矿用电机驱动变频器电磁兼容及其安全性关键技术研究

发布时间：2018-06-03 19:30

本文选题：矿用变频器 + 电磁兼容　；参考：《华北科技学院》2015年硕士论文

【摘要】：随着煤矿电气设备，敏感电子仪器的不断增多，井下电气设备的谐波传导干扰及辐射干扰等问题的研究变得越来越重要，但目前相关的研究工作还很不够深入，尤其是对于主要电磁干扰源矿用变频器的研究还很不足，相关的标准和规范还不够完整，这严重制约着煤矿电气设备技术升级，更新换代的脚步。本文围绕矿用变频器在使用时带来的电磁兼容性问题，对目前国内外关于矿用变频器的行业标准及研究成果进行了综述，基于前人的研究成果对矿用变频器的主回路谐波进行了补充性的理论和仿真实验研究，并对目前常用的一些滤波措施进行了探讨和设计。其中谐波方面主要基于双重傅里叶分析方法对目前常用的SPWM和SVPWM两种类型矿用变频器的输出差模电压进行了谐波频谱分析，揭示了输出侧谐波在载波带和基波带的分布规律。为分析输出谐波对矿用电机安全运行的影响，建立了矿用异步电机的等效电路模型，研究了变频器输出侧高次谐波对异步电机的转矩特性的影响。通过对矿用变频器中常用的晶闸管、二极管和PWM整流结构网侧电压和电流进行谐波比较，分析了矿用变频器整流部分四象限改造对于改善其谐波性能的必要性，并在理论分析的基础上对PWM四象限整流器网侧谐波进行了研究，结合频谱分析结果对双PWM变频器网侧电感进行了参数设计和仿真实验分析，为减小对变频器与煤矿电网之间的相互干扰，提出了在网侧加装隔离变压器进行电气隔离的建议。为提高矿用变频器的抗干扰性，减小其漏电给人员操作带来的不安全因素，其控制系统、主回路及外壳一般都需要采取良好的接地措施，本文针对传输线及外壳安全接地和电磁兼容接地两方面对矿用变频器的接地措施进行了研究和分析，通过这些措施可以很好的减小变频器在电磁兼容方面的维护成本，提高其运行时的安全可靠性。矿用变频器作为一种在爆炸危险性环境中使用的电气设备，一般都装有隔爆外壳，厂商在设计隔爆外壳的过程中，一般仅考虑其在抗压和隔爆等方面的性能，但对隔爆外壳在电磁辐射屏蔽方面的所起的作用考虑的较少，而矿用变频器隔爆外壳一般都会存在孔缝，这就给电磁辐射的泄漏带来了途径，本文通过建立理论和仿真模型，，研究了屏蔽体对高频电磁辐射的屏蔽效应，针对隔爆外壳孔缝密封措施提出了一些建议，对隔爆外壳的设计起到了一定的指导作用。
[Abstract]:With the increasing number of electrical equipment and sensitive electronic instruments in coal mine, the research on harmonic conduction interference and radiation interference of underground electrical equipment becomes more and more important, but the related research work is not deep enough. Especially for the main electromagnetic interference source mine frequency converter research is still very insufficient, related standards and specifications are not complete, which seriously restricts the technical upgrading of coal mine electrical equipment, the pace of upgrading. This paper summarizes the industry standards and research results of mining frequency converters at home and abroad, focusing on the problems of electromagnetic compatibility (EMC) brought about by the use of mine frequency converters. Based on the previous research results, this paper makes a supplementary theoretical and simulation study on the harmonic of the main loop of the mine frequency converter, and discusses and designs some commonly used filtering measures. In the aspect of harmonics, the harmonic spectrum analysis of the output differential mode voltage of two types of mine frequency converters, SPWM and SVPWM, is carried out based on the method of double Fourier analysis, and the distribution of the output side harmonics in the carrier band and the fundamental band is revealed. In order to analyze the influence of output harmonic on the safe operation of mine motor, the equivalent circuit model of mine asynchronous motor is established, and the influence of high order harmonic on the torque characteristic of induction motor is studied. By comparing the voltage and current of thyristor, diode and PWM rectifier, the necessity of improving the harmonic performance of the rectified part of mine inverter is analyzed. On the basis of theoretical analysis, the harmonic on the grid side of PWM four-quadrant rectifier is studied, and the parameter design and simulation experiment of the inductance of double PWM converter are carried out in combination with the result of spectrum analysis. In order to reduce the mutual interference between frequency converter and coal mine power network, the suggestion of installing isolating transformer on the grid side for electrical isolation is put forward. In order to improve the anti-interference of mine frequency converter and reduce the unsafe factors brought about by the leakage of electric current, it is necessary to take good grounding measures for its control system, main circuit and shell. In this paper, the grounding measures of mine frequency converter are studied and analyzed in terms of transmission line and shell safe grounding and electromagnetic compatibility grounding. Through these measures, the maintenance cost of frequency converter in electromagnetic compatibility can be reduced very well. Improve the safety and reliability of its running time. As a kind of electrical equipment used in explosive dangerous environment, mine frequency converter is usually equipped with flameproof casing. In the process of designing flameproof shell, the manufacturer generally only considers its performance in the aspects of pressure resistance and flameproof. However, the effect of flameproof shell on electromagnetic radiation shielding is less considered, while the flameproof shell of mine frequency converter usually has holes, which brings a way to the leakage of electromagnetic radiation. In this paper, a theoretical and simulation model is established. The shielding effect of shield on high frequency electromagnetic radiation is studied, and some suggestions are put forward for the sealing measures of flameproof shell hole, which plays a certain guiding role in the design of flameproof shell.
【学位授予单位】：华北科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD614

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