Research About Power Quality Monitor Based On ARM And DSP Chip

Electrical energy is the broadest used energy and its application level has become a main development level symbol of a country. With the development and popularization of computer, power electronic and information technology, more and more attentions of power system departments and consumers turn to the power quality. So it's very significant to measure and analyze the power quality. This paper has the research on the theory and technology of power quality, and designed the hardware and software of double CPU power quality monitor based on DSP and ARM chip.Firstly, this paper analyzed the current research situation of power quality home and abroad, expounded the analysis methods related to power quality, and put forward the design thoughts on power quality monitor. This paper adopted double CPU hardware structure, using ARM to manage the man-machine interfaces, such as keyboard and display, using DSP chip TMS320LF2407A to take charge of digital signal processing, using 14 bits AD conversion chip to realize high accuracy A/D conversion, and using Phase-Locked Loop (PLL) circuit to track the power net frequency. The software system used module design method for future upgrade. There were also several theoretical researches. Six-pulse Bridge, which is one of the main harmonic sources, was chosen as the research object. The theoretical analysis showed the link between control angle and harmonic current. And it also showed the link between commutation overlap angle and harmonic current. A simuliation module was founded with PSCAD/EMTDC software. The simulation results were similar to the theoretical analysis. Wavelet transform was used to analyze the disturbance signal.Finally, the field measured data was analyzed, and the problems which existed in current power qulity were pointed out and the corresponding solutions were presented. The error analysis of power qulity monitor was done in the paper.