Browsing by Author "Balasubramanian, B."

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A Critical Review of MPPT Algorithms for PV Systems
(Institute of Electrical and Electronics Engineers Inc., 2024) P, P.; Anusha, R.; Kumar, V.V.; Balasubramanian, B.
With the growing population, one of the main issues is electricity. Electrical power can be generated from a variety of conventional or non-renewable and non-conventional or renewable energy resources. However, there are negative effects of using non-renewable energy resources on both the environment and the human population. Searching for an alternate energy source is necessary due to the limited availability of these fossil fuels. Among the alternatives that can be used to generate electricity are renewable energy resources that transform energy from the sun, wind, falling water, etc. Solar energy is one among these energy resources that is available in abundant. The fundamental components of photovoltaic (PV) systems are solar cells, which are connected in parallel and series to produce the necessary amount of power. There is only one peak in the PV panel characteristics when all the panels receive the same amount of insolation. However, PV systems commonly experience non-uniform insolation due to shadowing. Their power-voltage (P-V) curve show several peaks under these circumstances, with a single global maximum power point (GMPP) among all. Operating these panels at GMPP during partial shading conditions (PSC) is a challenging task as the insolation keeps changing frequently. This study gives a detailed review of various maximum power point tracking (MPPT) methods that is used during uniform and PSC. This review will help the researchers to explore the possibility of choosing best alternative MPPT techniques to be incorporated for commercial purpose. Â© 2024 IEEE.
A Novel AC Current Sensorless Hysteresis Control for Grid-Tie Inverters
(Institute of Electrical and Electronics Engineers Inc., 2020) Damodaran, R.; Mudlapur, A.; Ramana, V.V.; Balasubramanian, B.; Mishra, S.
Amongst the modulation techniques used for grid-Tie inverters (GTIs), hysteresis current control (HCC) facilitates simple, stable and rugged control with improved dynamic response. However the variable switching frequency of HCC demands high precision AC current sensors (CS) which introduce noise in the power circuit in addition to measurement noise and delay. Therefore, this brief presents a hysteresis current control without AC current sensor based on switching instant computation for a two-level GTI. The proposed control strategy uses the DC link and instantaneous grid voltages to calculate the switching instants. The conventional methods of calculating switching instant of HCC can result in tracking errors. Hence the computations are modified in the proposed algorithm considering the effects of non-linearity in error current and dynamic variations due to supply and load changes. A single-phase GTI is simulated with the proposed control and the results are verified experimentally. The proposed method is observed to considerably reduce the computational time, DC shift and total harmonic distortion compared to the commonly used sensorless current control. © 2004-2012 IEEE.
A novel AC module with high gain Z-Source converter and pseudo DC-link inverter
(Institute of Electrical and Electronics Engineers Inc., 2020) Damodaran, R.; Dastagiri Reddy, B.D.; Balasubramanian, B.
The effects of partial shading in low power PV systems can be considerably reduced by using a single PV module of appropriate rating. Such a system is termed as the AC module in the literature and consists of a PV module along with the required power electronic circuitry, known as module integrated converter (MIC). The AC module integrated with the grid is required to operate at high efficiency and provide an output voltage of the expected magnitude and frequency. In this paper an efficient MIC with pseudo DC-link (pDC-l) for grid integration of AC module is proposed. The proposed MIC is claimed to be high efficient due to the fundamental frequency operation of the inverter. To obtain a pDC-l of required magnitude from single photovoltaic (PV) module, a high gain Z-source buck-boost converter (ZBBC) is used. It is followed by an unfolding circuit which operates at fundamental frequency to convert the pDC-l to sinusoidal output. The fundamental frequency operation reduces the switching losses without affecting the total harmonic distortion (THD). The operation of the ZBBC, when used to obtain a pDC-l output is analysed and a simple closed loop control is developed. The control ensures a pseudo DC-link voltage at the input of the H-bridge that acts as an unfolding circuit. The control also ensures power balance by controlling the current injected to the grid. Simulations of the proposed AC module with ZBBC cascaded with pDC-l inverter have been carried out using MATLAB/Simulink platform and the results are presented to validate the proposed MIC and its closed loop control. Â© 2020 IEEE.
A Novel Algorithm Based on Voltage and Current Perturbation to Track Global Peak Under Partial Shading Conditions
(Institute of Electrical and Electronics Engineers Inc., 2022) P, P.; Vignesh Kumar, V.; Koothu Kesavan, K.K.; Balasubramanian, B.
Under partial shading conditions, photovoltaic (PV) systems exhibit multiple peaks in their power-voltage (P-V) characteristics. It is essential to extract maximum energy from the PV system. The global maximum power point tracking (GMPPT) algorithms presented in the literature, track the global peak using different methods. It is imperative to have minimal convergence time for GMPPT process. This paper proposes a novel algorithm to track the global peak using voltage and current perturbation. The new GMPPT algorithm operates in a current perturbation or voltage perturbation mode, based on the value of a control variable. In either mode, the proposed technique generates reference current or reference voltage, for navigating the operating point to GMPP location. The proposed algorithm is compared with two GMPPT algorithms, namely, modified maximum power trapezium (M-MPT) and high-performance GMPPT algorithms. The simulation studies are performed in MATLAB and is validated using a laboratory prototype, with dSPACE 1202 MicroLabBox controller for implementing GMPPT methods. Simulation and experimental results show that the new technique exhibits superior performance in terms of tracking time. Also, the energy efficiency is improved by 40% while using the proposed GMPPT algorithm for the irradiance profiles considered in this paper compared to the other two techniques. © 1986-2012 IEEE.
A Novel Back to Back Inverter Configuration for Solar Water Pumping and Grid-Tie Application
(Institute of Electrical and Electronics Engineers Inc., 2018) Parmar, J.V.; Reddy, S.K.; Swaminathan, B.; Mudlapur, A.; Balasubramanian, B.
The use of photovoltaic (PV) as an energy source for pumping water is one of the most promising areas of photovoltaic applications. Solar water pumps are eco-friendly substitutes for diesel and grid powered water pumps. They provide better energy efficiency compared to diesel and grid powered pumps and also gives zero-carbon foot print during their use, promoting a healthy and a more sustainable environment. But PV being an unreliable source, prediction of water output is not possible. Further if photovoltaic array generates more power than the load requirement, the excess power is not harvested and when the demand is not met sufficient water is not pumped out. To mitigate this problem this paper presents a back to back voltage source converter (VSC) configuration increasing reliability, robustness and efficiency of the entire system. A new control strategy for back to back VSC for switching between grid-tie and active power factor correction (APFC) mode based on the natural power balance is presented to optimize energy utilisation and ensure maximum water output at all times. Detailed simulation studies are carried out using MATLAB/Simulink to verify the effectiveness of proposed scheme. Â© 2018 IEEE.
A Novel Bi-Directional Converter for Electric Vehicle to Grid Applications
(Institute of Electrical and Electronics Engineers Inc., 2020) Deepak, P.; Damodaran, R.; Balasubramanian, B.; Mudlapur, M.
This paper presents a power converter system that implements bidirectional energy flow between electric vehicle and single phase grid. The proposed topology and control ensures that all major grid requirements such as unity power factor, power quality and total harmonic distortion at grid side are achieved. It also features constant charging current for battery, constant DC link voltage, fast transition in power flow from one direction to another and independent control for power supplied to grid, battery charging current and DC link voltage. The control loop and configuration are such that the system can provide boosting at multiple points and thereby the DC link voltage remains constant irrespective of the power flow direction and turns ratio of the high frequency transformer. Simulated results validate the feasibility of the system and effectiveness of its control. The nonlinearities of the system is taken into account in the simulations. Â© 2020 IEEE.
A Novel Cubic Boost Converter With Continuous Source Current for PV Applications
(Institute of Electrical and Electronics Engineers Inc., 2024) Srinivas, B.; P, P.; Nagendrappa, H.; Balasubramanian, B.
A converter with high voltage gain is generally necessary for interfacing the photovoltaic (PV) systems with grid. However, more semiconductor components are needed to obtain a higher voltage gain, which results in increased losses. This brief proposes a novel non-isolated cubic boost (NNICB) DC-DC converter for high-voltage PV applications with a wide voltage gain at a lower duty ratio. Compared to traditional high-gain DC-DC converter, the NNICB converter counters the drawbacks of increased component count and high voltage stress. The NNICB DC-DC converter has a continuous source current for PV applications with low-voltage stress across the diodes and switches. A detailed steady-state analysis of the NNICB topology is carried out for the ideal and non-ideal models, and their corresponding voltage gain equations are computed. Furthermore, the analysis is performed using MATLAB/Simulink and is validated using a 230 W laboratory prototype. The experimental results show that the efficiency of the proposed NNICB topology is 94.42% with a voltage gain of 10.5 at 45% duty ratio. This proves the superior performance of the proposed novel converter in comparison with the existing topologies. © 2004-2012 IEEE.
A PFC Hysteresis Current Controller for Totem-pole Bridgeless Bi-directional EV charger
(Institute of Electrical and Electronics Engineers Inc., 2022) Adiga, P.S.; Kumar, H.; Iyer, S.R.; Arjun, M.; Dsouza, R.C.; Balasubramanian, B.
The sheer increase in greenhouse gas emissions coupled with depleting fossil fuel reserves has created widespread interest in the design and development of Electric Vehicles; however, the design of reliable charging infrastructures for Electric Vehicles is posing challenges to engineers. Additionally, to enhance the efficiency of these Electric Vehicles, it is desirable for the chargers to have bidirectional power processing capabilities. Therefore, the development of bidirectional Battery chargers is one of the main areas of interest when it comes to EVs. In this regard, this paper presents a Hysteresis Controller for a Bridgeless bidirectional On-Board Battery Charger for Electric Vehicle applications. The AC power is fed from a grid via a totem pole-based AC-DC converter. However, the problem with such a power supply unit is that the design of inner current loop PID compensators is challenging due to the increase in complexity of the mathematical model. Therefore, in this paper, the conventional PID controller of the inner current loop is replaced with a Hysteresis controller. The control strategies have been developed to ensure that the power drawn by the grid is harmonic-free. The simulation study is carried out on a 1.5kW setup using MATLAB/SIMULINK. The proposed system is tested for bi-directional power flow. The simulation results are found to be in total agreement with the studied theory. Â© 2022 IEEE
A Study on High-Frequency Transformer Design with Different Core Configurations for Flyback Converter Topology
(Institute of Electrical and Electronics Engineers Inc., 2023) Vignesh Kumar, V.V.; P, P.; Vangapally, A.; Balasubramanian, B.
The rapid advancements in the switched mode regulator technology necessitate an effective magnetic circuit for the converter topology. The design of magnetics plays a vital role in achieving the essential requirements of switching regulator circuits such as high-power density level, low thermal dissipation and high efficiency. Hence, this paper is focused on the high-frequency practical transformer design for flyback topology that is most widely used in the switched mode power supplies units. A case study is performed by employing different core configuration for high frequency flyback transformer which is the main contribution of this paper. The comparative performance analysis in terms of the dimensions, losses incurred and efficiency is reported for selecting the proper choice of core for the flyback topology. Â© 2023 IEEE.
A Transformerless Photovoltaic Microinverter using High-gain Z-Source Boost Converter for Single-phase Grid connected Applications
(Institute of Electrical and Electronics Engineers Inc., 2020) Prabhu, N.S.; Damodaran, R.; Balasubramanian, B.; Mishra, S.
Microinverters are the latest advancements in the area of photovoltaic (PV) technology due to their compact design. They improve energy efficiency of PV systems due to the reduced effect of non-uniform operating conditions caused primarily by shading. However due to the low output voltage rating of PV modules, high output to input voltage gain ratio is required for microinverters integrated to the utility grid. Several of the existing techniques use transformers or coupled inductors to achieve high gain ratios. These often require precise design and increase the size and cost of the PV system. The Z-source network based high-gain converters can offer superior performance with reduced components, size and cost. However their operation in a microinverter for grid connected applications have not yet been studied. Therefore this paper presents a novel microinverter utilizing a high-gain Z-source boost converter followed by an H-bridge inverter. The principle of operation of the microinverter is detailed and the overall gain ratio is obtained. The operating region in the I-V characteristics of PV module is determined and the control strategies implemented are discussed in detail. Simulations are performed in MATLAB/Simulink platform to validate the performance of the proposed microinverter under possible operating condition. Â© 2020 IEEE.
An Iterative Analytical Solution for Calculating Maximum Power Point in Photovoltaic Systems under Partial Shading Conditions
(Institute of Electrical and Electronics Engineers Inc., 2019) Mudlapur, M.; Ramana, V.V.; Damodaran, R.; Balasubramanian, B.
Detection of maximum power point (MPP) is one of the most sought-after topics in the field of photovoltaic systems. There are many approaches to detecting MPP, amongst these are analytical methods. Analytical methods use mathematical functions to solve the given problem and therefore are one of the dominant strategies. However, their applications to detect MPP have been limited to study only uniform shading conditions. The use of analytical methods to detect MPP for more challenging cases like partial shading conditions is yet to be investigated. In this brief, an analytical solution to identify MPP under partial shading conditions is proposed. Equations describing photovoltaic panels and MPP conditions are derived by applying fundamental circuit laws. The derived equations are non-linear and can be solved using numerical techniques available in most of the simulation packages. The proposed model can theoretically detect the MPP amongst 'N' peaks. The results from the simulation are verified by conducting experimentation with standard algorithms available in the literature. The results from simulation and experimentation are found to agree with each other. © 2004-2012 IEEE.
Design and Analysis of GaN Based Electronic Power Conditioner for Space Applications
(Institute of Electrical and Electronics Engineers Inc., 2025) Indhuja, L.R.; Vignesh Kumar, V.; Desai, N.K.; Balasubramanian, B.; Vinatha Urundady, U.; Rajan Singaravel, M.M.
This paper presents the design and analysis of a forward converter-based multi-output topology utilizing Gallium Nitride (GaN) power devices for Electronic Power Conditioner (EPC) applications in space systems. The proposed topology is tailored for high-frequency operation, leveraging the superior switching characteristics of GaN devices to achieve improved efficiency. To further minimize conduction losses, synchronous rectification is implemented across the point-of-load (POL) converters associated with each output stage. A comprehensive magnetic design approach is explained to support efficient energy transfer in a compact multi-output configuration. The work includes detailed loss analysis based on real GaN device parameters, offering insights into both switching and conduction losses. Simulation results are used to validate the theoretical analysis, providing steady-state waveforms that demonstrate the functional integrity and high efficiency of the proposed converter. This research supports the viability of GaN-based forward converters as a compelling solution for next-generation space power electronics. Â© 2025 IEEE.
Design and Analysis of Single SiC MOSFET Switch Flyback Converter based Control Power Supply for Renewable Applications
(Institute of Electrical and Electronics Engineers Inc., 2020) Jagannath, S.; Agarwal, N.; Balasubramaniasarma, S.; Ma, K.W.; Balasubramanian, B.
This paper presents the use of a 1700 V silicon carbide (SiC) MOSFET in a single switch configuration for a high input voltage control power supply (CPS) design in a flyback topology. Such a CPS is used to power the control and monitoring systems employed in renewable power generation, general purpose drives and uninterrupted power supply (UPS). Renewable applications often see DC bus voltages up to 1000 V. Hence, flyback topology is chosen as it provides an efficient DC voltage step-down for a wide input voltage range with low voltage ripple and desirable regulation. The performance of the flyback converter using a CoolSiCTM MOSFET is observed through appropriate simulations and verified through the hardware prototype. Further, the switching and conduction losses of the MOSFET along with system performance parameters are calculated and the results are presented in this paper. Â© 2020 IEEE.
Design and Laboratory Validation of a Grid-Interfaced Totem-Pole PFC Converter With PR Controller and Isolated Phase Modulated Converter for Solar-Powered Next-Gen EV Charging System
(China Power Supply Society, 2025) Kanimozhi, K.; Kesavan, P.K.; Nagendrappa, N.; Balasubramanian, B.
This paper proposes a stationery reference frame proportional-resonant (PR) controller for current control of grid-tied converters in an EV charger application. Since it is a viable alternative to rotational reference frame PI compensators in AC applications, the PR controller has been adopted for achieving zero steady state error without using any computationally intensive reference frame transformations. In this paper, a method to design the structure of PR controller and its coefficients according to the desired transient behaviour of AC signal amplitude in PFC converter current loop has been proposed. The importance of suggested PR controller design method is that the grid current magnitude is varying constantly based on the available PV power and battery charger levels which necessitates the controller to act in desired transient behaviour. So, by this way the impact of variation in system parameters have been completely overcome by operating the converter controllers appropriately in a solar powered EV charger system. To verify the effectiveness of the proposed controller design, extensive simulations and experimental studies are performed in a 1.5 kW EV charger system under various PV irradiances and charger power levels. The experimental results obtained from the laboratory prototype confirms the simulation findings. © 2025 China Power Supply Society. All rights reserved.
Development of Small Signal Model and Stability Analysis of PV-Grid Integration System for EV Charging Application
(Institute of Electrical and Electronics Engineers Inc., 2024) Kanimozhi, K.; Koothu Kesavan, K.K.; Nagendrappa, N.; Balasubramanian, B.
In this article, grid interactive photovoltaic (PV) system is designed for an electric vehicle (EV) charging application, and the stability of the system is analyzed. The small signal model for the system is derived by averaging and linearizing the state space equations, and the condition for stable operation of PV-integrated charger system is identified from the transfer functions. The proposed charger system implements a coordinated control between the converters to maintain a power balance between the sources and load. System stability is examined using root-locus plots and in addition, the controller is designed to improve the overall stability and reliability of the system. The proposed method provides a general framework for modeling EV charging systems which also details the importance of deriving the model with multiple energy sources. Further, proposed topology has bidirectional capability, which transfers excess PV power to the grid during off-charging hours. The efficacy of the proposed method is verified using the MATLAB Simulink environment for the different scenarios, i.e., variation in the irradiation and disturbances in the grid voltage. The experimental study is conducted on a 1.5-kW laboratory prototype using a low-cost digital signal processing controller (launchpad TMS320F28027F) and the measured results authenticate the simulation findings. © 2020 IEEE.
Effect of Partial Shading on PV Fed Induction Motor Water Pumping Systems
(Institute of Electrical and Electronics Engineers Inc., 2019) Mudlapur, M.; Ramana, V.V.; Damodaran, R.; Balasubramanian, B.; Mishra, S.
Partial shading is one of the certain conditions in photovoltaic (PV) power plants. Often the panels get partially shaded due to soiling, clouds, and trees. The effect of shading is of high concern and importance especially in applications such as water pumps due to agricultural environments in which they are employed in. However, the research focus on PV fed pumps till date has been restricted to only uniform shading conditions. Unlike uniform shading conditions during maximum power tracking, where the panel voltage remains almost constant for an entire range of irradiance, partial shading offer conditions such as highly variable panel voltage and transitions of intermediate DC-DC power converter from continuous conduction mode to discontinuous conduction mode. These effects severely affect the performance of the power converter and, therefore, the power output of the pump. This paper presents a study on the effects caused by partial shading conditions on pumps through simulations and verified by experimentations. The simulation and experimental results are found to be in good agreement with each other. This research thus helps in understanding the detrimental effects caused by partial shading conditions and thus serves as a reference tool for practitioners who wish to study PV fed pumps. © 1986-2012 IEEE.
Efficient global peak tracking of PV system under mismatching conditions using searching technique and bisection method
(Institute of Electrical and Electronics Engineers Inc., 2018) Ramana, V.V.; Mudlapur, A.; Damodaran, R.; Balasubramanian, B.; Mishra, S.
Rapidly increasing energy demand is leading to increase in installation of photovoltaic (PV) plants across the globe. The PV modules are subjected to various conditions like shading, soiling and degradation because of which the performance of PV panels deteriorates. This will affect the characteristics of PV module which may lead to several stairs in I-V curves and several peaks in P-V curve. In this paper the various causes of occurrences of mismatching conditions are analyzed. An efficient two stage algorithm that tracks global maximum power point (GMPP) accurately under such mismatching conditions is proposed in the paper. In the first stage, a simple searching technique and bisection method are used to bring the operating point to the proximity of global maximum. In the second stage, hill climbing method maintains the operating point at global peak. MATLAB Simulations and experimental verifications are performed for validating the proposed approach. Â© 2018 IEEE.
EGA-FMC: Enhanced genetic algorithm-based fuzzy k-modes clustering for categorical data
(2018) Narasimhan, M.; Balasubramanian, B.; Kumar, S.D.; Patil, N.
Categorical data clustering is the unsupervised technique of grouping similar objects which have categorical attributes. We propose a genetic algorithm-based fuzzy k-modes categorical data clustering algorithm using multi-objective rank-based selection with enhanced elitism operation. Compactness of the clusters and inter-cluster separation were chosen as objectives to be optimised. During elitism, in every iteration, the best parent chromosomes were identified. The entire population was passed through the selection, crossover and mutation steps. The worst children were then replaced by the best parents. Our method was evaluated on three real-world datasets and resulted in clusters of better quality as compared to current methods with a significant reduction in computation time. Additionally, statistical significance tests were conducted to show the superiority of our approach over other clustering solutions. Copyright 2018 Inderscience Enterprises Ltd.
EGA-FMC: Enhanced genetic algorithm-based fuzzy k-modes clustering for categorical data
(Inderscience Enterprises Ltd., 2018) Narasimhan, M.; Balasubramanian, B.; Kumar, S.D.; Patil, N.
Categorical data clustering is the unsupervised technique of grouping similar objects which have categorical attributes. We propose a genetic algorithm-based fuzzy k-modes categorical data clustering algorithm using multi-objective rank-based selection with enhanced elitism operation. Compactness of the clusters and inter-cluster separation were chosen as objectives to be optimised. During elitism, in every iteration, the best parent chromosomes were identified. The entire population was passed through the selection, crossover and mutation steps. The worst children were then replaced by the best parents. Our method was evaluated on three real-world datasets and resulted in clusters of better quality as compared to current methods with a significant reduction in computation time. Additionally, statistical significance tests were conducted to show the superiority of our approach over other clustering solutions. © © 2018 Inderscience Enterprises Ltd.
Experimental investigation of the effectiveness of the LC filter in PV fed induction motor water pumping systems with different type of inductors
(Institute of Electrical and Electronics Engineers Inc., 2018) Mudlapur, A.; Subrahmanya Adiga, P.; Anusha, R.; Balasubramanian, B.
This paper presents the experimental study of the effectiveness of the LC filter in PV fed water pumping systems. This study is very important in water pumping applications where prolonged running conditions is a major concern. LC filters are connected at the terminals of the inverter to avoid transient over voltages across the induction machine. The conventional LC filter with lumped gap inductor is studied initially. The temperature of the filter inductor is monitored to study its behaviour. It is inferred that the inductor temperature increases drastically due to the high winding losses and therefore may lead to system failure when run for longer duration. The inductor is replaced with uniformly distributed(powdered) core and low cost discretely distributed gap core so as to minimize the losses. Comparative study between the conventional and proposed inductors is carried out. It is inferred that discretely distributed gap inductors are a better choice over powdered core inductors. The experimentation is carried out on a 3-HP induction motor and results with lumped gap and discretely distributed gap inductors are presented along with their thermal profiles. Results show that, the discrete distributed gap inductor is the cost effective solution for the LC filter failures in water pumping applications. Â© 2018 IEEE.