Power converter and method for operating power converter

The invention relates to a method for operating a power converter (7) as an inverter between a DC voltage (U) and an AC voltage network (1), the power converter (7) having, for each AC voltage phase of the AC voltage network (1), at least one half-bridge (B1, B2, B3) connected to the AC voltage phase, the half-bridge having two semiconductor switches (SP1, SP2, SP3, SN1, SN2, each of the semiconductor switches (SP1, SP2, SP3, SN1, SN2, SN3) is connected in anti-parallel to the diodes (DP1, DP2, DP3, DN1, DN2, DN3). In the method, an activation angle interval (A12, A13, A23, A21, A31, A32, A1, A2) is determined for each semiconductor switch (SP1, SP2, SP3, SN1, SN2, SN3) within an angle period, the lower interval boundary of which is formed by subtracting the pre-firing angle (alpha) from the lower range boundary of the switching angle range (W12, W13, W23, W21, W31, W32, W1, W2), and the upper interval boundary of which is formed by subtracting the pre-firing angle (alpha) from the lower range boundary of the