求教升降压式PFC

话题:升降压式PFC讨论我想做一个PFC,但是要求输出电压可以升压也可以降压.所以我选择了buck-boost PFC电路,用的芯片是IR1150,拓扑如图1,但是buck阶段的电流波形非常差,PF值很低.波形如图2,请大家帮助分析原因
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