Arc fault detection and protection in a digital electricity power distribution system

Arc fault protection for a digital electricity distribution system that provides power to a device. The system includes an arc fault circuit interrupter (“AFCI”) and a controller. The controller is connected to the AFCI. The controller is operable to control the AFCI to disable power to the device. The controller includes a processor and a memory. The controller is configured to transmit a digital electricity energy packet through the AFCI to the device, measure an amount of error associated with the digital electricity energy packet, evaluate the amount of error associated with the digital electricity energy packet, determine whether an arc fault condition is present based on the evaluation of the amount of error associated with the digital electricity energy packet, and control the AFCI to disable power to the device when the arc fault condition is determined to be present.

FIELD

Embodiments described herein relate to safety protection devices and methods for a power distribution system.

SUMMARY

Digital electricity is a power format where electrical power is distributed in discrete, controllable units of energy or packets. Unlike traditional analog power systems, individual packets of energy can be associated with data or digital information that can be used to control the operation of a device receiving the power of a power system itself. As a result of the differences between conventional, analog power and digital electricity, conventional fault detection techniques either cannot be used with digital electricity or cannot be used effectively (e.g., safely) with digital electricity.

An arc fault is a high power discharge of electricity between two or more conductors. Arc faults can produce currents from a few Amps up to thousands of Amps and can vary in both strength and duration. An arc fault occurs when, for example, loose or corroded wiring connections create an intermittent contact that causes electrical current to spark or arc between contact points. The arcing generates heat. The generated heat can break down, for example, the insulation surrounding individual conducting wires, which can lead to an electrical fire. An arc fault protection device (e.g., an arc fault circuit interrupter [“AFCI”]) is any device that is designed to guard against arc faults. Conventional arc fault protection devices monitor alternating currents for an unwanted arcing condition (e.g., based on magnitude and/or frequency). However, such conventional arc fault protections are ineffective for digital electricity systems in which power is transmitted in discrete energy packets.

Embodiments described herein provide arc fault protection for a digital electricity distribution system for providing power to a device. The system includes an arc fault circuit interrupter (“AFCI”) and a controller. The controller is connected to the AFCI. The controller is operable to control the AFCI to disable power to the device. The controller includes a processor and a memory. The controller is configured to transmit a digital electricity energy packet through the AFCI to the device, measure an amount of error associated with the digital electricity energy packet, evaluate the amount of error associated with the digital electricity energy packet, determine whether an arc fault condition is present based on the evaluation of the amount of error associated with the digital electricity energy packet, and control the AFCI to disable power to the device when the arc fault condition is determined to be present.

In some aspects, the digital electricity energy packet includes an energy payload and a data payload.

In some aspects, the amount of error is associated with one selected from the group consisting of: a loss of data in the data payload; an amount of attenuation of the data payload; and an amount of distortion associated with the data payload.

In some aspects, the power provided to the device is between 400 W and 600 W.

In some aspects, the controller is further configured to determine whether one of a cross-line fault condition, an in-line fault condition, a ground fault condition, or a neutral fault condition is present.

In some aspects, the amount of error associated with the digital electricity energy packet is an aggregate of errors from unreceived data in a series of energy packets.

In some aspects, the amount of error associated with the digital electricity energy packet is an aggregate of errors from unreceived data over a predetermined period of time.

In some aspects, the controller is further configured to determine whether the arc fault condition is present based on a comparison of the amount of error to at least one of a frame loss rate threshold value, an attenuation threshold value, a signal-to-noise ratio threshold value.

In some aspects, the arc fault condition is caused by at least one of an improper connection, a loose connection, excessive cable length, or external noise.

In some aspects, the controller is further configured to determine whether the arc fault condition is present based on the evaluation of the amount of error based on a comparison to a predetermined data packet.

In some aspects, the controller is further configured to determine whether the arc fault condition is present based on a percentage correlation of the digital electricity energy packet and the predetermined data packet.

Embodiments described herein provide a power distribution system for providing power to a device. The system includes a power transmitter, a power receiver, an arc fault circuit interrupter (“AFCI”), and a controller. The power transmitter is configured to receive at least one of an alternative current (“AC”) input power and a direct current (“DC”) input power and generate digital electricity energy packets for distribution through the system. The power receiver is electrically connected to the power transmitter for receiving the digital electricity energy. The AFCI is connected between the power transmitter and the power receiver. The controller is connected to the AFCI. The controller is operable to control the AFCI to disable power from the power transmitter to the power receiver. The controller includes a processor and a memory. The controller is configured to transmit a digital electricity energy packet through the AFCI to the power receiver, measure an amount of error associated with the digital electricity energy packet, evaluate the amount of error associated with the digital electricity energy packet, determine whether an arc fault condition is present based on an evaluation of the amount of error associated with the digital electricity energy packet, and control the AFCI to disable power to the power receiver when the arc fault condition is determined to be present.

In some aspects, the digital electricity energy packet includes an energy payload and a data payload.

In some aspects, the amount of error is associated with one selected from the group consisting of: a loss of data in the data payload; an amount of attenuation of the data payload; and an amount of distortion associated with the data payload.

Embodiments described herein provide a method for disabling power to a device in a digital electricity system. The digital electricity system includes an arc fault circuit interrupter (“AFCI”). The method includes transmitting a digital electricity energy packet through the AFCI to the device, measuring an amount of error associated with the digital electricity energy packet, evaluating the amount of error associated with the digital electricity energy packet, determining whether an arc fault condition is present based on an evaluation of the amount of error associated with the digital electricity energy packet, and controlling the AFCI to disable power to the device when the arc fault condition is determined to be present.

In some aspects, the digital electricity energy packet includes an energy payload and a data payload.

In some aspects, the amount of error is associated with a loss of data in the data payload.

In some aspects, the amount of error is associated with an amount of attenuation of the data payload.

In some aspects, the amount of error is associated with an amount of distortion associated with the data payload.

In some aspects, the power provided to the device is between 400 W and 600 W.

It should be understood that although certain drawings illustrate hardware and software located within particular devices, these depictions are for illustrative purposes only. Functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. In some embodiments, the illustrated components may be combined or divided into separate software, firmware and/or hardware. For example, instead of being located within and performed by a single electronic processor, logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components may be located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not explicitly listed.

DETAILED DESCRIPTION

FIG.1illustrates a system100that includes a digital electricity transmitter or server105. The transmitter105is coupled to a source of alternating current (“AC”) power110(e.g., AC mains power) and one or more sources of direct current (“DC”) power115(e.g., a photovoltaic array, a battery bank, etc.). In some embodiments, the source of AC power110bypasses the transmitter105and provides power to a conventional wall outlet120. The transmitter105is configured to convert the input AC or DC power into digital electricity. Digital electricity can be represented as one or more energy packets that include both energy and data. The digital electricity energy packets are transmitted from the transmitter105to a receiver125.FIG.1illustrates an energy packet for exemplary purposes including a 1.1 millisecond energy payload and a 0.4 millisecond data payload.

The digital electricity is received by the receiver125. In some embodiments, the received digital electricity is received by the receiver125at a voltage of 330V DC. The transmitter105and the receiver125are capable of one-way communication (e.g., transmitter105to receiver125) or two-way communication. The receiver125is configured to receive the digital electricity and determine, for example, if the data portion of an energy packet was received. If the data portion of the energy packet is not received, a fault may have occurred during the transmission of the digital electricity from the transmitter105to the receiver125. The receiver125is also configured to convert the received digital electricity to conventional DC power for further transmission to a first power distribution controller130. In some embodiments, the receiver125is configured to transmit digital electricity to the first power distribution controller130in a similar manner to the transmitter105transmitting digital electricity to the receiver125. In some embodiments, the first power distribution controller130is a Cisco 8U Catalyst Digital Building Series Switch.

The first power distribution controller130is configured to receive power at a lower voltage than the power received by the receiver125. For example, the receiver125includes a DC-to-DC converter that steps down the received voltage to a lower level. Alternatively, the first power distribution controller130is configured to receive power at the same voltage as the receiver125. In such embodiments, the first power distribution controller130can include a DC-to-DC converter that steps down the received voltage to a lower level. In the illustrated embodiment, the first power distribution controller130outputs voltages of between 48V DC and 57V DC. In other embodiments different voltage ranges can be produced (e.g., between 5V DC and 60V DC).

The first power distribution controller130is also configured to relay DC power for further transmission to a second power distribution controller135. In some embodiments, the first power distribution controller130is configured to transmit digital electricity to the second power distribution controller135in a similar manner to the transmitter105transmitting digital electricity to the receiver125. The second power distribution controller135is configured to receive power at a lower voltage than the power received by the first power distribution controller130. For example, the first power distribution controller130includes a DC-to-DC converter that steps down the received voltage to a lower level. Alternatively, the second power distribution controller135is configured to receive power at the same voltage as the first power distribution controller130. In such embodiments, the second power distribution controller135can include a DC-to-DC converter that steps down the received voltage to a lower level. In the illustrated embodiment, the second power distribution controller135outputs voltages of, for example, 24V DC. In other embodiments different voltages can be produced (e.g., between 5V DC and 60V DC). In some embodiments, the second power distribution controller135is a nuLEDs SPICEbox.

The first power distribution controller130and the second power distribution controller135are each configured to be electrically and/or communicatively connected to one or more powered devices. In the illustrated embodiment, the first power distribution controller130is connected to a heating ventilation and air conditioning (“HVAC”) unit140, a refrigerator145, and an entertainment system150. In some embodiments, the connections between the first power distribution controller and the devices140,145, and150are made using Cat 5-Cat 8 Ethernet cables. In some embodiments, both electricity and data are provided over the Ethernet cables in a power-over-Ethernet (“POE”) implementation. In a POE implementation, one or two way communications can be achieved between the first power distribution controller130and the devices140,145, and150.

In the illustrated embodiment, the second power distribution controller135is connected to lights155, curtains/shades160, input controls165, and sensors170. In some embodiments, the connections between the second power distribution controller135and the devices155,160,165, and170are made using CAT 5-CAT 8 Ethernet cables. In some embodiments, both electricity and data are provided over the Ethernet cables in a POE implementation. In a POE implementation, one or two way communications can be achieved between the second power distribution controller135and the devices155,160,165, and170.

A simplified schematic diagram of a digital electricity distribution system200, such as the system100inFIG.1, is illustrated inFIG.2. The distribution system200is configured to regulate the transfer of energy from a source205to a load210. A source controller215is configured to periodically open a switch220for a predetermined period of time (e.g., a sample period). In some embodiments, the switch220is a solid state switch (e.g., a FET). A load capacitor, CLOAD, is electrically connected to the terminals of the load210. The load capacitor, CLOAD, stores energy from the terminals of the load210prior to the switch220being opened. A source resistance, RsouRcE, is electrically connected between the terminals of the source205.

During normal operation, when the switch220is opened, the voltage across the load capacitor, CLOAD, decays as it discharges through the source resistance, RSOURCE, and into the load210. A switch225is configured to isolate the load capacitor, CLOAD, from the load210. In some embodiments, the switch225is a solid state switch (e.g., a FET). When the switch225is opened, the only discharge path for the load capacitor, CLOAD, should be through the source resistance, RSOURCE. However, during, for example, a cross-line fault, resistance from a foreign object (e.g., a person) is introduced into the system200as a leak resistance, RLEAK. The parallel combination of the source resistance, RSOURCE, and leak resistance, RLEAK, significantly increases the rate of voltage decay from the load capacitor, CLOAD.

The voltage across the load capacitor, CLOAD, prior to the switch220being opened is measured by the source controller215. At the end of the sample period and prior to the switch220being closed, the source controller215measures the voltage across the load capacitor, CLOAD, again. The source controller215compares the voltage across the load capacitor, CLOAD, at the two different times to determine if a fault has occurred. If the voltage across the load capacitor, CLOAD, has decayed too quickly (or too slowly), a fault can be registered and the switch220remains opened. A high rate of voltage decay for the load capacitor, CLoAD, indicates a cross-line fault. A low rate of voltage decay for the load capacitor, CLOAD, indicates an in-line fault. If there is no fault condition detected, the switch220and switch225can be closed. Energy is then transferred between the source205and the load210until the next sample period. In some embodiments, the conducting period between sampling periods is referred to as an energy transfer period.

In some embodiments, a communication link230can be provided between the source controller215and a load controller235. In such embodiments, the source controller215can receive the load terminal voltage from the load controller235. In some embodiments, a digital verification code can be exchanged between the source controller215and the load controller235before energy is transferred between the source205and the load210. The power distribution technique described with respect toFIG.2can be applied between any two adjacent power distribution components in the system100ofFIG.1. For example, the source could be the transmitter105and the load could be the receiver125, the source could be the receiver125and the load could be the first power distribution controller130, the source could be the first power distribution controller130and the load could be the second power distribution controller135. In some embodiments, the source is one of the first power distribution controller130or second power distribution controller135and the load is one of the devices140-170.

As described above, the first power distribution controller130and the second power distribution controller135can be configured in a POE implementation to provide both power and data to the devices140-170.FIG.3illustrates a system300for achieving POE between the first power distribution controller130or the second power distribution controller135and the devices140-170. Specifically,FIG.3illustrates a center-tapped isolation transformer for combining data and power on twisted pair cabling. In other embodiments, different techniques for achieving POE can be used.

In some embodiments, a CAT 5-CAT 8 Ethernet cable is used to transfer Ethernet data between the first power distribution controller130or the second power distribution controller135and the devices140-170. That Ethernet cable can also be used to provide, for example, between 400W and 600W of power to the devices140-170. Output conductors of source circuitry305are applied to center tap points on isolation transformers315,320on the source side of the system300. Output conductors of load circuitry310are applied to center tap points on the isolation transformers325,330. On the source side, Ethernet data can be applied to the windings of the transformers315,320. On the load side, the signals corresponding to the Ethernet data are picked up by the transformers325,330. Because the power being transmitted is DC, the signals corresponding to the Ethernet data do not cause excitation in the transformers315,320. As a result, the Ethernet data is not corrupted during transfer.

FIG.4illustrates the transmitter105ofFIG.1in more detail. The transmitter105is electrically and/or communicatively connected to a variety of modules or components of the system100. For example, the transmitter105is connected to the source of AC power110, the one or more sources of DC power115, and the receiver125. The transmitter105includes a controller400, a power input module405, a power output module410, a communications interface415, one or more sensors420, and a user interface425. The controller400includes combinations of hardware and software that are operable to, for example, generate digital electricity, monitor for transmission fault conditions, etc. The controller400includes a plurality of electrical and electronic components that provide power and operational control to the components and modules within the controller400and/or the system100. For example, the controller400includes, among other things, a processing unit435(e.g., a microprocessor, a microcontroller, or another suitable programmable device), a memory440, input units445, and output units450. The processing unit435includes, among other things, a control unit455, an arithmetic logic unit (“ALU”)460, and a plurality of registers465(shown is a group of registers inFIG.4) and is implemented using a known architecture. The processing unit435, the memory440, the input units445, and the output units450, as well as the various modules connected to the controller400are connected by one or more control and/or data buses (e.g., common bus470). The control and/or data buses are shown schematically inFIG.4for illustrative purposes.

The memory440is a non-transitory computer readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as read-only memory (“ROM”), random access memory (“RAM”) (e.g., dynamic RAM [“DRAM”], synchronous DRAM [“SDRAM”], etc.), electrically erasable programmable read-only memory (“EEPROM”), flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, electronic memory devices, or other data structures. The processing unit435is connected to the memory440and executes software instructions that are capable of being stored in a RAM of the memory440(e.g., during execution), a ROM of the memory440(e.g., on a generally permanent basis), or another non-transitory computer readable data storage medium such as another memory or a disc. Software included in the implementation of the system100or controller400can be stored in the memory440of the controller400. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller400is configured to retrieve from memory and execute, among other things, instructions related to the control methods and processes describe herein. In some embodiments, the controller400includes a plurality of processing units435and/or a plurality of memories440for retrieving from memory and executing the instructions related to the control methods and processes describe herein.

In some embodiments, the controller400or network communications interface415includes one or more communications ports (e.g., Ethernet, serial advanced technology attachment [“SATA”], universal serial bus [“USB”], integrated drive electronics [“IDE”], etc.) for transferring, receiving, or storing data associated with the transmitter105or the operation of the transmitter105. In some embodiments, the communications interface415enables communication with an external network430for control and/or monitoring related to the system100. The network430is, for example, a wide area network (“WAN”) (e.g., a TCP/IP based network), a local area network (“LAN”), a neighborhood area network (“NAN”), a home area network (“HAN”), or personal area network (“PAN”) employing any of a variety of communications protocols, such as Wi-Fi, Bluetooth, ZigBee, etc. In some embodiments, the network430is a cellular network, such as, for example, a Global System for Mobile Communications (“GSM”) network, a General Packet Radio Service (“GPRS”) network, a Code Division Multiple Access (“CDMA”) network, an Evolution-Data Optimized (“EV-DO”) network, an Enhanced Data Rates for GSM Evolution (“EDGE”) network, a 3GSM network, a 4GSM network, a 4G LTE network, a 5G New Radio network, a Digital Enhanced Cordless Telecommunications (“DECT”) network, a Digital AMPS (“IS-136/TDMA”) network, or an Integrated Digital Enhanced Network (“iDEN”) network, etc.

The sensors420can include voltage sensors, current sensors, temperature sensors, etc. Output signals from the sensors420can be used by the controller400to determine various fault conditions of the transmitter105or the system100. In some embodiments, the fault conditions include cross-line fault conditions, in-line fault conditions, ground fault conditions, arc fault conditions, neutral fault conditions, etc.

The user interface425can include a combination of digital and analog input or output devices required to achieve a desired level of control and monitoring for the transmitter105. For example, the user interface425can include a display, one or more LEDs, and/or input devices such as a mouse, touch-screen display, a plurality of knobs, dials, switches, buttons, etc.

The power input module405is configured to receive input power from the source of AC power110and/or the source of DC power115. The power input module405is configured to supply nominal AC or DC voltages to the controller400or other components of the system100. The source of AC power110is, for example, mains power having nominal line voltages between 100V and 240V AC and frequencies of approximately 50-60 Hz. The source of DC power is, for example, a photovoltaic array or a battery bank (e.g., an array of battery cells having a lithium-based chemistry) capable of providing high DC voltages to the power input module (e.g., voltages between 12V DC and 1000V DC). The power input module405is configured to convert received AC power to DC power and/or step down received DC power to a lower voltage. In addition to powering the controller400, the power input module405is configured to provide power to the power output module410. In the embodiment illustrated inFIG.4, the transmitter105is capable of communicating with the receiver125through the communications interface415or using power line communication between the power output module410and the receiver125. With reference toFIG.2, the controller400can generally correspond to the source controller215and the power output module410can correspond to the switch220. The controller400is configured to generate digital electricity using energy transmission and sample periods as described above with respect toFIG.2.

FIG.5illustrates the first power distribution controller130ofFIG.1in more detail. The first power distribution controller130is electrically and/or communicatively connected to a variety of modules or components of the system100. For example, the first power distribution controller130is connected to the receiver125, the second power distribution controller135, and one or more of the devices140-170. The first power distribution controller130includes a controller500, a power input module505, a power output module510, a communications interface515, one or more sensors520, and a user interface525. The first power distribution controller130also includes an arc fault circuit interrupter (“AFCI”)530(e.g., switch220,225) for disabling power to the device140-170when an arc fault condition is detected.

The controller500includes combinations of hardware and software that are operable to, for example, receive and transform DC electricity, monitor for transmission fault conditions, etc. The controller500includes a plurality of electrical and electronic components that provide power and operational control to the components and modules within the controller500and/or the system100. For example, the controller500includes, among other things, a processing unit535(e.g., a microprocessor, a microcontroller, or another suitable programmable device), a memory540, input units545, and output units550. The processing unit535includes, among other things, a control unit555, an ALU560, and a plurality of registers565(shown is a group of registers inFIG.5) and is implemented using a known architecture. The processing unit535, the memory540, the input units545, and the output units550, as well as the various modules connected to the controller500are connected by one or more control and/or data buses (e.g., common bus570). The control and/or data buses are shown schematically inFIG.5for illustrative purposes.

The memory540is a non-transitory computer readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, electronic memory devices, or other data structures. The processing unit535is connected to the memory540and executes software instructions that are capable of being stored in a RAM of the memory540(e.g., during execution), a ROM of the memory540(e.g., on a generally permanent basis), or another non-transitory computer readable data storage medium such as another memory or a disc. Software included in the implementation of the system100or controller500can be stored in the memory540of the controller500. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller500is configured to retrieve from memory and execute, among other things, instructions related to the control methods and processes describe herein. In some embodiments, the controller500includes a plurality of processing units535and/or a plurality of memories540for retrieving from memory and executing the instructions related to the control methods and processes describe herein.

In some embodiments, the controller500or network communications interface515includes one or more communications ports (e.g., Ethernet, SATA, USB, IDE, etc.) for transferring, receiving, or storing data associated with the first power distribution controller130or the operation of the first power distribution controller130. In some embodiments, the communications interface515enables communication with the external network430for control and or monitoring related to the system100.

The sensors520can include voltage sensors, current sensors, temperature sensors, etc. Output signals from the sensors520can be used by the controller500to determine various fault conditions of the first power distribution controller130or the system100. In some embodiments, the fault conditions include cross-line fault conditions, in-line fault conditions, ground fault conditions, arc fault conditions, neutral fault conditions, etc.

The user interface525can include a combination of digital and analog input or output devices required to achieve a desired level of control and monitoring for the first power distribution controller130. For example, the user interface525can include a display, one or more LEDs, and/or input devices such as a mouse, touch-screen display, a plurality of knobs, dials, switches, buttons, etc.

The power input module505is configured to receive input power from the receiver125. The power input module505is configured to supply nominal DC voltages to the controller500or other components of the system100. The power input module505is configured, for example, step down received DC power to a lower voltage. In addition to powering the controller500, the power input module505is configured to provide power to the power output module510. In the embodiment illustrated inFIG.5, the first power distribution controller130is capable of communicating with the second power distribution controller135through the communications interface515or using power line communication between the power output module510and the second power distribution controller135. The power output module510is also configured to provide output power to one or more of the devices140-170. As described above with respect toFIG.3, the connection between the first power distribution controller130and the devices140-170can be configured as a POE implementation that enables the transmission of both power and data between the first power distribution controller130and the devices140-170.

The controller500is configured to provide arc fault protection to the system100. The controller500provides arc fault protection by detecting or determining the presence of an arc fault condition between the first power distribution controller130and one or more of the devices140-170. When the controller500detects or determines the presence of an arc fault condition, the controller500is configured to control the AFCI530to disable power to the affected device(s)140-170. In some embodiments, either the controller500or the device140-170can disable power distribution (e.g., by opening switch220,225) in the event of an arc fault condition.

The controller500is configured to detect an arc fault condition using a variety of techniques. In some embodiments, the controller500uses arc fault detection techniques individually. In other embodiments, the controller500implements a variety of arc fault detection techniques collectively. For example, the controller500can determine whether an arc fault condition is present based on the data portion of an energy packet and measuring an amount of error present in one or a series of energy packets (e.g., aggregate errors from unreceived data). Specifically, the controller500is configured to transmit a digital electricity energy packet (i.e., including an energy payload and a data payload) to a device140-170. The controller500is configured to determine or measure an amount of error associated with the digital electricity energy packet (e.g., associated with the data payload). In some embodiments, the controller500is configured to receive a determination or measurement of the amount of error associated with the digital electricity energy pack (e.g., from a device140-170). The controller500is then configured to evaluate the amount of individual or accumulated errors for a given data packet or a series of data packets (e.g., data packets received over a predetermined period of time). Errors specific to a data packet include, for example, a loss of data in the data packet (e.g., evaluated based on frame loss rate), an amount of attenuation of the data packet (e.g., a magnitude of the reduction in the amplitude of the transmitted data), an amount of distortion associated with the data signal (e.g., signal-to-noise ratio), etc.

When the controller500determines that an individual error or aggregate of errors associated with a data packet or series of data packets is greater than or equal to an error threshold value (e.g., a frame loss rate threshold value, an attenuation threshold value, a signal-to-noise ratio threshold value, etc.), the controller500determines that an arc fault condition is present. In some embodiments, the controller500is configured to determine whether other fault conditions associated with the system100are present, such as an improper connection, a loose connection, excessive cable length, external noise, etc. (e.g., based on the amount of error present). When the controller500determines that an arc fault condition or other fault condition is present, the controller500is configured to disable power to, for example, one or more of the devices140-170. In some embodiments, when the controller500determines that an arc fault condition or other fault condition is present, the controller500is configured to disable a power connection to the receiver125or the second power distribution controller135. In some embodiments, the controller500is configured to transmit a data packet and evaluate the transmitted data packet to take a protective action based on the transmitted data packet. For example, the controller500can evaluate the transmitted data packet to self-identify or self-diagnose arcing or an error in a wiring system, a fault in a data packet transmission system, a fault in an energy conversion or control system, etc.

Additionally or alternatively, the controller500uses a predetermined data packet or diagnostic signal between the first power distribution controller130and the devices140-170to detect an arc fault condition. For example, similar to the error-based fault detection described above, the controller500is configured to evaluate accumulated errors for the predetermined data or diagnostic signal(s). Errors specific to such a signal include, for example, a loss of data in the data packet (e.g., evaluated based on frame loss rate), an amount of attenuation of the data packet (e.g., a magnitude of the reduction in the amplitude of the signal), an amount of distortion associated with the signal (e.g., signal-to-noise ratio, etc.), etc. When an individual error or aggregate of errors (e.g., based on percentage correlation of the received data packet and the predetermined data packet) associated with signal is greater than or equal to an error threshold value (e.g., a frame loss rate threshold value, an attenuation threshold value, a signal-to-noise ratio threshold value, an error percentage, etc.), the controller500determines that an arc fault or other fault condition is present. In some embodiments, evaluating a diagnostic signal provides more precise fault detection because the diagnostic signal being evaluated is a predetermined packet having a reference value known by the controller500.

In some embodiments, arc fault detection is focused on individual devices (e.g., network address-based arc fault detection). For example, the controller500can vary one or more thresholds for detecting arc fault conditions. Devices that are more likely to produce an arc fault condition can be monitored more closely. In some embodiments, devices that use more than a threshold level of power (e.g., more than 250 W) are monitored for arc fault conditions, and devices that use the threshold level or less of power are not monitored for arc fault conditions.

In some embodiments, and with reference toFIG.2, the controller500can generally correspond to the source controller215and the power output module510can correspond to the switch220. In such embodiments, the controller500is configured to generate digital electricity using energy transmission and sample periods as described above with respect toFIG.2. In some embodiments, the second power distribution controller135is configured to operate in the same or similar manner as the first power distribution controller130.

The arc fault protection techniques describe above with respect to the first power distribution controller130apply equally to the operation of the second power distribution controller135. In some embodiments, the arc fault protection techniques described above are applied at other locations within the system100, such as between the power sources110,115and the transmitter105, between the transmitter105and the receiver125, and between the receiver125and the first power distribution controller130.

Thus, embodiments described herein provide, among other things, arc fault protection in a digital electricity power distribution system. Various features and advantages are set forth in the following claims.