Voltage Sags By Transmission Line Of Dongguan Power Grid Fault Analysis

With the development of national economy and society,microelectronics technology has made great progress,electronic computers,automatic control devices and a large number of high-power power electronic devices widely applied to all areas of the national economy.These microelectronic devices and devices are very sensitive to changes in voltage,even if a little bit of voltage fluctuations will have a significant impact on their accuracy,longevity and normal operation.Therefore,relative to the traditional power users,these sensitive loads on the power system power quality put forward higher requirements.Perhaps only a few cycles of voltage sag will have a significant impact on these devices,resulting in irreparable economic losses.Therefore,it is very important to study the types of voltage sags,the influence characteristics,the detection and analysis methods,and the monitoring and prediction of voltage sags.In this paper,the causes of common voltage sags and their effects on voltage sensitive devices are introduced.The voltage drop characteristics are analyzed,and the common detection algorithms of voltage sag are simulated and the advantages and disadvantages of each algorithm are compared and analyzed.Then,the calculation of the load tripping amount in the case of voltage sags in the grid is carried out,and the calculation model of the load tripping amount is established.The corresponding load tripping amount is calculated when the voltage of each node is sagged,The example shows that the method is small in workload,has good operability and has good practicability.Finally,in order to better realize the voltage sag condition monitoring and risk assessment,this paper establishes a Monte Carlo voltage drop probability evaluation model,taking full account of the effects of various stochastic factors such as fault type,fault line,fault location,fault duration,The risk prediction of the influence of the voltage sag on each node under the main network failure is realized.Through the establishment of the monitoring point optimization configuration model,the whole network voltage sag monitoring point reasonable allocation,can be in a minimum number of monitoring devices to achieve the whole network voltage sag visibility,both to save the cost,but also to avoid a large number of redundant The data of this paper can provide a good theoretical basis for engineering practice.