Relationship between the Flicker Criteria ΔV10 and Pst

The short-term and the long-term value P_st and P_lt are the common-used quantities for the characterization of flicker severity. But in some areas of Asia (Japan, Taiwan) power companies use another criterion for the flicker assessment - the voltage flicker index ΔV₁₀ which characterizes the actual flicker with respect to an equivalent value of the voltage modulation component with the frequency of 10 Hz. It results that the same voltage fluctuation can be permissible according to one flicker criterion and non-permissible according to other flicker criterion. This requires double costs of flicker level verification, for example, for the new installations designed in the countries one flicker criterion and in the utilities other one is used. There are a lot of attempts to find a simple and reliable approach for the conversion from one index to the other one by multiplying the indices with a factor, but no universal method was developed. In the paper based on analytical calculations and on-site measurement results the ratio between both flicker assessment criteria is shown to be dependent on the signal parameters.