Design Analysis And Control Scheme For DC Power Flow In HVDC Network

As the utilization of renewable energy systems is increasing,the importance of hybrid power system is also becoming more important for power quality improvement.Mostly,these hybrid power systems utilize the Flexible AC Transmission Systems(FACTS)in combination with High Voltage Direct Current(HVDC)to increase the power flow in the network.In the FACTs family,interline power flow controller(IPFC)is applied to control the power flow between two lines.DC interline power flow controller is like an IPFC and is utilized to control power flow in two DC transmission lines.This article introduces a new method to balance power flow in the DC network by using DC interline power flow controller.In the proposed method,a topology of DC differential-mode transformer(DMT)has been proposed with a combination of bi-directional buck converter to form a variable DMT.Compared to existing methods,the proposed system is scalable,which makes it suitable for high power high voltage DC transmission systems.In this study,the analysis of the proposed topology,its design parameters,control method and a case study have been discussed.Two control methods have been proposed to achieve the desired power flow in three node dc network.Detailed Case study,with parameter design and small signal model-based compensator design has been considered to show various aspects of proposed method.Simulation results of three-terminal HVDC network are added to validate the overall system performance.The simulation and experimental results of the proposed method using a simplified resonant converter based fixed DMT have also been included to validate the proposed method...