Research On Sectionalization Methodology For Power System Considering Restoration Procedure

Due to the limitation of technical and economic conditions,blackout accident cannot be avoided completely and may have a huge impact on society.When a blackout occurs,the whole system where there is more than one black-start power source can be divided into several subsystems.By restoring these isolated sections in parallel,the restoration is accelerated and the cost is reduced.Most existing research of sectionalizing strategies mainly focuses on the inherent properties while the influences of divisions on practical restoration procedure are usually overlooked.As a result,the restoration speed varies in different islands and the islands with short outage duration have to wait the rest before synchronization.In addition,it’s hard to consider various factors such as the characteristics of generators and loads.The disagreement between the theoretical model and practical requirement cannot be avoided.In a word,the balance of topology cannot ensure the excellent performance in restoration and the efficiency of black start still remains to improve.Therefore,the research on sectionalizing methodology considering restoration procedure for power system has an important significance.In order to recover the power system rapidly and effectively,this paper researched the optimization of sectionalizing methodology for parallel power system restoration considering restoration procedure.The main work was completed as follows:Firstly,different sectionalizing methodologies based on grid topology were analyzed.By studying existing clustering and splitting algorithm,the impact of overlooking the restoration procedure was discussed.As a result,the necessity of the research in this paper was expounded.Secondly,the optimization model of sectionalizing methodology considering restoration procedure was established and the objective was minimizing the sum of load loss.After the restoration process was analyzed,the constraints such as power flow constraint were taken into account to ensure the security and stability of power system during the restoration.Thirdly,the proposed optimization model was divided into two optimization problems and solved by the bi-level programming.On the upper level,the feasible solutions were generated by cut set based on sectionalizing principles.The ordinal optimization was introduced to ensure good enough sectionalizing schemes with as high as enough probability.On the lower level,the units and load restoration sequences were scheduled to minimize load loss within each island.Finally,the feasibility and effectiveness of the proposed methodology was validated by the simulation of IEEE-39 test system and a certain power system in Jiangsu.