Browsing by Author "Yellasiri, Y."

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A capacitor based single source MLI with natural balancing and less component for EV/HEV application
(John Wiley and Sons Ltd, 2022) Aditya, K.; Yellasiri, Y.; Shiva Naik, B.; Nageswar Rao, B.; Panda, A.K.
Due to their remarkable performance, capacitor-based inverters have recently gained attention. Hence, a new capacitor-based multilevel inverter is presented in this paper for electric and hybrid electric vehicle (EV and HEV) applications. EV systems are quite well for their use of two-level inverters; however, the generated load voltage comprises substantial undesirable harmonic content. It is regarded as one of the most efficient methods since replacing a two-level inverter with a multilevel inverter improves the power quality despite significantly reducing total harmonic distortion. Therefore, the recommended filter dimension will also be minimized. A flurry of reliability concerns has arisen due to the increased number of devices, circuit complexity, and stress on the circuit devices. A nine-level voltage waveform is created with only ten IGBTs, a DC-Source, and two capacitors. In the proposed nine-level inverter, the capacitor voltage is balanced utilizing a simple control approach to regulate the flying capacitor (FC) voltages actively. Here described a simple logic gate-based pulse-width modulation technique that ensures capacitor power balancing. The proposed inverter operation and capability are validated by experimental results derived from a laboratory prototype. Finally, by contrasting the new and standard inverter topologies, the virtues of the suggested architecture by the number of devices and price of the equipment are highlighted, and it is a simpler structure that requires less space and footprint area. © 2022 John Wiley & Sons Ltd.
A Dual Boost Multilevel Inverter Circuit for Renewable Energy Applications
(Institute of Electrical and Electronics Engineers Inc., 2020) Bharadwaj, L.; Yellasiri, Y.; Shiva Naik, B.S.; Nageswar Rao, B.N.; Aditya, K.; Reddy, D.V.
To minimise the dependence on fossil-fuels, researchers focused on integrating renewable energy with different power electronic inverters. In that process multilevel inverters (MLIs) have gained more attention due to its impeccable advantages. In this work, a novel topology with boost ability, and reduced number of components is proposed. Capacitors used in the proposed structure possess self-balancing ability and the works competently under any loading condition. It is worthy to mention that the blocking voltage of proposed circuit is with in the limits of source voltage even with the dual boost. Sinusoidal pulse width modulation switching strategy technique is employed to get gating signals. Simulation using MATLAB is carried-out to assess the performance of proposed inverter. Further, the proposed circuit is compared with switched-capacitor (SC) based MLIs in terms of number of switches, and standing voltage to highlight the potential merits. Â© 2020 IEEE.
A Fault Tolerant Nine-level Inverter Topology with Full DC Utilization for Electric Vehicle Application
(Institute of Electrical and Electronics Engineers Inc., 2022) Aditya, K.; Yellasiri, Y.; Shiva Naik, B.S.; Nageswar Rao, B.N.
In this study, a fault-tolerant nine-level inverter architecture for an electric vehicle application is presented. Although the importance of two-level inverters [1] is well-known in EV applications, it contains significant unwanted harmonics for generated voltage. As replacing a two-level inverter proliferates the quality of power with a multilevel inverter, it is considered one of the efficient ways. Even though multilevel inverters' essence considerably reduces total harmonic distortion. Eventually, the size of the filter requirement also will minimize. Because of the increased device count and capacitor voltage balance issues, we have a slew of reliability concerns. As a result, a fault-tolerant nine-level inverter built by cascading H-Bridge [2] and modified T-type voltage source inverters [3] and a bidirectional switch are presented. With the tiniest changes in the switching combinations, the provided inverter topology can sustain system faults caused by the failure of the source and/or switching devices. Subsequently, When compared to standard nine-level inverters, it features fewer switching devices. The results are observed and validated with a hardware platform while the suggested system is simulated in a MATLAB/Simulink environment under standard and malfunctioning settings. Â© 2022 IEEE
A Fuzzy Logic Based Switching Methodology for a Cascaded H-Bridge Multi-Level Inverter
(Institute of Electrical and Electronics Engineers Inc., 2019) Azeem, H.; Yellasiri, Y.; Jammala, V.; Shiva Naik, B.S.; Panda, A.K.
In this letter, an unusual switching technique is implemented using a fuzzy logic approach. The proposed technique simplifies the conventional method by eliminating the traditional logic-gate design. The fuzzy logic pulse generator acts as a lookup table as well as a pulse generator. On the basis of the modulation index as input, controlled membership functions (MFs) and rules of the fuzzy logic controller open various possibilities of producing pulses directly. The proposed technique is evaluated on the cascaded multi-level inverter with symmetric and asymmetric operations using selective harmonic elimination pulsewidth modulation. MFs are designed on the basis of pre-calculated firing conditions for different modulation index values. Hardware verification is carried out to support the proposed switching technique. © 1986-2012 IEEE.
A Hybrid Nine-Level Inverter Topology with Boosting Capability and Reduced Component Count
(Institute of Electrical and Electronics Engineers Inc., 2021) Shiva Naik, B.S.; Yellasiri, Y.; Venkataramanaiah, J.; Panda, A.K.
Nowadays, output voltage boosting gain property along with curtailment in the circuit voltage stress, and component count are considered as the essential topological features for the new multilevel inverter (MLI) circuits. Recognizing the above, a hybrid nine-level inverter topology (HNIT) for DC-AC conversion is proposed in this brief. Each phase of the HNIT is designed with only eight semiconductor switches, one diode, and two electrolytic capacitors. Herein, series-parallel and conventional-series techniques are utilized effectively to balance the capacitor voltages. Further, cost and quantitative comparisons are carried among the state-of-art circuits to highlight the supremacy of proposed circuit. Subsequently, the performance of HNIT is verified experimentally with the fundamental switching PWM technique at different load conditions. © 2004-2012 IEEE.
A modified T-type multilevel inverter for renewable energy applications
(Elsevier Ltd, 2024) Nageswar Rao, B.; Yellasiri, Y.; Shiva Naik, B.S.; Aditya, K.; Panda, A.K.
The primary challenge in integrating renewable resources into grids using multilevel inverters (MLI) is the need for many separate DC sources and switching device counts. Transformer-based multilevel inverters (TMIs) have emerged to address this issue, aiming to minimize system components and boost source voltage with a single DC source. This research article introduces a novel TMI topology that utilizes only a single DC source and incorporates ten switches to produce good-quality load voltage with high magnitude. The proposed TMI offers several structural advantages, including self-galvanic isolation, reduced switching devices and uniform voltage levels across all turn ratios. Additionally, the TMI operates a switching method called pulse width modulation, which provides the gating pulses to all the power semiconductor devices in the proposed TMI. An experimental model has been created in a laboratory environment, and simulations are performed using the MATLAB/Simulink platform to assess the effectiveness of the suggested TMI. Furthermore, a comparison between the suggested TMI circuit and other recent TMI designs with similar characteristics is performed. This comparison is carried out to assess and validate the superior features of the proposed TMI over the alternative designs. © 2024 Elsevier B.V.
A new method for selecting optimum levels in asymmetric Cascaded H-Bridge-Multilevel Inveter with variable DC sources
(John Wiley and Sons Ltd, 2025) Venkataramanaiah, J.; Yadav, G.; Balaji, J.; Yellasiri, Y.
In general, cascaded H-bridge multilevel inverters (CHB-MLI) are typically operated with either symmetrical or asymmetrical input DC sources, set at predefined specific ratios such as binary (1:2) or trinary (1:3) in the case of asymmetry, to achieve the desired output voltage waveform. However, if any DC source fails to provide the predefined voltage magnitude, or CHB-MLIs with unspecified DC source ratios are utilized, the output voltage waveform may exhibit unequal magnitudes between consecutive levels, thereby causing a significant increase in total harmonic distortion (THD). Conventionally, to mitigate this effect, the corresponding H-bridge is bypassed through zero voltage switching, which leads to an additional burden on the remaining H-bridges to serve the same load. To reduce the burden on the remaining cells and improve the THD profile of the inverter, this article proposes a novel method for CHB-MLI with varying DC magnitudes. It aims to enhance the quality of the output voltage waveform by strategically selecting optimum voltage levels rather than utilizing all available levels when CHB-MLI has unspecified or variable DC sources. This approach can achieve a more balanced distribution of voltage magnitudes across successive levels by eliminating redundant states. Moreover, the proposed technique can reduce switch losses and enhance the converter's efficiency. The proposed method is validated through MATLAB/Simulink software simulations, followed by experimental verification. © 2024 John Wiley & Sons Ltd.
A new single-phase multilevel inverter with improved modulation technique
(John Wiley and Sons Ltd, 2023) Nageswar Rao, B.; Yellasiri, Y.; Shiva Naik, B.; Aditya, K.; K Panda, A.
This article proposes a seventeen-level (17L) inverter with a common leg configuration and an improved modulation technique. The proposed inverter uses only 10 switches, one toroidal core transformer, and one dc source. Therefore, the proposed design offers less control complexity with reduced cost and volume. Additionally, the suggested modulation technique improves the load voltage quality by minimizing the harmonic content. Simulation and laboratory studies are performed to confirm the proficiency of the suggested inverter with a new modulation technique. Further, a thorough comparison with recent transformer-based circuits is carried out to highlight the benefits of the proposed structure. © 2023 John Wiley & Sons Ltd.
A novel nine-level boost inverter with a low component count for electric vehicle applications
(John Wiley and Sons Ltd, 2021) Shiva Naik, B.S.; Yellasiri, Y.; Aditya, K.; Nageswar Rao, B.N.
In electric vehicles (EVs), considerable battery cells are cascaded in series for motor driving to improve the output voltage. The series combination of battery cells causes challenges like isolation of faulty cells, voltage unbalance, and slow charge equalization. Therefore, state-of-charge (SOC) and voltage equalization circuits are often used in industries to protect the battery cells. A nine-level inverter circuit with a double voltage boost is proposed to reduce the above issues based on the switch-capacitor (SC) principle. Unique features like self-balancing, voltage boosting are attained, which cannot be achieved through traditional inverters. The proposed topology can operate at a wide range of modulation indices ((Formula presented.)) to produce different voltage levels. The absence of a back-end H-bridge in the proposed circuit offers low voltage stress across the semiconductors. The operating principle, capacitor sizing, and modulation approach are presented. Further, experimental tests are conducted at different loading conditions to verify the performance of the proposed circuit. © 2021 John Wiley & Sons Ltd.
A novel nine-level inverter with reduced component count using common leg configuration
(Springer Science and Business Media Deutschland GmbH, 2023) Nageswar Rao, B.; Yellasiri, Y.; Shiva Naik, B.S.; Aditya, K.
This article proposes a nine-level (9 L) inverter with a common leg configuration employing transformers and a single dc source. The suggested inverter uses eight switches and two transformers to produce 9 L output voltage. The suggested circuit minimizes the switches and transformers compared with existing transformer-based multilevel inverters (TMLI). Therefore, the proposed circuit cost, volume and complexity are also reduced. Additionally, a thorough comparison with the various 9 L inverter circuits is conducted to ensure the benefits of the suggested TMLI. A basic logic gate-based pulse width modulation (PWM) is implemented for the suggested 9 L inverter. Simulation and hardware studies verifying the feasibility and proficiency of the suggested inverter are performed. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
A Novel Quadruple Boost Inverter With New Optimized Fuzzy-Based Switching Scheme
(Institute of Electrical and Electronics Engineers Inc., 2024) Aditya, K.; Yellasiri, Y.; Shiva Naik, B.S.; Nageswar Rao, B.N.; Panda, A.K.
This brief proposes a novel quadruple boost nine-level inverter (QB-NLI) and an optimized switching pattern using fuzzy logic controller. The suggested method simplifies the traditional approach by removing the conventional logic gate circuit design. The pulse signal generator and lookup table are both derived using a fuzzy logic pulse generator. Fuzzy logic controller (FLC) and Controlled membership functions (MFs) rules open numerous prospects for generating pulses based on the input as modulation index. The suggested technique is examined on the proposed QB-NLI topology using the selective harmonic elimination PWM method. MFs are created based on averaging Newton Rapson and quantizer firing angles for diverse modulation index (mi) values. The proposed QB-NLI structure comprises ten switches with one dc-voltage source and two capacitors. The proposed structure's circuit description, modes of operation, proper component selection, and a new fuzzy-based switching scheme are presented. Further, a discussion about the comparative analysis of the proposed switching technique with other switching techniques concerning THD and RMS voltages is presented. In addition to the simulation results, experimental tests are conducted under various load conditions on the built-in hardware prototype to evaluate the proposed QB-NLI structure and switching technique. © 2023 IEEE.
A Novel Seven level inverter with Common-Leg Configuration by Employing Transformers
(Institute of Electrical and Electronics Engineers Inc., 2022) Nageswar Rao, B.; Yellasiri, Y.; Shiva Naik, B.S.; Aditya, K.
This paper proposes a new multilevel inverter with a common leg structure using three transformers and eight power semiconductor devices. The intended configuration contains of one traditional H-bridge and two half bridges supplied from a single dc source. The switching power circuit powered three transformers with series connections, which produced seven levels (3VDC, 2VDC, VDC, 0, -VDC, -2VDC, -3VDC) at the inverter output from the source VDC. Further, this circuit demonstrates the benefit of fewer switches and drivers in comparison to the traditional circuits for the production of the same load voltage levels. Thus, the suggested topology complexity, volume, and cost are reduced. Finally, the effectiveness of the suggested inverter is performed using MATLAB, and the simulation studies are incorporated. Â© 2022 IEEE.
A novel single source multilevel inverter with hybrid switching technique
(John Wiley and Sons Ltd, 2022) Nageswar Rao, B.; Yellasiri, Y.; Shiva Naik, B.; Venkataramanaiah, J.; Aditya, K.; Panda, A.
A novel multilevel inverter (MLI) configuration with the hybrid switching technique is presented in this paper. The proposed MLI consists of the H-bridge combination with unidirectional switches, half-bridges, and transformers. The suggested MLI with the additional cascaded connection increases to higher voltage levels. The number of employed components in this topology is drastically minimized. Therefore, the complexity, cost, and volume of the proposed topology are also reduced. The operation of the suggested topology is tested through the improved novel switching technique. This modulation method reduces the total harmonic distortion (THD) and produces high root mean square (RMS) voltage. Further, a comprehensive comparison with the recent MLI topologies is performed to validate the merits of the suggested inverter. Simulation and experimental results verify the suggested topology performance using the new modulation technique at different loading conditions and modulation indices. © 2021 John Wiley & Sons, Ltd.
A Novel Switched-Capacitor Boost Multilevel Inverter for PV Applications
(Institute of Electrical and Electronics Engineers Inc., 2020) Reddy, D.V.; Yellasiri, Y.; Shiva Naik, B.S.; Nageswar Rao, B.N.; Aditya, K.; Bharadwaj, L.
Nowadays, voltage boosting capability with less part count has become the key feature of recently developed MLI topologies. In this work, a novel topology with boost ability, and reduced number of components is proposed. Capacitors used in the proposed structure possess self-balancing ability and the works competently under any inductive-resistive loading conditions. The blocking voltage of proposed circuit is with in the limits of source voltage even with the dual boost. Sinusoidal pulse width modulation switching strategy technique is employed to get gating signals. Simulation using MATLAB is carried-out and hardware tests are conducted with the available components to assess the performance of proposed inverter. Further, the proposed circuit is compared with switched-capacitor (SC) based MLIs in terms of number of switches, and standing voltage to highlight the potential merits. Â© 2020 IEEE.
A review on symmetric, asymmetric, hybrid and single DC sources based multilevel inverter topologies
(Elsevier Ltd, 2017) Venkataramanaiah, J.; Yellasiri, Y.; Panda, A.K.
In recent past, multilevel inverters(MLIs) are treated as sophisticated power conversion systems demanded for high power medium voltage applications. The aim of this article is to review on recent examined multilevel inverter topologies which can be classified into four groups according to the DC voltage supplied to each fundamental unit and/or arrangement of non-identical fundamental units in an one configuration: Symmetric, Asymmetric, Hybrid and Single DC source topologies. In each group, several new versions have been constructed for last few decades. In this study the position (design and functionality) of each and every topology and also every group are reviewed. Further, a special attention is focused on Single DC source MLIs. Finally at the end of the review, merits, limitations and adequate applications are clearly mentioned. Thus, present review provides complete overview among newly developed multilevel inverters. © 2017 Elsevier Ltd
A Single DC-source Asymmetrical Multilevel Inverter With Solid State Transformer With New Switching Approach
(Institute of Electrical and Electronics Engineers Inc., 2024) Karunakaran, E.; Yellasiri, Y.; Nageswar Rao, B.N.; Vivek, P.S.S.; Aditya, K.
Cascaded H-bridge (CHB) MLI have emerged as the preferred choice due to their high quality in output waveforms with low harmonic distortion. However, a key limitation in these inverters lies in the requirement of a dedicated DC source for each bridge. To overcome this challenge, there is a transition towards asymmetrical cascaded H-bridge (ACHB) MLIs, enabling the use of a variable DC source for each bridge. The variability in DC supply is achieved through a high-frequency link. This paper introduces a novel optimized switching technique for asymmetrical cascaded H-bridge (ACHB) MLIs with a single DC input incorporating a high-frequency link (HFL). The effectiveness of the suggested approach in achieving a 27-level asymmetric multilevel inverter is substantiated by experimental outcomes obtained through MATLAB/Simulink simulations. Â© 2024 IEEE.
A Single Source Self-Balanced Boost MLI with Reduced Part Count for EV Applications
(MDPI, 2023) Aditya, K.; Yellasiri, Y.; Kumar, R.D.; Shiva Naik, B.S.; Nageswar Rao, B.; Dhanamjayulu, C.
As the use of inductor-based topologies demands a large amount of space, capacitor-based topologies have garnered attention. Electric Vehicles (EVs) are usually equipped with two-level inverters, which require separate control strategies for each level and synchronizing the strategies increases the complexity of operation and makes them unreliable. Therefore, a single-stage converter with boost and conversion abilities with better power quality at optimal component count and efficiency is needed. A novel capacitor-based boost multilevel inverter (CB-MLI) topology is proposed in this paper as it is found suitable for EV and HEV applications. It is capable of generating an eleven-level waveform with only eleven switches, three capacitors, and a single isolated source. The self-balancing property of the capacitors makes the topology one of a kind. A constant carrier PWM-based control strategy is utilized to switch the IGBTs. Testing results from hardware setup confirm the proposed capacitor-based CB-MLI topology operating modes and potentiality. Lastly, by highlighting the proposed and existing MLI circuits, the benefits of the recommended configuration are outlined by component count and total cost. Additionally, it is a simplified design that needs fewer footprint areas and space. © 2023 by the authors.
A Single Stage Switched-Capacitor Hexad Boost Multilevel Inverter Featuring Boost Ability
(Institute of Electrical and Electronics Engineers Inc., 2020) Shiva Naik, B.S.; Yellasiri, Y.; Venkataramanaiah, J.
Nowadays, curtailment in the number of dc sources, circuit component count along with the boosting gain property of the output voltage are considered as the essential topological features for the new multilevel inverter (MLI) structures. Considering the above, a novel 13-level single-stage switched-capacitor hexad boost (S3 CHB) inverter featuring boosting gain and self-balancing ability is proposed in this paper. Each phase of the proposed \mathrm{S}^{3} CHB-MLI is designed with only 14 semiconductor switches and three electrolytic capacitors. Here, the capacitors' voltages are balanced automatically by utilizing the series-parallel technique effectively. An absence of H-bridge at the back-end makes the circuit to extend for higher levels. Capacitors' voltage ripple are analyzed in detail. Further, a cost comparison is conducted among the state-of-art MLIs to highlight the superiority of the proposed configuration. Finally, the effectiveness of the proposed \mathrm{S}^{3} CHB circuit is experimentally demonstrated. Results at different load conditions are captured to prove the inductive load capability. Â© 2020 IEEE.
A single-source nine-level boost inverter with new optimal switching scheme for EV applications
(John Wiley and Sons Ltd, 2024) Aditya, K.; Yellasiri, Y.; Shiva Naik, B.; Nageswar Rao, B.; Panda, A.K.
The importance of two-level inverters is well known in EV applications; it contains significant unwanted harmonics in generated voltage. One of the most efficient way to increase power quality is to replace a two-level inverter with a multilevel inverter (MLI). The MLI's essence considerably reduces total harmonic distortion. Eventually, the size of the filter requirement also will minimize. Because of the increased device count and capacitor voltage balance issues, these converters have a slew of reliability concerns. To mitigate these drawbacks, a novel switched-capacitor based nine-level inverter (SC-NLI) structure with a new optimal control switching technique for electric vehicle (EV) applications is proposed in this paper. The proposed SC-NLI structure comprises 10 switches, one diode, and two capacitors. The proposed structure's circuit description, modes of operation, proper component selection, and a new optimal switching scheme are presented. A discussion about the comparative analysis of suggested topology with currently developed MLI structures is presented. In addition, to the simulation results, experimental tests are conducted under various load conditions to evaluate the proposed SC-NLI structure. © 2023 John Wiley & Sons Ltd.
An effective standalone hybrid wind-photovoltaic water pumping system with reduced power converter count
(John Wiley and Sons Ltd, 2021) Angadi, S.; Yaragatti, U.R.; Yellasiri, Y.; Raju, A.B.
This article proposes a standalone hybrid wind-photovoltaic (PV) water pumping system (WPS) with minimal power electronics interface, simple composite control, and optimal energy management strategy (EMS) for effective utilization of both renewable sources. The proposed system consists of classic Perturb and Observe (P&O) algorithm applied to the boost converter of the solar PV system and voltage regulation algorithm/hill-climbing MPPT algorithm with zero steady-state oscillation (ZSSO) applied to bidirectional voltage source converter (VSC) of wind energy conversion systems (WECS) for optimal power extraction at all times. The constant voltage to frequency (V/F) ratio is ensured at the point of common coupling (PCC) for the entire operating range to avoid saturation in the self-excited induction generator (SEIG) and the induction motor (IM) pump. The energy management strategy is devised to effectively harness renewable energy from both sources while ensuring the DC-link voltage stability. The system forms compelling proposition, given the least converter count to integrate solar-PV and wind energy employing easy to implement control algorithms with optimal energy extraction. The results of simulation and experimental studies on the proposed system reveal the effectiveness of the composite controller in terms of energy utilization, constant flux operation, and power balance for the entire operating range. Additionally, system exhibits acceptable dynamic and steady-state behavior against variations in wind velocity, solar irradiation, and load. © 2021 John Wiley & Sons Ltd.