Seyfert galaxies are known to exhibit  significant X-ray variations,  as well as  
characteristic iron K and/or  L spectral features that  may be interpreted as broad 
emission lines or deep absorption edges.  We propose the Variable Double Partial 
Covering (VDPC) model to explain such energy spectra.

In this model,  observed flux/spectral variations below 10 keV within a ~day are primarily 
caused by change of the partial covering fraction of the central X-ray source by patchy 
absorbing clouds in the line-of-sight.  The transmitted spectral component through the 
absorbing clouds has  a characteristics spectral feature of  the ionized iron K-edge, 
which  is  the origin of the seemingly broad iron-line feature
commonly observed in Seyfert galaxies.  

Variation of the partial covering fraction of the constant X-ray luminosity source 
causes such an anti-correlation between the  direct (non-obscured) component and
the transmitted (obscured)  component, that cancels their variations each other.
The cancellation works most effectively at the energy band where intensities of the 
two components are  the closest to each other, namely,  just below the iron K-edge.  
This explains the significantly small fractional variations in the iron 
K-energy band,  another  well-known observational characteristic  of Seyfert galaxies. 
Also, occasionally, the fractional variation  peaks at the iron L-band,  where the flux 
separation between the direct component and the transmitted component is the widest
when a strong iron L-absorption line is observed.