Small Signal Stability Analysis of Detailed DC Grids Network Model

DC grids based on VSC-HVDC could be a competitive and an attractive option for many applications such as renewable energy interconnection or for power supply to large metropolitan areas for many reasons. A detailed 121st order multiple-input multiple output small-signal dynamic model of a DC grid network is presented in this paper. It contains control systems, and detailed representations of the AC and DC side. Aspects such as DC voltage droop control, the cut off frequency of the DC voltage feedback filters are discussed in detail. An eigenvalues stability study is used to find the optimum values of the droop gains and the cut off frequency of the DC voltage feedback filters. The model accuracy is verified using detailed PSCAD simulation. Testing on the detailed simulator PSCAD/EMTDC is carried out all over to validate the conclusions that obtained from analytical studies.