Production of MgO From Residues of Saline Pools in “Las Coloradas” Yucatan, Mex. Using Thermochemical Energy Storage

2011 ◽  
Author(s):  
Jose Carlos Peraza Lizama ◽  
Carlos Martin Rubio Atoche ◽  
Alan Garcia Lira
Keyword(s):  
Energy Storage ◽  
Magnesium Oxide ◽  
Electricity Generation ◽  
Closed Loop ◽  
Sea Water ◽  
High Heat ◽  
Open Loop ◽  
Salt Ponds ◽  
Heat Of Decomposition ◽  
Iodine Reaction

This paper proposes a method of thermochemical-energy storage from magnesium sulfate recovered from salt ponds of sea water. The idea develops from a project originally thought to obtain magnesium oxide from a salt plant in the Yucatan Peninsula, Mexico. The new idea is based on the exploitation of the heat of decomposition of magnesium sulphate. In the traditional literature, closed-loop, reversible reaction is considered, whereas in this work, an open-loop is proposed; that is, sulphur dioxide is separated from the magnesium oxide before cooling down to 700°C; in this way, magnesium oxide is obtained by thermal decomposition, and at the same time, the high heat of decomposition is used to store thermal energy for electricity generation; magnesium oxide, sulfuric acid and hydrogen are co-products of the process if another iodine reaction cycle is considered. This second process is again a modification of an open-loop traditional process, to a closed-loop process where no sulphuric acid is required.

Design of Materials and Mechanisms for Responsive Robots

2018 ◽  
Vol 1 (1) ◽  
pp. 359-384 ◽  
Author(s):  
Elliot W. Hawkes ◽  
Mark R. Cutkosky
Keyword(s):  
Genetic Algorithms ◽  
Energy Storage ◽  
Environmental Conditions ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Open Loop ◽  
Challenging Problem ◽  
Manufacturing Applications ◽  
The Stability ◽  
And Control

As robots move beyond manufacturing applications to less predictable environments, they can increasingly benefit, as animals do, from integrating sensing and control with the passive properties provided by particular combinations and arrangements of materials and mechanisms. This realization is partly responsible for the recent proliferation of soft and bioinspired robots. Tuned materials and mechanisms can provide several kinds of benefits, including energy storage and recovery, increased physical robustness, and decreased response time to sudden events. In addition, they may offer passive open-loop behaviors and responses to external changes in loading or environmental conditions. Collectively, these properties can also increase the stability of a robot as it interacts with the environment and allow the closed-loop controller to reduce the apparent degrees of freedom subject to control. The design of appropriate materials and mechanisms remains a challenging problem; bioinspiration, genetic algorithms, and numerical shape and materials optimization are all applicable. New multimaterial fabrication processes are also steadily increasing the range and magnitude of passive properties available for intrinsically responsive robots.

scholarly journals Autonomous Demand-Side Current Scheduling of Parallel Buck Regulated Battery Modules

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2095
Author(s):  
Yunfeng Jiang ◽  
Louis J. Shrinkle ◽  
Raymond A. de Callafon
Keyword(s):  
Energy Storage ◽  
Closed Loop ◽  
Open Circuit ◽  
Open Loop ◽  
Experimental Results ◽  
Battery Pack ◽  
Loop Scheduling ◽  
Load Impedance ◽  
Internal Impedance ◽  
Battery Module

This paper presents the algorithms, hardware overview and testing results for controlling discharge currents from mixed battery modules placed in a parallel configuration. Battery modules with different open-circuit voltage (OCV), internal impedance or even state of charge (SOC) between modules are usually used to form a battery pack. Parallel placed mixed battery modules are typically seen in second-life, repurposed or exchangeable battery systems to increase power and energy storage capacity of a battery pack in mobile, electric vehicle (EV) and stationary energy storage application. This paper addresses battery module heterogeneity by taking advantage of buck regulators on each battery module and formulating scheduling algorithms to dispatch the buck regulators to balance the current out of each battery module. In this way, mixed battery modules can be combined and coordinated to provide a balanced power flow and guarantee safety of the total battery pack. Both open-loop and closed-loop scheduling of buck regulated battery modules are analyzed in this paper. In the open-loop algorithm, buck regulator dispatch commands are computed based on full knowledge of the OCV and impedance of each battery module, while monitoring the load impedance. In the closed-loop algorithm, dispatch commands are generated automatically by a digital proportional-integral-derivative (PID) feedback controller for which battery module current reference signals are computed recursively while monitoring the load impedance. The closed-loop scheduling method is also validated through experimental work that simulates a battery pack with several parallel placed buck regulated battery modules. The experimental results illustrate that the current from each battery module can be rated based on the SOC of each module and that the current remains balanced, despite discrepancies between OCV and internal impedance between modules. The experimental results show that the closed-loop algorithm allows scheduling of buck regulated battery modules, even in the absence of knowledge on the variations of OCV and impedance between battery modules.

Reliability Challenges in Design and Operation of High Heat Powered Processors

2005 ◽  
Author(s):  
Ali Heydari ◽  
Vadim Gektin
Keyword(s):  
Heat Flux ◽  
Closed Loop ◽  
Heat Removal ◽  
High Heat ◽  
Electrical Signal ◽  
Open Loop ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Air Cooling ◽  
Interconnect Design

Advances in processor design have been made possible in part by increases in the packaging density of electronics. At the same time, combination of increased power dissipation and packaging density has led to substantial growth in the chip and system heat fluxes and amplified complexity in electrical signal integrity and mechanical stack-up design in the recent years, particularly, in the high-end computers. With the trend towards miniaturization, heat removal, along with increased reliability requirements, has become a major bottleneck in product development, especially, in low profile systems, telecom servers and blades. Cooling of high heat flux components may require consideration of innovative open-loop, as well as plausible closed-loop, cooling designs for data centers. This paper addresses reliability aspects of thermal, electrical, mechanical, and interconnect design and long-life operation of high-end air-cooling, as well as feasible active open and closed-loop cooling technologies of high heat flux processors.

scholarly journals Analysis of Dynamic Characteristics of a 600 kW Storage Type Wind Turbine with Hybrid Hydraulic Transmission

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 397 ◽  
Author(s):  
Zengguang Liu ◽  
Yanhua Tao ◽  
Liejiang Wei ◽  
Peng Zhan ◽  
Daling Yue
Keyword(s):  
Power Generation ◽  
Energy Storage ◽  
Wind Energy ◽  
Wind Turbine ◽  
Closed Loop ◽  
Control Method ◽  
Open Loop ◽  
Wheel Speed ◽  
Loop Control ◽  
Storage Type

In order to improve the efficiency and convenience of wind energy storage and solve the reproducibility of the hydraulic wind turbine, we present a storage type wind turbine with an innovative hybrid hydraulic transmission, which was adopted in the development of a 600 kW storage type wind turbine experimental platform. The whole hydraulic system of the storage type wind turbine is mainly an ingenious combination of a closed loop transmission and an open loop one, which can also be divided into three parts: hydraulic variable speed, hydraulic energy storage, power generation. For the study focusing on the capture and storage of wind energy, the mathematical model of the wind turbine except for the power generation was established under MATLAB/Simulink. A double closed loop control strategy is proposed to achieve the wind wheel speed regulation and wind energy storage. The dynamic simulations of the 600 kW storage type wind turbine experimental prototype were carried out under two different input signals. The results show that the wind wheel speed achieves the desired value at fast response and high precision using the control method given in this paper, and the proposed new storage type wind turbine is reasonable and practical.

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

Trust is Good, Control is Better: A Review on Monitoring and Characterization Techniques for Flow Battery Electrolytes

2021 ◽  
Author(s):  
Ulrich Sigmar Schubert ◽  
Oliver Nolte ◽  
Ivan Volodin ◽  
Christian Stolze ◽  
Martin D. Hager
Keyword(s):  
Energy Storage ◽  
Electricity Generation ◽  
Large Scale ◽  
Good Control ◽  
Renewable Electricity ◽  
Flow Battery ◽  
Large Share ◽  
Characterization Techniques ◽  
Renewable Electricity Generation ◽  
Storage Technologies

Flow Batteries (FBs) currently are one of the most promising large-scale energy storage technologies for energy grids with a large share of renewable electricity generation. Among the main technological challenges...

scholarly journals Parallel Point Clouds: Hybrid Point Cloud Generation and 3D Model Enhancement via Virtual–Real Integration

2021 ◽  
Vol 13 (15) ◽  
pp. 2868
Author(s):  
Yonglin Tian ◽  
Xiao Wang ◽  
Yu Shen ◽  
Zhongzheng Guo ◽  
Zilei Wang ◽  
...  
Keyword(s):  
Point Cloud ◽  
Closed Loop ◽  
Real Data ◽  
Point Clouds ◽  
Autonomous Driving ◽  
Training Model ◽  
Labor Cost ◽  
Open Loop ◽  
Training Dataset ◽  
Data Annotation

Three-dimensional information perception from point clouds is of vital importance for improving the ability of machines to understand the world, especially for autonomous driving and unmanned aerial vehicles. Data annotation for point clouds is one of the most challenging and costly tasks. In this paper, we propose a closed-loop and virtual–real interactive point cloud generation and model-upgrading framework called Parallel Point Clouds (PPCs). To our best knowledge, this is the first time that the training model has been changed from an open-loop to a closed-loop mechanism. The feedback from the evaluation results is used to update the training dataset, benefiting from the flexibility of artificial scenes. Under the framework, a point-based LiDAR simulation model is proposed, which greatly simplifies the scanning operation. Besides, a group-based placing method is put forward to integrate hybrid point clouds, via locating candidate positions for virtual objects in real scenes. Taking advantage of the CAD models and mobile LiDAR devices, two hybrid point cloud datasets, i.e., ShapeKITTI and MobilePointClouds, are built for 3D detection tasks. With almost zero labor cost on data annotation for newly added objects, the models (PointPillars) trained with ShapeKITTI and MobilePointClouds achieved 78.6% and 60.0% of the average precision of the model trained with real data on 3D detection, respectively.

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