Renewable Energy Accommodation Optimization Model Considering DC Tie Line Operation Conditions

With the increasing scale of renewable energy in China, how to optimize the power regulation capacity of DC tie lines has become an important challenge for renewable energy accommodation in interconnected power grids. Therefore, this paper establishes a stair-like power optimization model for DC tie lines. This model can meet the constraints of conventional generating units and renewable energy generating units in the sending and receiving systems. The model can also meet the constraints of DC tie line, including DC power stair-like regulation, the times of regulation, constant daily exchange power and no reverse power regulation in short time, which can not only improve the flexibility of the DC tie line regulation, but also meet the safety requirements of the practical engineering operation. In addition, this model can take into account multiple DC tie lines of multiple interconnected power grids and the load complementarities in the sending and receiving systems, further promoting the accommodation of renewable energy in a larger space. Finally, based on the practical data of a provincial interconnected power grid in China, the effectiveness of this model was verified by the before-and-after optimized comparison by means of DC tie line power, conventional generating units output and proportion of renewable energy abandonment of wind and photovoltaic.