220 kV线路U型挂环断裂故障分析

采用断口宏观检查、化学成分分析、硬度检测、金相组织分析、金具载荷计算和扫描电镜分析等手段，对某220 kV线路U型挂环断裂的原因进行了分析。结果表明，高铁通过时地线存在电流通过，U型挂环与线夹钢锚接触不良发热进而发生高温磨损，长期运行后最终导致断裂失效。     

配电台区高低压设备典型故障分析

选取一例典型的配电台区高低压设备综合缺陷引发烧损故障进行深入剖析,从配电台区运行管理、保护设备配置、安装工艺管控等方面挖掘出当前存在的严重问题。在此基础上,针对性提出高效可靠的解决方案,着力提升配电设备运行水平。     

The assessment of the fuel additive impact on moving grate boiler efficiency

The purpose of the work is to determine the impact of a commercial coal additive on the efficiency and the pollutants emissions of an industrial boiler. The tests were carried out in a 41.1 MW thermal output moving grate boiler in common operating conditions for a period of two months. At that time, coal was alternately dosed with and without the additive. The amount of the additive to coal ratio was fixed at 1L/Mg during the tests. The additive applied was a 20% aqueous solution of four compounds, i.e. isopropanol, manganese (II) acetate tetrahydrate, acetic acid glacial … % and N,N-Dimethylethanolamine.The samples of coal, bottom and fly ash were collected from the installation twice a day during the tests in order to check their properties. The boiler's main energy parameters and the emission levels of CO, NO_x, SO₂ and dust were measured and registered. The additive influence on the boiler operation was evaluated based on the efficiency and three indicators which highlighted this impact.The additive influence was mainly demonstrated in boiler efficiency increase, in the range of 0.5–1 p.p., as well as the oxygen concentration in the flue gas which indicates that there was a decreased amount of the combustion air. On the other hand, the studies do not show any evident influence on the NO_x, SO₂ and CO emissions with the applied catalyst to fuel ratio. The research showed that even a little improvement of efficiency gives a measurable economic effect.     

±500 kV伊穆直流接地极址在线监测系统设计

为提高±500 kV伊穆直流接地极址运维智能化水平、及时掌握接地极的运行状况、提高直流工程的安全性,提出并实现了±500 kV伊穆直流接地极址在线监测系统。该系统前端监测单元能够实时监测温湿度和接地极入地电流,同时对现场环境进行视频监测;通过远距离无线数据传输,将前端监测到的数据反馈到后台控制系统;后台控制系统将硬件系统采集的各种数据经过计算以合理的方式显示供操作人员参考,并进行状态诊断和故障自动报警。     

一种光储独立并网式虚拟同步发电机控制方法

以光储独立并入电网的虚拟同步发电机结构为研究对象,提出考虑储能输出功率限制的有功调节方案和光储共同参与电压调整的无功调节方案。在有功功率环,当储能系统的充放电功率达到上限时,通过附加控制调节机械转矩,稳定虚拟同步发电机控制方程,避免储能过充或过放风险。在无功功率环,光伏系统与储能系统共同承担无功调压任务,减轻储能系统的无功功率输出负担,实现无功功率合理分配。最后,通过仿真分析和RT-LAB实验结果验证了该控制策略的正确性和有效性。     

智能微型断路器抗强磁干扰技术

针对智能微型断路器在强磁干扰情况下容易出现误动和拒动的问题,对可能造成磁干扰的智能微型断路器操控系统、直流电机、开关电源等相关模块进行了分析,并提出了具体的优化设计方案。提出了基于微动开关与霍尔开关双模检测相结合的操控系统抗磁干扰优化设计方法,并从硬件和软件2方面加以实现。提出了直流电机抗磁干扰优化设计方法和开关电源输出功率抗磁干扰优化设计方法,提高了直流电机和开关电源抗磁干扰的能力。实验表明,经优化后的智能微型断路器抗磁干扰性能优越,稳定性、可靠性高,解决了智能微型断路器在强磁干扰情况下容易出现误动和拒动的难题,具有推广应用价值。     

Gasification of preheated coal: Experiment and thermodynamic equilibrium calculation

A new process integrating a circulating fluidized bed (CFB) reactor and an entrained bed reactor was proposed for gasification of preheated coal. The CFB reactor as a preheater was successfully used in clean coal combustion. In this study, gasification of preheated coal was tested in a bench-scale test rig, which consisted of a CFB preheater and a down flow bed (DFB) gasifier. The effects of operating parameters of the preheater and gasifier were revealed via thermodynamic equilibrium calculations. A stable preheating process was obtained in the CFB preheater at the O₂/C molar ratio of 0.31 and higher gasification reactivity was gained in preheated char owing to the improvement in intrinsic reactivity, specific surface area and total pore volume. Effective gasification of preheated char was achieved in the DFB gasifier at 1100 °C and the total O₂/C molar ratio of 0.67, meanwhile the CO + H₂ yield and carbon conversion increased. Thermodynamic equilibrium calculations revealed when the gasification reaction rates varied little above 1100 °C and the same carbon conversion was achieve in gasifier, lowering the temperature would lead to an increase in cold gas efficiency and a decrease in O₂ demand.     

Positive temperature coefficient of resistivity in thin films of barium titanate

One of the perspective directions in using positive temperature coefficient (PTC) thermistors is their application in surface heater in various electronic devices and integrated circuits. The special interest in this connection makes possible fabrication of thin film structures on the basis of materials with PTCR. In the given work a result of the investigation of Y–BaTiO₃ thin films has been presented. Thin films have been deposited by RF-sputtering technique. Films had thickness of 1.5–2 μm. Subsequent annealing was carried out to obtain polycrystalline films of a single phase. The temperature dependence of resistance of films has been investigated. The increase of the resistance were observed in the temperature range 50–80°C. The jump of the resistance in field of phase transition was 70%.     

考虑含多敏感负荷的配电网电压暂降脆弱区域辨识方法研究

随着变频器和继电器等大量敏感负荷的应用,电压暂降问题愈发成为了配电网尤其是敏感负荷占比很高的现代工业配电网亟需解决的动态电能质量问题。为有效评估配电网中易引发电压暂降的薄弱环节与指导电压暂降补偿方案的设计,提出了考虑多个敏感负荷的配电网电压暂降脆弱区域的辨识方法。首先,通过引入母线暂降判定向量与线路暂降关联向量以及相应的判定准则,确定了目标配电网中临界点在各线路上的分布以及各临界点的位置。其次,基于获得的敏感负荷的电压暂降域,得到了考虑交叠效应的配电网电压暂降域层级模型,并由此定义了电压暂降影响度以实现对配电网内电压暂降脆弱区域的量化评估。最后,将所提方法应用于IEEE14母线系统电压暂降脆弱区域辨识,验证了所提方法的可行性与合理性。     

考虑储能系统动态全寿命周期特性的多功能应用需求规划方法

为充分发挥配电网中电池储能电站（battery storage power station, BSPS）调峰、调压和改善系统可靠性等多功能特性。提出了一种以削峰填谷为主,同时兼顾调压、新能源消纳等多功能应用需求的规划方法。该方法旨在使经济效益目标最大化的同时,确定BSPS的位置、功率和容量。为使结果更加准确,考虑电池老化影响,将BSPS分成建设、运行、衰退等多时段,构建动态全寿命周期模型,并采用量子遗传算法求解。算例分别对干线和环网2种不同结构,以峰谷差大、电源、负荷分布不均衡的某省实际电网数据为例,验证了所提规划方法的有效性。