Showing papers on "Power management published in 2022"

A Power Management Scheme for Grid-connected PV Integrated with Hybrid Energy Storage System

Abstract: The penetration of renewable energy sources (RESs) in the distribution system becomes a challenge for the reliable and safe operation of the existing power system. The sporadic characteristics of sustainable energy sources along with the random load variations greatly affect the power quality and stability of the system. Hence, it requires storage Systems with both high energy and high power handling capacity to coexist in microgrids. An efficient energy management structure is designed in this paper for a grid-connected PV system combined with hybrid storage of supercapacitor and battery. The combined supercapacitor and battery storage system grips the average and transient power changes, which provides a quick control for the DC-link voltage, i. e., it stabilizes the system and helps achieve the PV power smoothing. The average power distribution between the power grid and battery is done by checking the state of charge (SOC) of a battery, and an effective and efficient energy management scheme is proposed. Additionally, the use of a supercapacitor lessens the current stress on the battery system during unexpected disparity in the generated power and load requirement. The performance and efficacy of the proposed energy management scheme are justified by simulation studies.

Powering Solutions for Biomedical Sensors and Implants Inside the Human Body: A Comprehensive Review on Energy Harvesting Units, Energy Storage, and Wireless Power Transfer Techniques

Abstract: For implantable medical devices, it is of paramount importance to ensure uninterrupted energy supply to different circuits and subcircuits. Instead of relying on battery stored energy, harvesting energy from the human body and any external environmental sources surrounding the human body ensures prolonged life of the implantable devices and comfort of the patients. In this article, we present existing issues and challenges related to the state-of-the-art solutions used for harvesting energy to power implantable devices. In addition, the details on existing energy storage technologies and various wireless power transfer techniques incorporating external or internal energy sources and sensors have been discussed. The authors have outlined the performance and power constraints of existing biomedical devices and provided a brief overview of various power architectures found in the literature. This survey has been conducted on existing implantable solutions in terms of output voltage, current, device dimension, application, generated power, energy density, and so on. Finally, the advantages and drawbacks of different solutions have been discussed and compared. Therefore, this article can be considered as an expedient reference for researchers conducting research in the field of energy scavenging, internal energy storage, wireless power transfer techniques, and power management of implantable medical devices.

Current Progress on Power Management Systems for Triboelectric Nanogenerators

Abstract: This article presents a review on the development of power management systems (PMSs) for triboelectric nanogenerators (TENGs). The TENG is the most recent technology to harvest ambient mechanical energy from the environment and human activities. Its invention was motivated by the prospect of building self-powered systems. The TENG has several appealing advantages, such as high power density, high voltage output, high efficiency at low frequency, and low cost. However, due to the TENG's unique nonlinear electrical property and capacitive behavior, the development of its PMS has presented great challenges as compared to other energy harvesters. The objective of PMS design has evolved from boosting the peak output power, to increasing the energy stored in a capacitor, and to increasing the steady-state output power of a resistive load by using a power converter. Driven by the need to build self-powered systems, the switches in the TENG PMS have evolved from active switches to passive switches. The past decade has witnessed exciting breakthroughs in the development of TENG PMS, yet there are still unlimited opportunities in exploring TENG's energy generation mechanism and vast potential in boosting energy extraction from the TENG by designing effective power converter topologies.

Power Electronics Converter Technology Integrated Energy Storage Management in Electric Vehicles: Emerging Trends, Analytical Assessment and Future Research Opportunities

Abstract: Globally, the research on electric vehicles (EVs) has become increasingly popular due to their capacity to reduce carbon emissions and global warming impacts. The effectiveness of EVs depends on appropriate functionality and management of battery energy storage. Nevertheless, the battery energy storage in EVs provides an unregulated, unstable power supply and has significant voltage drops. To address these concerns, power electronics converter technology in EVs is necessary to achieve a stable and reliable power transmission. Although various EV converters provide significant contributions, they have limitations with regard to high components, high switching loss, high current stress, computational complexity, and slow dynamic response. Thus, this paper presents the emerging trends in analytical assessment of power electronics converter technology incorporated energy storage management in EVs. Hundreds (100) of the most significant and highly prominent articles on power converters for EVs are studied and investigated, employing the Scopus database under predetermined factors to explore the emerging trends. The results reveal that 57% of articles emphasize modeling, experimental work, and performance evaluation. In comparison, 13% of papers are based on problem formulation and simulation analysis, and 8% of articles are survey, case studies, and review-based. Besides, four countries, including China, India, the United States, and Canada, are dominant to publish the maximum articles, indicating 33, 17, 14, and 13, respectively. This review adopts the analytical assessment that outlines various power converters, energy storage, controller, optimization, energy efficiency, energy management, and energy transfer, emphasizing various schemes, key contributions, and research gaps. Besides, this paper discusses the drawbacks and issues of the various power converters and highlights future research opportunities to address the existing limitations. This analytical assessment could be useful to EV engineers and automobile companies towards the development of advanced energy storage management interfacing power electronics for sustainable EV applications.

Secure power management strategy for direct torque controlled fuel cell/ supercapacitor electric vehicles

Abstract: High reliability is recommended in hybrid electric vehicle applications. In this study, a secure power management strategy has been developed for a fuel cell—supercapacitor hybrid electric vehicle. In addition to its ability to detect the occurrence of failures in vehicle power sources, the proposed power management strategy isolates the faulty source and reconfigures the control scheme to always guarantee bus voltage stability and vehicle traction even in faulty situations. The developed power management strategy enhances vehicle comfort and prevents exhausting one source over another by allowing the fuel cell and the supercapacitor to operate at different power levels. The multiloop control scheme associated with the power sources is highly reliable since both sources can run the vehicle alone and regulate the bus voltage. Vehicle speed and torque controllers are simultaneously tuned using a particle swarm optimization algorithm. Torque and speed ripples are automatically minimized via the use of a new proposed cost function. This approach made the controller design easier and gave the designer the possibility to tradeoff between the variables to be minimized.

Recent Progress of Switching Power Management for Triboelectric Nanogenerators

Abstract: Based on the coupling effect of contact electrification and electrostatic induction, the triboelectric nanogenerator (TENG) as an emerging energy technology can effectively harvest mechanical energy from the ambient environment. However, due to its inherent property of large impedance, the TENG shows high voltage, low current and limited output power, which cannot satisfy the stable power supply requirements of conventional electronics. As the interface unit between the TENG and load devices, the power management circuit can perform significant functions of voltage and impedance conversion for efficient energy supply and storage. Here, a review of the recent progress of switching power management for TENGs is introduced. Firstly, the fundamentals of the TENG are briefly introduced. Secondly, according to the switch types, the existing power management methods are summarized and divided into four categories: travel switch, voltage trigger switch, transistor switch of discrete components and integrated circuit switch. The switch structure and power management principle of each type are reviewed in detail. Finally, the advantages and drawbacks of various switching power management circuits for TENGs are systematically summarized, and the challenges and development of further research are prospected.

A nonlinear double‐integral sliding mode controller design for hybrid energy storage systems and solar photovoltaic units to enhance the power management in DC microgrids

Abstract: Correspondence Tushar Kanti Roy, Department of Electronics, and Telecommunication Engineering, Rajshahi University of Engineering & Technology, Rajshahi 6204, Bangladesh. Email: tkroy@ete.ruet.ac.bd Abstract In this paper, a nonlinear decentralized double-integral sliding mode controller (DI-SMC) is designed along with an energy management system (EMS) for the DC microgrid (DCMG). This DCMG includes having a hybrid energy storage system (HESS) that incorporates a battery energy storage system (BESS) and supercapacitor energy storage system (SCESS) while the load demand is met through the power generated from solar photovoltaic (SPV) units. First, dynamical models of each subsystem of DCMGs such as the SPV system, BESS, and SCESS are developed to capture highly nonlinear behaviors of DCMGs under various operating conditions. The proposed nonlinear DI-SMC is then designed for each power unit in DCMGs to ensure the desired voltage level at the common DC-bus and appropriate power dispatch of different components to fulfill the load requirement of the DCMG. On the other hand, an energy management system (EMS) is designed to determine the set point for the controller with an aim of ensuring the power balance within DCMGs under various operating conditions where the overall stability is assessed using the Lyapunov theory. Simulation studies along with the processor-in-loop validation, including a comparative study with a proportional-integral (PI) controller, verify the applicability and effectiveness of the EMS-based DI-SMC under different operating conditions of the DCMG.

Design and Control of DC–DC Converters in a PV-Based LVDC Microgrid

Abstract: Over the last decade, power generation using renewable energy resources has gained noteworthy limelight due to concerns about the environment, escalated global energy demand and depletion of fossil fuel. In this context, among several renewable energy sources (RES), solar photovoltaic (PV) has become a significant contributor of power in terms of annual addition to total power capacity. This is mainly because of the eco-friendly nature and its competence endeavoring lesser running tariff over the long run. However, the power generation from PV becomes unreliable due to the intermittent behavior. Thus, energy storage systems (ESS) are incorporated, ensuring uninterruptible power supply to fulfill the load requirement. In recent days, among several energy storage devices, battery and supercapacitor (SC) are widely incorporated in microgrid applications. The complementary characteristic of battery and SC with respect to energy and power density is grouped to form a hybrid energy storage system (HESS). The efficient utilization of the HESS within microgrid is dependent on control methodologies used in order to manage the power balance, faster DC-link voltage restoration and stabilization. Here, in this chapter, an effort has been made to design the converters required for the PV-based LVDC microgrid. Also, the design of a coordinated controller and optimum power management scheme for a 48 V stand-alone LVDC microgrid typically for residential application is also presented.

An efficient SoC-balancing based power management strategy for interconnected subgrids of DC microgrid

Abstract: In this paper, a coordinated power management strategy is proposed for voltage restoration, SoC balancing, and distributed power sharing among the interconnected subgrids of a dc microgrid (DC-MG). In the proposed strategy, coordinated secondary controllers are implemented on the upper layer of generalized primary controls of distributed generators (DGs) and interlinking bidirectional converter (IBC). The primary controllers can be implemented in a decentralized power management strategy using the dc bus voltage deviation of each subgrid. However, to eliminate the voltage deviations and to restore the dc bus voltage at their nominal value, secondary controllers are implemented to all distributed sources. The secondary controller may hamper the effectiveness of the decentralized power management technique. Hence, to resolve this issue, a coordinated secondary IBC controller based on SoC and charging/discharging power of energy storage system (ESS) is proposed. The proposed secondary IBC controller re-establishes a distributed power sharing strategy among the subgrids with limited information through low bandwidth communication (LBC). Further, a dc bus-signaling-based state transition strategy for PV, battery, and IBC controllers is proposed to optimize the performance of the battery and efficiently utilize the PV generations. The feasibility of the proposed strategy is verified by MATLAB simulation and OPAL-RT real-time digital simulator. • A dc bus-signaling-based state transition strategy is developed for generation-storage coordination. • An SoC-based IBC secondary control strategy is developed for SoC balancing-based power sharing among the subgrids. • The proposed strategy can fast charge a low SoC battery which prevents a low SoC battery from deep discharge. • Moreover, during a fault condition, transient stability can be ensured without any additional mode detection scheme.

Online Power Management for Multi-Cores: A Reinforcement Learning Based Approach

Abstract: Power and energy is the first-class design constraint for multi-core processors and is a limiting factor for future-generation supercomputers. While modern processor design provides a wide range of mechanisms for power and energy optimization, it remains unclear how software can make the best use of them. This article presents a novel approach for runtime power optimization on modern multi-core systems. Our policy combines power capping and uncore frequency scaling to match the hardware power profile to the dynamically changing program behavior at runtime. We achieve this by employing reinforcement learning (RL) to automatically explore the energy-performance optimization space from training programs, learning the subtle relationships between the hardware power profile, the program characteristics, power consumption and program running times. Our RL framework then uses the learned knowledge to adapt the chip's power budget and uncore frequency to match the changing program phases for any new, previously unseen program. We evaluate our approach on two computing clusters by applying our techniques to 11 parallel programs that were not seen by our RL framework at the training stage. Experimental results show that our approach can reduce the system-level energy consumption by 12 percent, on average, with less than 3 percent of slowdown on the application performance. By lowering the uncore frequency to leave more energy budget to allow the processor cores to run at a higher frequency, our approach can reduce the energy consumption by up to 17 percent while improving the application performance by 5 percent for specific workloads.

Autonomous Power Management of Distributed Energy Storage Systems in Islanded Microgrids

Abstract: In this paper, an autonomous power management strategy is proposed for distributed energy storage units deployed in islanded microgrids with photovoltaic (PV) and droop controlled units. The proposed strategy offers controlled and selective prioritization of the charging/discharging actions while coordinating with PV and droop units to maintain power balance in the microgrid. The selective priority allows battery units with low state-of-charge (SOC) to keep charging, at a reduced or a full rate, while other battery units meet the demand. This is in contrast to the autonomous techniques in the literature where all units can only charge/discharge simultaneously. This is achieved by employing the proposed adaptive piecewise P/f characteristics, with breakpoints that enable seamless transition between power control and frequency regulation. The charging/discharging decisions and the amount of power exchanged with the microgrid, is determined autonomously at each unit using local measurements only. Also, the strategy offers a unidirectional shutdown mechanism where, below a certain SOC limit, it modifies the structure of the P/f characteristics so the unit cannot discharge, yet it can still charge anytime surplus generation becomes available. Simulation results from a detailed switching model, and also an averaged model, for prolonged simulation times, are used to validate the proposed strategy.