Research on a novel multi-port DC power flow controller and its control strategies

Abstract

A direct current power flow controller is a key device for regulating steady-state power flow in multi-terminal DC （direct current） grids. In response to the limitations of existing DC power flow controllers， a novel multi-port DC power flow controller is designed by incorporating a cascaded submodules with adjustable DC output voltage in a circular branch. Firstly， the topology and operation principles of the proposed controller are explained. Then， its control strategies and parameter selection methods are introduced. Finally， the performance of the DC power flow controller is validated through electromagnetic transient simulations on a five-terminal DC grid with eight DC lines. The results indicate that the proposed controller can simultaneously regulate power flow on multiple DC lines connected to the same DC bus， demonstrating advantages of modularity and easy scalability.

Keywords

• multi-terminal dc grid
• multi-port dc power flow controller
• cascaded submodules
• power balance
• control strategy