Balanced control strategies for interconnected heterogeneous battery systems in smart grid applications

A battery network, comprising:

• a plurality of heterogeneous batteries coupled in parallel, the plurality of heterogeneous batteries coupled to an electric grid that includes at least one energy source and one energy load;
• a plurality of switches coupled to the plurality of heterogeneous batteries, each battery having a switch in series, the plurality of switches each controllable via application of a pulse-width modulation (PWM) frequency such that a duty cycle is defined as a proportion of on time for each switch;
• and
• a controller configured to:
• characterize each battery of the plurality of heterogeneous batteries based at least on an RC equivalent model to determine a time constant for each of the plurality of heterogeneous batteries;
• determine a respective duty cycle for each switch of the plurality of switches based on the characterization of the of the respective plurality of heterogeneous batteries;
• and
• apply the determined duty cycle to each of the respective plurality of switches such that a charge applied from the grid or a discharge to the grid converges to a balanced state-of-charge (SOC) for each of the plurality of heterogeneous batteries.