我用的ucc28019做的PFC,用三根电热丝做负载,一开机电压能稳定在430V,但是一分钟后电压就下降到360V,然后一直稳定在350~360之间,请问是什么原因啊?
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我用的ucc28019做的PFC,用三根电热丝做负载,一开机电压能稳定在430V,但是一分钟后电压就下降到360V,然后一直稳定在350~360之间,请问是什么原因啊?
是过流造成的,减小电流sense电阻即可解决,可以通过测试sense电压来确认。
建议您确认电驴丝的峰值功率,然后按照datasheet或者设计指导重新确认电感等相关参数,因为电感也会影响到sense电阻的电流。