Open AccessAnalysis of Real Overvoltage Disturbances by Using Nonstationary Signal Processing Techniques
Author(s) -
Snežana Vujošević,
Saša Mujović,
Miloš Daković
Publication year - 2015
Publication title -
advances in electrical and computer engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.254
H-Index - 23
eISSN - 1844-7600
pISSN - 1582-7445
DOI - 10.4316/aece.2015.03004
Subject(s) - overvoltage , signal processing , computer science , signal (programming language) , digital signal processing , electronic engineering , real time computing , electrical engineering , engineering , computer hardware , voltage , programming language
Switching surges can cause voltage conditions degradation, and this paper presents a new approach in their analysis. Besides the amplitude properties, regarding to power quality, it is important to know the structure of their harmonic spectrum. For that purpose, characteristic surges (energization and deenergization of an unloaded 35 kV underground cable, energization of an unloaded 10 kV underground cable and deenergization of a 10 kV overhead line, with a multiple appearance of the arc between the circuit breaker contacts) were analyzed. The signals were obtained by an experiment, so the occurrence of noise makes them much more complex to analyze than the simulated ones. Their harmonic decomposition was performed by digital signal processing methods - Empirical Mode Decomposition and Short Time Fourier Transform. The obtained results were compared to the calculated ones, which allowed us to draw conclusions related to applied methods efficiency and characteristic harmonics values that occur during the switching surges. The performed analysis allows us to get a deeper insight into transient processes in the real transmission power lines. The obtained results can be especially useful to detect the locations of occurrence of various types of surges and for development of real-time power quality monitoring systems