Abstract: The present invention relates to a method of monitoring oscillations that are liable to interact in an electrical power network, in dependence on measurement of AC waveforms in the electrical power network. The method comprises receiving first waveform data corresponding to an electrical quantity in each phase of at least two phases of three-phase AC waveforms at a location in the electrical power network. The method further comprises applying a transformation to the first waveform data to provide therefrom second waveform data corresponding to an electrical quantity at the location in a single phase representation, the second waveform data depending on the at least two phases.

Abstract: A method of controlling an electrical power network in which a sudden event which may lead to loss or excess of generation or load. The electrical power network comprises plural controllers, each controller configured to control an apparatus connected to the power network at a different respective location in the electrical power network. The method comprises determining the occurrence of the sudden and receiving synchronised quantities in each of the controllers each of the quantities corresponding to one of frequency and angle at respective different locations in the electrical power network. The method further comprises generating a control output from each controllers in dependence on the received plural quantities, each control output controlling its respective apparatus, each controller generating the control output independent of operation of any other controller and on an ongoing basis in dependence on ongoing receipt of the plural quantities.

Abstract: This application relates to methods and apparatus for fault protection in a DC power transmission network or grid that aid in determining the location of a fault in the network. The method involves, in the event of a fault, controlling at least one current limiting element of the network so as to limit a fault current flowing to below a first current level which is within the expected current operating range of the network in normal operation, i.e. a safe level. The fault current is then controlled to maintain a non-zero level of fault current flow and the characteristics of the fault current flow at different parts of the network are determined by fault current detection modules. The location of the fault is then determined based on the determined characteristics.

Abstract: A method of controlling an electrical power network in which a sudden event which may lead to loss or excess of generation or load. The electrical power network comprises plural controllers, each controller configured to control an apparatus connected to the power network at a different respective location in the electrical power network. The method comprises determining the occurrence of the sudden and receiving synchronised quantities in each of the controllers each of the quantities corresponding to one of frequency and angle at respective different locations in the electrical power network. The method further comprises generating a control output from each controllers in dependence on the received plural quantities, each control output controlling its respective apparatus, each controller generating the control output independent of operation of any other controller and on an ongoing basis in dependence on ongoing receipt of the plural quantities.

Abstract: The present invention relates to a method of monitoring oscillations that are liable to interact in an electrical power network, in dependence on measurement of AC waveforms in the electrical power network. The method comprises receiving first waveform data corresponding to an electrical quantity in each phase of at least two phases of three-phase AC waveforms at a location in the electrical power network. The method further comprises applying a transformation to the first waveform data to provide therefrom second waveform data corresponding to an electrical quantity at the location in a single phase representation, the second waveform data depending on the at least two phases.

Abstract: This application relates to methods and apparatus for fault protection in a DC power transmission network or grid that aid in determining the location of a fault in the network. The method involves, in the event of a fault, controlling at least one current limiting element of the network so as to limit a fault current flowing to below a first current level which is within the expected current operating range of the network in normal operation, i.e. a safe level. The fault current is then controlled to maintain a non-zero level of fault current flow and the characteristics of the fault current flow at different parts of the network are determined by fault current detection modules. The location of the fault is then determined based on the determined characteristics.