Voltage initial value setting method of load flow calculation with rectangular coordinate newton method

Abstract

The invention discloses a voltage initial value setting method of load flow calculation with a rectangular coordinate newton method, comprising the following steps: threshold value of a low impedancebranch circuit is determined, and the branch circuit less then the threshold value is defined as the low impedance branch circuit; initial value of a voltage image part is taken as 0.0, a set value ofa voltage real part of a PV node and a balance node is taken: the initial values of the real part of node voltage at two sides of the low impedance branch circuit are chosen, so as to meet the formula: ei=kej; the undetermined voltage initial value of the real part of the other nodes are taken as 1.0. By improving the voltage initial value setting method, the convergence problem of load flow calculation with the rectangular coordinate newton method can be effectively solved. The method has the characteristics of clear concept, simple programming and good convergence. The calculation only aimsat the low impedance branch circuit to specially choose, for a normal branch circuit, the initial value is chosen according to a level starting way still, thereby having not effect on the convergenceof the load flow calculation without a low impedance branch circuit system.

Description

technical field [0001] The invention relates to a power flow calculation method of an electric power system, in particular to a voltage initial value setting method for the rectangular coordinate Newton method power flow calculation. Background technique [0002] In the Cartesian coordinate Newton method power flow calculation of the power system, the node voltage is expressed in Cartesian coordinates as: [0003] [0004] Each node in the power system has four operating variables: active power P, reactive power Q, voltage amplitude V and voltage phase angle θ. In general power system power flow calculation, two operating parameters are often given as known conditions for each node, while the other two are used as required quantities. According to the way given by the original data, the nodes in the power system are divided into the following three types: [0005] 1. PQ node [0006] For such nodes, P and Q are given, and V and θ are to be requested. [0007] 2. PV no...

AI Technical Summary

Problems solved by technology

[0103] It can be seen that the Cartesian Newton method power flow calculation may not converge when analyzing ill-conditioned power systems with small impedance branches

Images