Patent ID: 8842401
Filing Date: 2014-09-23
Classification: G01R,H02H

Abstract:
1. A protection system for a DC electrical power network, the system having: at least one convertor for connection of a power supply or load to the network, the convertor having an output capacitor; one or more circuit breaker arrangements which on activation isolate electrical faults within the network; one or more fault detectors including a sensor for measuring the voltage drop, V a fault type identification arrangement which receives from the fault detectors the measured rates of change of current, di/dt, determines therefrom second derivatives of current, d2i/dt2, across the capacitances, and identifies fault types from the second derivatives, wherein the or each fault detector measures an inductance of a respective section of the network, the system being configured to activate one or more of the circuit breaker arrangements in response to measured inductances which are indicative of a fault, and the inductance of the respective section is determined from V