An Enhanced Zero Crossing Based HVAC Phase Synchronous Inverter for Electrostatic Generator in Microgrid Systems

Electrostatic Generator (ESG) faced far more challenges when it integrated with the phase synchronous inverter systems as ESG can generate high voltage DC and very low current. This high DC voltage needs to be converted and also low current of the ESG have to be increased for microgrid system which works generally performed by power inverter circuit. Therefore, phase synchronous inverter (PSI) is presented, to increase the inverter output current, with the aid of zero crossing voltage source controller. However, there is an issue to design the inverter which are harmonic distortion and phase angle. In this paper, a zero-crossing circuit is developed to synchronize inverter and microgrid phase and according to the simulation result, the phase angle is 3.22°. In addition, an LCL filter is designed to reduce the harmonic distortion. The performance of the PSI had been demonstrated by modeling it in MATLAB2016a software. The considered parameter of the design is input voltage 10kV, switching frequency 60Hz, modulation index 0.85 and cut-off frequency 33Hz. The simulation results show that the designed inverter can greatly improve the system stability and robustness of the microgrid system and the obtained PSI system efficiency is 97.35% that performed better compared to the related inverter techniques

Kompaktna širokopojasna patch antena za ultra visoki frekvencijski RFID tag

A compact and simple patch antenna for ultra high frequency band is current demand for RFID tag. By embedding a pair of symmetrical key-shaped slot near the non-radiating edge of the rectangular patch, a new adjacent resonant mode close to the fundamental mode is excited to form a wide half-power impedance bandwidth (Return loss ≥ dB) of 122 MHz to cover the entire frequency range of ultra high frequency RFID operation (860-960 MHz). The structure of the antenna is completely planar without any cross or multi-layered construction thus it provides ease of fabrication and reduced cost. Performance of the antenna is evaluated by using a commercial electromagnetic simulator, Ansoft HFSS v13. Simulation results demonstrate that the antenna is able to perform considerably well when mounted on different size of metallic plate as well as in free space.Kompaktna i jednostavna patch antena za ultra visoki frekvencijski pojas potrebna je za RFID tag. Ugrađivanjem para simetričnih priključaka u blizini kuta pravokutne antene, koji nije izložen radijaciji, pobuđen je novi rezonantni mod u blizini fundamentalnog moda kako bi se formirao širok pojas od pola snage od 122 MHz koji pokriva cijeli visokofrekvencijski pojas RFID tehnologije (860-960 MHz). Struktura antene je potpuno planarna bez križanja i slojeva te je kao takva jednostavna za proizvodnju i smanjenog troška. Svojstva antene procijenjena su korištenjem komercijalnog elektromagnetskog simulatora, Ansoft HFSS v13. Simulacijski rezultati pokazuju dobre značajke antene kada je montirana na metalne ploče različitih dimenzjia ili kada je samostalna

BRIDGE SCOUR MONITORING BY COUPLING FACTOR BETWEEN READER AND TAG ANTENNAS OF RFID SYSTEM

ABSTRACT: Bridge scour is an erosion which removes stream bed or bank material from bridge foundation due to flowing of water. Too much bridge scour is risky for the bridge foundation and causes sudden bridge to collapse without any warning. It implements significant impacts on the traveling public safety as well as the economy of the country. A number of parameters are associated with scour, thus different types of sensors are required to measure the individual affecting factor. A complex and expensive data logging from sensor and electronic communication systems are used to monitor the bridge scour in real-time to ensure the integrity of bridge structure. A high frequency band (13.56MHz) radio frequency identification (RFID) system has been proposed and that has been validated by simulation using PSpice software for the direct scour monitoring scheme, which is simple and low-cost. A number of passive RFID tags have been piled surrounding the bridge foundation which is continuously detected by the FRID reader. The erosion of the river bed carries out the RFID tag from nearby the bridge structure. As a result, the RFID reader can directly detect the absence of the tags as well as the amount of the scouring. Since, the design structure of the RFID system is simple, it is highly robust and easy to implement. The system can easily be implemented with an existing bridge structure and a wireless telemetry can be used to send the real-time data from the proposed system to a desktop computer in the monitoring lab

Design and implementation of a series switching SPSI for PV cell to use in carrier based grid synchronous system

A carrier-based grid synchronous method is proposed to develop the system efficiency, phase and power quality of the inverter output waves. The operating principle of a single-phase phase synchronous inverter (SPSI) is introduced, with proper synchronous paid to the switching-frequency synchronizing voltage made by the interleaved process, as well as actual mitigation approaches. In the construction of the SPSI, input and output filters are electrically coupled with the two sides of an inverter. The inverter power electronic switches and other electrical components are operated by carrier-based grid synchronous controller (CBGSC) with PWM regulator. The SPSI is designed and implemented with the Toshiba 40WR21 IGBT, Digital Microcontroller pulse controller (DMPC) and 4N35 Optocoupler with a fundamental frequency of 50Hz. The other parameters are considered as load resistance, =11Ω, duty cycle, 85%, carrier frequency, 2.5kHz and input DC voltage, ± 340V. In addition, LCL lowpass grid filters are used to convert squire wave to sine wave with required phase and frequency. Finally, the simulated and experimental results obtained with a carrier-based grid synchronous SPSI experimental prototype are exposed for justification, showing the phase error of 55% improvement, reduced 11% of THD and the conversion efficiency of 97.02% highly predicted by the proposed design technique to improve the microgrid system

Feature Extraction of EEG Signal by Power Spectral Density for Motor Imagery Based BCI

Signals produced from the brain are widely known as Electroencephalogram (EEG) signal interfacing with any communication device creates a unidirectional communicating channel in the absence of neuro-muscular pathways. An effective Brain-Computer Interface (BCI) system basically consists of three operations which are signal recording, feature extraction and classification. Efficient and reliable classification of EEG signal for motor imagery (MI) based BCI system depends on the accuracy of denoising and extracted features of the signal. Extracted features are intended to be lossless key information obtained from a signal that describes a dataset accurately. It is important to minimize the classification complexity and maximize the accuracy. Traditional strategies can be used to process the signal, but the diverseness of the EEG signal conceivably could not be depicted utilizing a linear analytical approach. Hence, this paper adopted the power spectral density (PSD) feature extraction technique to extract the features based on various frequency transformations that enhance the classification performance. Graz BCI competition IV, dataset 2b has been utilized in this paper that consisting of two different classes of motor imagery left-hand and right-hand movement. Overall, 0.61 of Cohen’s Kappa accuracy obtained using the LDA classifier

A series regeneration converter technique for voltage balancing of energy storage devices

A single series resonant converter has been designed to balance the voltage level of a storage battery for electric vehicles. The proposed design has been simulated and verified by using two 100F supercapacitors instate of the conventional rechargeable battery. A voltage monitoring circuit detects the voltage condition of the individual capacitor and sends the voltage status to the control circuit for action. A technique has been developed to control a set of switches to transfer the current between the capacitor to balance the voltage level. The MATLAB simulated result shows the balancing circuit decreases the voltage difference between the two supercapacitors from 200 mV to 0V in 140 seconds, which is less than the existing methods. This fast voltage balancing technique can be used in the battery management system or electric vehicles for long lasting the battery life

PLL-BASED 3? INVERTER CIRCUIT FOR MICROGRID SYSTEM OPERATED BY ELECTROSTATIC GENERATOR

A current source control based PLL (phase lock loop) technique is one of the most efficient methods for modern 3? synchronized grid power systems. When an inverter circuit is driven by an electrostatic generator with wind power, it encounters some problems, such as static and dynamic turn-on-off switching losses, unbalanced source voltage, low continuous current, higher frequency harmonic distortion, phase angle imbalance, etc. To solve these problems, a series of connected switching inverter modules technique is proposed. It is not only a traditional inverter system, but it also works as a low-frequency ripple current inverter with lower switch losses. A new topology of phase synchronous inverter (PSI) is designed using a PLL current source controller. The input voltage source of the PSI is a high DC voltage from an electrostatic generator (ESG). The modified ESG is capable of generating the HVDC and a continuous moderate amount of current. The proposed switching topology of the inverter is able to control the microgrid power as well as reduce the dynamic and static switching loss. It also reduces the high-frequency harmonic distortion and improves the phase angle error. The output LCL lowpass filter scheme of the inverter is designed to reduce the total harmonic distortion of 1.62%. The PSI circuit is designed and simulated using MATLAB software. In the developed system, the input voltage of 8 k , microgrid frequency of 50Hz, switching frequency of the carrier of 10 kHz, and modulation index of 0.85 are considered to be implemented. The proposed novel microgrid connected PSI switching module design technique has significantly enhanced the power stability. The overall system efficiency improved by 95.52%. ABSTRAK: Sumber-arus terkawal berdasarkan teknik PLL (fasa litar kunci) adalah satu kaedah cekap bagi sistem moden tenaga grid selaras 3?. Apabila litar songsang (inverter) digerak menggunakan penjana elektrostatik bersama tenaga angin, ia mengalami masalah seperti kehilangan tenaga statik dan dinamik suis hidup-mati, sumber voltan yang tidak seimbang, kurang arus terus, gangguan harmoni frekuensi tinggi, ketidak-seimbangan sudut fasa, dan sebagainya. Bagi menyelesaikan masalah ini, teknik modul suis bersiri dihubung bersama inverter telah dicadangkan. Ini bukan semata-mata teknik lama sistem inverter, tetapi ia juga berfungsi sebagai arus tidak tetap frekuensi-rendah dengan kurang kehilangan tenaga pada suis inverter. Topologi baru fasa inverter tetap (PSI) ini telah direka menggunakan kawalan sumber arus PLL. Sumber voltan masuk PSI ini telah digunakan daripada voltan DC tinggi penjana elektrostatik (ESG). ESG yang diubah suai ini dapat menghasilkan HVDC dan arus terus yang sederhana. Topologi suis inverter yang dicadang ini dapat mengawal kuasa mikrogrid serta mengurangkan kehilangan dinamik dan statik suis. Ia juga mengurangkan gangguan harmoni frekuensi tinggi dan memperbaiki ketidak-seimbangan sudut fasa. Skim tapisan signal keluar yang rendah pada LCL inverter ini direka bagi mengurangkan total gangguan harmoni sebanyak 1.62%. Litar PSI ini direka dan disimulasi menggunakan perisian MATLAB. Dalam sistem yang dibangunkan ini, 8 kVDCvoltan masuk, 50Hz frekuensi mikrogrid, 10 kHz frekuensi suis angkutan dan 0.85 indeks modulasi telah dipertimbangkan untuk kegunaan. Teknik baru modul suis PSI mikrogrid bersambung yang dicadangkan ini mempunyai kepentingan dalam menstabilkan kuasa dan memperbaiki kecekapan sistem keseluruhan sebanyak 95.52%

An AI based self-moderated smart-home

Smart-home conception has emerged in recent years and played a very important part in the formation of future houses. Making our current homes more adaptable and self-directed is the main focus of smart home research. Achieving these goals won't be possible without giving our today's home enough intelligence to make rational decisions to operate itself which usually we as inhabitants of the home make these decisions in our everyday life to manage our home and achieve comfort that we desire. In this paper we present prototype of a system that overcomes this problem by giving the home enough intelligence to adapt to its inhabitants life style without the need for the inhabitants to exercise authority. The system makes use of multi-agent and prediction techniques to provide intelligent smart-home appliances automation. The final prototype will be downloaded into FPGA chip

Plans For Planar: Phase-Noise Reduction Techniques In Voltage-Controlled Oscillators

To ensure spectral purity in modern RF signal sources, microwave oscillators and voltage-controlled oscillators (VCOs) must be designed to perform with low phase noise. Despite the growth of monolithic microwave integrated circuits (MMICs), microstrip planar technology is still used for developing low-phase-noise VCOs due to its design simplicity and low manufacturing cost. This article reviews the attributes of low-phase-noise VCOs and some recent techniques applied for phase-noise reduction in microstrip planar technology. The major challenge in designing VCOs in microstrip planar technology lies in improving the quality factor (Q) of resonators. Different methods to improve Q are presented here for techniques incorporated with microstrip lines and substrate integrated waveguides (SIWs). The tradeoff involved with the tuning range (TR) of VCOs is also emphasized to introduce the design selectivity for wideband applications