Wind turbine backup power supply monitoring

摘要

A method for testing a condition of a back-up power supply of an axis in a wind turbine, the back-up power supply having an associated voltage, the method comprising: electrically isolating an axis of the wind turbine from a grid power supply; Discharging the backup power supply to a first predefined current for a first period of time; Measuring a first value of the voltage; Operating the axis with a backup power supply until the voltage reaches a predefined second value; Discharging the backup power supply to a second predefined current for a second period of time; Measuring a third value of the voltage; And calculating a parameter-parameter based on at least the first and third values, the characteristic of the state of the back-up power supply.