Utilizing Spread Spectrum Time Domain Reflectometry (SSTDR) to Automatically Detect Ground Faults in Live Shipboard Control Systems

The use of Spread Spectrum Time Domain Reflectometry (SSTDR) that has already been proven in aerospace applications will be adapted and optimized for detection and location of wiring faults in shipboard systems. SSTDR is the only technology that allows MCS fault detection and isolation, on fully powered systems without taking the console offline or disconnecting any of the system components, thus accelerating the mitigation and repair process. SSTDR detects and locates a full range of impedance changes and is therefore suitable for detecting when the minimum isolation resistance of 250K ohms, and locating the fault within 3% of the cable length. In contrast to traditional TDR methods that inject disruptive signals and require decoupling, LiveWire"s SSTDR technology injects a very low amplitude Pseudo Noise (PN) code, which is well below a typical noise floor ( The Phase 1 effort will demonstrate the ability to detect and locate a ground fault at a single location. The Phase 2 effort will leverage a multiplexed solution leveraging LiveWire"s ASIC to detect and locate simultaneous grounds, including signal returns and signal shields connected to the ship"s hull. We envision an ASIC SSTDR device integrated and leveraged within a ship"s health management system architecture.