Patent ID: 7518893

Claim:
A method for operation of a converter circuit, in which the converter circuit has a converter unit with a multiplicity of drivable power semiconductor switches and an LCL filter which is connected to each phase connection of the converter unit, in which the drivable power semiconductor switches are driven by means of a drive signal (S) which is formed from reference voltages (u* 1 , u* 2 , u* 3 ), wherein the reference voltages (u* 1 , u* 2 , u* 3 ) are formed by subtraction of damping voltages (u d1 , u d2 , u d3 ) from reference-phase connection voltages (u* i1 , u* i2 , u* i3 ), with the damping voltages (u d1 , u d2 , u d3 ) being formed from filter capacitance currents (i Cf1 , i Cf2 , i Cf3 ), weighted with a variable damping factor (K f ) of the LCL filter, and wherein the filter capacitance currents (i Cf1 , i Cf2 , i Cf3 ) are filtered by means of a high-pass filter, wherein the reference-phase connection voltages (u* i1 , u* i2 , u* i3 ) are formed from a d-component of the Park-Clarke transformation (produced by regulation of a dc voltage (u dc ) of a capacitive energy store which is connected to the converter unit (1) at a dc voltage reference value (u* dc ) of reference-phase connection currents (i* fid ) and from a predeterminable q-component of the Park-Clarke transformation of the reference-phase connection currents (i* fiq ).