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Item Energy management and charging portfolio analysis for future battery powered harbor vessels /(IEEE, 2023-05-11) Ramesh, U. S.This article intends to provide key insights to the marine designers and port authorities for adapting battery-operated zero emission electric harbor vessels (ZEE-HVs) and plan the resources for charging infrastructure. The present study is a cumulatively coordinated analysis of various significant aspects concerning the adaptation of ZEE-HVs for short-endurance commercial maritime operations. The sizing of onboard battery energy systems (OBES) is discussed for different short-endurance ZEE-HVs by considering the speed-resistance characteristics of the hull and open-water characteristics of the propeller without limiting their operations for specific load profiles/operating cycles. Charging portfolio selection is critical for a marine vessel as the OBES size is several times higher than a regular electric vehicle's battery. Hence charging portfolio selection criteria are presented to select a suitable battery charging protocol for each ZEE-HV as per the OBES ratings and available idle times on a typical day. Since the port is a commercial spot, uncertainty in resource planning leads to penalties and loss of goodwill. Therefore, Monte Carlo-based iterative analytical method is adopted to forecast the ZEE-HVs' maximum possible charging power demand on a typical day. By the load forecast data, optimal sizing of the load peak shaving battery (LPSB) was performed to limit load fluctuations at the port grid. The synergy of ZEE-HVs with LPSB and bi-directional charge-discharge controller is pivotal for effectively administering the seaport shore charging facility, which is demonstrated for a typical energy management cycle.Item Energy management and charging portfolio analysis for future battery powered harbor vessels /(IEEE, 2020-12-16) Ramesh, U. S.The growth in Battery Powered Harbor Vessels (BPHV) signifies the necessity for a study on charging infrastructure and energy management at the seaport. This paper analyzes the charging portfolio specifications and energy management for different types of prospective BPHV at Visakhapatnam port. A brief study was conducted to identify the suitable charging method for regularly operated BPHV like Mooring Launch (ML), Pilot Launch (PL), Fishing Vessel (FV), and Tug Boats (TB). An iterative analytical study is characterized to forecast the BPHV charging load demand over a 24-hour duration and performed optimal sizing of Shore Battery Bank (SBB) to shave the critical load peaks and limit load fluctuations at the port grid. The energy management at the prospective seaport charging infrastructure is presented with relevant results by discussing the significance of Active Line Conditioner (ALC) and Bidirectional DC-DC Converter (BDC).Item Sizing of energy storage system for a battery operated short endurance marine vessel /(IEEE, 2020-01-01) Ramesh, U. S.Conventional marine vessels are operated by either diesel or diesel-electric propulsion which results in the production of harmful emissions that affect the lives inhabiting near the harbor. By employing the Battery-operated Electric Propulsion (BEP) system, harmful emissions released by marine vessels will be reduced to zero. In this study, a harbor tugboat with 30 tonne weight carrying capacity, maneuvering at 9 knot speed is considered for the sizing of BEP. The effective power demanded by the marine vessel when operating at rated speed with full weight is calculated from the hydrostatic and speed power analysis, and the designing of a suitable propeller is discussed. The power train is presented with the calculation of power rating for each component of BEP. Battery count and its total weight are evaluated with different types of Li-ion batteries which are commercially used in electric vehicles and a suitable one is identified for BEP application. Sizing of the supercapacitor for DC link and battery buffer is presented. For the short endurance operation of a marine vessel, the weight of the battery based energy storage system (ESS) is compared with the conventional diesel-electric generator.Item Underwater noise levels in Indian waters off the coast of Mormugao Port /(Taylor & Francis, 2019-06-25) Kumar, G. V. V. Pavan; Ramesh, U. S.Among various factors influencing the ocean noise levels, shipping traffic radiated underwater noise levels were identified as the major contributors. The increase in ambient noise levels due to natural and anthropogenic sources threatens the marine species communication. India has a coastline of 7,516.6 Km with 12 major and ∼187 minor ports. The hydrophone system measured for 39 days helped in investigating the distant shipping traffic lane noise levels and its influence on ambient noise levels of the region. The ocean noise levels measurement were ∼115 dB re 1 µPa for the prevailing environmental conditions. The noise exposure levels were ∼10 dB higher at <1 kHz due to ship passage to and from the port. The fish noise dominated the ambient sea noise mostly at high frequencies >1 kHz. The maximum and minimum range of shipping noise spectra for both the month’s data indicated peak sound pressure level in the lower frequency. Thus, the outcome of the measurements helped in understanding ocean noise levels off the coast of Mormugao Port and the influence of shipping traffic. A similar study for longer duration shall be useful to develop specific traffic lanes in the port entrance which is free from the mammal movements.Item Optimization with load prediction in asynchronous generator driven tugboat propulsion system /(IEEE, 2017-12-01) Ramesh, U. S.Mostly tugboats are powered by diesel-electric generators for meeting power of auxiliary loads and of electric motors for propulsive load. This paper proposes the optimal fuel management in diesel-electric generators considering doubly fed asynchronous machine (DFAM) as generator. An optimization problem is formulated to schedule the available power sources aiming for best possible fuel efficiency. The performance of optimal control strategies critically depends on future load applied in generator. Considering this for predicting tugboat load demand a simple predictive methodology is proposed based on the average mode time per cycle. The proposed control mechanism is able to respond to any sudden load change and also to emergency halt condition. DFAM as generator is considered for improving the system efficiency at low load region. Speed of the diesel engine is decided by the load demand. Output voltage and frequency of DFAM at variable speeds are regulated by power electronic convertors, connected in rotor circuit.Item Control strategy for fuel saving in asynchronous generator driven electric tugboats /(IEEE, 2016-01-01) Ramesh, U. S.Usually electric tugboats are equipped with diesel engine based electric generator for power production, battery for supplying power to auxiliary loads and electric motors for propulsion. This paper proposes control strategies for diesel engine and electric generators used in electric tugboat to improve energy efficiency of the system. Doubly fed induction machine (DFIM), asynchronous in nature, is considered in this research which serves as generator (power production). The speed of diesel engine is controlled in accordance with the power demanded by the tug. Output voltage and frequency of generator during sub-synchronous operation are regulated by controlling its rotor current with the help of power electronic convertors. Comparison of fuel consumption at fixed and variable speeds of operation is performed. From the test results, it is observed that the variable speed operation of diesel generator offers significant reduction in fuel consumption.Item Improved Fuel-Use Efficiency in Diesel–Electric Tugboats With an Asynchronous Power Generating Unit(IEEE, 2019-03-20) Ramesh, U. S.High capacity diesel-electric tugboats are employed at every modernized harbor for assisting big marine vessels and other harbor applications. Contemporary tugboats use multiple power sources to meet their propulsion and auxiliary on-board load demands. The effective utilization of multiple power sources leads to better fuel use efficiency with reduced emissions, economic, and environmental benefits. This paper presents a simple optimization technique for scheduling available power sources of a diesel-electric tugboat [diesel engine generators (DEGs) and batteries] to meet its load demand with an objective to minimize fuel consumption. For this paper, a diesel-electric tugboat system of 1.1-MW capacity with different generating systems is considered: 1) fixed speed generating unit (2 × 550 kW fixed speed DEG employing synchronous generators) and 2) variable speed generating unit [1×1.1 MW variable speed DEG employing doubly fed induction generator (DFIG)]. From the optimized test results, it is inferred that the variable speed generating unit offers a fuel saving of 29.86% in comparison with diesel-mechanical propelled system and 2.9% in comparison with fixed speed diesel- electric system. The simulation of a 1.1-MW variable speed generating system is performed in MATLAB/Simulink 2014A environment, and experimental demonstration is performed through a 2.2-kW laboratory prototype.Item Improved fuel-use efficiency in diesel–electric tugboats with an asynchronous power generating unit(IEEE Transactions On Transportation Electrification, 2019) Anil Kumar, Birudula; Raghu, Selvaraj; Thanga Raj, Chelliah; Ramesh, U. S.High capacity diesel–electric tugboats are employed at every modernized harbor for assisting big marine vessels and other harbor applications. Contemporary tugboats use multiple power sources to meet their propulsion and auxiliary on-board load demands. The effective utilization of multiple power sources leads to better fuel use efficiency with reduced emissions, economic, and environmental benefits. This paper presents a simple optimization technique for scheduling available power sources of a diesel–electric tugboat [diesel engine generators (DEGs) and batteries] to meet its load demand with an objective to minimize fuel consumption. For this paper, a diesel–electric tugboat system of 1.1-MW capacity with different generating systems is considered: 1) fixed speed generating unit (2 × 550 kW fixed speed DEG employing synchronous generators) and 2) variable speed generating unit [1×1.1 MWvariable speed DEG employing doubly fed induction generator (DFIG)]. From the optimized test results, it is inferred that the variable speed generating unit offers a fuel saving of 29.86% in comparison with diesel-mechanical propelled system and 2.9%in comparison with fixed speed diesel– electric system. The simulation of a 1.1-MW variable speed generating system is performed in MATLAB/Simulink 2014A environment, and experimental demonstration is performed through a 2.2-kW laboratory prototype