Mathematical Modelling of the Synchronization Process in Autonomous Power Supply System with Renewable Energy Sources

Current global interest in implementation of renewable energy sources in autonomous power systems leads to increasing concerns regarding stability. These systems are expected to be functioning in an islanded mode, therefore it is of utmost importance to consider related stability problems. One particular case is synchronization or paralleling of the generating units. In a big power grid one instance of generator synchronization with the system is not likely to cause any significant disturbances as the power system effectively dampens the oscillations which may occur during the transient. In a weak grid, however, any synchronization event is threatening to impact a normal operating state, if not conducted properly. The aim of this paper is to assess applicable synchronization methods. For this matter a test model for islanded power system was designed in Matlab/Simulink in order to simulate the process of synchronization between two synchronous generators, driven by diesel engines.