Reliability assessment method for hybrid AC-DC distribution network with flexible substation

Abstract

An embodiment of the present invention provides a method for evaluating the reliability of a hybrid AC / DC distribution network including a flexible substation. The method includes: obtaining the network topology and component reliability parameter values ​​of the distribution network, and determining the reliability parameters of the distributed power supply DG; constructing a power electronic transformer reliability model according to the network topology of the distribution network; Whether to meet the load demand alone, establish a multi-source fault tree or a single-source fault tree corresponding to the load; according to the minimum cut set theory, use the multi-source fault tree or single-source fault tree to calculate the reliability index of each load in the distribution network ; Calculate the reliability index of the distribution network according to the reliability index of each load in the distribution network. The invention solves the problem of distribution network reliability evaluation when power electronic transformer equipment that has not yet been commercially operated is applied to a flexible substation, and provides technical support for the feasibility study, planning and design of the flexible substation project.

Description

Technical field [0001] The present invention relates to the technical field of distribution networks, and more particularly to a reliability assessment method of a mixed alternating flow distribution network containing a flexible substation. Background technique [0002] As the energy development and utilization technology matures, the proportion of cleaning energy in the power source side wind power, photovoltaic, and the proportion of the power supply structure is gradually increased. At the same time, the amount of load in the electricity side, the electrical load of the electric vehicle, such as the computer, data center, is increased, and the charge and discharge bidirectional load formed by the electric motor vehicle industry driven by green traffic has occurred. In order to deal with the power generation fluctuation caused by natural resources such as scenery, the harmonics generated by the DC load on the AC grid are reduced, and the power grid needs to be installed, the f...

AI Technical Summary

Problems solved by technology

The resulting problems are: the increase of AC-DC converter conversion equipment in the power grid, including DC / AC or AC / DC conversion devices of different voltage levels, and the new additions such as DG (distributed generation, distributed power generation) in the power grid ), energy storage and other new equipment, these equipment also have their own output characteristics, resulting in a more complex power distribution network structure and more difficult coordinated control

In the past, the reliability analysis of flexible power equipment such as DC transmission and conversion equipment was based on the analysis and calculation based on the component-level reliability theory model, which was too ideal; in addition, the voltage level of flexible power equipment was high, at least 10kV and above, and the topological Complex, there are hundreds of IGBTs (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor), and the equipment reliability calculated based on a large number of component-level reliability theoretical models is prone to large errors. There is actually a large distance in the project

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