Abstract: An electrical power system includes an electric power source, for example, an electrical machine, capable of supplying AC power to a load; a power converter connected to the electric power source; a position estimator for receiving a current feedback signal in Park vector format and providing a synchronous reference frame without the need, for example, of a rotor position sensor in the electrical machine; and a controller configured to provide a voltage command for controlling the power converter, the controller receiving the current feedback signal and a current reference in Park vector format and using the synchronous reference frame, the current feedback signal, and the current reference to produce the voltage command.