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IMPLEMENTATION OF IMPEDANCE SOURCE INVERTER SYSTEM FOR PHOTOVOLTAIC APPLICATIONS
Get PDFThis paper presents a high performance, low cost inverter for photovoltaic systems based on Impedance-source concept. Traditional Voltage-source inverter and Current-source inverter has improved to the new Z-source inverter, with a unique X-shaped network in it. This Impedance-source inverter can provide a single stage power conversion concept where as the traditional inverter requires two stage power conversion for renewable energy applications. A new low cost solar cell powered Z-source inverter system is simulated and the results are compared with the traditional Voltage-source inverter system. Performance analysis, simulation and comparison have been confirmed that the Z-source inverter system is more appropriate for photovoltaic application than their counterparts. Hardware implementation is done to validate the proposed system
DESIGN OF IMPROVED PERFORMANCE RECTANGULAR MICROSTRIP PATCH ANTENNA USING PEACOCK AND STAR SHAPED DGS
Get PDFIn this paper, two novel defected ground structures (DGS) are proposed to improve the return loss, compactness, gain and radiation efficiency of rectangular microstrip patch antenna. The performance of antenna is characterized by the shape, dimension & the location of DGS at specific position on ground plane. By incorporating a peacock shaped slot of optimum geometries at suitable location on the ground plane, return loss is enhanced from -23.89 dB to -43.79 dB, radiation efficiency is improved from 97.66% to 100% and compactness of 9.83% is obtained over the traditional antenna .Simulation results shows that the patch antenna with star shaped DGS can improve the impedance matching with better return loss of -35.053 dB from -23.89 dB and compactness of 9% is achieved. In the end comparison of both DGS shapes is carried out to choose one best optimize one. The proposed antennas are simulated and analyzed using Ansoft HFSS (version 11.1) software
AUTONOMOUS RECONFIGURATION OF IP CORE UNITS USING BLRB ALGORITHM
Get PDFIn commercial architectures, the routing consumes most of the chip area, and is responsible for most of the circuit delay. In this paper a new technique of reconfiguring FPGA circuits is proposed. The proposed technique uses BLRB approach for reconfiguring the FPGA. By this approach the routing path is less and the overall delay required to recover from fault is very less. Whenever any fault occurs the spare is selected in such way that whichever spare is nearer is chosen for reconfiguration. By selecting the nearest spare the routing path is decreased. In this method multiple faults are reconfigured at a time and the reconfigured bits are generated
A LAYERED DECODING ARCHITECTURE FOR LDPC DECODER WITH LOW ENERGY CONSUMPTION
Get PDFLow-density parity-check (LDPC) decoder requires large amount of memory access which leads to high energy consumption. To reduce the energy consumption of the LDPC decoder, memory-bypassing scheme has been proposed for the layered decoding architecture which reduces the amount of access to the memory storing the soft posterior reliability values. In this work, we present a scheme that achieves the optimal reduction of memory access for the memory bypassing scheme. The amount of achievable memory bypassing depends on the decoding order of the layers. We formulate the problem of finding the optimal decoding order and propose algorithm to obtain the optimal solution. We also present the corresponding architecture which combines some of memory components and results in reduction of memory area. The proposed decoder was implemented in TSMC 0.18 m CMOS process. Experimental results show that for a LDPC decoder targeting IEEE 802.11n specification, the amount of memory access values can be reduced by 12.9–19.3% compared with the state-of-the-art design. At the same time, 95.6%–100% hardware utilization rate is achieved
DESIGN OF ON-CHIP BUS OCP PROTOCOL WITH BUS FUNCTIONALITIES
Get PDFThe need for on-chip bus protocols are increased drastically for efficient and lossless communication among large number of IP cores of SOC design. This paper proposes a high-performance, highly scalable, bus- independent interface between IP cores named as Open Core Protocol-International partnership. The Open Core Protocol (OCP) is a core centric point to point protocol which provides lossless communication and reduces design time, design risk, and manufacturing costs for SOC designs . Main property of OCP is that it can be configured with respect to the application required. The OCP is chosen because of its advanced supporting features such as configurable sideband control signaling and test harness signals, when compared to other core protocols. The OCP defines a point- to-point interface between two communicating entities such as IP cores and bus interface modules. One entity acts as the master of the OCP instance, and the other as the slave .In this paper, the most efficient bus architecture was adopted to support most advanced bus functionalities including simple transactions, burst transactions, pipelined transactions, and out-of-order transactions with respect to its suitable application in the real time product. The Open Core Protocol (OCP) was designed and the hardware modeling for that architecture was done using VHDL. This design is Simulated and Synthesized. An experimental result shows the efficiency of the proposed bus architecture and interface
FAULT DIAGNOSIS OF POWER TRANSFORMER BASED ON DISSOLVED GAS ANALYSIS AND ADAPTIVE NEURO-FUZZY INFERENCE SYSTEM
Get PDFPower Transformers are a vital link in a power system. Well-being of power transformer is very much important to the reliable operation of the power system. Dissolved Gas Analysis (DGA) is one for the effective tool for monitoring the condition of the transformer. To interpret the DGA result multiple techniques are available.IEC codes are developed to diagnose transformer faults. But there are cases of errors and misleading judgment due to borderline and multiple faults. Methods were developed to solve this problem by using fuzzy membership functions to map the IEC codes and heuristic experience to adjust the fuzzy rule. This paper proposes a neuro-fuzzy method to perform self learning and auto rule adjustment for producing best rule
POST INSULATOR DESIGN OPTIMIZATION IN MEDIUM VOLTAGE SWITCHGEAR
Get PDFThere has been constant development in the energy sector. As the trend of SMART grid is increasing, modern power systems require smarter and reliable switchgear. In this view, the optimum design of switchgear and components acquired prime importance. This can be achieved using various optimization techniques. In this paper, novel optimum design of post insulator is proposed and carried out. The design gives a standard value of capacitance for the indicating system and also solves problem of partial discharge in Indian system. The design is first carried out using 3D MAXWELL software tool for 33kv post insulator which gives drawing in AUTOCAD. The output design parameters obtained in 3D MAXWELL are used for optimization in MATLAB
AN ASSESSMENT OF POWER-USE PROFILE IN DESKTOP COMPUTERS
Get PDFKnowing the actual power requirement of each individual component in a desktop computer is useful when sizing a power supply or when upgrading the PC. In this paper the power demand by various components within six different computer systems was investigated. Measurements of the actual current drawn from each voltage rail when idle and when in use were made and the data examined. The results obtained showed that the total power drawn at idle and on CPU load test was mainly due to the load demand on the +12V rails and this varied significantly between the computer systems; meanwhile +5V and +3.3V lines drew very little power and the total power consumed did not vary significantly between systems on idle state. The assessment revealed that it is highly unlikely that a modern computer system will ever overload either the +5V or +3.3V rails of an ATX12V 2.x compliant power supply; the +12 rails on the other hand, are very heavily used especially under load. Thus, it is very likely that the ratings for the +12V rails is more important than the total wattage rating when it comes choosing a power supply unit for a computer system
SPLIT MLSE ADAPTIVE EQUALIZATION IN SEVERELY FADED RAYLEIGH MIMO CHANNELS
Get PDFThis paper presents an overview of adaptive equalization used in multiple-input-multiple-output (MIMO) wireless systems. In this paper, we consider two-user transmission over a Rayleigh frequency selective fading channel, in which the Channel State Information (CSI) is known by the receiver. Subject to an average transmit power constraint, we study the performance with Rayleigh fading. Besides an approximation result of such performance is proposed, and by conducting numerical comparison it is shown that our suggested approximation result has a better performance in approximating Rayleigh fading using Maximum-Likelihood Sequence Estimation (MLSE) algorithm. We here proposed a split MLSE adaptive equalization for use in faded MIMO channels. The proposed system is analyzed in terms of bit error rate (BER) with signals to noise ratio (SNR). Evaluation and comparison of the performances of MIMO system in the Additive White Gaussian Noise (AWGN) channel, and Rayleigh fading channel are provided. Experimental results show that the proposed split MLSE based adaptive equalization gives better results compared to composite equalization done traditionally
ARTIFICIAL NEURAL NETWORK AIDED RETINA BASED BIOMETRIC IDENTIFICATION SYSTEM
Get PDFArtificial Neural Network (ANN)s are efficient means of prediction, optimization and recognition. Retina is a unique biometric pattern that can be used as a part of a verification system. An ANN can be configured and trained to handle such variations observed in the texture of the retina. The specialty of the work is associated with the fact that if the ANN is configured properly it can tackle the variations in the retinal images and that way provides the insights for developing a system which requires the samples for verification and authorization. A system designed to provide authentication decision using the input can be a reliable means of verification. Such a system designed using ANN and using retina input is described here. Experimental results show that the system is reliable enough for considering it as a part of a verification mechanism