Modeling and Effect of Core Loss in AC Three-Phase Self-excited Generators Used in Wind Energy Applications

Green renewable energy sources have been introduced as alternatives to avoid the environmental impact of the hazardous waste of conventional power generation. One of these remarkable exploited green sources is wind energy. Self-Excited AC Generators, namely, three-phase Self-Excited Induction (SEIG) and Reluctance (SERG), generators are used to convert wind power to electric power. Extensive research studies have been carried out on the analyses of dynamic, transient, as well as steady-state performance of these generators. In most of these studies, core losses were neglected. However, different methods have been attempted to consider the core loss by adding resistance to the model of the generators. The values of this resistance are taken as either; (i) fixed, (ii) linearly proportional to the magnetizing reactances (Xm or Xd), or (iii) variable as a polynomial function of Xm (or Xd). This chapter presents a comparative study to assess the above-mentioned three methods under different operating conditions of (SEIG) and (SERG) generators. The effect of neglecting the core loss on the analysis are studied. The method no. (iii) above is used as a reference to evaluate the errors in the other methods. The generator performance resulted from the three methods is shown and compared. Experimental verifications are included to illustrate the most accurate method to account for core loss in generator analysis.