Saad Ul Hasan (S’09-M’19) received his B.S and M.S degrees in Electrical Engineering respectively from Bahria University, Islamabad, Pakistan, and Xi’an Jiaotong University (XJTU), Xi’an, China. From September 2011 to July 2013, he was with Power Electronics & Renewable Energy Research Center (PEREC), as a Graduate Student with XJTU. He finished his PhD in Electronics Engineering from Macquarie University, Australia in 2018 and currently working as an honorary Research Associate at University of Technology, Sydney, Australia.
During the summer of 2017, he was a visiting scholar at Miami University, Ohio, USA where worked on novel common-ground transformerless inverters for grid connected PV systems. His research interests include DC–DC and DC–AC power converters, EMI suppression in power converters, and wide bandgap (GaN/SiC) based high frequency power converters.
Mr Hasan is a frequent reviewer of APEC, ECCE, IET power electronics, JESTPE and transactions on Industrial Electronics. He is also an active IEEE member and currently serving as Mentor Chair in IEEE NSW section.
- Memeber, Institute of Electrical and Electronics Engineers (IEEE)
- Chair, IEEE student branch, Macquaire University (2016)
- Committee Member, IEEE NSW Section
Ul Hasan, S & Town, GE 2018, 'An Aperiodic Modulation Method to Mitigate Electromagnetic Interference in Impedance Source DC-DC Converters', IEEE TRANSACTIONS ON POWER ELECTRONICS, vol. 33, no. 9, pp. 7601-7608.View/Download from: UTS OPUS or Publisher's site
Chen, J, He, Y, Ul Hasan, S & Liu, J 2015, 'A Comprehensive Study on Equivalent Modulation Waveforms of the SVM Sequence for Three-Level Inverters', IEEE TRANSACTIONS ON POWER ELECTRONICS, vol. 30, no. 12, pp. 7149-7158.View/Download from: Publisher's site
Gautam, S, Yunqing, P, Kafle, Y, Kashif, M & Ul Hasan, S 2014, 'Evaluation of fundamental d-q synchronous reference frame harmonic detection method for single phase shunt active power filter', International Journal of Power Electronics and Drive Systems, vol. 4, no. 1, pp. 112-126.View/Download from: Publisher's site
Active Power Filter has become popular choice to address the harmonic pollution present in power system. It relies on fast and accurate detection of reference current to guarantee efficient compensation performance. In this paper harmonic extraction using d-q Synchronous Reference Frame (SRF) for single phase system and various aspects defining its performance is presented. The effect of the orthogonal signal generation on the harmonic current extraction is analyzed. Three different filtering approaches are compared based on their time and frequency domain characteristics. The effect of DC offset in the measured load current, introduced during measurement and data processing is derived. Accordingly a novel method to eliminate this DC offset is proposed with minimum compromise on the dynamics of the system. The discussions presented are validated using simulation results. © 2014 Institute of Advanced Engineering and Science. All rights reserved.
Hasan, SU, Shaffer, B, Hassan, HA, Scott, MJ, Siwakoti, Y & Town, GE 2018, 'Common-ground transformerless inverter for solar photovoltaic module', Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC, IEEE Applied Power Electronics Conference and Exposition, IEEE, San Antonio, TX, USA, pp. 167-172.View/Download from: UTS OPUS or Publisher's site
© 2018 IEEE. This paper presents a new single-phase transformerless inverter providing common ground for grid-connected photovoltaic (PV) systems. It consists of 5 switches, one diode, one capacitor, one small inductor and a small filter at the output stage. A simple Unipolar Sinusoidal Pulse-Width Modulation (SPWM) technique is used to operate the proposed inverter to minimize losses, output current ripple, filter requirements and improve its electromagnetic compatibility (EMC). The proposed topology shares a common ground with the grid and a capacitor is utilized as a virtual DC bus to provide the negative power cycle of the inverter. The capacitor is charged regardless of any switching cycle using a dedicated switch which can in turn reduce the size of capacitor in relation to the switching frequency. The peak ac output voltage is equal to the input DC voltage which reduces the requirement of the high input DC voltages. Simulation and experimental results for a 1 kW prototype are presented to demonstrate the usefulness of the proposed topology.
Shaffer, B, Hassan, H, Scott, M, Hasan, S, Town, GE & Siwakoti, Y 2018, 'A common-ground single-phase five-level transformerless boost inverter for photovoltaic applications', Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC, Applied Power Electronics Conference and Exposition, IEEE, San Antonio, TX, USA, pp. 368-374.View/Download from: UTS OPUS or Publisher's site
© 2018 IEEE. This paper presents a transformerless five-level boost inverter with common ground connection for single-phase photovoltaic (PV) systems. It consists of nine switches, two capacitors, and an LC filter at the output. The topology eliminates common mode (CM) leakage current by connecting the negative terminal of the PV directly to the neutral point of the grid, which bypasses the PV array's stray capacitance. As compared to the conventional flying capacitor (FC) multilevel inverter and the cascaded H-bridge (CHB) multilevel inverter, the proposed topology achieves an output voltage that is up to four-times higher given an equivalent dc-link voltage. This reduces the dc-link voltage requirement to one fourth of the values used in conventional multilevel inverters (FC, CHB, NPC, ANPC) and one half of the conventional H-bridge topologies. The following manuscript presents the operation principles and theoretical analysis of the proposed topology, which are supported by simulation and experimental results. A 1 kW prototype was constructed; it achieves 96 % efficiency operating at an output of 240 VAC, 60 Hz, and 973 W.
Hasan, SU, Kafle, YR & Town, GE 2017, 'Simple spread-spectrum pulse-modulation technique for EMI mitigation in power converters', 2017 Australasian Universities Power Engineering Conference, AUPEC 2017, Australasian Universities Power Engineering Conference, IEEE, Australia.View/Download from: UTS OPUS or Publisher's site
© 2017 IEEE. The adoption of wide-bandgap (WBG) switching devices such as gallium nitride (GaN) transistors in power converters enables to achieve higher switching frequencies and higher power density with reduced cooling requirements and smaller passive components. However, the potential for increased electromagnetic interference (EMI) resulting from the faster switching transients possible with WBG devices is a concern in many applications. Hence techniques for reducing EMI are of increasing interest. In this paper we present a simple implementation of a spread-spectrum pulse-modulation technique to reduce the peak EMI generated by switch-mode power converters. The method is based on an aperiodic gate drive signal generated from two periodic signals, e.g. a sawtooth and a sinewave, which are anharmonically related. Simulations and experimental measurements of conducted EMI from a prototype of a SEPIC converter incorporating a hybrid GaN HEMT demonstrated a 10 dB reduction in peak EMI.
Kafle, YR, Hasan, SU, Kashif, M, Hossain, J & Town, GE 2017, 'A New PWM Shoot-through Control For Voltage-Fed Quasi-Z-Source DC/DC Converters', 2017 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC), IEEE International Telecommunications Energy Conference (INTELEC), IEEE, Gold Coast, AUSTRALIA, pp. 494-497.
Kafle, YR, Ul Hasan, S & Town, GE 2017, 'A New PWM Shoot-through Control Technique to Reduce Switching Losses in Impendance Source DC/DC Converters', 2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE), 2017 9th Annual IEEE Energy Conversion Congress & Exposition (ECCE), IEEE, Cincinnati, OH, pp. 2227-2231.
Ul Hasan, S & Town, GE 2017, 'An FPGA-based Aperiodic Modulation Strategy for EMI Suppression in Quasi-Z-Source DC-DC Converters', 2017 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), IEEE International Symposium on Circuits and Systems (ISCAS), IEEE, Baltimore, MD.
Ul Hasan, S, Kafle, YR & Town, GE 2017, 'Aperiodic Pulse-Modulation Technique to Reduce Peak EMI in Impedance-Source DC-DC Converters', 2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE), 2017 9th Annual IEEE Energy Conversion Congress & Exposition (ECCE), IEEE, Cincinnati, OH, pp. 5369-5374.
Ul Hasan, S & Town, GE 2016, 'A Quasi-Periodic Modulation Strategy to Mitigate EMI for a GaN-based Quasi-Z-Source DC-DC Converter', 2016 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE), 8th Annual IEEE Energy Conversion Congress and Exposition (ECCE), IEEE, Milwaukee, WI.
Nizami, IF, Ul Hasan, S & Javed, IT 2015, 'A wavelet frames + K-means based automatic method for lung area segmentation in multiple slices of CT scan', 17th IEEE International Multi Topic Conference: Collaborative and Sustainable Development of Technologies, IEEE INMIC 2014 - Proceedings, pp. 245-248.View/Download from: Publisher's site
© 2014 IEEE. Computer assisted detection of lung nodules offers a more accurate method of nodule detection which leads to reliable diagnosis of lung cancer. Lung segmentation is a first step in the process of automatic detection of nodules. In this paper, we propose a wavelet packet frames based approach for effective lung segmentation. The proposed algorithm selects the optimal wavelet representation that is a collection of wavelet packet frames. The frames are subsequently used for clustering of coefficients using k-means clustering, which leads to the segmented lung region. The algorithm is tested on the one publicly available dataset containing 350 images and CT scan dataset of 5 local patients containing a total of 71 images. Accurate segmentation of lung is acquired with average difference in pixels from the ground truth being as low as 1.34±0.451. Furthermore, the proposed technique is fully automated and is capable of segmenting lung in multiple slices with no manual intervention or change in parameters.
Shahzad, A, Umer, M, Hasnain, SA, Ahsan, M, Hasan, M & ul Hasan, S 2015, 'Coaxial Cable Noise Removal Using Instrumentation Amplifier', 2015 34TH CHINESE CONTROL CONFERENCE (CCC), 34th Chinese Control Conference (CCC), IEEE, Hangzhou, PEOPLES R CHINA, pp. 6512-6516.
Liu, F, Liu, J, Zhang, B, Zhang, H & Ul, HS 2013, 'GENERAL IMPEDANCE/ADMITTANCE STABILITY CRITERION FOR CASCADE SYSTEM', 2013 IEEE ECCE ASIA DOWNUNDER (ECCE ASIA), 5th IEEE Annual International Energy Conversion Congress and Exhibition (ECCE) Asia DownUnder Conference, IEEE, RMIT Univ, Melbourne, AUSTRALIA, pp. 422-428.
Liu, F, Liu, J, Zhang, B, Zhang, H & Ul, HS 2013, 'Generalized Stability Criterion of Multi-module Distributed System', 2013 IEEE ECCE ASIA DOWNUNDER (ECCE ASIA), 5th IEEE Annual International Energy Conversion Congress and Exhibition (ECCE) Asia DownUnder Conference, IEEE, RMIT Univ, Melbourne, AUSTRALIA, pp. 416-421.
Liu, F, Liu, J, Zhang, B, Zhang, H, Ul, HS & Zhou, S 2013, 'Unified Stability Criterion of Bidirectional Power Flow Cascade System', 2013 TWENTY-EIGHTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2013), 28th Annual IEEE Applied Power Electronics Conference and Exposition (APEC), IEEE, Long Beach, CA, pp. 2618-2623.
Liu, F, Liu, J, Zhang, H, Xue, D, Ul, HS & Zhou, L 2013, 'Modified Norm Type Stability Criterion for Cascade AC System', 2013 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE), IEEE Energy Conversion Congress and Exposition (ECCE), IEEE, Denver, CO, pp. 442-447.
Liu, F, Liu, J, Zhang, H, Xue, D, Ul, HS & Zhou, L 2013, 'Stability Issues of Z plus Z or Y plus Y Type Cascade System', 2013 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE), IEEE Energy Conversion Congress and Exposition (ECCE), IEEE, Denver, CO, pp. 434-441.
Ul Hasan, S, Liu, J, Liu, F & Zhang, H 2013, 'Practical Design Considerations for Coupled Inductor Based Bi-directional Converters of High Voltage Ratio', 2013 IEEE INTERNATIONAL CONFERENCE OF IEEE REGION 10 (TENCON), IEEE International Conference of Region 10 (TENCON), IEEE, Xian, PEOPLES R CHINA.
Fangcheng, L, Jinjun, L, Bin, Z, Haodong, Z & Ul, HS 2012, 'Energy management of hybrid energy storage system (HESS) based on sliding mode control', Conference Proceedings - 2012 IEEE 7th International Power Electronics and Motion Control Conference - ECCE Asia, IPEMC 2012, pp. 406-410.View/Download from: Publisher's site
The renewable energy has become the research focus in recent years with the environment-friendly characteristic. Integrating energy storage system to the renewable energy system can enhance the stability and reliability of the whole power system. As one of the core technologies, energy management of the hybrid energy storage system attracts more and more attention. Hybrid energy storage system can improve the performance of the storage device with the battery as the main power source and the super capacitor as the auxiliary power source. This paper presents a control strategy based on the DC voltage regulation via sliding mode control that changes the working conditions of battery and super capacitor. When the supercapacitor voltage stays in the working range as designed, it will work as the auxiliary power source to maintain the DC voltage. When the supercapacitor voltage reaches the upper limit or the lower limit, the battery will be controlled to maintain the DC bus voltage, making the super capacitor voltage remain in a proper range. The simulation model is established in MATLAB and simulation results verify the validity of the proposed control method. © 2012 IEEE.