Abstract: A fault detection system for detecting a fault condition in a direct current (DC) system. The system may include a DC power transmitter to energize a cable and a DC power receiver connected to the cable. A signal generator at the receiver employs orthogonal frequency division multiplexing (OFDM) and combines symbols for messaging or data communications with redundant symbols dedicated to fault detection. At a signal receiver, the transmitted OFDM signal is used to measure changes in the channel transfer function by monitoring changes in a parameter of the received redundant symbols. The redundant symbols need not be decoded to detect a greater-than-threshold change in the transfer function that is indicative of a fault on the cable.

Abstract: A fault detection system and method for detecting a fault condition in a direct current (DC) system. A power transmitter energizes a cable with electrical power. A power receiver connected to the cable provides the electrical power to a load. At the power receiver, a signal generator coupled to the cable generates and propagates a deterministic signal on the cable. At the power transmitter, a fault detector is coupled to the cable to receive the deterministic signal and noise after propagation through the cable. The fault detector has a plurality of filter branches with each of the filter branches having an associated bandwidth. Adjusting a gain of one or more of the filter branches in response to a signal-to-noise ratio of the cable. The cable is deenergized when a fault is detected on at least one of the filter branches.

Abstract: A fault detection system for detecting a fault condition on a direct current (DC) transmission line. The system may include a transmitter including a DC source to energize a transmission line and a receiver connected to the transmission line and including a signal generator to generate a periodic signal at or near a resonant frequency. The transmitter may include a termination impedance higher than a characteristic impedance of the transmission line to reflect substantially all the periodic signal to establish a standing wave on the transmission line. The transmitter may include a first fault detection circuit coupled to the transmission line to detect an amplitude attenuation of the standing wave of more than a threshold amount and, in response, to disconnect the transmission line from the DC source.

Abstract: A fault detection system for detecting a fault condition in a direct current (DC) system. The system may include a DC power transmitter to energize a cable and a DC power receiver connected to the cable. A signal generator at the receiver employs orthogonal frequency division multiplexing (OFDM) and combines symbols for messaging or data communications with redundant symbols dedicated to fault detection. At a signal receiver, the transmitted OFDM signal is used to measure changes in the channel transfer function by monitoring changes in a parameter of the received redundant symbols. The redundant symbols need not be decoded to detect a greater-than-threshold change in the transfer function that is indicative of a fault on the cable.

Abstract: A fault detection system for detecting a fault condition on a direct current (DC) transmission line. The system may include a transmitter including a DC source to energize a transmission line and a receiver connected to the transmission line and including a signal generator to generate a periodic signal at or near a resonant frequency. The transmitter may include a termination impedance higher than a characteristic impedance of the transmission line to reflect substantially all the periodic signal to establish a standing wave on the transmission line. The transmitter may include a first fault detection circuit coupled to the transmission line to detect an amplitude attenuation of the standing wave of more than a threshold amount and, in response, to disconnect the transmission line from the DC source.

Abstract: A fault detection system for detecting a fault condition in a direct current (DC) system. The system may include a transmitter including a DC source to energize a cable and a receiver connected to the cable and including a signal generator to generate a periodic signal. The transmitter may include a termination impedance matched to the characteristic impedance of the cable to absorb substantially all the periodic signal. The transmitter may include a fault detection circuit coupled to the cable to detect changes in the frequency response of the cable by tracking changes in the envelope of the power of the periodic signal and outputting a fault signal if the rate-of-change of the envelope of the power of the period signal exceeds a threshold level.

Abstract: A fault detection system for detecting a fault condition on a direct current (DC) transmission line. The system may include a transmitter including a DC source to energize a transmission line and a receiver connected to the transmission line and including a signal generator to generate a periodic signal at or near a resonant frequency. The transmitter may include a termination impedance higher than a characteristic impedance of the transmission line to reflect substantially all the periodic signal to establish a standing wave on the transmission line. The transmitter may include a first fault detection circuit coupled to the transmission line to detect an amplitude attenuation of the standing wave of more than a threshold amount and, in response, to disconnect the transmission line from the DC source.