Steady-state performance analysis method of DC microgrid based on energy storage system

Abstract

The invention discloses a DC micro-grid steady-state performance analysis method based on an energy storage system. The method comprises the following steps: respectively establishing a mixed-potential function model under a charging mode and a mixed-potential function model under a discharging model in a DC micro-grid system based on the characteristics of the DC micro-grid system in isolated island operation; respectively performing steady-state performance analysis based on the constructed mixed-potential function model and the stability theorem to obtain the stability conditions of the energy system under the charging mode and the discharging mode; regulating the parameter setting of the energy storage system according to the obtained stability conditions, and the controlling the stable operation of the DC micro-grid system. The DC micro-grid steady-state performance analysis method based on the energy storage system not only can conveniently and practically realize the elimination of the negative impedance characteristic of the constant power load, but also cannot cause the extra cost; and the realization is easy.

Description

technical field [0001] The present invention relates to the related technical field of DC micro-grid operating in an isolated island, in particular to a method for analyzing the steady-state performance of a DC micro-grid based on an energy storage system. Background technique [0002] In a DC microgrid system, refer to figure 1 As shown, it is a parallel dendritic DC microgrid topology. It can be seen from the figure that most of the loads are connected to the DC bus through a power electronic converter, that is, a load converter. When the load converter is under closed-loop control, the load and the load converter as a whole present a constant power load (Constant power loads, CPLs), when the bus voltage disturbance occurs in the DC microgrid system operating in an island, if the design is improper, the negative impedance characteristic presented by the constant power load is equivalent to introducing a positive feedback to the system, continuously amplifying the disturba...

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Problems solved by technology

The former method will affect the normal working performance of the load, and the latter method needs to change the system hardware structure, which is too expensive for the existing equipment

[0004] Therefore, in the process of implementing the present application, the applicant found that the prior art has at least the following defects: the current method of eliminating the negative impedance characteristic of the constant power load either affects the work performance, or the cost is too high, and it is not convenient and practical to implement

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