A generator system that includes a three-phase AC machine and an active rectifier bridge employing low on-resistance MOSFET switches for converting the AC current from the machine to a DC current. The system also includes a switch control circuit to switch the MOSFET switches in synchronization with the three-phase current flow. The system determines the phase-to-ground voltages of the machine as inputs to the switch control circuit. The control circuit calculates the phase-to-phase voltages from the phase-to-ground voltages. The control circuit then determines if each of the phase-to-phase voltages is above or below first and second predetermined threshold voltages, where if the phase-to-phase voltage is above the first threshold voltage, the control circuit closes the switch, and if the phase-to-phase voltage is below the second threshold voltage, the control circuit opens the switch.