High voltage-type redox flow battery comprising SOC balancing device

A high voltage-type redox flow battery including an SOC balancing device comprising a plurality of serially connected modules (1001, 1002, 1003, . . . , 100n);

• a battery management system (BMS) monitoring a state of charge (SOC) of the plurality of modules (1001, 1002, 1003, . . . , 100n);
• and
• a plurality of DC/DC converters (2001, 2002, 2003, . . . , 200n) connected in parallel with each of the plurality of modules,
• wherein each (1001) of the plurality of modules includes a stack (10), a catholyte tank (30a), a catholyte pump (20a) for providing a catholyte of the catholyte tank (30a) to the stack (10), a catholyte inlet pipe (21a) connecting the catholyte pump (20a) and the stack (10), a catholyte outlet pipe (11a) connecting the stack (10) and the catholyte tank (30a), a catholyte tank outlet pipe (31a) connecting the catholyte tank (30a) and the catholyte pump (20a), an anolyte tank (30b), an anolyte pump (20b) for providing an anolyte of the anolyte tank (30b) to the stack (10), an anolyte inlet pipe (21b) connecting the anolyte pump (20b) and the stack (10), an anolyte outlet pipe (11b) connecting the stack (10) and the anolyte tank (30b), and an anolyte tank outlet pipe (31b) connecting the anolyte tank (30b) and the anolyte pump (20b), wherein total number of the plurality of modules must meet following 1) and 2) conditions
• 1) The lowest voltage of the stack (10)×(total number of modules−1)>the lowest convertible voltage of a preset PCS (Power Control System),
• 2) The highest voltage of the stack (10)×the total number of the total modules<the maximum convertible voltage of the preset PCS,
• wherein the plurality of modules (1001, 1002, 1003, . . . , 100n) are manually or automatically connected to bypass circuits (1091, 1092, . . . 109n) so that in case that a module has a problem, only the other of the plurality of modules without the problematic module can be connected in series,
• wherein output terminals of the plurality of DC/DC converters (2001, 2002, 2003, . . . , 200n,) are connected to a common busbar (300), and
• wherein the battery management system (BMS) monitors the SOC of each module in real time during charging and discharging, and a current applied to each module is to satisfy the following equations
• In=I+I×dIn
• (In:
• a current applied to the nth module, I:
• a system current, dIn:
• an added or subtracted current)
• Charging:
• dIn=(SOCavg−SOCn)/SOCavg (SOCavg:
• average SOC of available modules, SOCn:
• SOC of nth module)
• Discharging:
• dIn=(SOCn−SOCavg)/SOCavg (SOCavg:
• average SOC of available modules, SOCn:
• SOC of nth module).