Performance of an autonomous diesel-wind turbine power system

The feasibility of installing a 2.5 MW wind farm within an isolated power system in Western Australia is examined. This network is at present being supplied by several diesel generators. The main design consideration is the dynamic interaction between these generators and the wind turbines. The paper begins with a discussion of the results of field tests carried out on the diesel units. The performance of these alternators under disturbance conditions is assessed and the test results are used to derive improved computer representations for the generators. The proposed wind farm employs induction generators. The behaviour of the hybrid diesel-wind turbine power system is then studied by assessing the effect of normal variations in the wind mechanical power on system frequency and voltages. It shows that the wind turbines would degrade the quality of the electrical supply by causing unacceptably large voltage and frequency excursions. Thus there is a need for fast automated control actions if the full potential of the wind farm is to be exploited. Consideration of other disturbance types also leads to this conclusion. The application of a static var compensator and upgrade of the diesel generator control systems are the two options examined. It is shown that these methods can alleviate the design problem satisfactorily.