Power conversion equipment, DC power transmission system, and a method of controlling the power conversion device

摘要

PROBLEM TO BE SOLVED: To stop a plurality of unit converters in a short time when it was detected that overcurrent flowed through a group of the unit converters.SOLUTION: A power conversion device 102a comprises a plurality of groups of unit converters 106 in each of which groups a plurality of unit converters 108 each comprising a switching element allowing the voltage of a capacitor to output are connected in series, and converts system current, which is alternate current, into direct current or direct current into alternate current. The power conversion device comprises: an arm voltage command value generating unit 311 for generating and outputting a command value to the unit converters 108; an overcurrent detection unit 117 for detecting overcurrent flowing through the group of unit converters 106; and a communication interface unit 118 that transmits an operation command frame to each unit converter 108 at a prescribed cycle on the basis of the command value generated by the arm voltage command value generating unit 311, and that transmits a stop command frame for emergency stop to each unit converter 108 not depending on the prescribed cycle if the overcurrent detection unit 117 detected overcurrent.