Research on Power Flow and Flexible Control in DC Power System

The DC distribution system has advantages over AC systems on power losses, control complexity, compatibility to DGs (Distributed Sources) and so on. The basic power flow problem in DC system is different from AC system in mathematical domain, bus types and component models. To construct the foundation of DC power system analysis, this paper analyzes the power flow problems in DC distribution system first, including bus types, power flow equations, Jacobian matrix and so on. It is pointed out that voltage regulation in DC power system only needs enough power capacity instead of generator with excitation system like AC system. Then, based on the DC bus voltage regulation property, the power flow path control and virtual topology reconfiguration technologies is proposed. The corresponding equivalent Jacobian matrixes are presented. Those technologies reveal that the DC power system can achieve much higher flexibility in power flow control. At last, simulation verification with MATLAB/SIMULINK is presented.