Detection of mechanical unbalanced faults in wind turbines by using electrical measurements

Abstract

Wind power generation is the fastest growing energy source among the new power generation sources in the world because of less atmospheric pollution. The increasing production capacity needs online condition monitoring system to improve wind turbine reliability and performance and reduce wind turbine downtime, operating and maintenance costs. Maintenance cost and downtime period of offshore wind turbines is getting higher because of remote location and difficult to access for fault repair. Vibration measurement and lubrication oil analysis are used in wind turbine condition monitoring systems. However, initial cost of these systems are higher and they do not provide a complete solution to the wind turbine condition monitoring system problem. They also can not detect electrical faults and abnormal condition occuring in the wind turbine generator and electrical systems. To reduce wind turbine monitoring system problem, a new mechanical unbalance detection algorithm based on electrical parameter measurement has been introduced in this study. The proposed condition monitoring system measures three phase current and voltage measurement and calculates instantaneous generator output power. In the mechanical unbalanced condition additional frequence components, which is the basis of the proposed algorithm, according to the generator pole number appear in the instantaneous power.