In practice, consumption devices are not only resistive but also reactive and this reactance varies with time. Therefore, grid voltage is not stable and coefficients always change in spite of using Automatic Reactive Power Regulator. To regulate voltage and cosφ in an expected range, it is necessary to change the parameters of regulators as the loads change.
Determining regulated threshold and time of switching and changing parameters of regulators are controlled by microprocessor and power electronic components. Microprocessor provides a flexible energy control and a high automation ability to ensure a high reliability and stability of the system.
This paper presents how to determine the flexible regulated threshold to ensure the quality of supply energy..
