Liew Hui Fang
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Preferred name
Liew Hui Fang
Official Name
Hui Fang, Liew
Alternative Name
Fang, Liew Hui
Liew, Hui Fang
Liew, H. F.
Fang, L. H.
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Scopus Author ID
55987930400
Researcher ID
AAF-4915-2021

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Numerical analysis of comparison highly efficient active rectifier for energy harvesting application

2023-08 , Liew Hui Fang , Diyya Hidayah Abd Rahman , Muhammad Izuan Fahmi Romli , Mohd Arif Mohd Zain , Junaidah Ali Mohd Jobran , Norhanisa Kimpol

A piezoelectric energy harvesting (PEH) circuit with a passive rectifier lack in efficiency and performance. The performance and potential of piezoelectric energy-harvesting devices depend strongly on the power conditioning circuit as the circuits are essential for managing and controlling energy flows in these energy collecting devices. In order to overcome this situation, the parallel synchronized switch harvesting on inductor (P-SSHI) and the general model of synchronized multiple bias-flip (SMBF) which are the recent implementation of parallel synchronized triple bias-flip (P-S3BF) and parallel synchronized septuple bias-flip (P-S7BF) are used for further enhancing the PEH performance. In addition, active rectifiers presented distinguished benefits over passive rectifiers, such as the ability to analyze regulation, dynamic response to load changes, output voltage ripple, input current, total harmonic distortion (THD), power factor correction, and wave factor. Furthermore, by using an active rectifier the output voltage can be boosted higher. Thus, it is more efficient than a lower voltage since it experiences less energy loss from resistance. This research investigates the several high efficiency AC-DC active rectifiers as interface circuit plays a crucial role in the energy harvesting capability enhancement in PEH systems. The research methodology is carried out on a piezoelectric structure under the same base circuit with a different type of power conditioning circuit applied to the main circuit using the LTspice software. In conclusion, the input voltage for each different active rectifier circuit were set at 3-5 V and the frequency is set based on the input voltage of the circuit. Based on the results, the P-S7BF shows the higher efficiency with voltage output will have the most efficiency with the estimated voltage output reaching up to 13 V with a net harvesting power of up to 80-90% follow up by the P-S3BF and P-SSHI. There are several recommendations to improve active circuit by investigation the impact of load variation on the efficiency, such as different loads may require different rectification techniques and control strategies to achieve high efficiency.

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Piezoelectric Array Configuration Technique into Enhance Power Catchment for Sound Energy Harvester System

2020-11-18 , Liew Hui Fang , Rosemizi Abd Rahim , Muhammad Izuan Fahmi Romli , Mohamad Zhafran Zakariya , Junaidah Ali Mohd Jobran , Norhanisa Kimpol

The objective of this study is to explore the harvest maximum output changes occurs in piezoelectric transducer when connected in different configuration to produce highest electricity consumption and generate sound energy harvesting system. Acoustic energy is a type of environmental energy source that can be extracted and converted into electrical energy for small-scale energy applications. In this study, the corresponding load resistance for single piezoelectric transducer is 4.5 k$\Omega$, together with a constant vibration source at a frequency of 68 Hz and a 1-g acceleration. The performance of output voltage and power of piezoelectric are evaluated and the optimum output is measured by depending on the connection of the piezoelectric transducer arrangement into series, parallel and series, and parallel which stimulated using Proteus software. The experiment result presented that, when have single piezo, 5 piezo connected in series, and 5 piezo connected in parallel, the output powers are 1.664 mW, 1.671mW and 7.676 mW, respectively. During the combination series and parallel connections, the output power of 3S1P piezo increases to 5.05mW. In a parallel configuration, the output voltage that produced is much higher than a piezoelectric transducer arrangement connected in series connection. The piezoelectric transducer that connected in parallel configurations increases its voltage output from 2.83 V to 13.05 V with the same polarity. The arrangement of piezoelectric transducer in parallel configuration is affordable, with its higher production of a higher power output compared to the arrangement of piezoelectric transducer in series connection. Whereas in terms of power output, the maximum power remains constant in the range of 1.665 to 1.671 mW when three transducers are in series configuration connection with the same polarity. In conclusion, the proper implementation of the piezoelectric array configuration is needed in order to operate the minimum energy for low load devices and promise to accomplish generated optimum power output in harvester system.

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Environmental noise harvester for low voltage power supply

2018 , Liew Hui Fang

There is an increased awareness nowadays regarding the potential shortage of fuel sources for electricity generation in the future, where various studies have been conducted about the usage alternative sources. Currently, the renewable energy has been prioritized for instance, through ambient energy scavenging. To achieve this goal, sound, being the most abundant energy in the environment, is likely the best candidate to fill the slot. The existing rectifying technique that has been used for energy transfer in energy harvesting is ‘switch-only’ and ‘bias-flip’ techniques which is utilize an additional switches or switched inductors for speedy voltage rectification. However, such techniques depend on the timing accuracy and synchronization of the pulses of the switch whenever the changes in the currents' polarity generated by the piezoelectric harvester. The existing acoustics-based energy harvesting systems utilized a self powered active rectifying diode circuitry technique to converts alternating current signal to direct current. The active MOSFET rectifier circuit has extra components and required an external DC supply to powering the rectifying circuit. Thus it is not a good option for small scale harvester system and suffered some drawbacks in the implementation of the circuit. Although synchronous switch harvesting on the inductor(SSHI) and synchronous electric charge extraction (SECE) rectifiers possess high efficiency to extract and harvest the energy available from system, they have drawbacksof SSHI circuits such as the complexity of the circuit which is can contribute to additional losses of power, threshold voltages, frequency selectivity and parasitic bandwidth filters. In this study, the developments of passive circuit including voltage multipliers (Dickson and Villard circuits) and step-up transformer were proposed and designed to rectify the low voltage acoustic voltage. The simulation of the proposed harvesting circuit was performed using Multisim and Portus simulator. For verification purpose, the PZT-5A piezoelectric transducer model has been chosen as the harvester due to the consistency. During the experiment, the resonance frequency of the harvestersystem was at 68 Hz with the 95 dB of acoustic pressure. The experimental results showed that the output closed-circuit voltage and the output power harvester can reach up to 3.894Vrmsand 1.556mW respectively. The passive AC-DC harvesting circuits can probably achieve the overall energy conversion efficiency by 78.9% (Dickson circuit) (1.228mW), 70.5% (Villard circuit) (1.097mW), and 10.1% (step-up transformer) (0.1564mW) respectively. Based on the results presented above, the proposed energy harvesting systems seem to be promising and possess a good potential to be used in low power sensors such as wireless sensor networks.

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