【作者】 刘勇；

【导师】 何湘宁；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2006， 博士

【摘要】 大气压下的等离子体可以分为热平衡等离子体和非热平衡等离子体,非热平衡等离子又称低温等离子体,它的特点是电子温度远高于重粒子温度。近年来,对低温等离子体的研究逐渐成为等离子体学科的研究热点。其主要原因是低温等离子体在许多工程领域,特别是在材料表面改性方面具有重要的应用价值。低温等离子体材料表面处理不仅可以使材料表面变粗糙,并且可以引入羟基（—OH）,羰基（—C=O）,氨基（—NH₂）等亲水基团,从而提高材料的表面能,改善材料表面的润湿性和粘结性。 目前电力电子技术已广泛地应用于低温等离子体的材料表面处理,但由于现有的高压低温等离子体放电电源系统的低效率和高成本,严重影响了它的进一步推广。研究一种适合多种材料负载的高效低温等离子体表面处理系统已成为必然。本文的研究是低温等离子体科学、电力电子技术和材料科学的交叉学科研究,因此本文的主要研究内容也包括了这三方面。 1、对介质阻挡放电的影响因素进行了系统地分析和研究。 a) 首次确定了接地电极转动对介质阻挡放电的影响。实验的结果表明:接地电极静止或转动,介质阻挡放电将呈现不同的放电形式和电流波形,对其原因进行了讨论。 b) 讨论了不同电极结构和不同放电形式的介质阻挡放电的特点。提出了一种采用介质阻挡放电的电极结构,在空气中产生大气压下均匀放电的方法。 c) 详细分析了绝缘介质位置不同对介质阻挡放电电流波形的影响和绝缘介质对放电起始电压的影响,并对绝缘介质对介质阻挡放电特性的影响进行了分析和总结。 2、通过大量的仿真和实验,详细分析了介质阻挡放电的负载特性。分别给出了变压变频、定频变压、和定压变频的动态变化曲线,并通过20kW塑料薄膜表面处理机的研制对分析结果进行了验证。在此基础上设计了一系列不同功率等级和不同控制方案的低温等离子体放电电源,满足不同应用场合的需求。 a) 提出了一种基于脉冲密度调制（PDM）和脉冲频率调制（PFM）混合控制的材料表面处理电源。PDM用来调节逆变器的输出功率,PFM用来补偿温度和其它环境因素对放电的影响。实验结果表明基于PDM和PFM混合控制的串联谐振逆变器（SRI）使材料表面处理电源系统简单,更多还原

【Abstract】 Atmospheric pressure plasmas are subdivided into the non-thermal and thermal ones. The non-thermal plasmas are so-called the low temperature plasmas. The conditions of low temperature plasmas are mainly characterized by a relatively low temperature of the neutral gas in contrast to a significantly higher temperature of the electrons. The low temperature plasmas technologies have been paid much attention in recent years, due to their prospective applications in industry, especially in the material surface modifications. The low temperature plasmas not only etches the surface, making it rough, but also incorporates hydrophilic functionalities such as -OH, -C=O, -NH₂, etc. It can increase the surface energy of the materials. The modified surface shows good wettability and bondability.Presently, the power electronics technology has been widely used in the low temperature plasma discharge surface treatment. However, the low efficiency and high cost of existing low temperature plasma discharge power sources have prevented it from application. Accordingly, the research and development of efficient low temperatures plasma discharge surface treatment system suitable for various kinds of material loads becomes inevitable. The research field in this paper is interdiscipline, including the low temperature plasma science, power electronics, and material science. So, the research contents of this paper include the three subjects.1 、 This paper analyses the related factors of dielectric barrier discharge（DBD）.a) The effect of the rotating grounding electrode on dielectric barrier discharge is determined. The experiment results indicate that the dielectric barrier discharge will show different discharge forms and current waveforms by still or rotating grounding electrode. The reason is discussed in this paper.b) The characteristics of the different electrode geometries and the different discharge modes of dielectric barrier discharge are discussed. A method to generate an atmospheric pressure uniform discharge with the electrode geometric of the DBD is presented.c) The influences of the dielectric barrier in different place on the discharge current and the influences of the dielectric barrier on the discharge starting voltage are analyzed in detail. The influences of the dielectric barrier on the characteristics of DBD are analyzed and summarized.2 -, Based on a lot of simulations and experimentations, this paper comprehensively analyzes the characteristics of dielectric barrier discharge loads thoroughly. The dynamic curves of variable voltage variable frequency, constant frequency variable voltage and constant voltage variable frequency are given respectively. Experiments are carried out to verify the validity of analysis. A series of different rated power low temperature plasma power systems by different control methods are designed for using in different situationsa) A dielectric barrier discharge surface treatment based on a pulse density modulation （PDM） and pulse frequency modulation （PFM） hybrid control scheme is presented. The PDM scheme is used to regulate the output power of the inverter and the PFM scheme is used to compensate for temperature and other environmental influences on the discharge. The experimental results show that the PDM and PFM hybrid control series-resonant inverter （SRI） makes the DBD treatment simple and compact, thus leading to higher efficiency. The hybrid control SRI is able to realize the constant frequency control and linear power adjustment, and is thus becoming an ideal choice for dielectric barrier discharge treatment.b) A high frequency and high voltage power supply is essential for material surface treatment. In general, the dielectric barrier discharge processes require specifically designed ac power supplies of 10-20kV, 10-30kHz, and l-50kW to maintain a stable discharge at the atmospheric pressure. In order to ensure the capability of adjusting the affinity adaptability according to various kinds of materials with different thickness requires an ac power supply capable of controlling the discharge power in a wide range. To meet domestic needs, the l⁵0kW, 20kV, 20kHz dielectric barrier discharge inverter based on PAM control is developed. It can realize the soft switching conditions for the IGBTs, and also be adapted to the variety of discharge loads.c) The dielectric barrier load is represented as a varied nonlinear capacitance load, and its equivalent capacitance becomes higher as the applied voltage increased. A phase-shifted pulse width modulated （PS-PWM） series resonant inverter is developed for plastic film surface treatment, with such the characteristic of the load, and the tracing of the load resonant frequency is realized with a close-loop control.d) The characteristics of atmosphere pressure glow discharge loads areanalyzed, and the load resonant frequency of atmosphere glow discharge changes with the applied voltage nonlinearly. Based on the analysis and comparison of the control methods in experience, a PDM controlled atmosphere glow discharge high frequency and high voltage power source is presented. The PDM control series resonant inverter can meet the requirement of atmosphere glow regulation in the whole output power range.3> The high-frequency, high-voltage discharge power source developed in this paper is practically used in the surface treatment.a) Surface modifications of the organic material and inorganic material are achieved by the DBD. The experimental results are given.b) The related factors of the polymeric materials surface modification are analyzed in detail.c) The flammable wool fibers are surface treatment by the dielectric barrier discharge and atmospheric pressure glow discharge respectively. The analysis and experimental results show that the filamentary discharge is not suitable for the surface treatment of the flammable wool fibers, but the atmospheric pressure glow discharge can accomplish the task very well.更多还原