Technical feasibility of Power Flow Controllers for HVDC grids

Abstract

Power Flow Controllers (PFCs) or Current Flow Controllers (CFCs) are expected to be required in future High Voltage Direct Current (HVDC) grids to aid in the current distribution. This work analyses the feasibility of this kind of devices from the implementation point of view. First, the needs of a PFC as a medium voltage converter floating at high voltage are assessed. Then, the paper discusses the challenges to implement one of these converters, such as the sizing of the power electronic elements, cooling management, insulation from ground, etc. Most of them are already tackled in other existing devices in the field of high voltage. Powering the PFC semiconductors gate-drivers and other auxiliary systems at high potential is seen as a particular point to take into account when building the device.

Methodology to obtain the specifications and perform the sizing of a power flow controller for meshed HVDC grids

“…Once the PFC structure and variant is selected, the sizing of the power electronic components of the PFC (IGBTs, diodes, inductor and capacitors) is performed for normal operation. The additional components as bypass switches, protection equipment, cooling system and control systems are not analyzed here, but their technical feasibility has been discussed in [9]. Fig.…”