Study of Corona Discharge Treaters consisting of Voltage-Source Inverter Fed Series Resonant Circuits using IGBT's

在过去的5-10年里，功率晶体管、静电感应晶体管、功率MOSFET等快速开关器件的发展取得了显著的进展。值得注意的是，绝缘栅双极晶体管(IGBT)适用于频率范围为20-60kHz的高频逆变器。高频高压电源对于电晕放电处理是必不可少的。电晕放电处理薄膜的目的是使其与油墨、胶水和涂料具有亲和力。本文提出了一种新型的电晕放电电源逆变系统，该系统由一个50 kHz5kW的IGBT电压型逆变器和一个匝比为1：20的升压变压器组成。升压变压器的漏感和升压变压器的杂散电容构成串联谐振电路，不需要任何外接电感和电容。串联谐振电路被认为是输出电压为250V的逆变器与输入电压为20KV的逆变器之间的匹配电路。这对维持适当的电晕放电起着重要作用。取得了以下研究成果：1.采用三相二极管整流器作为交直流功率转换器。这导致了一个简单的电源电路。虽然输出功率的控制是通过功率因数控制来实现的，但是在无损缓冲电路的帮助下，逆变器的效率达到了96%。在控制电路中引入了本研究开发的新型锁相环电路，实现了正确的电晕放电。

Over the last 5-10 years, remarkable progress has been made in the development of fast switching devices such as power transistors, static induction transistors, power MOSFET's, and so on. Notably, attention is paid to Insulated Gate Bipolar Transistors (IGBT's) which are suitable for high-frequency-inverters with the frequency range of 20-60kHz.A high-frequency high-voltage power supply is essential for corona discharge treatment. The object of corona discharge treatment for film is to render the affinity to inks, glues and coatings. So far, vacuum tubes have been used for such a power supply at the expense of efficiency and feliability.In this study, a new inverter system for a corona discharge treater is developed, which consists of a 50kHz 5kW voltage-source inverter using IGBT's and a step-up transformer of turn ratio 1:20. A leakage inductor of the step-up transformer plus a stray capacitor of the step-up transformer and the corona discharge treater forms a series resonant circuit without any externally connected inductor or capacitor. The series resonant circuit is considered a matching circuit between the inverter of output voltage 250V and the treater of input voltage 20KV. This plays an important role in maintaining proper corona discharge. The following results are obtained :1. A three-phase diode rectifier is used as an ac to dc power converter. This results in a simple power circuit.2. Although output power control is achieved by power factor control, the inverter efficiency is 96% with the help of lossless snubbing circuits.3. A new PLL circuit developed in this study is introduced to the control circuit, leading to proper corona discharge.