Grid-connected power supply system and grid-connected device of data center

The invention provides a grid-connected power supply system and a grid-connected device of a data center. The grid-connected power supply system at least comprises a first generator set and a power supply line, the input end of the power supply line is connected with an external power supply; wherein the output end of the power supply line is connected with load equipment of the data center, the first generator set is connected with the input end of the power supply line through the grid-connected device, and the grid-connected device is used for rectifying, inverting and transforming alternating current output by the first generator set, so that the output alternating current meets the synchronization condition. Therefore, the first generator set can provide supplement and support for anexternal power supply source; when the external power supply source is limited or the maximum capacity of the external power supply source is exceeded due to the rise of the load power of the data center; the difference of po