Efficient Power Management Strategy Research Articles

Efficient power management strategies for AC/DC microgrids with multiple voltage buses for sustainable renewable energy integration

This study proposes a distinct coordination control and power management approach for hybrid residential microgrids (MGs). The method enhances the feasibility of hybrid MGs by reducing power loss on ILBCs. The MG has been modeled with solar and wind generators. The MG comprises multiple direct current (DC) and alternating current (AC) sub-microgrids (SMGs) with varying voltage levels. The coordination control and power management strategies for autonomous hybrid MGs with primary and secondary control levels. A novel technique is proposed to ensure seamless and precise power transfer among SMGs while minimizing the constant operation of ILBCs in islanded mode, with a focus on the secondary control level. The study uses MATLAB/Simulink to analyze on-grid, off-grid, and transient mode power transfer among MG. The MG has been operative during transient/faulty conditions. The results indicate that the proposed method demonstrates excellent adaptability in managing power flow.

DC Power Boosting Circuit for Freestanding‐Sliding Triboelectric Nanogenerators with High Intrinsic Impedance and Multi‐Harmonic Output

AbstractThis study presents a freestanding sliding triboelectric nanogenerator (FS‐TENG) designed for low‐frequency motions (below 2 Hz). However, for practical applications, an efficient power management strategy is required to handle the harmonic outputs of the FS‐TENG. The high‐frequency signal is not sustainable for powering low‐power electronic applications. To address the issue, a novel direct current power supply circuit (DPS) is proposed that utilizes a double charge circuit (DCC) and a comb filtering circuit (CFC) to efficiently harness harmonic sources from the FS‐TENG. The direct power supply (DPS) outperforms traditional converters by reducing the impedance of the FS‐TENG and collecting the target harmonic sources, which facilitates a continuous power supply to the load. The results demonstrate that the DPS is capable of providing a continuous DC voltage of 2.2 V to a 10 MΩ load with minimal ripple (0.039%) at a low operating frequency of 0.625 Hz. Additionally, the practical application of a self‐powered temperature sensor is demonstrated to highlight the potential of FS‐TENG and DPS for low‐frequency energy harvesting solutions in real‐world scenarios.

DC Bus Voltage Stabilization and SOC Management Using Optimal Tuning of Controllers for Supercapacitor Based PV Hybrid Energy Storage System

The global initiative of decarbonization has led to the popularity of renewable energy sources, especially solar photovoltaic (PV) cells and energy storage systems. However, standalone battery-based energy storage systems are inefficient in terms of the shelf and cycle life, reliability, and overall performance, especially in instantaneous variations in solar irradiance and load. In order to overcome this, a combination of a supercapacitor and battery-based hybrid energy storage system (HESS) is considered as an emerging and viable solution. The present work proposes an optimally tuned tilt-integral (TI) controller to develop an efficient power management strategy (PMS) to enhance the overall system performance. The controller parameters are tuned by optimization of the time-domain design specifications using a gradient-free simplex search technique. The robustness of the proposed TI controller is demonstrated in comparison to PI and fractional-order PI (FOPI) controllers. Furthermore, extensive experimentation was carried out to analyze the effectiveness of the proposed approach for DC bus voltage stabilization and state-of-charge (SOC) management under varying operating conditions such as solar irradiance, load, temperature, and SOC consumption by battery.

An Efficient Power Management Strategy of a Solar Powered Smart Camera-road Side Unit Integrated Platform

Background: This paper proposes efficient employment of a self-powered VANET infrastructure. Miscellaneous techniques and algorithms are suggested to help the realization of such a framework. Objective: The current work attempts to enhance the network architecture of the Green VANET by adopting the self-powered fog computing concept for better networking, computing, and storage performance. Method: The green fog layer consists of three components: a self-powered edge server, Wireless Solar Routers (WSRs), and a new device resulting from the integration between a solar-powered Smart Camera (SC) and a solar-powered Road Side Unit (RSU) in order to create a better sensing mechanism of the road traffic. Result: A proper power management strategy is suggested and installed locally in the self-powered devices to decrease their power utilization by 80% and lengthen their batteries' lifetime from 17 to 64 hours. Conclusion: The different methods and algorithms suggested in this paper are realized and tested using an experimental framework based on a mix of evaluation kits. It is noticed that the suggested power management algorithm can adjust the duty cycling according to the accessible energy levels, and thus, the SC-RSU nodes and the WSRs keep on working in a pre-managed and arranged manner.

Efficient Power Management Strategy of Electric Vehicles Based Hybrid Renewable Energy

This paper presents a straightforward power management algorithm that supervises the contribution of more than one energy source for charging a vehicle, even if the car is in motion. The system is composed of a wireless charging system, photovoltaic (PV) generator, fuel cell (FC), and a battery system. It also contains a group of power converters associated with each energy resource to make the necessary adaptation between the input and output electrical signals. The boost converter relates to the PV/FC, and the boost–buck converter is connected with the battery pack. In this work, the wireless charging, FC, and PV systems are connected in parallel via a DC/DC converter for feeding the battery bank when the given energy is in excess. Therefore, for each of these elements, the mathematical model is formulated, then the corresponding power management loop is built, which presents the significant contribution of this paper. The efficient power management methodology proposed in this work was verified on Matlab/Simulink platforms. The battery state of charge and the hydrogen consumption obtained results were compared to show the effectiveness of this multi-source system.

Frequency superimposed energy bifurcation technology for a hybrid microgrid

A conventional microgrid comprising both ac and dc components undergoes a significant power loss during the multistage conversion process. To overcome the problem of reduced efficiency in a conventional microgrid, a significant attention has been drawn towards the structure of the hybrid ac/dc microgrid. The precise power management in a hybrid microgrid is relatively complicated due to the presence of the dc sub-grids in the architecture. In dc sub-grids, the converter power can only be controlled by regulating the output voltage. However, the computation of the reference voltage turns out to be a challenging task due to the system resistance. The complexity further increases as the line resistances associated with the interlinking converter differs. Addressing this issue, to implement an efficient power management strategy in a dc sub-grid, a superimposed virtual frequency based control variable is proposed in this work. The proposed control variable remains unaffected by the system impedance which helps to attain an efficient power bifurcation. The study extensively evaluates the maximum exchanged power, storage utilisation factor, and circulating power among the multiple interlinking converters. The proposed strategy efficiently manages the bidirectional power flow between the ac and dc sub-grids.

New Optimal Power Management Strategy for Series Plug-In Hybrid Electric Vehicles

Recently Plug-in hybrid electric vehicles (PHEVs) have gained increasing attention due to their ability to reduce the fuel consumption and emissions. In this paper a new efficient power management strategy is proposed for a series PHEV. According to the battery state of charge (SOC) and vehicle power requirement, a new rule-based optimal power controller with four different operating modes is designed to improve the fuel economy of the vehicle. Furthermore, the teaching-learning based optimization (TLBO) method is employed to find the optimal engine power and battery power under the specified driving cycle while the fuel consumption is considered as the fitness function. In order to demonstrate the effectiveness of the proposed method, four different driving cycles with various numbers of driving distances for each driving cycle are selected for the simulation study. The performance of the proposed optimal power management strategy is compared with the rule-based power management method. The results verify that the proposed power management method could significantly improve the fuel economy of the series PHEV for different driving conditions.

Power grand composite curves shaping for adaptive energy management of hybrid microgrids

This work proposes a systematic approach for the adaptive identification and implementation of efficient power management strategies (PMS) in the course of operation of hybrid renewable energy microgrids. The approach is based on the temporal evolution of the system power grand composite curve (PGCC), which is adaptively shaped on-line and within short-term time intervals to form a sequence of decisions indicating the instant and duration of activation of different subsystems. It builds on from previous work where the potential for system performance enhancement could not be exploited through pre-specified PMS identified off-line. More specifically, it involves a stored energy targeting step that exploits the PGCC to identify the desired operational profile of an accumulator during a prediction horizon in order to satisfy the system operating goals. The identified energy targets are subsequently enforced through a sequence of control actions that enable the exact matching of the PGCC hence resulting in a new PMS. The method is elaborated graphically for multiple potential operating goals and is supported by a formal mathematical model that captures system structural and temporal characteristics. It is implemented on an actual hybrid microgrid considering multiple RES-based energy generation and storage options for expected and unexpected weather conditions.

Techno-economic study of a PV-hydrogen-battery hybrid system for off-grid power supply: Impact of performances' ageing on optimal system sizing and competitiveness

The use of intermittent renewable energy sources for power supply to off-grid electricity consumers requires either additional power sources or energy storage solutions, in order to manage the time mismatch between energy production and load requirements.We investigate in this paper the interest of a hybrid solar energy system, including a lithium-based batteries bank and a hydrogen chain (electrolyser, gas storages and fuel cell), for an off-grid application. This system is compared with two reference cases: PV-diesel generator and PV-Batteries. These different systems have been represented using empirical and semi-empirical models and are simulated with the CEA made ODYSSEY platform.The originality of our study lies in the simultaneous optimisation of the power management strategy and the components’ size, and in the detailed modelling of the components (power consumption of the auxiliaries and ageing approach in the form of performances degradation).The PV-Batteries-H2 system is operated by an efficient power management strategy and its optimal sizing is assessed on the basis of technical (e.g. load satisfaction) and economic (e.g. levelized cost of electricity) criteria. The results highlight the important role of the hydrogen chain in reducing the cost of the supplied energy. It is also shown that performances degradation of the hydrogen chain has a limited impact on the system optimal sizing and economic results.

Far-Field RF Powering of Implantable Devices: Safety Considerations

Far-field RF powering is an attractive solution to the challenge of remotely powering devices implanted in living tissue. The purpose of this study is to characterize the peak obtainable power levels in a wireless myoelectric sensor implanted in a patient while maintaining safe local temperature and RF powering conditions. This can serve as a guide for the design of onboard electronics in related medical implants and provide motivation for more efficient power management strategies for implantable integrated circuits. Safe powering conditions and peak received power levels are established using a simplified theoretical analysis and Federal Communications Commission-established limits for radiating antennas. These conditions are subsequently affirmed and improved upon using the finite-element method and temperature modeling in bovine muscle.

Implantation d'un décodeur H.264 sur plateforme multiprocesseur avec gestion énergétique

Embedded systems have moved recently towards multiprocessor architectures to support the level of performance required by new mobile applications. For those systems, power is a sensitive aspect that points to the need for study and developement of efficient power management strategies. This paper presents a concrete case study in one of the primarily concerned application domain: multimedia and video broadcasting. It reports the implementation details of a H.264/AVC decoder on a multiprocessor platform (ARM11 MPCore EB) considering in particular the problem of power reduction using online and offline techniques ofpower management (DVFS, DPM).

Fuel efficient power management strategy for fuel cell hybrid powertrains

A real time control strategy for fuel cell hybrid vehicles is proposed. The objective is to reduce the hydrogen consumption by using an efficient power sharing strategy between the fuel cell system (FCS) and the energy buffer (EB). The energy buffer (battery or supercapacitor) is charge-sustained (no plug-in capabilities). The real time control strategy is derived from a non-causal optimization algorithm based on optimal control theory. The strategy is validated experimentally with a hardware-in-the-loop (HiL) test bench based on a 600 W fuel cell system.

Power management strategies for a stand-alone power system using renewable energy sources and hydrogen storage

A stand-alone power system based on a photovoltaic array and wind generators that stores the excessive energy from renewable energy sources (RES) in the form of hydrogen via water electrolysis for future use in a polymer electrolyte membrane (PEM) fuel cell is currently in operation at Neo Olvio of Xanthi, Greece. Efficient power management strategies (PMSs) for the system have been developed. The PMSs have been assessed on their capacity to meet the power load requirements through effective utilization of the electrolyzer and fuel cell under variable energy generation from RES (solar and wind). The evaluation of the PMS has been performed through simulated experiments with anticipated conditions over a typical four-month time period for the region of installation. The key decision factors for the PMSs are the level of the power provided by the RES and the state of charge (SOC) of the accumulator. Therefore, the operating policies for the hydrogen production via water electrolysis and the hydrogen consumption at the fuel cell depend on the excess or shortage of power from the RES and the level of SOC. A parametric sensitivity analysis investigates the influence of major operating variables for the PMSs such as the minimum SOC level and the operating characteristics of the electrolyzer and the fuel cell in the performance of the integrated system.