Research On Application Of An Intelligent And Fast Switch Series Capacitor To 25kV Radial Power Distribution Network

The target of any electric power system is providing consumers with sufficient electrical power.They do not want reliability only but also demand high power quality.The delivery of electric power by long radial distribution line in the rural area faces up many problems.The first problem is that voltage quality cannot meet the requirements of a load because the line resistance and inductance are the two main significant factors causing an increase in voltage drop and power losses.Also,the synchronous motor or a squirrel cage induction motor consumed a high reactive power during starting operation,and the effect is even more extensive than that of consumed power during regular operation.The voltage drops during starting motor may be very high that it is not appropriate to the other clients connected to the network.In the worst case,the high reactive power consumed during motor starting causes the exaggerated voltage drops,thereby unable the motor to run.The investigators introduced some compensation techniques to solve this dilemma.However,the research of a unique solution to overcome this problem during different load conditions and power factor is a hot research topic.Therefore,this thesis discovered that the series capacitor compensation has ideal characteristics to improve voltage quality,and these characteristics are not available in other compensation techniques.Also,the thesis introduces the comparison,evaluation and analyzes of the effects and characteristics of series and shunt capacitor compensation application in the radial power distribution grid during different load conditions and power factors.Furthermore,a fixed series capacitor bank supplies the motor with adequate voltage during starting.The second problem is that the sub synchronous resonance problem in asynchronous/synchronous motor during starting operation should be considered during inserted fixed series capacitor bank in the network.This sub-synchronous resonance is riskier if the degree of compensation is too high.However,to solve the problem,this thesis also suggests a new solution instead of conventional method to avoid the sub-synchronous resonance problem.The Third problem is that series capacitor exposes to the overvoltage severity and causes increasing in fault current level when the fault occurs in the network.Therefore,this thesis introduces an intelligent and fast switch series compensation device as a new technology for protection performance of series capacitor instead of the conventional protection method to overcome the overvoltage severity and mitigate the fault current level as well.This new technique has an advantage in terms of the compact size of power equipment,high performance and less environmental hazard.Also,the thesis presents a comparison between the results of the new protective device and conventional protective equipment during various types of fault such as Ph-g,2Ph-g,and 3Ph-g fault.Throughout the investigation mentioned above,simulation has been carried out with the help of MATLAB/SIMULINK during different load conditions and power factor in healthy and faulty conditions.Since a long time ago,there has been an utmost need for more airtight.cogent,coherent and environmentally robust equipment.Therefore,the fast switch series compensation reduces the number of MOV,which in turn,more economical,efficient and compact size of FSCB.