BFO Based Control of Multiterminal VSC-HVDC for Voltage Deviation

Multi-Terminal High-Voltage Direct Current (MTDC) transmission system has become an auxillary for transmitting power especially over long distances. .In AC grids, frequency are a global variable and for MTDC systems, DC voltage can be considered as it’s dual. Unlike frequency, DC voltage cannot be equal across the MTDC system. The Control of DC voltage in MTDC systems is one of the important challenges. The dynamic of MTDC system is very fast, DC voltage control methods cannot rely only on remote information. Therefore, they can work based on either local information or a combination of local and remote information. The BFO algorithm is used to maintain the constant DC voltage operation during load switchings, step changes in power demand and also provides secured power to passive loads during loss of a DC voltage by regulating VSC-HVDC terminal without the use of communication. In this paper, the BFO algorithm along with Voltage Droop Method (VDM) is implemented in MATLAB/SIMULINK and it used to maintain the electromechanical stability of Multi-Terminal VSC-HVDC system.