Research On Classification Method Of Power Quality Indices

Power quality indexes can be used to quantify the level of power quality disturbances quickly. And it is also the data base to describe the negative effects of disturbances on electrical equipment, attain standardized evaluation and propose the effective recommendations to improve and control power quality. With the rapid economic development and technological progress of our country, the study and application of power quality indexes receive more and more attention and concern. And the study of power quality classification is the most important task of power quality indexes research.Modern power quality indexes have the feature of diversity, and different indexes have the different causes and effects of electrical equipment. Different indexes have another impacts of different users, thus the users have the different focus on the power quality. The user sensitive to voltage sag may be concerned with the voltage sag index merely. Harmonic-sensitive user may also be the same token. Some users have a high demand on the overall quality of supply, they may be concerned about the overall level of power quality. From the perspective of the electricity sector, there’re some standards to assess the satisfactory of power quality. However, there is not a reference or standard to judge the merits of power quality.Harmonic levels were classified in this paper based on the causes and effects of power quality. Voltage sag levels were classified based on the area of voltage sag and sensitive area of typical devices. Analysis and comparison of comprehensive power quality indexes and comprehensive assessment of power quality, this paper presents the classification methods of comprehensive power quality indexes.