Sai Srinivas Manohar

National University of Singapore

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Sanjib Kumar Panda

National University of Singapore

Aravinth Subramaniam

National University of Singapore

Jaydeep Saha

National University of Singapore

Animesh Sahoo

Birla Institute of Technology and Science, Pilani - Goa Campus

Prasanth Sundararajan

National University of Singapore

Elango Jeyasankar

National University of Singapore

Sivakumar Nadarajan

Alliance University

Rahul Bhujade

National University of Singapore

Amit Kumar Gupta

Indian Institute of Technology Bhubaneswar

Subash Chandar Athikessavan

National University of Singapore

Cooperative Institutions

National University of Singapore

Nanyang Technological University

Agency for Science, Technology and Research

Institute of Microelectronics

Indian Institute of Science Bangalore

Weatherford College

Singapore-MIT Alliance for Research and Technology

University of California, Berkeley

Nazarbayev University

Persian Gulf University

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Inter-Turn Fault Detection of Dry-Type Transformers Using Core-Leakage Fluxes

IEEE Transactions on Power Delivery (2018)

Subash Chandar Athikessavan Elango Jeyasankar Sai Srinivas Manohar Sanjib Kumar Panda

In this paper, a new technique for low-severity inter-turn fault detection under online operating conditions of dry-type transformers is proposed. The proposed methodology requires just two inexpensive flux sensors and is based on the fundamental component of the core-leakage fluxes at the transformer's outer limbs. Theoretical analysis using the proposed analytical models and experimental validation on a 10-kVA experimental prototype transformer are carried out to evaluate the performance of the proposed methodology under various fault severities. The real-time fault-detection capability of the proposed technique is also evaluated using a fabricated prototype health monitoring device, which reveals that as low as 2-turns bolted fault out of 150 turns can be detected within 3 fundamental cycles. The methodology is immune to loading and supply voltage unbalance conditions and on par with the classical differential negative sequence current based technique with an additional advantage of 78% reduction in the total number of sensors required for a three-phase three-winding transformer.

Magnetic Flux Leakage

Leakage (economics)

10.1109/tpwrd.2018.2878460

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Citations (23)

Fault diagnostic techniques for induction machines through finite element analysis

2021 24th International Conference on Electrical Machines and Systems (ICEMS) (2017)

Aravinth Subramaniam Animesh Sahoo Sai Srinivas Manohar Sanjib Kumar Panda

Electrical and mechanical faults in a three phase Induction machine is modelled and analysed, to identify potential fault signatures. Electrical, magnetic and torque signatures are analysed for various faults and their combinations, for potential fault signature identification. A multi-physics Finite Element tool is chosen for this analysis considering the possibilities to extend the study to thermal and structural analysis.

Signature (topology)

Identification

10.1109/icems.2017.8056357

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Citations (6)

Transformer Winding Fault Diagnosis by Vibration Monitoring

2018 Condition Monitoring and Diagnosis (CMD) (2018)

Sai Srinivas Manohar Aravinth Subramaniam Mehdi Bagheri Sivakumar Nadarajan Amit Kumar Gupta

The role of transformer in electricity network reliability and safe operation is quite crucial. Therefore, their monitoring, maintenance and management is vitally important for utility operators. Simpler, non-invasive and online condition monitoring method which is sensitive to incipient faults is in demand for transformer diagnosis. Although vibration monitoring is considered as a valuable technique in industry for rotating machines, it is least explored for static electrical equipment such as transformer. In this study, core and winding vibrations in a dry type transformer is monitored using an accelerometer to diagnose the winding electrical and mechanical faults. Winding and core vibrations for various degrees of inter-turn fault, axial movement and disc displacement under different load conditions are studied.

Condition Monitoring

10.1109/cmd.2018.8535726

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Citations (7)

Highly Efficient and Power-dense GaN-Based Drive-train Inverter for Light Electric Vehicles

Jaydeep Saha Rahul Bhujade Prasanth Sundararajan Sai Srinivas Manohar Sanjib Kumar Panda

Electric light

Wide-bandgap semiconductor

10.1109/ipemc-ecceasia60879.2024.10567920

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Citations (0)

Condition monitoring of power electronic converters in power plants — A review

2021 24th International Conference on Electrical Machines and Systems (ICEMS) (2017)

Sai Srinivas Manohar Animesh Sahoo Aravinth Subramaniam Sanjib Kumar Panda

In terms of power supplies and power conversion, power electronics based converters have their own advantages. Proper condition monitoring for power electronic converter has become necessary which is now in incipient stage. This paper includes different kinds of failure modes associated with power electronics at the converter as well as device level and recent Condition Monitoring (CM) techniques to detect those faults at the earliest stage. Proper reliability improvement has to be performed on power electronic systems so that they could be more resistive to different aspects such as safety, cost and availability. Power semiconducting devices are considered to be the most sensitive part of the power electronic systems and the main causes of stresses on these devices could be initiated due to the atmospheric conditions as well as short duration heavy loads, which should be considered during power electronic system design and normal operation as the consequences of these can't be felt at the initial stage which demands conservative converter design.

Power Electronics

Power module

Commutation cell

Electronic component

10.1109/icems.2017.8056371

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Citations (54)

Device Agnostic Intelligent Gate Driver for Condition Monitoring of Power Devices in AC Drives

Prasanth Sundararajan Jaydeep Saha Sai Srinivas Manohar Sanjib Kumar Panda Mohamed Halick Mohamed Sathik

The reliability of power electronic converters is an important area of concern due to their increased use in many safety-critical and mission-critical applications. Condition monitoring of power electronic converters is crucial to plan for wear-out failures in advance and to ensure their availability. Power devices such as silicon (Si)-based metal oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), and silicon carbide (SiC)-based MOSFETs are widely used as switching devices in medium power level converters. These devices are controlled by gate drivers which take low power signal as input and generate high current signal to operate the power devices. In this paper, a device agnostic intelligent gate driver for industrial ac drives is proposed. It can extract precursor parameters such as collector-emitter threshold voltage and on-state resistance for IGBTs, and on-state resistance for silicon and silicon carbide MOSFETs to monitor its health. The major advantages of the proposed methodology are its ability to capture the device current samples from load current and its ability to differentiate device degradation into chip degradation and package degradation. Another notable feature is that it can work with low sampling rates of less than 1 kHz. The effectiveness of the proposed method to extract various device degradation related parameters is demonstrated through simulation results and experiments.

Gate driver

Power MOSFET

Insulated-gate bipolar transistor

10.1109/pedes56012.2022.10080683

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Citations (1)

A Review on the Design Considerations for Next-Generation e-Motorbike Drive-Train Inverter

IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society (2023)

Jaydeep Saha Bin He Sai Srinivas Manohar Rahul Bhujade Gongyue Tang

Though e-motorbikes comprise a considerable proportion of electric vehicles (EVs), it's drive-train design is rarely presented in the literature. This paper focuses on reviewing the important design considerations for drive-train inverters of next-generation e-motorbikes. A compilation of state-of-the-art e-motorbikes' specifications reveals that the inverter requirements are diverse in terms of power with a thrust towards enhanced efficiency and power density. A review of the power-electronic design of this inverter is presented to elicit the topology choices, battery-pack design based on DC-link voltage choice, as well as the benefits of using new wide-bandgap devices and latest ceramic capacitors. An overview of the inverter's cooling system design shows the merits of liquid-cooling for compact inverter design.

10.1109/iecon51785.2023.10312207

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Citations (6)

Switchgear Condition Assessment and Lifecycle Management: Standards, Failure Statistics, Condition Assessment, Partial Discharge Analysis, Maintenance Approaches, and Future Trends

IEEE Electrical Insulation Magazine (2021)

Aravinth Subramaniam Animesh Sahoo Sai Srinivas Manohar Santosh Janaki Raman Sanjib Kumar Panda

In this article, switchgear standards, failure statistics, and condition assessment methods with a special focus on medium and high voltage classes are critically reviewed.

Switchgear

Maintenance engineering

10.1109/mei.2021.9399911

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Citations (32)

Condition Monitoring framework for Converter Transformers used in Marine Electric Propulsion

Aravinth Subramaniam Sai Srinivas Manohar Saurabh Bhandari Sivakumar Nadarajan Amit Kumar Gupta

Electrical and magnetic domain parameters for online condition monitoring of converter transformers used in marine power system is explored, where the traditional DGA and PD techniques are not much applicable. Current signal and leakage flux from transformer core and winding are studied, with an emulated inter-turn fault in a 10 kVA lab-scale converter transformer. It is expected that the presence of valve winding in converter transformer will pose a challenge, for condition monitoring as it has inherent harmonics. There is a need for an online monitoring technique which is simple, cost effective and rugged to diagnose the fault and raise an alarm on-board ship, as it may lack the right maintenance technician or a replacement transformer during the voyage. Method of emulating the inter-turn fault in transformer, experimental studies and the frequency domain results from electrical and magnetic sensors for condition monitoring are discussed.

Condition Monitoring

Energy efficient transformer

10.1109/pedes.2018.8707737

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Citations (3)

Diagnosing Axial Movements in Transformer Windings by Leakage Flux Monitoring

2018 Condition Monitoring and Diagnosis (CMD) (2018)

Aravinth Subramaniam Pritam Mukherjee Sai Srinivas Manohar Sanjib Kumar Panda

Monitoring transformers is essential to ensure reliable operation of a power system as they are possibly the most critical equipment present in all generation, transmission, and distribution network. Having such monitoring amenable for online implementation is even more desirable. Mechanical deformations are difficult to detect with existing online condition monitoring tools as they hardly lead to any perceivable change in quantities that can be measured from terminals. Leakage flux, amongst all the power frequency parameters, is the most sensitive to changes in winding geometry. Understanding how the spatial distribution of leakage flux is altered by winding deformation would help in diagnosing such damages, preferably at their infancy, by means of flux sensors mounted along the axial height of a winding. As a preliminary study, only axial movements in the winding are considered in this paper. A Finite Element model was developed in Ansys Maxwell to emulate various degrees of axial movement at different places in the winding. The aspects of leakage flux based online winding damage diagnosis at their incipient stage, are investigated in detail with the computed leakage flux distribution and their results presented.

Magnetic Flux Leakage

Leakage (economics)

Condition Monitoring

Power transmission

10.1109/cmd.2018.8535713

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Citations (4)