A peak current limit control technique in low-voltage ride through operation of the star-connected cascaded H-bridges converter

Abstract

As smart grid techniques grows quickly and complexly, the Static synchronous Compensator (STATCOM) has become one of the most important role to manage the power flow and regulate the grid voltage. As grid voltage faults occur, the STATCOM becomes more crucial to increase the system stability. This paper present the STATCOM application by the modular multilevel cascaded converter (MMCC) based on single start bridge cell (SSBC) for the medium-voltage level to VAR compensation. In low-voltage ride-through (LVRT) operation, this paper proposes the peak current limit control (PCLC) to meet the grid requirement and utilize the converter's current capacity. Moreover, this paper also presents a average power balancing control by zero-sequence voltage injection to balance converter's voltages and without affects the converter's output current.