| 摘要 |
The invention relates to a system for monitoring and diagnosing in power engineering field, meant for the symmetric and/or non-symmetric mono-phase or three-phase networks with highly deforming loads. According to the invention, the system consists of a physical system (1) wherefrom data are taken over and transmitted, by means of some measuring transducers (2) to a data acquisition system (3) which records and memorizes the data into an electronic memory (4) wherefrom the data are taken over by a calculation unit (BC), as files (5) with discrete signals, the calculation unit (BC) also taking over some parameters (6) specified by an operator, by means of an interface (7), the taken over signals being further transmitted to a calculation module (8) for determining the fundamental frequency and from here, through a module (9) for conditioning the signals by digital filtration, to a module (10) for analysis by the discrete Fourier transform which uses a virtual sampling frequency whose value is selected as a multiple integer of the fundamental frequency supplied by the calculation module (8), the thus decomposed signals being limited to a corresponding number of harmonic components, which are recomposed thereafter, the obtained result being compared with the recorded original signals, the error determination and the limitation thereof within a certain value range, validates the results in the calculation unit (BC), that allows the determination, at the level of a calculation module (13) of the significant harmonic components of the voltages and currents, quality indicators of electric energy and the spectral components of powers, all these constituting output data (14) as text files and graphical representations. |
