Increasing development of power market has given rise to growing interest concerning the quality of the electric power.One of the important factors is voltage fluctuation and flicker.According with IEC61000-4-15

the paper concentrates on the calculation method of flicker emission

demonstrates the expression of voltage fluctuation and flicker

builds the simulink model of flicker

makes calculation program of short term flicker severity.The result indicates that the calculated relative error is small enough to fulfil the error condition.