The Complete Production Process of Winded Soft-Pack Lithium-ion Batteries

 

This article details the complete production process of wound soft-pack lithium-ion batteries, from positive and negative electrode material coating, winding, tab welding, calendering and slitting, assembly and testing.

[Expert Report] Ding Lei, Shandong University: A Re-understanding of Power System Inertia

 

ELETRÔNICA DE POTÊNCIA-Retificador meia onda controlado a tiristor (RL)

 

Power Electronics in Renewable Energy Systems Suntio, Teuvo; Messo, Tuomas

 

ABSTRACT .The observed changes in weather conditions have accelerated the installation of renewable energy-based electricity systems around the world. Large-scale utilization of renewable energy sources in electricity production requires the use of power electronic converters to integrate the renewable energy systems into the power grids. This integration brings about certain challenges in terms of stability and robust performance of the power grids, which have to be solved before the wellbeing of the power grids can be guaranteed. This Special Issue of Energies aims to reveal the state-of-art in addressing interfacing problematics. According to the published papers, clear advancements have taken place, but the most critical issues remain unsolved. Direct power control with self-synchronizing synchronverters may be the most promising technique for solving the main stability problem, although many unsolved problems still persist. Another challenge in renewable energy production is the fluctuating nature of the available energy in renewable energy sources, which require utilization of stored energy to smooth the fluctuations. Different storage battery technologies are available, but their production may pose problems in the long term.

 ORIGINAL LINK:https://trepo.tuni.fi/handle/10024/225285

Dynamic Characteristics of Grid-Connected Three-Phase Z-Source Inverter in Photovoltaic Applications-Tampere University of Technology-Author Juha Jokipii

 Juha Jokipii Dynamic

 Characteristics of Grid-Connected Three-Phase Z-Source Inverter in Photovoltaic Applications

 Thesis for the degree of Doctor of Science in Technology to be presented with due permission for public examination and criticism in Festia Building, Auditorium Pieni Sali 1, at Tampere University of Technology, on the 15th of April 2016, at 12 noon.

ABSTRACT

 Due to the inevitable depletion of fossil fuels and increased awareness of their harmful environmental effects, the world energy sector has been moving towards extensive use of renewable energy resources, such as solar energy. In solar photovoltaic power generation, the needed interface between the source of electrical energy, i.e., a photovoltaic generator, and electrical energy transmission and distribution systems is provided by power electronic converters known as inverters. One of the latest addition into the large group of inverter topologies is a Z-source inverter (ZSI), whose suitability for different applications have been extensively studied since its introduction in 2002. This thesis addresses the dynamic characteristics of a three-phase grid-connected Z-source inverter when applied to interfacing of photovoltaic generators. Photovoltaic generators have been shown to affect the behavior of the interfacing power converters but these issues have not been studied in detail thus far in case of ZSI.

In this thesis, a consistent method for modeling a three-phase grid-connected photovoltaic ZSI was developed by deriving an accurate small-signal model, which was verified by simulations and experimental measurements by means of a small-scale laboratory prototype inverter. According to the results presented in this thesis, the small-signal characteristics of a photovoltaic generator-fed and a conventional voltage-fed ZSI differs from each other.

The derived small-signal model was used to develop deterministic procedure to design the control system of the inverter. It is concluded that a feedback loop that adjusts the shootthrough duty cycle should be used to regulate the input voltage of the inverter. Under input voltage control, there is no tradeoff in between the parameters of the impedance network and impedance network capacitor voltage control bandwidth. Also the small mismatch in the impedance network parameters do not compromise the performance of the inverter. These phenomena will remain hidden if the effect of the photovoltaic generator is not taken into account. In addition, the dynamic properties of the ZSI-based PV inverter was compared to single and two-stage VSI-based inverters. It is shown that the output impedance of ZSI-based inverter is similar to VSI-based inverter if the input voltage control is designed according to method presented in the thesis. In addition, it is shown that the settling time of the system, which determines the maximum power point tracking performance, is similar to two-stage VSI-based inverter.

The control of the ZSI-based PV inverter is more complicated than the control of the VSIbased inverter. However, with the model presented in this thesis, it is possible to guarantee that the performance of the inverter resembles the behavior of the two-stage VSI, i.e. the use of ZSI in interfacing of photovoltaic generators is not limited by its dynamic properties.

THESIS LINK : https://trepo.tuni.fi/handle/10024/213108

Montagem e teste de bateria de íon-lítio

 

Modelado y simulación de sistemas de almacenamiento de energía fotovoltaica en Matlab-PARTE 2

 

Modelado y simulación de sistemas de almacenamiento de energía fotovoltaica en Matlab-PARTE 1

 

INDUÇÃO ELETROMAGNETICA

 

PROJETO DE CIRCUITO -CURSO ELETRONICA DE POTENCIA-PARTE1

 

Capacitores de segurança (tipo X, tipo Y), interferência de modo comum e interferência de modo diferencial.

 

Projeto moderno de fonte de alimentação comutada, fechando circuitos de feedback usando o Simplis

 

Experimento con circuito inversor SPWM monofásico (multiplicacion de frequencia)-PARTE2

 

Single-phase SPWM inverter circuit experiment (unipolar frequency multiplication, bipolar SPWM)-单相SPWM逆变电路实验(单极性倍频)实验前讲解-PART1

 ENGLISH LEGENDED VERSION

 ENGLISH SPEAKING VERSION

사고아크검출장치 신뢰성 평가 시스템 및 평가절차 개발 -Development of the Reliability Evaluation System and Procedures for the Arc-Fault Detection Device-이진식(Jinsik Lee) ; 김정기(Jeong-Gi Kim) ; 김재현(Jae-Hyun Kim) ; 전정채(Jeong Chay Jeon)

 

Development of the Reliability Evaluation System and Procedures for the Arc-Fault Detection Device 사고아크검출장치 신뢰성 평가 시스템 및 평가절차 개발 Jinsik Lee · Jeong-Gi Kim · Jae-Hyun Kim · Jeong Chay Jeon

Abstract 

Arc-fault Detection Devices (AFDDs) which cut off the electric power supply under the event of a fire are adopted in many countries to protect life and property from electric fires. However, a controversy over proper or unwanted trips persists for some adopters in the real fields. To alleviate the controversy, this paper describes the reliability evaluation system for AFDD which automates and extends the unwanted tripping test in IEC 62606. The developed reliability evaluation system considers various conditions on the power source quality, the physical state of wiring circuits, and running electrical appliances. System controller automatically switches and repeats numerous pre-designed testing conditions in order not to be constrained by time. Also, it measures the electrical and operating information to give objective evaluation results to stakeholders. Consequently, the proposed AFDD reliability evaluation can produce more detailed conditions which make AFDD to show unwanted trips and it might improve the reliability of AFDDs by upgrading their algorithm to detect electric arc.

ORIGINAL KOREAN VERSION:  http://journal.auric.kr/kiee/XmlViewer/f449656

MODELING AND HARDWARE FOR THE IMPLEMENTATION OF AN ELECTRONIC CONTROL UNIT FOR A MAGNETRON Kursakov L. A., Agoev A. Z., Kunashev Z. A., Melyazhev A. A., Gaev D. S.

 

MODELING AND HARDWARE FOR THE IMPLEMENTATION OF AN ELECTRONIC CONTROL UNIT FOR A MAGNETRON Kursakov L. A., Agoev A. Z., Kunashev Z. A., Melyazhev A. A., Gaev D. S. Abstract. The paper presents the results of the development of a magnetron power supply unit for ion sputtering installations of non-magnetic materials, which provides smooth and precise control of magne-tron power at direct current. The operation of the electronic unit was simu-lated in the Multisim software environment. The hardware implementation of the electronic power unit for controlling and powering the magnetron is made on a modern electronic component base. The results of experimental tests of the electronic unit are presented.

SEE  FULL ARTICLE: https://www.mediafire.com/file/u0gljenkd7ih1cm/2-MNPK-ESSUiK-2024-115-120.en.mono_Com+marca+d'água.pdf/file

Dynamic Effect of Input-Voltage Feedforward in Three-Phase Grid-Forming Inverters -Berg, Matias; Roinila, Tomi (2020)-Electrical Engineering, Tampere University, 33720 Tampere, Finland; tomi.roinila@tuni.fi

 ABSTRACT

Grid-connected and grid-forming inverters play essential roles in the utilization of renewable energy. One problem of such a converter system is the voltage deviations in the DC-link between the source and the inverter that can disrupt the inverter output voltage. A common method to prevent these voltage deviations is to apply an input-voltage feedforward control. However, the feedforward control has detrimental effects on the inverter dynamics. It is shown that the effect of the feedforward in the input-to-output dynamics is not ideal due to the delay in the digital control system. The delay affects the input-to-output dynamics at high frequencies, and only a minor improvement can be achieved by low-pass filtering the feedforward control signal. Furthermore, the feedforward control can remarkably affect the inverter input admittance, and therefore, impedance-based stability problems may arise at the DC interface. This paper proposes a method based on linearization and extra element theorem to model the effect of the feedforward control in the inverter dynamics. Experimental measurements are shown to demonstrate the effectiveness of the proposed model. 

 LINK :https://trepo.tuni.fi/handle/10024/217417

Design and Implementation of New Oscillating Power Compensator With Improved Control Method Applied to Single-Phase Solar Inverter Pichan, Mohammad; Mousavi, Ameneh; Hafezi, Hosein; Kianifar, Ali (2025-07-13)

 

Design and Implementation of New Oscillating Power Compensator With Improved Control Method Applied to Single-Phase Solar Inverter Pichan, Mohammad; Mousavi, Ameneh; Hafezi, Hosein; Kianifar, Ali (2025-07-13) 

ABSTRACT

 Single-phase power systems inherently exhibit second-harmonic power oscillations, which can degrade photovoltaic (PV) system performance by reducing efficiency, shortening panel lifespan, and increasing AC current harmonic distortion. Conventional compensation techniques often rely on the main inverter topology, require additional passive components, or involve complex control strategies with limited robustness. This paper proposes a fully independent parallel compensator, implemented as a voltage-controlled current source, to effectively suppress PV current ripple. A hybrid control strategy is introduced, combining a proportional-resonant (PR) controller for steady-state error elimination with a Dead-Beat (DB) controller to ensure fast dynamic response. Additionally, a robust LMI-based PR controller is designed to enhance system performance under varying operating conditions. Simulation results demonstrate that the proposed system reduces current ripple from 10 to 0.5 A, offering a simple, efficient, and inverter-independent solution for PV ripple compensation.

SEE FULL ARTICLE: https://trepo.tuni.fi/handle/10024/229699

Hardware-in-the-Loop Methods for Stability Analysis of Multiple Parallel Inverters in Three-Phase AC Systems Alenius, Henrik; Roinila, Tomi; Luhtala, Roni; Messo, Tuomas; Burstein, Andrew; de Jong, Erik; Fabian, Alejandra (2020)

Hardware-in-the-Loop Methods for Stability Analysis of Multiple Parallel Inverters in Three-Phase AC Systems Henrik Alenius , Member, IEEE, Tomi Roinila , Member, IEEE, Roni Luhtala , Member, IEEE, Tuomas Messo , Member, IEEE, Andrew Burstein, Member, IEEE, Erik de Jong, Senior Member, IEEE, and Alejandra Fabian

Abstract—Modern electric distribution systems typically contain several feedback-controlled parallel inverters that together form a complex power distribution system. Consequently, a number of issues related to stability arise due to interactions among multiple inverter subsystems. Recent studies have presented methods where the stability and other dynamic characteristics of a paralleled inverter system can be effectively analyzed using impedance measurements. This article presents implementation techniques for comprehensive online stability analysis of grid-connected paralleled inverters using power hardware-in-the-loop measurements based on an OPAL-RT real-time simulator. The analysis is based on simultaneous online measurements of current control loop gains of the inverters and the grid impedance, and aggregated terminal admittance measurements of the inverters. The analysis includes the measurement of the inverters’ aggregated output impedance, inverters’ loop gains, global minor loop gain, and grid impedance. The presented methods make it possible to rapidly evaluate the system on both global and local levels in real time, thereby providing means for online stability monitoring or adaptive control of such systems. Experimental measurements are shown from a high-power energy distribution system recently developed at DNV GL, Arnhem, The Netherlands.

SEE FULL ARTICLE WEB : https://trepo.tuni.fi/handle/10024/217660

Droop-based Co-ordination of Grid-Forming and Grid-Following Inverters Ensuring Stability in a Microgrid Riaz, Nida; Peltonen, Lasse; Repo, Sami; Järventausta, Pertti (2025)

 Droop-based Co-ordination of Grid-Forming and Grid-Following Inverters Ensuring Stability in a Microgrid

Riaz, Nida; Peltonen, Lasse; Repo, Sami; Järventausta, Pertti (2025)

Abstract -This paper presents the droop-based co-ordination for active and reactive power-sharing between grid-forming (GFM) and grid-following (GFL) inverters. A 12 MVA inverter-based microgrid with two photovoltaic (PV) systems, 1 km apart is simulated to analyze the impact of different inverter control strategies on power-sharing and microgrid’s frequency response. Three simulation cases are studied for different combinations of GFM and GFL inverters, keeping the total PV headroom same (4 MVA) for regulation in all cases. Two grid-supporting GFM units (2 MVA headroom on each unit) in parallel operation results in 61% RoCoF reduction and 0.54 Hz less frequency nadir as compared to the case when one grid-supporting GFM operates in parallel with a grid-supporting GFL unit. When a GFL unit is operating together with a GFM unit, the choice of droop coefficients, inverter control mode and headroom capacity allocation plays a crucial role in overall frequency response. A grid-supporting GFM unit (4 MVA headroom capacity) in parallel with a grid-feeding GFL unit provides comparatively improved damping and frequency response with 39% reduction in RoCoF and 0.42 Hz improvement in the frequency nadir as compared to the case when both GFM and GFL units in parallel regulate the frequency.

SEE FULL ARTICLE : https://trepo.tuni.fi/handle/10024/231494