Design and high-power testing of offline conditioning cavity for CiADS RFQ high-power coupler

To validate the design rationality of the power coupler for the RFQ cavity and minimize cavity contamination,we designed a low-loss offline conditioning cavity and conducted high-power testing.This offline cavity features two coupling ports and two tuners,operating at a frequency of 162.5 MHz with a tuning range of 3.2 MHz.Adjusting the installation angle of the coupling ring and the insertion depth of the tuner helps minimize cavity losses.We performed electromagnetic structural and multiphysics simulations,revealing a minimal theoretical power loss of 4.3%.However,when the cavity frequency varied by110 kHz,theoretical power losses increased to10%,necessitating constant tuner adjustments during conditioning.Multiphysics simulations indicated that increased cavity temperature did not affect frequency variation.Upon completion of the offline high-power conditioning platform,we measured the transmission performance,revealing a power loss of 6.3%,exceeding the theoretical calculation.Conditioning utilized efficient automatic range scanning and standing wave resonant methods.To fully condition the power coupler,a 15°phase difference between two standing wave points in the condition-ing system was necessary.Notably,the maximum continuous wave power surpassed 20 kW,exceeding the expected target.

Review of Thermal Design of SiC Power Module for Motor Drive in Electrical Vehicle Application

In the current vehicle electric propulsion systems,the thermal design of power modules heavily relies on empirical knowledge,making it challenging to effectively optimize irregularly arranged Pinfin structures,thereby limiting their performance.This paper aims to review the underlying mechanisms of how irregularly arranged Pinfins influence the thermal characteristics of power modules and introduce collaborative thermal design with DC bus capacitor and motor.Literature considers chip size,placement,coolant flow direction with the goal of reducing thermal resistance of power modules,minimizing chip junction temperature differentials,and optimizing Pinfin layouts.In the first step,algorithms should efficiently generating numerous unique irregular Pinfin layouts to enhance optimization quality.The second step is to efficiently evaluate Pinfin layouts.Simulation accuracy and speed should be ensured to improve computational efficiency.Finally,to improve overall heat dissipation effectiveness,papers establish models for capacitors,motors,to aid collaborative Pinfin optimization.These research outcomes will provide essential support for future developments in high power density motor drive for vehicles.

Research on typical operating conditions of hydrogen production system with off-grid wind power considering the characteristics of proton exchange membrane electrolysis cell

Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs.

Probabilistic Global Maximum Power Point Tracking Algorithm for Continuously Varying Partial Shading Conditions on Autonomous PV Systems

A photovoltaic (PV) string with multiple modules with bypass diodes frequently deployed on a variety of autonomous PV systems may present multiple power peaks under uneven shading. For optimal solar harvesting, there is a need for a control schema to force the PV string to operate at global maximum power point (GMPP). While a lot of tracking methods have been proposed in the literature, they are usually complex and do not fully take advantage of the available characteristics of the PV array. This work highlights how the voltage at operating point and the forward voltage of the bypass diode are considered to design a global maximum power point tracking (GMPPT) algorithm with a very limited global search phase called Fast GMPPT. This algorithm successfully tracks GMPP between 94% and 98% of the time under a theoretical evaluation. It is then compared against Perturb and Observe, Deterministic Particle Swarm Optimization, and Grey Wolf Optimization under a sequence of irradiance steps as well as a power-over-voltage characteristics profile that mimics the electrical characteristics of a PV string under varying partial shading conditions. Overall, the simulation with the sequence of irradiance steps shows that while Fast GMPPT does not have the best convergence time, it has an excellent convergence rate as well as causes the least amount of power loss during the global search phase. Experimental test under varying partial shading conditions shows that while the GMPPT proposal is simple and lightweight, it is very performant under a wide range of dynamically varying partial shading conditions and boasts the best energy efficiency (94.74%) out of the 4 tested algorithms.

Wall Conditioning Operation on the HL-2A Tokamak and Conceptual Design for the Device Modification

During the 2006 experiment campaign of HL-2A, about 2000 shots have been implemented, the plasma current of 433 kA and 3.0 s duration have been obtained. The wall conditioning methods such as glow discharge cleating （GDC） , siliconization and Ti sublimation were applied. The experiment results of wall conditioning research will be introduced in this report. At the same time, the conceptual design of modification of HL-2A tokamak has obtained great progress, two modification schemes have been obtained, and the conceptual design results will be presented.

Visual Interactive Computer Package for Air Conditioning System Design: Case of the International Conference Centre, University of Ibadan, Nigeria

Air conditioning design has become an interesting aspect of human life with the aim of seeking environmental comfort for indoor spaces. Analytical work involves in the design of air-conditioning system is often time consuming and laborious. This work therefore aims at developing a visual interactive computer package for the design of air conditioning system using the international conference centre, University of Ibadan, Nigeria as a case study. Procedures for calculating heat gain through various building components were discussed in detail. Cooling load analysis was carried out using standard cooling load equations obtained from the American Society of Heating, Refrigeration and Air conditioning Engineers (ASHRAE) handbook. A computer program was developed using java programming language to compute the total cooling load in the building. The result from the computer program was obtained within a very short period of time when compared with that of the manual one. The cooling load of the building obtained was 3,194,414 btu/hr;a visual interactive computer package for the design of air conditioning system has been developed and tested positively;hence can be used to design air conditioning system for any building.

Selection of Weather Parameters for Air-Conditioning System Design for Buildings with Long Thermal Lag

Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling load.So the two factors should be taken into account when selecting the weather parameters for air-conditioning system design.This paper developed a new statistic method for the rational selection of coincident solar irradiance,dry-bulb and wet-bulb temperatures.The method was applied to historic weather records of 25 years in Hong Kong to generate coincident design weather data.And the results show that traditional design solar irradiance,dry-bulb and wet-bulb temperatures may be significantly overestimated in many conditions,and the design weather data for the three different constructions is not kept constant.

Load Management Scheme Using Air Conditioning Electric Power Consumption and Photovoltaic Power System Generation

In the last few decades, in the world and also in the European Union, considerable resources had been invested in the rapid development of renewable energy sources and distributed generation in general. At the same time, power consumption is continuously increasing, and consumers are becoming more complex, which ultimately requires new investments in the distribution network. Concept of smart grids is generally accepted as a possible solution. Smart grid is a concept with many elements, where monitoring and control of every element in the chain of production, transmission, distribution and final consumption enable much more efficient delivery and use of electricity. One of the elements of smart grid efficiency is the ability of real-time demand-supply balancing. This balancing is carried out by monitoring of consumption and redistribution of electricity among individual end users, according to their needs. The aim of this paper is creating algorithm for real-time load management using power measurements. Algorithm for real-time load management at the ETFOS （Faculty of Electrical Engineering in Osijek）, Croatia is created based on measurements of photovoltaic power plant production, the power consumption of air conditioning system and the faculty building total electricity consumption. Expected result of real-time re-dispatching of air conditioners consumption, depending on the level of electricity production in photovoltaic power plant is decreasing peak demand of the faculty.

Application of Fuzzy Comprehensive Evaluation to Air-conditioning Competitive Power Analysis

As the conceptual design of air-conditioning is done using the theory of Quality Function Deployment (QFD),cus- tomer requirements should be understood and the product competitive power be analyzed as exactly as possible for new product de- signing.Lots of information in the process of this research is fuzzy and uncertain,but traditional QFD can not deal with it well. Fuzzy theory can solve the problem.So a fuzzy model for analyzing product competitive power is formulated in this paper to im- prove traditional QFD,after that it is applied to analyze air-conditioning competitive power.When air-conditioning competitive power is analyzed using this model,firstly the importance weight of the customer requirements o fair-conditioning is determined us- ing the Analytic Hierarchy Process (AHP) weighting process,then air-conditloning competitive power is evaluated using fuzzy comprehensive evaluation.It is proved that the model is feasible and has good applicability.

基于PowerDesigner的信息系统数据模型建设

介绍了信息系统的开发过程,说明了PowerDesigner的功能和建立数据模型的流程.最后举 例说明如何利用PowerDesigner中的CDM、PDM建立概念模型、逻辑模型和物理模型.

利用Power Designer设计REA模型

REA模型是一种基于企业价值链分析、以事件为驱动的会计信息系统的数据模型,其内涵是"资源—事件—参与者"会计模型。数据库设计工具Power Designer的CDM可以实现REA模型从概念模型到关系模型的转化,进而产生数据库表,方便用户查询使用。

基于Power Designer的数据库系统构建

Power Designer是一个运行在Windows平台上的系统建模工具,它可以使软件开发人员和数据库管理员协同工作,快速建立起软件的系统模型,为开发一个稳定可靠的软件打下基础。文中通过实例的建设过程,介绍了Power Designer的分析设计过程及软件代码、数据库的生成过程。

基于UML/Power Designer的信息系统分析方法

本文主要针对基于UML/PowerDesigner的信息系统分析方法进行研究:在基于面向对象UML的平台上,以CRM客户关系管理信息系统为研究对象,对其需求模型,总体设计模型和详细设计模型进行了分析设计,并采用了基于UML建模语言的CASE工具PowerDesigner进行进一步的辅助分析和设计,得到了CRM的相关实现模型。本文的研究对管理信息系统的分析方法提供了一种实用的技术途径。

基于PowerDesigner的家庭财务管理系统的数据库设计

该文介绍了基于Power Designer的家庭财务管理系统数据库建模的过程。通过对系统的需求和功能以及数据流程进行分析,设计系统所需数据项和数据结构。在数据库分析的基础上设计系统的实体和关系并使用Power Designer工具建立概念数据模型,逻辑数据模型。根据关系模式以及转换规则得到数据库模式。

Power Designer在数据仓库系统开发过程中的应用研究

本文介绍了数据仓库系统的开发过程,对Power Designer在数据仓库系统开发过程中的应用进行了研究。

数据库设计工具的选择——Erwin,Power Designer,Rational Rose

随着数据库设计的需要,越来越多的CASE工具出现在我们的视野里,如何选择适合自己的工具就成了当务之急,下面对几种常用的工具Erwin,Power Designer,Rational Rose做以下对比。

基于PowerDesigner的公路工程地理信息平台数据库建模

利用CASE工具PowerDesigner,设计了公路工程地理信息平台数据库模型。本文首先简述了PowerDesigner的建模方法与步骤,在分析平台系统总体结构的基础上,探讨了公路工程数据的组织,以及利用PowerDesigner建立概念数据模型和物理数据模型等建模的关键问题,通过广东省公路工程地理信息平台数据库建模实践,验证了文中的建模方法。

基于PowerDesigner的数据模型研究

随着数据库技术的迅速发展，它已经成为计算机信息系统和应用系统的基础和核心。而数据库系统的核心是建立在数据模型基础上的，本文主要介绍了数据模型的组成要素和基于PowerDesigner的数据建模流程及正、逆向工程。

Power Designer在数据库设计中的应用

介绍了Power Designer工具的数据库建模流程。以网上商品销售系统的数据库设计为例,论述了Power Designera在数据库设计中的具体应用,从而使学生区分理论中各设计阶段的任务和关系,提高了数据库设计动手与实践能力。

基于Power Designer的三维工程地质数据仓库模型构建——以长春市中心区为例

论文以长春市地下空间的岩土体可利用性为研究主题,以勘察工程中提供的钻孔数据及其相关信息为源数据,采用Power Designer16.1设计并实现了长春市中心区的三维工程地质数据仓库的逻辑数据模型和物理数据模型。采用模型驱动架构的方式,利用反向工程技术从Access数据库系统中将现存的数据结构抽取出来形成数据模型,结合研究主题建立了星型数据结构模型,并将生成的SQL脚本文件导入SQL Server2005中进行检查修正后运行正常。