Analyzing The Effect of Motor Loads and Introducing a Method for Selection of Electric Generator Power Rating

摘要

Dynamic operating conditions of electric generators are very critical case for smaller and isolated electrical power grids. Induction motors play an effective role in industries. At starting an induction motor, it draws high value of current from the power system supply. This causes a voltage and frequency dips in the electric system, and create problems to the supply generator and its connected loads. As compared to a utility, a stand-alone electric generator is a limited electric power source, from the rotating engine, and supply output power. Therefore, a generator power rating must be enough to start and run its connected motor loads in a convenient way. This paper will analyze the dynamic behavior of a stand-alone generator supplying induction motor, during start-up. In addition, the paper introduces a technique to select the most suitable generator power rating supplying certain electric loads taking in consideration the effect of ambient operating temperature, loads power factor, non-linear loads harmonics, and motor loads combined together. The study ensures safe and reliable operation of the supply generator.