Smps

This paper presents the effect of the output capacitor on the EMI spectrum of radiation, the output voltage ripple and the efficiency of a SEPIC Converter. Two SEPIC converters were designed with LT1871 (Linear Technology) and LM2577 (National Semiconductor), for an input voltage of 4 to 16V, the output voltage of 5V, output current of 0.5A, and the switching frequency of 52kHz. The functionality of the converter was simulated in LTspice IV and OrCAD, and it was compared with the experimental results. It was measured the level of EMI spectrum, the output voltage ripple and the efficiency of the converter with different types of capacitors. An acceptable output voltage ripple, which respects the standards FCC Class A and Class B, was obtained with solid and tantalum capacitors in parallel with small MLCC capacitors. The minimum of ripple and frequency spectrum was obtained by adding a LC Filter to the output of the converter. With this filter the converter respects the standard SAE J...

In this paper a novel digital controller and modified buck converter for improving heavy-to-light load transient response of low-power low-voltage dc-dc converters is introduced. The system is primarily designed for point-of-load (PoL) converters providing low regulated voltages for digital loads. In conventional buck topologies, the low output voltage, often below 1 V, severely limits the inductor current slew rate during the transients. To overcome this physical limitation, a modification is introduced whereby during heavy-to-light transients, the inductor current is, by the means of two extra switches, steered into the source and at the same time, the slew-rate of the current is significantly increased. The steering action is governed by a digital controller. The effectiveness of the system is verified on an FPGA-controlled, 12 V to 0.9 V, 10 W, experimental prototype. The results show that the steered-inductor digitally controlled buck converter has much shorter settling time and provides 2.8 times smaller overshoot than the conventional buck.

This paper addresses classification problems in which the class membership of training data is only partially known. Each learning sample is assumed to consist in a feature vector and an imprecise and/or uncertain “soft” label m i defined as a Dempster-Shafer basic belief assignment over the set of classes. This framework thus generalizes many kinds of learning problems including supervised, unsupervised and semi-supervised learning. Here, it is assumed that the feature vectors are generated from a mixture model. Using the General Bayesian Theorem, we derive a criterion generalizing the likelihood function. A variant of the EM algorithm dedicated to the optimization of this criterion is proposed, allowing us to compute estimates of model parameters. Experimental results demonstrate the ability of this approach to exploit partial information about class labels.

COM) has proved to be a useful custom power device to eliminate harmonic components and to compensate reactive power for balanced /unbalanced linear/nonlinear loads. This paper presents a novel control strategy to calculate the reference compensation current of three phase DSTATCOM under distorted utility condition at instantaneous state. In this proposed approach digital FIR filters with cut off frequency 25,100 Hz of direct form structure have been implemented on FPGA to make the process faster. The performance of the system simulated in Matlab Platform and evaluated considering the source current total harmonic distortion. The VHDL design has been implemented using ISE10.1 tool from Xilinx. This is tested on a board with hardware configuration such as FPGA- XC2VP4 with on chip PowerPC-405 Processor, ADC AD9240-14 bit 10MSPS analog input channel, DAC AD7541-12-bit of conversion time–100ns with System clock 40 MHz. Keywords—Field programmable gate Array; Constant

The article highlights and optimizes a controller for the single ended primary inductance converter (SEPIC) direct current-direct current (DC-DC) converter. The SEPIC converter adjusts a range of dc input voltages and delivers a constant and stable output voltage. Three different models of the SEPIC converter are presented in order to derive its transfer function. Being a 4 th order, an approximation method for the reduction of this transfer function to 2 nd and 1 st order is implemented. Two methods for controlling the converter are presented, the first one is based on guessing techniques and the second explains the design steps of the controller based on the internal model control (IMC). Furthermore, an improvement on the IMC controller is proposed and results were shown and discussed. IMC is based on integrating the "process model" in the control operation of the actual system. By using an approximation of the original transfer function of the system, it is expected that the IMC control will be able to achieve the desired results. Control schemes of the SEPIC will be presented and results will be shown. The response of the controller was tested with mathematical models for batteries and supercapacitors in MATLAB, as non-ideal DC-sources, and results were presented.

For the up-coming generations of power-supply systems, the load located area power-supply sources are an effective one, in terms of our requirements: simplicity, integrity, battery-backup, etc. This could follow the Normalization of power factor & Reducing THD% values on input current, which makes us to add an essential to include a power-factor correction unit at supply side in these new typical topologies. This Proposed architecture presents an integrated battery manage system which can also offers PF correction along with Galvanic-Isolation of battery in a humble single structure. [3] The proposed scheme has the reliable characters like increased efficiency, compact circuit and reduced costs associated with a traditional standalone multiple-stages UPS with PFC. This paper addresses the UPS action, the analysis and simulation results of Proposed UPS scheme.

This paper introduces a new switching mode power supply with the following properties: zero-voltage switching; pulse-width modulation at constant frequency; three-phase input with high power factor; and low input current distortion, using a single power stage formed by a full-bridge DC to DC power converter. Circuit operation, theoretical analysis, simulation, and design procedures and examples are presented. A laboratory prototype rated at 1.5 kW and operating at 100 kHz has been fabricated and tested successfully. The corresponding experimental results are included in the paper

This paper introduces a new switching mode power supply with the following properties: zero-voltage switching; pulse-width modulation at constant frequency; three-phase input with high power factor; and low input current distortion, using a single power stage formed by a full-bridge DC to DC power converter. Circuit operation, theoretical analysis, simulation, and design procedures and examples are presented. A laboratory prototype rated at 1.5 kW and operating at 100 kHz has been fabricated and tested successfully. The corresponding experimental results are included in the paper

In this paper a complete multi input-multi output state-space average model for the KY buck-boost converter is presented. The introduced model includes the most of the regulator’s parameters and uncertainties. In modeling, the load current is assumed to be unknown, and it is assumed that the inductor, capacitor, diode and regulator active switches are non ideal and have a resistance in conduction condition. Some other non ideal effects look like voltage drop of conduction mode of the diode and active switches are also considered. After presenting the complete model, the KY buck-boost converter Benchmark circuit is simulated in PSpice and its results are compared with our model simulation results in MATLAB SIMULINK. The results show the merit of our model.

Important biological activities have been described for mesoionic compounds. We previously reported that MI-D (4-phenyl-5-(4-nitro-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride) inhibited the respiratory chain, collapsed the transmembrane potential, and ...

For the up-coming generations of power-supply systems, the load located area power-supply sources are an effective one, in terms of our requirements: simplicity, integrity, battery-backup, etc. This could follow the Normalization of power factor & Reducing THD% values on input current, which makes us to add an essential to include a power-factor correction unit at supply side in these new typical topologies. This Proposed architecture presents an integrated battery manage system which can also offers PF correction along with Galvanic-Isolation of battery in a humble single structure. [3] The proposed scheme has the reliable characters like increased efficiency, compact circuit and reduced costs associated with a traditional standalone multiple-stages UPS with PFC. This paper addresses the UPS action, the analysis and simulation results of Proposed UPS scheme.

Several methods for the practical representation of imprecise probabilities exist such as Ferson’s p-boxes, possibility distributions, Neumaier’s clouds, and random sets. In this paper some relationships existing between the four kinds of representations are discussed. A cloud as well as a p-box can be modelled as a pair of possibility distributions. We show that a generalized form of p-box is a special kind of belief function and also a special kind of cloud.

A soft-switching converter with dual resonant structures is presented in this article. The dual resonant tanks are composed of the leakage inductors and resonant capacitors to achieve a zero-current-switching (ZCS) turn-off mechanism for diodes on the secondary side of the transformer. Moreover, the voltage stresses of power switches are clamped by the active clamp circuit on the primary side of the transformer. The active clamp circuit has not only absorbed the energy stored in the leakage inductor but also creates a zero-voltage-switching turn-on feature for power switches. Hence, the reverse-recovery problem can be eliminated. The operational principles, design considerations and realisation are discussed. Finally, the experimental results from a 400 W prototype are presented to confirm the effectiveness of the proposed converter.

This paper addresses classification problems in which the class membership of training data is only partially known. Each learning sample is assumed to consist in a feature vector and an imprecise and/or uncertain “soft” label m i defined as a Dempster-Shafer basic belief assignment over the set of classes. This framework thus generalizes many kinds of learning problems including supervised, unsupervised and semi-supervised learning. Here, it is assumed that the feature vectors are generated from a mixture model. Using the General Bayesian Theorem, we derive a criterion generalizing the likelihood function. A variant of the EM algorithm dedicated to the optimization of this criterion is proposed, allowing us to compute estimates of model parameters. Experimental results demonstrate the ability of this approach to exploit partial information about class labels.

This paper addresses classification problems in which the class membership of training data is only partially known. Each learning sample is assumed to consist in a feature vector and an imprecise and/or uncertain “soft” label m i defined as a Dempster-Shafer basic belief assignment over the set of classes. This framework thus generalizes many kinds of learning problems including supervised, unsupervised and semi-supervised learning. Here, it is assumed that the feature vectors are generated from a mixture model. Using the General Bayesian Theorem, we derive a criterion generalizing the likelihood function. A variant of the EM algorithm dedicated to the optimization of this criterion is proposed, allowing us to compute estimates of model parameters. Experimental results demonstrate the ability of this approach to exploit partial information about class labels.