A power signal processing system and method for protection of a power system has a signal input unit for receiving a signal representing a condition of a power system; a plurality of processing units cooperating to apply to the received signal a predetermined process including a series of predetermined different computations thereby producing a control signal for controlling operation of the power signal processing system. The respective processing units operate to perform the predetermined different computations, respectively. A control unit is provided for controlling transfer of data among the processing units so that the different computations are applied, successively, to the received signal thereby producing the control signal which is used to cause, for example, the issue of a cut-off command to a circuit breaker.