Three-phase power flow correction method for power distribution network containing distributed power sources

Abstract

The invention discloses a three-phase power flow correction method for a power distribution network containing distributed power sources. The method specifically comprises the following steps that a distributed power source three-phase model is constructed; a power distribution network three-phase system model containing the distributed power sources is established; nodes and branches in the power distribution network three-phase system model are numbered; three-phase load parameters of all the nodes in the power distribution network are stored according to the numbering sequence of the nodes, and three-phase impedance parameters of all the branches in the power distribution network are stored according to the numbering sequence of the branches; the three-phase load parameters of all the nodes and the three-phase impedance parameters of all the branches are subjected to per-unit treatment; problems existing in power flow calculation of the power distribution network containing the distributed power sources are analyzed, and the grid-connected voltage of the distributed power sources is corrected; convergence precision is selected, a power distribution network three-phase system containing the distributed power sources is subjected to three-phase forward-back substitution power flow calculation. According to the method, the characteristic that the output current and the grid-connected voltage of the distributed power source model are symmetric is considered, and a positive-sequence component of the network-side voltage is selected as the grid-connected voltage of the distributed power sources to participate in power flow calculation.

Description

technical field [0001] The invention relates to a method for correcting a three-phase power flow of a distribution network including a distributed power supply, and belongs to the technical field of power flow calculation of a distribution network of a power system. Background technique [0002] Energy and environmental issues are the focus of attention of countries all over the world. In my country, in order to achieve the national goal of "energy saving and emission reduction", the power industry has vigorously developed various renewable energy power generation on the power generation side, moving towards the direction of "low carbonization" and "zero emission" of electric energy production, which has led to wind power The rapid development of distributed power such as power generation and photovoltaic power generation. [0003] With the improvement of users' requirements for power supply reliability and power quality, the distribution network, which is a relatively weak ...

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Problems solved by technology

[0006] From the point of view of traditional power flow algorithms, forward-backward generation method and Newton-Raphson method are most widely used in distribution network power flow calculation: forward-backward generation method makes full use of the radial characteristics of distribution network, and has good convergence and low memory consumption. It is a recognized high-efficiency algorithm because of its low calculation speed and low calculation speed. However, the forward push-back generation has weak processing ability for the weak links existing in the distribution network, and it is necessary to reasonably number the nodes and branches of the distribution network; the Newton-Raphson method is theoretically suitable for all The solution of nonlinear equations is not affected by the ring network, but it has the disadvantages of sensitivity to initial values, poor convergence, large data storage, and slow calculation speed, and Newton's method uses injected power instead of injected current to obtain nonlinear equations Then iteratively solve, it is not easy to change the situation that the injected current is a positive sequence, and the model characteristics of the load distributed power supply in the actual calculation process cannot be guaranteed

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