The invention discloses an
energy storage system and a parallel operation control method thereof. The
system comprises a battery cluster, a battery
management system and an
energy storage converter. The battery
management system is respectively connected with the battery clusters and the
energy storage converter, and the plurality of battery clusters are connected with the energy storage converter through the
coupling circuit. Wherein a pre-charging
equalization loop is arranged between the battery cluster and the energy storage converter, and the battery
management system is used for controlling connection or disconnection of a circuit. The battery management
system is also provided with a threshold module which is integrated with a plurality of parallel operation thresholds and is used for judging the switching-on or switching-
off time of the
contactor. By constructing a
coupling system containing a pre-charging
equalization loop, the problems of
impact current and device damage caused by large inter-cluster
voltage difference in the parallel operation process of a traditional multi-
battery energy storage system are solved; and meanwhile, through a strategy of setting multiple parallel operation threshold values, targeted current balancing can be carried out according to different dynamic working conditions and
electric energy parameter differences, the
impact current is prevented from being too high, components are protected, and the operation stability of the system is improved.