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

在过去的5-10年中，快速开关器件如功率晶体管、静电感应晶体管、功率MOSFET等的发展取得了显著的进步。介绍了一种适用于20 - 60 kHz高频逆变器的绝缘栅双极晶体管（IGBT），并介绍了一种高频高频逆变器的设计方法。电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、胶粘剂和涂料具有亲和性。本课题研制了一种新型电晕放电电源系统，它由一个50 kHz、5 kW的IGBT电压源逆变器和一个匝数比为1：20的升压Transformer组成。升压Transformer的漏感器加上升压Transformer的杂散电容器与电晕放电处理器构成串联谐振电路，不需要外接电感器或电容器。串联谐振电路被认为是输出电压为250 V的逆变器和输入电压为20 KV的处理器之间的匹配电路。这在维持适当的电晕放电中起着重要作用。得到了以下结果：1.三相二极管整流器用作交流到直流功率转换器。这导致一个简单的电源电路。2.虽然输出功率控制是通过功率因数控制来实现的，但在无损缓冲电路的帮助下，逆变器的效率达到96%.本研究中开发的一种新的锁相环电路被引入到控制电路中，导致适当的电晕放电。

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.