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A SiC MOSFET Based High Efficiency Interleaved Boost Converter for More Electric Aircraft
Zaman, Haider,Zheng, Xiancheng,Yang, Mengxin,Ali, Husan,Wu, Xiaohua The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1
Silicon Carbide (SiC) MOSFET belongs to the family of wide-band gap devices with inherit property of low switching and conduction losses. The stable operation of SiC MOSFET at higher operating temperatures has invoked the interest of researchers in terms of its application to high power density (HPD) power converters. This paper presents a performance study of SiC MOSFET based two-phase interleaved boost converter (IBC) for regulation of avionics bus voltage in more electric aircraft (MEA). A 450W HPD, IBC has been developed for study, which delivers 28V output voltage when supplied by 24V battery. A gate driver design for SiC MOSFET is presented which ensures the operation of converter at 250kHz switching frequency, reduces the miller current and gate signal ringing. The peak current mode control (PCMC) has been employed for load voltage regulation. The efficiency of SiC MOSFET based IBC converter is compared against Si counterpart. Experimentally obtained efficiency results are presented to show that SiC MOSFET is the device of choice under a heavy load and high switching frequency operation.
A SiC MOSFET Based High Efficiency Interleaved Boost Converter for More Electric Aircraft
Haider Zaman,Xiancheng Zheng,Mengxin Yang,Husan Ali,Xiaohua Wu 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1
Silicon Carbide (SiC) MOSFET belongs to the family of wide-band gap devices with inherit property of low switching and conduction losses. The stable operation of SiC MOSFET at higher operating temperatures has invoked the interest of researchers in terms of its application to high power density (HPD) power converters. This paper presents a performance study of SiC MOSFET based two-phase interleaved boost converter (IBC) for regulation of avionics bus voltage in more electric aircraft (MEA). A 450W HPD, IBC has been developed for study, which delivers 28V output voltage when supplied by 24V battery. A gate driver design for SiC MOSFET is presented which ensures the operation of converter at 250kHz switching frequency, reduces the miller current and gate signal ringing. The peak current mode control (PCMC) has been employed for load voltage regulation. The efficiency of SiC MOSFET based IBC converter is compared against Si counterpart. Experimentally obtained efficiency results are presented to show that SiC MOSFET is the device of choice under a heavy load and high switching frequency operation.
Protection Coordination Using Superconducting Fault Current Limiters in Microgrids
Raza Haider,Muhammad Saeed Uz Zaman,Syed Basit Ali Bukhari,Zahoor Ahmed,Muhammad Mehdi,Yun-Sik Oh,Chul-Hwan Kim 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.10
Power generating units in the form of distributed generation (DG) are integrating with microgrid (MG) systems to supply reliable power to users. The trend of an integrated power supply is increasing continually to meet growing energy demands. Besides certain advantages of the MG system, some interconnection and system protection issues pose a challenge in terms of implementation. These problems need to be addressed in order to facilitate smooth operation of power systems. Superconducting fault current limiters (SFCLs) provide the best performance and unique protection features to electrical power systems during various fault conditions. This paper describes modeling, characterization, and implementation of SFCL in an MG system to enhance protection coordination. The proposed SFCL is modeled in MATLAB/ Simulink software and the performance of the system is validated through simulation results. It is also shown that the proposed SFCL provides a means of better relay coordination during various fault conditions. This is achieved by incorporating well-calculated design parameters of SFCL and its placement at optimal locations.
COVID-19 Vaccine: Critical Questions with Complicated Answers
( Mohammad Faisal Haidere ),( Zubair Ahmed Ratan ),( Senjuti Nowroz ),( Sojib Bin Zaman ),( You-jung Jung ),( Hassan Hosseinzadeh ),( Jae Youl Cho ) 한국응용약물학회 2021 Biomolecules & Therapeutics(구 응용약물학회지) Vol.29 No.1
COVID-19 has caused extensive human casualties with significant economic impacts around the globe, and has imposed new challenges on health systems worldwide. Over the past decade, SARS, Ebola, and Zika also led to significant concerns among the scientific community. Interestingly, the SARS and Zika epidemics ended before vaccine development; however, the scholarly community and the pharmaceutical companies responded very quickly at that time. Similarly, when the genetic sequence of SARSCoV- 2 was revealed, global vaccine companies and scientists have stepped forward to develop a vaccine, triggering a race toward vaccine development that the whole world is relying on. Similarly, an effective and safe vaccine could play a pivotal role in eradicating COVID-19. However, few important questions regarding SARS-CoV-2 vaccine development are explored in this review.
An interval type-2 fuzzy logic based strategy for microgrid protection
Bukhari, Syed Basit Ali,Haider, Raza,Saeed Uz Zaman, Muhammad,Oh, Yun-Sik,Cho, Gyu-Jung,Kim, Chul-Hwan IPC Science and Technology Press 2018 International journal of electrical power energy s Vol.98 No.-
<P><B>Abstract</B></P> <P>The concept of microgrids has been introduced to facilitate the integration of the distributed energy resources (DERs) into distribution networks in a more economical, reliable and environment-friendly manner. One of the critical challenges associated with microgrids is devising an appropriate protection strategy. This is because the fault current level continuously varies owing to the existence of DERs and to the fact that the microgrid can operate in grid-tied and islanded modes. This paper proposes a new protection strategy for microgrids using an interval type-2 fuzzy logic system. The proposed strategy considers various uncertainties associated with faults and employs two different fuzzy systems to detect, classify, and locate the faults in microgrids. The phase angle between superimposed modal voltage and modal current is used as an input to the fuzzy system designed to identify the fault direction. The significant feature of the proposed strategy is that it can protect the microgrid after a single-phase tripping event. To validate the effectiveness of the proposed strategy, we have performed extensive simulations using MATLAB/SIMULINK. The simulation results show that the proposed strategy can detect, classify, and isolate various faults in the microgrid. Moreover, the strategy also provides backup protection in case of failure of the primary protection.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Develop a new microgrid protection strategy based on interval type-2 fuzzy logic system. </LI> <LI> Considers various uncertainties associated with faults in microgrids. </LI> <LI> Identify fault direction using phase angle between superimposed modal voltage and modal current. </LI> <LI> Capable to protect the microgrid after a single-phase tripping event. </LI> </UL> </P>
Frequency Profile Improvement of a Microgrid under Abnormal Conditions via a Demand Response Program
Muhammad Saeed uz Zaman,Raza Haider,Syed Basit Ali Bukhari,Yun-Sik Oh,Min-Sung Kim,Muhammad Mehdi,Chul-Hwan Kim 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.10
The frequency deviation of an electric power system from its nominal range is a significant indicator of the system’s instability. This issue is further highlighted when the system is incorporated with intermittent renewable energy resources. In this work, the frequency regulation of a microgrid is achieved by a demand response program. The proposed plan is implemented in a central controller that has two control sections. The frequency deviation is controlled by manipulating responsive loads. In the case of higher frequency deviation, the command of the first control section is proportional to the magnitude of frequency deviation and a large amount of responsive loads is manipulated to restore the frequency to its nominal range quickly. The other section of the central controller addresses minor frequency deviations. The proposed plan is implemented on a test system and outperforms the conventional methods in terms of frequency restoration. The improvement in voltage profile is also observed during abnormal conditions after the proposed plan is implemented.
Reduced Order Identification and Stability Analysis of DC-DC Converters
Husan Ali,Xiancheng Zheng,Xiaohua Wu,Haider Zaman,Shahbaz Khan 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2
This paper discusses the measurement of frequency response functions for various dc-dc converters. The frequency domain identification procedure is applied to the measured frequency responses. The identified transfer functions are primarily used in developing behavioral models for dc-dc converters. Distributed power systems are based upon such converters in cascade, parallel and several other configurations. The system level analysis of a complete system becomes complex when the identified transfer functions are of high order. Therefore, a certain technique needs to be applied for order reduction of the identified transfer functions. During the process of order reduction, it has to be ensured that the system retains the dynamics of the full order system. The technique used here is based on the Hankel singular values of a system. A systematic procedure is given to retain the maximum energy states for the reduced order model. A dynamic analysis is performed for behavioral models based on full and reduced order frequency responses. The close agreement of results validates the effectiveness of the model order reduction. Stability is the key design objective for any system designer. Therefore, the measured frequency responses at the interface of the source and load are also used to predict stability of the system.
Reduced Order Identification and Stability Analysis of DC-DC Converters
Ali, Husan,Zheng, Xiancheng,Wu, Xiaohua,Zaman, Haider,Khan, Shahbaz The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2
This paper discusses the measurement of frequency response functions for various dc-dc converters. The frequency domain identification procedure is applied to the measured frequency responses. The identified transfer functions are primarily used in developing behavioral models for dc-dc converters. Distributed power systems are based upon such converters in cascade, parallel and several other configurations. The system level analysis of a complete system becomes complex when the identified transfer functions are of high order. Therefore, a certain technique needs to be applied for order reduction of the identified transfer functions. During the process of order reduction, it has to be ensured that the system retains the dynamics of the full order system. The technique used here is based on the Hankel singular values of a system. A systematic procedure is given to retain the maximum energy states for the reduced order model. A dynamic analysis is performed for behavioral models based on full and reduced order frequency responses. The close agreement of results validates the effectiveness of the model order reduction. Stability is the key design objective for any system designer. Therefore, the measured frequency responses at the interface of the source and load are also used to predict stability of the system.