Research Scholar , Indian Institute of Technology Bombay
Power Electronics Applications
My research is mainly focusing on the application of power electronics to high voltage direct current transmission applications. This improves stability and reliability of the power grid system. This also reduces the cost of systems for high power transmissions.
Abstract: This paper presents a complete shut‐down control scheme for modular multilevel converter‐based high‐voltage direct current (MMC‐HVDC) transmission systems for scheduled shut‐down scenario. The shut‐down control scheme is divided into three parts according to the discharge mechanism: the energy feedback stage, the controllable energy dissipation stage, and the uncontrollable energy dissipation stage. To make the best use of the sub‐module (SM) capacitor energy, the SM capacitor voltage is reduced by modifying the modulation strategy in the energy feedback stage. Therefore, some part of the SM capacitor energy can be fed back into the connected alternating current systems. In the controllable energy dissipation stage, the SM capacitor energy is mostly consumed by the direct current line. Lastly, the SM capacitor is discharged through the SM internal resistor in the uncontrollable energy dissipation stage. The case studies are performed on a two‐terminal 400 MW/±200 kV MMC‐HVDC system. From the simulation results, it is noted that the MMC‐HVDC system can be rapidly and reliably discharged without any severe over‐currents or over‐voltages, which proves the feasibility of the proposed control scheme. Copyright © 2015 John Wiley & Sons, Ltd.
Pub.: 14 Jul '15, Pinned: 29 Jul '17
Abstract: In high voltage direct current (HVDC) transmission system, modular multilevel converter (MMC) is not satisfactory to maintain the balance of the capacitor voltage and doesn’t have the DC side fault ride-through capability. This paper presents that the MMC bridge arm consisting of half bridge module and clamping double sub module in series can reduce the loss of steady state operation and the amount of components. The repetitive predictive control is proposed to suppress the circulation current and balance the capacitor voltage based on the topology of MMC. A related model is built in the PASAD/EMTDC software environment and a repetitive predictive control strategy is developed. The simulation results show that the proposed system not only has the DC side fault ride-through capability, but also carries out the capacitor voltage balancing task and minimizes the circulating currents.
Pub.: 24 Mar '16, Pinned: 29 Jul '17