Indian Institute of Technology Bombay

About: Indian Institute of Technology Bombay is a education organization based out in Mumbai, India. It is known for research contribution in the topics: Population & Thin film. The organization has 16756 authors who have published 33588 publications receiving 570559 citations.

A Multilevel Transformerless Inverter Employing Ground Connection Between PV Negative Terminal and Grid Neutral Point

Abstract: For the safe operation of transformerless grid connected photovoltaic (PV) inverters, the issue of common mode (CM) leakage current needs to be addressed carefully. In this paper, a novel multilevel transformerless inverter topology is proposed, which completely eliminates CM leakage current by connecting grid neutral point directly to the PV negative terminal, thereby bypassing the PV stray capacitance. It provides a low-cost solution consisting of only four power switches, two capacitors, and a single filter inductor. As compared to half-bridge topologies, with this inverter a minimum of 27% and maximum of 100% more output voltage is obtained for the same dc-link voltage. The proposed inverter is analyzed in detail and its switching pattern to generate multilevel output while maintaining the capacitor voltage is discussed. Simulations and experiments results confirm the feasibility and good performance of the proposed inverter.

Energy Management in Smart Distribution Systems With Vehicle-to-Grid Integrated Microgrids

Abstract: In modern electric power systems, plug-in electric vehicle (PEV) with vehicle-to-grid (V2G) potential are becoming reliable and flexible resources for energy balancing under varying energy supply and demand scenarios. In this evolving paradigm, designing energy management strategies for feasible and cost-effective utilisation of V2G is one of the several challenges faced by the utility operators and regulators. This paper proposes two energy management strategies to effectively utilize V2G potential of PEVs in managing energy imbalances in grid-connected microgrids. The contributions of this paper are in twofold. First, it proposes a novel bidding strategy for PEVs offering V2G by including the projected battery degradation cost to integrate them into microgrid operation. Second, two energy management strategies are proposed for inclusion of V2G into the microgrid operation based on the forecast accuracy on energy supply and demand, and market prices. The proposed V2G integration strategies are implemented using a multi-agent system developed in Java agent development framework and applied to a microgrid case study system. The simulation results and their analysis show that V2G can be used to maximum depth of discharge levels if the electricity price variation is high and battery cost of PEVs is low.

$\beta$ -Ga 2 O 3 Delta-Doped Field-Effect Transistors With Current Gain Cutoff Frequency of 27 GHz

Abstract: As an ultra-wide bandgap semiconductor, $\beta $ -Ga2O3 has attracted great attention for high-power, high-voltage, and optoelectronic applications. However, until now, high-frequency performance of gallium oxide devices has been limited to relatively low current gain cutoff frequencies below 5 GHz. Here, we show that highly localized delta-doping designs can enable high-sheet-charge density to enable devices with short gate lengths that allow high-frequency operation. Field-effect transistors with a gate length of 120 nm on such delta-doped $\beta $ -Ga2O3 are reported here with extrinsic unity current gain frequency of 27 GHz. The device has a peak drain current of 260 mA/mm, transconductance (gm) of 44 mS/mm, and three-terminal off-state breakdown voltage of 150 V. These results demonstrate that the potential of $\beta $ -Ga2O3 for future RF and millimeter-wave device applications.