scholarly journals Optimization Analysis on Layout of 220kV Outdoor Substation for Noise Control at the Boundary

2021 ◽  
Vol 271 ◽  
pp. 01011
Author(s):  
Lu Mengyao
Keyword(s):  
Optimization Design ◽  
Control Method ◽  
Simulation Analysis ◽  
Sound Field ◽  
Layout Optimization ◽  
Analysis Model ◽  
Noise Optimization ◽  
Distribution Rule ◽  
Before And After ◽  
Propagation Rule

The noise in substations has become one of the most concerning problems in the field of power grid. In this paper, the principle of substation layout optimization based on the maximum acoustic ray shielding method is established in the premise of the sound wave propagation rule in complicated air medium to meet the requirements of relevant national environmental standards for noise at the boundary of the substation. By establishing the acoustic simulation analysis model of the 220kV outdoor substation, the noise level at the boundary of the substation before and after the layout optimization is compared and analysed, and the distribution rule of the sound field inside and outside the substation is obtained. The analysis results show that the optimized layout of the substation can effectively reduce the noise at the boundary of the substation, which provides a control method for the noise optimization design of the substation.

scholarly journals Study on Sound Field Distribution Rule for Tank Structures of Large Oil-immersed Transformers

2021 ◽  
Vol 233 ◽  
pp. 01021
Author(s):  
Ma Yuchao ◽  
Mo Juan ◽  
Yu Jinshan ◽  
Li Xiang ◽  
Zheng Zhongyuan
Keyword(s):  
Power Systems ◽  
Field Distribution ◽  
Influence Factors ◽  
Sound Field ◽  
Noise Pollution ◽  
Sound Waves ◽  
Analysis Model ◽  
Term Operation ◽  
Distribution Rule ◽  
Propagation Rule

Large oil-immersed transformers are an important part of the transmission and distribution network in power systems. Power transformers are the main noise source of substations. Because of the uneven manufacturing process, aging equipment, long-term operation, and close distance from sensitive points, the problem of transformer noise pollution has become increasingly prominent. In this paper, the transmission and analysis model is established for transformer sound waves on the interface between insulating oil and tank body according to the sound wave propagation rule in complicated medium, and the simplified acoustic simulation model is constructed for large oil-immersed transformers by simulating the vibration noise of transformer core with monopole sound source, with which, the sound field distribution rule inside and outside the transformer tank structure is obtained, and finally, the influence factors for noise distribution are given. The results of the study provide control basis for reducing transformer noise.

scholarly journals A Review of the Flow-Induced Noise Study for Centrifugal Pumps

2020 ◽  
Vol 10 (3) ◽  
pp. 1022 ◽  
Author(s):  
Chang Guo ◽  
Ming Gao ◽  
Suoying He
Keyword(s):  
Optimization Design ◽  
Sound Field ◽  
Operating Conditions ◽  
Response Analysis ◽  
Centrifugal Pumps ◽  
Noise Optimization ◽  
Operating Stability ◽  
Study Results ◽  
Flow Induced Noise ◽  
Negative Impacts

Flow-induced noise is a significant concern for the design and operation of centrifugal pumps. The negative impacts of flow-induced noise on operating stability, human health and the environment have been shown in many cases. This paper presents a comprehensive review of the flow-induced noise study for centrifugal pumps to synthesize the current study status. First, the generation mechanism and propagation route of flow-induced noise are discussed. Then, three kinds of study methodologies, including the theoretical study of hydrodynamic noise, numerical simulation and experimental measurement study, are summarized. Subsequently, the application of the three study methodologies to the analysis of the distribution characteristics of flow-induced noise is analyzed from aspects of the noise source identification and comparison, the frequency response analysis, the directivity characteristics of sound field and the noise changing characteristics under various operating conditions. After that, the analysis of the noise optimization design of centrifugal pumps is summarized. Finally, based on previous study results, this paper puts forward the unsolved problems and implications for future study. In conclusion, the information collected in this review paper could guide further study of the flow-induced noise of centrifugal pumps.

Structure Sensitivity Analysis and Dynamic Performance Optimization of Marine Gearbox

2017 ◽  
Author(s):  
Tengjiao Lin ◽  
Daokun Xie ◽  
Ziran Tan ◽  
Bo Liu
Keyword(s):  
Sensitivity Analysis ◽  
Performance Optimization ◽  
Optimization Design ◽  
Dynamic Performance ◽  
Structure Sensitivity ◽  
Superposition Method ◽  
Structure Parameters ◽  
Analysis Model ◽  
Vibration Acceleration ◽  
Response Optimization

The aim of this paper is to investigate the influence of structure parameters on the vibration characteristics and improve the dynamic performance of marine gearbox. A finite element model was established to solve the dynamic response by using modal superposition method. Based on the theory of multi-objective optimization design, the structure sensitivity analysis model of marine gearbox was established, which takes the structure parameters of the housing as design variables. The modal and response sensitivity was obtained by using the optimal gradient method. According to the results of sensitivity analysis, a modal and response optimization model of marine gearbox was established. The objective was to avoid natural frequencies from the excitation frequencies and minimize the root mean square of vibration acceleration of the evaluating points on the surface of housing. Then the modal optimization and response optimization of gearbox were carried out by using zero-order and first-order optimization method. The results indicate that the dynamic optimization of the gearbox can be achieved. After optimization, the amplitude of vibration acceleration of the evaluating points on the housing surface has been reduced and the resonance of marine gearbox can be avoided.

scholarly journals Motor shifting and torque distribution control of a multi-motor driving system in electric construction vehicles

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110284
Author(s):  
Weikang Kong ◽  
Jixin Wang ◽  
Dewen Kong ◽  
Yuanying Cong ◽  
Shuangshi Feng
Keyword(s):  
Power Systems ◽  
Control Method ◽  
Simulation Analysis ◽  
Rapid Development ◽  
Transmission Efficiency ◽  
Torque Distribution ◽  
Driving System ◽  
Construction Machinery ◽  
Improve Energy Efficiency ◽  
Parameter Matching

With the rapid development of the world economic construction and the shortage of energy, it has become a hot research issue to realize the electrification of the vehicle driving system and improve energy efficiency. Most of the electric construction machinery power systems are characterized by low speed and high load. The coordinated driving of multiple motors can increase the output torque and improve the transmission efficiency of the machine on the basis of a compact layout. A novel configuration of electric construction vehicles based on multi-motor and single-speed and its driving torque distribution control method is presented in this paper. The detailed mathematical model is established and the simulation analysis is carried out based on it. The results show that the proposed multi-motor driving system with the control strategy can improve the overall efficiency in the condition of ensuring the driving force when the parameter matching and motors choosing reasonably.

scholarly journals Research and Test of Three-Pulley Noncircular Synchronous Pulley Transmission Mechanism with Minimum Slack

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jianneng Chen ◽  
Xincheng Sun ◽  
Chuanyu Wu ◽  
Dadu Xiao ◽  
Jun Ye
Keyword(s):  
Optimization Design ◽  
Simulation Analysis ◽  
Transmission Mechanism ◽  
Driving Mechanism ◽  
Belt Drive ◽  
Drive Mechanism ◽  
Automatic Optimization ◽  
Pitch Curve ◽  
Synchronous Belt Drive ◽  
Belt Transmission

AbstractThe noncircular synchronous belt drive mechanism has demonstrated certain achievements and has been used in special fields. Research regarding noncircular synchronous belt drive mechanisms has focused on optimization design and kinematic analysis in China, whereas two pulley noncircular synchronous belt transmissions have been developed overseas. However, owing to the noncircular characteristics of the belt pulley, the real-time variation in the belt length slack during the transmission of the noncircular synchronous belt is significant, resulting in high probabilities of skipping and vibration. In this study, a noncircular tensioning pulley is added to create a stable three-pulley noncircular synchronous belt driving mechanism and a good synchronous belt tensioning, with no skipping; hence, the non-uniform output characteristic of the driven pulley is consistent with the theoretical value. In the circular noncircular noncircular three-pulley noncircular synchronous belt mechanism, the pitch curve of the driving synchronous belt pulley is circular, whereas those of the driven synchronous belt and tensioning pulleys are noncircular. To minimize the slack of the belt length of the synchronous belt and the constraint of the concavity and circumference of the tensioning pulley, an automatic optimization model of the tensioning pulley pitch curve is established. The motion simulation, analysis, and optimization code for a three-belt-pulley noncircular synchronous belt drive mechanism is written, and the variation in belt length slack under different speed ratios is analyzed based on several examples. The testbed for a circular–noncircular–noncircular three-pulley noncircular synchronous belt transmission mechanism is developed. The test shows that the three-pulley noncircular synchronous belt drives well. This study proposes an automatic optimization algorithm for the tensioning pulley pitch curve of a noncircular synchronous belt transmission mechanism; it yields a stable transmission of the noncircular synchronous belt transmission mechanism as well as non-uniform output characteristics.

Applications of Multiple Objective Genetic Algorithms in the Optimization Design of Tracked Self-Moving Power’s Layout

2013 ◽  
Vol 307 ◽  
pp. 161-165
Author(s):  
Hai Jin ◽  
Jin Fa Xie
Keyword(s):  
Optimization Design ◽  
Pareto Front ◽  
Layout Optimization ◽  
Multiple Objective ◽  
Multi Objective Optimization ◽  
Layout Problem ◽  
Basic Principles ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Set Up

A multi-objective genetic algorithm is applied into the layout optimization of tracked self-moving power. The layout optimization mathematical model was set up. Then introduced the basic principles of NSGA-Ⅱ, which is a Pareto multi-objective optimization algorithm. Finally, NSGA-Ⅱwas presented to solve the layout problem. The algorithm was proved to be effective by some practical examples. The results showed that the algorithm can spread toward the whole Pareto front, and provide many reasonable solutions once for all.

scholarly journals Comparison of materials used for cleaning equipment in retail food premises, and of two methods for the enumeration of bacteria on cleaned equipment and work surfaces

1970 ◽  
Vol 68 (2) ◽  
pp. 221-232 ◽  
Author(s):  
R. J. Gilbert
Keyword(s):  
Control Method ◽  
Field Trials ◽  
Surface Sampling ◽  
Step Procedure ◽  
Cleaning Equipment ◽  
Before And After ◽  
Plate Counts ◽  
Self Service ◽  
Materials Used ◽  
Retail Food

SUMMARYThere is no official scheme for testing disinfectants and detergent/disinfectants for use in the retail food trade and few recommended procedures have been given for the cleaning of equipment with these agents. Therefore, field trials were carried out in a large self-service store. Comparisons were made of the various cleaning efficiencies, as determined by bacterial plate counts, of detergent and disinfectant solutions and machine cleaning oils applied with either clean cloths or disposable paper towels to items of equipment. The most satisfactory results were always obtained when anionic detergent (0·75 % w/v) and hypochlorite (200 p.p.m. available chlorine) solutions were applied in a ‘two-step’ procedure.Tests were made to compare the calcium alginate swab-rinse and the agar sausage (Agaroid) techniques for the enumeration of bacteria on stainless steel, plastic, formica and wooden surfaces before and after a cleaning process. Although recovery rates were always greater by the swab-rinse technique, the agar sausage technique was considered to be a useful routine control method for surface sampling.

Mechanical Property Analysis and Numerical Simulation of Honeycomb Sandwich Structure’s Core

2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You
Keyword(s):  
Numerical Simulation ◽  
Elastic Constants ◽  
Sandwich Structure ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Finite Element Program ◽  
Honeycomb Sandwich ◽  
Calculation Results ◽  
Element Program ◽  
Typical Satellite

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.

The Simulation Analysis of Semi-Active Suspension System in Vehicle Based on Sliding Mode Control with Varying Structure

2011 ◽  
Vol 216 ◽  
pp. 96-100
Author(s):  
Jing Jun Zhang ◽  
Wei Sha Han ◽  
Li Ya Cao ◽  
Rui Zhen Gao
Keyword(s):  
Control Method ◽  
Simulation Analysis ◽  
Reference Model ◽  
Sliding Mode ◽  
Tracking Error ◽  
Active Suspension ◽  
Suspension System ◽  
Sliding Mode Controller ◽  
Error Dynamics ◽  
Dynamic Quality

A sliding mode controller for semi-active suspension system of a quarter car is designed with sliding model varying structure control method. This controller chooses Skyhook as a reference model, and to force the tracking error dynamics between the reference model and the plant in an asymptotically stable sliding mode. An equal near rate is used to improve the dynamic quality of sliding mode motion. Simulation result shows that the stability of performance of the sliding-mode controller can effectively improve the driving smoothness and safety.

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