Construction of a current injection unit for marine applications

This paper presents the design and operation of a portable Current Injection Unit (CIU) to be used in conjunction with the Active Impedance Estimation (AIE) technique for fault location in DC electrical distribution systems. The AIE technique injects a current transient into the system and monitors the resultant voltage transient. By combining these measurements in the frequency domain, the real and reactive components of system impedance can be estimated and the reactance can be used to indicate fault location. The prototype has been tested experimentally for short circuit faults and is shown to be effective. The portable unit can be used to test the AIE algorithm on more complex DC distribution systems.