Hi, need to submit a 2000 words paper on the topic Light High Voltage Direct Current Systems.

Hi, need to submit a 2000 words paper on the topic Light High Voltage Direct Current Systems. The power flow through the HVDC link can be controlled independently of the phase angle between the source and load hence can stabilize a network against disturbances due to rapid changes in power. The Light High Voltage Direct Current (HVDC) system also allows power transfer between grid systems running at varied frequencies, such as 50 Hz and 60 Hz. This improves the stability and economy of each grid, allowing the exchange of power between incompatible networks.

The history of the Light High Voltage Direct Current (HVDC) systems dates back to the 1930s. This technology bases its originality in Sweden and Germany. Early commercial installation included the one for the Soviet Union in 1951 between Moscow and Kashira, and the 100 kV, 20 MW System between Gotland and Sweden ( Tang, Pg. 35).

With modern technology, smaller HVDC systems have been made economical. This has been managed through the development of higher-rated Insulated -gate bipolar transistors (IGTBs), gate turn-off thyristors (GTO), and integrated gate commutated thyristors. The manufacture of this is called ABB Group. The company terms this concept as HVDC light ( Bollen, Pg. 85).

The application and use of the HVDC systems have been extended to blocks as small as few tens of Megawatts and the lines are short as few kilometers of an overhead line. A current installation includes HVDC PLUS and HVDC Maxine. These two applications are based on variants of converter called Modular Multilevel Converter (MMC).

The Modular Multilevel Converter (MMC) has the advantage that they allow harmonic filtering equipment’s to be reduced and eliminated all together. Comparing the HVDC Harmonic filters and the harmonic filters of the typical power lines commutated converter stations. the harmonic filters of the ordinary lines cover nearly half of the station area.