A starter/generator system for an aircraft engine, the starter/generator system comprising: a three-phase squirrel cage induction machine ; and a first three-phase inverter/converter/controller, ICC, unit operatively coupled to said three phase squirrel cage induction machine through a first electrical path, said ICC unit comprising: a three-phase inverter/converter electrically coupled to said three phase squirrel cage induction machine ; a bidirectional DC-DC converter electrically coupled to said three phase inverter/converter ; and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode and to determine the rotor angle by integrating a summation of an estimated rotor speed and a slip speed during a generate mode; wherein during a start mode, logic in said digital control board configures said starter/generator system into a combination of induction motor using the induction machine , three phase DC-AC inverter using the inverter/converter , and DC-DC boost converter using the bidirectional DC-DC converter , and during a generate mode, the logic in said digital control board configures said starter/generator system into a combination of induction generator using the induction machines , three phase AC-DC converter using the inverter/converter , and DC-DC buck converter using the bidirectional DC-DC converter . a three-phase squirrel cage induction machine ; and a first three-phase inverter/converter/controller, ICC, unit operatively coupled to said three phase squirrel cage induction machine through a first electrical path, said ICC unit comprising: a three-phase inverter/converter electrically coupled to said three phase squirrel cage induction machine ; a bidirectional DC-DC converter electrically coupled to said three phase inverter/converter ; and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode and to determine the rotor angle by integrating a summation of an estimated rotor speed and a slip speed during a generate mode; a three-phase inverter/converter electrically coupled to said three phase squirrel cage induction machine ; a bidirectional DC-DC converter electrically coupled to said three phase inverter/converter ; and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode and to determine the rotor angle by integrating a summation of an estimated rotor speed and a slip speed during a generate mode; wherein during a start mode, logic in said digital control board configures said starter/generator system into a combination of induction motor using the induction machine , three phase DC-AC inverter using the inverter/converter , and DC-DC boost converter using the bidirectional DC-DC converter , and during a generate mode, the logic in said digital control board configures said starter/generator system into a combination of induction generator using the induction machines , three phase AC-DC converter using the inverter/converter , and DC-DC buck converter using the bidirectional DC-DC converter . <EOS>