CONTROL METHOD FOR AUTOMATIC CAPACITIVE COMPENSATOR MEANT TO ENHANCE POWER FACTOR AND BALANCE LOAD IN FOUR-WIRE THREE-PHASED ELECTRIC SYSTEMS

摘要

The invention relates to a control method for an automatic capacitive compensator meant to enhance the power factor and to balance load in four-wire three-phase electric systems, implemented by means of a computer program in the compensator control system. According to the invention, the method consists in that: it defines, as input quantities of the adjustment process, the effective values of the real and imaginary components of load sequence currents, defines, as control quantities of the adjustment process, the compensation levels of the components of positive, negative and zero sequence of load currents, defines, as output quantities of the adjustment process, the values of the six susceptances of the compensator, computed with analytical relations that establish the direct relation with the input quantities, uses a sequence of operation steps in the adjustment process with a view to obtaining negative or null values for the output quantities, by iterative correction of control quantities, it achieves the adjustment of the compensator susceptances so that an optimal distribution of the capacitive reactive power of compensation between the two compensator functions is obtained, namely the enhancement of the power factor and the balance function, and it also achieves the optimal distribution of the capacitive reactive power of compensation on the positive sequence between the two three-phased circuits of the compensator, from the condition of minimization of the number and value of the susceptances to be cancelled because they cannot be brought in the capacitive range.