Factors affect on the UFLS: Experimental results

Under Frequency Load Shedding, UFLS, is the last step and the most extreme in protecting electric power systems from black outs and severe damages. The nature of the load and the system voltage play very important roles in the dynamics of the power system. In the present paper, the frequency variation during overloading and the subsequent load shedding is examined experimentally for a single machine system loaded with loads of different natures (resistive and induction machine).The obtained results demonstrate a considerable change in frequency behavior when using different load models. This may be a significant step in minimizing load to be shed if the load model could be estimated adaptively.