Alternating Iterative Power-Flow Algorithm for Hybrid AC–DC Power Grids Incorporating LCCs and VSCs

AC–DC power-flow calculation is the basis for studying HVDC systems. Since traditional iterative methods need many alternative iterations and have convergence problems, this paper proposes an alternating algorithm hybrid power grids incorporating line-commutated converters (LCCs) voltage source (VSCs). Firstly, incorporates converter interface model into AC side, considering influence of DC side on establishes AC-augmented Jacobian matrix with LCC/VSC equation variables. Then, according to type converter, control mode, grid strategy, a under various modes established realizing decoupling LCCs VSCs. The accuracy effectiveness improved are evaluated using modified IEEE 57 bus networks CIGRE B4 test system. applicable considers reasonable adjustment variable constraints operating modes.