Reliability evaluation of large-scale hybrid AC/DC grids based on SOCP load shedding model

Hybrid AC/DC grids are developing steadily in China. With increasing proportion, their reliability brings greater impact on planning and operation of power systems. Aiming to evaluate reliability of large-scale hybrid AC/DC grids accurately and efficiently, a reliability evaluation method is proposed based on SOCP load shedding model and Monte Carlo simulation. Linear steady-state models of converters and reliability models of individual components in hybrid AC/DC grids are presented. With both active and reactive power in AC systems and converters considered, an optimal load shedding model based on SOCP is proposed. In a case study, the proposed reliability evaluation method is applied in a modified two-area IEEE RTS-96 test system to verify its effectiveness. Numerical tests show that reliability results would be underestimated if not considering impact of hybrid AC/DC system. The proposed method is suitable for practical application in large-scale hybrid AC/DC grid.