Analysis and detection of a wind system failure in a micro-grid

This paper presents the performance of a wind power system under failures in the lubricant system, and a procedure is proposed to detect the failure. According to the fact that the friction torque caused by the lubricant system, failure makes the maximum power point (MPP) of the wind system to be smaller than that of normal operation; for MPP tracking operations, the difference between actual and simulated (estimated) output power of the wind system is an indicator for the lubricant system failure. However, for non-MPP tracking operations, in which the demanded power is small enough to be satisfied by the failed wind system, the above indicator cannot be used to detect the lubricant system failure. In this case, the predetermined angular shaft speed ratio is used to detect the lubricant system failure. Moreover, the converter failure is considered in this paper, and a model-based fault detection filter is designed to detect the DC/DC converter failure in a wind system. The proposed detection filter consists of an observer combined with a residual signal generator, where the driving torque is assumed as an unknown bounded input in the proposed failure detection scheme. Numerical simulation results support the proposed detection procedures. Published by AIP Publishing.