Simulating the Power Electronics-Dominated Grid using Schwarz-Schur Complement based Hybrid Domain Decomposition Algorithm

This paper presents a new two stage hybrid domain decomposition algorithm that aims to accelerate the analysis and dynamic simulations of power systems with high levels of renewables, which can be computationally intensive. The algorithm employs a Schwarz-based technique on the first level of the decomposition to break down the problem to several sub-systems using relaxation on the variables of the boundaries. next, each sub system is for the second time divided to sub-domains which can be calculated independently utilizing the Schur complement technique. Convergence will be confirmed at both levels to check the parallelized implementation of the sub-systems produces same outcomes as the original problem. To assess the effectiveness and applicability of the proposed method for implementation of large scale and very large scale power systems, it is performed on an IEEE9bus system while a solar PV farm replaces one synchronous generator connected by a grid-forming inverter with an admittance-control method. As traditional dual loop grid-forming inverter are not stable when connected to a stronger grid with a small grid inductance, a virtual inductance approach is used to increase the equivalent inductance which is connected to the grid and improve stability.