Power from the dc outputs of wind-generated power collection nodes is converted to ac power of suitable quality for injection into an electric power grid. Conversion is accomplished by current regulation of the dc outputs of the wind-generated power collection nodes to the input of each one of multiple inverters in a system, with each inverter outputting multiple phase currents that are out of phase with the multiple phase currents outputted from all other inverters in the system. The multiple phase currents from all of the inverters in a system are connected to the secondary windings of a phase transformation network that produces a three phase current output having a step-shaped waveform for injection into the electric power grid. Alternatively the dc input to each one of the multiple inverters may be a combination of the dc outputs of wind-generated power collection nodes and the dc outputs of solar photovoltaic power collection nodes.