Comments on "Prediction of Subharmonic Oscillation in Switching   Converters Under Different Control Strategies"
  A recent paper [1] (El Aroudi, 2012) misapplied a critical condition (Fang and Abed, 2001) to a well-known example. Even if the mistake is corrected, the results in [1] are applicable only to buck converters and period-doubling bifurcation. Actually, these results are known in Fang's works a decade ago which have broader critical conditions applicable to other converters and bifurcations. The flaws in [1] are identified. 
Chung-Chieh Fang
cs.SY math.DS nlin.CD