A method of protecting an electromechanical power transfer system from
excessive peak electrical potentials, the power transfer system
comprising a prime mover, a dynamoelectric machine coupled to the prime
mover for generating multiphase alternating current (AC) power, and at
least one multiphase AC electrical load coupled to the dynamoelectric
machine by way of a multiphase AC power bus, the dynamoelectric machine
having a control coil responsive to control current for varying power
supplied to the electrical load, comprises the steps of: analysing
electrical potentials on the power bus to generate analysed power bus
characteristics; comparing the analysed power bus characteristics to
predetermined power bus characteristics; simultaneously shunting power
across the power bus and reducing control current to the control coil for
the dynamoelectric machine when the analysed power bus characteristics
approximate the predetermined power bus characteristics to reduce the
measured electrical potentials; and simultaneously terminating the shunt
of power across the power bus and restoring the level of control current
to the control coil for the dynamoelectric machine after a selected delay
period to automatically restore power to the electrical load.