scholarly journals An Enhanced Half-Quasi-Z-Source Inverter for Wind Energy Conversion System with D-PMSG

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yang Zhang ◽  
Zhun Cheng ◽  
Qing Chen ◽  
Qingmei Li
Keyword(s):  
Low Voltage ◽  
Sine Wave ◽  
Duty Ratio ◽  
Voltage Gain ◽  
Direct Drive ◽  
Current Harmonics ◽  
Stator Current ◽  
Large Distortion ◽  
Simulation And Experiment ◽  
Power Generation Systems

To solve the problem of the traditional quasi-Z-source inverters with low voltage gain, an enhanced half-quasi-Z-source inverter (E-HQZSI) is proposed and applied to direct-drive permanent-magnet wind power generation systems in this paper. The expression of the boosting factor is deduced, which shows that E-HQZSI has higher voltage gain compared with the QZSI and HQZSI. However, the higher voltage gain of the E-HQZSI will lead to the large distortion of the generator stator current necessarily. In this paper, a periodic shoot-through duty ratio control scheme is proposed to reduce the stator current harmonics for E-HQZSI. According to the change rule of the single-phase stator current, the shoot-through duty ratio is compromised to make that the three-phase stator currents are as close as possible to the sine wave. Finally, the correctness of the theoretical analysis is verified by simulation and experiment.

scholarly journals High Step-up Coupled Inductor Inverters Based on qSBIs

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 3032 ◽  
Author(s):  
Hongchen Liu ◽  
Xi Su ◽  
Junxiong Wang
Keyword(s):  
Steady State ◽  
High Voltage ◽  
Low Voltage ◽  
Duty Ratio ◽  
Voltage Gain ◽  
Passive Components ◽  
Steady State Analysis ◽  
High Voltage Gain ◽  
Voltage Stress ◽  
Working Principle

In this paper, two types of high step-up coupled inductor inverters based on qSBIs (quasi- switched boost inverters) are proposed. By applying the coupled inductor to the qSBIs, the voltage gain of the proposed inverter is regulated by turn ratio and duty ratio. Thus, a high voltage gain can be achieved without the circuits operating at the extreme duty cycle by choosing a suitable turn ratio of the coupled inductor. In addition, the proposed circuits have the characteristics of continuous input current and low voltage stress across the passive components. A boost unit can be added to the proposed inverters for further improvement of the voltage gain. In this paper, the working principle, steady state analysis, and the comparisons of the proposed inverter with other impedance-source inverters are described. A 200 W prototype was created and the experimental results confirm the correctness of the analysis in this paper.

scholarly journals Design of New High Step-Up DC-DC Converter Topology for Solar PV Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Shanthi Thangavelu ◽  
Prabha Umapathy
Keyword(s):  
Low Voltage ◽  
High Gain ◽  
Performance Comparison ◽  
Duty Ratio ◽  
Voltage Gain ◽  
Solar Pv ◽  
High Voltage Gain ◽  
Voltage Stress ◽  
Converter Topologies ◽  
Converter Topology

A new topology for high step-up nonisolated DC-DC converter for solar PV applications is presented in this paper. The proposed high-voltage gain converter topology has many advantages like low-voltage stress on the switches, high gain with low duty ratio, and a continuous input current. The analytical waveforms of the proposed converter are presented in continuous and discontinuous modes of operation. Voltage stress analysis is conducted. The voltage gain and efficiency of the converter in presence of parasitic elements are also derived. Performance comparison of the proposed high-gain converter topology with the recently reported high-gain converter topologies is presented. Validation of theoretical analysis is done through the test results obtained from the simulation of the proposed converter. For the maximum duty ratio of 80%, the output voltage of 670 V is observed, and the voltage gain obtained is 14. Comparison of theoretical and simulation results is presented which validates the performance of the proposed converter.

scholarly journals Coupled Inductor and Voltage Doubler Circuit for High Step-Up DC-DC Converter

2021 ◽  
Author(s):  
Abhinav Vinod Deshpande
Keyword(s):  
Steady State ◽  
Low Voltage ◽  
Research Paper ◽  
Duty Ratio ◽  
Voltage Gain ◽  
Steady State Analysis ◽  
Voltage Stress ◽  
Power Switches ◽  
Voltage Doubler ◽  
State Analysis

In this research paper, a novel high step up dc-dc converter with a coupled inductor and voltage doubler circuits is proposed. The converter achieves a high step up voltage gain with an appropriate duty ratio and low voltage stress on the power switches. Also, the energy which is stored in the leakage inductor of the coupled inductor can be recycled to the output. The operating principles and the steady state analysis of the proposed converter are discussed in detail. Finally, a prototype circuit of the proposed converter is implemented in the laboratory in order to verify the performance of the proposed converter.

scholarly journals An Impedance Network-Based Three Level Quasi Neutral Point Clamped Inverter with High Voltage Gain

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1261 ◽  
Author(s):  
Muhammad Aqeel Anwar ◽  
Ghulam Abbas ◽  
Irfan Khan ◽  
Ahmed Bilal Awan ◽  
Umar Farooq ◽  
...  
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Research Work ◽  
Current Source ◽  
Neutral Point ◽  
Voltage Source ◽  
Duty Ratio ◽  
Voltage Gain ◽  
High Voltage Gain ◽  
Source Current

Due to the impediments of voltage source inverter and current source inverter, Z-Source Inverter (ZSI) has become notorious for better power quality in low and medium power applications. Several modifications are proposed for impedance source in the form of Quasi Z-Source Inverter (QZSI) and Neutral Point Clamped Z-Source Inverter (NPCZSI). However, due to the discontinuity of the source current, NPCZSI is not suitable for some applications, i.e., fuel cell, UPS, and hybrid electric vehicles. Although in later advancements, source current becomes continuous in multilevel QZSI, low voltage gain, higher shoot-through duty ratio, lesser availability of modulation index, and higher voltage stress across switches are still an obstacle in NPCZSI. In this research work, a three-level high voltage gain Neutral Point Clamped Inverter (NPCI) that gives three-level AC output in a single stage, is proposed to boost up the DC voltage at the desired level. At the same time, it detains all the merits of previous topologies of three-level NPCZSI/QZSI. Simulations have been done in the MATLAB/Simulink environment to show the effectiveness of the proposed inverter topology.

scholarly journals The Power Losses in Cable Lines Supplying Nonlinear Loads

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1374
Author(s):  
Bartosz Rozegnał ◽  
Paweł Albrechtowicz ◽  
Dominik Mamcarz ◽  
Monika Rerak ◽  
Maciej Skaza
Keyword(s):  
Bessel Function ◽  
Cross Section ◽  
Power Loss ◽  
Sine Wave ◽  
Active Power ◽  
New Method ◽  
Power Losses ◽  
Nonlinear Loads ◽  
Current Harmonics ◽  
Cable Lines

This paper presents the skin effect impact on the active power losses in the sheathless single-core cables/wires supplying nonlinear loads. There are significant conductor losses when the current has a distorted waveform (e.g., the current supplying diode rectifiers). The authors present a new method for active power loss calculation. The obtained results have been compared to the IEC-60287-1-1:2006 + A1:2014 standard method and the method based on the Bessel function. For all methods, the active power loss results were convergent for small-cable cross-section areas. The proposed method gives smaller power loss values for these cable sizes than the IEC and Bessel function methods. For cable cross-section areas greater than 185 mm2, the obtained results were better than those for the other methods. There were also analyses of extra power losses for distorted currents compared to an ideal 50 Hz sine wave for all methods. The new method is based on the current penetration depth factor calculated for every considered current harmonics, which allows us to calculate the precise equivalent resistance for any cable size. This research is part of our work on a cable thermal analysis method that has been developed.

Cascaded Multilevel Inverter IM Speed-Sensorless Vector Control System Based on MRAS Theory

2013 ◽  
Vol 344 ◽  
pp. 159-163
Author(s):  
Zhen Jun Lin ◽  
Sheng Hua Huang
Keyword(s):  
Vector Control ◽  
Induction Motor ◽  
Low Voltage ◽  
Multilevel Inverter ◽  
Speed Sensorless ◽  
Multilevel Inverters ◽  
Sensorless Vector Control ◽  
Simulation And Experiment ◽  
Vector Control System ◽  
Cascaded Multilevel Inverter

Cascaded multilevel inverters could realize high-voltage output based on a series connection of power cells which use standard low-voltage component configurations. This characteristic could achieve high-quality output voltage waveforms and input current waveforms. These merits are made for motor control, especially in the field of speed-sensorless vector control of induction motor based on the theory of MRAS. This paper constructs a simulation system with the help of MATLB/SIMULINK and a system combined cascaded H-bridge multilevel inverter with induction motor with the help of DSP and FPGA. The simulation and experiment results verified the superiority of cascaded multilevel inverter applied on the MRAS speed-sensorless vector control of induction motor.

A High Step-up DC-DC Converter Based on the Voltage Lift Technique for Renewable Energy Applications

2021 ◽  
Vol 13 (19) ◽  
pp. 11059
Author(s):  
Shahrukh Khan ◽  
Arshad Mahmood ◽  
Mohammad Zaid ◽  
Mohd Tariq ◽  
Chang-Hua Lin ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Common Ground ◽  
Closed Loop ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Input Voltage ◽  
High Gain ◽  
Boost Converter ◽  
Open Loop ◽  
Voltage Gain

High gain DC-DC converters are getting popular due to the increased use of renewable energy sources (RESs). Common ground between the input and output, low voltage stress across power switches and high voltage gain at lower duty ratios are desirable features required in any high gain DC-DC converter. DC-DC converters are widely used in DC microgrids to supply power to meet local demands. In this work, a high step-up DC-DC converter is proposed based on the voltage lift (VL) technique using a single power switch. The proposed converter has a voltage gain greater than a traditional boost converter (TBC) and Traditional quadratic boost converter (TQBC). The effect of inductor parasitic resistances on the voltage gain of the converter is discussed. The losses occurring in various components are calculated using PLECS software. To confirm the performance of the converter, a hardware prototype of 200 W is developed in the laboratory. The simulation and hardware results are presented to determine the performance of the converter in both open-loop and closed-loop conditions. In closed-loop operation, a PI controller is used to maintain a constant output voltage when the load or input voltage is changed.

MULTI UNITS OF SINGLE PHASE DISTRIBUTED GENERATION COMBINED WITH BATTERY ENERGY STORAGE FOR PHASE POWER BALANCING IN DISTRIBUTION NETWORK

2016 ◽  
Vol 78 (10-4) ◽  
Author(s):  
Amirullah Amirullah ◽  
Mochamad Ashari ◽  
Ontoseno Penangsan ◽  
Adi Soeprijanto
Keyword(s):  
Energy Storage ◽  
Single Phase ◽  
Low Voltage ◽  
Distribution Network ◽  
Battery Energy Storage ◽  
Current Harmonics ◽  
Line Current ◽  
Distributed Generators ◽  
Distribution Line ◽  
Battery Energy

Randomly installed distributed generators (DGs) in households may cause unbalanced line current in a distribution network. This research presents a battery energy system for balancing of line current in a distribution network involving multi units of single phase photovoltaic (PV) distributed generators (DGs). In this paper, the PV generators were simulated consisting of a buck-boost DC/DC converter and single phase DC/AC inverter. It was connected to the distribution line through the low voltage 220 volt 50 Hz. The proposed phase balancing system uses battery energy storage and three single phase bidirectional inverters. The inverter is capable of injecting current or absorbing power from the line to the battery. This inverter operation is arranged to balance each distribution line separately, as well as to improve other power quality parameters, such as voltage and current harmonics. Simulation results show that the system was capable of improving the unbalanced line current from 15.59 % to 11, 48 % and unbalanced line voltage from 1.76 % to 0.58 %. The system was able for increasing current harmonics from 0.98 % to 1.03% and voltage harmonics from 38.96% to 39.08%.

scholarly journals Synchronized Control of Voltage and Current Harmonics in Distributed Generation System using Fuzzy Controller

2019 ◽  
Vol 8 (12) ◽  
pp. 1179-1182
Keyword(s):  
Distributed Generation ◽  
Energy Demand ◽  
Power Flow ◽  
Fuzzy Controller ◽  
Low Voltage ◽  
Load Condition ◽  
Control Technique ◽  
Current Harmonics ◽  
Simultaneous Control ◽  
Unbalanced Load

The worldwide energy demand is increasing due to increase in population and economic growth. The grid is gradually replaced by Distributed generation systems (DGs). Recently low voltage DG interfacing converter on the non linear load compensation is performed by unified power flow converter. The proposed control technique is analyzed for Simultaneous control of voltage and power under unbalanced load condition using MATLAB/SIMULINK software

scholarly journals Conversor Doubler Output Coupled Inductor para Aplicações de Fontes Alternativas

2021 ◽  
Author(s):  
HENRIQUE JAHNKE HOCH ◽  
TIAGO MIGUEL KLEIN FAISTEL ◽  
ADEMIR TOEBE ◽  
ANTóNIO MANUEL SANTOS SPENCER ANDRADE
Keyword(s):  
High Voltage ◽  
Duty Cycle ◽  
Low Voltage ◽  
Energy Generation ◽  
Boost Converter ◽  
Voltage Gain ◽  
Switched Capacitors ◽  
Number Of Components ◽  
Photovoltaic Energy ◽  
High Voltage Gain

High step-up DC-DC converters are necessary in photovoltaic energy generation, due the low voltage of the panels source. This article propose the Doubler Output Coupled Inductor converter. This converter is based in boost converter and utilize switched capacitors and a coupled inductor to maximize the static voltage gain. The converter achieve a high voltage gain with low turns ratio in the coupled inductor and an acceptable duty cycle. Can highlight the converter utilize low number of components and have low voltage and current stresses in semiconductors. To validate and evaluate the operation of the converter a 200W prototype is simulated.

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