Design, Development and Testing of a Prototype Extendable Blade Wind Turbine
Abstract
The wind energy industry has grown fast over the past decades. One critical part in maximizing and regulating energy production in any wind turbine is the control system. Typical wind turbines perform variable speed and variable pitch control strategy, but the concept of using an extendable blade wind turbine as an alternative actuation is not fully explored. This thesis will explore the design and development of an extendable blade wind turbine along with experimental wind tunnel testing of the prototype operating in a power regulation region. Extendable blade wind turbines add a different degree of freedom to the control strategy. Through the use of a blade extending mechanism, swept area of turbine blades could be adjusted to vary energy capture and mechanical loading on the system. The turbine blades were designed with Blade Element Momentum Theory and they were constructed with 3D printed plastic and a retractable mechanism. A direct current gear motor in the turbine hub is used to control the blade extending and retracting mechanism in a feedback manner wirelessly. A laptop, micro-controllers and sensors are used for measuring the generated power, rotational speed and the blade position. The measured power is fed back to the system and control signals are sent to the motor which extends and retracts the turbine blades. Initial testing showed that the effect of varying blade length has a significant impact on generated power. Closed loop feedback control shows effective power regulation and disturbance rejection of wind speed variations near a selected rated power level for the machine. This regulation is achieved through extending and retracting the blade only based on feedback power measurements. Variations of proportional-integral-derivative controllers were used to track a constant reference under those wind conditions and the result of different controller gains were analyzed using one-way Analysis of Variance. The integral gain was found to be statistically more sensitive as compared to the proportional and differential gains. Thus a proportional-integral control is recommended for operation of this type of system.
Description
Keywords
Engineering--Mechanical
Citation
Cheung, H. F. (2017). Design, Development and Testing of a Prototype Extendable Blade Wind Turbine (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25579