Dsp-based Digital Signal Of Electrical Parameters Measurement Algorithm

DSP has the high-speed real-time signal processing capabilities, as a specialized digital signal processing chip, which is the starting point for improving the speed and design, and its instruction cycle is much shorter than generic PC and microprocessor. Not only the arithmetic speed is extremely quick, but also the hardware structure is helpful multiplication. It has great capacity for expansion and enormous addressable space, combined with digital signal processing algorithm for discrete Fourier (DFT) and the filtering algorithms; it is very easy to achieve electrical protection systems in the function parameters. In addition, the continuous analog signal by the A / D sampling into discrete signals, according to the system's function H (Z), become into a recursive formula by the Z-transform. It is especially for dedicated DSP digital signal processing instruction to be achieved.This thesis gets the relationship of DFT and Z transform based on the theory of DFT and Z transform and works out a Digital signal processing harmonic electric power real-time measurement of the new recursive algorithm. In electric system, the deferent signal is a labor frequency alternation voltage/ electric current signal. The electricity parameter exchanges the sampling data that the sampling full-wave Fourier algorithms need one to exchange the signal period generally. The algorithmic data window needs a frequency cycle and a longer response time. To shorten the time of calculating the full-wave Fourier algorithms and improve response time, it is necessary to use Fourier recursive algorithm. The recursive algorithm's notable feature starts with the first sampling point and calculates the fundamental harmonic of the real and imaginary parts of full-wave. Until the finally sampling point of full-wave is accomplished, the final result of the fundamental and the harmonics of real and imaginary part is carried out. From a macro perspective, the use of recursive algorithms for calculating Fourier amount distributed to each sampling cycle, the rise of real-time.This recursive algorithm formula reduces the amount of computation, thereby increase electric power real-time measurement. Namely, the sample point handling, while sampling side of the spectrum operations. When all the sample points are handled after the basic cycle of a time interval finally received and discrete Fourier transform as a result of the introduction of DFT algorithm and the Z-transform. Compare DFT to Z-transform, get the relationship of DFT and Z transform. Then, according to system function H (z) and the Z-transform, work out the output y (k) formula. Again using MATLAB simulation tests to carry out the calculation of 32 points and compare to the actual value. The simulation results are identical with the theoretical value. Finally, according to the formula derived recursive algorithms, run DSP Algorithm procedures on the DSP Experimental device. Analysis and discussion the improvements of new recursive real-time algorithm ,comparing with the Fourier algorithm.