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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 topics: Insulated-gate bipolar transistor & Gate driver. The author has an hindex of 21, co-authored 82 publications receiving 1516 citations. Previous affiliations of Kamalesh Hatua include Indian Institute of Science & North Carolina State University.


Papers
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Journal ArticleDOI
TL;DR: A switched current source-based AGD is designed and extensively tested in a 50-kVA voltage source inverter made with SiC MOSFET power modules and the control methodology is discussed and the experimental results are presented.
Abstract: Silicon carbide (SiC) MOSFETs are viable alternatives for silicon (Si) insulated-gate bipolar transistors (IGBTs). However, direct retrofitting of SiC MOSFETs in Si IGBT-based converters is not feasible due to the presence of a higher amount of parasitic inductance. A large voltage and current overshoot along with oscillation are noticed in such attempts as SiC MOSFETs switch very fast. An active gate driver (AGD) can meet the conflicting requirements of faster switching speed and lower overshoot and ringing. A switched current source-based AGD is designed and extensively tested in a 50-kVA voltage source inverter made with SiC MOSFET power modules. The control methodology is discussed and the experimental results are presented in this article.

29 citations

Proceedings ArticleDOI
01 Dec 2016
TL;DR: In this article, the effects of parasitic inductance on the switching performance of SiC MOSFET have been mathematically modeled and verified with experimental results in a double pulse test circuit.
Abstract: 1200 V SiC MOSFET is a viable alternative for state of the art Si IGBTs due to its superior switching performances. However, high di/dt and dv/dt during the switching transients worsen the switching performance of the SiC MOSFET due to the presence of parasitic inductances in the inverter layout. They cause undesired overshoot and oscillations in the device voltage and current. They also increase switching loss. These detrimental effects are required to be analyzed in detail to develop an efficient SiC MOSFET based inverter. In this paper, the effects of parasitic inductances on the switching performance of SiC MOSFET have been mathematically modeled. The modeling is verified with experimental results in a double pulse test circuit. Interestingly, the modeling reveals detrimental switching modes those can arise in the case of SiC MOSFET. They are highly unlikely to be observed in the case of Si IGBT.

28 citations

Journal ArticleDOI
TL;DR: A new power topology for LCI-fed induction motor drive for medium-voltage drive application is proposed and a new induction machine (active-reactive induction machine) with two sets of three-phase winding is introduced as a drive motor.
Abstract: Till date load-commutated inverter (LCI)-fed synchronous motor drive configuration is popular in high power applications (>;10 MW). The leading power factor operation of synchronous motor by excitation control offers this simple and rugged drive structure. On the contrary, LCI-fed induction motor drive is absent as it always draws lagging power factor current. Therefore, complicated commutation circuit is required to switch off thyristors for a current source inverter (CSI)-driven induction motor. It poses the major hindrance to scale up the power rating of CSI-fed induction motor drive. A new power topology for LCI-fed induction motor drive for medium-voltage drive application is proposed. A new induction machine (active-reactive induction machine) with two sets of three-phase winding is introduced as a drive motor. The proposed power configuration ensures sinusoidal voltage and current at the motor terminals. The total drive power is shared among a thyristor-based LCI, an insulated gate bipolar transistor (IGBT)-based two-level voltage source inverter (VSI), and a three-level VSI. The benefits of SCRs and IGBTs are explored in the proposed drive. Experimental results from a prototype drive verify the basic concepts of the drive.

25 citations

Proceedings ArticleDOI
28 Oct 2013
TL;DR: In this paper, the authors proposed the solutions for some of the practical implementation problems of the control algorithm for the three-phase dual active bridge (DAB) Y : Y/Δ composite topology.
Abstract: Three-phase Dual Active Bridge (DAB) Y : Y/Δ composite topology offers advantage of nearly sinusoidal converter-currents without pulse-width modulation, which can be utilized for D-Q mode control implementation. D-Q control is smooth and regulates power-factor of DAB which ensures zero voltage switching (ZVS) operation of the DAB converter at wide-range loading conditions. A practical DAB high-frequency transformer has certain limitations like small leakage-inductance, limited magnetizing-inductance and unwanted parasitic-capacitance's which distort the primary-side currents at the rated high-voltage because primary inter-turn capacitance is high in per-unit for a real 100kW transformerdesign. This problem can be solved by using secondary currents and estimated magnetizing current to emulate primary-currents for D-Q control. Parasitic are introduced in the LV TIPS set-up by adding lumped elements to emulate real HV-transformer with objective to test the controls in worst case scenario. This paper proposes the solutions for some of the practical implementation problems of the control algorithm for the DAB.

24 citations

Journal ArticleDOI
TL;DR: In this paper, a novel technique is proposed to extend the region of zero voltage switching (ZVS) of a dual active bridge (DAB) dc-dc converter using an auxiliary series injection transformer.
Abstract: In this paper, a novel technique is proposed to extend the region of zero voltage switching (ZVS) of a dual active bridge (DAB) dc–dc converter using an auxiliary series injection transformer. The series voltage injection by the series transformer helps us to maintain ZVS by controlling the reactive power flow through the main converter of the DAB. A model for the series compensation is developed to compute the phase angle of the series voltage to obtain the optimum efficiency over the entire region of operation. The proposed technique is validated through simulations and the corresponding converter loss reduction is presented. The system is implemented on a high-voltage hardware with $6$ kV- $270$ V DAB using 10-kV SiC mosfet -based converter in the primary and 1200-V SiC mosfet on the secondary side of the transformer and the corresponding results are presented.

23 citations


Cited by
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Journal ArticleDOI
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.

1,683 citations

Journal ArticleDOI
TL;DR: A detailed overview of the state-of-the-art in multiphase variable-speed motor drives can be found in this article, where the authors provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as the approaches to the design of fault tolerant strategies for post-fault drive operation.
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.

1,445 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.

912 citations

Journal ArticleDOI
TL;DR: In this article, the authors present a systematical technology review essential for the development and application of SST in the distribution system, including high-voltage power devices, high-power and high-frequency transformers, ac/ac converter topologies, and future research directions.
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.

897 citations

Journal ArticleDOI
TL;DR: In this article, a capacitor-current-feedback active damping with reduced computation delay is proposed, which is achieved by shifting the capacitor current sampling instant towards the PWM reference update instant.
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.

598 citations