connected to the comparator and adapted to receive the signal indicative of the comparison, the auxiliary pitch drive controller being further adapted for controlling a pitch drive unit of the wind turbine independently of a main turbine controller and, if the threshold value is exceeded, to adjust a pitch angle of the rotor blade of the wind turbine so that aerodynamic braking of the wind turbine is effected.
[pdf] The paper proposes a novel planning approach for optimal sizing of standalone photovoltaic-wind-diesel-battery power supply for mobile telephony base stations. The approach is based on integration of a compr.
[pdf] The had almost two (GW) of capacity at the end of 2010, but installed less than 10 megawatts (MW) in 2011 due to the being reduced by 25%, after installing almost 1,500 MW the year before. Installations increased to 109 MW in 2012. In 2014, no new installations were reported. The Czech Republic receives an average of about 1,670 hours of sunshine per year. 1 In the Czech Republic, the average annual energy yield for solar photovoltaic (PV) systems is approximately 1,000 to 1,200 kWh per kWp installed. 2
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