A multi-terminal power flow control method for next-generation DC power network

Abstract

DC power networks with introduction of distributed generation (DG) and energy storage (ES) systems have been drawing much attention in recent years. To control power flows in DC power networks, voltage of each terminal is usually an only controllable variable. Therefore, implementation of control method is generally simple, but it lacks flexibility particularly when the structure of the power network is complicated. To overcome the problem, a more flexible power flow control method that includes a power flow controller implemented on the distributed line has been proposed. The controller makes additional voltage differences on the distribution line and realizes bidirectional and flexible power flow control. In this paper, we consider DC power networks with complicated connections of DG and ES systems. For implementing simple and intuitive power flow control, we propose a multi-terminal power flow control method that consists of a multi-terminal power flow controller (MTPFC) and a compensation node for MTPFC. The control method makes the DC power network simpler and enables to realize flexible and robust power flow control. The effectiveness and the feasibility of the proposed control method are validated by experimental studies.