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.

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.

A sketch drawing humanoid robot using image-based visual servoing

2019 ◽  
Vol 34 ◽  
Author(s):  
Meng-Cheng Lau ◽  
John Anderson ◽  
Jacky Baltes
Keyword(s):  
Error Correction ◽  
Visual Servoing ◽  
Humanoid Robot ◽  
Closed Loop ◽  
Open Loop ◽  
Experimental Results ◽  
Drawing Process ◽  
Open Loop Control ◽  
Loop Control ◽  
Error Correction Capability

Abstract This paper presents our sketch drawing artist humanoid robot research. One of the limitations of the existing artist humanoid robot is the lack of feedback on the error that occurs during the drawing process. The contribution of this research is the development of a humanoid robot artist with drawing error correction capability. Based on our previous work with open-loop control pen-and-ink humanoid robot artist, we have implemented a closed-loop visual servoing approach to address this problem. Our experimental results show that this approach is sufficient to correct drawing errors that occur due to mechanical limitation of a robot.

Dynamic Coefficients of a Tilting Pad With Active Lubrication: Comparison Between Theoretical and Experimental Results

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Alejandro Cerda Varela ◽  
Ilmar Ferreira Santos
Keyword(s):  
Mathematical Model ◽  
Closed Loop ◽  
Open Loop ◽  
Control Signal ◽  
Experimental Results ◽  
Industrial Grade ◽  
Tilting Pad ◽  
Oil Flow ◽  
Bearing Design ◽  
The Mathematical Model

This paper deals with the validation of the mathematical model for predicting the equivalent stiffness and damping of an active tilting-pad bearing. The active bearing design includes an injection nozzle in the pad and a hydraulic supply system featuring a servovalve, which enables to modify the pressurized oil flow into the bearing clearance. The servovalve is governed by a control signal, obtained in open- or closed-loop configuration. The mathematical model includes the dynamics related to journal, tilting pads, and associated hydraulic system. First, the model results are tested against experimental results from the literature for industrial grade passive tilting pad bearings. This initial validation is followed by a comparison with experimental identification results obtained from a test rig featuring the active bearing design. Good overall agreement is observed in both configurations. The results provide an overview about the feasibility of modifying the bearing impedance by means of the active lubrication system, both in open-loop (fixed control signal), or closed-loop, as a function of the journal position and proportional derivative (PD) controller gains.

scholarly journals Experimental and Simulation Modal Analysis of a Prismatic Battery Module

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2046 ◽  
Author(s):  
Bizhong Xia ◽  
Fan Liu ◽  
Chao Xu ◽  
Yifan Liu ◽  
Yongzhi Lai ◽  
...  
Keyword(s):  
Modal Analysis ◽  
Excitation Frequency ◽  
Experimental Results ◽  
Battery Pack ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Average Error ◽  
Clear Understanding ◽  
The Impact ◽  
Battery Module

The battery pack is the core component of a new energy vehicle (NEV), and reducing the impact of vibration induced resonance from the ground is a prerequisite for the safety of an NEV. For a high-performance battery pack design, a clear understanding of the structural dynamics of the key part of battery pack, such as the battery module, is of great significance. Additionally, a proper computational model for simulations of battery module also plays a key role in correctly predicting the dynamic response of battery packs. In this paper, an experimental modal analysis (EMA) was performed on a typical commercial battery module, composed of twelve 37Ah lithium nickel manganese cobalt oxide (NMC) prismatic cells, to obtain modal parameters such as mode shapes and natural frequencies. Additionally, three modeling methods for a prismatic battery module were established for the simulation modal analysis. The method of simplifying the prismatic cell to homogenous isotropic material had a better performance than the detailed modeling method, in predicting the modal parameters. Simultaneously, a novel method that can quickly obtain the equivalent parameters of the cell was proposed. The experimental results indicated that the fundamental frequency of battery module was higher than the excitation frequency range (0–150 Hz) from the ground. The mode shapes of the simulation results were in good agreement with the experimental results, and the average error of the natural frequency was below 10%, which verified the validity of the numerical model.

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.

scholarly journals Lithium-Ion Polymer Battery for 12-Voltage Applications: Experiment, Modelling, and Validation

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 638
Author(s):  
Yiqun Liu ◽  
Y. Gene Liao ◽  
Ming-Chia Lai
Keyword(s):  
Energy Storage ◽  
Electric Energy ◽  
Lithium Ion ◽  
Experimental Tests ◽  
Design Guidelines ◽  
Battery Pack ◽  
Battery Cell ◽  
Electric Energy Storage ◽  
Energy Storage Applications ◽  
Battery Module

Modelling, simulation, and validation of the 12-volt battery pack using a 20 Ah lithium–nickel–manganese–cobalt–oxide cell is presented in this paper. The cell characteristics influenced by thermal effects are also considered in the modelling. The parameters normalized directly from a single cell experiment are foundations of the model. This approach provides a systematic integration of actual cell monitoring with a module model that contains four cells connected in series. The validated battery module model then is utilized to form a high fidelity 80 Ah 12-volt battery pack with 14.4 V nominal voltage. The battery cell thermal effectiveness and battery module management system functions are constructed in the MATLAB/Simulink platform. The experimental tests are carried out in an industry-scale setup with cycler unit, temperature control chamber, and computer-controlled software for battery testing. As the 12-volt lithium-ion battery packs might be ready for mainstream adoption in automotive starting–lighting–ignition (SLI), stop–start engine idling elimination, and stationary energy storage applications, this paper investigates the influence of ambient temperature and charging/discharging currents on the battery performance in terms of discharging voltage and usable capacity. The proposed simulation model provides design guidelines for lithium-ion polymer batteries in electrified vehicles and stationary electric energy storage applications.

scholarly journals Control of a gantry crane using input-shaping schemes with distributed delay

2016 ◽  
Vol 39 (3) ◽  
pp. 361-370 ◽  
Author(s):  
MJ Maghsoudi ◽  
Z Mohamed ◽  
MO Tokhi ◽  
AR Husain ◽  
MSZ Abidin
Keyword(s):  
Real Time ◽  
Closed Loop ◽  
Distributed Delay ◽  
Performance Comparison ◽  
Open Loop ◽  
Experimental Results ◽  
Gantry Crane ◽  
Input Shaping ◽  
Position Response ◽  
Sway Frequency

This paper presents simulation and real-time implementation of input-shaping schemes with a distributed delay for control of a gantry crane. Both open-loop and closed-loop input-shaping schemes are considered. Zero vibration and zero vibration derivative input shapers are designed for performance comparison in terms of trolley position response and level of sway reduction. Simulation and experimental results have shown that all the shapers are able to reduce payload sway significantly while maintaining satisfactory position response. Investigations with different cable lengths that correspond to ±20% changes in the sway frequency have shown the distributed delay-based shaper has asymmetric robustness behaviour. The shaper provides highest robustness for the case of 20% increase in the sway frequency but lower robustness for the case of 20% decrease. However, other schemes give symmetric robustness behaviour for both cases.

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.

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