The intermediate circuit is responsible for the intermediate storage of the energy. This happens either as a direct voltage (voltage intermediate circuit or U converter) or as a direct current (current intermediate circuit or I converter). A capacitance or an inductance can serve as a memory. These are dimensioned in such a way that the voltage Us for the U converter and the current Id for the I converter are greatly smoothed and can be viewed as constant quantities. This decouples the two converters to such an extent that they can be controlled independently of one another.