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.

Synthesis,Structure,and Luminescent and Dielectric Properties of Two Novel 1D Chains Based on a T-Shaped Tripodal Ligand 4-(4,5-Dicarboxy-1H-imidazol-2-yl)pyridine Loxide

Two 1D chain metal-organic framework complexes, {Co[（C10H5N3O5）- （H2O）2？H2O]}n （1） and {Cd[（C10H5N3O5）（H2O）2]}n （2）, based on a T-shaped tripodal ligand 4-（4,5-dicarboxy- 1H-imidazol-2-yl） pyridine 1-oxide （H3DCImPyO） have been reacted under hydrothermal conditions, and were characterized by single-crystal X-ray structure analysis, fluorescent analysis and thermal gravimetric analysis. According to single-crystal X-ray determination, complex 1 crystallizes in the monoclinic system, space group P21/n with a = 9.4930（13）, b = 13.2024（18）, c = 10.5203（14） A^°, β = 98.402（2）°, Z = 4, V = 1304.4（3）A^°3; and complex 2 crystallizes in the monoclinic system, space group C2/c with a = 13.557（3）, b = 13.568（3）, c = 6.7804（13） A^°, β = 105.095（2）°, Z = 4 and V = 1204.2（4） A^°3. Fluorescent analysis of complex 2 showed an intense emission band at 466 nm when the exciting radiation was set at 360 nm. Dielectric constants of complexes 1 and 2 were measured at different frequencies with temperature variation.

Basic Concept and Theoretical Study of Condition-based Maintenance for Power Transmission System

状态检修背景下,为解决电网运行整体与输变电设备个体之间的矛盾和冲突,在已有研究成果基础上,提出电网状态检修的概念,在输变电设备状态检修决策过程中,给出电网故障风险和电网检修风险的定义以及相应的量化表达式。依据设备状态预测,以电网故障风险和电网检修风险的和最小为目标,将设备检修、运行以及电网整体性能在概率引导下相互牵制,形成电网状态检修的数学模型,并给出相应的解决方法。最后,为验证该理论研究的可行性,分别以可靠性测试系统RBTS-BUS6和IEEE-RTS79系统为例,对各种情况进行分析,体现了预期的效果,并期望为电网检修与运行协调决策理论的深入研究提供必要的理论基础。

NEW METHOD TO OBTAIN THE POWER SPECTRA OF HIDDEN VARIABLES AND ITS APPLICATION TO OCEAN DATA

A novel method is proposed to obtain the power spectra of hidden variables in a chaotic time series. By embedding the data in phase space , and recording the conditional probability density of points that the trajectory encounters as it evolves in the reconstructed phase space, it is possible to recover the power spectra of hidden variables in chaotic time series through a spectral analysis over the conditional probability density time series. The method is robust in the application to Lorenz system, 4 dimension Rssler system and rigid body motion by linear feedback system (LFRBM). Applying the method to the time series of sea surface temperature (SST) of the South China Sea, we obtained the power spectra of the wind speed (WS) from SST data. Furthermore, the results showed that there exists an important nonlinear interaction between the SST and the WS.

An optimal strategy for coordinating and dispatching “source-load” in power system based on multiple time scales

Due to the phenomenon of abandoning wind power and photo voltage(PV)power in the“Three Northern Areas”in China,this paper presents an optimal strategy for coordinating and dispatching“source-load”in power system based on multiple time scales.On the basis of the analysis of the uncertainty of wind power and PV power as well as the characteristics of load side resource dispatching,the optimal model of coordinating and dispatching“source-load”in power system based on multiple time scales is established.It can simultaneously and effectively dispatch conventional generators,wind plant,PV power station,pumped-storage power station and load side resources by optimally using three time scales:day-ahead,intra-day and real-time.According to the latest predicted information of wind power,PV power and load,the original generation schedule can be rolled and amended by using the corresponding time scale.The effectiveness of the model can be verified by a real system.The simulation results show that the proposed model can make full use of“source-load”resources to improve the ability to consume wind power and PV power of the grid-connected system.

The Development and Research on the Coordinate Control Strategy Between Turbine and Boiler in Fossil Power Plant

Based on the research on domestic and international automatic technical development in fossil power plant,the paper analyses the recent situation of the coordinate control system between turbine and boiler of domestic fossil Power Plant,provides the development thought of coordinate control system between turbine and boiler,and describes the application prospect in control system of fossil power plant combining with the application experience.

Research on the Influence Factors and Coordinated Control Strategies between Unit and Grid for Isolated Power System

As the existing coordinated control strategies between grid and unit have limitations in isolated power system, this paper introduces new coordinated control strategies which can improve the stability of isolated system operation. This paper analyzes the power grid side and unit side influence factors on the isolated power system. The dynamic models which are suitable for islanding operation are applied to simulate and analyze the stability and dynamic characteristics of the isolated power system under the conditions of different load disturbances and governor parameters. With considering the differences of frequency characteristics between the interconnected and isolated power system, the adjusting and optimization methods of under frequency load shedding are proposed to meet the frequency stability requirements simultaneously in the two cases. Not only proper control strategies of the power plant but the settings of their parameters are suggested to improve the operation stability of the isolated power system. To confirm the correctness and effectiveness of the method mentioned above, the isolated system operation test was conducted under the real power system condition, and the results show that the proposed coordinated control strategies can greatly improve stability of the isolated power system.

Risk Assessment Framework and Algorithm of Power Systems Based on the Partitioned Multi-objective Risk Method

针对平均风险指标无法区分高损失-低概率事件及低损失-高概率事件的缺点,提出了电力系统的分割多目标风险分析框架。该框架将电力系统的风险状态细分为低损失、中等损失和高损失3个风险范围,并提出3个损失范围条件风险函数和条件风险概率的概念。采用经典的容量停运表模型,建立了这些条件期望指标的计算方法。对IEEE-RTS及TH-RTS2000系统进行了分割多目标风险评估,研究不同负荷水平下系统风险在3个损失范围的分布及转移情况,并分析损失分割点对系统风险的影响。通过分割多目标风险分析,风险分析者和决策者可以权衡系统的平均风险以及高、中、低损失范围的条件期望风险,从而对系统的风险状况有一个全面和深入的了解。

Major Powers Cooperate in a Mild and Coordinated Way

Lu:If the tense situations in the Middle East and Northeast Asiabecome relaxed,it would certainly exert great influence on world politi-cal pattern.Can non-traditional security solve the contradictions in thetraditional security field?Will the major powers continue to cooperate inthe anti-terrorist campaign?All these issues will face challenges

Opportunities and Risk Assessment of BRICs New Development Bank——New Big Powers Coordination Perspective

Under the background of counter economic globalization,the Group of Twenty(G20)has become the primary platform for the east and west powers to seek consultation and dialogue.And the coordination mechanism of the new global powers has come into being slowly.As a multilateral regional bank,the BRICsBank takes the interests of developing countries as the leading factor.Based on international economic cooperation ground,it will broaden the South-South cooperation to create more convenient conditions for foreign direct investment,as well as bilateral and multilateral financial cooperation.From new power coordination perspective,with global economy governance structure transformation as the starting point,this research accurately defines the concept of coordination mechanism,systematically analyzes the evolution of global economic governance structure,intensively interprets the current characteristics of big power coordination mode in global economic governance structure,and objective assesses trends of global political and economic pattern.It is of important policy reference implications for the BRICS member countries to effectively promote the BRICs Bank institutionalization and global governance of new power coordination nature.

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.

Consideration of the influence of supports in modeling the electromagnetic fields of 25 kV traction networks under emergency conditions

Single-phase 25 kV traction networks of electrified alternating current(AC)railways create electromagnetic fields(EMFs)with significant levels of intensity.The most intense magnetic fields occur when short circuits exist between the contact wire and rails or ground.Despite the short duration of exposure,they can adversely affect electronic devices and induce significant voltages in adjacent power lines,which is dangerous for operating personnel.Although numerous investigations have focused on modeling the EMF of traction networks and power lines,the challenge of determining the three-dimensional electromagnetic fields near metal supports during the flow of a short-circuit current through them is yet to be resolved.In this case,the field has a complex spatial structure that significantly complicates the calculations of intensities.This study proposes a methodology,algorithms,software,and digital models for determining the EMF in the described emergency scenarios.During the modeling process,the objects being studied were represented by segments of thin wires to analyze the distribution of the electric charge and calculate the intensities of the electric and magnetic fields.This approach was implemented in the Fazonord software,and the modeling results show a substantial increase in EMF levels close to the support,with a noticeable decrease in the levels as the distance from it increases.The procedure implemented in the commercial software Fazonord is universal and can be used to determine electromagnetic fields at any electrical power facility that includes live parts of limited length.Based on the proposed procedure,the EMF near the supports of overhead power lines and traction networks of various designs could be determined,the EMF levels at substations can be calculated,and the influence of metal structures located near traction networks,such as pedestrian crossings at railway stations,can be considered.

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.

利用PowerSATELITE进行广义无功功率测量与分析

介绍了一种新型电能计测终端Power SATELITE(saving assist tool of energy loggering intelligent terminal)。在非正弦波形下利用该仪器进行广义无功功率测量,并与传统功率仪器测量值进行比较,最后总结了两者值差的一般规律。

Landau坐标条件与Mφller坐标条件

Ｌａｎｄａｕ坐标条件保持时空度规号差，但不保持度规矩阵对角项的符号差．坐标条件保持这２种号差。由坐标条件推出了Ｌａｎｄａｕ坐标条件，Ｌａｎｄａｕ坐标条件的主要前提是光沿闭合回路的平均速度是常数ｃ．坐标条件的主要前提是在惯性系中光速为常数ｃ．由于Ｅｉｎｓｔｅｉｎ相对论的前提之一是在惯性系中光速为常数ｃ，所以在Ｅｉｎｓｔｅｉｎ相对论中应用坐标条件是更有效更方便的．在已知的Ｅｉｎｓｔｅｉｎ场方程所有解中，度规矩阵对角项的符号差都为＋２（或－２），其原因就在这里．

MWI in Cylindrical Coordinates and Its Application

Based on FDTD difference expressions and eigenfunctions of Maxwell functions in cylindrical coordinates, mesh wave impedances (MWIs) in 2D and 3D cylindrical coordinates were introduced. Combined with the concept of perfectly matched layer (PML), MWI PML absorbing boundary condition (ABC) algorithm was deduced in 2D cylindrical coordinates. Numerical experiments were done to investigate the validity of MWI and its application in cylindrical coordinates FDTD algorithm. The results showed that MWI in cylindrical coordinates can be used to accurately calculate the numerical reflection error caused by different mesh increments in non uniform FDTD. MWI can also provide theoretical criterion to define the permitted variable range of mesh dimension. MWI PML ABC is easy to be applied and reduces low numerical reflection, which only causes a little higher reflection error compared with Teixeira's PML.

Adaptive coordinated control of engine speed and battery charging voltage

In this paper, the control problem of auxiliary power unit （APU） for hybrid electric vehicles is investigated. An adaptive controller is provided to achieve the coordinated control between the engine speed and the battery charging voltage. The proposed adaptive coordinated control laws for the throttle angle of the engine and the voltage of the power-converter can guarantee not only the asymptotic tracking performance of the engine speed and the regulation of the battery charging voltage, but also the robust stability of the closed loop system under external load changes. Simulation results are given to verify the performance of the proposed adaptive controller.

Review on key technologies and typical applications of multi-station integrated energy systems

To realize the low-carbon development of power systems,digital transformation,and power marketization reform,the substation,data center,energy storage,photovoltaic,and charging stations are important components for the construction of new infrastructure.The integration infrastructure represented by multi-station integrated energy systems(MSIESs)represents the development trend,and its connotation and denotation are not immutable.This study firstly analyzed the components of MSIESs and their sub-stations and overall characteristics,and proposed an overall architecture for MSIESs.Thereafter,this system was characterized in detail from three aspects:planning and design,operation control,and market operation.The planning and construction of MSIESs was analyzed from the aspects of planning and design process,typical fusion subsystems,supply and demand prediction,and capacity determination;the operational control of MSIESs was analyzed from the aspects of model construction,coordination control,and safety assessment.Moreover,the market operation of MSIESs was examined from the aspects of the business model and spot market.Furthermore,the technical development trend of MSIESs has been explored in this study.

High RF power tests of the first 1.3 GHz fundamental power coupler prototypes for the SHINE project

The Shanghai High Repetition Rate XFEL and Extreme Light Facility(SHINE)project will use 6001.3 GHz fundamental power couplers,which are modified based on TTF-Ⅲ power couplers,for continuous-wave operation with input power up to approximately 7 kW.The first batch of 20 sets of 1.3 GHz coupler prototypes was fabricated from three domestic manufacturers for the SHINE project.To better characterize the radio frequency conditioning phenomena for validating the performance of power couplers,a room temperature test stand was designed,constructed,and commissioned for the SHINE 1.3 GHz power couplers.In addition,a horizontal test cryostat was built to test the 1.3 GHz superconducting cavities,fundamental power couplers,tuners,and other components as a set.The results of these tests indicate that the 1.3 GHz couplers are capable of handling up to 14 kW continuous waves.Herein,the main aspects of the radio frequency design and construction of the test stand,along with the test results of the high-power conditioning of the 1.3 GHz couplers,are described.

Massive Power Device Condition Monitoring Data Feature Extraction and Clustering Analysis using MapReduce and Graph Model

Effective storage,processing and analyzing of power device condition monitoring data faces enormous challenges.A framework is proposed that can support both MapReduce and Graph for massive monitoring data analysis at the same time based on Aliyun DTplus platform.First,power device condition monitoring data storage based on MaxCompute table and parallel permutation entropy feature extraction based on MaxCompute MapReduce are designed and implemented on DTplus platform.Then,Graph based k-means algorithm is implemented and used for massive condition monitoring data clustering analysis.Finally,performance tests are performed to compare the execution time between serial program and parallel program.Performance is analyzed from CPU cores consumption,memory utilization and parallel granularity.Experimental results show that the designed framework and parallel algorithms can efficiently process massive power device condition monitoring data.