Javed Ahmad

Mr. Javed Ahmad

National Taiwan University of Science and Technology, Department of Electrical Engineering
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 February 2024 in IEEE Access
Verified
Journal Article
Open access
Chang-Hua LinChang-Hua Lin
Chang-Hua Lin
MKMohammad Suhail Khan
Mohammad Suhail Khan
Javed AhmadJaved Ahmad
Javed Ahmad
Hwa Dong LiuHwa Dong Liu
Hwa Dong Liu
THTung-Chun Hsiao
Tung-Chun Hsiao
High-gain DC-DC converters are becoming increasingly popular in renewable energy applications and solar PV systems. This article introduces a non-isolated non-coupled inductor-based high-gain DC-DC boost converter with the desirable features of low voltage stress on controlled power switches and high voltage gain at lower duty ratios. The proposed converter is well suited for boosting the low-input DC voltage obtained from distributed generation units like photovoltaic (PV) or fuel cells to substantially higher DC voltage. The converter comprises only two switches, and a single PWM signal governs its operation. These characteristics result in a topology that is more compact, less costly, lighter weight, and easier to control. The proposed converter is compared with some previously developed topologies of high-gain boost converters across various performance parameters. This comparison illustrates that the proposed model surpasses them in every aspect. A 300 W hardware prototype of a proposed model is developed and tested in a laboratory environment to confirm the theoretical assertions of a proposed model. The proposed topology offers a promising solution and enables a high gain of approximately 12 times the input voltage at a smaller duty ratio, specifically 11.25 at a duty of 0.6 and 17.77 at a duty of 0.7. The efficiency of a proposed converter ranges between 92.5% to 94.5% making it appropriate for numerous medium-high power applications. The uniqueness of the suggested system is its simple design and greater efficiency, which provides a more considerable gain and higher output voltages for sustainable energy systems.

6 September 2021 in IEEE Access
Verified
Journal Article
Open access
SKShahrukh Khan
Shahrukh Khan
MZMohammad Zaid
Mohammad Zaid
AMArshad Mahmood
Arshad Mahmood
ANAbbas Syed Nooruddin
Abbas Syed Nooruddin
Javed AhmadJaved Ahmad
Javed Ahmad
CLChang-Hua Lin
Chang-Hua Lin
High gain dc-dc converters are used in several applications which include solar photovoltaic system, switch-mode power supplies and fuel cells. In this paper, an ultra-high gain dc-dc boost converter is proposed and analyzed in detail. The converter has a gain of six times as compared with the boost converter. The high gain is achieved by utilizing switched inductors and switched capacitors. A modified voltage multiplier cell (VMC) with switched inductors is proposed. The converter has a single switch which makes its operation easy. Moreover, the voltage across the switch, diodes and capacitors are less than the output voltage which increases the overall efficiency of the converter. The converter performance in steady-state is analyzed in detail and it is compared with other latest high gain converters. The working of the converter in non-ideal conditions is also discussed in detail. The loss analysis is done using PLECS software by incorporating the real models of switches and diodes from the datasheet. To confirm and validate the working of the proposed converter a hardware prototype of 200 W is developed in the laboratory. The converter achieves high gain at low duty ratios and its performance is found to be good in open and closed loop conditions.

2 April 2021 in IEEE Access
Verified
Journal Article
Open access
AMArshad Mahmood
Arshad Mahmood
MZMohammad Zaid
Mohammad Zaid
Javed AhmadJaved Ahmad
Javed Ahmad
MKMohd Anas Khan
Mohd Anas Khan
SKShahrukh Khan
Shahrukh Khan
BABasem Alamri
Basem Alamri
High gain DC-DC converters are increasingly being used in solar PV and other renewable generation systems. Satisfactory steady-state and dynamic performance, along with higher efficiency, is a pre-requirement for selecting the converter for these applications. In this paper, a non-inverting high gain DC-DC boost converter has been proposed. The proposed converter has only one switch with continuous input current and reduced voltage stress across switching devices. The operating range of the duty cycle is wider, and it obtains a higher gain at a lower value of the duty cycle. Moreover, the converter has higher efficiency at a lower duty cycle while drawing a continuous input current. The continuous input current is a desirable feature of the dc-dc converter making it suitable for solar photovoltaic applications. The converter's operation has been discussed in detail and extended to include the real circuit parameters for a practical performance evaluation. The proposed converter has been compared with other similar recently proposed converters on various performance parameters. The loss analysis for the proposed converter has also been carried out. Finally, the simulation has been validated with results from the experimental prototype.

4 May 2021 in Energies
Verified
Journal Article
Open access
PDF file
Javed AhmadJaved Ahmad
Javed Ahmad
MZMohammad Zaid
Mohammad Zaid
ADIL SARWARADIL SARWAR
ADIL SARWAR
Chang-Hua LinChang-Hua Lin
Chang-Hua Lin
MAMohammed Asim
Mohammed Asim
BABasem Alamri
Basem Alamri
The growth of renewable energy in the last two decades has led to the development of new power electronic converters. The DC microgrid can operate in standalone mode, or it can be grid-connected. A DC microgrid consists of various distributed generation (DG) units like solar PV arrays, fuel cells, ultracapacitors, and microturbines. The DC-DC converter plays an important role in boosting the output voltage in DC microgrids. DC-DC converters are needed to boost the output voltage so that a common voltage from different sources is available at the DC link. A conventional boost converter (CBC) suffers from the problem of limited voltage gain, and the stress across the switch is usually equal to the output voltage. The output from DG sources is low and requires high-gain boost converters to enhance the output voltage. In this paper, a new high-gain DC-DC converter with quadratic voltage gain and reduced voltage stress across switching devices was proposed. The proposed converter was an improvement over the CBC and quadratic boost converter (QBC). The converter utilized only two switched inductors, two capacitors, and two switches to achieve the gain. The converter was compared with other recently developed topologies in terms of stress, the number of passive components, and voltage stress across switching devices. The loss analysis also was done using the Piecewise Linear Electrical Circuit Simulation (PLCES). The experimental and theoretical analyses closely agreed with each other.

7 September 2021 in International Journal of Circuit Theory and Applications
Verified
Journal Article
Closed access
PDF file
Javed AhmadJaved Ahmad
Javed Ahmad
Marif Daula SiddiqueMarif Daula Siddique
Marif Daula Siddique
ADIL SARWARADIL SARWAR
ADIL SARWAR
CLChang Hua Lin
Chang Hua Lin
AIAtif Iqbal
Atif Iqbal

25 March 2021 in International Transactions on Electrical Energy Systems
Verified
Journal Article
Closed access
PDF file
MZMohammad Zaid
Mohammad Zaid
SKShahrukh Khan
Shahrukh Khan
Marif Daula SiddiqueMarif Daula Siddique
Marif Daula Siddique
ADIL SARWARADIL SARWAR
ADIL SARWAR
Javed AhmadJaved Ahmad
Javed Ahmad
AIAtif Iqbal
Atif Iqbal