scholarly journals Optimal Operation of Building Microgrids with Rooftop Greenhouse Under Component Outages in Islanded Mode

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1930
Author(s):  
Se-Hyeok Choi ◽  
Akhtar Hussain ◽  
Hak-Man Kim
Keyword(s):  
Numerical Simulation ◽  
Optimal Operation ◽  
Weight Matrix ◽  
Normal Operation ◽  
Control Parameters ◽  
Available Energy ◽  
Local Resources ◽  
Islanded Mode ◽  
Simulation Results ◽  
And Control

An optimal operation scheme for a building microgrid with a rooftop greenhouse in islanded mode is proposed in this paper. In islanded mode, the fulfillment of entire demand is challenging due to the absence of connection with the utility grid and the scarcity of local resources. The situation becomes more challenging when one or more pieces of equipment fail during the islanded mode. Therefore, in addition to islanded mode operation, component outage and recovery are also considered in this paper. In order to use the available energy efficiently, prioritization of building loads and control parameters of the greenhouse are proposed. A priority weight matrix is adopted to decide the supply of energy to fulfill the requirements of control parameters in the case of insufficient energy. In addition to the normal operation bounds, new bounds are defined to operate the control parameters if the resources are not sufficient. Additional penalties are imposed if the new bounds are chosen, due to violation of the normal operation range. The microgrid system is rescheduled if any component outage or recovery is detected from the outage point to the end of the scheduling horizon. The performance of the proposed method is evaluated by carrying out several simulations including component outage, component recovery, and simultaneous outage of two or more types of equipment. Numerical simulation results have demonstrated the effectiveness of the proposed operation scheme for optimal operation of building microgrids with a rooftop greenhouse in islanded mode.

Numerical Simulation of Slope Excavation in Highway Renovation and Expansion Project

2014 ◽  
Vol 580-583 ◽  
pp. 827-830
Author(s):  
Gen Chuan Luo ◽  
Zhong Ming He ◽  
Xin Luo ◽  
Qing Guo Hu
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Stress And Strain ◽  
Regular Pattern ◽  
Expansion Process ◽  
Excavation Process ◽  
Slope Excavation ◽  
Object Use ◽  
Simulation Results ◽  
And Control

Slope stability analysis requires detect and control the stress and strain timely. Familiar with the slope‘s stress and strain changes in excavation process has important guiding significance for the actual construction. In this paper, choose a slope in Guangxi freeway renovation and expansion process as the research object. Use FLAC3D to analysis the stress and displacement simulation results of this slope excavation step by step. Summarize the excavation regular pattern.

scholarly journals Numerical Simulation and Experimental Study on Shaped Charge Warhead of Guided Ammunition

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Guangsong Ma ◽  
Guanglin He
Keyword(s):  
Numerical Simulation ◽  
Cone Angle ◽  
Shaped Charge ◽  
Liner Material ◽  
Penetration Ability ◽  
Simulation And Experiment ◽  
Control Section ◽  
Simulation Results ◽  
And Control ◽  
Shaped Charge Jet

To study the jet penetration capability of shaped charge warhead of guided ammunition, a variable cone angle-shaped charge liner was designed. LS-DYNA software is used to simulate the penetration capability of shaped charge warhead with three different metal materials (copper, steel, and aluminum). Numerical simulation results show that the velocity of the shaped charge jet formed by the three kinds of materials is v aluminum > v copper > v steel , and the residual velocity after penetration is V steel > V aluminum > V copper , the time when the jet starts to break is tcopper > tsteel > taluminum, and the penetration completion time is Tcopper < Taluminum < Tsteel; therefore, according to the numerical simulation results, copper was selected as the liner material, and the principle prototype is made for the experiment. The results of numerical simulation and experiment show that the shaped charge warhead with copper shaped charge liner has good penetration ability and after-effect damage ability to steel target after penetrating the guidance section, steering gear section, and control section.

scholarly journals Multi-chain Fudan-CCDC model for COVID-19 – a revisit to Singapore’s case

2020 ◽  
Author(s):  
Hanshuang Pan ◽  
Nian Shao ◽  
Yue Yan ◽  
Xinyue Luo ◽  
Shufen Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Penalty Function ◽  
Prevention And Control ◽  
World Wide ◽  
Data Fitting ◽  
Chain Model ◽  
Single Chain ◽  
Simulation Results ◽  
Different Characteristics ◽  
And Control

AbstractBackgroundCOVID-19 has been impacting on the whole world critically and constantly since late December 2019. Rapidly increasing infections has raised intense world-wide attention. How to model the evolution of COVID-19 effectively and efficiently is of great significance for prevention and control.MethodsWe propose the multi-chain Fudan-CCDC model based on the original single-chain model in [8] to describe the evolution of COVID-19 in Singapore. Multi-chains can be considered as the superposition of several single chains with different characteristics. We identify parameters of models by minimizing the penalty function.ResultsThe numerical simulation results exhibit the multichain model performs well on data fitting. Though unsteady the increments are, they could still fall within the range of ±25% fluctuation from simulation results. It is predicted by multi-chain models that Singapore are experiencing a nonnegligible risk of explosive outbreak, thus stronger measures are urgently needed to contain the epidemic.ConclusionThe multi-chain Fudan-CCDC model provides an effective way to early detect the appearance of imported infectors and super spreaders and forecast a second outbreak. It can also explain the data in those countries where the single-chain model shows deviation from the data.

scholarly journals On modelling and control design for self-balanced two-wheel vehicle

2008 ◽  
Vol 30 (3) ◽  
Author(s):  
Nguyen Hoang Quang
Keyword(s):  
Numerical Simulation ◽  
Differential Equations ◽  
Mobile Robot ◽  
Equations Of Motion ◽  
Control Design ◽  
Modeling And Control ◽  
Linearized Equations ◽  
Stable Motion ◽  
Simulation Results ◽  
And Control

In this paper, the modeling and control design of a self-balancing mobile robot are presented. The method of sub-structures is employed to derive the differential equations of motion of the robot. Based on the linearized equations of motion, a controller is designed to maintain a stable motion of the robot. Some numerical simulation results are shown to clarify the designed controller.

NONLINEAR BEHAVIORS OF GEAR SHIFTING DIGITAL PHASE LOCKED LOOPS

2012 ◽  
Vol 22 (08) ◽  
pp. 1250204 ◽  
Author(s):  
XI CHEN ◽  
BINGO WING-KUEN LING ◽  
LI-MIN SUN
Keyword(s):  
Numerical Simulation ◽  
Adaptive Control ◽  
Steady State ◽  
Initial Conditions ◽  
Phase Locked Loops ◽  
Control Parameters ◽  
Dynamical Behaviors ◽  
Digital Phase Locked Loops ◽  
Simulation Results ◽  
Nonlinear Behaviors

Applying gear shifting algorithms to the implementation of Phase Locked Loops (PLLs) can significantly improve their performances. However, the behaviors of gear shifting digital PLLs (GSDPLLs) have not been fully studied due to the existence of newly adaptive control parameters. These parameters play a very important role in the design of GSDPLLs. In this paper, various nonlinear behaviors of GSDPLLs including the steady state periodic behaviors, divergent behaviors and chaotic behaviors, are studied. In particular, the effects of the initial conditions of GSDPLLs on their dynamical behaviors are investigated. The obtained results are useful for the design of GSDPLLs. Numerical simulation results are presented for illustrations.

scholarly journals Control and Optimization of Network in Networked Control System

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Wang Zhiwen ◽  
Sun Hongtao
Keyword(s):  
Numerical Simulation ◽  
Linear Time ◽  
Networked Control System ◽  
Network Congestion ◽  
Linear Quadratic ◽  
Linear Time Invariant ◽  
Simulation Results ◽  
And Control ◽  
Time Invariant

In order to avoid quality of performance (QoP) degradation resulting from quality of service (QoS), the solution to network congestion from the point of control theory, which marks departure of our results from the existing methods, is proposed in this paper. The congestion and bandwidth are regarded as state and control variables, respectively; then, the linear time-invariant (LTI) model between congestion state and bandwidth of network is established. Consequently, linear quadratic method is used to eliminate the network congestion by allocating bandwidth dynamically. At last, numerical simulation results are given to illustrate the effectiveness of this modeling approach.

Investigations on the effects of obstacles on the surfaces of blades of the centrifugal pump to suppress cavitation development

2021 ◽  
pp. 2150327
Author(s):  
Weiguo Zhao ◽  
Bao Guo
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Centrifugal Pump ◽  
Cavitation Flow ◽  
Cavitation Model ◽  
Cavitation Performance ◽  
Simulation Results ◽  
Specific Speed ◽  
And Control ◽  
Good Agreement

This paper proposes a new method that obstacles are attached to both the suction and pressure surfaces of the blades to suppress cavitation development. A centrifugal pump with a specific speed of 32 is selected as the physical model to perform the external characteristic and cavitation performance experiments. SST [Formula: see text] turbulence model and Zwart cavitation model were employed to simulate the unsteady cavitation flow in the pump. The results indicate that the numerical simulation results are in good agreement with the experimental counterparts. After the obstacles are arranged, the maximum head decrease is only 1.37%, and the relative maximum drop of efficiency is 1.12%. Obstacles have minimal impacts on the variations of head and efficiency under all flow rate conditions. The distribution of vapor volume in the centrifugal pump is significantly reduced after obstacles are arranged and the maximum fraction reduction is 53.6%. The amplitude of blade passing frequency decreases significantly. While obstacles decrease the intensity of turbulent kinetic energy near the wall in the impeller passages to effectively reduce the distribution of cavitation bubbles, and control the development of cavitation. After the obstacles are set, the strength of the vortex in the impeller passages is weakened significantly, the shedding of the vortex is suppressed, flow in the impeller becomes more stable.

scholarly journals Optimal Operation of Networked Microgrids for Enhancing Resilience Using Mobile Electric Vehicles

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 142
Author(s):  
Asfand Yar Ali ◽  
Akhtar Hussain ◽  
Ju-Won Baek ◽  
Hak-Man Kim
Keyword(s):  
Power Systems ◽  
Electric Vehicles ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Optimal Operation ◽  
Available Energy ◽  
Local Resources ◽  
Islanded Microgrid ◽  
Absence Of Power ◽  
Networked Microgrids

The increased intensity and frequency of natural disasters have attracted the attention of researchers in the power sector to enhance the resilience of power systems. Microgrids are considered as a potential solution to enhance the resilience of power systems using local resources, such as renewable energy sources, electric vehicles (EV), and energy storage systems. However, the deployment of an additional storage system for resilience can increase the investment cost. Therefore, in this study, the usage of existing EVs in microgrids is proposed as a solution to increase the resilience of microgrids with outages without the need for additional investment. In the case of contingencies, the proposed algorithm supplies energy to islanded microgrids from grid-connected microgrids by using mobile EVs. The process for the selection of EVs for supplying energy to islanded microgrids is carried out in three steps. Firstly, islanded and networked microgrids inform the central energy management system (CEMS) about the required and available energy stored in EVs, respectively. Secondly, CEMS determines the microgrids among networked microgrids to supply energy to the islanded microgrid. Finally, the selected microgrids determine the EVs for supplying energy to the islanded microgrid. Simulations have shown the effectiveness of the proposed algorithm in enhancing the resilience of microgrids even in the absence of power connection among microgrids.

Probability model for control parameters in the aircraft's information and control systems

2018 ◽  
Vol 2 ◽  
pp. 9-16
Author(s):  
A. Al-Ammouri ◽  
◽  
H.A. Al-Ammori ◽  
A.E. Klochan ◽  
A.M. Al-Akhmad ◽  
...  
Keyword(s):  
Control Systems ◽  
Probability Model ◽  
Control Parameters ◽  
And Control

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results
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