DBD型臭氧发生器M型“缺口”现象的探讨

Discuss on the M "Gap" Shape Phenomenon of DBD-Type Ozone Generator

介质阻挡放电(Dielectnic Bannien Dischange,简称DBD)型臭氧发生器用高频逆变电源,在变压器初级观测到电压出现两次翻转过程,呈M形状,这里定义为电压M型"缺口"。通过电压电流数据的采集对比,发现由于电流换向时间与IGBT导通时间不一致,导致容性负载通过变压器及IGBT体二极管向电源放电,使得变压器初级电压发生短暂时间的翻转,开关管管压降出现M形状的"缺口"。分析可知在电压翻转的两个瞬间,介质电容对变压器存在较大的过电压冲击,影响变压器的绝缘特性及系统的可靠性。并进一步讨论了M型"缺口"区间大小在正负半周期对介质阻挡放电的影响。在实际调试过程中通过调节PWM触发脉冲的占空比及缩短桥式逆变电路中IGBT桥臂的"死区"时间,避免M型"缺口"的出现。

In the high frequency inverter power supply for DBD-type ozone generator,voltage turned twice can be ob-served at low tension side of transformer,emerging M shape,and it＇s called M ＂gap＂ in this text.By collecting the voltage and current,it is found that because the asynchronism between the current reversal time and the breakover time of IGBT,capacitve load discharge to power supply by transformer and IGBT＇s diode,it leads to the short-time turning of voltage at transformer＇s low tension side,and emerges M ＂gap＂ on the voltage of the switch.It analyses that barium titanal capacitor exists overvoltage to transformer on the two voltage-turning time,and it effects to the di-electric properties of transformer and the reliability of system.It also discuss the effect between the time of M ＂gap＂ and the dielectic barrier discharge in all period.The M ＂gap＂ can be avoided through accommodating the duty rate of PWM or shortening IGBT＇s ＂Deadtime＂ of the inverter at the actual debugging.