馬云雙 周寧 宦榮華 高強(qiáng) 高國強(qiáng)
摘 要:通過近期對高速情況下弓網(wǎng)系統(tǒng)進(jìn)行深入研究,首先,對不同接觸網(wǎng)模型建模方法進(jìn)行了研究,并建立了4種接觸網(wǎng)波動特性的研究模型,辨識了不同接觸網(wǎng)模型結(jié)構(gòu)差異造成的波動特性變化,確定了該接觸網(wǎng)系統(tǒng)的波動特性,包括:波速、波長及頻率等;辨識了高速氣流擾動的特征,并通過對不同流固耦合仿真方法的研究,建立了弓網(wǎng)系統(tǒng)流固耦合聯(lián)合仿真方法。在此基礎(chǔ)上,對列車通過隧道以及接觸網(wǎng)風(fēng)振響應(yīng)進(jìn)行了相應(yīng)的分析;其次,在接觸網(wǎng)不平順方面,對受電弓底盤阻尼器和弓頭懸掛系統(tǒng)非線性進(jìn)行實驗測試和建模,同時,進(jìn)一步細(xì)化了基于梁單元的接觸網(wǎng)參變量有限元模型,從而可實現(xiàn)弦單元、梁單元、梁-弦混合模型的任意建模和數(shù)值仿真。針對接觸網(wǎng)的周期性特點,以精細(xì)積分方法為基礎(chǔ),建立了周期子結(jié)構(gòu)精細(xì)積分方法;在電接觸特性方面,構(gòu)建了弓網(wǎng)系統(tǒng)接觸區(qū)域有限元模型,研究了弓網(wǎng)間隙的電場分布及其隨振動間隙的變化規(guī)律,建立了弓網(wǎng)電磁力數(shù)值分析模型,研究了牽引電流、拉出值、振動間隙對弓網(wǎng)間電磁作用力的影響規(guī)律,分析了正常和瞬態(tài)短路工況下的弓網(wǎng)電磁作用力數(shù)值范圍,設(shè)計了高壓大電流弓網(wǎng)電接觸試驗系統(tǒng);最后,通過開展弓網(wǎng)間電弧放電特性和接觸網(wǎng)波動特性試驗研究,對理論研究工作提供了數(shù)據(jù)支撐。結(jié)果表明:采用多跨實際接觸網(wǎng)模型對波動特性研究較為合理,并通過弓網(wǎng)系統(tǒng)耦合仿真確定其接觸網(wǎng)的波速,進(jìn)而確定其頻率、波長特性的方法是可行的;當(dāng)列車通過隧道時,由于隧道壁面的限制,使得受電弓的氣動阻力和氣動抬升力較明線上運行增大,接觸線的動態(tài)抬升位移也相對增加,弓網(wǎng)受流質(zhì)量相對變差;接觸網(wǎng)在脈動風(fēng)作用下產(chǎn)生了較大的風(fēng)振位移和風(fēng)振應(yīng)力,有效控制風(fēng)荷載引起的接觸網(wǎng)位移和應(yīng)力對列車運行安全性十分重要;導(dǎo)高不平順的閾值,可為接觸網(wǎng)的架設(shè)、維護(hù)提供參考;在弓網(wǎng)耦合系統(tǒng)仿真中,接觸網(wǎng)承力索采用弦單元離散,接觸線采用梁單元離散,既可保證仿真結(jié)果的合理性,又能盡可能的保證計算效率;弓網(wǎng)電磁作用力受牽引電流影響較為顯著,正常工況下弓網(wǎng)電磁作用力較小,而短路工況下,弓網(wǎng)作用力迅速增大,對弓網(wǎng)動態(tài)特性影響較為顯著;弓網(wǎng)間產(chǎn)生的電弧對碳滑板的磨損率、弓網(wǎng)間摩擦副的接觸表面溫升的影響較大,導(dǎo)致電流發(fā)生畸變,對電路中的電器設(shè)備造成不利影響。
關(guān)鍵詞:弓網(wǎng) 不平順 電接觸 振動特性 波動
Abstract:Pantograph and catenary system are comprehensively investigated at high speed. Firstly, different models of the catenary are established to determine the wave characteristics for this catenary. Then,the co-simulation method of fluid-structure coupled analysis for pantograph-catenary system is established. The trains passing through the tunnels and the wind-induced vibration of catenary are analyzed. Secondly, by experimental testing on the pantograph bottom damper and the pantograph head suspension system, the nonlinear characteristic curves and the corresponding mathematical models are obtained in the catenary irregularity research. Meanwhile, for numerical simulation of pantograph-catenary coupled system, the accuracy and efficiency are both satisfied if the string element is used for catenary messenger wire and the beam element is used for contact wire. In electrical content aspect, electrical field distribution and its relationship to vibration gap have been studied. Relationship among traction current, vibration gap, stagger and electromagnetic force has been studied. Finally, pantograph-catenary arc and catenary wave characteristics experiment has been conducted for supporting the theoretical research. It is demonstrated that investigating the wave characteristics of the catenary by using the actual catenary model with multiple spans is reasonable, and it is effective to determine the wave characteristics through the simulation of pantograph and catenary coupled system. Due to the effect of tunnel wall confinement, the aerodynamic drag, lift forces of pantograph and uplift displacements of the contact wire are increased. It is important to effectively control the displacements and stresses of catenary induced by the wind loads. On the other hand, catenary irregularity threshold provides reference for catenary installation and maintenance. For simulation of pantograph-catenary coupled system, the accuracy and efficiency are both satisfied if the string element is used for catenary messenger wire and the beam element is used for contact wire. Electromagnetic force is small in normal situation. But it will enlarge rapidly in short circuit and affects dynamic features of pantograph-catenary obviously. Pantograph- catenary arc has large influence on wear rate of carbon slipper and contact surface temperature rise, lead to current distortion of circuit for affecting the electrical equipment adversely.
Key Words:Pantograph-catenary;Irregularity;Electrical contact;Dynamic characteristic;Wave propagation
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