Fault monitoring and control of PEM fuel cell as backup power for UPS applications

This paper presents the expert fault monitoring and intelligent comprehensive control of a proton exchange membrane (PEM) fuel cell (PEMFC) as backup power source for an uninterruptible power supply (UPS) system. The failure status can be shown on the screen of a micro-computer (or a PC) linked with the UPS through an RS-232 and on the control panel of the UPS through LED indicator lights. The proposed intelligent comprehensive monitors and controllers of PEMFC and UPS can supply high quality power with flexible conversion functions, leading to the establishment of reliable power management for UPS applications. Finally, a suitable strategy and technique of fault monitoring and control for a UPS hybrid system with backup PEMFC and battery is implemented. The performances of the monitors and controllers are evaluated by experimental results, showing that the developed UPS system with backup PEMFC and battery power sources is suitable for industry applications. © 2009 IEEE

A comparison of online electrochemical spectroscopy impedance estimation of batteries

This paper compares methods of undertaking on-line electrochemical impedance spectroscopy that have been published in literature. This work describes the different published methodologies and sorts these into categories. The paper looks at the theoretical analysis of the circuits and control techniques and follows up with simulation and/or experimental studies of these methods. This work focuses on battery systems

A Review on Battery Charging and Discharging Control Strategies: Application to Renewable Energy Systems

[EN] Energy storage has become a fundamental component in renewable energy systems, especially those including batteries. However, in charging and discharging processes, some of the parameters are not controlled by the battery's user. That uncontrolled working leads to aging of the batteries and a reduction of their life cycle. Therefore, it causes an early replacement. Development of control methods seeks battery protection and a longer life expectancy, thus the constant-current-constant-voltage method is mostly used. However, several studies show that charging time can be reduced by using fuzzy logic control or model predictive control. Another benefit is temperature control. This paper reviews the existing control methods used to control charging and discharging processes, focusing on their impacts on battery life. Classical and modern methods are studied together in order to find the best approach to real systems.The authors would like to acknowledge the research project “Implementación de un programa de desarrollo e investigación de energías renovables en el departamento del Chocó, BPIN 2013000100285” and the Universidad Tecnológica del Chocó.Banguero-Palacios, E.; Correcher Salvador, A.; Pérez-Navarro, Á.; Morant Anglada, FJ.; Aristizabal Cardona, AJ. (2018). A Review on Battery Charging and Discharging Control Strategies: Application to Renewable Energy Systems. Energies. 11(4):1-15. https://doi.org/10.3390/en11041021S11511

Power converters and controllers for UPS applications with backup PEM fuel cell

This paper studies the practical cost-effective DC/DC converter, DC/AC inverter and AC/DC rectifier for an uninterruptible power supply (UPS) system with backup proton exchange membrane fuel cell (PEMFC). Furthermore, a comprehensive controller for the PEMFC is designed according to the change of the load, while the energy storage elements, such as battery and ultracapacitor, are chosen in order to compensate the slow dynamic response of PEMFC and to meet the sudden peak load energy demand. The designed power converters can supply high quality power with flexible conversion functions, leading to the establishment of reliable power management for UPS applications. Finally, a suitable control strategy and technique, capable of coping with the change of the load for PEMFC and realizing the energy managements of UPS hybrid system, is implemented. The performances of the proposed power converters and controllers are evaluated by experimental results, showing that the developed UPS system with backup PEMFC and battery power sources is suitable for industry applications. © 2008 IEEE

Power management and control stategies of renewable energy resources for micro-grid application

Microgrids (MGs) have become an increasingly familiar power sector feature in recent years and goes through the increase of renewable energies penetration. MG is defined as a group of interconnected loads and multiple distributed generators that is able to operate in grid-connected or islanding mode. Recent reports claim dramatic growth in projects planned for hundreds of GWs worldwide. Notably, following to many natural disasters, the concept of MG and its perceived benefits shifted beyond economic and environmental goals towards resilience. Consequently, MGs have begun to find a natural place in the regulatory and policy arena. Remote areas, facilities with low-quality local energy resources and critical infrastructure are all potential need the MGs solution. However, MGs have some disadvantages as the complexity of control and integration to keep the power quality to acceptable standards. The energy storage system requires more space and maintenance. Finally, protection is one of the important challenges facing the implementation of MGs. The present doctoral research is based on the philosophy of MGs for optimal integration and power management in an effective and efficient way to provide a sustainable and reliable power supply to consumers while reducing the overall cost. This work proposes a novel control strategies and design approaches of micro-grids for remote areas and grid connected system in which both the reliability of continuous power supply and power quality issues are treated. Moreover, this thesis also introduces the concept of Net Zero Energy House in which the system is designed in such a way that the house produces as much energy as it consumes over the year. Many controls algorithms have been investigated in order to find the best way to reduce the sensors’ number and the degree of control complexity while keeping better power quality as well as the system reliability. The developed concept is successfully validated through simulation as well as extensive experimental investigations. Particular attention is paid to the optimal integration of MGs based on the climate data of Central African States

Technological Capability in Industry 4.0: A Literature Review for Small and Medium Manufactures Challenges

Technological capabilities work as a basis for one to adapt and compete with the rapid pace of Industry 4.0 as without it worried the industry would get left behind hence this paper intends to give the low-down on the issues encountered regarding the technological capabilities in small and medium manufacturing enterprise (SME) due to the rise of Fourth Industrial revolution in manufacturing industry. Methods used are by reviews the literature on technological capabilities in the manufacturing sector based on journal articles, online news and books that strictly related to the keywords and research area. The concerns encountered in this paper are regarding the components of technological capabilities, and the challenges of technological capabilities face by manufacturers SME in Malaysia. Although a lot of researches uncover only the ground of technological capabilities hence there is a need to hit the books on the research area. Both empirical and non-empirical must carry out to discover more issues related to technological capabilities, and the study only covers the small and medium manufacturing enterprises in Malaysia

Analysis and Design of High Efficiency Grid-to-Vehicle (G2V) Plug-in Chargers for Local e-Transportation

Electric transportation worldwide has witnessed a tremendous increase in the use of electric vehicles (EV's) due to increased awareness of environmental issues. Road EV's compromise a broad spectrum of vehicles right from two-wheelers three-wheelers (rickshaws/Auto/Trio), cars and electric buses. E-Rickshaw has gained popularity in the Asian market post-2010 because of their symbolic resemblance with traditional auto-rickshaw. The fast growth of the market is principally pushed by the low ownership cost of electric three-wheelers, falling battery prices, and favorable government policies and support. These EVs run on low-cost 48 V, 120 Ah lead acid battery packs having low depth-of-discharge (DOD). Hence, frequent battery charging becomes essential for such EVs. Conventional battery chargers available in the market utilize flyback converter based topologies in order to charge such battery packs. On one hand such battery chargers are easy to implement, these topologies fail to achieve unity power factor (UPF) operation leading to high total harmonic distortion (THD) and poor input power quality at the input. Thus active power factor correction (PFC) becomes a vital constituent in AC-DC converters. By understanding the constraints posed by continuous current mode (CCM) based battery chargers, the proposed converters are designed to operate in discontinuous current mode (DCM) because of its evident benefits such as inherent PFC, zero current turn-on and zero diode reverse recovery losses. By omitting sensors at the input and utilizing only the output sensors, regulated voltage or current can be obtained which makes the system cost-effective and improves its reliability and robustness to high frequency noise. This thesis presents both isolated and non-isolated battery charger for local e-transportation EVs utilizing 48 V lead acid battery pack. At first, a non-isolated single-stage interleaved buck-boost float charger is proposed by considering the advantages such as reduced current stresses, minimum number of semiconductor devices and absence of bulky high frequency transformer. DCM operation of the proposed converter ensure UPF operation for variable input voltage and utilizing just a single sensor makes this charger configuration economical and easy to implement. However, such a configuration had high current stress on the semiconductor devices leading to increased thermal requirement and reduced efficiency at light loads. Thus addressing these problems, a high efficiency two-stage battery charger is proposed. The battery charger uses an interleaved DCM buck-boost converter in order to achieve PFC at variable input voltage, whereas the second stage is an unregulated half-bridge LLC resonant converter which provides isolation as well as soft-switching for the primary switches. Synchronous rectification (SR) along with only capacitive filter is used on center tapped transformer secondary to improve converter efficiency. Due to DCM of the front-end AC-DC converter achieves zero current turn-on of the switches and DC-DC converter switches achieve zero voltage turn-on because of the LLC resonant. The proposed battery charger implements constant current (CC) and constant voltage (CV) method of charging using simple PI controllers, thus making it suitable for commercial use. Small signal models for both the battery charger configurations are developed using the current injected equivalent circuit approach and a detailed controller design is illustrated. Simulation results using PSIM11.1 software and experimental results from proof-of-concept laboratory hardware prototypes are provided in order to validate the reported analysis and design which demonstrates their performance