Network construction type energy storage converter with grid-connected and off-grid switching function

The invention relates to the technical field of electrical control, in particular to a network construction type energy storage converter with a grid-connected and off-grid switching function. The system has a grid-connected operation mode and an off-grid operation mode, and can adapt to a power grid environment to be automatically switched from the grid-connected operation mode to the off-grid operation mode. The grid-forming type energy storage converter works in a grid-connected mode when connected to a power grid, active power and reactive power output in a grid-connected mode can be controlled, and a phase-locked loop does not need to be synchronized with the power grid; the amplitude and the frequency of the alternating current side voltage can be controlled in the off-grid operation mode; when the grid-connected point is disconnected from the power grid, the energy storage converter can automatically switch from the grid-connected operation mode to the off-grid operation mode to supply power to the loa