Toward a Unified Performance and Power Consumption NAND Flash Memory Model of Embedded and Solid State Secondary Storage Systems

This paper presents a set of models dedicated to describe a flash storage subsystem structure, functions, performance and power consumption behaviors. These models cover a large range of today's NAND flash memory applications. They are designed to be implemented in simulation tools allowing to estimate and compare performance and power consumption of I/O requests on flash memory based storage systems. Such tools can also help in designing and validating new flash storage systems and management mechanisms. This work is integrated in a global project aiming to build a framework simulating complex flash storage hierarchies for performance and power consumption analysis. This tool will be highly configurable and modular with various levels of usage complexity according to the required aim: from a software user point of view for simulating storage systems, to a developer point of view for designing, testing and validating new flash storage management systems

Evaluation of power generation operations in response to changes in surface water reservoir storage

We used a customized, river basin-based model of surface water rights to evaluate the response of power plants to drought via simulated changes in reservoir storage. Our methodology models surface water rights in 11 river basins in Texas using five cases: (1) storage decrease of existing capacity of 10%, (2) storage decrease of 50%, (3) complete elimination of storage, (4) storage increase of 10% (all at existing locations), and (5) construction of new reservoirs (at new locations) with a total increase in baseline reservoir capacity for power plant cooling of 9%. Using the Brazos River basin as a sample, we evaluated power generation operations in terms of reliability, resiliency, and vulnerability. As simulated water storage decreases, reliability generally decreases and resiliency and vulnerability remain relatively constant. All three metrics remain relatively constant with increasing reservoir storage, with the exception of one power plant. As reservoir storage changes at power plants, other water users in the basin are also affected. In general, decreasing water storage is beneficial to other water users in the basin, and increasing storage is detrimental for many other users. Our analysis reveals basin-wide and individual power plant-level impacts of changing reservoir storage, demonstrating a methodology for evaluation of the sustainability and feasibility of constructing new reservoir storage as a water and energy management approach.Mechanical Engineerin

Technologies

Energy technologies to meet the power requirements of future space missions are reviewed. Photovoltaic, solar dynamic, and solar thermal technologies are discussed along with techniques for energy storage and power management and distribution

Sizing and Energy Management of a Hybrid Locomotive Based on Flywheel and Accumulators

The French National Railways Company (SNCF) is interested in the design of a hybrid locomotive based on various storage devices (accumulator, flywheel, and ultracapacitor) and fed by a diesel generator. This paper particularly deals with the integration of a flywheel device as a storage element with a reduced-power diesel generator and accumulators on the hybrid locomotive. First, a power flow model of energy-storage elements (flywheel and accumulator) is developed to achieve the design of the whole traction system. Then, two energy-management strategies based on a frequency approach are proposed. The first strategy led us to a bad exploitation of the flywheel, whereas the second strategy provides an optimal sizing of the storage device. Finally, a comparative study of the proposed structure with a flywheel and the existing structure of the locomotive (diesel generator, accumulators, and ultracapacitors) is presented

An analysis of space power system masses

Various space electrical power system masses are analyzed with particular emphasis on the power management and distribution (PMAD) portion. The electrical power system (EPS) is divided into functional blocks: source, interconnection, storage, transmission, distribution, system control and load. The PMAD subsystem is defined as all the blocks between the source, storage and load, plus the power conditioning equipment required for the source, storage and load. The EPS mass of a wide range of spacecraft is then classified as source, storage or PMAD and tabulated in a database. The intent of the database is to serve as a reference source for PMAD masses of existing and in-design spacecraft. The PMAD masses in the database range from 40 kg/kW to 183 kg/kW across the spacecraft systems studied. Factors influencing the power system mass are identified. These include the total spacecraft power requirements, total amount of load capacity and physical size of the spacecraft. It is found that a new utility class of power systems, represented by Space Station Freedom, is evolving

Small-scale energy storage in a distributed future

With increasing interest in the co-location of energy supply and demand through distributed generation will there be any need for large-scale energy-storage schemes in the future provision of energy? Indeed, if the future of energy supply is small-scale why should this not also apply to energy storage? This paper will examine the current drive towards localised heat and power production and available options for storage of energy at the point of demand. The economics, practicality and impact of localised storage will be analysed along with the potential for energy efficiency measures and load management to reduce energy storage requirements at the small scale

“An Integer Programming Power Optimization in Storage Systems”

AbstractThis paper presents a linear integer programming framework for effective power management in storage systems. A sample memory system with different data banks is considered for optimal energy consumption during data operations by manipulating the data among banks. The memory bank four-level power state schemes, namely, active, stand-by, nap, and power down states, are included for superior power management of the storage system by formulating a linear integer optimization framework that includes plausible data manipulations, energy consumption levels, data migration, and compression options. The numerical results illustrate the efficiency of the proposed framework in terms of power management of storage systems with respect to available approaches with two-level power state operations

Modular converter system for low-cost off-grid energy storage using second life Li-ion batteries

Lithium ion batteries are promising for small off- grid energy storage applications in developing countries because of their high energy density and long life. However, costs are prohibitive. Instead, we consider 'used' Li-ion batteries for this application, finding experimentally that many discarded laptop cells, for example, still have good capacity and cycle life. In order to make safe and optimal use of such cells, we present a modular power management system using a separate power converter for every cell. This novel approach allows individual batteries to be used to their full capacity. The power converters operate in voltage droop control mode to provide easy charge balancing and implement a battery management system to estimate the capacity of each cell, as we demonstrate experimentally.Comment: Presented at IEEE GHTC Oct 10-14, 2014, Silicon Valle