The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 21, 2012
Filed:
Jul. 23, 2009
Christopher G. Bright, Nottingham, GB;
Christopher G. Bright, Nottingham, GB;
Rolls-Royce PLC, London, GB;
Abstract
Protection arrangements and methods of operating protection arrangements are important in order to maintain operability with regard to electrical power distribution networks. Such networks generally comprise grids or meshes of electrical distribution pathways from generators and electrical loads. Faults may occur within the network and circuit breakers or other protection elements are utilised to isolate such faults. A number of regimes for protection are known but problems can arise with regard to ensuring an appropriate pan of the distribution network is isolated. By providing circuit breakers which have a time grade margin compared to other circuit breakers which is proportional to an inverse current-time logarithmic relationship between a fault electrical current divided by a major contribution electrical current to the circuit breaker operation can be achieved which is sufficiently quick for high electrical fault currents but incorporates a time delay for low electrical currents which may have a more transient nature.