Rolls-royce Corporation

Alstom Technology Limited

Schneider Electric Energy UK Ltd.

Adam Dysko

David Reginald Trainer

Stuart J Galloway

Graeme Burt

Ryan M Tumilty

Matthew Ingham

A phase angle drift method for loss of mains/grid protection is disclosed. According to one aspect, an accumulated electrical phase angle drift derived from the difference between the current measured local frequency and the estimated frequency using historical data is compared to an angle threshold. An estimated grid frequency may be calculated based on the historical delay, and the window, over which the estimated frequency is calculated. An addition/subtraction of a phase angle offset value is calculated for a half cycle is performed when the frequency difference between the estimated frequency fand the measured frequency fis greater or equal to a first determined value.

Phase angle drift method for loss of mains/grid protection

Previously, electrical power systems have been analyzed to provide theoretical fault levels values for different zones of an electrical power distribution system based upon a worse case scenario. However, existing electrical loads will in practice provide a more adaptable and higher fault level. By monitoring and identifying an I-V characteristic upon switching electrical load in practical operation an actual default level at particular nodes in a power distribution system is determinable. In such circumstances decisions with regard to the connectability of further electrical generators or loads at particular parts and zones of an electrical power distribution system can be quantified by reference to the actual fault level rather than the theoretical worse case scenario level and therefore avoid unnecessary upgrading of transmission equipment or denying access to the electrical power system.

Electrical distribution networks

Growing community of inventors

Motherwell, United Kingdom

Adam Dysko