scholarly journals Simulation and Experimental Research on the Disturbance Behavior of a Sun-Tracking Solar Array Driven by a Stepping Motor

2021 ◽  
Vol 11 (19) ◽  
pp. 9076
Author(s):  
Jisong Yu ◽  
Yongliang Guan ◽  
Daowei Zhang ◽  
Shanbo Chen ◽  
Chunjuan Zhao ◽  
...  
Keyword(s):  
Energy Demand ◽  
Optimization Design ◽  
Vibration Suppression ◽  
System Optimization ◽  
Solar Array ◽  
Frequency Error ◽  
The Sun ◽  
Proposed Model ◽  
Micro Vibration ◽  
Disturbance Torque

A sun-tracking solar array is an effective solution to the increasing energy demand of spacecrafts. However, the driving torque fluctuation of the solar array driving assembly (SADA) and its oscillatory motion lead to the micro-vibration problem of the spacecraft. In this article, a disturbance torque model of the sun-tracking solar array, which takes its friction and flexibility into consideration, is established. Furthermore, a test platform was built to measure the disturbance force/torque, and a solar array simulator (SAS) was designed to replace the solar array in the ground experiments. Finally, the disturbance torque of the SADA-driven SAS is simulated, and the model is validated by comparing the simulation results with the experimental results. These results show that the frequency error of the model is less than 0.648%, and the amplitude error of the corresponding frequency is less than 22.33%, which indicates that the proposed model can effectively predict the disturbance torque generated by the sun-tracking solar array in orbit. The research provides theoretical guidance for the system optimization design and micro-vibration suppression of spacecrafts.

scholarly journals Usage of the Pareto Fronts as a Tool to Select Data in the Forecasting Process—A Short-Term Electric Energy Demand Forecasting Case

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3204
Author(s):  
Michał Sabat ◽  
Dariusz Baczyński
Keyword(s):  
Energy Demand ◽  
Demand Forecasting ◽  
Electric Energy ◽  
Forecasting Model ◽  
Short Term ◽  
Complex Evaluation ◽  
Proposed Model ◽  
Energy Demand Forecasting ◽  
Pareto Fronts ◽  
Naive Approach

Transmission, distribution, and micro-grid system operators are struggling with the increasing number of renewables and the changing nature of energy demand. This necessitates the use of prognostic methods based on ever shorter time series. This study depicted an attempt to develop an appropriate method by introducing a novel forecasting model based on the idea to use the Pareto fronts as a tool to select data in the forecasting process. The proposed model was implemented to forecast short-term electric energy demand in Poland using historical hourly demand values from Polish TSO. The study rather intended on implementing the range of different approaches—scenarios of Pareto fronts usage than on a complex evaluation of the obtained results. However, performance of proposed models was compared with a few benchmark forecasting models, including naïve approach, SARIMAX, kNN, and regression. For two scenarios, it has outperformed all other models by minimum 7.7%.

Dynamic Modeling for a Flexible Spacecraft With Solar Arrays Composed of Honeycomb Panels and Its Proportional–Derivative Control With Input Shaper

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Lun Liu ◽  
Dengqing Cao
Keyword(s):  
Dynamic Model ◽  
Vibration Suppression ◽  
Hybrid Control ◽  
Flexible Spacecraft ◽  
Solar Array ◽  
Pd Controller ◽  
Pd Control ◽  
Solar Arrays ◽  
Attitude Maneuver ◽  
The One

A high-precision dynamic model of a flexible spacecraft installed with solar arrays, which are composed of honeycomb panels, is established based on the nonconstrained modes of flexible appendages (solar arrays), and an effective cooperative controller is designed for attitude maneuver and vibration suppression by integrating the proportional–derivative (PD) control and input shaping (IS) technique. The governing motion equations of the system and the corresponding boundary conditions are derived by using Hamiltonian Principle. Solving the linearized form of those equations with associated boundaries, the nonconstrained modes of solar arrays are obtained for deriving the discretized dynamic model. Applying this discretized model and combining the IS technique with the PD controller, a hybrid control scheme is designed to achieve the attitude maneuver of the spacecraft and vibration suppression of its flexible solar arrays. The numerical results reveal that the nonconstrained modes of the system are significantly influenced by the spacecraft flexibility and honeycomb panel parameters. Meanwhile, the differences between the nonconstrained modes and the constrained ones are growing as the spacecraft flexibility increases. Compared with the pure PD controller, the one integrating the PD control and IS technique performs much better, because it is more effective for suppressing the oscillation of attitude angular velocity and the vibration of solar array during the attitude maneuver, and reducing the residual vibration after the maneuver process.

Active Monitoring, Machinery Example

2012 ◽  
pp. 217-231
Keyword(s):  
Knowledge Creation ◽  
Optimization Design ◽  
System Optimization ◽  
Technical System ◽  
System State ◽  
Source Information ◽  
Active Monitoring ◽  
Intentional Activities ◽  
Rational Evaluation ◽  
Design Construction

Active machinery monitoring – continuous supervising, diagnosing, managing, controlling, compensating, documenting- is a process of acquiring and transferring streams of information (usually source information) about the analysed object, process, and relations between the same and the environment that can be used to realize the postulated state: knowledge creation (theory and innovation), environment melioration (harmfulness) and technical system optimization (design) - depending on technology needs and engineer imaginations. Knowledge creation comes as result of the creative action (creating). Melioration means the intentional activities of a technical system and boundary zone; activities that enhance, improve, and restore properties of the environment and not only limit technological harmfulness. Optimum comes in property of the machinery design (construction) or system state with respect to the criteria that enable rational evaluation of the state. Active monitoring, investigations into multi-disc grinders, demonstrate that it is possible to acquire knowledge of, describe and utilize, for design and structural purposes, the characteristics that indicate the relations between speeds, idle movement, loads and the indicators of motion variables in the grinding space. The objective of this example is to provide a mathematical description, optimisation of the states and changes in the grinding grains and machine space, their surface and volume during movement (idle and working movement) of the components, and design assemblies in the multi-hole grinding process.

Synchronized Operation of Grid Power, Solar Power, and Battery for Smart Energy Management

2018 ◽  
pp. 255-291 ◽  
Author(s):  
Pawan Kumar ◽  
Dip V. Thanki
Keyword(s):  
Energy Demand ◽  
Solar Array ◽  
Solar Arrays ◽  
Load Demand ◽  
Perturb And Observe ◽  
Smart Energy Management ◽  
Site Evaluation ◽  
Pros And Cons ◽  
Solar Powered ◽  
Power Point

This chapter gives details of solar photovoltaic, starting from its general pros and cons. It covers the basics of site evaluation when installing a solar powered plant and various ways to overcome the uncertainties in the predicted output of the solar arrays. The efficiency of the plant can be improved with the help of maximum power point tracker (MPPT), which works on algorithms based on perturb and observe, incremental conductance, constant voltage, etc. The output of the solar PV arrays can be utilized more effectively by integrating it with grid to supply ac loads. This integration requires a power conditioning system (PCS), enabling smooth operation. Continuity of supply can be maintained by having a battery backup, for the time when both grid and solar array fail to meet the load demand. Such a system can have wide range of applications and has the potential to meet the energy demand.

Synchronized Operation of Grid Power, Solar Power, and Battery for Smart Energy Management

2022 ◽  
pp. 1231-1267
Author(s):  
Pawan Kumar ◽  
Dip V. Thanki
Keyword(s):  
Energy Demand ◽  
Solar Array ◽  
Solar Arrays ◽  
Load Demand ◽  
Perturb And Observe ◽  
Smart Energy Management ◽  
Site Evaluation ◽  
Pros And Cons ◽  
Solar Powered ◽  
Power Point

This chapter gives details of solar photovoltaic, starting from its general pros and cons. It covers the basics of site evaluation when installing a solar powered plant and various ways to overcome the uncertainties in the predicted output of the solar arrays. The efficiency of the plant can be improved with the help of maximum power point tracker (MPPT), which works on algorithms based on perturb and observe, incremental conductance, constant voltage, etc. The output of the solar PV arrays can be utilized more effectively by integrating it with grid to supply ac loads. This integration requires a power conditioning system (PCS), enabling smooth operation. Continuity of supply can be maintained by having a battery backup, for the time when both grid and solar array fail to meet the load demand. Such a system can have wide range of applications and has the potential to meet the energy demand.

The Simulation Analysis of Tunnel Wind Cooling System in Shenyang Area

2013 ◽  
Vol 724-725 ◽  
pp. 1474-1477
Author(s):  
Xiao Ming Zhang ◽  
Yang Gao ◽  
Xiao Zhang
Keyword(s):  
Optimization Design ◽  
Simulation Analysis ◽  
Cooling System ◽  
System Optimization ◽  
Simulation Software ◽  
Equivalent Diameter ◽  
Tunnel Length ◽  
Surrounding Areas ◽  
Entrance Velocity ◽  
Tunnel Entrance

Applied FLUENT simulation software to research the influence of tunnel length, tunnel entrance velocity, tunnel equivalent diameter and tunnel buried depth four important factors on the tunnel wind cooling system in Shenyang area. The results show that, with the increase of tunnel length and tunnel buried depth and with the decrease of tunnel entrance velocity and tunnel equivalent diameter, the outdoor air which passed into the tunnel cooling amplitude increases. For the tunnel wind cooling system optimization design in Shenyang area and the surrounding areas, the advices are that tunnel buried depth should not be more than 6m and tunnel entrance velocity should not be more than 5m/s.

Structural Control of an Ultra-Large Semi-Submersible Floating Offshore Wind Turbine

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Zhixin Zhao ◽  
Wenhua Wang ◽  
Dongdong Han ◽  
Wei Shi ◽  
Yulin Si ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Structural Control ◽  
Degrees Of Freedom ◽  
Vibration Suppression ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Platform ◽  
Floating Offshore Wind Turbine ◽  
Proposed Model

Abstract A braceless semi-submersible floating platform is proposed for a Technical University of Denmark (DTU) 10-MW wind turbine at moderate water depths with reference to an existing National Renewable Energy Laboratory (NREL) 5-MW braceless semi-submersible floating platform, and a servo control system for a 10-MW semi-submersible floating offshore wind turbine (FOWT) is introduced. To control the ultimate and fatigue loads of the FOWT, a fore-aft tuned mass damper (TMD) installed in the nacelle of the 10-MW semi-submersible FOWT was investigated for vibration alleviation and load reduction. Considering the hydrodynamic and mooring effect, a four degrees-of-freedom (DOFs) (platform surge and pitch motions, tower fore-aft bending, and TMD translation) simplified dynamic model for the 10-MW semi-submersible FOWT is established based on D’Alembert’s principle. Then, the parameter estimation is conducted based on the Levenberg–Marquardt (LM) algorithm, and the simplified dynamic model was further verified by comparing the output responses with FAST and the proposed model. Furthermore, the exhaustive search (ES) and genetic algorithm (GA) are embedded into the simplified dynamic model to optimize the TMD parameters. Finally, a fully coupled time-domain simulation for all the selected environmental conditions is conducted in FAST, and the vibration suppression performance of the optimized TMD design for the 10-W semi-submersible FOWT was further examined and analyzed.

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