An Optimal Control Strategy of Reactive Power and Voltage for UHVAC Power Transmission System

It is inevitable for the development of power grid in China to adopt UHV power trasnmission,and the control of votlage and reactive power are the research topics that the researchers of UHV power transmission pay special attention to.In this paper,the definition of traversing reactive power is given and the energizing power of long tansmission line,the loss of reactive power,the highest votlage alone the line and the position where it appears are analyzed;based on the reason by which the traversing reactive power occurs,the relation between modulus value ratio of sending terminal voltage to receiving terminal voltage and traversing reactive power composed of three parts,i.e.,the demand of compensation for reactive power,the amount of reactive power compensation,loss of reactive power of power transformers and the switching on/off number of shunt low voltage capacittor banks or shunt low voltage reactors are analyzed in detail,herefrom a mathematical model for optimal control of reactive power and voltage of UHV power transmission,in which the minimum traversing reactive power is taken as objective,is built,and the numerical algorithm for the optimal solution of this model is given.Smulation results show that both the proposed optimal control strategy and algorithm are effective.