METHOD, SYSTEM AND DEVICE FOR MONITORING ELECTRIC ENERGY WITH HARMONICS AND INTER-HARMONICS FOR PREDICTING FAULTS IN LOW-VOLTAGE SUBSTATIONS.

摘要

The invention refers to the method and system for monitoring electric energy with harmonics and inter-harmonics for predicting the faults in low-voltage substations, also including devices for the detection in situ of faults in the substation secondary. With the purpose of detecting incipient faults in electric network installations by electronic devices and inductive sensors coupled to said installations, a diagnosis and an anticipated detection of faults is performed before the faults might be catastrophic and the installation, electric supply and safety and integrity of the users might be at risk. The measurement of harmonics and inter-harmonics in interconnected electric systems is carried out with the purpose of associating the quality of the electric energy. This system performs an analysis of the effects caused to a power system and interconnected elements, such as: electric substations, transmission lines and induction machines, and it is based on the standards established by the IEEE, which govern the harmonic and inter-harmonic content. The detection system is non-intrusive and may be used in recent or current equipment, without performing major modifications to the installation; the system includes sensors for monitoring the conditions of the electric installation, a device for conditioning and treating the electric signals, a wireless transmission device for remotely sending the data to the master hub, which is simultaneously transmitted to a master station, where a server along with a PC is located; a method specifically designed to interpret the data and manage the information is useful for analyzing and detecting the state of the electronic equipment, being able to anticipate possible faults by diagnosing the systems. The acquired data are processed by the Fast Fourier Transform method and are compared to the harmonic and inter-harmonic data contained in a database, allowing the type of fault and the place to be identified within the low-voltage sub station, sending an alarm according to the level of the fault detected by the operator so that he may take the necessary actions for avoiding a catastrophic fault in the installation without risking the users.