The wind-electric water pumping system consists of a wind turbine with a permanent magnet generator that produces 3-phase variable-voltage, variable-frequency electricity. The system performs efficiently at low winds if the right size compensating capacitance is used. At high winds, when the frequency reaches a certain level (60-85 Hz), the system tends to lose synchronization especially under the gusty wind condition. Most small wind turbines have mechanical furling mechanism to turn the rotor out of the wind and slow down the rotor speed. However, furling generally does not occur until synchronization has been lost, so system efficiency is quite low at high wind speeds. By dynamically connecting a relatively large capacitance and/or resistance in the system, the system will stay synchronized over an extended wind speed range and system efficiency will be increased. Based on this principle, smart controllers for three different sized wind-electric water pumping systems were designed, built and tested by USDA-Agricultural Research Service (ARS) and West Texas A&M University, Alternative Energy Institute (AEI), The systems with this controller stayed on line more time at high winds and pumped more water.
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