Arrangement for controlling a converter (9, 15) of a power generation system, in particular a wind turbine, the converter being connected to a connection point to a utility grid, the arrangement comprising: a measurement section adapted to provide measurement values indicative of values of current and voltage at the connection point; a main converter controller adapted to receive the measurement values (33, 35) and to generate a main converter control signal based on the measurement values; an active filter system adapted to receive the measurement values (33, 35) and to generate an active filter control signal based on the measurement values; an addition element adapted to add the main converter control signal and the active filter control signal and to supply the sum signal as a control signal to the converter (9, 15), wherein the active filter system comprises plural active filter portions (43_1, 43_2) for plural considered center frequencies (ω1, ω2) each configured to output a, in particular transformed, frequency specific active filter control signal (61_1, 61_2), wherein the frequency specific active filter control signals are added to result in the, in particular transformed, active filter control signal, wherein at least one, in particular each, active filter portion (43_1, 43_2) is characterized by: a center frequency (ω1, ω2); a desired resistance (R1, R2); and a desired reactance (X1, X2), and being configured to output a, in particular transformed, center frequency specific voltage signal configured to achieve an impedance of the converter at the center frequency defined by the desired resistance and the desired reactance, wherein at least one, in particular each, active filter portion (43_1, 43_2) comprises: a multiplication element (51_1, 51_2) adapted to multiply the transformed value of the current with a complex number (R1 + jX1, R2 + jX2) representing the desired resistance and the desired reactance; an addition element (53_1, 53_2) adapted to derive a voltage error (55_1, 55_2) of the complex number multiplied transformed value (52_1, 52_2) of the current and the transformed value of the voltage; a complex resonator (59_1, 59_2) tuned at the particular center frequency (ω1, ω2) adapted to receive the voltage error and output the, in particular transformed, center frequency specific voltage signal (61_1, 61_2). a measurement section adapted to provide measurement values indicative of values of current and voltage at the connection point; a main converter controller adapted to receive the measurement values (33, 35) and to generate a main converter control signal based on the measurement values; an active filter system adapted to receive the measurement values (33, 35) and to generate an active filter control signal based on the measurement values; an addition element adapted to add the main converter control signal and the active filter control signal and to supply the sum signal as a control signal to the converter (9, 15), wherein the active filter system comprises plural active filter portions (43_1, 43_2) for plural considered center frequencies (ω1, ω2) each configured to output a, in particular transformed, frequency specific active filter control signal (61_1, 61_2), wherein the frequency specific active filter control signals are added to result in the, in particular transformed, active filter control signal, wherein at least one, in particular each, active filter portion (43_1, 43_2) is characterized by: a center frequency (ω1, ω2); a desired resistance (R1, R2); and a desired reactance (X1, X2), a center frequency (ω1, ω2); a desired resistance (R1, R2); and a desired reactance (X1, X2), and being configured to output a, in particular transformed, center frequency specific voltage signal configured to achieve an impedance of the converter at the center frequency defined by the desired resistance and the desired reactance, wherein at least one, in particular each, active filter portion (43_1, 43_2) comprises: a multiplication element (51_1, 51_2) adapted to multiply the transformed value of the current with a complex number (R1 + jX1, R2 + jX2) representing the desired resistance and the desired reactance; an addition element (53_1, 53_2) adapted to derive a voltage error (55_1, 55_2) of the complex number multiplied transformed value (52_1, 52_2) of the current and the transformed value of the voltage; a complex resonator (59_1, 59_2) tuned at the particular center frequency (ω1, ω2) adapted to receive the voltage error and output the, in particular transformed, center frequency specific voltage signal (61_1, 61_2). a multiplication element (51_1, 51_2) adapted to multiply the transformed value of the current with a complex number (R1 + jX1, R2 + jX2) representing the desired resistance and the desired reactance; an addition element (53_1, 53_2) adapted to derive a voltage error (55_1, 55_2) of the complex number multiplied transformed value (52_1, 52_2) of the current and the transformed value of the voltage; a complex resonator (59_1, 59_2) tuned at the particular center frequency (ω1, ω2) adapted to receive the voltage error and output the, in particular transformed, center frequency specific voltage signal (61_1, 61_2).