- In this contribution, a highly dynamic calculation method of power quantities and additional electrical quantities, such as RMS values and fundamental waveforms, is presented. Typically, these quantities are calculated periodically based on the fundamental cycle of the electrical voltages and currents. Hence, they are well defined during steady state conditions for ideal periodical waveforms. During dynamic balancing processes, electrical signals are non-periodic. In a strict sense, the fundamental cycle-based definitions, which are well known from the literature, are not valid for these transient signals. However, this paper presents a novel definition for the calculation of cycle-based quantities based on the switching cycle of the inverter output voltages. This definition delivers instantaneous results during transient balancing processes, whereby it approximates the conventional fundamental cycle-based definitions during the steady state.