VOLTAGE BALANCING CIRCUIT FOR MULTI-CELL MODULES

摘要

An energy storage module (100) includes a number of cells (120A, 120B) coupled in series between two end terminals (140, 150), and intermediate terminal (160) or terminals providing access to one or more junctions between individual cells of the module. Voltages of the module's cells are balanced by an intra-module voltage balancer. Two or more such modules are connected in series. To balance voltages of the modules, inter-module voltage balancers (324, 328, 332) are used. In one embodiment, an inter-module voltage balancer is connected to a junction of two modules and to intermediate terminals of the two modules. The inter-module balancer attempts to balance voltages of one or more cells of one of the two modules against one or more cells of the other module. Through operation of the intra-module balancers (130) of each module, voltages of both modules are balanced.