Inverter Type Research Articles

Power Quality Enhancement in Grid-Connected Solar PV Systems Using Adaptive Control and Multilevel Inverter Topologies Under Dynamic Grid Conditions

This paper introduces a control strategy that uses an integrator-based positive sequence estimator to improve the power quality of a grid-connected double-stage solar PV system. The control extracts positive sequence components from distorted and unbalanced grid voltages to calculate unit templates and grid reference currents during grid anomalies like distortion, unbalance, sag/swell, and DC offset. A feedforward term is introduced to the photovoltaic array to ensure rapid transient response, and the DC-link voltage is adaptively regulated to reduce the voltage source converter (VSC) losses during weak grid conditions. The paper compares the performance of two-level and three-level inverters in this system configuration, highlighting the differences in power quality improvement, harmonic reduction, and system efficiency under various grid disturbances and intermittent solar conditions. Simulation results, performed in MATLAB, validate the superior performance of the three-level inverter in terms of lower total harmonic distortion (THD) in grid currents, in compliance with IEEE standard 519, while demonstrating the satisfactory response of both inverter types during challenging grid conditions like intermittent solar irradiation, DC offset, voltage distortions, unbalance, and voltage sag/swell.

A 31 L multilevel inverter topology with less switching devices for hybrid electric vehicle applications

In this article, a 12 switch 31 L multi-level inverter (MLI) is proposed with the benefits of least switching devices for electric vehicle applications. In most electric vehicles (EV), conventional inverters are utilized so the lifetime of electric vehicle induction motors is reduced due to the high THD level and high voltage stress. To rectify this, a new inverter topology is proposed with minimum switching devices by increasing the level to 31, and also the THD should be maintained within IEEE standards. This inverter topology is constructed with variable DC sources (PV system) along with required capacitors and a polarity changer. The specific feature of this topology is that it can generate any level of voltage with minimum switching devices, less voltage stress, minimum THD, and less cost are tabulated in the comparison. This type of inverter can also applicable for high voltage (HV) applications and grid-connected systems. Furthermore, the proposed topology is simulated with MATLAB software and the downscale prototype model is developed using the DSPIC30f2010 controller.

Analisis Potensi Daya Listrik PLTS Atap di Gedung K4 Universitas Negeri Surabaya

In order to utilize the potential of solar energy and support the government in its energy transition efforts and achieve Net Zero Emissions, it is necessary to utilize solar power plants more massively. One thing that can be done is the installation of solar panels on the roof of a building called Rooftop PLTS. This rooftop PLTS is designed on the roof of the K4 Unesa building with an ongrid system because lecture activities only exist from morning to evening. Research conducted to analyze the potential of electrical energy on the roof of the K4 building using OpenSolar software. From the simulation results, the roof of the K4 building can be designed to install 70 solar panels with the LR4-72HPH-450M type and 5 Goodwe GW5K-DT type inverters which can produce 35,478 kWh per year with a PLTS capacity of 31,500 Wp. From the shadow simulation results, it is found that the selected location is optimal because there are no shadows of other buildings, trees or shadows from the solar panels themselves. Then from the POA analysis, it is found that between April to September has a relatively large amount of generation while in February the lowest energy is generated.

Comparison between Cascaded H-Bridge and Neutral Point Clamped Topologies in Medium-Voltage Systems

Medium voltage motor drives (MVD) come in various topologies that allow designers to choose the best option for their application based on technical and economic considerations. The Neutral Point Clamped (NPC) and Cascade H-Bridge (CHB) are the most particular topologies that have come to the fore. CHB and NPC MVD's primary operating principles, switching stress, topological complexity, and harmonic distortion of the inverter output will be presented in this article, along with a brief review of suitable modules. Even though the number of parts in a cascaded inverter is lower than that of a neutral point-clamped inverter, it has been demonstrated that the stress on the switches in both types of inverters is the same and that the resulting output waveforms are nearly identical in terms of harmonic distortion. The neutral point clamped topology requires less secondary winding from the transformer, fewer voltage-balancing capacitors, the same quantity of switches, and extra clamping diodes. Benefits of NPC include high-power-density inverters, enhanced output quality, reduced number of components, reduced heat losses, increased efficiency, elimination of commonmode voltages and currents thanks to an isolation transformer, and a remote transformer that allows for a more adaptable footprint. Additionally, the NPC drive rectifier system (Transformer and diode H-bridges) has the advantage of more simplicity, ease of assembly, fewer connections, fewer space requirements, and an expensive isolation transformer. The MATLAB simulation for both topologies was carried out, with 3 phase motor 3.8kV, 150 KW motor parameters.

A Non-Linear Control Technique for Single Phase qZSI

Quasi-Z-source inverters, or qZSIs, are a common type of inverter used in transformer-less systems because they can boost or buck input voltage without a requirement for a DC- DC converter. A transformer is not necessary for the qZSI's single-stage conversion to operate as a grid-tie converter. In transformer-less designs common mode current is the major problem, though, because there is no galvanic isolation. To reduce the common mode current, this article offers controlling the qZSI using a modified pulse width modulation (PWM) approach two additional semiconductor switches. The developed methodology provides a practical means of integrating solar photovoltaic systems into the grid. what the recommended topology's attributes should be: 1)It uses the phase-leg shoot through to boost the direct current and voltage to required level by eliminating the need for a second dc-dc converter. 2) Freewheeling is achieved while removing PWM deadtime by employing extra linked switches.

Performance Investigation of 17 Level Reduced Switch Count Multilevel Inverter

The primary objective of this paper is to introduce a 17-level multilevel inverter with only eight power switches and three diodes that can be suitable for electric vehicle applications. This setup utilizes three distinct unequal DC sources to create the 17 levels of output voltage waveforms. The modes of operations of the proposed topology have been discussed in detail. The calculation of conduction losses, switching losses, efficiency, total standing voltage, and cost function per level for the suggested inverter has been elaborated. Due to more semiconductor power switches, diodes, capacitors, driver circuits, and DC sources in typical inverters, switching losses, costs, and harmonic distortion are increased. The nearest-level control technique has been utilized to control the switching elements of the recommended configuration. The performance comparison of various multilevel inverter topologies has also been discussed. The suggested multilevel inverter provides a higher efficiency of 98.60%, cost function of 3.6 for a weight coefficient of 1, improved power quality, and higher reliability. A reduction in the power switches significantly reduces the convolution of switching circuitry. The total harmonic distortion produced by this inverter is 3.49%, which comes under the IEEE standard of 5%.

ADRC-LSE Control of a Dual-Star Induction Motor Powered by a Dual 3-level NPC Inverter

In the context of electric vehicle propulsion drives, this paper presents anActive disturbances Rejection Control (ADRC) strategyapplied to a Dual Star Induction Motor (DSIM)powered by dual 3 levels inverter type NPC. The proposed method focuses on enhancing the Active Disturbance Rejection Control (ADRC) method by integrating Least Squares Estimation, establishing a direct relationship between the control law and the necessary frequency for the DSIM to turn in the exact speed whatever the load torque applied. The ADRC with Least Squares Estimation is compared with Field-Oriented Control (FOC) to evaluate their performance in tracking reference speed and stabilizing time. Additionally, another test is conducted to assess the ADRC's ability to reject disturbances. Results from the simulation demonstrate the effectiveness of ADRC with Least Squares Estimation, showcasing its potential for optimizing DSIM control in electric vehicle applications, thereby contributing to enhanced efficiency and stability.

Multifunctional application of planar 2D molecule for light-emitting heterostructures

The object of research is the donor-acceptor compound, organic and hybrid heterostructures based on it. The paper is focused on a comprehensive approach to solving the problem of the efficiency of light-emitting devices, finding new technological and design solutions for the use of organic compounds as multifunctional materials for various types of light-emitting devices. The paper presents the multifunctional application of a planar 2D molecule as an emission layer for typical and inverted types of light-emitting heterostructures, as well as a matrix for a host-guest system using inorganic quantum dots. The developed light-emitting structures are characterized by external quantum efficiency typical for fluorescent devices, but good stability over the entire length of the consumption voltage. QLED brightness is 1600 cd·m-2 and EQE 1.4 %, which are good parameters for use in display technology. Organic LEDs based on planar molecules are promising candidates for use in modern lighting systems. A separate advantage of these light-emitting structures is the multifunctionality of using one compound for different types of light-emitting structures, including inverted heterostructures. Special attention is paid to the technological and design implementation of invert structures, since their geometry allows direct connection to the back board of the n-channel transistor on the substrate. In addition, organic LEDs have low energy consumption and are environmentally friendly due to the absence of toxic substances in their architecture, which creates the prerequisites for saving energy resources and reducing the industrial burden on the environment.

Nonlinear control of three level NPC inverter used in PV/grid system: comparison of topologies and control methods

With the passage of time, the importance of using renewable energy systems to overcome energy consumption and improve the quality of the grid has emerged through the use of nonlinear control techniques and reliance on advanced types of inverters such as multi-level inverters. This research is focused on comparing two grid-connected converter topologies in a photovoltaic (PV) generation system connected to a three-phase grid that serves a non-linear load. Additionally, the study explores two different control techniques applied to this converter, evaluating their effects on the total harmonic distortion coefficient. A comparison has been made between the traditional inverter and the three-level inverter type neutral point clamped (NPC) inverter, with the use of integral backstepping (IBS) technique which was also compared with the proportional integral (PI) controller. The simulation results in MATLAB/Simulink are presented illustrating the performances and the strong effectiveness of the three-level NPC inverter controlled by the proposed technique (IBS).

A Study on Droop and VOC Methods

Grid-forming and grid-following inverters play crucial roles in modern power systems, each with distinct functionalities and advantages. This research paper aims to offer a thorough comparative analysis of these two inverter types, concentrating particularly on two grid-following methods: Droop and VOC. The paper explores the principles, merits, and demerits of each method and compares simulation results to assess their performance under overload conditions. The findings contribute to a deeper understanding of inverter technologies and inform decision-making in power system design and implementation.

Power Flow Analysis Using Fuzzy for Single Phase Transformer Less PV System Connected with a Nine-Level Converter

Power electronics technology advancements and growing environmental concerns worldwide have made photovoltaic (PV) systems more visible in distributed generation systems. Photovoltaics, or solar PV, is an important component of solar energy for generating electricity. Grid-connected inverters must be able to regulate the amount of power they inject into the grid, track maximum power points, be highly efficient, and inject currents into the grid with minimal harmonic distortion. Two step-down converters were used to construct an inverter without a single-phase transformer. This study investigates two multi-sequence inverter types that use different voltages and are based on single-phase grid-connected photovoltaic (PV) technology. A new nine-level grid-connected transformer-less photovoltaic converter was proposed in this study. MATLAB was used to construct the complicated FFT simulation using fuzzy logic controls. Analyzing efficiency through simulation in order to enhance efficiency. This work aims to replace PI controllers with fuzzy controlled systems so that single-stage operation can be improved with reduced switches in an economic manner. An improvement of 10% over the existing system is achieved by implementing fuzzy computing.

A seven‐level switched‐capacitor based transformerless inverter with modified PWM strategy to enhance the performance of grid‐connected PV systems

AbstractAmong different types of transformerless photovoltaic inverters, multi‐level inverters based on switched‐capacitors (SC) are the burning topic of recent decades due to their potential advantages, such as, single source requirement, voltage boosting capability, and high power density. However, for a seven level output voltage, a conventional SC based inverter architecture uses more than two units of SC, a large amount of power switches, which then lead to capacitor voltage balancing problems. This paper presents a seven‐level switched‐capacitor transformerless inverter (SCTI), which is structured with only two SC units, ten power switches, and a single DC source. The proposed SCTI ensures voltage boosting capability, self‐voltage balancing, and low power semiconductor losses. Apart from these, a modified sinusoidal pulse width modulation (MSPWM) is also proposed in this work, which guarantees better thermal performance and low inverter output voltage THD for the proposed SCTI. The proposed SCTI along with the MSPWM is simulated in MATLAB/Simulink and PLECS computer simulation environments. A reduced scale laboratory prototype is also built and tested to ensure the feasibility of the proposed SCTI.

Interface texturing for enhanced PEDOT:PSS/si solar cell efficiency

Solar cell heterostructures based on PEDOT:PSS/Si heterojunction with a flat and microrelief interfaces of pyramidal and inverted pyramids type, unmodified and chemically doped PEDOT:PSS films have been fabricated. The maximum efficiency of 6.14% was obtained for solar cell heterostructures with a pyramidal type interface and doped PEDOT:PSS film, which is five times higher than for structure with a flat interface. It shown that an increase in the efficiency is occurred both due to decrease in optical losses from textured Si interface and improvement of electrical parameters of the polymer layer due to chemical doping with DMSO.

Fully active and highly reliable combined ring voltage controlled CMOS oscillator

Leveraging two types of enhanced delay stages to form an oscillation loop, results in a highly reliable CMOS ring oscillator versus external interventions. The idea is investigated via symbolic delay calculations and the HSPICE circuit simulator while 0.18 μm CMOS is exploited. Based on two described inverters, three-ring oscillators are presented. The two ones use only one type of delay stage while the third is combined using two basic inverters and a single current-starved inverter. The basic type inverter is the fastest while is sensitive to power supply and temperature variations. On the other hand, the sensitivity of the current starved inverter is acceptable but this delay stage shows a large delay time, reducing oscillation frequency. This work tries to address this tradeoff between speed and sensitivity by proposing an oscillation loop. The delay times analysis and simulation results verify the robust performance of the proposed oscillator.

Intelligent Adaptation Mechanism of Full-Order Luenberger Observer based on Fuzzy Logic Applied to Direct Control by Flux Orientation without Speed Sensor for Doubly Fed Induction Motor

The present work focused on the control by flow orientation without mechanical sensors on the doubly fed induction motor by the use of artificial intelligence techniques. Our main contribution lies in the development of control methodologies to improve control by flux orientation, for this, we acted on the type and control of inverters by the use of multilevel inverters and then on the observation technique of rotor speed based on the high gain Luenberger observer and improvements to the speed adaptation mechanism using fuzzy logic. Simulation tests of the proposed improvement approach were carried out at the end of this work to verify the behavior of this system in the face of different types of training.

The Effect of Pyramid and Reverse Pyramid Loadings on Spine and Pelvis Coordination Variability During Squat

Background and Aims Pyramid and reverse pyramid loading patterns are used to increase the training load in resistance training. Although physiological studies have attempted to compare the two patterns, the difference between the two loading patterns on the biomechanics of the spine and pelvis has not been determined. This study aimed to investigate the effect of pyramid and inverted pyramid loadings on spinal and pelvic coordination variability in squat movement. Methods Twelve bodybuilding athletes in Tehran City, Iran, voluntarily participated in this study. The subjects performed squat movements as the pyramid and reverse pyramid at intensities of 50%, 70%, and 90% of ten maximum repetitions. Then, the kinematic information of the three segments of their spine and pelvis was recorded. Coordination and variability coordination were calculated using a modified vector coding method. Results The results of repeated measures analysis of variance showed a significant difference in the coordination pattern for pelvic-lower back coordination, lower-back to lower-trunk spine, and lower-trunk-to-upper-trunk spine in the intensity of 50%. A significant difference was observed in the coordination pattern, with an intensity of 70% for the lower back and lower trunk spine. Also, no statistical significance was observed between the pyramidal and inverted pyramidal loading types for spine and pelvis coordination. Conclusion According to the results of increasing the load in pyramid loading and decreasing the load in reverse loading, the coordination of distal couplings affected the sagittal plane more than the proximal one. It is recommended to use the reverse pyramid method for exercises and be more careful when performing pyramid exercises.

1- Dual Boost ANPC Type Inverter Topology With High Voltage Gain

1- Dual Boost ANPC Type Inverter Topology With High Voltage Gain

Two Types of Asymmetric Switched-Capacitor Five-Level Single-Phase DC-AC Inverters for Renewable Energy Applications

Two types of asymmetric switched-capacitor five-level single-phase DC-AC inverters are presented based on the clamping half-bridge circuit and the output half-bridge circuit. Furthermore, the switches of the two proposed circuits can be driven by half-bridge gate drivers and can be modularized. Moreover, the detailed analysis of the operation principle, design of clamping capacitor and output filter of these two inverters are presented. Finally, the feasibility and validity of the proposed structures are verified by PSIM-simulated results and experimental results using FPGA as the control kernel, respectively.

Improved Switching Performance in T Type Inverters for High Voltage Induction Motor Application

Improved Switching Performance in T Type Inverters for High Voltage Induction Motor Application

Rancang Bangun Multilevel Inverter dengan Filter Pasif L-C-L dan Teknologi IoT Untuk Memantau Perubahan Kecepatan Motor Induksi Satu Fasa

Multilevel inverter is a type of inverter used to generate AC signals with adjustable frequency and better quality. L-C-L passive filter is used to eliminate harmonic distortion in the generated AC signals. Meanwhile, IoT technology is used to remotely monitor and control the speed of the motor through a mobile application. In this thesis, the design of a flying capacitor multilevel inverter is used as an induction motor speed controller with the resulting Total Harmonic Distortion (THD) can be reduced if you add a level to the inverter. Then, L-C-L passive filter is designed to eliminate harmonic distortion in the generated AC signals. Furthermore, the implementation of IoT technology is carried out using Blynk IoT platform. The test results show that the multilevel inverter with L-C-L passive filter successfully generates AC signals with better quality compare without L-C-L passife filter. In addition, IoT technology is successfully implemented and allows users to remotely monitor and control the speed of the motor through a mobile application. Thus, the use of multilevel inverter with L-C-L passive filter and IoT technology can effectively increase the efficiency and control of single-phase induction motor.
 Keywords: multilevel inverter, L-C-L passive filter, IoT, induction motor, total harmonic distortion.