Grid Forming Over Distribution Grid with Renewable Sources and Loads

A system has grid forming capability. A connect-disconnect switch is connectable to a power transmission grid and connectable to a distribution grid that may have renewable energy generation sources and loads. A shunt inverter system comprising a 4-quadrant DC-to-AC inverter and a battery power source is connectable to the distribution grid. A controller controls the connect-disconnect switch to connect and disconnect the distribution grid from the power transmission grid, or disconnect a first segment of the distribution grid from a second segment of the distribution grid. The controller operates the shunt inverter system to provide power factor correction to the distribution grid under normal operation. The controller operates the shunt inverter system with switching and current control instructions to enable grid forming and sustaining of continued operation of the distribution grid.