变压器零序差动保护原理及调试

变压器差动保护用于防御变压器绕组和引出线多相短路、大电流接地系统侧绕组和引出线的单相接地等故障,与瓦斯保护共同构成了变压器的主保护。而保护装置针对自耦变压器,还配置了零序差动保护。结合自耦变压器的结构特点。以南自PST1200变压器保护装置为例分析了零序差动的原理构成及特点．简要总结了零差保护的调试方法,能够较快且准确的校验零差保护逻辑功能的正确性,并已在实际工作中得到了很好的验证。     

变压器差动保护制动曲线测试新方法

正常情况下使用三相电流的继电保护测试仪测试变压器差动保护制动曲线时,一般采取分相测试,即需在非测试相串联接入补偿电流或采用调整补偿系数的方式抑制非测试相动作。据此提出了一种新的测试方法,根据实际情况让变压器保护装置单相、两相或三相同时动作或不动作,并对几种典型变压器差动保护的接线方式进行了分析测试。结果表明,新方法合理、有效,测试数据与传统测试方法完全吻合。     

箱式柴油机电站分布式控制系统

本文阐述了一种将多台箱式柴油机电站设备进行组网的方法。系统硬件主要由S7-200 PLC、HGM6510并机控制器、巡检仪、AGB发电机后备保护装置、ASB变压器后备保护装置、ASL线路保护测控装置和AST变压器差动保护装置组成。通过将所有设备组网,实现对箱式柴油机电站各种设备运行数据采集和状态监控,及远程紧急停机、合/分闸、功率设置等功能,实现了大型箱式电站的集中监视与控制。     

空投变压器差动保护动作分析

分析了2007年4月29日科技园变空投变压器时,主变差动保护误动作过程。得出主变差动保护误动作主要是空投变压器产生的二次谐波占基波比例小于定值中的制动系数（0．17）,导致A、B相闭锁条件开放,差动出口跳闸。根据误动原因提出应采用波形对称原理的保护装置。     

核电厂变压器零序差动保护配置及其整定计算

百万核电机组的主变压器通常由3台500 kV单相变压器构成,单相接地故障是其主要故障型式之一,零序电流差动保护是针对单相接地故障的主保护。目前可供选用的零序电流差动保护装置的保护原理主要是比例制动式差动保护,在技术细节上仍存差异,保护整定计算方法不同,对电流互感器的配置适应性也不同。针对两类不同的零序电流差动保护原理,并分析其适应的不同情况,提出核电厂主变压器零序电流差动保护设计方案及其保护整定计算方法。     

浅析某厂1#主变压器差动保护的差流控制

本文针对青溪电厂1#主变压器差动保护在带负荷测试过程中出现的差流过大问题,结合变压器差动保护的原理及带负荷测试,分析了差流过大的原因,并提出了处理方法.     

基于实时数字仿真器的变压器保护装置研究

变压器保护装置作为电力变压器的主保护和后备保护,在电力系统中已得到广泛应用,但目前变压器保护装置在接入电网前经过了继电保护测试仪的简单测试,缺乏接入模拟电网的调试,因此无法确保设备性能满足实际要求。研究利用实时数字仿真器(RTDS)准确模拟电力系统发生故障的过程,建立模拟电网,针对变压器保护装置的测试,对变压器保护装置的原理进行了分析,在RTDS平台上设计了供电系统模拟系统和对应控制回路,在模拟电网系统中通过设置各种异常工况模拟常见电网故障情况。     

差动保护在高压变频器中的应用

以工程实例,介绍了在大容量电机加装了高压变频器后如何实现差动保护的正常应用.通过差动保护原理,变频电流互感器的应用和微机差动保护装置原理等方面上逐一论证了差动保护在变频系统中应用的可行性,并结合新昌电厂的案例提出了具体的工程解决方案.     

提高微机型变压器保护可靠性的探讨

对微机变压器保护进行了评述,以在电力系统应用并得到推广的CSC-326数字式变压器保护装置的特点及功能为例,探讨了提高变压器保护可靠性的措施,从变压器保护原理角度分析了影响变压器保护可靠性的因素.现场运行证明,该措施有效,满足变压器保护的可靠性、选择性、速动性、灵活性要求.     

Yn/Y接线变压器单相接地短路差动保护动作分析

分析了Yn/Y变压器微机差动保护在保护区外发生单相接地短路故障时,由于零序电流的存在将使变压器差动保护可能出现误动.用不对称理论对单相接地短路故障备序电流进行分析,得出变压器差动保护区外误动原因并提出防误动的措施.验证了变压器差动保护区内单相接地短路故障时单侧电源与双侧电源的变压器差动保护的灵敏度.     

论新型减温减压装置中减温系统的优越性

减温减压装置是用来将新蒸汽压力、温度降低到用户所需要的蒸汽参数的一种专用装置。旧型减温减压装置采用的是给水分配阀、节流装置、喷嘴等组合结构形式的减温系统 ,存在着许多的弊端和不足之处。经分析研究 ,重新设计开发了一种新型喷水调节阀式减温系统 ,完全取代了旧型系统 ,具有高可调比、低泄漏量、管路简单、可调压差范围大等优点。通过对旧型与新型减温系统工作原理及特点的比较 ,阐述了新型减温系统的优越性。     

Smart switchable glazing for solar energy and daylight control

The exciting field of chromogenic materials for smart windows and other large-area applications is discussed. A selection of switchable glazing devices that change color electrically are detailed. The types of devices covered are the electrochromic which change color electrically, covering electrochromic, dispersed liquid crystal and dispersed particle glazing that switch under an applied electric field. Device structures and switching characteristics are compared. The status of prototype and commercial devices from commercial and university labs through out the world are covered. A discussion of the future of this technology is made including areas of necessary development for the realization of large area glazing in excess of 1m².     

新型线路保护装置在练塘变电站的应用

500kV练塘变电站是上海第一座数字化变电站,电压等级高、数字化设备新而且规模大。介绍了一种新型线路保护装置PRS-753,采用相关差动法的工作原理,在上海电网的应用情况。通过对保护装置功能的分析,指出了其在差动保护功能、通道投退和自动化通信接口方面的特殊性和不同之处,提出了保护装置的一些硬件功能,由于设计时考虑不够周全,还需要进一步优化和改进,并且建议加大监测保护装置的健康水平和深度排查隐患,积累数字化变电站的日常运维和处理事故经验,提供同行借鉴。     

Absorption heat transformers and an industrial application

Absorption Heat Transformer (AHT) systems are devices with the unique capability of raising the temperature of low or moderately warm waste heat sources to more useful levels. The study includes an investigation to analyze the AHT systems using water-lithium bromide solutions with water as the refrigerant. First, a basic AHT system was described, the operating sequence was explained and thermodynamic system analysis was presented. Next, an application of the AHT system to an industrial company was analyzed. A computer code was prepared to determine the effect of different parameters on the AHT system performance and the results were presented in graphical form. Additionally, it was shown that how the basic AHT system could be modified to increase the COP and the heat transfer at the absorber, in other words, the hot process water produced. The system performance data were presented in a tabular form for different system modifications from the base system for comparison. It was proven that, by applying different modifications, the COP could be increased by 14.1%, the heat transfer at the absorber by 158.5% and the hot process water produced by 3.59% compared to the basic AHT system.     

Development and characterisation of electrochromic devices on polymeric substrates

The development of full solid-state electrochromic (EC) devices on polymeric substrate is underway within a CEC BRITE-EURAM project (Project “FREDOPS”, BE-4137) carried out by four industries, two universities and two research centers from Belgium, Denmark, France, and Italy. The specific goal of this project is to develop a Fast Response Electrochromic Device On Polymeric Substrate (FREDOPS); in order to satisfy the required range of specifications in terms of fast response, long term performance and high contrast ratio, several systems based on different materials have been tested. The full cells consist of an electrochromic material layer and a counter electrode, inserted between two PET/ITO layers and separated by a polymeric electrolyte. Different types of polymeric electrolytes, counter electrodes and electrochromic layers have been developed, studied and checked. Full devices have been assembled using different combinations. Voltammetric and spectrophotometric measurements have been executed to check the electrochromic behaviour of the developed layers in half and full cells. Comparison of the electrochromic performances of different materials based cells has led to the rejection of several solutions due to poor performance and incompatibilities between layers. Considering that the electrochromic devices are finalised for different uses (window, sunroof,…), some performance specifications for each application are defined. A testing bench for cycling and ageing was developed. The present paper discusses these results in order to indicate the best performance.     

Over 30% transparency large area inverted organic solar array by spray

We report the fabrication and characterization of large scale inverted organic solar array fabricated by all-spray process. The inverted polymer solar cell geometry consists of four layers, in the order of ITO-Cs₂CO₃-(P3HT:PCBM)-modified PEDPT:PSS, on a glass substrate. With semitransparent PEDPT:PSS as anode, the encapsulated solar array shows more than 30% transmission in the visible-near IR range. Optimization of device is done by thermal annealing, and the optimal annealing conditions are shown to be different in single-cell test device and the multiple-cell array. Solar illumination has been demonstrated to improve solar array efficiency up to 250%. Device efficiency of 1.80% was observed with the array under AM1.5 irradiance. Our preliminary data have shown that the performance enhancement under illumination only happens with sprayed devices, not devices made by spin coating. This means that solar cells made with our spray-on technique performs better under sunlight, which is beneficial for solar energy application.     

3#高炉煤气喷淋降温装置控制系统改造及应用

通过对重钢3#煤气喷淋降温装置的改造,介绍了喷淋装置的控制原理、组成、测量方式及现场的实际应用经验。将高炉产生的煤气通过在管道喷淋洒水进行降温后,保证了煤气管网出口温度满足后续工艺生产的要求。     

Degradation and annealing of amorphous silicon solar cells by current injection: experiment and modeling

In this paper we report in detail on the effect of current injection in amorphous silicon solar cells. A set of devices has been degraded and then annealed at different current intensities. Device performances during the whole experiment have been monitored by current–voltage characteristics and quantum efficiency curves. It has been found that annealing rate increases with current intensity, while stabilized photovoltaic parameters decrease. Time evolution of efficiency and short-circuit current during degradation has been reproduced by a numerical device modeling, resulting in a pronounced increase of defects near the p–i interface. The model also demonstrated that annealing results are not well reproduced if current-induced annealing is not energy selective.     

基于分形特征的海上风力机防护装置设计研究

根据分形理论设计一种分形防护装置,基于非线性动力学理论,采用ANSYS/LS-DYNA模拟5000 t船舶与设有不同阶数防护装置的4 MW海上风力机碰撞过程,分析研究不同阶数防护装置的防护效果。结果表明：较橡胶材料实心防护装置,分形防护装置可有效降低接触力,延长接触时间;分形结构可提高防护装置内能转化能力,促进外层钢壳吸能,并提升橡胶内能耗散;分形防护装置应力峰值更低,高应力区域更广,可使更大面积材料发挥防护作用,有效降低撞深。不同阶数分形结构的抗撞性能与分形孔受撞后变形状况有关,其中一阶分形结构提升防护装置抗撞性能最优。