Patent ID: 8653799

Claim:
An operating method for a multilevel converter which has a number of converter phases which are connected to the phases of a three-phase network in a star or delta connection, comprising: determining an active component and at least two asymmetrical components on the basis of phase voltage values and phase current values, wherein the phase voltage values are characteristic of the phase voltages present at the phases and the phase current values are characteristic of the phase currents flowing in the phases, wherein the active component is characteristic of the total active current flowing in the three-phase network and the at least two asymmetrical components are characteristic of a distribution, among the phases, of the total active and reactive currents flowing, filtering the active component and the at least two asymmetrical components with one filter characteristic each, multiplying each of the phase voltage values by the filtered active component and the at least two filtered asymmetrical components, multiplying the multiplied phase voltage values by a respective weighting factor and then adding them to the phase current values, determining a zero current on the basis of the asymmetrical components and the phase voltage values and adding the zero current to the phase current values, wherein the zero current is determined in such a way that it symmetrizes any asymmetrical active power flux of the multilevel converter which would occur without the zero current, and determining an actuation state for the converter phases on the basis of the phase current values which are modified in such a way, and actuating the converter phases in accordance with the determined actuation state.