Online Power Quality Monitor Based On Parallel Processing

With rapid development of the national economy, power quality has become the most concerned issue of the world. For one thing, the increasing factor which affects the power quality, for example, the distorted wave of voltages and currents caused by the extensive application of power electronic apparatus and nonlinear equipment and the frequently turning on and off of the large electricity-consumption facilities, has worsened the power quality. For another, the exactitude and precision production process of some hi-tech corporation, such as chip manufacturing, auto-control facilities in the consecutive and experimental facilities. As the result, the modern industry demands more high quality power supply.The traditional monitoring technology based on the virtual value theory cannot precisely describe the power quality problem due to the much-long time window, so a new monitoring technology is wanted to meet the high-level needs. The power quality monitor is the primary technique to discovering and analyzing varies power quality problems, and it provides important warrant to the diagnoses of the hitch in power system. The existing power quality monitor equipments mostly using the serial processing of sampling and analyzing when they analyze multi-index of power quality online. This has led to the sampling' s breaking off during the digit processing, and lost vast real-time data. At the same time, the analyzing of power quality, such as the harmonic analyzing and the flicker analyzing, needs some complicated arithmetic(FFT, WT and soon). So the monitor equipment demand fast digital signal processing speed and high technique of parallel processing. This paper advances the structure of parallel processing based on FPGA and DSP to achieve non-gapped sampling and analyzing of power quality.Based on the demand of the power quality' s harmonic monitor and the specialty of large scale programmable logic device, this paper advances a frame of a 24-bit float point FFT module in FPGA. This module, with the DSP based monitoring of the flicker described in the backmost of the paper, buildup the parallel processing hardware-structure. At the same time, FPGA produce the sampling control signal and the analyzing controlling signal simultaneously. This structure, utilizing advantages of both FPGA and DSP in the field the digital signal processing, has the merits of agility, easy upgrade and universal ability.