A method for setting a desired output
voltage of a power supply
branch of a controllable energy store, for controlling and supplying electrical energy to an n-phase
electric motor, where n≧1. The controllable energy store has n parallel power supply branches, which each have at least two serially connected
energy storage modules including at least one
electrical energy storage cell having an assigned, controllable
coupling unit; are connected to a reference
bus on one side; and are connected to phases, respectively, of the
electric motor on the other side. At least one
coupling unit is controlled by pulses so that the arithmetic mean of the output
voltage of a power supply
branch corresponds to the desired output
voltage. The
energy storage cells respectively assigned to the
coupling unit are switched into the respective power supply
branch for a
pulse duration, and are bypassed during a pause time.