Stability Analysis and Active Stabilization of DC Power Systems for Electrified Transportation Systems, Taking into Account the Load Dynamics

Power loads are often modeled as constant power loads (CPLs) for stability analysis. However, this model may be too strict, and practical power loads are not ideal CPLs. In this paper, a discrete-time modeling is applied to the model of a power load of a dc system that is composed of a source converter, an LC filter, and the power load. A stabilizer is then added to the command scheme of the source converter in order to increase the maximum stable power of the system. The model also takes into account the dynamics of the load. Simulation and experimental results are given to validate the proposed model and to demonstrate the effectiveness of the proposed stabilizer, tuning of the stabilizer parameter, and the load current controller gain.