Abstract: The present application relates to a bypass control structure of a link unit of a chain circuit active power filter and a control method thereof. The bypass control structure includes a main controller, a chain circuit multilevel inverter and a reactor connected to an external electric network. The chain circuit multilevel inverter generally comprises multiple levels of link units. A state of the switch means in each link unit in a chain circuit active power filer is detected in real time, and types of detected faults are classified so as to bypass the fault of the link unit with fault by utilizing the control of the switch means without fault in the link unit with fault. Normal operating, stability, reliability, high efficiency of the active power filter are ensured. Therefore, the problem that the operation must be suspended until the fault is eliminated is solved without any additional bypass means.

Abstract: The present application relates to a bypass control structure of a link unit of a chain circuit active power filter and a control method thereof. The bypass control structure includes a main controller, a chain circuit multilevel inverter and a reactor connected to an external electric network. The chain circuit multilevel inverter generally comprises multiple levels of link units. A state of the switch means in each link unit in a chain circuit active power filer is detected in real time, and types of detected faults are classified so as to bypass the fault of the link unit with fault by utilizing the control of the switch means without fault in the link unit with fault. Normal operating, stability, reliability, high efficiency of the active power filter are ensured. Therefore, the problem that the operation must be suspended until the fault is eliminated is solved without any additional bypass means.