METHOD FOR OPERATING A CONVERTER CIRCUIT AND DEVICE FOR CARRYING OUT THE METHOD

摘要

The invention relates to a method for operating a converter circuit. To this end, the converter circuit comprises a converter unit (1) with a multitude of controllable power semiconductor switches and an energy store circuit (2) formed by two series-connected capacitors. The controllable power semiconductor switches are controlled by means of a control signal (S) formed from a hysteresis signal vector (x) and the hysteresis signal vector (x) is formed from a differential phase connection current vector (?i_fi,i) by means of a hysteresis controller (6), and the differential phase connection current vector (?i_fi,i) is formed by subtracting a phase connection current vector (i_fi,i) from a reference phase connection current vector (i_fi,i,ref), and the reference phase connection current vector (i_fi,i,ref) is formed from a differential output value (P_diff), a differential reactive power value (Q_diff) and of a phase flow vector (?_g,aß). In order to keep the switching frequency of the controllable power semiconductor switches as constant as possible, a current correction value (i_o) is additionally subtracted for forming the differential phase connection current vector (?i_fi,i), the current correction value (i_o) being formed by integrating a phase connection voltage mean value (U_inv,A), and the phase connection voltage mean value (U_inv,A) is formed by determining the arithmetic mean of the phase connection voltages (U_inv,iM) with a reference point of the connection point (M) of the capacitors of the energy store circuit (2). The invention also relates to a device with which the method can be carried out in a particularly simple manner.