IMPLEMENTATION OF ISOLATED DC-DC CONVERTERS FOR SMPS

Communications - Scientific letters of the University of Zilina, 2013

2019

This paper summarizes the analysis of different modifications in SEPIC converter with snubber circuits. There are different snubber circuits used in dc-dc converters for the protection purpose. The main purpose of snubber circuit is to provide protection against the di/dt and dv/dt at the time of switching of power semiconductor devices. The snubber circuit is generally the combination of active and passive components and mostly passive snubber circuits are used for the protection purpose of power semiconductor devices. The proposed snubber circuit consists of the combination of inductors, capacitors and diodes which provides better output than other snubber circuits used in SEPIC converter. The analysis is done on the basis of output voltages of different converters at different duty cycles. The results show that proposed converter provides better output than others providing higher static gain. The duty cycles are controlled with the help of pulse generator using MATLAB simulink.

A novel single-stage single-switch isolated converter is proposed for attaining high power factor and wide voltage conversion range. This converter interfaces a buck-boost type PFC circuit with a buck type Dc-Dc regulator to process the input power in a single step. By this integration, the proposed converter is able to attain unity input power factor, wide voltage conversion range, low switching voltage stresses and high efficiencies. By isolating the converter non-inverted output voltage is obtained which is an advantage over non-isolated topologies. The input buck-boost stage is operated in discontinuous conduction mode (DCM) to attain high input power factor and the output buck stage is operated in continuous conduction mode (CCM). A simple single closed loop voltage feedback controller is used to get well-regulated and fast output voltage response. A detailed principle operation and design of converter has been analysed theoretically. The performance of the proposed converter is simulated by using MATLAB-SIMULINK software to validate the simulation results with the experimental results.

iaeme

The analysis of open and closed loop controlled DC-DC converter in SMPS system is analyzed in this paper. A new model of soft switching DC-DC converter topology with circuit is presented in this paper for the switching mode power supply applications. It is a type of power converter. Such electronic devices often contain several sub-circuits, each with its own voltage level require different from that supplied by the battery or an external. Additionally, the battery voltage declines as its stored power is drained. SMPS DC to DC converters offer a method to increase voltage from a partially lowered battery voltage thereby saving space instead of using multiple batteries to accomplish the same thing and the UPS operation at different modes are analyzed

iaeme

The analysis of open and closed loop controlled DC-DC converter in SMPS system is analyzed in this paper. A new model of soft switching DC-DC converter topology with circuit is presented in this paper for the switching mode power supply applications. It is a type of power converter. Such electronic devices often contain several sub-circuits, each with its own voltage level require different from that supplied by the battery or an external. Additionally, the battery voltage declines as its stored power is drained. SMPS DC to DC converters offer a method to increase voltage from a partially lowered battery voltage thereby saving space instead of using multiple batteries to accomplish the same thing and the UPS operation at different modes are analyzed

The power switches are the heart of every power converter. Their operation will directly determine the reliability and efficiency of the product. To enhance the performance of the switching circuit of power converters, snubbers are placed across the power switches to suppress voltage spikes and damp the ringing caused by circuit inductance when a switch opens. Proper design of the snubber can result in higher reliability, higher efficiency and lower EMI. Among many different kinds of snubbers, the resistor-capacitor (RC) snubber is the most popular snubber circuit. This article explains why a snubber is needed for power switches. Some practical tips for an optimum snubber design are provided as well. Figure 1: Four basic power switching circuits.

Advances in Electrical and Computer Engineering, 2017

A new concept for reducing the losses in a boost converter is described. With the help of an auxiliary switch and a resonant circuit, zero-voltage switching at turn-off and zerocurrent switching during turn-on are achieved. The modes of the circuit are shown in detail. The energy recovery of the turn-off is analyzed and the recovered energy is calculated; an optimized switching concept therefore is described. The influence of the parasitic capacity of the switch is discussed. Dimensioning hints for the converter and the design of the recuperation circuit are given. A bread-boarded design shows the functional efficiency of the concept.

In this paper the design and implementation of DCDC converter based SMPS for a telecommunication system is presented. A high frequency transformer is used to provide the galvanic isolation between the input and output. A complete design methodology of high frequency transformer used for fullbridge buck derived topology is presented. The operating modes, analysis, and design considerations are explained for the proposed converter. Simulation and experimental results are also presented to demonstrate the performance of the proposed converter. Keywords—High frequency isolation; Single-stage converter; Power factor correction (PFC); Full-bridge buck converter; SMPS

IET Circuits, Devices & Systems, 2019

Here, a new active snubber cell for high-power isolated pulse-width-modulated (PWM) DC-DC converters is proposed. All semiconductor power devices in the proposed converters operate with full soft switching under a very wide load range, and they are not exposed to any voltage and current stress. The main switches turn on with zero-voltage transition (ZVT) and turn off with zero-voltage switching (ZVS). The auxiliary switches turn on with zero-current switching (ZCS) and turn off with ZVS. The theoretical analysis and design procedure for the proposed active snubber cell are carried out in detail and are verified with a half-bridge (HB) converter implementation having 20V output voltage, 50 A output current, and 80 kHz switching frequency. The overall efficiency of the HB DC-DC converter is increased from about 83% in the hard switching condition to about 90% thanks to the proposed active snubber cell.

At present the majority of power supplies or power converters use switch-mode technology. Higher switching frequencies allow reduction of the magnetic component sizes with PWM switching converters but cause higher switching losses and greater electro-magnetic interference. To reduce these switching losses active or passive soft-switching methods are used in various applications.This paper presents a passive lossless soft-switching snubber for telecom power supplies. Simulation results are given to demonstrate the validity and features of the snubber.