Development Of A New Surveillance System On Power Quality

A power quality surveillance system is developed in this thesis. At present, our country power quality national standard was chiefly stipulated six quotas: frequency, harmonic and voltage deviation, three-phase imbalance, the voltage fluctuation and flicker, temporary power quality.Based on the analysis of the similar productions of other countries and manufacturers, we put forward our design. The front-end section of the system samples the voltage of each bus and the current of each line using DSP (Digital Signal Processor).Then the indexes of power quality can be calculated and the result can be sent to advanced management computer by field bus. Object-oriented programming language——Microsoft Visual C++ is used to develop the background software, which can deal with the data send by DSP and the result can be displayed. This system is adopted to measure most of power quality parameters including voltage, current, power, frequency, harmonic, three-phase imbalance degree and the voltage fluctuation. What's more, the theories are studied and those functions are realized.The front-end surveillance equipment on power quality is centered at DSP chip (dsPIC30F6014), which has strong ability of control, high speed calculation and special instructions for data processing. This chip is convenient for developing because it has integrated rich peripheral units. The equipment can perform the following duties: A/D transformation, data sampling, data processing, man-machine conversation, displaying and communication. The hardware and software design are introduced on this paper in detail aimed at the realization of these duties. In the aspect of algorithm, this paper designs the algorithm of electric parameter and harmonious analysis which are suitable to fixed-point DSP, and compiles program to practice the algorithm on the practical device. To the background software, the design of the communication module is chiefly introduced.The system is completed successfully and the measuring result is correct and accurate. It proves the theory analysis is correct and the design of hardware and software is reasonable.