Abstract:
It is well known that an externally driven induction machine can be successfully operated as an induction generator with sustained self excitation when an appropriate value of a capacitor bank is appropriately connected across the terminals of the induction machine. Such an induction machine is called a self-excited induction generator (SEIG). Self-Excitation process in induction generators is a complex physical phenomenon, which has been studied extensively in the past. The interest, in this topic is sustained primarily due to application of self-excited induction generators (SEIG) in isolated power systems. Owing to the changed emphasis on energy problems, the development of suitable low cost isolated power generators, driven by renewable energy sources such as wind, biogas, etc indeed in promising alternative.
The terminal reactive power support in case of isolated generator is required to be adjustable so that the proper amount of reactive power can be supplied under different operating conditions. Consequently, a controllable terminal voltage for the self-excited generator can be obtained through an appropriate control scheme. To fulfill the objective of varying the equivalent capacitance connected to the generator terminal continuously, some power electronic circuits need to be introduced into such a system.
This dissertation work proposes a static compensator based technique in order to provide balanced reactive power operation for the induction generator with the load connected at the stator terminal of the IG. The proposed controller by using current-controlled voltage source inverter (CC-VSI) regulates the IG terminal voltage against .changing load conditions. The scheme doesn't require computations and information regarding rotor speed for calculating the excitation current, there by minimizing the cost of the controller. A simulation model is developed in MATLAB/SIMULINK simulator software to know the performance of the proposed system. This dissertation work carried out with the analysis and performance of SEIG with Current-Controlled Voltage Source Inverter.
