A Linear Method for Calculating Power Flow of Three-phase Distribution Network Based on Loop Analysis Method

Abstract

The invention discloses a loop-analysis method based linear method for calculating a three-phase power distribution network tide. The loop-analysis method based linear method comprises the following steps: obtaining the relation function of node voltages and node injection currents of a power distribution network according to a loop-analysis method; for a single-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load, a constant power load and a mixed mode respectively, and introducing in the relation function for calculation to obtain node voltage values; and for a three-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load and a constant power load, and introducing in the relation function for calculation to obtain node voltage values, wherein the three-phase system comprises a star connection load and a delta connection load. The method disclosed by the invention is high in calculation efficiency, few in occupied resources and high in calculation accuracy.

Description

technical field [0001] The invention relates to the field of power grid distribution, in particular to a linear method for calculating the power flow of a three-phase distribution network based on a loop analysis method. Background technique [0002] With the rapid development of the national economy and the improvement of people's living standards, people's demand for electricity is increasing, and at the same time, higher requirements are put forward for the reliability and quality of power supply. Reasonable distribution network optimization is an important basis for power system security, stability and economic operation. [0003] Most power system optimization problems are essentially optimal power flow problems for different objectives. These algorithms are nonlinear algorithms. Power flow calculations need to be solved iteratively, and in some abnormal situations such as heavy burdens, the convergence may be slow or even slow. Convergence, the conventional nonlinear ...

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Problems solved by technology

[0003] Most power system optimization problems are essentially optimal power flow problems for different objectives. These algorithms are nonlinear algorithms. Power flow calculations need to be solved iteratively, and in some abnormal situations such as heavy burdens, the convergence may be slow or even slow. Convergence, the conventional nonlinear power flow calculation can provide an accurate result, but the calculation time is long and the storage space is large

[0004] The direct current power flow algorithm (DCPF) is a linearized approximation method of the traditional Newton-Raphson algorithm, which can directly calculate the power flow without iterative calculations and is absolutely convergent. However, because the DCPF calculation ignores the line loss, reactive power and voltage changes, that is, it is assumed that the voltage remains constant, but this condition is difficult to guarantee, so the accuracy of the algorithm is low, and in some abnormal situations , the error is large, and even cannot meet the engineering requirements

[0005] To sum up, the existing nonlinear power flow algorithm takes a long time to calculate, has low calculation efficiency, and consumes a lot of resources, while the DC power flow algorithm has high calculation efficiency, but its accuracy is poor

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