AEEE. 2017, vol. 15

Permanent URI for this collectionhttp://hdl.handle.net/10084/117083

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Now showing 1 - 20 out of 102 results

Effects of Green - Emitting Phosphor (La,Ce,Tb)PO4:Ce:Tb on Luminous Flux and Color Quality of White LED Lamps
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Thao, Nguyen Thi Phuong; Le, Phan Xuan; Tho, Le Van; Vozňák, Miroslav; Anh, Nguyen Doan Quoc
In this paper, we present and analyze the influence of (La,Ce,Tb)PO4:Ce:Tb green phosphor (LaTb) toward the performance of the multi-chip white LED (MCW-LEDs) lamps including color uniformity, lumen output, Color Rendering Index (CRI), and Color Quality Scale (CQS). By mixing the LaTb green phosphor and the YAG:Ce yellow phosphor compounding under condition of 7000 K MCW-LEDs, this new approach can produce a huge meaningful change in lumen output and the angular color distribution of MCWLEDs. We also study the interaction between the concentration and size of the LaTb particles with output flux, color uniformity, CRI, and CQS. The obtained results demonstrate that the higher lumen output, the higher color uniformity enhancement could be attained by adding the LaTb particles with a size range around 6-8 m and the concentration around 1.5 % in phosphor layer. Meanwhile, the decrease of the color rendering value (CRI) and the Color Quality Scale (CQS) tend to be stable and insignificant. In other words, the obtained results provide a prospective method which plays an important role in the development of MCWLED manufacturing technology.
Optical Birefringence Fiber Temperature Sensors in the Visible Spectrum of Light
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Kyselák, Martin; Dvořák, Filip; Maschke, Jan; Vlček, Čestmír
This article describes experimental tests to determine PM fibers Panda style responses to a thermal source with different initial temperature. The aim of this study was to determine the sensitivity of a polarization maintaining fiber to the radiating heat, and to upgrade the space configuration and time response when using the 635 nm light. The sensitivity of the polarization maintaining fiber during excitation of both polarization modes is the principle of this sensor function. This excitation is caused by temperature change and by absorption of thermal radiation. This mechanism is used as an indicator for detection of temperature field disturbance. This article also provides links to previously published results and compares them to the results in this article.
Transmission transparency and potential convergence of optical network solutions at the physical layer for bit rates from 2.5 Gb·s-1 to 256 Gb·s-1
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Agalliu, Rajdi; Lucki, Michal
In this paper, we investigate optical network recommendations GPON and XG-PON with triple-play services in terms of physical reach, number of subscribers, transceiver design, modulation format and implementation cost. Despite trends to increase the bit rate from 2.5 Gb s􀀀1 to 10 Gb s􀀀1 and beyond, TDMPONs cannot cope with bandwidth requirements of future networks. TDM and WDM techniques can be combined, resulting in improved scalability. Longer physical reach can be achieved by deploying active network elements within the transmission path. We investigate these options by considering their potential coexistence at the physical layer. Subsequently, we analyse the upgrade of optical channels to 100 Gb s􀀀1 and 256 Gb s􀀀1 by using advanced modulation formats, which combine polarization division multiplexing with coherent detection and digital signal processing. We show that PDMQPSK format is suitable for 100 Gb s􀀀1 systems and PDM-16QAM is more beneficial at 256 Gb s􀀀1. Simulations are performed in the OptSim software environment.
Optimizing of Passive Optical Network Deployment Using Algorithm with Metrics
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Pehnelt, Tomáš; Lafata, Pavel
Various approaches and methods are used for designing of optimum deployment of Passive Optical Networks (PON) according to selected optimization criteria, such as optimal trenching distance, endpoint attenuation and overall installed fibre length. This article describes the ideas and possibilities for an algorithm with the application of graph algorithms for finding the shortest path from Optical Line Termination to Optical Network Terminal unit. This algorithm uses a combination of different methods for generating of an optimal metric, thus creating the optimized tree topology mainly focused on summary trenching distance. Furthermore, it deals with algorithms for finding an optimal placement of optical splitter with the help of K-Means clustering method and hierarchical clustering technique. The results of the proposed algorithm are compared with existing methods.
Combination of Spatial Domain Filters for Speckle Noise Reduction in Ultrasound Medical Images
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Garg, Amit; Khandelwal, Vineet
The occurrence of speckle noise in medical Ultrasound (US) images poses a big challenge to medical practitioners over last several years. Speckle noise reduces the fine details present in the images and hence make it more difficult to diagnose. In this paper, a novel method based on the combination of three spatial domain filters is presented. The output of these filters is combined on the basis of an Intensity Classifier Map (ICF) formed using Coefficient of Dispersion (CoD) parameter. Experiments were conducted on synthetic and real US images. Quantitative and qualitative analysis of the proposed method is carried out in comparison to other six existing methods. It has been found from the obtained results that proposed method delivers observable improvement in all quantitative parameters undertaken for synthetic US image and in MVR value for real US images. Also, the effectiveness of the proposed method is found to be consistent with qualitative assessment of the denoised images.
OTRA-Based Multi-Function Inverse Filter Configuration
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Singh, Abdhesh Kumar; Gupta, Ashish; Senani, Raj
A new OTRA-based multifunction inverse filter configuration is presented which is capable of realizing low pass, high pass and band pass filters using only two OTRAs and five to six passive elements. To the best knowledge of the authors, any inverse filter configuration using OTRAs has not been reported in the literature earlier. The effect of the major parasitics of the OTRAs and their effect on the performance of the filter have been investigated and measured through simulation results and Monte-Carlo analysis. The workability of the proposed circuits has been confirmed by SPICE simulations using CMOS-based-OTRA realizable in 0.18 m CMOS technology. The proposed circuits are the only ones, which provide simultaneously the following features: use of reasonable number of active elements (only 2), realizability of all the three basic filter functions, employment of all virtually grounded resistors and capacitors and tunability of all filter parameters (except gain factor, H0 for inverse high pass). The centre/cut-off frequency of the various filter circuits lying in the vicinity of 1 MHz have been found to be realizable, which has been verified through SPICE simulation results and have been found to be in good agreement with the theoretical results.
Realization of Current Mode Universal Filter and a Dual-Mode Single Resistance Controlled Quadrature Oscillator Employing VDCC and Only Grounded Passive Elements
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Gupta, Manish; Arora, Tajinder Singh
The manuscript presents a circuit that can act as a universal filter as well as a single resistance controlled oscillator by unpretentiously changing the switch positions. The circuit employs only two active devices and all grounded passive elements. The utilization of only grounded passive components makes this circuit a better choice for integrated circuit implementation. The current mode biquadratic filter offers all the five basic responses along with independent tunability of its quality factor. The dual-mode quadrature sinusoidal oscillator offers explicit current outputs along with voltage outputs. The circuit also offers a simple and uncoupled condition of oscillation and frequency of oscillation. The typical analysis such as non-ideal, sensitivity and parasitic analysis along with the regular simulation results as well as experimental results are exposed here, to strengthen the design idea.
Precise Implementation of CDTA
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Biolek, Dalibor; Vávra, Jiří
The Current Differencing Transconductance Amplifier (CDTA) is a popular active building block for analog signal processing. Since it is not available as a commercial IC, most of the CDTA applications are verified only via simulations or the CDTA is implemented by commercial circuits. The paper deals with CDTA implementation, emphasizing the accuracy, linearity, and dynamic range of the processed signals, and low power consumption. Such a CDTA can be useful wherever these requirements are more relevant than the speed and bandwidth, typically for implementing hardware emulators of memristive systems.
Low Power Differential CMOS Schmitt Trigger with Adjustable Hysteresis
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Jani, Rachna; Oza, Shruti
This paper proposes a novel differential CMOS Schmitt trigger with adjustable hysteresis. The hysteresis of the proposed circuit is generated using cross-coupled pMOS or nMOS transistors, which can be tuned by engineering cross-coupled transistors current. By changing input voltage, the hysteresis window can also be adequately adjusted. Negative feedback has been introduced through CMOS differential amplifier which makes the circuit less sensitive to process, supply voltage and temperature (PVT) deviations. The proposed configuration uses TSMC 0.18 m CMOS technology with 1.8 V supply voltage. Simulation results show that the switching voltage of the circuit can be tuned for target applications.
OTRA Based Piece-Wise Linear VTC Generators and Their Application in High-Frequency Sinusoid Generation
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Oruganti, Sirish; Gilhotra, Yatin; Pandey, Neeta; Pandey, Rajeshwari
This paper proposes methods to generate various types of Linear Voltage Transfer Curves (VTC) using Operational Trans-Resistance Amplifier (OTRA) as the active block. It further goes on to propose methods to multiplex various individual Linear VTCs to obtain any form of Piece-Wise Linear Voltage Transfer Curves (PWL), which find many applications in the world of circuitry. One particular application has been highlighted, i.e. generation of High-Frequency Sinusoids. Simulations of the Circuits proposed via Cadence Virtuoso, using TowerJazz’s 180 nm Technology Node have been reported, which satisfy the aim behind its development.
Electronically Controllable Sinusoidal Oscillators Employing VDIBAs
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Pushkar, Kanhaiya Lal
Two new electronically controllable sinusoidal oscillators each employing two Voltage Differencing Inverting Buffered Amplifiers (VDIBAs), two capacitors, and a single resistor have been proposed. The presented oscillators offer independent electronic control of Condition of Oscillation (CO) and Frequency of Oscillation (FO), and low active and passive sensitivities. The effect of non-idealities of the VDIBAs on the proposed oscillators is also investigated. The validity of the proposed structures has been confirmed by SPICE simulation with TSMC 0.18 m process parameters.
Stability Analysis of a Novel Switched Inductor Based Quadratic Boost DC-DC Converter
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Jayachandran, Divya Navamani; Krishnasamy, Vijayakumar; Ramiah, Jegatheesan
This paper proposes a new Switched Inductor based Quadratic Boost (SLQB) converter. The theoretical study for control design is carried out in detail. Small signal dynamic analysis of the proposed topology is obtained by State-Space averaging technique to investigate the closed-loop performance of SLQB converter. Ziegler-Nichols’ closed loop tuning method is adapted to design the controller and analyze the closed loop performance. The theoretically derived transfer functions divulged a perfect matching with simulation results obtained from circuit simulator, spice. The effectiveness and adaptability of the SLQB converter are confirmed with high gain DC-DC converters belonging to the SL family. The stability study is carried out by MATLAB software, and the respective graphs are obtained to analyze the open loop and closed loop performance of the derived converter.
A Novel Realization of Low-Power and Low-Distortion Multiplier Circuit with Improved Dynamic Range
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Naderi Saatlo, Ali; Amiri, Abolfazl
A novel topology of four-quadrant analog multiplier circuit is presented in this paper. The voltage mode technique is employed to design the circuit in CMOS technology. The dynamic input and output ranges of the circuit are improved owing to the fact that the circuit works in the saturation region not in weak inversion. Also the proposed multiplier is suitable for low voltage operation and its power consumption is relatively low. In order to verify the performance of the proposed circuit, performance of the circuit affected by second order effects including transistor mismatch and mobility reduction is analyzed in detail. It will be shown that any conceivable mismatch in the transistor parameters leads to second harmonic distortion. Additionally, the effect of mobility reduction in the third harmonic distortion will be computed. In order to simulate the circuit, Cadence and HSPICE software are used with TSMC level 49 (BSIM3v3) parameters for 0.18 m CMOS technology, where under supply voltage of 1.5 V, total power consumption is 44 W, the corresponding average nonlinearity remains as low as 1 %, and the input range of the circuit is 400 mV.
A State Evaluation Adaptive Differential Evolution Algorithm for FIR Filter Design
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Wang, Yong; Teng, Zhaosheng; Wen, He; Li, Jianmin; Martinek, Radek
Due to conventional differential evolution algorithm is often trapped in local optima and premature convergence in high dimensional optimization problems, a State Evaluation Adaptive Differential Evolution algorithm (SEADE) is proposed in this paper. By using independent scale factor on each dimension of optimization problem, and evaluating the distribution of population on each dimension, the SEADE correct the control parameters adaptively. External archive and a moving window evaluation mechanism on evolution state are introduced in SEADE to detect whether the evolution is stagnation or not, and with the help of opposition-based population, the algorithm can jump out of local optima basins. The results of experiments on several benchmarks show that the proposed algorithm is capable of improving the search performance of high dimensional optimization problems. And it is more efficient in design FIR digital filter using SEADE than conventional
Modelling of Stray Currents Near a Railway Platform
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Zajaczek, Stanislav; Cigánek, Jiří; Mohylová, Jitka; Ďurica, Maroš
The article describes simulations of the occurrence of stray currents in the vicinity of a SUDOPtype railway platform. Stray currents occur in the vicinity of a railway platform during the passage of a railway vehicle. In a fault-free state, all metallic parts are separated from the rail by means of a surge arrester. In the case of a breakdown of the surge arrester, the full voltage which is on the rail at the time of the passing railway vehicle may also pass onto the metallic parts. The surge arresters are checked every 6 months during maintenance work on the overhead lines according to Annex No. 1 of SZDC internal regulation E 500. The article, therefore, carries out a simulation of stray currents in exactly this type of breakdown. In addition, to the model, we included the influence of the outdoor lighting cable which is located in the ground under the platform. For the purposes of solving the model, we are using a commercially available program which solves partial differential equations and uses the finite element method for calculation.
Simulation of Start-Up Behaviour of Induction Motor with Direct Online Connection
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Kocman, Stanislav; Orság, Petr; Pečínka, Pavel
In this paper, a simulation of dynamical start-up behaviour of induction motor with direct online connection to the network has been carried out using COMSOL Multiphysics software. The simulated model of the motor mainly consists of a basic FEM model, an electrical model with stator and rotor circuits and a mechanical model. The chosen motor parameters both electrical and mechanical have been studied and their results presented in this paper. An experimental measurement of the start-up transient of the no-loaded motor was carried out and some its results have been compared to the results from the simulated motor model and analysed.
Application of Sensorless Sliding Mode Observer in Control of Induction Motor Drive
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Dong, Chau Si Thien; Vo, Hau Huu; Tran, Thinh Cong; Brandštetter, Pavel; Šimoník, Petr
Induction motors are widely used in an industry and it is necessary to improve control methods for induction motors to increase the efficiency of them. In this paper, sliding mode controllers are proposed instead of traditional PI controllers in vector control of induction motor drives. Moreover, rotor speed is estimated by a sliding mode observer. In addition, the robustness of control and observer algorithms are also proved by Lyapunov’s criterion. The experiments are obtained in different speed changes of an induction motor drive. These experimental results confirm the dynamic properties of a sensorless sliding mode control of an induction motor drive.
A Novel Multi-Objective Bat Algorithm for Optimal Placement and Sizing of Distributed Generation in Radial Distributed Systems
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Remha, Souhaib; Chettih, Saliha; Arif, Salem
In the few last decades, Distribution Generation (DG) has drawn a great attention by researchers around the world in the field of Radial Distributed Systems (RDSs). Generally, the optimal placement is based on the maximization of the Voltage Stability Index (VSI) and the optimal sizing is based on the minimization of the Total Active Power Losses (TAPLs). Hence, a Multi-Objective Optimization Problem (MOOP) is proposed to achieve the both mentioned objectives. For this purpose, a new simple optimization algorithm known as Bat Algorithm (BA) based on Weight Sum Method (WSM) has been used to resolve the MOOP. Then, the Fuzzy Based (FB) technique is employed to find the Best Compromise Solution. This paper also provides a comparison between the proposed algorithm and other recently published methods. From the obtained results, the advantage of the proposed algorithm is clearly observed from multiple points of view such as enhancement of Voltage Profile (VP), decreasing of the TAPL, and the maximization of the VSI. The investigations have been carried out on a standard IEEE 12-bus, 33-bus, 69-bus, and 85-bus test feeders.
Optimal Number, Location, and Size of Distributed Generators in Distribution Systems by Symbiotic Organism Search Based Method
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Nguyen-Phuoc, Tri; Vo, Dieu Ngoc; Tran-The, Tung
This paper proposes an approach based on the Symbiotic Organism Search (SOS) for optimal determining sizing, siting, and number of Distributed Generations (DG) in distribution systems. The objective of the problem is to minimize the power loss of the system subject to the equality and inequality constraints such as power balance, bus voltage limits, DG capacity limits, and DG penetration limit. The SOS approach is defined as the symbiotic relationship observed between two organisms in an ecosystem, which does not need the control parameters like other meta-heuristic algorithms in the literature. For the implementation of the proposed method to the problem, an integrated approach of Loss Sensitivity Factor (LSF) is used to determine the optimal location for installation of DG units, and SOS is used to find the optimal size of DG units. The proposed method has been tested on IEEE 33-bus, 69-bus, and 118-bus radial distribution systems. The obtained results from the SOS algorithm have been compared to those of other methods in the literature. The simulated results have demonstrated that the proposed SOS method has a very good performance and effectiveness for the problem of optimal placement of DG units in distribution systems.
Congestion Management Based on Optimal Rescheduling of Generators and Load Demands Using Swarm Intelligent Techniques
(Vysoká škola báňská - Technická univerzita Ostrava, 2017) Salkuti, Surender Reddy
This paper presents the Congestion Management (CM) methodologies and how they get modified in the new competitive framework of electricity power markets. When the load on the system is increased or when some contingency occurs in the system, some of the lines may become overloaded. Thus, the loadability of the system should be increased by generating and dispatching the power optimally for the secure operation of power system. In this paper, the CM problem is solved by using the optimal rescheduling of generating units and load demands, and the Swarm intelligent techniques are used to handle this problem. Here, the CM problem is solved by using the Particle Swarm Optimization (PSO), Fitness Distance Ratio PSO (FDRPSO) and Fuzzy Adaptive-PSO (FA-PSO). First, the generating units are selected based on sensitivity to the over-loaded transmission line, and then these generators are rescheduled to remove the congestion in the transmission line. This paper also utilizes the demand response offers to solve the CM problem. The effectiveness of the proposed CM methodology is examined on the IEEE 30 bus and Indian 75 bus test systems.

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