A Study On Practical Technology About Static Security Check Of Large Grid’s Dispatching Plan

With the rapid development of these years, China’s power grid has entered a new era of large grid and UHV. The large power grid can improve stability and economic efficiency of the system. However, the large power grid calls for higher demand to dispatching plan, or it cannot manage the large power system well. This paper mainly talks about practical technique about static security check(SSC) of large grid’s dispatching plan in order to improve the accuracy and accelerate the computing speed of SSC.SSC includes power flow computing, static security analysis, sensitivity analysis and short-circuit current calculation. Firstly, the research status at home and abroad of practical technique about SSC is talked about. Secondly, we study the basic theory of SSC from the practical viewpoint. And lastly, the features of SSC are summarized.Currently, we usually use a fixed network loss based on experience when computing PF. However, the fixed network loss we estimate is rough, and it cannot guarantee output of generators follow the generation plan, especially the slack generator. This paper proposes a estimating method of network loss based on forecasting and correcting that can guarantee output of generators especially the slack generator follow the plan output. We test this network loss estimating method in the IEEE14bus network and IEEE30bus network with the toolbox MATPOWER in MATLAB and also test it in the D5000system. The test results show that this method is correct. It can guarantee outputs of generators follow the plan, also it makes sense for improving the accuracy of PF.There are96plans for the day-ahead dispatching plan. We should check every plan, so there are96plans that should be checked. However there is no relationship between any two from the96plans, they are parallel. We can use parallel processing technique to solve several plans’checking at the same time in order to accelerate the computing speed of SSC. With the development of computer technology, multi-core parallel computers are common. This paper study how to use multi-core parallel computers to solve the tasks of checking the96plans, and test it in the D5000system. The results show that the parallel processing technique can greatly improve the computing speed of checking the day-ahead dispatching plan.