Patent ID: 9647463
Date: 2017-05-09
CPC Classifications: B60L,H01M,H02J,Y02E,Y02T

Claim:
1. At least one cell balancing module for voltage balancing of a plurality of stacks of energy storage cells, comprising: an interface to input a coded reference voltage derived from at least two reference voltages, wherein each cell balancing modules is arranged to locally generate a local reference voltage from the coded reference voltage input nodes for connecting at least one of the stacks of energy storage cells; a switching unit connected to each of the input nodes; and at least one local balancing unit which is coupled to the switching unit and to the interface and which is designed to compare the local reference voltage with cell voltages of the at least one of the stacks of energy storage cells to be connected, and designed to charge balance by charging or discharging the at least one of the stacks of energy storage cells to be connected depending on the comparison of the local reference voltage and the cell voltages, wherein the coded reference voltage is a digital representation of a reference voltage derived from a total system voltage of the plurality of stacks of energy storage cells, wherein the interface is a serial interface, and the coded reference voltage is simultaneously sent, as a digital representation, to the at least one local balancing unit via the serial interface, wherein a number of n cell balancing modules are inter-connected by way of a daisy chain via their respective interfaces, wherein local generation involves digital-to-analog conversion and the charge balance depends on an analog comparison between the local reference voltage and the cell voltages, and wherein each cell balancing module is arranged to acknowledge reception of the coded reference voltage by redundancy check.