Reliability Analysis of Sub Assemblies for Wind Turbine at High Uncertain Wind

Abstract

The wind energy plays a vital role in the world renewable energy scenario. The modern wind turbine system has a complex and repairable components due to sophistication and centralized control. The failure characteristics of the onshore wind turbines depend on the terrain conditions. In the main mountain pass and hill area, there is a heavy uncertainty in the wind that is due to the frequent change in the direction of wind and the change in the velocity. It causes a rapid failure in the individual sub assemblies. There is a substantial need for improving the reliability in the stages of design, manufacturing, operation and maintenance. Normally the infant mortality failures are more in the onshore wind turbine and the failure rate is constant during normal operating period. It is a surprise that the failure rate has rapidly increased during normal operating period of the wind turbines placed exactly in the mountain pass and hilly area due to the high uncertainty in the wind. This paper deals with reliability analysis of major components of wind turbine system and its sub system such as rotor system, gear box, brake system, generator, hydraulic system and yaw system. This paper also investigates the reliability of wind turbines and its sub assemblies placed at Aramboly pass in India by using Weibull software as reliability tool for a grid connected 250 kW wind turbine. This analysis yields some surprising results about some sub assembly like yaw system, brake system and generator which are most unreliable.