Steady-state power system analysis revisited for hybrid AC–DC grids

DC power systems can improve the efficiency of electricity conveyance and offer greater flexibility in integrating renewable generation. DC power systems were once restricted by an inability to transform voltage. They are being reconsidered with the increasing capabilities of power electronic converters. Challenges remain, especially in areas of planning, design, operation, protection and control. This work presents an overview of steady-state power system analysis to further facilitate adoption. In particular, numerical methods for power-flow analysis, short-circuit analysis, static voltage stability analysis and harmonic analysis are revisited for DC and hybrid AC–DC grids. These four types of analysis simulate power systems by employing linear and nonlinear numerical methods. Linear methods are summarised for short-circuit analysis in AC systems. However, adopting a unified short-circuit analysis for hybrid AC–DC grids requires nonlinear analysis. Nonlinear methods are systematically organised for power-flow analysis, and is expanded for the complexities of static voltage stability analysis and harmonic analysis. Lastly, further research is recommended to encourage greater robustness, generality, scalability and efficiency in steady-state power system analysis.