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Full-Text Articles in Engineering
An Islanding Detection Strategy For Distribution Network Connected With Hybrid Dg Resources
An Islanding Detection Strategy For Distribution Network Connected With Hybrid Dg Resources
Faculty of Engineering University of Malaya
The exponential growth in electricity demand has driven the Distributed Generation (DG) technology a boost in the power system. The use of DG is beneficial to power utilities, DG owners', and end-users in terms of reliability, power quality, and economics. However, to fully utilize the benefits of DGs, some technical issues need to be addressed. Islanding condition is one of the most important issue in this context. Until now, several islanding detection techniques have been proposed for detecting the islanding condition. This paper presents a brief overview of existing islanding detection techniques with their relative merits and demerits. Apart from …
A New Low-Profile Inverted A-Shaped Patch Antenna For Multi-Band Operations
A New Low-Profile Inverted A-Shaped Patch Antenna For Multi-Band Operations
Faculty of Engineering University of Malaya
This paper presents the design and analysis of a compact modified inverted-A shape multi-band patch antenna for WiMAX and C-band telecommunication satellite applications. The proposed antenna has simple geometrical structure which consist of 20 mm x 20 mm radiating patch with slot loading and fed by 4 mm long microstrip line. The proposed antenna is designed and analyzed by using commercially available full-wave 3D high frequency electromagnetic simulator namely Ansys HFSS. The optimized design of the proposed multi-band patch antenna is fabricated on 1.6 mm thick fiberglass polymer resin dielectric material substrate with reduced ground plane by using in-house PCB …
Zigbee-Based Data Acquisition System For Online Monitoring Of Grid-Connected Photovoltaic System
Zigbee-Based Data Acquisition System For Online Monitoring Of Grid-Connected Photovoltaic System
Faculty of Engineering University of Malaya
For grid-connected photovoltaic (PV) system, monitoring is considered as a crucial aspect for observing the stability and performance of the system. The simplest method is to have the data collected and transmitted across data cables. Due to the cost and technical limitations of the data cable, the monitoring station needs to be located reasonably close to the monitored plant. Apart being inconvenient, the use of data cable often adds capital and maintenance cost to the system. In this research project, a Zigbee-based wireless monitoring system is developed for online monitoring of a grid-connected photovoltaic system. Parameters like temperature, irradiation, PV …
Development Of Novel Passive Check Valves For The Microfluidic Cd Platform
Development Of Novel Passive Check Valves For The Microfluidic Cd Platform
Faculty of Engineering University of Malaya
Microfluidic CD platforms are utilized to perform different biological processes and chemical analyses. In general, a microfluidic CD implements the centrifugal force that is created by the spinning of the platform to pump liquid through the microfluidic network of chambers and channels. Over the last few decades, a wide range of active and passive valving methods were proposed and tested on various microfluidic platforms. Most of the presented valves are too complex to design and involve lengthy fabrication processes. In this paper, easy to fabricate air and liquid check valves for centrifugal microfluidic platforms are presented: a Terminal Check Valve …
Effective Utilization Of Excess Energy In Standalone Hybrid Renewable Energy Systems For Improving Comfort Ability And Reducing Cost Of Energy: A Review And Analysis
Faculty of Engineering University of Malaya
One of the features that characterize renewable energy sources is their variability and intermittency. Intermittency covers both the predictable and unpredictable variations of their power outputs and uncertainty in the power availability. To overcome the drawback of intermittency, special design considerations should be taken into account. These additional design considerations increases the overall cost of the renewable energy systems. Adding storage system and/or backup source to the renewable sources is one of the measures used to guarantee the continuity of power supply to the loads, and therefore improve the reliability of the renewable energy systems. The operation of renewable energy …
Fuzzy Swinging-Up With Sliding Mode Control For Third Order Cart-Inverted Pendulum System
Fuzzy Swinging-Up With Sliding Mode Control For Third Order Cart-Inverted Pendulum System
Faculty of Engineering University of Malaya
Cart Inverted Pendulum (CIP) system is a benchmark problem in nonlinear automatic control. In this paper, two third-order differential equations were derived to create a combining model for the cart-pendulum with its DC motor dynamics. Motor voltage was considered the system input in the presented model. The friction between the cart and rail was included in the system equations through a nonlinear friction model. Fuzzy Swinging-up controller was designed to swing the pendulum to the upright position, once reaching the upward position; Sliding Mode Controller (SMC) is activated, to balance the system. In order to verify the performance of the …
Semi-Z-Source Inverter Topology For Grid-Connected Photovoltaic System
Semi-Z-Source Inverter Topology For Grid-Connected Photovoltaic System
Faculty of Engineering University of Malaya
Transformer-less inverters are necessary parts for grid-connected renewable energy resources. Owing to its cost effectiveness, downsize and less weight, great attention has been paid to these inverters development. With these aforementioned advantages, these inverters have limitations like the flow of leakage current through photovoltaic arrays, high total harmonic distortion (THD) at inverter's output and DC current injection to the grid. This study presents coupled inductor-based single-phase transformer-less semi-Z-source inverter topology to lessen those limitations. Since the DC input and AC output voltage share a common ground, the presented inverter system is categorised under doubly grounded topologies. For the purpose of …