A Solid State Transformer model for power flow calculations

•Solid State Transformer (SST) model for implementation in OpenDSS and adequate for power flow calculations.•The model does not depend on the SST configuration (e.g. the representation of the SST losses and efficiency can be used regardless of SST configuration).•The new SST model is applied to long-term simulations and to test systems of different sizes in which generation has been embedded.•The model can be easily expanded to add new control capabilities. This paper presents the implementation of a Solid State Transformer (SST) model in OpenDSS. The goal is to develop a SST model that could be useful for assessing the impact that the replacement of the conventional iron-and-copper transformer with the SST can have on the distribution system performance. Test distribution systems of different characteristics and size have been simulated during different time periods. The simulations have been carried out assuming voltage-dependent loads and considering that power flow through either the HV/MV substation transformer or any of the MV/LV distribution transformers can be bidirectional. Simulation results prove that a positive impact should be expected on voltages at both MV and LV levels, but the efficiency of current SST designs should be improved.