To address the zero-sequence circulating current issue caused by modular interleaved parallel connections in active front-ends of energy storage converters connected in parallel on both AC and DC sides
an improved circulating current suppression strategy based on a deadbeat algorithm is proposed. First
the effect of interleaved modulation among parallel modules on circulating current is analyzed. Second
a mathematical model of the system is established in the three-phase stationary coordinate system
along with an equivalent circuit of circulating current in the interleaved parallel system. Then
a circulating current controller is designed
where the control algorithm derives the zero-vector modulation parameters for each module by calculating the magnitude of the circulating current. Next
the zero vectors in the space vector pulse width modulation (SVPWM) process of the respective modules are adjusted to suppress the circulating current. Finally
experimental results verify that the proposed method can effectively suppress circulating current and achieve current sharing control