The invention discloses an
energy storage system parallel operation circuit and a control method thereof. The
energy storage system parallel operation circuit comprises a master battery cluster loop, a slave battery cluster loop and a battery cluster pre-charging
equalization loop. And the pre-charging
equalization loop is provided with a controllable
resistor bypass which is connected in parallel with the
contactor and is controlled by the battery
management system. A charging and discharging parallel operation strategy is divided, the
voltage of a battery cluster is collected, a pre-charging
equalization loop is connected, and primary and secondary closing operations are carried out based on the
voltage state. The problem of circuit and device damage caused by
impact current due to large inter-cluster
voltage difference is solved through the master-slave configuration pre-charge equalization loop; meanwhile, the problem of long parallel
operation time caused by separation of a pre-charging
time sequence and an equalization
time sequence is solved by combining a control method; through the dynamic secondary closing operation, the problem that balance is easily damaged by
voltage fluctuation in the parallel operation process, and parallel operation fails is solved, parallel operation can be achieved without
system restart in a loop under a complex scene in cooperation with a
circuit architecture, and the parallel operation reliability, the operation stability and the charging efficiency of the
energy storage system are effectively improved.