Patent ID: 8080898

Claim:
A power control method for secondary batteries constituting, in a grid connection system supplying electric power to a power system by combining a power generator whose output power fluctuates with a power storage compensator, the power storage compensator compensating for fluctuations of output power of the power generator; the method comprising the steps of: dividing the secondary batteries into a constant power control group and a demand responsive group, and distributing a predetermined constant input-output power out of power to be input and output provided to all the secondary batteries in order to compensate for the fluctuations of output power of the power generator to the constant power control group and the remaining input-output power to the demand responsive group to control input-output power of the secondary batteries respectively depending on the belonging groups, wherein the demand responsive group is further divided into a delay responsive group and an instant responsive group, input-output power subjected to a primary delay filter process out of the power to be input and output provided to the demand responsive group is distributed to the delay responsive group, and the remaining input-output power is distributed to the instant responsive group to control input-output power of the secondary batteries respectively depending on the belonging group, and wherein an upper limit of the input-output power of each secondary battery is provided, differences between a value of power to be input and output provided to each secondary battery and the upper limit are summed up to obtain a total deficient power, and the total deficient power is redistributed to each secondary battery.