Patent ID: 8265908

Claim:
A method of testing an interlocking functionality of a first Intelligent Electronic Device (IED) connected to a communication network and adapted to control a first switching device of a substation of an electric power system, the method comprising: preparing, by the first IED, an interlocking response indicating at least one of a release and blocking property of the first switching device; determining, by a testing device different from the first IED, an interlocking status indicating at least one of a release and blocking property of the first switching device; and determining, in the testing device, a dynamic substation topology that is representative of at least a part of the substation and inferred from a standardized description of a static substation topology and from a dynamic switch status of a second switching device of the substation, wherein the testing device determines the interlocking status based on the determined dynamic substation topology and interlocking rules.