This paper presents the Taylor series expression based equivalent circuit models of light emitting diodes (LEDs) for the analysis of the LED driver system. In order to describe the non-linear V-I characteristics of LEDs, Taylor series can be used to express the equivalent conductance components in the DC and AC equivalent circuit models of LEDs. Based on the Taylor series expression, the equivalent AC conductance in the equivalent circuit model of the LED array can be derived. Finally, one LED array with 5 paralleled strings of 4 LEDs in series is used for the comparison of the theoretical and measured results of the equivalent AC conductance component in the corresponding equivalent circuit model.