Regulator measures active power waveform on the base of number of pulses from energy meter outputs and conversion constant [Wh/pulse] which is set. These measurements are being done within the frame of measuring period, and compared with waveform defined by regulation curve, with set hysteresis included. On the base of comparison result ,regulator will decide, if it is necessary to disconnect some stage ,or on the contrary, that is possible to connect some. Defined parameters of particular stages have to be taken into account.