【正文】 .It is necessary to note that to receive a critical stability operating point in case when initial nodal capacities are set outside the boundary of the existence domain, there is no necessity to make any additional terms as the iterative process converges naturally to the nearest boundary point.Pulling the operation point onto feasibility boundary is not always possible by the shortest and optimal path. There are a number of constraints, such as impossibility of load (consumption) increase at buses, constraints of generation shedding/gaining at stations. Load following capability of generator units is various, consequently for faster pulling the operation point onto the feasibility boundary it is necessary tocarry out this pulling probably by longer, but faster path.The algorithm provides possibility of path correction of pulling. It is carried out by using of the weighting coefficients, which define degree of participation of eachnode in total control action. For this purpose diagonal matrix A of the weighting coefficients for each node is included into the objective function (2):All diagonal elements of the weighting coefficient matrix A should be greaterthan zero:When initial approximation lies into the feasibility domain, coefficients are not influence on the putational process and on the result.In the figure 4 different paths of the pulling the same operation point onto feasibility boundary depending on the weighting coefficients are presented. Paths are presented for two different operating points.In tables I and II。s method in optimization with a full Hessian matrix has been investigated. Calculations were made based on program MathCAD for a network prising three buses the parameters of which are presented in Figure variables were angles of vectors of bus voltage 1 and 2 ，independent variables were capacities in nodes 1 and 2, and absolute values of voltages of nodes 1, 2 and 3 were fixed.Fig. 1 – The Test schemeIn Figure 2, the boundary of existence domain for a solution of the steadystate is presented in angular coordinates δ1δ2. This boundary conforms to a positive value of the Jacobian determinant: As a result of the power flow calculation based on the Newton method in optimization, the angle values have been received, these values corresponding to the given capacities in (generation is positive and loading is negative).For the state points which are inside the existence domain, the objective function (2) has been reduced to zero. For the state points which are on the boundary of the existence domain, objective function (2) has not been reduced to zero and the calculated values of capacities differed from the given capacities.Fig. 2 – Domain of Existence for a Solution Boundary of existence domain In , the boundary of the existence domain is presented in coordinates of capacities P1P2. State points occurring on the boundary of the existence domain (6) have been set by the capacities which were outside the existence domain. As aresult of power flow calculation by minimization (2) based on the Newton39。s method in optimization [4]: (4) The Hessian matrix contains two items: (5) During the power flow calculation, the determinant of Hessian matrix is positive round zero and negative value of a determinant of Jacobian .This allows to find the state point during the power flow calculation, when initial point has been outside of the existence domain.The convergence domain of the solution of the Newton39。s method in optimization.As the algorithm based on the Newton’s method in optimization has considerable putational cost and power control cannot be realized in all nodes, the algorithm based on the bination of the NewtonRaphson methods and the Newton’s method in optimization is offered to be utilized for calculating speed, enhancing the power flow calculation.II. THEORETICAL BACKGROUNDA．Steadystate equationsThe system of steadystate equations, in general, can be expressed as follows: (1)where is the vector of parameters given for power flow calculation. In power flow calculation, real and reactive powers are set in each bus except for the slack bus. Ingeneration buses, the modulus of voltage can be fixed. W(X,Y) is the nonlinear vector function of steadystate equations. Variables Y define the quasiconstant parameters associated with an equivalent circuit of an electrical network. X is a required state vector, it defines steady state of EPS. The dimension of the state vector coincides with the number of nonlinear equations of the system (1). There are various known forms of notation of the steadystate equations. Normally, they are nodalvoltage equations in the form of power balance or in the form of current balance. Complex quantities in these equations can be presented in polar or rectangular coordinates, which leads to a sufficiently large variety forms of the steadystate equations notation. There are variable methods of a nonlinear system of steadystate equations solution. They are united by the incremental vector of independent variables ΔX being searched and the condition of convergence being assessed at each iteration.B. The Newton39。最后，衷心地感謝在百忙之中評閱論文和參加答辯的各位專家、教授！　參考文獻1 陳燕萍，王啟，趙彩虹等．2008．基于改進前推回代法的輻射配電網(wǎng)潮流計算方法[J]．南京師范大學學報，2008．8(1)：24~29．2 劉健,畢鵬翔,董海鵬． 復雜配電網(wǎng)簡化分析與優(yōu)化[M]． 北京：中國電力出版社， 2002．3 王守相，王成山．現(xiàn)代配電系統(tǒng)分析[M]．北京：高等教育出版社．2007．4 王丹，常寶立．一種用于配網(wǎng)潮流計算的節(jié)點編號新方法[J]．電力系統(tǒng)及其自動化學報．2003，15(1)：2226．5 何麗．地區(qū)配電網(wǎng)潮流計算方法的研究[D] ．哈爾濱：東北農(nóng)業(yè)大學 2009．6 [M]．北京：中國電力出版社1998．7 宋文南，李樹鴻，張堯．1990．電力系統(tǒng)潮流計算．天津：天津大學出版社．8 劉耀年，豈小梅，李國鵬，等．基于回路阻抗法的配電網(wǎng)潮流計算[J]．繼電器，2004，32(8)：810．9 汪宇霆，張焰，張益波．基于改進回路電流法的配電網(wǎng)潮流通用算法[J]．電力系統(tǒng)保護與控制，2010，38(20)：5761，68． 10 索南加樂，李懷強，羅云照，等．一種新的配網(wǎng)潮流常Jacobian牛頓算法[J]．西安交通大學學報，2002，36(12)：12221226．11 汪芳宗，