Venkata Reddy Kota

Bio: Venkata Reddy Kota is an academic researcher from Jawaharlal Nehru Technological University, Kakinada. The author has contributed to research in topics: Maximum power point tracking & Control theory. The author has an hindex of 9, co-authored 46 publications receiving 345 citations. Previous affiliations of Venkata Reddy Kota include University College of Engineering & Jawaharlal Nehru Technological University, Hyderabad.

A novel linear tangents based P&O scheme for MPPT of a PV system

Abstract: This paper first presents an overview on traditional Maximum Power Point Tracking (MPPT) algorithms. Traditional algorithm can be easily implemented using analog or digital devices. As traditional algorithms suffer from low efficiency, oscillations in steady state power and poor dynamic performance, a novel MPPT scheme using Linear Tangents based Perturb & Observe (LTP&O) is proposed in this paper. In order to validate their performance, proposed scheme and other traditional algorithms are simulated using Matlab/Simulink. Simulated results provide evidence that the proposed method has better accuracy, increased efficiency, low oscillation, improved steady state and dynamic performance compared to traditional methods.

A novel global MPP tracking scheme based on shading pattern identification using artificial neural networks for photovoltaic power generation during partial shaded condition

Abstract: Efficiency of the photovoltaic (PV) power generating system is affected during partial shaded condition (PSC). The power-voltage characteristic of PV system exhibits multiple peaks during PSC. It is the task of maximum power point tracking (MPPT) controller to track global maximum power point (GMPP). Conventional MPPT schemes stop at first peak and fail to accomplish GMPP during PSC. Metaheuristic algorithms developed to track GMPP are complex, costly and require much time to track GMPP. Hence, this study put forwards a novel GMPPT scheme for effective tracking based on shading pattern identification using artificial neural network (ANN). In this scheme, ANN is used to estimate the shading pattern on PV panels and a two-dimensional lookup table supplies the MPP voltage corresponding to the shading pattern. By maintaining this voltage across PV panel, maximum power is extracted. The proposed scheme is compared with the existing artificial bee colony and particle swarm optimisation algorithms under different shading configurations to verify their performance under PSC. It is observed that the proposed scheme extracts maximum power effectively under various partial shading conditions. The proposed scheme is implemented in field-programmable gate array (FPGA) controller and the experimental results prove effectiveness of the proposed scheme.

Direct instantaneous torque control of Brushless DC motor using firefly Algorithm based fractional order PID controller

Abstract: In this paper, a Firefly Algorithm (FA) based Fractional Order PID (FOPID) Controller is proposed for Brushless DC (BLDC) motor to achieve an effective control of torque and speed. In a conventional control of BLDC motors, the torque references are converted into current references and phase currents are controlled using current controllers. This indirect way of controlling torque is not effective and results in a ripple in the torque. This paper proposes a direct instantaneous scheme in which reference torques are compared with estimated torques directly and the error is given to FOPID controller. The FOPID torque controller controls the motor torque effectively with a very low ripple. Here, FA technique is used to tune the FOPID parameters. Simulation results are verified in Matlab/Simulink environment and also the effectiveness of proposed FOPID controller is compared with GA based FOPID controller.

A Simple, Efficient, and Novel Standalone Photovoltaic Inverter Configuration With Reduced Harmonic Distortion

Abstract: This paper is put forward a novel photovoltaic (PV) inverter topology for maximum solar power utilization, which incorporates a new maximum power point tracking (MPPT) scheme based on shading pattern identification using the artificial neural network, single-input and multi-output (SIMO) converter, and multilevel inverter (MLI). The performance of the proposed MPPT scheme is benchmarked under partially shaded conditions. In continuation, the PV voltage is fed to the SIMO converter, where the converter produces four independent (V1, V2, V3 and V4) voltages with different magnitudes. The MLI converts the dc output voltage of the SIMO converter into ac to feed the utility, with reduced harmonic distortion. This MLI consists of eight switching devices and produces thirty one level ac output voltage with very less harmonic distortion. The salient feature associated with the proposed topology is that the proposed MPPT scheme extracts utmost power in any weather conditions and MLI feeds the utility. An experimental prototype is designed and developed to verify the performance of the proposed PV inverter topology. FPGA Spartan trainer kit is used to program pulses required for the MLI and converter of the proposed topology.

A comprehensive review on hybrid electric vehicles: architectures and components

Abstract: The rapid consumption of fossil fuel and increased environmental damage caused by it have given a strong impetus to the growth and development of fuel-efficient vehicles. Hybrid electric vehicles (HEVs) have evolved from their inchoate state and are proving to be a promising solution to the serious existential problem posed to the planet earth. Not only do HEVs provide better fuel economy and lower emissions satisfying environmental legislations, but also they dampen the effect of rising fuel prices on consumers. HEVs combine the drive powers of an internal combustion engine and an electrical machine. The main components of HEVs are energy storage system, motor, bidirectional converter and maximum power point trackers (MPPT, in case of solar-powered HEVs). The performance of HEVs greatly depends on these components and its architecture. This paper presents an extensive review on essential components used in HEVs such as their architectures with advantages and disadvantages, choice of bidirectional converter to obtain high efficiency, combining ultracapacitor with battery to extend the battery life, traction motors’ role and their suitability for a particular application. Inclusion of photovoltaic cell in HEVs is a fairly new concept and has been discussed in detail. Various MPPT techniques used for solar-driven HEVs are also discussed in this paper with their suitability.

Critical Review on PV MPPT Techniques: Classical, Intelligent and Optimisation

Abstract: Maximum power extraction from the photovoltaic (PV) system plays a critical role in increasing efficiency during partial shading conditions (PSC's). The higher cost and low conversion efficiency of the PV panel necessitate the extraction of the maximum power point (MPP). So, a suitable maximum power point tracking (MPPT) technique to track the MPP is of high need, even under PSC's. This study gives an extensive review of 23 MPPT techniques present in literature along with recent publications on various hardware design methodologies. MPPT classification is done into three categories, i.e. Classical, Intelligent and Optimisation depending on the tracking algorithm utilised. During uniform insolation, classical methods are highly preferred as there is only one peak in the P–V curve. However, under PSC's, the P–V curve exhibits multiple peaks, one global MPP (GMPP) and the remaining are local MPPs. Hence, Intelligent and Optimisation techniques came into limelight to differentiate the GMPP out of all LMPPs. Every MPPT technique has its advantages and limits, but a streamlined MPPT is drafted in numerous parameters like sensors required, hardware implementation, tracking in PSC's, cost, tracking speed and tracking efficiency. This present study aimed to address the advancement in this area for further research.

Voltage Source Multilevel Inverters With Reduced Device Count: Topological Review and Novel Comparative Factors

Abstract: Multilevel inverters (MLIs) have gained increasing interest for advanced energy-conversion systems due to their features of high-quality produced waveforms, modularity, transformerless operation, voltage, and current scalability, and fault-tolerant operation. However, these merits usually come with the cost of a high number of components. Over the past few years, proposing new MLIs with a lower component count has been one of the most active topics in power electronics. The first aim of this article is to update and summarize the recently developed multilevel topologies with a reduced component count, based on their advantages, disadvantages, construction, and specific applications. Within the framework, both single-phase and three-phase topologies with symmetrical and asymmetrical operations are taken into consideration via a detailed comparison in terms of the used component count and type. The second objective is to propose a comparative method with novel factors to take component ratings into account. The effectiveness of the proposed method is verified by a comparative study.