Regenerative braking system for vehicle and method for operating regenerative braking system of vehicle

The invention relates to a regenerative braking system for a vehicle having a master brake cylinder (18); two brake circuits (10, 12), respectively having at least one first wheel brake cylinder (14a,14b), one second wheel brake cylinder (16a, 16b), one storage chamber (46a, 46b) and at least one valve (32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b); an electric motor; and a control device (50), which is designed to determine if a generative vehicle deceleration equal to a requested target vehicle deceleration (adriver) can be effected by means of a generative operation of the electric motor, or ifthis is delayed or interrupted for a time interval of at most two seconds, and, if necessary, to control at least the valves (32a, 32b, 34a, 34b, 36a, 36b, 38a, 38b) of the two brake circuits (10, 12)in such a way that at least a first hydraulic vehicle deceleration effected by means of the first wheel brake cylinders (14a, 14b) of the two brake circuits (10, 12) can be increased. The invention further relates to a method