Khosru Salim | Independent University, Bangladesh (original) (raw)

Papers by Khosru Salim

Proceedings of the IEEE 1999 International Conference on Power Electronics and Drive Systems. PEDS'99 (Cat. No.99TH8475), 1999

Abstract - Fuel cell is an alternative power generation method which is envisaged to be environme... more Abstract - Fuel cell is an alternative power generation method which is envisaged to be environmental friendly and efficient. It can be an attractive solution for various clean power applications such as electric vehicle. It can also suitably used as a stand alone power generator. Fuel cell ...

2022 International Conference on Engineering and Emerging Technologies (ICEET)

2020 IEEE Region 10 Symposium (TENSYMP), 2020

Readymade Garments (RMG) sector in Bangladesh has rapidly attained high importance for a high con... more Readymade Garments (RMG) sector in Bangladesh has rapidly attained high importance for a high contribution to GDP for more than the last 30 years. 80% of the motor used in these industries for sewing machines are inefficient clutch motors. As a result, these RMG sectors suffer from huge power loss from the very beginning. An efficiency improved device can make huge differences in power consumption and energy savings annually. This paper shows a clear scenario of the RMG sector's annual power consumption data and power losses due to inefficient devices. A single-phase Variable Frequency Drive (VFD) based efficient sewing machine is also presented here. Annual statistical analysis on the energy efficiency and savings of energy-efficient sewing machines is carried out to provide a clear image of energy losses and possible energy savings of the last 10 years in the RMG sector of Bangladesh. A case study is also presented after implementing a VFD based energy efficient sewing machine by showing the possible economic benefits.

一般社団法人電子情報通信学会, Mar 6, 2009

2021 2nd International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST), 2021

This paper presents a solar-powered DC/AC drivetrain design for an electric boat with a portable ... more This paper presents a solar-powered DC/AC drivetrain design for an electric boat with a portable irrigation system. The optimal boat has 35 PV modules each of 95W (total 3. 3kW), 20 Lead-Acid batteries of 12V90Ah (total 21kWh) as power sources. An induction motor (IM) of 5HP to run the boat and a pump of 3HP for irrigation are the primary loads of the drivetrain. Two 3-phase inverters will control the IM motors. On the storage side, a bi-directional buck-boost converter controls the charging and discharging process. These three controllers operate in MPPT (Maximum Power Point Tracking) mode to capture maximum energy from the solar array that provides 300V of DC optimum transmission voltage. A steel-wooden boat fabricated to carry 100 peoples with the PV modules on the rooftop. The boat’s maximum speed is 5 knots, with a total duration of cruising on a sunny day is around 10 hours. The pump used to irrigate surface water to cover 4 acres of land daily. The performance was justified by the practical implementation to a countryside river.

2018 International Conference on Recent Innovations in Electrical, Electronics & Communication Engineering (ICRIEECE), 2018

Irrigation plays a major role in food security all over the world. In rural areas, single-phase p... more Irrigation plays a major role in food security all over the world. In rural areas, single-phase power is mostly available, which is why most irrigation systems consist of single-phase induction motors. The performance of these systems depends heavily on the quality of power available. Often times, the voltage delivered to the load is lowered due to transmission line drops and inadequate power generation. As a result, the current drawn by the loads increases and system efficiency falls. This paper presents the experimental findings of two single-phase submersible pump systems in which the voltage supplied has been varied. In one of the systems, the effects on system performance of incorporating a single-phase variable frequency drive (VFD) before the power reaches the load is investigated. A comparison between input power and flowrate has been made for each system. It is seen from the results that the flowrate at any particular input power is greater for the system with VFD, implying...

2020 11th International Conference on Electrical and Computer Engineering (ICECE), 2020

This paper presents a circuit topology for portable Shielded Metal Welding Machine (SMAW) integra... more This paper presents a circuit topology for portable Shielded Metal Welding Machine (SMAW) integrated by soft-switching PWM full-bridge dc-dc power converter that can work with both utility grid 220Vac or solar DC 300Vdc as the input source. The power circuit maintains zero voltage switching (ZVS) to reduce switching losses. This technique leads the circuit to operate at a high switching frequency of 20 kHz. High switching frequency with the softer Pulse width modulation (PWM) converter, the better will be the performance with high-frequency (HF) transformer and passive components. Thus, the power density and operational efficiency will be higher compared to a typical hard switching converter. Considering ac input from the utility grid, a boost converter has integrated to improve power factor (PF) and lower THD. A 1 kW prototype is designed and developed that consists of a rectifier, boost converter, full-bridge inverter, HF ferrite core transformer, LC filter, and welding accessories (clamp, electrode, etc.). The effectiveness is tested under low voltage (LV) and high current (HC) situation as an arc welding machine by using both grid and photovoltaic (PV) array.

2009 1st International Conference on the Developements in Renewable Energy Technology (ICDRET), 2009

ABSTRACT Photovoltaic cell converts solar energy directly into electricity. This paper describes ... more ABSTRACT Photovoltaic cell converts solar energy directly into electricity. This paper describes a design of a charge controller to get the maximum power by using the Pulse Width Modulation (PWM) technique. In this paper PWM is controlled by the PIC Microcontroller. The work of the paper is to charge a 12 volt battery by using a 50 watt solar panel with maximum power. In this paper how maximum power can be achieved from solar panel to charge the battery through PWM signal generated by microcontroller is discussed and the experiments by taking voltage and current's values in different time interval are shown. Finally the experimental results are illustrated in this paper.

2019 International Conference on Robotics,Electrical and Signal Processing Techniques (ICREST), 2019

In this research, we have designed and developed an EOG-based Electric Wheelchair system for pati... more In this research, we have designed and developed an EOG-based Electric Wheelchair system for patients suffering from Quadriplegia or Quadriparesis or similar condition where a person is not only unable to walk but also unable to move fingers to press a button. The designed EOG recorder is used to capture intentional eye blink and eye movements (i.e. EOG signals) performed by the patient sitting in the Wheelchair. The recorded EOG signals are then processed in Arduino platform and converted to command signals to control the movement of the wheelchair in four directions (i.e. left, right, front and back) from four different EOG signals (i.e. left, right, up and down eye movements) along with start and stop commands from intentional eye blink signals. The electric wheelchair is also designed and implemented by converting a normal chair to wheelchair with necessary motors (2 DC brushed motors), wheels, and control circuitry along with the battery power supply. The EOG system is portable, wireless and user friendly which can be worn by the patient to control the wheelchair. Test experiment with subjects suggests that the proposed EOG system can detect different eye movements with an average accuracy of 90% in controlling the wheelchair. The overall cost of the developed system is around 20,000 BDT which is affordable. The proposed system has a huge potential to be used by our country’s rural and middle-income people suffering from similar disability who can’t afford commercially available expensive automated electric wheelchairs. This work can be further modified to use in other applications for the same type of patients such as EOG controlled mouse cursor for computer use. Thus this EOG-based human-machine interface applications can significantly enhance the quality of life for such middle-income or lower-middle income patients living in the developing countries such as Bangladesh.

2019 1st International Conference on Advances in Science, Engineering and Robotics Technology (ICASERT), 2019

The rapid growing battery-powered and plug-in hybrid electric vehicles will have a significant im... more The rapid growing battery-powered and plug-in hybrid electric vehicles will have a significant impact on power networks due to their zero carbon emission and mass deployment. DC motors, AC induction motors, and Brushless Direct Current (BLDC) motors are used worldwide in electric vehicles for years. Among them, BLDC motors are one of the electrical drives that are continually gaining popularity in motion control applications due to their high efficiency, good dynamic response and low maintenance. Unlike DC motors and Induction motors, BLDC motors need a controller as the motors run in 3 phase but take DC input. The controller converts DC power to 3 phase AC power suitable for the motor. This paper describes the design and development of a BLDC motor controller and its performance comparison with the existing BLDC motor controller imported from abroad. The controller circuit is simulated in Proteus software and the PCB is designed in ARES.

2021 International Conference on Science & Contemporary Technologies (ICSCT), 2021

This paper presents a high-power density onboard integrated charger with multiple outputs-based H... more This paper presents a high-power density onboard integrated charger with multiple outputs-based H-bridge converters for BMS (Battery Management System) integrated li-ion battery bank used in upgraded electric vehicles. The proposed converter can operate as AC to DC battery charger and to transfer power from the supply grid to multiple battery packs through discrete BMS of the system drivetrain. The BMS controls over voltage, overcurrent, and temperature of the battery pack. This operation will be done more efficiently with the separate power supply to these discrete BMSs. To obtain a high efficiency and high-power density, an HF tapped-transformer is used to meet the requirement of improved system size and reliability by attenuating magnetizing and copper losses with high-switching frequency operation. But the traditional H-bridge circuit suffers from switching loss due to HF operation. To solve this, zero-voltage switching (ZVS) topology was integrated. The impact of the proposed t...

2017 International Conference on Electrical, Computer and Communication Engineering (ECCE), 2017

This paper proposes the design of an efficient zero voltage switching parallel quasi resonant inv... more This paper proposes the design of an efficient zero voltage switching parallel quasi resonant inverter for small scale industrial and domestic applications using solar energy as the dc input and induction heating technology. The resonant inverter is designed using PSIM software and the designed model is verified using the PROTEUS software which operates for a frequency around 20KHz under ZVS condition for different equivalent heating workpiece resistance. The resonant frequency can be varied over a range by altering the duty cycle values. The detail design of the resonant inverter using PSIM and PROTEUS along with the simulation results of ZVS condition and data analysis are presented in this paper.

2016 IEEE International Conference on Power and Renewable Energy (ICPRE), 2016

With the improvement of technology and economic enhancement, people are now using fuel or grid po... more With the improvement of technology and economic enhancement, people are now using fuel or grid powered machine for food processing. Among all agricultural crops, rice is the main crop cultivated in Bangladesh and a high efficient processing is required for this. But excessive rise of fuel prices and limitation of power supply to the off grid areas is an obstacle for this sector. Ozone gas emissions for both fuel burning and power generation results in global warming and health issues due to inhalation of the smoke. Because of a good solar irradiation pattern, a solar powered rice husking machine can minimize this burden from the nation. The purpose of this paper is to design and analyse the performance of solar powered rice husking system. Physical demonstration was made by installing 2 kW crystalline PV modules by setting up the rice husking machine with VFD based 3-phase inverter and other measuring equipment in experimental building. Based on maximum solar irradiation, projected output is analysed by using PSIM simulation and the prospect of solar powered rice husking system in Bangladesh is shown with economic feasibility. Based on the experimental data, the performance of the system is also analysed and presented in this paper.

2020 11th International Conference on Electrical and Computer Engineering (ICECE), 2020

This paper presents multiple systems integration schemes with the solar micro-off-grid by using 3... more This paper presents multiple systems integration schemes with the solar micro-off-grid by using 3-phase variable frequency drive (VFD) inverters. The integrated system (IS) combines two crystalline photovoltaic (PV) arrays of 4.2kWp and 2.8kWp respectively. Considering small industrial applications, three distributed induction motor (IM) loads were installed i.e., two 3HP/2.2kW pumps and a 2HP/1.5kW motor. To minimize the power loss, an HV DC transmission line of350V was considered. The 3$-\varphi$ IM controllers ensure perturb and observation (P&O) maximum power point tracking (MPPT) operation to harness maximum power from the PV array. The 7kWp parallel system maintains an efficiency of over 90% from the PV array and the IGBT module based MPPT inverters keep running with an efficiency of 93%. The performance of the system is analyzed and verified using experimental data.

2020 IEEE Region 10 Symposium (TENSYMP), 2020

We consider classes of objective functions of cardinality constrained maximization problems for w... more We consider classes of objective functions of cardinality constrained maximization problems for which the greedy algorithm guarantees a constant approximation. We propose the new class of γ-α-augmentable functions and prove that it encompasses several important subclasses, such as functions of bounded submodularity ratio, α-augmentable functions, and weighted rank functions of an independence system of bounded rank quotient-as well as additional objective functions for which the greedy algorithm yields an approximation. For this general class of functions, we show a tight bound of α γ • e α e α −1 on the approximation ratio of the greedy algorithm that tightly interpolates between bounds from the literature for functions of bounded submodularity ratio and for α-augmentable functions. In particular, as a byproduct, we close a gap left in [Math.Prog., 2020] by obtaining a tight lower bound for α-augmentable functions for all α ≥ 1. For weighted rank functions of independence systems, our tight bound becomes α γ , which recovers the known bound of 1/q for independence systems of rank quotient at least q.

2020 IEEE Region 10 Symposium (TENSYMP), 2020

Irrigation is a very common term in agricultural countries like Bangladesh. For small scale culti... more Irrigation is a very common term in agricultural countries like Bangladesh. For small scale cultivation, farmers mainly use surface water for irrigation by lifting them manually or by portable diesel pump. This typical manual irrigation requires heavy labor and diesel pump requires fuels that are exhaustible and non-friendly to the environment. In this paper, the design and construction of a solar-powered portable-floating boat for small scale irrigation is showed. It will replace the typical systems with a clean, efficient and controlled performance and ensures the proper usage of surface water and make irrigation more comfortable for farmers. A pump controller is used to run a single-phase water pump which ensures maximum power point tracking (MPPT) operation to extract maximum energy from solar. 3D model of the system was developed by using Google SketchUp and the pump controller was designed and simulated by using Proteus Design Suite software. The performance and economic feasibility of the proposed system are also evaluated in this paper by comparing it with an equal capacity conventional solar irrigation system.

2016 IEEE Region 10 Conference (TENCON), 2016

This paper aims to analyse the behaviour of a parallel quasi resonant converter for a proposed so... more This paper aims to analyse the behaviour of a parallel quasi resonant converter for a proposed solar based induction cooking system under ZVS condition. The IGBT incorporated in the resonant converter will switch as a self oscillating circuit and operate under ZVS condition to minimize switching losses. The resonant converter simulation design responds to different equivalent pan resistances and it can be said that the equivalent pan resistance of 5Ω will provide the maximum efficiency of the system at a resonant frequency of 20KHz. The resonant frequency can be varied by changing the duty cycle parameter in the control part of the design for a range of 14KHz ∼ 33KHz. The output power of the cooking pan is seen to vary for different pan resistances to obtain an efficiency of the system that varies within the range of 75% ∼ 93%. The resonant converter was designed and analysed in PSIM software to show these analysis.