Electronic phase shift and speed governor

Abstract

A digital electronic governor controls and stabilizes the electrical power output delivered to an output circuit by an AC alternator having a rotating shaft driven by a source. The governor provides a first relatively fast acting governing function operatively responsive to phase shift of the electrical power output relative to the rotating shaft corresponding to changes in load at the output circuit. The first governor stabilizes the phase shift of the electrical power output at a specified phase lag interval relative to the shaft rotation. The electronic governor also provides a second governing function operatively responsive to relatively slower inertial changes in the speed of rotation of the shaft, corresponding to changes in the power level of the AC alternator. This second governor stabilizes the rotating shaft at a specified speed of rotation, e.g., 60 cycles per second. The first governor generates load signals in response to the measured phase shift deviation from a standard phase lag interval. The electronic governor also includes a sequence of dump loads and switching means operatively responsive to the load signals for switching dump loads into and out of the output circuit for maintaining the desired standard phase lag interval. The second governor stabilizes speed of rotation of the alternator shaft by calculating and specifying the desired phase lag interval standard. The second governor therefore sets the standard for the first governor, and the first governor in turn controls the dump loads.