Fault detection device for wind power generator and means of judgment thereof

A method of fault detection using a plurality of detectors through entering values measured by the detectors into an apparatus configured to perform fault detection steps for a wind power generator, comprising the steps:

• step a:
• using a plurality of detectors to acquire measured values from the wind power generator and entering into the apparatus measured values including vane rotational speed measured by a second detector comprising a vane rotation detector, three phase mean voltage and power measured by a third detector comprising a power detector, vane pitch angle measured by a first detector comprising an encoder, and wind speed measured by a fourth detector comprising a wind speed detector;
• step b:
• determining if the measured vane rotational speed value by the second detector is equal to the actual vane rotational speed value, and the measured three phase mean voltage value by the third detector is equal to actual three phase mean voltage value, if the result is negative, the process goes to step c, if the result is affirmative, the process goes to step d;
• step c:
• the measured vane rotational speed value is determined to be faulty and the measured three phase mean voltage value is determined to be faulty and the fault detection process is terminated for fault correction;
• step d:
• determining if the measured power value by the third detector is equal to actual power value by checking if a relative error is less than 5% of actual power value and:
• if it is, determining that the measured power value is equal to actual power value and proceeding to step f;
• or, if it is not, proceeding to step e;
• step e:
• determining the measured power value error, if the relative error is equal or more than 5%, the result is to be determined faulty, and the process is terminated for fault correction;
• step f:
• determining if the measured vane rotational speed value is normal and if the measured three phase mean voltage value is normal;
• step g:
• determining if actual power coefficient (Cp) vs. actual tip speed ratio (λ) vs. actual vane pitch angle value (β) is satisfied with equations below, and if the result is negative, it goes to step i;
• if the result is affirmative, it goes to step h;
• wherein the measured vane pitch angle value (βm) is substituted into the equation below to
• obtain a calculated tip speed ratio (λc), λ=0.000435 β2−0.09587 β+4.955, and
• wherein a calculated power coefficient (Cp-c) is obtained by equation
• Cp =0.00792 λ3 −0.002822 λ2−0.0042λ;
• and
• wherein √{square root over ((λm−λc)2+(Cp-m−Cp-c)2)}{square root over ((λm−λc)2+(Cp-m−Cp-c)2)}≦0.06;
• wherein λ is actual tip speed ratio, λc is calculated tip speed ratio, λm is measured tip speed ratio, Cp is an actual power coefficient, Cp-c is a calculated power coefficient, and Cp-m is a measured power coefficient;
• step h:
• determining if the measured power value, the measured vane pitch angle value, and the measured wind speed value are normal and the fault detection process is completed without any fault being detected;
• step i:
• determining if the measured vane pitch angle value (βm) by the first detector is equal to actual vane pitch angle value (β), if the result is negative, it goes to step j, and it goes to step k otherwise;
• step j:
• it is confirmed that the measured vane pitch angle value (βm) is determined to be faulty, and the fault detection process is terminated for fault correction;
• step k:
• it is confirmed that the measured wind speed value is determined to be faulty, and the fault detection process is terminated for fault correction.