scholarly journals High Performance DC-to-AC Converter Using Snubberless H-Bridge Power Switches and an Improved DC-to-DC Converter

2021 ◽  
Vol 15 ◽  
pp. 315-333
Author(s):  
Candidus U. Eya ◽  
Ayodeji Olalekan Salau ◽  
Stephen Ejiofor Oti
Keyword(s):  
High Performance ◽  
Harmonic Distortion ◽  
Control Unit ◽  
Input Voltage ◽  
Storage Capacitor ◽  
Small Scale ◽  
Two Stage ◽  
Dc Power ◽  
Power Switches ◽  
And Control

This paper presents the analysis, modeling, simulation, and implementation of a high performance DC-to-AC (DC-AC) converter. The system comprises of a combination of DC power source, stress less DC-to-DC (DC-DC) voltage converter, two snubberless power switches, and control unit. The system is portable, has a two-stage input voltage transformation and amplification with no transformer and occupies less space unlike the classical two-stage inverter systems. In addition, the system produces a constant DC boosted voltage with less stress on both the source and DC storage capacitor which are not found in conventional converters. The proposed power electronic converter system produced the following results: pure sine voltage and current waveforms, total harmonic distortion (THD) of 4.294%, power output of 5740W, efficiency of 98.9%, power loss of 60W and fast dynamic response. The target areas of applications of the proposed converter are in medium and small scale industries.

scholarly journals Improved Modulated Carrier Controlled PFC Boost Converter Using Charge Current Sensing Method

Energies ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 717 ◽  
Author(s):  
Jintae Kim ◽  
Chung-Yuen Won
Keyword(s):  
Control Method ◽  
Harmonic Distortion ◽  
Control Unit ◽  
Input Voltage ◽  
Boost Converter ◽  
Current Sensing ◽  
Voltage Range ◽  
Zero Current ◽  
Voltage Amplifier ◽  
Current Duration

An improved modulated carrier control (MCC) method is proposed to offer high power factor (PF) and low total harmonic distortion (THD) at a wide input voltage range and load variation. The conventional MCC method not only requires a multiplier and divider, but also is hard to be implemented with a micro controller unit without a high frequency oscillator. To overcome the problem and maintain the advantages of the conventional MCC method, the proposed MCC method adopts a current integrator, an output voltage amplifier, a zero-current duration (ZCD) demodulator of the boost inductor, and a carrier generator. Thus, it can remove a multiplier and well, as it allows for being operable with a general micro control unit. This paper presents an operation principle of the proposed control method. To verify the proposed control method, experimental results with 400 W PFC boost converter is demonstrated.

Modified MPC based grid-connected five-level inverter for photovoltaic applications

2018 ◽  
Vol 37 (2) ◽  
pp. 971-985 ◽  
Author(s):  
Mohammad Maalandish ◽  
Seyed Hossein Hosseini ◽  
Mehran Sabahi ◽  
Pouyan Asgharian
Keyword(s):  
Control Method ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Modified Model ◽  
Content Type ◽  
Current Path ◽  
Voltage Stress ◽  
Photovoltaic Applications ◽  
Multi Level ◽  
And Control

PurposeThe main purpose of this paper is to select appropriate voltage vectors in the switching techniques and, by selecting the proper voltage vectors, be able to achieve a DC link with the same outputs and a symmetric multi-level inverter. Design/methodology/approachThe proposed structure, a two-stage DC–AC symmetric multi-level inverter with modified Model Predictive Control (MMPC) method, is presented for Photovoltaic (PV) applications. The voltage of DC-link capacitors of the boost converter is controlled by MMPC control method to select appropriate switching vectors for the multi-level inverter. The proposed structure is provided for single-phase power system, which increases 65 V input voltage to 220 V/50 Hz output voltage, with 400 V DC link. Simulation results of proposed structure with MMPC method are carried out by PSCAD/EMTDC software. FindingsBased on the proposed structure and control method, total harmonic distortion (THD) reduces, which leads to lower power losses and higher circuit reliability. In addition, reducing the number of active switches in current path causes to lower voltage stress on the switches, lower PV leakage current and higher overall efficiency. Originality/valueIn the proposed structure, a new control method is presented that can make a symmetric five-level voltage with lower THD by selecting proper switching for PV applications.

scholarly journals Simulation of Single Phase Switching Capacitor 49 Level Inverter with Reduced THD

2019 ◽  
Vol 8 (6) ◽  
pp. 837-841
Keyword(s):  
Power Supply ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Matlab Simulation ◽  
Phase Switching ◽  
Dc Voltage ◽  
Dc Power ◽  
Power Switches ◽  
Multi Level ◽  
Switched Capacitor Converter

The study of single phase Switched Capacitors Multi Level Inverter (MLI) is used with Switched Capacitor Converter (SCC) units. The SCC is used to increase the input DC voltage by connecting capacitor in string and shunt. This increassed DC link voltage is converted in to multilevel i.e. 49 level AC output. This SCMLI topology is used to reduce the number of switches, diodes, isolated dc power supply and Total Harmonic Distortion (THD). The SCMLI provides 49 level output voltage using 14 power switches and 3 isolated power supply. The performance of the SCMLI topology is confirmed by using MATLAB simulation result

scholarly journals Process Automation of Demineralization Plant using Delta PLC, Wonderware Intouch and Delta HMI

2019 ◽  
Vol 8 (3) ◽  
pp. 4721-4727
Keyword(s):  
Control Unit ◽  
Cost Effective ◽  
Small Scale ◽  
Centralized Control ◽  
Monitoring And Control ◽  
Process Automation ◽  
Demineralized Water ◽  
Small Scale Industry ◽  
And Control

The proposed project is to design a commercial Programming Logic Controller based automation unit with SCADA and HMI for Demineralization Unit. In Demineralization, the raw water obtained from underground and Lake is treated to meet standard as per usage. Some of the closely monitored are pH, turbidity, etc. The automation tool designed uses DELTA PLC which is interfaced to local HMI which is in-turn connected to Wi–Fi using TP– Link thus supporting Remote Monitoring and Control. For centralized control unit SCADA is used by interfacing PLC with Computer. To match the communication protocol between PLC and SCADA, OPC software called KEPServer is used. Significant improvement in quantity and quality of demineralized water can be achieved. The proposed design is cost effective as it suit for small scale industry

scholarly journals Removal of Pathogens from Domestic Wastewater Using Small-Scale Gradual Hydroponics Planted with Duranta erecta, Addis Ababa, Ethiopia

2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Solomon Tibebu ◽  
Abebe Worku ◽  
Kenatu Angassa
Keyword(s):  
Heterotrophic Bacteria ◽  
Addis Ababa ◽  
Control Unit ◽  
Domestic Wastewater ◽  
Experimental Unit ◽  
Small Scale ◽  
Hydroponic System ◽  
Control Units ◽  
Significant Difference ◽  
And Control

This study aimed to evaluate the treatment potential of gradual hydroponics planted with Duranta erecta in the removal of pathogens from domestic wastewater. Two experimental and control units were configured in series. Each unit contains three bioreactors and was arranged in a cascaded configuration. The two experimental units used both plant and media, but the two control units used only media to treat the wastewater. Gravel and polyester sponge were used as media. Experimental unit 1 and control unit 1 used gravel as media; however, experimental unit 2 and control unit 2 used polyester sponges as media. The experiment was operated at hydraulic retention times of 1, 3, 5, and 7 days in a continuous mode. The performance of the hydroponic system was evaluated by characterizing the influent and effluent quality using standard methods. At optimum hydraulic retention time (7 days), the average removal of experimental units 1 and 2 was 98.7% and 89.8% for heterotrophic bacteria, 96.2% and 86.8% for total coliform, and 92.9% and 84.0% for fecal coliform, respectively. Analysis of variance showed that there was a significant difference P < 0.05 between the two experimental and control units in removing pathogens, but no significant difference P > 0.05 was observed between the two experimental units and between the two control units. Heterotrophic bacteria and coliforms were satisfactorily removed from domestic wastewater via a gradual hydroponic system. Hence, the hydroponic treatment system planted with Duranta erecta has a promising potential in the removal of pathogens from domestic wastewater in developing countries including Ethiopia.

scholarly journals Controlled Intersystem Link Based on a "Hexagon" Scheme Converter

2021 ◽  
Author(s):  
Lev Kalinin ◽  
◽  
Dmitrii Zaitsev ◽  
Mihai Tirshu ◽  
Irina Golub ◽  
...  
Keyword(s):  
Power Systems ◽  
Control Strategy ◽  
Frequency Conversion ◽  
Frequency Converter ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Technical Solution ◽  
Operating Characteristics ◽  
Fine Control ◽  
And Control

The aim of the paper is to research possibility to use a "hexagon" scheme static frequency converter as controlled intersystem link for two parallel operating power systems with different operating frequencies, or standards for frequency stabilization. The paper aims to study the transformer device operating characteristics that implements the output voltage phase circular rotation principle relative to the input voltage and controlled by power electronics. This goal is achieved through the elaborated "rough" device control strategy, which made it possible to provide controlled AC intersystem link of asynchronous power systems without the use of additional harmonic filters and dampers. Two sectioning modes of adjusting windings were used to apply 24 and 48 position laws of the converter "fine" control. The most significant results are the new technical solution of the frequency converter, as well as the "rough" control strategy. To assess the conversion quality, indicators were used that characterize the degree of stability of the transmitted power and the harmonic distortion of the current. The computational experiments results have shown the effectiveness of the proposed "rough" control strategy. It is proved that 48-position sectioning of the "fine" regulation winding can significantly improve the quality of conversion compare to 24-position. The obtained results significance is that developed technical solution provides acceptable indicators of the frequency conversion quality and transmitted active power stability. In addition, the use of the proposed converter technical solution can significantly reduce the number of windings and control means compare to previously ones studied by the authors

REDUCTION OF CURRENT AND VOLTAGE STRESSES IN SINGLE-STAGE AC/DC POWER FACTOR CORRECTION CONVERTERS WITH REDUCED REPEATED POWER PROCESSING AND INHERENT INPUT CURRENT CONTROL

2004 ◽  
Vol 13 (03) ◽  
pp. 535-555 ◽  
Author(s):  
DYLAN DAH-CHUAN LU ◽  
DAVID KI-WAI CHENG ◽  
YIM-SHU LEE
Keyword(s):  
Power Factor ◽  
Power Factor Correction ◽  
Input Power ◽  
Current Control ◽  
Single Stage ◽  
Input Current ◽  
Storage Capacitor ◽  
New Family ◽  
Dc Power ◽  
Power Switches

In this paper, a new family of single-stage AC/DC power factor correction converters (S2PFCC), which possesses reduced voltage stress across the storage capacitor and no extra current stress on the power switch, is proposed. The converters are realized by reduced repeated power processing concept in which part of the input power is transferred to the load directly after the first power process. This results in lower storage capacitor voltage than that of previously developed S2PFCCs but maintaining high power factor. In addition, the inherent input current control allows the load current to reduce the input line current automatically when the load becomes light, preventing excessive amount of energy being stored in the storage capacitor. Although the proposed converters employed two power switches, a simple single-loop controller for the proposed S2PFCC to achieve power factor correction (PFC) and tight output regulation is also proposed. Experimental results are reported to verify the operation and concept of the new S2PFCC.

Research on Modeling and Control Strategy for Two-Stage Photovoltaic Grid-Connected System

2014 ◽  
Vol 1008-1009 ◽  
pp. 16-21
Author(s):  
Xia Dong ◽  
Li Na Zhang ◽  
Yu Ying Fu ◽  
Cui Lian Ji
Keyword(s):  
Control Strategy ◽  
High Performance ◽  
Dynamic Performance ◽  
Mathematic Model ◽  
Two Stage ◽  
Lcl Filter ◽  
Modeling And Control ◽  
Point Tracking ◽  
Power Point ◽  
And Control

This paper has built the mathematic model of the single-phase two-stage photovoltaic(PV) grid-connected system. The model consists of a boost DC/DC converter and a DC/AC inverter with LCL filter. On the basis of the variable step perturbation and observation method(P&O), the boost converter changes the output voltage of the PV array by adjusting the duty cycle to realize the PV maximum power point tracking(MPPT). The inverter system restrains the voltage fluctuation effectively by using feed-forward of the grid voltage and current tracking control technology, which has the high performance in both sinusoidal reference tracking and disturbance rejection. LCL filter improves the dynamic performance and restrains the high harmonics efficiently. The simulation with Matlab soft confirms the effectiveness of the model and control strategy.

scholarly journals Input switched closed-loop single phase SEPIC controlled rectifier with improved performances

2021 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Md. Shamsul Arifin ◽  
Mohammad Jahangir Alam
Keyword(s):  
Power Factor ◽  
Closed Loop ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Input Power ◽  
Open Loop ◽  
Dc Power ◽  
Wide Range ◽  
Input Side ◽  
Flow Through

DC power supply has become the driving source for some essential modern applications. Thereby, DC power conditioning has become a significant issue for engineers. Typically used rectifiers associated with a bridge structure is nonlinear in nature. Thereby, the current at input side of the rectifier contains harmonics, which also flow through the power line. The presence of harmonics causes several interruptions and reduce power quality. In this regard, a new close loop SEPIC controlled rectifier is proposed in this paper. The conventional scheme is arranged with a rectifier connected to a DC-DC converter, which is an open loop system. Consequently, such system cannot regulate voltage at load varying condition. The proposed SEPIC controlled rectifier can regulate voltage under load varying condition for a wide range. Additionally, the performance in terms of total harmonic distortion (THD) of input current and power factor at AC side are also within satisfactory range for the closed loop configuration. The controlled rectifier has four operating phases associated with switching states and input voltage polarity. The close loop configuration also incorporates a current and a voltage loop at the feedback path. The comparative studies have been performed among the proposed closed loop construction, the open-loop structure as well as the conventional construction. The effectiveness of the proposed controlled rectifier is verified in terms of THD and input power factor considering the results obtained from simulation.

scholarly journals Hybrid Resonant Converter with Three Half-Bridge Legs for Wide Voltage Operation

2019 ◽  
Vol 10 (1) ◽  
pp. 310 ◽  
Author(s):  
Bor-Ren Lin ◽  
Yong-Sheng Zhuang
Keyword(s):  
Power Conversion ◽  
Input Voltage ◽  
Resonant Circuit ◽  
Resonant Converters ◽  
Resonant Converter ◽  
High Input ◽  
Switching Operation ◽  
Voltage Range ◽  
Dc Power ◽  
Power Switches

This paper studied a hybrid resonant converter with three half bridge legs for wide input voltage operation. Compared to the conventional resonant converters with narrow voltage operation, the presented converter can achieve wider voltage operation. On the basis of the proper switching status of power switches, the developed converter can operate at half-bridge resonant circuit under high input voltage range and the other two full-bridge resonant circuits under medium and low input voltage ranges. Each resonant circuit has a 2:1 (Vin,max = 2Vin,min) input voltage operation range. Therefore, the developed converter can achieve an 8:1 (Vin,max = 8Vin,min) wide voltage operation. The main advantage of the studied converter is the single-stage direct current (DC)/DC power conversion instead of the two-stage power conversion to achieve wide voltage operation. Because the equivalent resonant tank of the adopted converter is controlled by frequency modulation, the soft switching operation on power switches or rectifier diodes can be realized to improve circuit efficiency. The performance of the proposed circuit was confirmed and verified by experiments with a laboratory circuit.

Sign in / Sign up

Export Citation Format

Share Document