Divergence Mechanism On The Newton Power Flow In Rectangular Form With Small Impedance

The Power flow is the core and foundation of the power system’s analysis,It belongs to the steady-state analysis, and widely used in power system’s operation, scheduling, planning, analysis of security and reliability, and plan for optimal adjustment. However, with the increasing complexity of the power system development in modern society, there are more and more ill-conditions in the power system, which often cause the power flow unsolved, or make the power flow divergent with the conventional methods. To this end, the positive study on the convergence of power flow is particularly important and very meaningful.Flow in mathematics is actually solving the problem on a set of multivariate nonlinear equations to, its solution can not be separated from the iterative process, convergence is an important indicator to measure the trend of performance of the algorithm. Of this algorithms Researchers proposed, the Newton power flow for solving nonlinear equations is very effective and widely used in power flow.Power systems with small impedance branches are a common ill-condition, which may lead to the divergence of the power flow. When analysising the convergence of Newton power flow with small impedance branch, standing at the point of mechanization of convergence is useful. Newton flow for linearization of power flow equations is based on the Taylor expansion. With the small impedance branch, in the process of non-linear flow equation to linear, Partial derivatives of Taylor expansions are great, resulting in more than able to ignore conditions, if still calculated in accordance with the traditional Newton, then the flow calculation convergence naturally can not be guaranteed, and thus become the trend of the Newton method to calculate the divergence of the main reasons. The theme of this paper is to improve the Newton power flow of the Newton method to solve the problem of ill condition which trend of divergence.Based on the deeply analysis on Newton process and combined with the characteristics of the small impedance branch, an improved Newton power flow in rectangular form for systems is presented. Its purpose is by changing the remainder part to smaller, end to satisfy the ignorance, the remaining part and the original equation can be obtained, then get the solution and verify the convergence. Its essence is to proceed from the structural defects of Jacobian, fix the elements of the Jacobian to get the purpose of improving convergence performance. Small impedance branch system theoretical analysis and numerical results show that the improved flow can make a small impedance branch’s flow convergence.