Análise e projeto de algoritmo de detecção robusta de afundamentos de tensão

Abstract

Power quality has been an important topic in the last years with usage of electronic loads in industrial activities. For this reason, several studies are motivated to search a solution for power quality problems. The dynamic voltage restorer is pointed as na efficient and low cost hardwaresolution. In this solution, it is required to detect voltage sag in order to inject a voltage in series transformer to compensate the sag. It has motivated several studies that propose algorithms to detect this disturbance from souce voltage measurenment. The required feature for voltage sag detection algorithm is speed for detection of the start and end times of disturbance. It is desarable that the algorithm yields instantaneous phase jump and deep of voltage sag. This work compares several traditional detection techniques from literature and proposes a committee based algorithm composed of selected techniques. This committee distributes weight to techniques according to the state of voltage sag presence in order to explore advantages of each one. Advantages and disadvantages of each traditional technique are shown in simulation with real measurenment data of sag in source voltage. The proposed algorithm also passes on simulations and it is proved it robustness to noise, harmonics and fast transitions. Finally, an experiment validated the proposed algorithm performance with real measurement from source voltage with programed sag. Both the traditional techniques and the proposed technique are proved by experiment and evaluated by results.