Study And Design Of Newton-Raphson Load Flow Based On Rectangular Coordinates For Scientific Research Purpose

Electrical energy is playing an increasingly important role in the development of modern society and daily life.The demand for power supply reliability and power quality is also higher and higher.Power flow calculation is a basic operation in power system analysis.According to the different purposes,load flow can be divided into research-oriented power flow and engineering-oriented power flow.The research-oriented load flow algorithm is mainly used as a computational tool in the research,the prominent feature of this algorithm is that the matrix element is easy to modify and has good maintainability,which makes this algorithm often be used for further development.With its powerful function,Matlab is gradually used by more and more researchers.Therefore,in the research work,there is also an urgent need for a power flow program implemented by Matlab to carry out relevant analysis.Firstly,the research-oriented power flow algorithm based on loop structure is studied,and a method of loop structure of Jacobian matrix is designed.Based on the arrangement characteristics of Jacobian matrix elements,an algorithm for solving linear equations is designed.By designing a method of extracting non-zero line,the matrix inversion is solved.Then,the algorithm of research-oriented power flow based on matrix operation is studied,which includes three parts:the formation of initial Jacobian matrix,the revision of Jacobian matrix and the calculation of amount of unbalance.Among them,the formation of the initial Jacobian matrix and the revision of Jacobian matrix are based on complex power.A method of forming Jacobian matrix by matrix operation is deduced,which greatly improves the computational speed compared with the loop structure.By using matrix operation,an efficient method for the calculation of amount of unbalance variables is designed,which is more efficient than the traditional loop structure.Finally,the algorithm is analyzed by using the data of 445-bus power system of Northeast China Power Grid.The results show that the algorithm designed in this paper meets the requirements of scientific power flow algorithm in speed,and has obvious speed advantages and strong practical value.