Using impedance analysis for fault detection in power delivery systems

An apparatus comprising:

• a digital signal processor configured to be connected to a wire that carries power from a power transmitter to a power receiver, wherein the digital signal processor is configured to:
• apply onto the wire, successive chirp pulses, each chirp pulse comprising a sequence of waveforms at a plurality of frequencies and successive chirp pulses being separated in time by a quiet period;
• obtain a signal on the wire resulting from the successive chirp pulses;
• analyze an impedance of a signal at two or more frequencies of the plurality of frequencies by determining, at each of the two or more frequencies, at least one of an impedance magnitude or an impedance phase of the signal at that frequency, and comparing the impedance magnitude or the impedance phase at each of the two or more frequencies with respect to a reference impedance derived from the signal on the wire to determine whether there is an indication of an impedance-based fault on the wire;
• and
• generate a disconnect control signal in response to determining an indication of the impedance-based fault;
• and
• a disconnect device coupled to the wire and responsive to the disconnect control signal to disconnect the power from the wire.

A method comprising:

• at a power transmitter, applying to a wire successive chirp pulses, each chirp pulse comprising a sequence of waveforms at a plurality of frequencies and successive chirp pulses being separated in time by a quiet period;
• obtaining a signal on the wire resulting from the successive chirp pulses;
• analyzing an impedance of the signal on the wire resulting from the successive chirp pulses at two or more frequencies of the plurality of frequencies, wherein analyzing comprises determining, at each of the two or more frequencies, at least one of an impedance magnitude or an impedance phase of the signal at that frequency, and comparing the impedance magnitude or the impedance phase at each of the two or more frequencies with respect to a reference impedance to determine whether there is an indication of an impedance-based fault on the wire;
• and
• determining whether to apply relatively high power on the wire for delivery to a power receiver based on the analyzing.

A method comprising:

• applying power to each of a plurality of wire pairs of a cable;
• transmitting and receiving data over the plurality of wire pairs of the cable;
• applying onto the plurality of wire pairs successive chirp pulses, each chirp pulse comprising a sequence of waveforms of a plurality of frequencies and successive chirp pulses being separated in time by a quiet period;
• obtaining signals from the plurality of wire pairs resulting from the successive chirp pulses;
• analyzing an impedance of the signals obtained from the plurality of wire pairs at two or more frequencies of the plurality of frequencies, wherein analyzing comprises determining, at each of the two or more frequencies, at least one of an impedance magnitude or an impedance phase of the signals at that frequency, and comparing the impedance magnitude or the impedance phase at each of the two or more frequencies with respect to a reference impedance to determine whether there is an indication of an impedance-based fault on a given wire pair of the plurality of wire pairs;
• and
• disconnecting the power from the given wire pair in response to determining an indication of the impedance-based fault.