简介:摘要:变压器因接线组别导致各侧间电势相位产生一个角度差;变压器各侧电压、电流互感器变比不同,各侧电流幅值也不同。所以变压器差动保护装置在对电流采样进行差动计算前,需对各侧采样电流进行方向折算和幅值折算。变压器差动保护装置厂家较多,装置原理、动作特性平面坐标定义各不一致,对初学者来说有点混杂。现场调试可以单相加量或三相加量,本文对比各装置折算类型,总结对应的现场调试接线和加量方法。调试结果计算时,只需按装置折算过程,得出差动计算因数,根据装置说明书将因数代入对应制动电流、动作特性平面横坐标定义公式,即得出动作特性平面坐标点,实现装置校验的目的。
简介:Inordertostudytheeffectsofgeometricparametersoftherudderonthehydrodynamicperformanceofthepropeller-ruddersystem,thesurfacepanelmethodisusedtobuildthenumericalmodelofthesteadyinteractionbetweenthepropellerandruddertoanalyzetherelevantfactors.Theinteractionbetweenthepropellerandrudderisconsideredthroughtheinducedvelocities,whicharecircumferentiallyaveraged,sotheunsteadyproblemistranslatedtosteadystate.Aniterativecalculationmethodisuseduntilthehydrodynamicperformanceconverges.Firstly,thehydrodynamicperformanceofthechosenpropeller-ruddersystemiscalculated,andthecomparisonbetweenthecalculatedresultsandtheexperimentaldataindicatesthatthecalculationprogramisreliable.Then,thevariableparametersofrudderareinvestigated,andthecalculationresultsshowthatthepropeller-rudderspacinghasanegativerelationshipwiththeefficiencyofthepropeller-ruddersystem,andtherudderspanhasanoptimalmatchrangewiththepropellerdiameter.Futhermore,therudderchordandthicknessbothhaveapositivecorrelationwiththehydrodynamicperformanceofthepropeller-ruddersystem.
简介:摘要:飞机舵面主要是在气流中飞行控制系统的液压作动子系统操纵舵面偏转而产生控制力来操作飞行的气动翼面。开缝式舵面飞机外翼后缘增升装置分为襟翼和襟副翼,襟翼、襟副翼在结构形式上采用了开缝襟翼,舵面面积和迎风面积增大,从而缩短了滑跑距离。本文主要通过分析缝翼操纵系统运动原理,确定了一种缝翼角度的调节方法,从而保证缝翼偏转角度。
简介:Anovelclassofintelligentpower-assistsystemsbasedondifferentialCVT;Developmentofhigh-strengthcasehardeningsteel;DevelopmentoftorquesensingLSDwithconeclutchaimingatsmallersizeandlighterweight;EffectofCoreHardnessandCaseDepthonLow-Cycle-Impact-FatiguePropertyinCarburizedSteel;EffectofcorehardnessandECDonlow-cycle-impact-fatiguepropertyincarburizedsteel……