Bypass control structure of link unit of chain circuit active power filter and method

摘要

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.

主权项

1. A bypass control structure of a link unit of a chain circuit active power filter, comprising a main controller (1), a chain circuit multilevel inverter (2) for generating a compensation voltage and controlling a link unit bypass thereof, and a reactor (3) for generating a compensation current and which is connected to an external electric network; wherein the chain circuit multilevel inverter (2) comprises two or more levels of link units (21); the link units (21) each have a unit controller (211), a fault detect circuit (212), a single-phase full-bridge inverter (213), a DC/DC power supply (214) and a DC coupling circuit (215); the unit controller (211) is connected to the main controller (1), the fault detect circuit (212) and the single-phase full-bridge inverter (213); an input end of the DC coupling circuit (215) is electrically connected to two DC voltage sides of the link unit (21) in which the DC coupling circuit (215) is located, and is connected to two DC voltage sides of an adjacent link unit (21); an input end of the DC/DC power supply (214) is electrically connected to an output end of the DC coupling circuit (215), and an output end of the DC/DC power supply (214) is electrically connected to the unit controller (211) for supplying power for each components.