Patent ID: 6400547
Filing Date: 2002-06-04
Classification: H01H,H02H,H02J,Y02E,Y04S

Abstract:
A method of monitoring a switching device, the method which comprises:monitoring state parameters in a switching device by recording and evaluating sensor signals of electrical sensors susceptible to an interference caused by at least one of an external electrical field and an external magnetic field; determining if and when the sensor signals are disturbed signals by evaluating a temporal sequence of the sensor signals; applying a passive interference suppression using a passive interference suppression device; applying an active interference suppression by generating evaluation signals corresponding to the undisturbed signals, with the sensors recording steady-state signals and transient signals of switching states of the switching device; deriving a state signal from each of the steady-state signals by electronically processing the steady-state signals, the state signal following a state change after a given time interval if a new state remains unchanged within the given time interval, and forming an interference-suppressed steady-state signal; deriving a further state signal from each of the transient state signals of slow actuators, by electronically processing the transient state signals, the further state signal following a further state change after a further given time interval if a further new state remains unchanged within the further given time interval, and forming an interference-suppressed transient state signal; logically combining transient state signals of fast actuators with the interference-suppressed steady-state signals and the steady-state signals not subjected to interference suppression; and as a result of the combining step, selectively performing at least one of the steps of enabling a signal path of a transient state signal, disabling the signal path of the transient state signal, permanently storing the transient state signal after being temporarily stored, and erasing the transient state signal after being temporarily stored.