Research On Optimal Placement For FACTS Devices Based On Reliability Cost/Benefits Analysis

This dissertation is supported by National Natural Science Foundation of China (50977094) and Scientific Research Foundation of Stage Key Lab. of Power Transmission Equipment and System Security(2007DA10512709103).The Flexible AC Transmission(FACTS) technology is produced to solve the operation of the transmission grid and difficulties encounterd in the development . FACTS technology as new solution which has its unique advantages in the respect of controlling the grid flow, improving the system statbility ,reliability, the capacity of the transmission line and so on. So it has been widely recognized. In this paper, both economy and reliability are considered, the optimal placement model of FACTS devices based on reliability cost/benefit analysis is presented. The main content is the following:â‘ By the research of the reliability cost/benefit analysis, the total cost of the grid which incorporates the FACTS devices can be obtained, the cost is based on the reliability cost/benefit.In this paper, the total cost is the optimization goal to optimize the configuration of FACTS devices. Based on the different types of the FACTS devices, all kinds of FACTS devices is introduced. The paralled type of FACTS devices static synchronous compensator(STATCOM) and the series type of FACTS devices thyristor controlled series capacitor(TCSC) are selected to study. The principles, flow models and reliability models of two FACTS devices are detailed analyzed .â‘¡The reliability model which incorporates the FACTS devices is researched. State enumeration method is used to select the various system state. Each of the system state is analyzed and the optimal load shedding model incorporating the FACTS devices is obtained.Finally, The reliability index is accumulated to obtain the risk assessment index of the grid incorporating FACTS devices. In order to account uncertainties, talking into account in the load curve for the reliability assessment is made.The reliability evaluation index which before and after installing the FACTS devices is compared and analyzed. In the reliability evalution,the sensitivity fomula of the system Expected Energy No Supplied(EENS) to the controlling parameters of FACTS devices can be obtained by the constraints in the fimicon function. According to the size of the sensitivity index the FACTS devices can be placed,at the same time, the expected capacity index is calculated to determine its capacity.â‘¢The successive iterative algorithm for the proposed optimal placement model utilizing the heuristic idea is achieved.: sensitivity analysis is used to indetify the installation location of FACTS devices, then the expected capacity index is calculated to determine its capacity. Finally, the optimal placement model which can achieve the minimum cost for FACTS devices placement scheme is verified using the RBTS reliability test system.