I designed the parameters of Cr1, Lr1, Cr2 and Lr2 from CLLLC_Calculation.xls，Fr1=Fr2=500khz，There is some slight deviation in the frequency value（±20Khz）
Only when Cr2 is removed, Series resonant frequency Fr is near to 500kHZ， When CR2 is introduced, the resonant frequency shifts to about 620khz.
why？
