Optimal Allocation Of Dynamic VAR Sources Considering Voltage Safety Constraint

Voltage stability is one of the important research contents of the power system.With the increasing proportion of induction motor load and the increasing application of high-voltage direct current transmission,new energy generation and power electronics technology,the transient voltage stability problem of power s ystems has become increasingl y prominent.Dynamic VAR sources such as SVC can quickly provide d ynamic reactive power support and improve s ystem d ynamic voltage performance after faults.Therefore,it becomes one of the hot issues in power s ystem operation anal ysis.The common d ynamic VAR sources optimization algorithm is to evaluate the reactive power of the compensation point through sensitivity anal ysis,select the compensation location by the sorting method,and finally optimize the capacity.But this method is likel y to cause redundant capacity.This paper proposes a s ystematic optimal allocation of d ynamic VAR sources.The specific implementation method is as follows.Firstly,the electrical distance is defined by means of the node impedance matrix,which is used to reflect the dynamic voltage similarit y between nodes.Spectral clustering algorithm and silhouette coefficient are applied to divide the power s ystem into several voltage control zones so that nodes with high electrical similarity are in the same zone,while nodes with low electrical similarity are in different zones.Based on the voltage control zone,this paper proposes a d ynamic voltage performance index based on TV I(Trajector y Violation Integral)and a screening method for critical contingenc y set.Further,a voltage support index VSI is proposed,which is applied to select candidate installation sites with higher sensitivity in each zone.Finall y,this paper proposes a distributed capacit y optimization strategy.This method can quickl y estimate the d ynamic reactive power compensation capacit y of each area and determine the best installation sites.Then,with the estimated capacit y as the initial value,t he particle swarm optimization algorithm is used to optimize the d ynamic reactive power compensation capacit y of the whole s ystem.In the end,the effectiveness and advancement of the proposed method are verified b y the New England 39-bus system.It shows that t he advantages of the proposed method include: optimizing the reduction of search space,reducing complexity of models and reducing the amount of calculation.Therefore,the method proposed in this paper can provide technical and decision support for the operation of the power s ystem and has good application potential in large-scale power systems.