Subhransu Padhee

Investigation on Transient Response of Fuel Cell Power Conditioning Unit during Rapid Load Changes

Fuel cell is one of the renewable energy sources used extensively in stand-alone as well as grid tied applications. Fuel cell provides a low voltage and high current DC output which has to be properly conditioned according to the demand of load. Therefore, a power conditioning unit (PCU) is essential for processing the unregulated DC voltage. The PCU posses different dynamics from the fuel cell, so proper modeling of fuel cell as well as PCU is essential. Tight voltage regulation of the power converters used in PCU is also necessary, so that regulated power can be provided to sophisticated load. The transient state performance and recovery time during load changes has to be very small. This paper focusses on the application of synchronous buck converter which provides low voltage output for different appliance of electric vehicle. Synchronous buck converter is used because of its low losses. A digital compensator is used to control the voltage during sudden changes in load profile. Simulation studies are performed to study the transient state performance of the converter.

Design of an educational laboratory for measurement and data acquisition system

This paper describes the design details of a measurement and data acquisition laboratory. The main purpose of this laboratory is to experimentally validate the theoretical concept of sensors, signal conditioning circuits and data acquisition devices. The developed laboratory course emphasizes on theoretical concept of different temperature sensors, signal conditioning circuit of the respective sensors, hardware of data acquisition system and related software interfacing of the hardware using LabVIEW.

Comparative analysis of DC-DC converter topologies for fuel cell based application

Power electronic converters play an important role in integrating renewable energy sources in to the electrical grid. A power conditioning unit (PCU) which comprises of different power electronic converters is essential to process the power of renewable energy sources and make it useable for stand-alone or grid-tied application. DC-DC converters are used in the primary stage of PCU to step up the voltage of renewable energy source to a desired level and also to improve the conversion efficiency. In this paper, a comprehensive analysis is carried out to provide details about different non-isolated, isolated and soft switched converters used in PCU. The performance of these converters are analyzed according to their conversion efficiency and number of components.

Closed-loop parametric identification of DC-DC converter

This study provides a step-by-step analysis of closed-loop parametric system identification for DC-DC buck converter. In closed-loop parametric identification, input–output experimental data are used to estimate the transfer function coefficients of DC-DC buck converter. For system identification purpose, a high-frequency perturbation signal is injected in to the closed-loop system which acts as an input signal for identification experiment. Different input–output models such as Auto-Regressive eXogenous, Auto-Regressive Moving Average with eXogenous, output error, and Box–Jenkins are used to model the converter structure and prediction error method is used to estimate the parameters. Model validation schemes are used to validate the estimated model. Simulation and experimental analysis have been provided to validate the results obtained.

Overview of High-Step-Up DC–DC Converters for Renewable Energy Sources

ABSTRACT To utilize the power generated from renewable energy sources and use it in stand-alone or grid integrated application, power conditioning unit (PCU) is required. The main consideration in designing a PCU is lower cost, higher reliability, higher efficiency, and robust operation. One of the major components of PCU is high-step-up and high-efficient DC–DC converter. This paper provides a comprehensive topological review of different high-step-up DC–DC converter topologies. A wide variety of DC–DC conversion topologies (both transformerless and isolated) with wide voltage conversion ratio have been reviewed. To improve the converter efficiency, various soft-switching techniques are implemented. This paper intends to serve as one of the convenient reference for future researchers.

Modeling of DC–DC Converter Using Exact Feedback Linearization Method: A Discussion

ABSTRACT DC–DC converter finds widespread use in variety of applications. DC–DC converter inherently possess nonlinear dynamics, therefore different linearization schemes are used to get a linearized model of the converter. The classical state-space averaging method is one of the most widely used linearizing method for DC–DC converter. But the said linearization method has some inherent limitation which limits the accuracy of the developed linearized model. This paper provides a discussion of mathematical modeling of DC–DC converter operating in continuous conduction mode as well as in discontinuous conduction mode using exact feedback linearization (EFL) technique which is based on Lie algebra. A linearized model of the converter is obtained using EFL and the effect of change in duty cycle and change in circuit parameters on the frequency response has been studied. The frequency response of the EFL model and nonlinear model is matching within the range of duty cycle and load resistance considered in this paper.

Design of measurement and data acquisition laboratory for instrumentation engineering course

This paper presents design, development, implementation and assessment details of a low-cost educational laboratory setup which can be used to teach the basic and advanced principles of measurement as-well-as data acquisition system in instrumentation engineering course. With the help of this laboratory the students can understand the operational principles of different sensors, signal conditioning circuit, computing device and communication media. The laboratory course uses open-source software, open-source hardware tools integrated with information and communication technologies.

Design of stand alone PV system for DC-micro grid

This paper provides modeling of photovoltaic (PV) panel, designing of maximum power point tracking (MPPT) control algorithm for a standalone PV based distributed generation (DG) system. A detailed mathematical model of PV panel is provided. One of the most classical MPPT (Perturb and Observe MPPT) is used to track the maximum power point of the system. SunPower PV array are considered and simulation results showcase the module characteristics and array characteristics. A detailed design technique is provided for MPPT technique and simulation are carried out with varying solar irradiance.

Mathematical modelling and voltage control of fuel cell

Fuel cell is one of the efficient renewable energy storage devices available. This paper provides a detailed electrical modeling of fuel cell system and an overview of required control schemes for fuel cell. Fuel cell provides low DC output which is further processed using power conditioning unit (PCU) comprising of power electronic converter. This paper provides a detailed mathematical model and control of classical DC-DC boost converter connected with a 6 kW proton exchange membrane fuel cell (PEMFC).

Modelling switched mode DC-DC converter using system identification techniques: A review

Multi converter based distributed power system (DPS) comprises of several interconnected switched mode power converters. The large scale implementation of DPS in variety of applications has provided new research directions in modeling and control of switched mode power converter. With evolution of DPS, black box, grey box modeling and identification of converter dynamics holds a significant research interest. A large number of papers study the identification aspect as well as real time implementation of identification techniques in switched mode power converter. Therefore, a proper review of available identification methods is the need of the day. In this paper, comprehensive reviews of parametric and non-parametric identification techniques of switched mode power converter have been discussed. This paper is intended to serve as a reference towards identification aspect of switched mode power converter.