An electronic controller has been developed for a wind turbine which uses a passive
pitching mechanism and a permanent magnet generator. The turbine rotor is a 3
bladed, down wind horizontal axis design with a diameter of 3.4m. The machine,
manufactured by Proven Engineering Ltd., produces 2.2kW at a wind speed of
12m/ s and a rotor speed of 30Orpm.
Passive regulation is achieved through a variation of blade pitch controlled by
balancing the aerodynamic, centrifugal and spring forces acting on each blade.
A production machine has been instrumented and laboratory and field test data
collected; from this data a mathematical model has been derived. A power electronic
interface (DC-DC booster) was designed and built to transform the generator
voltage to a fixed DC voltage. A controlled load is used together with feedback
to the booster to set an appropriate load resistance according to operating conditions.
Current demand from the generator (used in the control) is derived either from the
difference between the rotor speed and a reference speed, or directly as a function
of the rotor speed (feed-forward control).
This thesis deals with the design and testing of the 3 compensators which govern
the wind turbine control using both simulated and measured results. The overall
objective of the controller is to maximise the energy yield from the wind turbine,
subject to realistic constraints imposed by the power electronic design in the
context of this particular design.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.