Control method and control device for battery system and battery system

A control method for a battery system, wherein the battery system comprises N battery clusters connected in parallel, each of the battery clusters has a DCDC converter connected in series therewith, and the method comprises:

• determining that a state of charge (SOC) and a current of a first battery cluster in the N battery clusters meet a first preset condition, the first preset condition comprising:
• the SOC of the first battery cluster is greater than a first threshold and the current of the first battery cluster is greater than a second threshold or less than a third threshold;
• or, the SOC of the first battery cluster is less than a fourth threshold and the current of the first battery cluster is greater than the second threshold or less than the third threshold, wherein the second threshold is set according to a maximum permissible current of the first battery cluster, and the third threshold is set according to an average current of the N battery clusters;
• and
• sending first information to a first DCDC converter connected in series with the first battery cluster, the first information being used to instruct controlling the current of the first battery cluster to reach a first preset current.