The invention provides a method for monitoring the state of a gearbox of a
wind power generation set. The method includes the following steps of: collecting historical data of a
wind power generation set
SCADA system, screening out the active power,
wind speed, cabin temperature, principle shaft rotation speed and gearbox
oil temperature of the set under the healthy operation condition, and establishing a standard expert
database; optimizing the
penalty coefficient and the nuclear parameter of a
least squares support vector regression machine by using a
gravitational search algorithm, and establishing a gearbox
oil temperature mapping model under the healthy operation condition by taking the active power,
wind speed, cabin temperature, principle shaft rotation speed in the expert
database as inputs and the gearbox
oil temperature as an output and based on the optimized vector
machine model; monitoring the gearbox of the
wind power generation set in real time by using the mapping model, inputting the actually measured values of the active power,
wind speed, cabin temperature and principle shaft rotation speed to obtain the predicted value of the gearbox oil temperature, defining the quotient of the predicted value of the oil temperature and the actually measured value as a judging index, and judging that a failure occurs in the gearbox of the
wind power generation set and giving an alarm, if the statistical property of the judging index is abnormal. The method can be widely applied to early warning of the gearbox of the
wind power generation set.