The International Journal of Research in Engineering Technology and Management (IJRETM)
In this paper, overview of HVDC system is given. HVDC system has many advantages over AC system such as bulk power delivery, lower cost, minimization of losses etc. For HVDC applications, thyristors are often placed in series and parallel to achieve the current and voltage ratings that are required. In the modern day, there is a choice between thyristor based converters and Insulated-Gate Bipolar Transistors (IGBT's). The IGBT is semiconductor device, with full control over switching the device on and off. This brings advantages in the form of advanced control of the HVDC valve, allowing the converter station to become more flexible.