Research On Orientation For The Disturbance Source Of Power Quality

Nowadays the sources affecting the power quality are getting more and more,such as nonlinear load widely applied and kinds of the faults in the power grid which may endanger the normal operation of the power system due to the power system is growing much huger and intelligent than ever. On the other side the customers' sensitivity to the power quality is increasing as the output quality and cost are influenced by the power quality status directly. Therefore the problem of power quality becomes a hot spot concerned by the utility side and the customer side both.At present the monitoring systems applied could not provide enough information on the disturbance, especially on locating the source of the disturbance which leads to the occurrence of the faults weightily. Thereby to identify the disturbance in the power grid and to locate the source of disturbance show significant meaning to the safety and stability of the operation of the power system. Along with the scale of the power system enlarging, the disturbance sources are becoming more and more, the hazard also rises. Consequently the disturbance source needs to be identified and located for early warning before it causes fault.The main work of the thesis is on the theory and arithmetic to resolve the practical problem of undetermined disturbance sources in some zones, then to distinguish the responsibility of power quality pollution and to try to identify and locate the disturbance source as early as possible in order to reduce the loss.The achievements in this thesis are as followings:(1) According to the analysis of the fundamental characters of the disturbance source and mechanism of the disturbance birth, the orientation theory for flicker based on the nonlinear load and algorithm was proposed.(2) By taking advantage of the theory on energy signal, a new method to determine the voltage sags and swells was advanced on the base of the Parseval theorem that could be utilized to detect the capacitor switching and overvoltage caused by the breaker operations.(3) By using the visual instrument technique, a designed plan was put forward which shows the advantages including agile design, easily upgrade, fine expansion flexibility. It is with simple maintenance and easy to use.