Research On The New Computer Protection Algorithm Of Power System

This dissertation is to study the algorithm of microprocessor-based monitoring and protection device, and its application on DSP platform. It begins with discussion of the ideas of algorithms, generalizes and concludes the principles of algorithms models, and advances a new cataloging method. Kinds of mainstream algorithms are introduced, and their stabilities and applications are discussed. Fourier algorithm is a widely used algorithm, and has been proved to be excellent in filtering harmonics. The dissertation analyzes its principle, and then extends it in digital signal processing domain, which focuses its uniformity with orthogonal function, discrete Fourier transform, sine and cosine digital filter. Because of the limitation of theory, Fourier algorithm is unable to filtering the periodic component, and especially poor in restraining decaying DC component which is common in current malfunction. The dissertation probes into all kinds of improvements of Fourier algorithms in common use, i.e., half-wave Fourier algorithm, full-wave Fourier algorithm and recursive Fourier algorithm. It analyses the precision and speed under the simulating condition of same malfunction wave and same sampling point in a cycle, and integrates factors as time delay and calculation amount, then gives the evaluation of performance.