Abstract:
-With recent developments in power electronic technology, high-voltage direct current (HVDC) transmission systems have emerged as a viable option for power transmission, mainly across long distances. In this paper, we proposed five terminal HVDC systems as more than two terminals. Multi-terminal high-voltage DC systems are appealing methods for linking offshore wind farms to alternating current (AC) networks. While frequency is a worldwide signal in AC grids, DC voltage can be thought of as its dual in MTDC systems. Unlike frequency, however, DC voltage cannot be equal across the MTDC system. One of the major issues with MTDC systems is the control of DC voltage. Due to intermittent nature of wind, optimum regulation of MTDC systems in the presence of offshore wind farms to minimize MTDC system loss while considering scheduled electricity is a difficulty. Here we considered the control methods of voltage margin and voltage droop methods. The VMM is considering at the cable to ground fault in the middle of a DC cable and VDM is consider at the cable to ground fault very close to a converter. A comparative analysis of control methods with a sliding mode control, the system response is fast and with very small overshoot. Effectiveness of the approach proposed is demonstrated by simulations performed with MATLAB/SIMULINK.
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