System Of Real-time Power Quality Monitoring And Management For Distribution Network And Reaserch Of Impvoving Measurement

With the development of power system, and the increased nonlinear and impact load were used, the problem of power quality is more and more rigorous, however the social requirements to the power quality are growing, to improve the power quality, the most important thing is to detect and supervise the power quality parameters in a whole day and omnibearing. Therefore, a kind of hierarchical distributed system of real-time power quality monitoring and management for distribution network was proposed and developed. The system has operated well in a 110kV Substation in the Guangxi Zhuang Autonomous Region, and provided lots of power system information and reference for the power quality improvement.Firstly, the paper briefly introduces the definition, sorts, indexes and national standards of power quality, emphatically analyzes the advantages and disadvantages and application scopes of common harmonic detection methods at present, and improves the fast fourier transform as the harmonic detection method of system.Secondly, a hierarchical distributed system with three layers is designed according to the substation's whole structure and distribution of electrical equipments, where, field interval layer is responsible for collecting grid real-time data and communicating with front end computer. Network communication layer connects field interval layer with management application layer and packing process the data from bottom layer, then transfer to above layer. Management application layer is user interface part, realizes the gathering and display of information with multi-formats, and has power quality's real-time treatment simulation and system management and etc.functions. Subsequently, the hardware composing and software design of system is described, including intelligent detection terminal in field interval layer, data sampling and sending module in network communication layer and power quality management system in management application layer.Then, three kinds of common-used power quality improving measures are analyzed according to the power quality situation of a 110kV Substation in the Guangxi Zhuang Autonomous Region. In order to overcome the inconsistency of harmonious injecting capability and active power overplus, the paper brings forward a new kind of hybrid active power filter with double-resonance injection circuit, whose topology strutrue, harmonic suppression principle and harmonic magnificati instance, and the method of harmonic detection and control are analyzed. In addition, the advance and validity are validated by PSIM emulation.In the end, field installation and adjustment is done. Meanwhile, the actualizing scheme of power quality treatment is preliminary designed to provide theoretical guidance and technical reference for next engineering realization。...