scholarly journals Soft Switching DC Converter for Medium Voltage Applications

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 449 ◽  
Author(s):  
Bor-Ren Lin
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Soft Switching ◽  
Parallel Structure ◽  
Dc Microgrid ◽  
Medium Voltage ◽  
Voltage Balance ◽  
Power Switches ◽  
Asymmetric Pulse ◽  
Secondary Side

A dc-dc converter with asymmetric pulse-width modulation is presented for medium voltage applications, such as three-phase ac-dc converters, dc microgrid systems, or dc traction systems. To overcome high voltage stress on primary side and high current rating on secondary side, three dc-dc circuits with primary-series secondary-parallel structure are employed in the proposed converter. Current doubler rectifiers are used on the secondary side to achieve low ripple current on output side. Asymmetric pulse-width modulation is adopted to realize soft switching operation for power switches for wide load current operation and achieve high circuit efficiency. Current balancing cells with magnetic component are used on the primary side to achieve current balance in each circuit cell. The voltage balance capacitors are also adopted on primary side to realize voltage balance of input split capacitors. Finally, the circuit performance is confirmed and verified from the experiments with a 1.44 kW prototype.

A Novel Soft Switching Based Fuzzy Logic Control for Single Phase Inverter

2014 ◽  
Vol 573 ◽  
pp. 143-149
Author(s):  
N. Ismayil Kani ◽  
B.V. Manikandan ◽  
Prabakar Perciyal
Keyword(s):  
Fuzzy Logic ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Soft Switching ◽  
Switching Frequency ◽  
Pwm Inverter ◽  
Zero Voltage Switching ◽  
Control Scheme ◽  
Zero Voltage ◽  
Voltage Switching

—This The Pulse Width Modulation (PWM) DC-to-AC inverter has been widely used in many applications due to its circuit simplicity and rugged control scheme. It is however driven by a hard-switching pulse width modulation (PWM) inverter, which has low switching frequency, high switching loss, high electro-magnetic interference (EMI), high acoustic noise and low efficiency, etc. To solve these problems of the hard-switching inverter, many soft-switching inverters have been designed in the past. Unfortunately, high device voltage stress, large dc link voltage ripples, complex control scheme and so on are noticed in the existing soft-switching inverters. This proposed work overcomes the above problems with simple circuit topology and all switches work in zero-voltage switching condition. Comparative analysis between conventional open loop, PI and fuzzy logic based soft switching inverter is also presented and discussed. Keywords—Zero voltage switching, Inverter, Dc link, PI controller, Fuzzy logic system control ,Modulation strategy, Soft switching

scholarly journals A New Configuration of Three-Level ZSI Using Transistor Clamped Topology

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1469
Author(s):  
Santosh Sonar
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Performance Degradation ◽  
Space Vector ◽  
Power Semiconductors ◽  
Power Switches ◽  
Modulation Schemes

In this paper, a three-level ZSI (impedance source inverter) based on transistor clamped theory is proposed. It uses the least number of switch counts and associated gate circuitry among all existing topologies of three-level ZSI without any performance degradation. The existing three-level ZSI topologies require three power switches to be turned ON for upper-lower shoot-through (ULST), and four power switches to be turned ON for full dc-link shoot-through (FST). However, with the proposed configuration, upper–lower shoot-through (ULST) and full dc-link shoot-through (FST) is inserted by turning ON only two power semiconductors. A comparison between diode clamped, transistor clamped, and t-type is presented. The proposed topology can realize any of the existing sine-triangle- or space vector-based PWM (pulse width modulation) schemes, and all existing configurations of three-level ZSI can merge into the proposed inverter configuration.

scholarly journals An Investigation on the Performance of Random PWM Controlled Converters

2015 ◽  
Vol 5 (6) ◽  
pp. 876-884 ◽  
Author(s):  
R. Jadeja ◽  
A. Ved ◽  
S. Chauhan
Keyword(s):  
Electromagnetic Interference ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Acoustic Noise ◽  
Renewable Energy Sources ◽  
Torque Ripple ◽  
Harmonic Spectrum ◽  
Switching Loss ◽  
Random Pulse ◽  
Power Switches

This paper provides an insight on various random pulse width modulation techniques and their effect on spreading the harmonic spectrum for various applications like drives, hybrid electric vehicles and renewable energy sources, for two level as well as three level inverter. Acoustic noise reduction, electromagnetic interference conducted and torque ripple are obvious advantages of random pulse width modulation (PWM). PWM converters with multilevel topology can meet with global quality standards for power supplies. The random PWM technique provides additional advantages. Among others, it may be implemented to achieve switching loss equalization in power switches for cascaded H-Bridge multilevel inverters. This paper provides in depth understanding for different random PWM techniques and their applications.

scholarly journals A Simplified PWM Technique for Reduced Switch Count Multilevel Inverter

2018 ◽  
Vol 9 (3) ◽  
pp. 711
Author(s):  
Adireddy Ramesh, ◽  
O. Chandra Sekhar ◽  
M. Siva Kumar
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Cost ◽  
High Harmonic ◽  
Harmonic Distortion ◽  
Wave Form ◽  
Medium Voltage ◽  
Multilevel Inverters ◽  
Voltage Application ◽  
Protection Circuits

<p>Penetration of multilevel inverters (MLI) in to high power and medium voltage application has been increasing because of its advantages. The conventional two levels inverter has high harmonic distortion which gives poor power quality. Lot of topologies has been developed to overcome the drawbacks of a two level inverter. These topologies include more number of switching devices which increases the design complexity and cost. The optimum design of inverter requires less number of switches with better quality in waveform. In this paper, a symmetrical five level and seven levels inverter configuration with simplified pulse width modulation technique is proposed. This proposed inverter requires less switches, less protection circuits along with low cost and size. The analysis of the inverter circuits is done by using Matlab/Simulink software. The synthesized staircase wave form is shown and total harmonic distortion (THD) is also measured.</p>

Design and Experimentation of Boost Cascaded DC Link Inverter for Domestic UPS Applications

2015 ◽  
Vol 24 (10) ◽  
pp. 1550156 ◽  
Author(s):  
R. Uthirasamy ◽  
U. S. Ragupathy
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Prototype Model ◽  
Ac Power ◽  
Power Spectral ◽  
Voltage Stress ◽  
Power Switches ◽  
Gate Driver ◽  
Cascaded Multilevel Inverter

A new structure of Boost Cascaded DC Link H-Bridge Inverter (BCDCLHBI) is proposed for domestic UPS applications. It consists of DC-DC converter, sub-multilevel modules and H-bridge inverter circuits. The proposed sub-multilevel modules synthesize a stepped DC link voltage with reduced voltage stress across the H-bridge inverter. Compared with conventional two-level inverter the proposed stepped DC link inverter configuration has reduced Power Spectral Density (PSD) and reduced voltage stress. Compared with conventional Cascaded Multilevel Inverter (CMLI) configuration, the proposed system has reduced power switches, DC sources and gate driver requirements. To obtain better quality of AC power output, carrier-level shifted Pulse Width Modulation (PWM) schemes are developed for sub-multilevel switching. A simulation and prototype model of 7-level BCDCLHBI is developed and its performance is validated.

Non-Isolated Bidirectional DC-DC Converter with Step up-down Capability Based on Energy Materials

2012 ◽  
Vol 459 ◽  
pp. 44-46
Author(s):  
Hyun Lark Do
Keyword(s):  
Steady State ◽  
Pulse Width ◽  
Power Flow ◽  
Pulse Width Modulation ◽  
Boost Converter ◽  
Experimental Results ◽  
Switching Frequency ◽  
Energy Materials ◽  
Steady State Analysis ◽  
Power Switches

A non-isolated bidirectional DC-DC cconverter with step up-down capability is proposed in this paper. The proposed converter operates with a fixed switching frequency and has a step up-down capability regardless of the direction of power flow. Voltage stresses of the power switches are lower than those in the conventional buck-boost converter. Moreover, only a single magnetic component is required in the proposed converter. An asymmetrical pulse width modulation (APWM) control shceme is utilized. The operation principle and steady-state analysis of the proposed converter are provided. A prototype of the proposed converter is developed, and its experimental results are presented for validation

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