Thesis (MScEng)--Stellenbosch University, 2013. / Wind energy has proven to be a viable source of clean energy, and the worldwide
demand is growing rapidly. Variable speed topologies, with synchronous generators
and full-scale converters, are becoming more popular, and the e ective control of these
systems is a current trend in wind energy research.
The purpose of this study is the modelling, design, simulation and implementation
of a small-scale, variable speed wind energy conversion system, incorporating the position
sensorless direct torque control with space vector modulation, of a permanent
magnet synchronous generator, including an RLC converter lter. Another aim is the
development of a gain scheduling algorithm that facilitates the high level control of the
system.
Mathematical models of the combined lter-generator model, in the stationary and
rotating reference frames, are presented and discussed, from which equivalent approximate
transfer functions are derived for the design of the controller gains.
The design of the controller gains, RLC lter components, gain scheduling concept
and maximum power point tracking controller are presented. It is discovered that the
RLC lter damping resistance has a signi cant e ect on the resonance frequency of the
system.
The system is simulated dynamically in both Simulink and the VHDL-AMS programming
language. Additionally, the maximum power point tracking controller is
simulated in the VHDL-AMS simulation, including a wind turbine simulator. The
simulation results demonstrate good dynamic performance, as well as the variable
speed operation of the system.
The practical results of torque and speed controllers show satisfactory performance,
and correlate well with simulated results. The detailed gain scheduling algorithm is
presented and discussed. A nal test of the complete system yields satisfactory practical
results, and con rms that the objectives of this thesis have been reached.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/80242 |
| Date | 03 1900 |
| Creators | Bouwer, Pieter |
| Contributors | Kamper, M. J., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 139 p. : ill. |
| Rights | Stellenbosch University |
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