Design Of Power Transmission System Research Articles

Design Capability Evaluation and System Development for Power Transmission and Transformation Engineering

Power transmission and transformation engineering is a pivotal aspect of power grid construction and an important link to power grid planning. It holds substantial relevance to the economic to the economic, social, and environmental benefits of China’s power construction. Consequently, the design of power transmission and transformation engineering, as the source of power transmission and transformation project construction, holds notable importance. In this paper, the evaluation system of design capability for power transmission and transformation engineering was established from the dimensions of basic hard strength, design bearing capacity, result quality control, deviation control, and technological innovation capacity. The weight of the evaluation indicators of the design capacity of power transmission and transformation engineering is determined based on advanced design units and data analysis combined with expert experience. On this basis, the corresponding evaluation system of design capability was developed. The application of this system provided accurate basic data for the evaluation of design capabilities in power transmission and transformation engineering. The design capability assessment report issued can help provincial companies comprehensively evaluate the design capabilities of various design units, thereby promoting standardized management of design units.

The Efficiency Improvement of Track-Type Wireless Power Transmission Systems through Electromagnetic Finite Element Analysis

The original system, designed as a combination structure of a linear machine and a wireless power transmission transformer, was designed to overcome the limitations of the wired power supply method used for working robots and transportation equipment in existing smart factories, and improvements in magnetic coupling and power transfer efficiency are needed. In this work, we study the efficiency improvement of a system that can supply wireless power to track-type transportation equipment. For this purpose, electromagnetic properties such as magnetic equivalent resistance, inductance, magnetic coupling rate, and core loss are analyzed using the finite element method. In addition, the results of magnetic field finite element analysis are applied in electrical equivalent circuit modeling to analyze the voltage transfer ratio and input/output characteristics of a CLLC resonant converter designed for wireless power transmission. The efficiency improvements of the proposed model are verified through a comparison of experimental and simulation results after fabricating a prototype. From the results of this study, a more optimized wireless power transmission system design based on the analysis results from an electromagnetic perspective can be realized to improve the efficiency of wireless power transmission.

Application of Triple Active Bridge Converter for Future Grid and Integrated Energy System

Abstract: Renewable energy systems and electric vehicles (EVs) are receiving much attention in industrial and scholarly communities owing to their roles in reducing pollutant emissions. Integrated energy systems (IES), which connect different types of renewable energies and storages, have become common in many applications, such as the grid-connected photovoltaic (PV) and battery systems, fuel cells and battery/super capacitor in EVs. The advantages of all energy sources are maximized by utilizing connection and control strategies. Because many storage systems and household loads are mainly direct current (DC) types, the DC grid has considerable potential for increasing the efficiency of distribution grids in the future. In IES and future DC grid systems, the triple active bridge (TAB) converter is an isolated bidirectional DC-DC converter that has many advantages as a core circuit. In this paper reviews the characteristics of the TAB converter in current applications and suggests nextgeneration applications. First, the characteristics and operation modes of the TAB converter are introduced. An overview of all current applications of the TAB converter is then presented. The advantages and challenges of the TAB converter in each application are discussed. Thereafter, the potential future applications of the TAB converter with an adaptable power transmission design are presented.

Design and Optimization of Working Parts of Vertical Spiral Ditching Machine Based on Milling Force and BP Neural Network Model

The existing vertical spiral ditching machine mainly works in flat orchards, and the structural design of ditching components does not match the design of power transmission system, which leads to high ditching power consumption and poor ditching stability. According to the needs of deep application of organic fertilizer in orchards, a spiral cutter was designed to alleviate the common problems of high power consumption and poor stability of ditching machine and reduce the power consumption of ditch cutting. Therefore, the motion parameters and structural parameters of the spiral cutter are optimized. Using ANSYS preprocessor, the finite element model of cutting soil with spiral cutter is established, and the implicit functional relationship between milling force factor and instantaneous cutting thickness is established by using BPNN (BP neural network). On the basis of the established prediction model of milling force, orthogonal experiments were carried out to obtain the best combination of cutter head rotation speed, slotting depth, and advancing speed with minimum power consumption: 20.16 rad/s, 0.3 m, and 0.12 m/s. By investigating the influence of various working parameters on the power consumption of ditching machine, the analysis basis is provided for selecting reasonable working parameters of ditching machine.

ВИКОРИСТАННЯ ПРОГРАМНОГО ЗАБЕЗПЕЧЕННЯ ДЛЯ ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ МОДЕЛЮВАННЯ ЕНЕРГЕТИЧНИХ МЕРЕЖ

The article is devoted to the topical issue of power grid modeling. The article discusses positive and negative features of simulation programs. Particular attention is paid to the principles of the programs. Such programs as PSS®SINCAL from Siemens; ETAP from Operation Technology and PowerFactory from DIgSILENT GmbH are considered in the article. The PSS®SINCAL software specializes in designing networks from low to ultra-high voltage classes, in symmetrical and non-symmetrical modes of operation, takes into account the installation possibilities of compensating devices and gives recommendations for their installation locations. Basic models enabling mode calculations and shortcircuit calculations as well as simulation of electromagnetic transients are used as the basis of the PSS®SINCAL software. The basic modules include steady state calculations, calculations of short circuit currents, harmonics, system stability and electromagnetic transients. Particular attention is paid to the optimization and planning module, namely reactive power optimization. The module of reactive power optimization in PSS®SINCAL offers methods of optimizing existing equipment by finding the best switching points for reactive power compensation. ETAP software specializes in electrical network and power transmission design. ETAP Grid™ connects network design with detailed substation models, SCADA systems, and real-time transmission network management. This paper covers only 2 modules of ETAP software, namely transmission and distribution modules. PowerFactory captures the full range of functionality from standard features to highly sophisticated and advanced applications, including wind power, distributed generation, real-time modeling, and performance monitoring for testing of surveillance systems. This article reviews only 2 modules of the PowerFactory software, namely the electrical power transmission and distribution modules. The paper reviews the programs and concludes that Siemens' PSS®SINCAL software would be the most successful solution for modeling electric grids and accounting for the effects of compensating devices on voltage levels in electric grids.

Performance based systematic design methodology for development and flight testing of fuel engine powered quadrotor Unmanned Aerial System for industrial applications

This paper presents a systematic study of the design optimization, development, vibration analysis and flight testing of a single power plant variable pitch quadrotor Unmanned Aerial System (UAS) for industrial applications. The use of variable pitch rotors enables the use of a two-stroke internal combustion engine for powering the four rotors through a mechanical transmission. The proposed methodology is described by carrying out the design of a quadrotor UAS with 2–3 kg payload capacity and have endurance in excess of one hour. The study is conducted in a systematic manner. First, the design of rotors is optimized for minimum power consumption during hover as well as forward flight condition using physics based simulation developed and validated for this purpose. From the rotor optimization, an untwisted rotor blade with taper ratio of 0.6 and aspect ratio of 10 appeared to be an optimal choice for the current design. Next, the powerplant selection is carried out based on the optimized rotor designed earlier. Next, two different approaches for mechanical power transmission design is considered: torque tube-bevel gear and belt–pulley system based designs. The transmission system designed using belt and pulley was nearly 14% lighter and showed greater tolerance to manufacturing imperfections. Next, two prototypes are designed and its static and dynamic analysis is carried out to ensure its airworthiness. A Proportional Integral Derivative (PID) based attitude controller is developed using quarternions for attitude stabilization and trajectory tracking to test the flight in simulation and then subsequently on the actual vehicle by implementing it on PixHawk autopilot board. Finally, system integration is carried out to build two prototypes of engine powered quadrotor UAS. Then, vibration data is recorded using the sensors onboard to conduct the vibration analysis and design an efficient vibration isolator. Performance analysis is also, carried out to estimate the speed for best endurance (11 m/s) and best range (27 m/s) for the variable pitch quadrotor designed. The estimated best endurance achieved is 2.2 h and estimated best range is more than 150 km. This design revisits and solves the challenge of developing an agile helicopter without cyclic pitch control which was first explored nearly a century ago.

Three-Dimensional Geographic Information System Assisted Intelligent Review of Power Grid Design

In order to strengthen the management of the three-dimensional design review of power transmission and transformation projects, the Ministry of Infrastructure of the State Grid has successively issued the “Notice of Guiding Opinions on the Management of Preliminary Evaluation of Three-Dimensional Design of Transmission and Transformation Projects” and the “Preliminary Review Outline of Three-dimensional Design of Transmission and Transformation Projects (for Trial Implementation) )announcement of”. At present, most of the existing engineering design review systems are two-dimensional systems, which cannot visually display design results. In order to better display the results of three-dimensional design and improve review efficiency, it is necessary to apply GIS technology to the three-dimensional design of power transmission and transformation projects, and it is very necessary to develop a set of 3D GIS power transmission and transformation engineering design review system. In order to solve the above problems, the purpose of the present invention is to provide a method based on 3D GIS power transmission and transformation engineering design review, using 3D visualization technology to combine GIS with power transmission and transformation engineering design results to achieve visual browsing and query of 3D design models, and 3D design Achievement display,3D design results review and scoring,3D design model collision relationship calculation and other intelligent management applications.

Intelligent computing of positive switching impulse breakdown voltage of rod-plane air gap based on extremely randomized trees algorithm

The insulating strength of an air gap is an important basis for external insulation design of power transmission and transformation project, and both gap structure and meteorological conditions have a great influence on the breakdown voltage of air gap. The temperature, humidity and other meteorological conditions in the actual operating environment of power transmission and transformation projects may change greatly with time, so presently, there is no better method to calculate the breakdown voltage of air gaps in various meteorological conditions. In this paper, a prediction model for positive switching impulse breakdown voltage of rod-plane air gap based on extremely randomized trees is proposed. All samples are divided into training set and test set by Self-Organizing Mapping neural network and stratified sampling method. In the test set, the predicted breakdown voltage results of rod-plane air gap based on decision trees, random forest, extremely randomized trees and support vector machine are compared, with reference to the rectification results of atmospheric correction method. The result shows that the maximum absolute relative error of the model is 4.3% and the mean absolute percentage error is 1.6%. Then, the importance of features of import variables is calculated with the trained extremely randomized trees model. Finally, the breakdown voltage of rod-plane air gap in correspondence to different gap distances in four extreme meteorological conditions is calculated with the model. The method can provide reference for calculation of the breakdown voltage of air gap in various meteorological conditions.

Results of experimental studies of an agricultural tractor with an elastic-damping mechanism in a power train

Improving the operational efficiency of agricultural tractors is one of the main factors that helps to increase productivity while significantly reducing energy costs. The developments that are associated with improving the design of power transmissions for wheeled agricultural tractors are very important, because its indispensable condition is to increase labor productivity in agricultural production. Achievement of the required characteristics of agricultural tractors is determined by the properties of the power train and the interaction of associated systems. One of the main qualities of a power train should be the ability to absorb torsional vibrations and damp the load.
 The article presents studies of the constructive improvement of the power transmission of an agricultural tractor by installing a developed elastic-damping mechanism using the example of a tractor of a small traction class. Considering the relevance of the topic, the article solved the problem of determining the influence of the elastic-damping mechanism installed in the power transmission of the tractor on its operation with the cultivator.
 The paper analyzed the cross-correlation function and the mutual spectral density of two processes: the angular speed of rotation of the crankshaft of the engine and the angular speed of rotation of the drive wheel, which showed a change in the speed of propagation of passing frequencies of load oscillations along the shafting and displacement of the frequency of disturbing influences.

Innovative Meshing Strategies for Bearing Lubrication Simulations

Efficiency improvement is the new challenge in all fields of design. In this scenario the reduction of power losses is becoming more and more a main concern also in the design of power transmissions. Appropriate models to predict power losses are therefore required from the earliest stages of the design phase. The aim of this project is to carry out lubrication simulations of several variants of a cylindrical roller bearing to understand the lubricant distribution and the related churning power losses. Several strategies to reduce the computational effort were used. Among them the sectorial symmetry and three innovative meshing strategies (purely analytical with and without interfaces and analytical/subtractive) that were implemented in the OpenFOAM® environment. The results of the different approaches were compared among them and reasonable savings in terms of computational effort were shown.

Applications of Triple Active Bridge Converter for Future Grid and Integrated Energy Systems

Renewable energy systems and electric vehicles (EVs) are receiving much attention in industrial and scholarly communities owing to their roles in reducing pollutant emissions. Integrated energy systems (IES), which connect different types of renewable energies and storages, have become common in many applications, such as the grid-connected photovoltaic (PV) and battery systems, fuel cells and battery/supercapacitor in EVs. The advantages of all energy sources are maximized by utilizing connection and control strategies. Because many storage systems and household loads are mainly direct current (DC) types, the DC grid has considerable potential for increasing the efficiency of distribution grids in the future. In IES and future DC grid systems, the triple active bridge (TAB) converter is an isolated bidirectional DC-DC converter that has many advantages as a core circuit. Therefore, this paper reviews the characteristics of the TAB converter in current applications and suggests next-generation applications. First, the characteristics and operation modes of the TAB converter are introduced. An overview of all current applications of the TAB converter is then presented. The advantages and challenges of the TAB converter in each application are discussed. Thereafter, the potential future applications of the TAB converter with an adaptable power transmission design are presented.

Retrodirective Antenna 기반 무선전력전송을 위한 전력 송수신기 설계 및 특성 평가

This paper presents a retrodirective antenna(RDA)-based wireless power transmission system design method using link budget analysis. The simulation and measurement results demonstrate the feasibility of this method. The system can transmit a power signal by adaptive beamforming toward the power receiver. The system should be designed considering various factors from the pilot signal generation to the rectified power signal reception. Through this design method, the system can achieve the target distance and efficiency required for wireless power transmission. This study confirms the characteristics of the radio frequency-to-direct current rectifier used in the link budget analysis through a simulation. The measurement results indicate that the total antenna gain required can be effectively achieved by the design method using multiple antenna modules. In other words, the link budget analysis can be used to effectively design an RDA-based wireless power transmission system.

Three Dimensional Information Sharing Platform of Power Transmission and Transformation Based on Grid Information Model (GIM)

Grid information model (GIM) is a technical standard formulated by State Grid Corporation of China to meet the needs of three-dimensional design of power transmission and transformation projects [1]. According to the characteristics of GIM data, this paper studies the design of distributed computing technology and service architecture to realize the online analysis and optimization of GIM data, so as to improve the efficiency and performance of GIM data analysis. Based on WEBGL technology, with the help of 3D tiles’ LOD ability and the openness of format, a 3D information sharing platform for power transmission and transformation is built to realize the efficient and smooth loading, display and sharing of GIM 3D data on the web.

A parameter matching study for power system of electric sweeping vehicle based on AVL CRUISE

Electric sweeper is the hot spot of research and development at present, and parameter matching design of power transmission system is a key technology. The practical significance of developing electric sweeper is introduced, the parameters of power system are designed based on the energy transfer of the whole vehicle, parameters of the motor and power battery are designed and selected to meet the performance design target, and the final drive and the second gear ratio are determined. The whole vehicle model is established and dynamic analysis is carried out using AVL CRUISE software. The simulation results show that the parameters designed for the power system meet the design requirements. It provides a reference for the design and research of power system of electric sweeper.

Analysis of the tooth root roughness of hobbed gears

For the design of power transmissions, an increase in power density is necessary. This leads to higher requirements for the tooth root design of the respective gears with high load capacity. The permissible tooth root stress of gears is influenced by the roughness at the tooth root. The influence of different process and tool designs on the roughness at the tooth root was determined for hobbing. To predict the roughness at the tooth root, a model was developed with which the roughness at the tooth root can be calculated. The model can be used as a helpful tool for gear design.

Assistive devices of human knee joint: A review

Knee dysfunction, such as knee osteoarthritis, meniscus injury, ligament injury, spinal cord injury and stroke, considerably impacts the normal living ability and mental health of these patients. Developing more effective knee assistive devices is in urgent need for effectively recovering their motion capabilities and improving their self-living activities. In this paper, we review and discuss the mechanical system design, sensing and control systems design, and performance evaluation of the main research advances in knee assistive devices. Firstly, in order to clearly illustrate and compare the mechanical system design, the mechanical system design is classified into four components to discuss: human attachment design, joint alignment design, actuation design and power transmission design. Then, the sensing and control systems design, which includes human biological signals based control systems, human–device interaction signals based control systems and device signals only based control systems, is compared and discussed. Furthermore, the performance evaluation methods and effectiveness of most of the knee assistive devices are reviewed. Finally, a discussion of the existing problems in the current studies and some recommendations for future research are presented.

Genetic Approach for Multiobjective Optimization of Epicyclical Gear Train

The determination of optimal design of the planetary gear train with a lightweight, a short center distance, and a high efficiency is an important issue in the preliminary design of power transmission systems. Conventional and traditional methods have been widely used in optimization. They are deterministic and limited to solve some mechanical problems with several variables and constraints. Therefore, some optimization methods have been developed, such as the nonconventional method, the genetic algorithm (GA). This paper describes a multiobjective optimization for the epicyclical gear train system using the GA. It is aimed to obtain the optimal dimensions for epicyclical gear components like a module, number of teeth, the tooth width, the shaft diameter of the gears, and a performed efficiency under the variation of operating mode of PGT system. The problem is formulated under the satisfaction of assembly and balance constraints, bending strength, contact strength of teeth, and other dimension conditions. The mathematical model and all steps of the GA are presented in detail.

Application of UAV arial survey in Three-Dimensional Design of Transmission Lines

The three-dimensional design of power transmission and transformation engineering is the mainstream trend of current power engineering design work. Based on the three-dimensional image model for power engineering design, path optimization and electrical distance calibration can be carried out more intuitively and conveniently. In this paper, the multi-rotor uav is equipped with sensors to collect image data, and establish a real-time model of the transmission line corridor to provide data support for the three-dimensional design of the transmission project. At the same time, the three-dimensional model is compared with the artificial measured results, and the applicable scope of the uav real-world modeling is summarized.

Novel Design of 2.45-GHz Rectenna Element and Array for Wireless Power Transmission

A novel design of 2.45-GHz rectifying antenna (rectenna), which is composed of antenna element, two-element series-fed array, and four-element cascaded array, has been proposed in this paper. The array designs are introduced in order to adapt various power density is used in the array, especially in near-field of the transmitting antenna, in this case, the power density in the center and far away from center differs greatly. The compact low-profile air supported microstrip antenna is introduced as receiving antenna element in order to reduce substrate loss. The rectifying circuit has been designed and optimized using ADS software. The diode in the rectifying circuit is installed in series and the capacitance is replaced by microstrip line as dc pass filter. A maximum RF to dc conversion efficiency of the rectifying circuit can reach 80% when the input power is 21 dBm and 3500-Ω resistive load is connected to the circuit end through experiment. The rectenna exhibits a maximum efficiency of 77.2% and an output dc voltage of 18.5 V. The proposed rectenna element and the array can be easily expanded to a large scale integrated rectenna arrays, it will be practically attractive for wireless power transmission system design.

Model for the calculation of kinematic roughness in the tooth root

For the design of power transmissions, an increase in power density is necessary. This development leads to higher requirements on the tooth root design with high load capacity. In addition to optimizing the load and stress distribution by adapting the tooth root geometry, the load capacity of the gears can be increased by optimizing the workpiece surfaces. For this reason, a model for predicting the geometric deviations due to kinematics in the tooth root and their influence on the roughness is to be developed. With this model, the ideal roughness resulting from the process kinematics of hobbing can be predicted and used for process design.