Projeto e implementação de uma fonte de tensão controlada para simulação de defeitos

Abstract

Current power systems are undergoing frequent expansion due to increased consumption of electric power. In these systems, there is a possibility of failures in electrical equipment that lead to voltage disturbances in parts of the assembly. These failures can cause damage to equipment of both the generation, transmission and distribution systems of electric energy, as well as of end consumers. In electrical contactors, severe reductions in amplitude, long periods of life, or critical angles of beginning of sinking may cause the device to shut down. Induction motors can be taken out of service if faults with a duration and amplitude exceeding the operating limits are present. Discharge lamp reactors, during sinking events, exhibit current peaks that increase proportionally with the reduction of the supply voltage. The transformer is the most susceptible equipment to these types of failure. These being the most important devices used in transmission and distribution systems of electric energy. They have a significant impact on losses in public services. Although transformers have a long-life cycle, increased industrial consumption results in more severe operating conditions, including failure situations with reduced efficiency. In this way, implying more maintenance costs and reduction of its life cycle. In this work, it was proposed the use of a controlled voltage source topology to perform 127 V sags in the primary of a 127/220 V single phase transformer with 250 W of power. Two test prototypes were assembled, in which changes were made necessary for the correct operation of the source. There were 6 tests with different durations, in which the correct functioning of the source was observed.