Abstract:Flexible substation based on AC/DC hybrid power distribution technology is a major trend for future

distribution network development.It has attracted wide attention due to multiple functions such as itsmultiterminal interfaces for medium/low and AC/DC voltage flexible power flow control multi-modal energy intervention,fault current limiting and isolation.The bidirectional DC/ACconverter is an important part of the flexible bstation which can realize the bidirectional flow of energy between the low voltage AC and DC ports.The study for bidirectional DC/AC converter control strategy is an urgent need for the safe and reliable operation.Taking AC/DC distribution network and flexible substation demonstration project in Zhangbei as an example according to different control objectives of bidirectional DC/AC converters it was reviewed from key control techniques such as harmonic compensation unbalanced voltage suppression and multi-machineparallel c connection.The trend for bidirectional DC/AC converter control strategy of flexible substation was discussed which provides reference for the construction of flexible substation project.

Key words: flexible substation;bidirectional DC/AC converter;harmonic compensation;unbalanced voltage suppression;multimachine parallel