The Research & Development Of Electricity Parameter Measurement & Harmonic Wave Analysis System Based On DSP

With the rapid development of science technology and national economy, diversekinds of industry production demand higher power quality; moreover, with the widely application of modern power electronics technology, power quality is deteriorated increasingly; therefore, more and more close attention is paid to power quality by bothelectric department and consumers. In this paper, the theory on power quality detection is researched in great depth. On the basis of the theory, the electric parameter measurement and harmonic analysis are designed and developed.This paper introduces the basic idea of applying DSP in the measure of electric power parameters. The sampling frequency can track the fundamental frequency automatically by using phase locking synchronous sampling technology. Detailed hardware circuit and software design are also provided. Measuring electric power parameters by digital signal processing technology has superiority in improving measurement precision and real-time. At the same time, digitizationg measurement makes the measurement system more intelligent and systematism. First electric power parameters, harmonic sources and modern measurement technology are analyzed, then the electric power parameters and harmonic measurement model based on FFT have been founded; In order to correct errors, the method of digital phase-locked synchronization is used to eliminate FFT leakage of frequency spectrum, wit validating it through simulation; at last, a real-time measurement system is designed and implement. With TMS320VC5416 as the centre processor, the system includes muti-channel data collecting, DSP data processing, FLASH data storage, and so on peripherial interface. A high quality three-phase signal generator and measuring function were combined in this system. Voltage and current synchronization collecting; Electric power parameters real-time measurement and harmonic real-time measurement;If used as the latter, electric parameters such as amplitude, virtual value and phase can be real-time measure. Key arithmetic in system's software design is detailed in this paper. Square root of one cycle serial express virtual value of current and volt; Square root of product of sequence of one cycle express the active power; The FFT is used to harmonics analysis. The other difficult arithmetic is also used, including arithmetic of computing the power factor, arithmetic of computing frequency and so on.The research is summarized in the end of this paper.