【作者】 王耀利；

【导师】 张炳达； 张智新；

【作者基本信息】 天津大学 ， 电气工程， 2008， 硕士

【摘要】 我国的电力机车大部分是整流型电力机车,电力机车通过机车变压器和硅整流器组获得所需直流电,供给牵引电动机使用。用于整流的电力电子器件会产生谐波,造成接触网电流畸变。此外,机车制动时,不再从电网吸收能量而是进行再生制动。如果能充分的利用这部分再生电能,则可获得很好的节能效益。于是,本文探讨一套既能消除接触网上的谐波,又能将电力机车再生制动时产生的再生电能回馈利用的装置。这套装置安装在电力机车内部,与电力机车的硅整流器组反并联。有源电力滤波器是本文研究的重点。谐波检测技术是有源电力滤波器的关键技术之一。文中介绍一种将自适应噪声对消技术与自适应线性神经网络理论相结合研究了自适应神经网络谐波电流检测方法。详细介绍自适应线性神经网络理论及其核心算法——LMS算法。在理论分析的基础上,同样进行大量仿真研究。该方法在负载电流发生变化和电网电压改变时,可以很好的自适应跟踪检测。但高检测精度和快响应速度很难一致,这主要与该方法的学习速率有关。于是本文构建一个变学习速率的谐波电流仿真模型,仿真结果表明这种变学习速率的检测方法不仅具有很高的检测精度,而且具有很快的动态响应速度。有源电力滤波器的另一关键技术是PWM控制方式。本文的控制方式采用三角载波PWM方法,分析了单极性PWM法的工作过程。并对有源电力滤波器进行仿真研究,给出仿真结果。仿真结果证实单相有源电力滤波器能够消除谐波,净化电网。更多还原

【Abstract】 Most domestic electric locomotives are of rectifier. The electric locomotive gets DC supply to drive traction electromotor through a locomotive’s transformer and a set of silicon rectifiers. But rectifier may produce harmonic current and distort the current of contact-grid. Moreover, when the locomotive operates in the regenerative brake mode, it doesn’t draw but produce regenerative braking current. If the regenerative energy is utilized well, much of energy is saved. So a device anti–parallel connected with locomotive’s silicon rectifier is discussed, which can eliminate harmonic current and inject regenerative energy to the AC grid.Active power filter is the main issue in this paper. Harmonic detection is one of key technologies of active power filter. An adaptive neural network harmonic current detecting method, based on the adaptive noise eliminiting technology and the adaptive linear neural network theory, is discussed. The adaptive linear neural network theory and its core algorithm——LMS algorithm are introduced in detail. On the base of theoretical analysis, a number of simulations are developed. When load currents and the grid voltage change, the detecting method is well adapted. But high detecting precision and rapid dynamic response hardly achieve at the same time, because of the influence of learning speed. So a harmonic current simulation mode is set up. Its learning speed is variable. The results of simulation show that the detecting method is of both high detecting precision and rapid dynamic response.Pulse width modulation (PWM) control method is another key technology of active power filter. Triangle carrier wave PWM control method is adopted in the paper, and the running process of unipolar PWM control method is analyzed. The simulation for active power filter is developed. The results prove that the proposed single-phase active power filter can eliminate harmonic current and purify the supply grid.更多还原