A method for controlling switching of an electrical system comprising having at least one frequency-controlled switch arm, includes the following steps: closing a first top or bottom switch, implementing a predetermined downtime and opening a second switch, for a period corresponding to the control frequency, and then: opening the first switch, comparing the voltage measured at the midpoint with a voltage threshold, determining a second instant t2 at which the voltage measured at the midpoint crosses the voltage threshold, closing the second switch at the second instant t2, calculating a downtime DT adjusted according to a formula which is a function of the control frequency Fsw, a first instant t1 and a second instant t2, the adjusted downtime being implemented as of the subsequent switching.