Condition monitoring system and wind power generation system using the same

A condition monitoring system for monitoring a condition of equipment configuring a wind turbine, the wind turbine including a nacelle rotatably supported on

• a top of a tower, the condition monitoring system comprising:
• a first detector configured to detect the condition of the equipment;
• a monitor device configured to generate a diagnosis parameter based on a detection result of the first detector;
• a controller configured to diagnose a failure of the equipment based on the diagnosis parameter;
• and
• a second detector configured to detect a rotation speed of the nacelle,
• the controller being configured to diagnose whether the equipment has a failure by correcting the diagnosis parameter using a relationship between a dimensionless diagnosis parameter, which is obtained by dividing the diagnosis parameter by a diagnosis parameter obtained during non-rotation of the nacelle, and a dimensionless rotation speed of the nacelle, which is obtained by dividing the rotation speed of the nacelle calculated based on a detection result of the second detector by a maximum speed thereof, and comparing the corrected diagnosis parameter with a predetermined threshold value.