无源软开关boost电路疑问

最近研究无源软开关,在matlab下面仿真,但是出的波形和理论的不大一样.不知道为什么.我的电路取值L=1mH,snubber L=50uH.Cs=15nF,Cr=500nF.工作频率50Khz.
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理论波形是这样的
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不知道为什么我的经过开关管的电路无法到0.是开关频率过快?
Cs,Cr的波形也有些怪.经过SNUBBER L的电流也没有到0.
请问大家知道为什么吗?