那位高手帮帮忙RCC问题

我做一款RCC 5W 6.5V输出的宽电压输入的电源,用EPC13,初级220T, 次级16T,辅助绕组18T L3.0mH,但现在他高压带满载时工作在间歇振荡的状态,间歇的频率落在了两点几K里,所以他有异音出来,我怎样让他脱离这种状态,而没有异音,请高手们帮帮忙.下面的是MOSFET的G极波形和原理图
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