Shrikant Misal

Bio: Shrikant Misal is an academic researcher from Indian Institute of Technology Delhi. The author has contributed to research in topics: Buck converter & Topology (electrical circuits). The author has an hindex of 2, co-authored 13 publications receiving 15 citations. Previous affiliations of Shrikant Misal include Reva Institute of Technology and Management.

Analysis of a Fourth-Order Step-Down Converter

Abstract: This article proposes a nonisolated wider step-down conversion ratio dc–dc converter having minimum phase behavior at nominal operating condition, for point-of-load applications. Compared to existing quadratic/stacked buck converter variants, the proposed topology shows effective switch utilization at low output voltages, lesser ripple content in source current, and reduced voltage/current stress on components. Time-domain analysis is formulated to anticipate the steady-state converter performance and establish design equations for L–C components. The state-space average model is derived and linearized transfer functions are evaluated to subsequently design a fixed-frequency sliding-mode controller. Step-by-step design procedure is presented to fulfil sliding surface existence, reachability, and stability conditions. Equivalent control law devised in this scheme is duly constituted from source side inductor current dynamics and load voltage error information, so it provides simple realization as well as better transient response. The distinctive features of proposed converter are studied analytically and demonstrated through experimental measurements on a laboratory prototype.

Comparative analysis of a 3-phase, 3-level diode clamped ZSI based on modified shoot through PWM techniques

Abstract: In this paper, a Z-source fed 3-phase, 3-level diode clamped inverter topology implementing modified reference and carrier based modulation techniques have been analyzed for different shoot through states of operation. Performance of the system based on respective carrier and reference frame of control has been thoroughly evaluated and simulation results pertaining to magnitudes of Total Harmonic Distortion (THD) as well as fundamental output voltage have been tabulated. From the obtained values of fundamental voltage, suitable graphs have been drawn showing its variation with shoot through factor. Results reveal that there is a serious need to formulate an optimal modulation strategy which can limit the magnitude of THD and achieve desired fundamental voltage without compromising on the efficiency. The study aids selection of best possible modulation technique for a chosen 3-phase adjustable speed drive operation implementing diode clamped inverter.

Analysis of a Fourth Order Step-Down Converter

Abstract: In this paper, a fourth-order buck converter with higher capability to step down supply voltage is proposed. Owing to low voltage gain that ideally altercates from minimum to a maximum value near unity, this converter becomes a suitable choice for interfacing high voltage DC-supply with a low voltage application at the output. Key features of this topology include lesser switching elements with minimal switch voltage stress. The steady-state analysis of converter is discussed for continuous conduction mode of inductor current and design criteria for selecting circuit components are established. In order to regulate its load voltage, a single-loop voltage mode controller has been designed making use of the state-space average model obtained using equivalent ON and OFF switching circuits. A converter prototype test circuit is designed for 42 to 12 V, 28 W rating to verify the steady-state and dynamic performance of converter using simulation and experimental studies.

Analysis of a sixth-order higher bucking converter

Abstract: In this paper, a sixth-order buck converter facilitating higher bucking operation is proposed. This topology has a step-down gain which ideally varies between 0 and 1 for respective minimum and maximum duties of operation. The effectiveness of this topology is justified with respect to voltage gain, nature of source current and input filtering requirements. A steady-state analysis has been carried out for the converter and design equations for its circuit parameters are obtained. Also, the state-space model is formulated based on switching circuits and is utilized to design an effective voltage-mode controller. Steady-state and dynamic behaviour of this topology are verified using simulation and experimental studies.

Designing Control Loops for Linear and Switching Power Supplies: A Tutorial Guide. By Christophe Basso, Artech House, 2012; 593 Pages. Price £99.00, ISBN 978-1-60807-557-7

Abstract: Loop control is an essential area of electronics engineering that today’s professionals need to master. Rather than delving into extensive theory, this practical book focuses on what you really need to know for compensating or stabilizing a given control system. You can turn instantly to practical sections with numerous design examples and ready-made formulas to help you with your projects in the field. You also find coverage of the underpinnings and principles of control loops so you can gain a more complete understanding of the material. This authoritative volume explains how to conduct analysis of control systems and provides extensive details on practical compensators. It helps you measure your system, showing how to verify if a prototype is stable and features enough design margin. Moreover, you learn how to secure high-volume production by bench-verified safety margins.

Step-Down Switched-Inductor Hybrid DC-DC Converter for Small Power Wind Energy Conversion Systems With Hybrid Storage

Abstract: This work is focused on a step-down switched-inductor hybrid dc-dc converter (SIHDC) integrated in a small power wind energy conversion system (WECS). The converter has two roles, to maintain the wind turbine at the maximum power point by controlling the electric generator loading, and to charge a high power density supercapacitor, which is part of a hybrid storage unit that also contains rechargeable batteries. The paper points out the steady-state analysis of the converter in continuous and discontinuous current modes, specific for this application. The stability investigation is presented in detail, including the influence of the electrical generator. The parameterized small-signal transfer function of the control variable derived in this paper can be used to quickly obtain the information needed to evaluate the stability of any similar WECS. A current controller was designed to achieve a stable operation in continuous current mode, and afterwards the stability was checked for discontinuous current mode. A 5kW step-down SIHDC prototype was built and extensively tested, both in laboratory, by using a wind turbine emulator, and in a small power (5kW) WECS industrial platform. Experimental results obtained under real operating conditions confirm the theoretical analysis and laboratory tests, showing that SIHDC converter is a valid solution for low power wind energy conversion systems.

Using CPE Function to Size Capacitor Storage for Electric Vehicles and Quantifying Battery Degradation during Different Driving Cycles

Abstract: Range anxiety and battery cycle life are two major factors which restrict the development of electric vehicles. Battery degradation can be reduced by adding supercapacitors to create a Hybrid Energy Storage System. This paper proposes a systematic approach to configure the hybrid energy storage system and quantifies the battery degradation for electric vehicles when using supercapacitors. A continuous power-energy function is proposed to establish supercapacitor size based on national household travel survey statistics. By analyzing continuous driving action in standard driving cycles and special driving phases (start up and acceleration), the supercapacitor size is calculated to provide a compromise between the capacitor size and battery degradation. Estimating the battery degradation after 10 years, the battery capacity loss value decreases 17.55% and 21.6%, respectively, under the urban dynamometer driving schedule and the US06. Furthermore, the battery lifespan of the continuous power-energy configured system is prolonged 28.62% and 31.39%, respectively, compared with the battery alone system.

Step-Down DC–DC Converters: An Overview and Outlook

Abstract: Voltage step-down converters have gained attention, with the rapid development in industrial robotics, Internet of things, and embedded system applications. Therefore, a comprehensive analysis has been performed, to identify the topologies and architectures used in step-down converters. Moreover, their operation and performance have been compared. Such an analysis is helpful, in improving performance of the existing systems, besides designing novel converter topologies. Furthermore, the converter-topology-derivation methods have been studied, to identify their applicability for synthesising novel non-isolated DC–DC converters.

Analysis of a Fourth-Order Step-Down Converter

Abstract: This article proposes a nonisolated wider step-down conversion ratio dc–dc converter having minimum phase behavior at nominal operating condition, for point-of-load applications. Compared to existing quadratic/stacked buck converter variants, the proposed topology shows effective switch utilization at low output voltages, lesser ripple content in source current, and reduced voltage/current stress on components. Time-domain analysis is formulated to anticipate the steady-state converter performance and establish design equations for L–C components. The state-space average model is derived and linearized transfer functions are evaluated to subsequently design a fixed-frequency sliding-mode controller. Step-by-step design procedure is presented to fulfil sliding surface existence, reachability, and stability conditions. Equivalent control law devised in this scheme is duly constituted from source side inductor current dynamics and load voltage error information, so it provides simple realization as well as better transient response. The distinctive features of proposed converter are studied analytically and demonstrated through experimental measurements on a laboratory prototype.