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Kamalesh Hatua

Bio: Kamalesh Hatua is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topic(s): Insulated-gate bipolar transistor & Gate driver. The author has an hindex of 21, co-authored 82 publication(s) receiving 1516 citation(s). Previous affiliations of Kamalesh Hatua include Indian Institute of Science & North Carolina State University.
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Journal ArticleDOI
Abstract: Medium-voltage (MV) SiC devices have been developed recently which can be used for three-phase MV grid tie applications. Two such devices, 15 kV SiC insulated-gate bipolar transistor (IGBT) and 10 kV SiC MOSFET, have opened up the possibilities of looking into different converter topologies for the MV distribution grid interface. These can be used in MV drives, active filter applications, or as the active front end converter for solid-state transformers (SSTs). The transformerless intelligent power substation (TIPS) is one such application for these devices. TIPS is proposed as a three-phase SST interconnecting a 13.8 kV distribution grid with a 480 V utility grid. It is an all SiC device-based multistage SST. This paper focuses on the advantages, design considerations, and challenges associated with the operation of converters using these devices keeping TIPS as the topology of reference. The efficiency of the TIPS topology is also calculated using the experimentally measured loss data of the devices and the high-frequency transformer. Experimental results captured on a developed prototype of TIPS along with its measured efficiency are also given.

224 citations

Journal ArticleDOI
TL;DR: A simple active damping technique is proposed for lossless damping of vector-controlled ac motor drives with an LC filter and is carried out in the three-phase domain for better accuracy of the control.
Abstract: For longer life of alternating-current (ac) machines, it is desirable to feed them by sinusoidal voltages. This can be achieved by connecting an LC filter between the voltage source inverter and the motor. However, the LC filter creates unwanted oscillation at system resonant frequency. A resistance connected in series with the capacitor is a solution to damp out the resonant-frequency oscillation, but this damping technique increases loss in the system. In this paper, a simple active damping technique is proposed for lossless damping of vector-controlled ac motor drives with an LC filter. In the proposed technique, the resistance drop is emulated in the control using the terminal motor voltages. The proposed technique is carried out in the three-phase domain for better accuracy of the control. The proposed technique neither affects the dynamic response of the drive nor changes the design of the standard vector control loops. Results from experimental ac motor drives are presented.

93 citations

Journal ArticleDOI
Abstract: The solid-state transformer (SST) is a promising power electronics solution that provides voltage regulation, reactive power compensation, dc-sourced renewable integration, and communication capabilities, in addition to the traditional step-up/step-down functionality of a transformer. It is gaining widespread attention for medium-voltage (MV) grid interfacing to enable increases in renewable energy penetration, and, commercially, the SST is of interest for traction applications due to its light weight as a result of medium-frequency isolation. The recent advancements in silicon carbide (SiC) power semiconductor device technology are creating a new paradigm with the development of discrete power semiconductor devices in the range of 10-15 kV and even beyond-up to 22 kV, as recently reported. In contrast to silicon (Si) IGBTs, which are limited to 6.5-kV blocking, these high-voltage (HV) SiC devices are enabling much simpler converter topologies and increased efficiency and reliability, with dramatic reductions of the size and weight of the MV power-conversion systems.

90 citations

Proceedings ArticleDOI
Kamalesh Hatua1, Sumit Dutta1, Awneesh Tripathi1, Seunghun Baek1  +2 moreInstitutions (1)
01 Nov 2011-
Abstract: Basic power topology for a Solid State Transformer (SST) with new 15kV SiC IGBT devices is discussed. It is difficult to build high efficient, light weight, magnetically isolated solid state transformer for high voltage (13.8 kV) grid connectivity with existing Si 6.5kV rated IGBTs and diodes. Existing state of the art high voltage (6.5kV), high speed power devices (IGBT) cause considerable amount of loss (switching and conduction loss). With the advent of SiC devices these limitations are largely mitigated and this provides the motivation for new power topologies. The targeted efficiency of the proposed SST is 98%.Simulation results for a 1 MVA proposed SST topology is presented.

73 citations

Proceedings ArticleDOI
12 Nov 2012-
Abstract: Silicon Carbide (SiC) devices and modules have been developed with high blocking voltages for Medium Voltage power electronics applications. Silicon devices do not exhibit higher blocking voltage capability due to its relatively low band gap energy compared to SiC counterparts. For the first time, 12kV SiC IGBTs have been fabricated. These devices exhibit excellent switching and static characteristics. A Three-level Neutral Point Clamped Voltage Source Converter (3L-NPC VSC) has been simulated with newly developed SiC IGBTs. This 3L-NPC Converter is used as a 7.2kV grid interface for the solid state transformer and STATCOM operation. Also a comparative study is carried out with 3L-NPC VSC simulated with 10kV SiC MOSFET and 6.5kV Silicon IGBT device data.

63 citations

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Journal ArticleDOI
Emil Levi1Institutions (1)
TL;DR: An attempt is made to provide a brief review of the current state of the art in the area of variable-speed drives, addressing the reasons for potential use of multiphase rather than three-phase drives and the available approaches to multiphases machine designs.
Abstract: Although the concept of variable-speed drives, based on utilization of multiphase machines, dates back to the late 1960s, it was not until the mid- to late 1990s that multiphase drives became serious contenders for various applications. These include electric ship propulsion, locomotive traction, electric and hybrid electric vehicles, ldquomore-electricrdquo aircraft, and high-power industrial applications. As a consequence, there has been a substantial increase in the interest for such drive systems worldwide, resulting in a huge volume of work published during the last ten years. An attempt is made in this paper to provide a brief review of the current state of the art in the area. After addressing the reasons for potential use of multiphase rather than three-phase drives and the available approaches to multiphase machine designs, various control schemes are surveyed. This is followed by a discussion of the multiphase voltage source inverter control. Various possibilities for the use of additional degrees of freedom that exist in multiphase machines are further elaborated. Finally, multiphase machine applications in electric energy generation are addressed.

1,559 citations

Journal ArticleDOI
Emil Levi1, Radu Bojoi2, Francesco Profumo2, Hamid A. Toliyat3  +1 moreInstitutions (4)
Abstract: The area of multiphase variable-speed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Research has been conducted worldwide and numerous interesting developments have been reported in the literature. An attempt is made to provide a detailed overview of the current state-of-the-art in this area. The elaborated aspects include advantages of multiphase induction machines, modelling of multiphase induction machines, basic vector control and direct torque control schemes and PWM control of multiphase voltage source inverters. The authors also provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as an overview of the approaches to the design of fault tolerant strategies for post-fault drive operation, and a discussion of multiphase multi-motor drives with single inverter supply. Experimental results, collected from various multiphase induction motor drive laboratory rigs, are also included to facilitate the understanding of the drive operation.

1,258 citations

01 Jan 2016-
TL;DR: The design of analog cmos integrated circuits is universally compatible with any devices to read and is available in the book collection an online access to it is set as public so you can download it instantly.
Abstract: Thank you very much for downloading design of analog cmos integrated circuits. Maybe you have knowledge that, people have look hundreds times for their favorite novels like this design of analog cmos integrated circuits, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some malicious virus inside their laptop. design of analog cmos integrated circuits is available in our book collection an online access to it is set as public so you can download it instantly. Our digital library saves in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the design of analog cmos integrated circuits is universally compatible with any devices to read.

659 citations

Journal ArticleDOI
Xu She1, Alex Q. Huang1, Rolando Burgos2Institutions (2)
Abstract: The solid-state transformer (SST), which has been regarded as one of the 10 most emerging technologies by Massachusetts Institute of Technology (MIT) Technology Review in 2010, has gained increasing importance in the future power distribution system. This paper presents a systematical technology review essential for the development and application of SST in the distribution system. The state-of-the-art technologies of four critical areas are reviewed, including high-voltage power devices, high-power and high-frequency transformers, ac/ac converter topologies, and applications of SST in the distribution system. In addition, future research directions are presented. It is concluded that the SST is an emerging technology for the future distribution system.

652 citations

Journal ArticleDOI
Donghua Pan1, Xinbo Ruan1, Chenlei Bao1, Weiwei Li1  +1 moreInstitutions (1)
Abstract: This paper investigates the capacitor-current-feedback active damping for the digitally controlled LCL-type grid-connected inverter. It turns out that proportional feedback of the capacitor current is equivalent to virtual impedance connected in parallel with the filter capacitor due to the computation and pulse width modulation (PWM) delays. The LCL-filter resonance frequency is changed by this virtual impedance. If the actual resonance frequency is higher than one-sixth of the sampling frequency (fs/6), where the virtual impedance contains a negative resistor component, a pair of open-loop unstable poles will be generated. As a result, the LCL-type grid-connected inverter becomes much easier to be unstable if the resonance frequency is moved closer to fs/6 due to the variation of grid impedance. To address this issue, this paper proposes a capacitor-current-feedback active damping with reduced computation delay, which is achieved by shifting the capacitor current sampling instant towards the PWM reference update instant. With this method, the virtual impedance exhibits more like a resistor in a wider frequency range, and the open-loop unstable poles are removed; thus, high robustness against the grid-impedance variation is acquired. Experimental results from a 6-kW prototype confirm the theoretical expectations.

472 citations

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Author's H-index: 21

No. of papers from the Author in previous years

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