System for charging an energy store, and method for operating the charging system

摘要

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 a neutral point (S) of the electric machine (1) and the reference bus (T-) can be connected to a secondary side (9) of a charging transformer (10).

主权项

1. A system for charging at least one energy storage cell in a controllable energy store which is used to control and supply electrical energy to an electrical machine having a defined number of phases, where the defined number is greater than or equal to one, wherein
the controllable energy store has a number of parallel energy supply branches, wherein the number of parallel energy supply branches is equal to the defined number of phases, which
have in each case at least two energy storage modules, which are connected in series and comprise in each case at least one electrical energy storage cell having an associated controllable coupling unit,are switchably connected on one side to a reference rail andare switchably connected on the other side to in each case one phase of the electrical machine, the coupling units are configured as full bridges and, depending on control signals, bypass the respectively associated energy storage cells or connect the respectively associated energy storage cells into the respective energy supply branch, and the coupling units further configured to
in a current increase stage in the energy supply branches, set a voltage which is smaller in terms of magnitude than that at the secondary side of the charging transformer based on the control signals, andin a current reduction stage following the current increase stage in the energy supply branches, set a voltage which is greater in terms of magnitude than that at the secondary side of the charging transformer based on the control signals, and a star point of the electrical machine connected to each of the parallel energy supply branches and the reference rail connected to a secondary side of a charging transformer.