【作者】 薛彭雨；

【导师】 李群湛；

【作者基本信息】 西南交通大学 ， 电气工程， 2013， 硕士

【摘要】 我国电气化铁路采用单相工频牵引供电系统,并利用分段换相供电的方式来平衡电力系统的三相负荷。为了防止异相短路并保证机车能顺利通过电分相,电气化铁路接触网上每20-30km就要装设一个电分相装置。如采用手动过分相方式,机车能否顺利通过电分相,依赖于司机的操作以及道路指示信号的可靠性。而一旦出现司机误操作或信号指示错误,就会造成机车带电闯分相,可能导致电弧烧毁承力索或受电弓设备等,这将严重影响牵引供电系统的安全运行。所以,电气化铁路适合采用自动过分相装置。目前应用比较广泛的自动过分相方案有：车载自动过分相和地面自动过分相。在实际使用中,由于机车在通过电分相时,由于引起了系统参数的变化,经常发生过电压、过电流等现象,也非常影响电气化铁路的安全运营。因此,机车过电分相装置的研究具有较高的理论意义和实际价值。本文提出一种新型阻尼式自动过分相方案,即在分相处加入星型电阻器组,利用星型电阻器组的阻尼作用来抑制机车过分相过程中出现的暂态过电压。首先,对本方案的基本原理、控制策略和特点进行介绍。其次,由于电阻器组阻值越大,无机车通过时稳态损耗越小,但是对于过电压等暂态现象的抑制作用也越小。所以,为了保证本方案在无机车通过时星型电阻器组的稳态损耗较低,并保证对暂态现象的抑制作用,对阻值的合理选择进行分析。再次,通过对电力机车通过电分相过程的电气计算,从理论方面验证方案对过电压、过电流等暂态现象的抑制的有效性。最后,利用Matlab/Simulink软件,通过建立的电力机车模型和机车通过电分相过程模型,对机车与左供电臂脱离、与右供电臂接触和整个过分相过程进行仿真。通过对仿真结果的仿真和总结,验证新型阻尼式自动过分相方案抑制暂态现象的有效性。基于新型阻尼式自动过分相方案利用电阻器组阻尼作用来抑制过电压的原理,本文介绍另一种利用阻尼作用来抑制过电压的方案,即：在锚段关节过分相中性段上加入对地电阻,并通过仿真验证它的有效性。更多还原

【Abstract】 Single-phase,50Hz AC power system is applied in Chinese electrified railway. Different phase in rotation is used to balance the three-phase load of power system. In order to prevent short circuit between diffrent phases and make sure the locomotive pass by smoothly, phase-separations are set every20to30kilometer. If we take manual mode of passing over of neutral section, the driver’s operation and the reliability of the road signal instructions determine whether the locomotive can pass the phase-separations or not. Once negligence, it will cause charged cross the phase-separation, and influence of the traction power supply system safety operation. So the auto-passing device is necessary in the electrified railway. The on-board neutral-section auto-passing device and the ground auto-passing device are widely used at present. In the actual application, there are some changes of the system paramater when the locomotive passes the phase insulator. It can cause over-voltage and flow, and it seriously affects the electric railway’s safe operation. So the study of scheme about auto-passing neutral device has the theoretical and actual value.The paper presents a new scheme about damping auto-passing neutral section, which adds a Y-type resistors bank on the phase-separations. It uses the damping effect of the Y-type resistors bank to reduce the transient over-voltage which appears when the locomotive passes the phase insulator. First, the paper introduces the work principle and the control strategy and the feature. Secondly, the steady state loss will decrease and the damping effect of the Y-type resistors bank will weak when the resistance of the Y-type resistors bank increase. For the purpose of reducing the steady state loss and ensuring the damping function, the paper analysis the way of how to choose the resistance of the Y-type resistors bank reasonably. Thirdly, the paper proves the scheme is effective in reducing the over-voltage and flow by electrical calculation about the process of locomotive passing the phase insulator. Finally, the Matlab/Simulink software is used to establish the locomotive model and the model of the locomotive passing the phase insulator. Then the models of the locomotive separating from the left feeding section, contacting to the right feeding section, and the whole process of the locomotive passing the phase insulator are simulinked. The simulation waveforms are analyzed and sumarized, which validate the effectiveness of the new scheme about damping auto-passing neutral section to reduce the over-voltage and flow. Based on the principle, which the resistors are used to reduce the over-voltage of the new scheme about damping auto-passing neutral section, the paper introduces another scheme to reduce the over-voltage. It adds a bank of resistors to ground on the neutral section of the on-board neutral-section auto-passing device. Simulations are taken to validate the effectiveness of over-voltage reducing.更多还原