Microgrid structure based on back-to-back alternating-direct-current converter and control method

The invention relates to a microgrid structure based on a back-to-back alternating-direct-current converter and a control method. A grid-connected protection terminal is adopted to realize grid-connected point abnormality protection, control a grid-connected point switch and provides a grid-connected switching instruction, and a source load balance control terminal is adopted to realize total balance among output of a distributed-type power generating unit, power of an energy storing system, output of a standby power source and active power of a load when a microgrid is in grid-connected and off-grid running. The back-to-back alternating-direct-current converter is adopted, so that when abnormalities occur outside the microgrid, grid-connected and off-grid smooth switching can be realized with power-off; under the circumstance that power supply of a power distribution network is stopped, the microgrid can smoothly transit to be in off-grid running, so that power supply reliability aiming at the load in the microgrid is guaranteed effectively.