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EP-4742600-A2 - INITIALIZATION AND SYNCHRONIZATION FOR PULSE POWER IN A NETWORK SYSTEM

EP4742600A2EP 4742600 A2EP4742600 A2EP 4742600A2EP-4742600-A2

Abstract

In one embodiment, a method comprises identifying at a first powered device in communication with power sourcing equipment, a second powered device in communication with the first powered device, wherein the first powered device is receiving high voltage pulse power from the power sourcing equipment, notifying the power sourcing equipment of the second powered device at the first powered device, and performing a low voltage power initialization at the first powered device with the second powered device before passing the high voltage pulse power to the second powered device. The first powered device comprises a local isolation switch for a first low voltage pulse power initialization with the power sourcing equipment at start-up of the first powered device and for receiving the high voltage pulse power from the power sourcing equipment and an output isolation switch for said low voltage power initialization with the second powered device and for passing the high voltage pulse power to the second powered device.

Inventors

  • ARDUINI, DOUGLAS PAUL
  • BAEK, SUNG KEE
  • O'BRIEN, RICHARD ANTHONY
  • GOERGEN, JOEL RICHARD
  • JONES, CHAD M.
  • POTTERF, JASON DEWAYNE
  • LI, RUQI

Assignees

  • Cisco Technology, Inc.

Dates

Publication Date
20260513
Application Date
20201014

Claims (8)

  1. A method comprising: identifying at a first powered device in communication with power sourcing equipment, a second powered device in communication with the first powered device, wherein the first powered device is receiving high voltage pulse power from the power sourcing equipment; notifying the power sourcing equipment of the second powered device at the first powered device; and performing a low voltage power initialization at the first powered device -with the second powered device before passing the high voltage pulse power to the second powered device; wherein the first powered device comprises: a local isolation switch for a first low voltage pulse power initialization with the power sourcing equipment at start-up of the first powered device and for receiving the high voltage pulse power from the power sourcing equipment; and an output isolation switch for said low voltage power initialization with the second powered device and for passing the high voltage pulse power to the second powered device.
  2. The method of claim 1 wherein the high voltage pulse power comprises pulses of power transmitted at or above 60 volts.
  3. The method of any of claims 1 to 2 wherein the power sourcing equipment performs a safety check with the second powered device.
  4. The method of any of claims 1 to 3 wherein said notifying the power sourcing equipment of the second powered device comprises communicating timing adjustments based on changes in line capacitance due to the second powered device.
  5. The method of any of claims 1 to 4 wherein said low voltage power initialization is repeated for each phase in a multi-phase pulse power system in which pulses are offset from one another between phases.
  6. The method of any of claims 1 to 5 wherein one of the first and second powered devices is configured to operate as another power sourcing equipment node for at least one downstream device.
  7. An apparatus comprising; means for identifying at a first powered device in communication with power sourcing equipment, a second powered device in communication with the first powered device, wherein the first powered device is receiving high voltage pulse power from the power sourcing equipment; means for notifying the power sourcing equipment of the second powered device at the first powered device; means for performing a low voltage power initialization at the first powered device -with the second powered device before passing the high voltage pulse power to the second powered device; a local isolation switch for a first low voltage pulse power initialization with the power sourcing equipment at start-up of the first powered device and for receiving the high voltage pulse power from the power sourcing equipment; and an output isolation switch for said low voltage power initialization with the second powered device and for passing the high voltage pulse power to the second powered device.
  8. The apparatus of claim 7, further comprising means for performing the method of any of claims 2 to 6.

Description

TECHNICAL FIELD The present disclosure relates generally to power transmittal in a network, and more particularly, to initialization and synchronization for pulse power in a network system. BACKGROUND Power over Ethernet (PoE) is a technology for providing electrical power over a wired telecommunications network from power sourcing equipment (PSE) to a powered device (PD) over a link section. In conventional PoE systems, power is delivered over the cables used by the data over a range from a few meters to about one hundred meters. When a greater distance is needed or fiber optic cables are used, power must be supplied through a local power source such as a wall outlet due to limitations with conventional PoE. Furthermore, today's PoE systems have limited power capacity, which may be inadequate for many classes of devices. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates an example of a communications network in which embodiments described herein may be implemented.Figure 2 depicts an example of a network device useful in implementing embodiments described herein.Figure 3 is a block diagram illustrating components of a pulse power system, in accordance with one embodiment.Figure 4 is a flowchart illustrating low voltage initialization for a pulse power system, in accordance with one embodiment.Figure 5 is a flowchart illustrating high voltage initialization for the pulse power system, in accordance with one embodiment.Figure 6 is a diagram illustrating high voltage initialization pulse limits within a safe region, in accordance with one embodiment.Figure 7 is a flowchart illustrating a cable capacitance and safety test, in accordance with one embodiment.Figure 8 is a block diagram illustrating an extended safe power system for delivering pulse power, in accordance with one embodiment.Figure 9A is an example of a circuit for use in the cable capacitance and safety test of Figure 7, in accordance with one embodiment.Figure 9B illustrates current and voltage at a cable corresponding to changes in state of switches in the circuit of Figure 9A.Figure 9C is an example of a circuit for use in another cable capacitance and safety test, in accordance with one embodiment.Figure 9D illustrates current and voltage at a cable corresponding to changes in state of switches in the circuit of Figure 9C.Figure 10A is a block diagram illustrating a circuit for use in synchronization. in accordance with one embodiment.Figure 10B illustrates voltage at a cable corresponding to changes in state of switches in the circuit of Figure 10A.Figure 11A is a block diagram illustrating a circuit for use in the low voltage initialization of Figure 4, in accordance wi th one embodiment.Figure 11B illustrates cable voltage and housekeeping power corresponding to changes in state of a power sourcing equipment switch in the circuit of Figure 11A.Figure 11C is an example of a low voltage start-up circuit, in accordance with one embodiment.Figure 12A is a block diagram illustrating details of a housekeeping power circuit of Figure 11A.Figure 12B illustrates details of the housekeeping power circuit of Figure 11C.Figure 12C is a block diagram of the housekeeping power circuit of Figure 12B.Figure 13A is a block diagram illustrating a circuit for use in the high voltage initialization of Figure 5, in accordance with one embodiment.Figure 13B illustrates cable voltage and housekeeping power corresponding to changes in state of a power sourcing equipment switch in the circuit of Figure 13A.Figure 14 is a block diagram of a circuit illustrating a safety crowbar/shorting relay added to a high voltage source in the circuit of Figure 8.Figure 15 shows a cable with optical fibers and two twisted pairs connecting power sourcing equipment to a powered device for delivery of extended safe power, in accordance with one embodiment.Figure 16 illustrates details of one of the twisted pairs shown in Figure 15, in accordance with one embodiment.Figure 17 illustrates an example of power and data distribution to a plurality of powered devices, in accordance with one embodiment.Figure 18 is a simplified block diagram illustrating an example of voltage and power levels between the power sourcing equipment and powered device in an extended safe power system, in accordance with one embodiment.Figure 19 is another simplified block diagram illustrating an example of voltage and power levels between the power sourcing equipment and the powered device in the extended safe power system, in accordance with one embodiment.Figure 20 is a block diagram illustrating an example of a multi-node three-phase pulse power system, in accordance with one embodiment.Figure 21 illustrates an example of three-phase pulse power voltage and current for the system shown in Figure 20 with constant power loading from endpoint nodes.Figure 22 illustrates a simplified circuit of a two-phase pulse power system on a cable with four-pair wire, in accordance with one embodiment.Figure 23 illust