The present application belongs to the technical field of
energy storage system, and particularly relates to an
energy storage system and a
negative sequence current phase-to-phase SOC
equalization control device and method. The
energy storage system of the present application is a high-
voltage energy storage system. First, the three-phase SOC deviation values of the energy storage system are compared to determine the
maximum deviation. When the absolute value of the deviation value of the
maximum deviation is less than or equal to a set dead zone value, the
negative sequence current given value is set to 0. When the absolute value of the deviation value of the
maximum deviation is greater than the set dead zone value, the
initial phase of the corresponding
negative sequence current is set according to different conditions of the three-phase SOC deviation. Then, the d-axis and q-axis component given values of the negative sequence current are obtained according to the
initial phase and the set current ratio. The negative
sequence control component is obtained through d-axis and q-axis decoupling control, and is added to the obtained positive
sequence control component to obtain the modulation wave of the converter in the energy storage system, so as to realize phase-to-phase SOC
equalization. This scheme solves the problem of phase-to-phase SOC
equalization control of the negative sequence current of the energy storage system through a
software strategy with small calculation amount and clear logic.