QRDc has developed a non-rotating wind power generation system that has minimum maintenance cost. It has no bearing, no lubrication, no shaft, no rotating element.

Abstract

Significantly improved long-term reliability of wind turbines has become critical as they increase their penetration into the national and international electrical power base. The major subsystems in wind turbine systems include blades, gearboxes, generators, power transferring shafts, bearings, and towers. Advanced acoustic and vibration modelling techniques and monitoring systems have been employed to effectively predict and monitor the health of wind turbines. The goal is, in addition to having system capability for determining structural condition, to reduce unscheduled outages, and to predict maintenance cycles in order to avoid failures. By better understanding the root causes of noise and vibration, one could significantly boost performance, maintainability, and reliability while reducing downtime and catastrophic failures of wind turbines that are becoming crucial to meeting the global renewable energy goals.

The main root causes of wind turbine noise, wear, damage, and failure is excessive vibration. In particular, excess noise has become a growing problem for farmers and those living near wind farms. In this paper, the top six of the most important causes of rotating machines and turbines failures due to excess noise/vibration are discussed. Such root causes are blade mistuning, misalignment, imbalance, resonance, fastener looseness, and bearing damages and defects. Three of these root causes have been responsible for over 80% of excess vibration and noise, and machinery wear, failure, and downtime. Wind turbine-generator systems are no exception and follow the same failure modes.

We approached the wind farm noise in manner similar to our work in the mining and processing industry. In the latter case we replaced the root causes of excess noise in vibratory machines (i.e., 200 lbs eccentric electrical motors) with 1 lb PZT-based actuators that practically make no noise. Using the same methodology, we have managed to fully mitigate the excess vibration and noise from the conventional wind farms by eliminating the root causes of vibrations, namely turbine blades, gearboxes, generators, power transferring shafts, bearings at the top of towers.