Research And Implementation Of Power Quality Monitoring And Evaluation System Based On Internet

In recent years, power quality (PQ) has gradually become an important concern. With the industrial-scale expansion and development of science and technology, electrification has become more and more widespread and new technologies are widely used in industrial production and various aspects of people's lives. All sorts of complex and precise apparatuses, which are sensitive to PQ, are increasingly becoming popular and customers are also demanding much higher PQ for their apparatuses. At the same time, more and more nonlinear loads, such as rectifier loads and impulse loads, have been used in the modern power system (PS). These nonlinear loads will result in bad power quality, such as voltage distortion, voltage fluctuation, flicker and three-phase unbalance. The impact on the safe operation of PS and the correctly working of equipments is continuously increasing, which has caused general concern of power management and customers.In the power market, power has become a peculiar commodity provided by power management to customers as power supply and service. How to monitor and assess PQ has become a important prerequisite for PQ management. The Online and Real-time Monitoring and Assessing System of PQ is the important tool of the modern PS in the PQ monitoring and management.This paper used the attribute recognition theory to construct the measurement evaluation matrix(MEM) based on the measurement attribute of external dates of targets of PQ. The paper present G1-Entropy Method to determine the weights of PQ indices by making use of the attribute between the objective weight of and MEM. This new method overcomes the one-sidedness of single-weighing and reduces the amount of computation and leads to a more objective and accurate result.This paper gives a design of the Power Quality Monitoring and Evaluation system and implements all modules of the system in order that power departments can master PQ timely and accurately. The system which is based on computer technology and net communication technology is modular in design, and it has a strong scalability and compatibility. The modular of the geographic information is designed by the MapXtreme ActiveX so that it has enriched the map's information. The system has more progressive than the traditional power quality monitoring system and enhances the normalizatione and interoperability of the power quality management. By integrating these monitoring stations in the power grid, achieves on-line monitoring system of power quality and guarantees real-time and reliable transmission of data.