Research on control strategy of distributed power flow controller under low current condition

Distributed Power Flow Controller (DPFC) is a typical D-FACTS device for power flow control by distributed installation, which is installed on overhead transmission lines or substations. The voltage source converter (VSC) unit in DPFC is connected in series to the transmission line, which can adjust the line impedance continuously and quickly. DPFC obtains energy mainly through the AC line current. When the line current is too low, DPFC cannot obtain energy reliably. In this paper, the control strategy of DPFC under low AC line current condition is proposed to prevent the DPFC from losing control under low current condition to protect DPFC equipment. The rationality and engineering applicability of the proposed strategy are verified by experimental results of Hu Zhou DPFC project.