Adjusting The Alternator Voltage By Changing The Angle Of Downhole Turbine Wing
Publication Date: 2005-Jun-30
The IP.com Prior Art Database
The angle of the downhole turbine wings can be adjusted by connecting the wing tips to an actuator in the axis of the turbine. Alternatively the actuator could be located in the stator. In prior art the same method is used to create low frequency sound as an alternative option to commonly used loud speaker. The same method is used for active noise cancelation. Novel idea is to use the same system to change the turbine speed of a downhole turbine. Usually downhole tools must operate over a wide range of flow rates. The electrical power is generated by a turbine driving an alterantor. The alternator voltage is therefore proportional dependent to the flow rate. As a result the flow range of a downhole tool is often limited by the voltage range of the electrical power regulation. By changing the wing angles of the turbine the turbine speed can be varied, allowing to decrease the voltage range of the power electronics. In return, this will allow increasing the operational flow rate range of the downhole tool. Another feature of the wing angle adjustment is to actively change the cross section area for foreign bodies in the mud stream, decreasing the risk of turbine plugging.