A inverted tower accident happened on account of wind turbine′s speed loss in wind power plant

the direct reason for accident was without closing the DC power switch for urgent variable pitch after maintaining and eliminating defect of wind turbine. This led to the failure of urgent return of blade

wind turbine′s speed loss and losing control of the wind turbine.The indirect reason of accident was that wind turbine could still start normally when urgent variable pitch power didn′t put into operation

violation operation by maintainer

lack of management about eliminating defect

low technical level of facility operators and maintainers. To prevent this accident happening again

the corresponding preventive measures are put forword according to the fault cause.