The invention relates to a
system for charging at least one energy storing
cell (5) in a controllable energy store (2) that is used to control and supply
electric energy to an n-phase
electric machine (1), wherein n≧1. The controllable energy store (2) has n parallel
energy supply branches (3-1, 3-2, 3-3), each of which has at least two serially connected energy storing modules (4), each said energy storing module comprising at least one
electric energy storing
cell (5) with a corresponding controllable
coupling unit (6). The
energy supply branches (3-1, 3-2, 3-3) can be connected to a reference
bus (T-), and each
energy supply branch can be connected to a phase (U, V, W) of the
electric machine (1). The
coupling units (6) bridge the respective corresponding energy storing cells (5) or connect same into the respective energy supply
branch (3-1, 3-2, 3-3) dependent on control signals. The aim of the invention is to allow at least one energy storing
cell (5) to be charged. This is achieved in that each energy supply
branch (3-1, 3-2, 3-3) can be connected to and separated from a
secondary side (9-1′; 9-1″; 9-2′; 9-2″; 9-3′; 9-3″) of a charging
transformer (10′; 10-1″; 10-2″; 10-3″) by a respective controllable switching element (21-1; 21-2; 21-3), an additional charging
inductor (20-1; 20-2; 20-3) being arranged in each connecting line between the energy supply branches (3-1, 3-2, 3-3) and the secondary sides (9-1′; 9-1″; 9-2′; 9-2″; 9-3′; 9-3″) of the charging
transformer (10′; 10-1″; 10-2″; 10-3″).