Abstract: Methods and systems for detecting systemwide service issues by using anomaly localization. In an example, a method includes receiving time-series monitoring data for multiple services, the time-series monitoring data including multiple dimensions and an error metric; for the monitoring data from each service, evaluating scopes within the monitoring data based on an objective function for a time-series of the error metric to identify at least one anomalous scope, each scope including at least one dimension and a value for the dimension; based on evaluating the scopes, generating a ranked list of scopes for each service based on objective function scores for the scopes; correlating the ranked lists of scopes across the multiple services to identify a cross-service anomaly; and generating an alert for the services based on the cross-service anomaly, the alert indicating at least one scope as a potential root cause for the cross-service anomaly.

Abstract: A pitch drive system for a wind turbine includes a pitch drive motor, a first position detector, a driver, a second position detector, and a controller. When the blades rotate to a mechanical zero position, a position value detected by the first position detector is a first zero point position value. The driver is operable to store the first zero point position value. When the blades rotate to the mechanical zero position, a position value detected by the second position detector is a second zero point position value. The controller is operable to store the second zero point position value. When a corresponding back up command is received, the first zero point position value stored in the driver is backed up into the controller, and the second zero point position value stored in the controller is backed up into the driver respectively.

Abstract: A pitch drive system for a wind turbine includes a pitch drive motor, a first position detector, a driver, a second position detector, and a controller. When the blades rotate to a mechanical zero position, a position value detected by the first position detector is a first zero point position value. The driver is operable to store the first zero point position value. When the blades rotate to the mechanical zero position, a position value detected by the second position detector is a second zero point position value. The controller is operable to store the second zero point position value. When a corresponding back up command is received, the first zero point position value stored in the driver is backed up into the controller, and the second zero point position value stored in the controller is backed up into the driver respectively.