In order to resolve the problems of machining non-axisymmetric aspheric lens,which is short of flexibility in mould grinding and needs high accuracy CNC machine center in globediamond wheel grinding, a new parallel gr...In order to resolve the problems of machining non-axisymmetric aspheric lens,which is short of flexibility in mould grinding and needs high accuracy CNC machine center in globediamond wheel grinding, a new parallel grinding method that utilizes common arc diamond wheel isput forward. Base on the approach calculation of machining locus, the advantages of parallelgrinding that machines non-axisymmetric aspheric lens by 2.5-axis CNC machine center have beenobtained. The results of grinding experiment show the new method can meet the need of grinding highaccuracy non-axisymmetric aspheric lens.展开更多
高压直流断路器(Direct Current Circuit Breaker,DCCB)需承载直流线路正常工作时的工作电流,且需在规定时间内接通分断直流线路正常工作时的电流,以及分断直流线路短路故障电流。高压DCCB是确保高压直流输配电网安全、可靠运行的基础...高压直流断路器(Direct Current Circuit Breaker,DCCB)需承载直流线路正常工作时的工作电流,且需在规定时间内接通分断直流线路正常工作时的电流,以及分断直流线路短路故障电流。高压DCCB是确保高压直流输配电网安全、可靠运行的基础。混合式高压DCCB既具备机械式高压DCCB的优点,也具备固态高压DCCB的优点。在分析了各类混合式高压DCCB的拓扑、工作原理基础上,总结了混合式高压DCCB的设计关键技术,如电弧数学模型、串联均压、并联均流等问题。展开更多
基金This project is supported by Provincial Foundation for Young Scientists & Scholars Innovation of Fujian, China (No.0013K13004).
文摘In order to resolve the problems of machining non-axisymmetric aspheric lens,which is short of flexibility in mould grinding and needs high accuracy CNC machine center in globediamond wheel grinding, a new parallel grinding method that utilizes common arc diamond wheel isput forward. Base on the approach calculation of machining locus, the advantages of parallelgrinding that machines non-axisymmetric aspheric lens by 2.5-axis CNC machine center have beenobtained. The results of grinding experiment show the new method can meet the need of grinding highaccuracy non-axisymmetric aspheric lens.
文摘多端直流输电技术可有效缓解中国输电走廊紧缺问题,并解决大规模的清洁能源并网,通过配置直流高速开关(high-speed switch,HSS),可实现多端直流系统第三站的在线投退及直流线路故障快速隔离。但目前国内缺乏±800 kV HSS设备的制造技术与试验经验。为掌握核心技术,文中首先简要介绍多端直流输电工程对HSS的功能需求,提出HSS的运行工况及关键技术参数。其次,着重介绍研制±800 kV HSS特殊性能验证试验,包括长时燃弧耐受关键技术及无震荡回路开断直流关键技术及其研究现状,提出了±800 k V HSS关键性能的考核方法和型式试验要求,并对其下一步的研究方向给出了建议。
文摘高压直流断路器(Direct Current Circuit Breaker,DCCB)需承载直流线路正常工作时的工作电流,且需在规定时间内接通分断直流线路正常工作时的电流,以及分断直流线路短路故障电流。高压DCCB是确保高压直流输配电网安全、可靠运行的基础。混合式高压DCCB既具备机械式高压DCCB的优点,也具备固态高压DCCB的优点。在分析了各类混合式高压DCCB的拓扑、工作原理基础上,总结了混合式高压DCCB的设计关键技术,如电弧数学模型、串联均压、并联均流等问题。
