Browsing by Author "Gaonkar, D.N."

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A comprehensive review on control techniques for power management of isolated DC microgrid system operation
(Institute of Electrical and Electronics Engineers Inc., 2021) Bhargavi, K.M.; Sabhahit, N.S.; Gaonkar, D.N.; Shrivastava, A.; Jadoun, V.K.
The present research investigations in power management fraternity are focused towards the realization of smart microgrid (MG) technologies. Due to intrinsic advantages of Direct Current (DC) system in terms of compatibility with power generation sources, modern loads and storage devices, DC MG has becoming popular over Alternate Current (AC) system. A secondary voltage and current control schemes of DC MG system are mainly based on the distributed consensus control of Multi-agent system (MAS) to balance generation and the demand. The basic concern of the cooperative control of MAS is consensus, which is to design a suitable control law such that the output of all agents can achieve synchronization. The distributed consensus algorithm requires much less computational power and information exchange in between the neighbor's agent. Meanwhile the other controllers such as model predictive control (MPC) requires accurate dynamic models with high computational cost and it suffers from lack of flexibility. The hierarchical consensus control technique is classified into three levels according to their features, namely primary, secondary, and tertiary. MAS is a popular distributed platform to efficiently manage the secondary control level for synchronization and communication among the power converters in autonomous MGs. In this article, various primary control techniques for local voltage control, voltage restoration in the secondary control level and tertiary control for energy management techniques are discussed. With this, the key emphasis to reduce the voltage deviation and disturbances in a heterogeneous DC MG network solutions are discussed. Furthermore, to analyze the system response and the charging and discharging characteristics of the battery unit, the developed second order heterogeneous consensus controller is compared with the traditional homogeneous consensus control and droop control methods. Finally a detailed discussion on simulation case study using heterogeneous consensus control method over the traditional methods are provided using MATLAB/Simulink platform. © 2021 Institute of Electrical and Electronics Engineers Inc.. All rights reserved.
A control strategy for power management in a PV-battery hybrid system with MPPT
(Institute of Electrical and Electronics Engineers Inc., 2017) Sabhahit, J.N.; Gaonkar, D.N.; Adarsh, S.; Sunil, S.
The paper presents a control strategy which manages the power flow between a Photovoltaic (PV) module, battery and the load. Since PV system provides an unregulated voltage output, it is regulated to a desired voltage level and then given to the charge controller, which distributes the power between battery and load. To extract acme power from PV system, a Maximum Power Point Tracking (MPPT) scheme is employed. The excess energy left, after meeting the load demand, is stored in the battery. The stored energy is utilized to meet the future load demands, when there is a power deficit from the PV system. Hence power requirement of the load is managed. Also a comparison between the three commonly used MPPT techniques: Perturb & Observe (P&O) algorithm, Incremental Conductance (IC) algorithm and Fractional Open Circuit Voltage (FOCV) algorithms is done and the most suitable technique is employed for the hybrid system. When the battery is fully charged, the excess power is absorbed by the dump load, which is also managed by the charge controller. The entire hybrid system is simulated and verified in the MATLAB/Simulink platform. Â© 2016 IEEE.
A Fast and Robust PLL Design with a Combination of Frequency-Adaptive Alpha-Beta-CDSC and SOGI
(Institute of Electrical and Electronics Engineers Inc., 2025) Mondal, S.; Gayen, P.K.; Gaonkar, D.N.
Recent research has focused on the enhancement of the prefiltering capability of phase-locked loops (PLL). The cascaded delayed signal cancellation (CDSC) PLL removes the low-order selective harmonic frequencies near the fundamental frequency. Here, a frequency-adaptive time delay unit is used to cope with frequency and phase variations of voltage. The high-frequency signal arising due to the frequency-adaptive loop cannot be mitigated. In effect, the transient response of adaptive CDSC-PLL shows a significant irregular pattern. Therefore, this article suggests the use of a second-order generalized integrator (SOGI) after the adaptive CDSC unit to improve the transient profile of frequency response. In the design, the high gain (K = 5.4) of SOGI is chosen to quickly settle the response of PLL at the expense of its ignorance of lower-order harmonics near the fundamental frequency. However, the lower-order harmonics are selectively eliminated by the CDSC unit. So, both prefilters complement each other's filtering capabilities. Additionally, the suggested prefilter provides improved noise immunity and eliminates DC offset via the SOGI unit. The linearized model and tuning procedure for the different control parameters of the proposed PLL are described. The real-time hardware-in-loop tests are executed to justify the optimum performance of the proposed PLL. © 2024 IEEE.
A Hybrid Islanding Detection Method Based on Lissajous Pattern Having Robust Performance Under Various Power Quality Scenarios
(Institute of Electrical and Electronics Engineers Inc., 2023) Mondal, S.; Gayen, P.K.; Gaonkar, D.N.
A fast, accurate, robust, and two-staged islanding detection technique (IDT) is proposed. It is the hybridization of second-order general integrator-frequency locked loop (SOGI-FLL), Lissajous pattern (LP), and active power absorption-cum-reactive power injection via dc-bus connected battery unit-based inverter. The LP is used to identify islanding condition on the basis of frequency variation of fundamental voltage. Here, the measured ac voltage signal is preprocessed by SOGI-FLL to obtain fundamental bus voltage under various power quality scenarios. This assures robust islanding detection by removing uncertainty, and thus, reliability is improved. The uncertainty effects due to the partial shading condition of the PV module (source-side disturbance) and weak grid-connected condition are avoided by dc-bus connected battery storage unit. Thus, it removes above-said limitations of the existing scheme. The LP-based detection within the nondetection zone is expedited due to active and reactive powers variation via controlling of the inverter and charging operation of the dc-bus connected battery unit. During the reactive power injection by solar inverter, active power is absorbed by dc-bus connected battery unit. In effect, an active power output of the inverter is reduced. Here, the reactive power injection at the reduced active power output condition of the inverter accelerates frequency variation allowing rapid islanding detection. The real-time experiments are carried out using Typhoon-HIL tools to compare the proposed method with other works reported in the literature. Improved performances under diversified scenarios are found in the proposed case. © 2007-2012 IEEE.
A new control method to mitigate power fluctuations for grid integrated PV/wind hybrid power system using ultracapacitors
(Walter de Gruyter GmbH info@degruyter.com, 2016) Sabhahit, N.S.; Gaonkar, D.N.
The output power obtained from solar-wind hybrid system fluctuates with changes in weather conditions. These power fluctuations cause adverse effects on the voltage, frequency and transient stability of the utility grid. In this paper, a control method is presented for power smoothing of grid integrated PV/wind hybrid system using ultracapacitors in a DC coupled structure. The power fluctuations of hybrid system are mitigated and smoothed power is supplied to the utility grid. In this work both photovoltaic (PV) panels and the wind generator are controlled to operate at their maximum power point. The grid side inverter control strategy presented in this paper maintains DC link voltage constant while injecting power to the grid at unity power factor considering different operating conditions. Actual solar irradiation and wind speed data are used in this study to evaluate the performance of the developed system using MATLAB/Simulink software. The simulation results show that output power fluctuations of solar-wind hybrid system can be significantly mitigated using the ultracapacitor based storage system. © by De Gruyter 2016.
A New Islanding Detection Method Using Transfer Learning Technique
(IEEE Computer Society help@computer.org, 2018) Manikonda, S.K.G.; Gaonkar, D.N.
The increasing need for energy in the recent times is unprecedented, which is driving the penetration of renewable sources in distribution system in a big way. The increasing number of renewable sources in a system has made the operation, control and protection of the system very complex. One of the key issues in seamless interconnection of renewable energy sources to a system is islanding. This paper proposes a new method to detect islanding in an efficient way by employing transfer learning based technique for image classification. The results show that the proposed method can successfully classify islanding events with a good accuracy. Â© 2018 IEEE.
A Novel Approach for Steady State Calculations of VSC-HVDC Connected PMSG Based Offshore Wind Farms Integrated into Multi-Machine Systems
(Taylor and Francis Ltd., 2023) Rashmi, n.; Gaonkar, D.N.
Offshore wind farms equipped with Direct Drive Permanent Magnet Synchronous Generators (DD-PMSG) are drawing increased attention due to their advantage over other variable speed technologies. VSC-HVDC links are considered the most suitable option for transferring power to the onshore system. The integration of VSC-HVDC connected DD-PMSG based offshore wind farms into multi-machine systems is explored in this paper. A novel approach for power flow and initial condition calculations is proposed to facilitate dynamic analysis of the system. For three cases of the most commonly specified quantities of the wind farm, efficient methods have been described. The cases comprise combinations of data like the total output of the wind farm, the number of wind turbines, the wind speed, or the output of individual wind turbine, which are frequently given in literature. This approach enables the user to build the dynamic model of the system in any basic graphical dynamic modeler and numerical computational software without requiring power system toolboxes or electromagnetic transient packages. The proposed methods are highly effective for studies focusing primarily on the dynamic aspects and controls of the system. Case studies and simulations are conducted to verify the proposed technique. © 2023 Taylor & Francis Group, LLC.
A Novel Islanding Detection Method Based on Transfer Learning Technique Using VGG16 Network
(Institute of Electrical and Electronics Engineers Inc., 2019) Manikonda, S.K.G.; Gaonkar, D.N.
The escalating need for energy in the recent times is unprecedented, which is driving the penetration of renewable energy sources in distribution system in a big way. The growing number of renewable sources in a system has made the control, operation and protection of the system very complex. Among others, one of the key issues in seamless interconnection of renewable energy sources to a system is islanding. This paper proposes a new and efficient islanding detection method that employs transfer learning based technique. The results show that the proposed method can successfully classify islanding events with a good accuracy. Â© 2019 IEEE.
A Novel Islanding Detection Technique Based on Piezoelectric Sensors for Grid-Integrated DG Systems
(Taylor and Francis Ltd., 2023) Kulkarni, S.V.; Hegde, V.; Gaonkar, D.N.
This paper presents the novel islanding detection technique that depends on the piezoelectric sensors for distributed generation sources (DGs) in the grid-integrated operation mode. The islanding detection method employs a piezoelectric sensor for the detection of the frequency variations during grid disruptions. The designed diaphragm-based sensor has a natural frequency as that of the fundamental frequency of the system frequency signal. Any further deviations from the natural frequency due to the disturbances will be sensed by the sensor and a control signal is being sent to the associated circuit breaker for suitable action. The sensor structure is modeled using the finite element method and implemented in the Phase-Locked Loop (PLL) of the grid-integrated DGs. The proposed circular diaphragm-based sensor structure will have the bandwidth in the range of natural frequency with the tolerance rate of ±1% and uses the input signal received from the PLL controller outer loop. The proposed islanding detection technique’s performance and reliability for grid-integrated DG are validated using the real-time hardware in the loop test-bed platform. The HIL virtual simulated responses show that the method can be proposed effectively for islanding detection in the event of frequency variations in the grid-integrated DG systems. © 2023 IETE.
A Novel Method for Energy Trading in Networked Microgrids Using Matching Theory
(Institute of Electrical and Electronics Engineers Inc., 2022) Biji Varghese, K.V.; Gaonkar, D.N.
This Paper proposes matching based energy trading mechanism among microgrids to trade energy flexibly in a networked distribution system. We consider an interconnected microgrid network system where some microgrids have an excess of power after their local utilization to sell, termed as sellers, whereas some other microgrids request additional power to meet demand. Energy trading is formulated as a matching problem where the sellers find suitable matches based on the sellers' preference matrix. The preference matrix is generated using the price proposed by the buyer microgrids. The buyer microgrids calculate the trading prices by considering the operational cost, virtual cost and generation cost, and the seller microgrids accept the proposal only if it's greater than the minimum trading price calculated by the seller. We also analyze that due to the power transfer between the microgrids instead of the utility grid., there is a reduction in power loss across the networked system during the power transfer We study the proposed theory on the distribution network containing different numbers of microgrids, and the numerical results are compared with the conventional energy trading methods to verify the effectiveness of the proposed approach. Â© 2022 IEEE.
A novel reduced-cross-tied configuration for extracting maximum power output from a symmetrical PV array under partial shading conditions
(Springer Science and Business Media Deutschland GmbH, 2024) Ramesh, D.; Karthikeyan, A.; Gaonkar, D.N.
The primary reason for the decrease in power output from the PV array is partial shading. During partial shading conditions (PSCs) PV modules experience a mismatch in current and voltage generated. Also, the power voltage (P–V) characteristics of the PV array possess multiple peaks under PSCs. To mitigate the effects caused by PSCs, the configuration of the PV array is the finest solution. This paper proposes a novel Reduced Cross Tied (RCT) configuration to enhance maximum power output from a symmetrical PV array under PSCs. The RCT configuration has fewer cross-ties compared to the TCT configuration and is applicable to a square array of any size. The proposed RCT configuration along with conventional configurations such as Total Cross Tied (TCT), Series–Parallel, Bridge-Link, and Honey-Comb are validated in simulation and hardware for 7×7 and 8×8 symmetrical PV arrays under Short and Narrow (SN), Short and Wide (SW), Long and Narrow (LN) and Long and Wide (LW) shading patterns. A comparative analysis is done between the proposed configuration and conventional configurations in terms of mismatch loss (ML), fill factor, efficiency (η), Wiring Loss, and Global Maximum PowerPoint (GMPP). The proposed RCT configuration is able to achieve GMPP equal to the TCT configuration under the LN shading pattern and on par with the TCT configuration under SN, SW, and LW shading patterns. RCT-configured PV array possesses a minimum reduction of 25% in wiring loss for any array size. RCT configuration applies to a square array of any size.The results replicate the efficacy of the proposed RCT configuration compared to existing configurations. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023.
A Novel Simplified Modeling Approach for VSC-HVDC Links in Performance Analysis of Multi-Machine Systems
(Springer Nature, 2024) Rashmi, n.; Gaonkar, D.N.
In this paper, a simplified model of voltage source converter-based high-voltage direct current (VSC-HVDC) link is proposed that is effective in the analysis of multi-machine systems, even when crucial applications of the link are involved. The model is derived by eliminating the DC dynamics, including the converter-related impedances as a part of the AC system transmission network and obtaining the converter currents in a straightforward manner. Case studies are conducted on 4-machine, 10-bus and 16-machine, 68-bus systems to prove the accuracy of the model. The study clearly indicates the model’s ability to reproduce the influence of VSC controllers, impact of variable power levels and effects of multiple HVDC links in a system. It is further verified for significant VSC-HVDC applications. The model is effective at handling frequency support of asynchronous systems and can be applied to VSC-HVDC connected offshore wind farms feeding multi-machine systems. It is demonstrated that the proposed model can be efficiently used for analysis of large AC systems embedded with VSC-HVDC links with lesser modeling complexity and computation time. © King Fahd University of Petroleum & Minerals 2023.
An accurate modeling of different types of photovoltaic modules using experimental data
(International Journal of Renewable Energy Research, 2016) Ramana, V.V.; Jena, D.; Gaonkar, D.N.
In this paper an approach to model different types of PV modules using single diode model is presented. The proposed method utilizes the characteristics of diode ideality factor, shunt resistance and series resistance independently for developing accurate solar PV model. Apart from this, the proposed model utilizes experimental values obtained from the solar array simulator for implementing the proposed approach. The procedure mainly focuses on developing an accurate method for thin film solar modules using a simplified approach. The model is implemented in MATLAB and is validated with existing model and experimental values obtained from solar array simulator.
An adaptive reactive power perturbation based hybrid islanding detection method for distributed generation systems
(Acta Press journals@actapress.com, 2016) Krishnan, G.; Gaonkar, D.N.
The intentional islanding operation of distributed generation (DG) systems can bring many benefits to the DG owner, distribution network operators and customers. One of the requirements for intentional islanding operation is the successful detection of the grid events which can lead to islanding of the DG system. This paper presents the hybrid islanding detection method based on adaptive reactive power variation with a passive algorithm that relies on the transient response characteristics for facilitating islanding detection. The proposed method presented in this paper can overcome the problems in the reactive power variation based methods. Extensive studies are conducted for differentiating the transient characteristic features for islanded and non-islanded systems. In this study the adaptive reactive power sequence is modified to enhance the performance under sudden load changes. The proposed method proved to detect all probable islanding situations with minimum run-on time. The performance of the method is evaluated using simulation results obtained from MATLAB/SIMPOWERSYSTEMS software considering wind power based DG system.
An integrated Control Approach and Power Management of Stand-alone Hybrid Wind/PV/Battery Power Generation System with Maximum Power Extraction Capability
(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2015) Sabhahit, N.S.; Gaonkar, D.N.
The production of electricity from renewable energy sources like wind and photovoltaic energy has increased in recent years, due to environmental problems and the shortage of traditional energy sources. In this article we present a detailed mathematical model and a control scheme for hybrid wind and PV based DG system with battery and maximum power extraction capability for isolated mode of operation. The wind power generation system uses wind turbine (WT), a permanent magnet synchronous generator (PMSG), a three-phase diode rectifier bridge, DC/DC boost converter with maximum power point tracking (MPPT) controller. The PV generation system uses PV array, a boost converter with maximum power point tracking controller. Both sources and battery are connected to common dc bus with a dc link capacitor and supply power to load through PWM voltage source inverter. The overall control system consists of MPPT controller for both Wind and PV power system, a bi-directional DC-DC converter controller for battery energy storage management and load side inverter controller for voltage and frequency regulation. Control strategies for individual system components of the proposed system are designed with a view to achieve an acceptable level of voltage and frequency regulation while extracting the maximum power from wind and PV system. The performance of the developed hybrid system is investigated in terms of voltage and frequency regulation capability under changing wind, solar irradiation and variable load conditions.
An investigation of PLL synchronization techniques for distributed generation sources in the grid-connected mode of operation
(Elsevier Ltd, 2023) Kulkarni, S.V.; Gaonkar, D.N.
In recent years, the proliferation of grid-connected microgrid systems has witnessed a remarkable surge, driven by the need to enhance the availability and reliability of renewable energy sources during peak demand periods. By reducing reliance on fossil fuels, these systems offer promising avenues for sustainable energy integration. To ensure seamless synchronization of renewable energy sources with the grid, Phase-Locked Loop (PLL) controllers have emerged as a key solution. However, the information available about these PLLs is limited. In this paper, the analysis, design, and comparison of PLLs, along with the exploration of a recently developed PLL synchronization method. Specifically, we evaluate the performance of prominent PLL techniques, including PSRF-PLL, SOGI-PLL, DSOGI-PLL, E-PLL, and IPT-PLL, under diverse test scenarios such as voltage sag, swell, unbalance, and harmonics. To assess their effectiveness, hardware-in-loop virtual and real-time test-beds are employed, enabling rigorous examination of the PLL techniques for grid synchronization. The reported results demonstrate the phase tracking capability when operating in grid-connected mode. Finally, conclusions are drawn from studies conducted in the electrical grid network's healthy and unhealthy environments. © 2023 Elsevier B.V.
Battery Storage-Based Novel Hybrid Islanding Detection Technique Using Lissajous Pattern Estimation
(Institute of Electrical and Electronics Engineers Inc., 2022) Mondal, S.; Gayen, P.K.; Gaonkar, D.N.
The reliability, uncertainty, and sensitivity of local islanding detection method for distributed generation (DG) system under diversified real-time scenarios and nonlinear loading conditions are not greatly explored. In this article, a new type hybrid islanding detection technique (IDT) is suggested, which reduces uncertainty and simultaneously improves reliability and sensitivity under different situations. In the technique, one detection parameter is defined, which is calculated from estimation of major and minor axes of Lissajous pattern (LP). Here, the evaluation of the parameter is done in two stages to avoid erroneous detection. In the first stage, the initiation of voltage transient is detected by LP. In the second stage, the active control via battery energy storage system (BESS) distinguishes nuisance tripping case from the islanding state. The extra active power injection/absorption via BESS also helps to identify islanding state at very near to zero power condition, i.e., sensitivity is enhanced. The detection time is found within 160 ms for different test cases, which is well below that of the acceptable upper value (2 s) specified in standard. The uncertainties in detection and threshold setting due to variations of harmonics and other operating conditions are removed in the proposed case, which is a distinct advantage. The Typhoon-HIL tool is used to carry out various case studies in real-time. Here, superior performances of proposed approach are observed in comparison with other state of the arts reported in the literature. © 1963-2012 IEEE.
Battery-ultracapacitor storage devices to mitigate power fluctuations for grid connected PV system
(2016) Jayalakshmi, N.S.; Gaonkar, D.N.; Kumar, J.V.; Karthik, R.P.
This paper presents a control strategy based on energy storage systems to minimize the output power fluctuations for a PV system. Solar energy is naturally intermittent with stochastic fluctuations, by virtue of which, stability and power quality of grid operation are affected. This makes grid integration of PV system cumbersome. The aim of this study is to develop a control strategy to deliver smoothened power to the grid, using battery and ultracapacitors for a grid connected hybrid system. The fluctuating power is absorbed by a battery and ultracapacitors during erratic solar power variation, thus being able to mitigate the power fluctuations to the grid. Bidirectional converters are used in tandem with a battery and ultracapacitors to ensure active energy flow between the grid and the storage systems. The inverter control strategy is implemented such that it will maintain a constant DC link voltage. The PV power system is controlled to extract maximum power. Dynamic modeling and simulation study are accomplished using MATLAB/Simulink. � 2015 IEEE.
Battery-ultracapacitor storage devices to mitigate power fluctuations for grid connected PV system
(Institute of Electrical and Electronics Engineers Inc., 2016) Sabhahit, N.S.; Gaonkar, D.N.; Jhunjhunwala, J.V.; Karthik, R.P.
This paper presents a control strategy based on energy storage systems to minimize the output power fluctuations for a PV system. Solar energy is naturally intermittent with stochastic fluctuations, by virtue of which, stability and power quality of grid operation are affected. This makes grid integration of PV system cumbersome. The aim of this study is to develop a control strategy to deliver smoothened power to the grid, using battery and ultracapacitors for a grid connected hybrid system. The fluctuating power is absorbed by a battery and ultracapacitors during erratic solar power variation, thus being able to mitigate the power fluctuations to the grid. Bidirectional converters are used in tandem with a battery and ultracapacitors to ensure active energy flow between the grid and the storage systems. The inverter control strategy is implemented such that it will maintain a constant DC link voltage. The PV power system is controlled to extract maximum power. Dynamic modeling and simulation study are accomplished using MATLAB/Simulink. Â© 2015 IEEE.
Combined model of fuel cell and microturbine based distributed generation system
(2011) Nayak, S.K.; Gaonkar, D.N.; Kumar, A.S.
Distributed Generation (DG) play an active role in the distribution network due to its minimum loss, maximum efficiency and environmental impact. Moreover DG can supply base load power which improves the system stability, reliability and power quality. Among the different combined DG systems like solar with wind, tidal with geothermal and others, fuel cell with microturbine is the most economical due to fuel flexibility and inner relation between each other. The hybrid system can utilize exhaust fuel and heat from fuel cell to increase the system efficiency. This paper investigates combined model solid oxide fuel cell/microturbine generator (SOFC/MTG) hybrid system, in which the anode exhaust of SOFC contains reminder of fuel. The exhaust hot gas and waste fuel are mixed with fresh fuel and compressed air is burned inside the burner. The pressurized hot gas from the combustor is expanded through turbine driving the Permanent Magnet Synchronous Machine (PMSM). The governing schemes of combined SOFC/MTG (Fuel & air flow) are controlled by the DC link voltage and current. The generated power of MTG is converted to AC/DC/AC to combine with fuel cell and frequency conversion. The hybrid model of SOFC/MTG with power converter is developed in MATLAB/Simulink library and simulation result shows transient response of hybrid SOFC/MTG DG system. � 2011 IEEE.