Stand alone operation of induction generators driven by unregulated wind or hydro turbines

Abstract

Induction generators are very commonly used in isolated areas to generate electrical energy from nonconventional sources such as wind. Due to the lack of electrical supply in isolated areas, the generator needs to be operated in a stand-alone or self-excited mode.

This report will briefly described the theory background of wind energy and Self Excited Induction Generator (SEIG) and it will discussed both experimental work and theoretical analysis to determine various steady-state performances characteristic of 3-phase self excited induction generator driven by unregulated wind turbine. Mainly in this report explained the procedure of conducting experiment to the three types of configurations which are shunt, short shunt and long shunt.

The selection of shunt capacitor and series capacitor need to be determined first. For each configuration, after the experiment had been conducted, all the experimental results were tabulated and the graph of performance characteristic of various parameters with effect of the load power had been drawn in each configuration section.

Experimental results were then later compared with the theoretical result. From the per phase equivalent circuit of shunt SEIG, a set of non linear equation is obtain using the conventional loop impedance. The torque speed characteristic is also incorporated in the generator equation and these equations are solved using a numerical based routine “fsolve” given in MATLAB. The performance characteristic for regulated wind can also be obtained using theoretical method and the result had been compared with the unregulated speed and it had been found that regulated wind gave good voltage regulation.

This report evaluates the performance characteristics of the generator for the three type possible connections and it concludes that short shunt SEIG is found to be a good option in isolated power generation driven by unregulated wind.