[论文解读] Method of Controlling Corona Effects and Breakdown Voltage of Small Air Gaps Stressed by Impulse Voltages

Αθανάσιος Μαγλάρας, Triphon G. Kousiouris+4 more|arXiv (Cornell University)|Oct 15, 2014

Aerosol Filtration and Electrostatic Precipitation参考文献 8被引用 5

一句话总结

本文提出了一种新方法，通过在回路中串联电阻来控制小空气间隙在冲击电压作用下的电晕效应和击穿电压。该电阻可延长充电时间并降低峰值电压，显著抑制局部放电并提升绝缘配合性能。实验与仿真结果验证了该方法在不同间隙几何形状、极性和接地配置下的有效性。

ABSTRACT

This paper investigates the influence of a resistor on the dielectric behavior of an air gap. The resistor is connected in series with the air gap and the latter is stressed by impulse voltage. Air gap arrangements of different geometry with either the rod or the plate grounded are stressed with impulse voltages of both positive and negative polarity. The resistor is connected in series with the air gap in the return circuit connecting the gap with the impulse generator. The method followed involves the investigation of the graphs of the charging time concerning the air gaps capacitances, in connection to the value of the resistor, the geometry of the gap, the effect of grounding and the polarity effect. It is determined that the charging time of the air gap increases, as the value of the resistor increases. It is also determined that the peak voltage value of the fully charged air gap decreases as the value of the resistor increases. The results of the mathematical and simulation analysis are compared with the results of the oscillograms taken from experimental work. In addition and consequently to the above results it is concluded from the experimental work that the in series connection of the resistor in the circuit has significant influence on corona pulses (partial discharges) occurring in the gap and on the breakdown voltage of the gap. A new method of controlling the corona effects and consequently the breakdown voltage of small air gaps stressed by impulse voltage of short duration in connection to the ground effect and the polarity effect has arisen. Furthermore through mathematical analysis of the charging graphs obtained from simulation and experimental oscillograms there was a calculation of the values of the capacitance of the air gaps in relation to their geometry and the results were compared to the values calculated with mathematical analysis.

研究动机与目标

• 研究串联电阻对小空气间隙在冲击电压应力下介电行为的影响。
• 分析电阻值、间隙几何形状、极性和接地方式对充电时间和峰值电压的影响。
• 提出一种控制冲击电压下空气间隙电晕脉冲与击穿电压的方法。
• 通过仿真、实验示波波形与电容数学建模的对比，验证所提方法。
• 利用理论与实测数据量化空气间隙几何形状与电容之间的关系。

提出的方法

• 在空气间隙与冲击电压发生器之间的回路中串联接入电阻，以控制充电动态特性。
• 对棒-板和棒-棒空气间隙施加正负极性冲击电压，间隙几何形状各异。
• 从实验中获取的示波波形测量充电时间与峰值电压，并与仿真结果进行比较。
• 基于RC时间常数的数学分析，从充电曲线计算空气间隙的电容。
• 根据几何参数推导理论电容值，并与实验值和仿真值进行比较。
• 系统评估接地配置与极性对电晕起始与击穿的影响。

实验结果

研究问题

• RQ1 串联电阻值如何影响小空气间隙在冲击电压下的充电时间？
• RQ2 电阻对间隙在冲击应力下所达到的峰值电压有何影响？
• RQ3 电阻如何影响间隙中电晕脉冲（局部放电）的发生与强度？
• RQ4 间隙几何形状、极性和接地配置如何与电阻共同作用，影响击穿电压？
• RQ5 仿真与实验的充电曲线在多大程度上与理论电容计算结果一致？

主要发现

• 增大串联电阻值可延长空气间隙的充电时间，二者呈现直接正比关系。
• 电阻值越高，间隙所达到的峰值电压越低，从而降低应力水平。
• 电阻显著抑制电晕脉冲与局部放电，改善绝缘配合性能。
• 由于电压应力降低与电压上升延迟，击穿电压随电阻值增大而提高。
• 从示波波形测得的电容值与基于间隙几何形状和RC时间常数的理论计算值高度吻合。
• 该方法在不同极性、接地类型与间隙配置下，均能有效控制电晕效应与击穿电压。