Techniques to Enhance Lifetime of Wireless Sensor Networks: A Survey

Increasing lifetime in wireless sensor networks is a major challenge because the nodes are equipped with low power battery. For increasing the lifetime of the sensor nodes energy efficient routing is one solution which minimizes maintenance cost and maximizes the overall performance of the nodes. In this paper, different energy efficient routing techniques are discussed. Here, photovoltaic cell for efficient power management in wireless sensor networks is also discussed which are developed to increase the lifetime of the nodes. Efficient battery usage techniques and discharge characteristics are then described which enhance the operational battery lifetime

Energy Consumption Rate based Stable Election Protocol (ECRSEP) for WSNs

In recent few yearsWireless Sensor Networks (WSNs) have seen an increased interest in various applications like border field security, disaster management and medical applications. So large number of sensor nodes are deployed for such applications, which can work autonomously. Due to small power batteries in WSNs, efficient utilization of battery power is an important factor. Clustering is an efficient technique to extend life time of sensor networks by reducing the energy consumption. In this paper, we propose a new protocol; Energy Consumption Rate based Stable Election Protocol (ECRSEP). Our CH selection scheme is based on the weighted election probabilities of each node according to the Energy Consumption Rate (ECR) of each node. We compare results of our proposed protocol with Low Energy Adaptive Clustering Hierarchy (LEACH), Distributed Energy Efficient Clustering (DEEC), Stable Election Protocol (SEP), and Enhanced SEP(ESEP). Our simulation results show that our proposed protocol, ECRSEP outperforms all these protocols in terms of network stability and network lifetime

All electric battery service vessel - Dynamic modeling of a battery fed IPMSM propulsion plant as a tool for energy estimates and functional description for an energy management system

"Designing an all-electric battery vessel, knowledge of the dynamic performance of the electrical propulsion plant becomes crucial to produce adequate estimates of needed battery capacity. An energy management system is to control the on-board power flow and ensure energy efficient operation of the vessel. This thesis presents a solution for dynamic simulation of an all-electric battery vessel based on an internal permanent magnet synchronous machine propulsion plant. Insight in system dynamics forms the basis of a proposed functional description for further design of an energy management system. Through description of the different modes and transitions between them, critical aspects and functionality of the control system are enlightened. The thesis presents a tuning guide showing how to tune the model to convergence using measured data from the vessel sea trial. When tuned, the presented model can be used for dimensioning future battery vessels. The model is designed in MATLAB Simulink. Key words: Energy management system, dynamic modeling, battery vessel, IPMSM, electric propulsion.

The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

An energy saving scheme for key management protocol in IEEE802.16e

In IEEE 802.16e, energy management is an important factor to be emphasized especially for Mobile Stations (MSs) due to their limitation on battery capabilities. Efficient energy scheme would guarantees long lifetime for MSs. In WiMAX service, the Base Station (BS) sends security keys to MSs using key management scheme, and MSs need to perform ciphering operations to get access to the security keys for further processing. In this way, performing high ciphering operations by MSs require more energy. This paper proposes an Efficient Key Management Scheme (EKMS) using complete binary tree structure to mitigate this issue, this is done by reducing energy consumption of MSs needed to execute key management process. Analysis shows that EKMS save energy in MSs during key management

Holistic Management of Energy Storage System for Electric Vehicles

While electric vehicles (EVs) have recently gained popularity owing to their economic and environmental benefits, they have not yet dominated conventional combustion-engine vehicles in the market. This is due mainly to their short driving range, high cost and/or quick battery performance degradation. One way to mitigate these shortcomings is to optimize the driving range and the degradation rate with a more efficient battery management system (BMS). This dissertation explores how a more efficient BMS can extend EVs' driving range during their warranty periods. Without changing the battery capacity/size, the driving range and the degradation rate can be optimized by adaptively regulating main operational conditions: battery ambient temperature (T), the amount of transferred battery energy, discharge/charge current (I), and the range of operating voltage (min/max V). To this end, we build a real-time adaptive BMS from a cyber-physical system (CPS) perspective. This adaptive BMS calculates target operation conditions (T, I, min/max V) based on: (a) a battery performance model that captures the effects of operational conditions on the degradation rate and the driving range; (b) a real-time battery power predictor; and (c) a temperature and discharge/charge current scheduler to determine target battery operation conditions that guarantee the warranty period and maximize the driving range. Physical components of the CPS actuate battery control knobs to achieve the target operational conditions scheduled by the batteries cyber components of CPS. There are two subcomponents for each condition (T, I): (d) a battery thermal management system and (e) a battery discharge/charge current management system that consists of algorithms and hardware platforms for each sub-system. This dissertation demonstrates that a more efficient real-time BMS can provide EVs with necessary energy for the specified period of time while slowing down performance degradation. Our proposed BMS adjusts temperature and discharge/charge current in real time, considering battery power requirements and behavior patterns, so as to maximize the battery performance for all battery types and drivers. It offers valuable insight into both current and future energy storage systems, providing more adaptability and practicality for various mobile applications such as unmanned aerial vehicles (UAV) and cellular phones with new types of energy storages.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/143920/1/kimsun_1.pd

Effect of noise factors in energy management of series plug-in hybrid electric vehicles

It has been demonstrated that charge depletion (CD) energy management strategies are more efficient choices for energy management of plug-in hybrid electric vehicles (PHEVs). The knowledge of drive cycle as a priori can improve the performance of CD energy management in PHEVs. However, there are many noise factors which affect both drivetrain power demand and vehicle performance even in identical drive cycles. In this research, the effect of each noise factor is investigated by introducing the concept of power cycle instead of drive cycle for a journey. Based on the nature of the noise factors, a practical solution for developing a power-cycle library is introduced. Investigating the predicted power cycle, an energy management strategy is developed which considers the influence of temperature noise factor on engine performance. The effect of different environmental and geographic conditions, driver behavior, aging of battery and other components are considered. Simulation results for a modelled series PHEV similar to GM Volt show that the suggested energy management strategy based on the driver power cycle library improves both vehicle fuel economy and battery health by reducing battery load and temperature.<br /

Energy management and sizing of a hybrid locomotive

The French national railways company (SNCF) is involved in a new project which aims at investigating and testing energy efficient and environmentally friendly traction systems of a hybrid locomotive called LHyDIE. This paper presents a new methodology for the hybrid electric vehicle design which exploits an energy management strategy based on a frequency approach. In particular, the design of the LHyDIE prototype and the energy management strategy implemented aboard are presented. The study mainly focuses on the battery and supercapacitor sizing taking account of the intrinsic energetic characteristics of these sources (i.e. energy and power densities, typical operating frequency) in the energy management strategy. The analysis of feasible configurations of the traction device determined in compliance with the battery stress, the system cost and the diesel oil consumption criteria and volume constraints is presented

Development of Battery Control and Power Conversion for Renewable Energy Utilization

Energy storage systems have many applications including making the power grid more efficient, reliable, and economical and assisting in efficiently integrating renewable energy. A battery management system is necessary to monitor and maintain safe, optimal operation of each battery stack in the energy storage system. The purpose of this research is to create and implement an advanced graphical user interface for a battery management system (BMS). The BMS will allow each battery into the stack to be individually monitored and managed while allowing different charging profiles to be applied. The graphical user interface will be created on the Linux QT platform and displayed on a BeagleBone microcontroller board. This embedded board will then be implemented into the physical circuitry of the battery management system. The battery management system being designed for is unique in the fact that individual batteries can be isolated. This means that while some batteries are charging, others can be supplying the load. As a result, the system is more reliable which can help it economically and quickly meet peak loads or eliminate short term power outages, for example. Currently peak loads are met by operating power plants at a higher capacity than what is needed to meet unexpected surges. Wind and solar energy are intermittent and therefore provide varying unpredictable power to the grid. Energy storage systems can be used to store energy while it is available for later use, thereby playing a significant role in the increased implementation of renewable energy. Increased usage of energy storage systems can also prevent congestion in transmission lines which if severe enough could cause blackouts