纳秒脉冲射流阵列放电及提高绝缘沿面耐压研究

The performance of insulation systems are limited by flashover discharge along the surface of insulating materials, which restricts the overall performance of electric equipments and systems, so it is of great important to find ways to improve the surface flashover hold-off voltage of insulating material. The using of atmospheric pressure non-thermal plasma to modify the surface hydrophobicity of insulating materials to improve their surface flashover hold-off voltage is put forward in this project. Using F/Si as reaction medium and He/Ar as working gases, high active plasma jet is generated by using high voltage repetitive nanosecond-pulse excitation, and jet arrays of linear type and honeycombed type will be designed to treat uneven insulating surface. The influences of discharge parameters, electrode arrangements and treatment mediums on the discharge characteristics, coupling, uniformity and stabaility mechanism of the jet arrays will be studied, and the conditions and parameters for generating the stable and uniform discharge will be determined. The influences of treatment paprmeters on surface peroperties and surface peroperties on surface flashover performance will be analyzed, and super-hydrophobic surface with contact angle large than 150 degrees and the surface conditions with optimal surface flashover performance will be obtained. Through multi-parameter measurements, the cooperation correlative relationships among discharge parameters, surface peroperties, and surface insulation performance will be established, and the technological methods for reliable controlling the surface modifications will be proposed, with the mechanism of generating the high active plasma and using it to improve surface flashover performance being explored. This research is of great interest for promoting the applications of atmospheric pressure plasma sources, improving the surface performance of insulating materials, and optimizing the insulation systems of electric equipments.

绝缘系统的性能受绝缘材料表面沿面闪络现象所限制，严重制约了电气设备及系统整体性能，探索提高绝缘材料表面耐压强度至关重要。本项目提出采用大气压等离子体对绝缘材料表面进行憎水改性来提高沿面耐压性能，以F/Si等为反应媒质、He/Ar等为工作气体，采用重复频率纳秒脉冲激励产生高活性等离子体，设计直线型/蜂巢型射流阵列结构来处理大面积不规则表面。研究放电参数、电极结构及处理媒质等对射流阵列放电特性、耦合性和均匀稳定机制影响，确定稳定均匀放电运行条件和参数匹配；分析处理参数对表面特性及表面特性对沿面耐压性能影响，获得超憎水表面及沿面耐压性能最优的表面条件。通过多参数测量，建立放电参量、材料表面状态及表面绝缘状况三者间协同关联关系，给出射流阵列放电，及改性的有效调控方法，探索高活性等离子体产生机理及其提高沿面性能机制。项目对促进大气压等离子体应用，改善绝缘材料表面性能和优化电气设备绝缘结构有重要意义。

高压电气设备绝缘系统的性能受绝缘材料表面沿面闪络现象所限制，严重制约了电气设备及系统整体性能，提高绝缘表面憎水性可有效抑制电力系统中污闪、湿闪发生，目前采用的提高绝缘表面憎水性措施尚存在稳定性、均匀性差等缺点，探索改善绝缘表面憎水性新方法至关重要。本项目将含憎水性基团的大气压低温等离子应用到绝缘材料处理提高表面憎水性，进而提高其沿面耐压强度，采用射流阵列结构，来满足大面积和复杂形状材料处理要求，在He、Ar等气体和含F/Si等气氛中完成等离子体反应，引入疏水基团。通过研究电极排列方式、气体比例以及电源类型和参数等对射流阵列放电特性、耦合性和均匀稳定机制影响，确定产生大面积稳定均匀射流阵列放电的运行条件和参数匹配，提出射流阵列的产生机制和调控方法；通过研究射流等离子体增强绝缘表面憎水性效果，得到放电参数、电极结构及处理媒介比例对憎水性的变化规律，获取最优处理条件，提出控制憎水性改性的指导原则；结合表面憎水性、放电空间活性离子以及放电参量等关联分析，探讨射流阵列放电机制及其增强绝缘表面憎水性提高沿面耐压特性的机理。结果表明，等离子体射流阵列中同时存在电气和流场耦合，采用脉冲电源驱动和线性场阵列结构，并通过降低运行电压、增加气流和增加射流单元之间距离可以有效抑制射流耦合，提高阵列均匀性；憎水性成分添加能有效抑制电气耦合，有利于提高阵列均匀性，不同成分憎水性媒质添加时，获得最强憎水性粒子强度均存在最优比例；绝缘材料憎水性改性处理效果受处理时间和憎水性媒质含量影响，且存在最优值， PMMA、玻璃和环氧获得最优憎水性改性效果时，水接触角分别由65.2°、58.4°和46.3°提高到128°、122°和118°；射流阵列和绝缘表面作用后在表面的样貌改变作用和引入的含F和含Si憎水性基团，是其表面憎水性得到提高的主要原因。本项目研究对促进和拓展大气压低温等离子体研究及应用，改善和优化绝缘材料性能以及电气设备绝缘结构，保证电气设备安全运行具有重要价值。