An Approximate Linear Power Flow Calculation Method Based on Logarithmic Transformation of Voltage Amplitude

Abstract

The invention discloses an approximately linear load flow calculation method based on voltage amplitude logarithm transformation. The approximately linear load flow calculation method comprises the following steps: firstly, carrying out linearity on a general branch current formula containing a transformer and a phase shifter; secondly, carrying out linearity on an active and reactive load flow equation set; thirdly, establishing the linear expression of a branch complex power load flow containing transmission load; and fourthly, according to actual conditions, determining whether injection power compensation is used, and solving the linear load flow equation set so as to obtain the operational variables such as voltage amplitude and phase angles, branch active and reactive load flows. According to a voltage amplitude logarithm transformation method used in the invention, the voltage amplitude is replaced by a natural logarithm during modeling calculation, and the inherent nonlinearityof the load flow equation set is maintained to a certain extent. The model is solved by using the linear equation set, and iteration is not needed, so that the calculation speed is high. The method can be used for the fields such as electric power system reliability assessment, electric power system economic dispatch and online static safety analysis.

Description

technical field [0001] The invention relates to the technical field of power system operation analysis and power flow calculation, in particular to an approximate linear power flow calculation method based on voltage amplitude logarithmic transformation. Background technique [0002] Power flow calculation is the basis of power system planning, analysis, operation and evaluation. Compared with the traditional accurate AC power flow calculation, the linear power flow calculation (LPF) has faster calculation efficiency, and is widely used in power system planning, reliability assessment and other occasions where it is difficult to obtain data or the accuracy is not high. In the context of the electricity market, linear power flow calculations are also widely used in areas such as economic dispatch, unit combination, or cost allocation in the electricity market. [0003] However, the classical direct current power flow (DCPF) method and some existing linearized power flow meth...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the problem of inaccurate and incomplete estimation of various operating variables in the existing linearized power flow method, and proposes an approximate linear power flow calculation method based on voltage amplitude logarithmic transformation, using voltage amplitude logarithmic transformation method, the voltage amplitude is replaced by its natural logarithm in the modeling, which retains the inherent nonlinearity of the power flow equations to a certain extent, and has high accuracy and speed

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