A novel system operation mode with flexible bus type selection method in DC power systems

With the development of power electronics technology, the DC power system shows great advantages to improve the power system performance. However, the research on DC power system is far from enough, and there is great demand for the improvement of system flexibility and renewable energy integration ability. Thus, the new flexible system operation mode which can satisfy the requirements is of interest. This paper carefully analyzes and discusses the power flow problem of DC power systems first. Then, some new bus types are proposed to construct new system operation modes which can improve the system flexibility (includes friendly renewable energy sources integration ability and flexible power flow ability). The proposed power flow calculation method can solve the power flow problem with the new operation modes and new bus types. However, the feasibility of system operation may be broken by arbitrary selection of new bus types. Thus, the flexible bus type selection method is further proposed to select proper bus types. As a result, the system flexibility can be improved and the feasibility of system can be assured. At last, the numerical experiments results are presented to verify the effectiveness of proposed method.