Research on Equivalent Modeling Method of Multiple New Energy Stations for Sub/Supersynchronous Oscillation Analysis

With the increasing use of power electronics in the power system year by year, more and more new energy stations are connected to the AC system on a large scale, which also brings new stability problems such as wide-band oscillation. When carrying out detailed modeling and simulation analysis of such power systems, it will face the problem of "dimension disaster". At present, there is a relatively mature method for the internal aggregation equivalence of a single new energy station. However, it is very difficult to further aggregate equivalence for multiple stations, because there are significant differences in the parameters of units of different manufacturers and models, and the influence of electrical distance is caused by the collection of booster transformers and transmission lines in different stations. Starting from the specific analysis requirements of sub/supersynchronous oscillation, this paper adopts the frequency domain impedance method to study the equivalent method of multiple full-power converter-type new energy stations.Firstly, the frequency domain impedance characteristics and key parameters of a single new energy station are analyzed, and the key indicators of station grouping and aggregation are proposed;Secondly, the parameter calculation method of the equivalent unit is studied, and the feasibility of using one or more equivalent units to perform the multi-station equivalent value is analyzed; Finally, a specific example is established, and the feasibility of the proposed equivalent modeling method is verified by impedance analysis in the frequency domain.