Abstract:
Variable speed wind turbines generators provide the opportunity to capture more power than fixed speed turbines. However the variable speed machine output can be variable voltage and variable frequency for fluctuating wind speeds. The quality of power output can be improved if adequate controls are incorporated in the systems. The fluctuating wind generator output needs to be controlled. To this effect, one needs to study the dynamic characteristics of the generator system under variable speed. Based on the dynamic performance of the system, better controls can be designed. The variable speed generators can create voltage and frequency fluctuations and power surges in a weak network. The effect of the commonly used control techniques like converter/inverters and its control on the quality electricity obtained with reduced harmonics are discussed in this dissertation. The fabrication of the grid connected variable speed constant frequency (VSCF) power conversion scheme has been done to obtain the fixed output voltage and frequency irrespective of the input. An algorithm of tracking the peak power in a wind energy in a wind energy conversion system has been discussed which is independent of the turbine parameters and air density. The algorithm searches for the peak power by varying the speed in the desired direction. The peak power points in the P-co Curve corresponds to dp/dc =0. This fact is made use of in the optimum point search algorithm.
