Device and method for equalizing charges of series-connected energy stores
First Claim
Patent Images
1. A device for equalizing charges of series-connected individual cells of an energy storage device, comprising:
- an energy storage device including a plurality of individual series connected cells, the energy storage device having a positive terminal;
a DC/DC converter including an input and an output;
a switch having a switching state connecting said input of said DC/DC converter to the positive terminal of the energy storage device to remove energy from the energy storage device;
a DC/AC converter connected to said output of said DC/DC converter, said DC/AC converter including an intermediate circuit capacitor and a bridge circuit;
two AC bus lines connected to an output of said DC/AC converter; and
a coupling transformer and a rectifier connected between one or two adjacent cells of the series connected individual cells and said AC bus lines, said coupling transformer having only one or two secondary windings regardless of a number of capacitors.
2 Assignments
0 Petitions
Accused Products
Abstract
A device and method for equalizing the charges of series-connected individual cells of an energy storage device with a DC/DC converter, which draws energy from the energy storage device or from another energy source, charges an intermediate circuit capacitor whose voltage is inverted in a DC/AC converter, converts the alternating voltage via AC bus lines and coupling transformers by way of a rectifier into a pulsating direct current, and charges the cell having the lowest cell voltage with the pulsating direct current.
27 Citations
17 Claims
-
1. A device for equalizing charges of series-connected individual cells of an energy storage device, comprising:
-
an energy storage device including a plurality of individual series connected cells, the energy storage device having a positive terminal; a DC/DC converter including an input and an output; a switch having a switching state connecting said input of said DC/DC converter to the positive terminal of the energy storage device to remove energy from the energy storage device; a DC/AC converter connected to said output of said DC/DC converter, said DC/AC converter including an intermediate circuit capacitor and a bridge circuit; two AC bus lines connected to an output of said DC/AC converter; and a coupling transformer and a rectifier connected between one or two adjacent cells of the series connected individual cells and said AC bus lines, said coupling transformer having only one or two secondary windings regardless of a number of capacitors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method of equalizing charges of series-connected individual cells of an energy storage device, the method which comprises:
providing a device for equalizing charges of series-connected individual cells of an energy storage device, comprising; an energy storage device including a plurality of individual series connected cells, the energy storage device having a positive terminal, a DC/DC converter including an input and an output, a switch having a switching state connecting the input of the DC/DC converter to the positive terminal of the energy storage device to remove energy from the energy storage device, a DC/AC converter connected to the output of the DC/DC converter, the DC/AC converter including an intermediate circuit capacitor and a bridge circuit, two AC bus lines connected to an output of the DC/AC converter, and a coupling transformer and a rectifier connected between one or two adjacent cells of the series connected individual cells and the AC bus lines, the coupling transformer having only one or two secondary windings regardless of a number of capacitors; conducting, from the DC/DC converter fed by the energy storage device or a further energy source, a current to the intermediate circuit capacitor and thereby building a voltage at the converter for charging the cells; inverting the voltage with the DC/AC converter and transmitting over the AC bus lines to the secondary side of the coupling transformer; converting the secondary alternating current by way of the diodes or the rectifier into a rectified, pulsing charge current for the cell with a lowest cell voltage, as soon as the voltage reaches a value corresponding to a sum of the cell voltage of the cell with the lowest voltage and one or two diode forward voltages. - View Dependent Claims (13, 14, 15, 16, 17)
Specification