Apparatus and method for improved switchgear sensor data communication

Abstract

Devices, systems, and methods are provided for improving switch sensor and status signal communication between a medium voltage overhead switchgear and an intelligent electronic device (IED). The switchgear interface device is disposed near a switchgear and / or junction box located at the distal end of the pole. A switchgear interface device (SID) receives, processes and combines sensor signals and status signals from switches in the switchgear with metadata for transmission as digital signals to an IED mounted at the other end of the telegraph pole. The routing of the sensors and status signals between the SID and the IED may be fiber optic or Ethernet. The digital signal may be formatted by using the IEC61850 standard. The SID may have driving electronics and send open and close command signals to the switch to eliminate the need for a multi-pin connector cable for transmitting switching power signals from the IED.

Description

Technical Field

[0001] Exemplary embodiments generally relate to apparatus and methods for improved communication of data related to sensing of voltage, current, and other status conditions at a switchgear switch (e.g., a switchgear switch deployed on medium voltage overhead switchgear) and processing and combining of sensor data at the switchgear switch or at a junction box on a utility pole. Exemplary embodiments also generally relate to apparatus and methods for simplified and more reliable communication of sensor data and status signals between a switchgear and remote switchgear controllers and other distribution controllers and monitoring devices with less loss and higher accuracy. Background Art

[0002] An automatic circuit recloser is a class of distribution switchgear primarily designed for use on overhead distribution circuits to detect and interrupt fault current. These switchgears are essentially high voltage circuit breakers with two main functions: 1) sensing current and voltage on a circuit (e.g., a phase conductor); and 2) interrupting load and / or fault current. A switchgear switch is provided on each phase conductor of the switchgear. The switchgear switch can be opened and closed quickly and temporarily (e.g., until a temporary fault condition is cleared), or opened indefinitely (e.g., when an unwanted load or fault condition is not temporary and maintenance of the phase conductor is required).

[0003] The switchgear switch can be operated automatically via a controller or manually. Most commercially available recloser switchgears operate based on vacuum interruption, solid dielectric insulation, and magnetic actuation technologies. The switchgear switch also has current and voltage sensors on its corresponding phase conductor. The embedded current sensor in the switchgear switch is typically a bushing current transformer (CT), and the embedded voltage sensor is a resistive or capacitive voltage divider for the line or source side. The switchgear switch circuit can also optionally have additional voltage sensors for the load side.

[0004] Figures 1A and 1B depict a typical recloser switchgear located at the distal end of a utility pole and a cabinet with a controller located at the proximal end of the utility pole for ease of maintenance operations at ground level. Cables connect each of the recloser switchgear switches or three switchgear switches provided to corresponding phase conductors of three phase conductors in a three-phase recloser to the controller cabinet and correspondingly to controller components therein. As described in more detail below, the cables have conductors for, e.g., transmitting sensor data from the switchgear sensors on each phase conductor to the controller, conductors for providing open-to-close switch power signals and close-to-open switch power signals from the controller to the switchgear switches on each phase conductor, and other conductors for switch status and optional DC power. Summary of the Invention

[0005] By way of illustrative embodiments, the above and other problems are overcome and additional advantages are realized.

[0006] According to an illustrative embodiment, a method for communication between a medium voltage overhead switchgear and an intelligent electronic device (IED) is provided. The switchgear is installed at a distal end of a utility pole and connected to a distribution line, and the utility pole has a proximal end fixed to a ground support. The IED is fixed at the proximal end. The switchgear has sensors at a switch disposed at one of three phase conductors associated with the distribution line. The method includes: receiving an analog signal providing a representation of current and voltage measured by the sensors at the switch, and at least one status signal indicating one of an open state and a closed state of the switch; digitizing the analog signal to thereby generate a corresponding digital input; sampling the digital input; combining the samples into a set of combined digital samples having a specified format and including a digital representation of current or voltage in the corresponding one of the phase conductors measured by the sensors, the status signal, and metadata selected from at least one of an identifier of the sensor from which the corresponding digital sample in the digital samples is derived, an identifier of the switch, an identifier of the switchgear, and location data; performing the receiving, digitizing, sampling, and combining via one or more components at a switchgear interface device located near the switch and at the distal end of the utility pole; and providing the combined digital samples and metadata as an output to a digital data connector located at the switchgear interface device and configured to be connected to a digital data cable.

[0007] According to aspects of an illustrative embodiment, the method further includes connecting a digital data cable between the digital data connector and the IED, the digital data cable selected from an optical fiber cable and an Ethernet cable, and the digital data connector selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the digital data cable.

[0008] According to aspects of an illustrative embodiment, the combining includes formatting the combined digital samples using the IEC61850 standard from the International Electrotechnical Commission (IEC).

[0009] According to aspects of an illustrative embodiment, the combining includes: formatting the combined digital samples using the IEC61850-9-2 protocol from the IEC, the combined digital samples being encoded in a multicast Ethernet frame; and transmitting the unacknowledged data of the combined digital samples from the switchgear interface device operating as a publisher to subscribers including the IED according to the IEC61850-9-2 protocol.

[0010] According to aspects of an illustrative embodiment, the combining further includes providing Global Positioning System (GPS) time synchronization to the combined digital samples.

[0011] According to an illustrative embodiment, a switchgear interface device is provided. The switchgear interface device can be used, for example, to be mounted on a distal end of a utility pole and connected to a medium voltage overhead switchgear of a distribution line. The utility pole has a proximal end fixed to a ground support and a cabinet with a smart electronic device (IED) fixed at the proximal end. The switchgear has sensors at a switch disposed at one of three phase conductors associated with the distribution line. According to an illustrative embodiment, an example switchgear interface device includes: a housing configured to be arranged adjacent to the switchgear and mounted on the distal end of the utility pole; a plurality of inputs at the housing configured to receive an analog signal providing a representation of a current or voltage measured by a sensor at the switch and to receive at least one status signal indicating one of an open and a closed state of the switch; a processor; a memory; and a digital data connector. The processor is arranged within the housing and configured to digitize the analog signal and the at least one status signal to thereby generate corresponding digital inputs, sample the digital inputs, and combine the samples into a set of merged digital samples having a specified format and including a digital representation of a current or voltage of a corresponding one of the phase conductors measured by the sensor, the status signal, and metadata. The metadata is selected from at least one of an identification of the sensor from which the corresponding digital sample in the digital samples is derived, an identification of the switch, an identification of the switchgear, and location data. The memory is arranged within the housing and configured to store the set of merged digital samples. The digital data connector is connected to the housing and configured to connect to a digital data cable selected from an optical fiber cable and an Ethernet cable and to provide the merged digital samples and the metadata as an output to the digital data cable and the IED when the digital data cable connects the digital data connector and the IED, the digital data connector being selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the digital data cable.

[0012] According to aspects of an illustrative embodiment, the switchgear interface device further includes drive electronics and an energy storage device for powering the drive electronics. The processor is configured to receive a switch command signal transmitted via the digital data cable from the IED at the digital data connector and to operate the drive electronics to send a switching power signal to the switch to open or close according to the switch command signal.

[0013] According to aspects of the illustrative embodiments, the switchgear interface device further includes a switched power signal connector that is connected to the housing and is configured to connect to a second cable separate from the digital data cable and to receive, via the second cable, switched power signals for the switch, including close-to-open signals and open-to-close signals, from an IED when the second cable connects the switched power signal connector and the IED. The switched power signal connector includes at least one of pins and sockets that receive corresponding ones of the switched power signals and provide them to a terminal block electrically connected in the housing to a switch actuation mechanism in the switch.

[0014] According to aspects of the illustrative embodiments, the switchgear interface device uses the IEC61850 standard from the International Electrotechnical Commission (IEC) as the specified format.

[0015] According to aspects of the illustrative embodiments, the processor of the switchgear interface device is configured to employ the IEC61850-9-2 protocol from the IEC, where the processor operates as a publisher and transmits unacknowledged data to subscribers including the IED, and the unacknowledged data includes merged digital samples encoded in a multicast Ethernet frame.

[0016] According to aspects of the illustrative embodiments, the processor of the switchgear interface device is configured to employ Global Positioning System (GPS) time synchronization of the merged digital samples.

[0017] According to aspects of the illustrative embodiments, the switchgear has a second switch and a third switch respectively disposed at the other two of the three phase conductors. A plurality of inputs at the housing of the switchgear interface device are configured to receive analog signals providing representations of current or voltage measured by sensors disposed at each of the second switch and the third switch, and to receive status signals indicating one of the open and closed states of the second switch and the third switch. The processor of the switchgear interface device is configured to digitize the analog signals and status signals from the second switch and the third switch to thereby generate corresponding digital inputs, sample the digital inputs, and combine the samples into a set of merged digital samples having a specified format such that the set of merged digital samples generated by the processor also includes digital representations of the current and voltage of the other two of the phase conductors measured by their corresponding sensors, status signals of each of the switches at the other two of the phase conductors, and metadata corresponding to the second switch, the third switch, and the sensors of the other two of the phase conductors.

[0018] According to an illustrative embodiment, a switchgear interface device is provided. The switchgear interface device can be used, for example, for a medium voltage overhead switchgear mounted on a distal end of a utility pole and connected to a distribution line, the utility pole having a proximal end fixed to a ground support and a cabinet with a smart electronic device (IED) fixed at the proximal end. The switchgear has a sensor at a switch disposed at one of three phase conductors associated with the distribution line. The switchgear is disposed adjacent to a junction box at the distal end of the utility pole. The switchgear interface device (SID) includes a switch SID assembly disposed near the switch and electrically connected to the switch. The switch SID assembly includes: a processor configured to receive an analog signal from the sensor being a representation of a current or voltage measured by the sensor at the switch, and at least one status signal indicating one of an open state and a closed state of the switch. The processor is configured to digitize the analog signal and the at least one status signal to thereby generate corresponding digital outputs, sample the digital outputs, and combine the samples into a set of merged digital samples having a specified format and including a digital representation of a current or voltage of a corresponding one of the phase conductors measured by the sensor, the status signal, and metadata. The metadata is selected from at least one of an identification of the sensor from which the corresponding digital sample in the digital samples in the sensor is derived, an identification of the switch, an identification of the switchgear, and location data. The switch SID assembly further includes: a memory configured to store the set of merged digital samples; and a digital data connector configured to connect to a digital data cable selected from an optical fiber cable and an Ethernet cable, and provide the merged digital samples and the metadata to the junction box when the digital data cable connects the digital data connector and the junction box. The digital data connector is selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the digital data cable.

[0019] In accordance with aspects of an illustrative embodiment, the switchgear interface device further includes: a second digital data connector mounted on the junction box and configured to connect to a digital data cable and receive combined digital samples and metadata from the switch SID assembly when the digital data cable connects the digital data connector and the second digital data connector on the junction box; a third digital data connector connected to the junction box and configured to connect to a second digital data cable selected from an optical fiber cable and an Ethernet cable and provide the combined digital samples and metadata as an output to the second digital data cable and the IED when the second digital data cable connects the third digital data connector and the IED. The third digital data connector is selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the second digital data cable. A communication hub is disposed in the junction box and has a plurality of ports and is configured to provide a signal received at one of the ports to one or more of the other ports of the plurality of ports, and the second digital data connector and the third digital data connector are connected to corresponding ports of two of the plurality of ports. The communication hub is operable to provide the combined digital samples and metadata received at the second digital data connector to the third digital data connector.

[0020] In accordance with aspects of an illustrative embodiment, the switchgear interface device further includes: drive electronics in the junction box and an energy storage device in the junction box that powers the drive electronics; and a multi-pin connector at each of the junction box and the switch where a switch power signal cable separate from the digital data cable is connected through an interface. The multi-pin connector at the switch is electrically connected to the actuating mechanism of the switch, and the multi-pin connector at the junction box is electrically connected to the drive electronics. A processor is configured to receive a switch command signal transmitted from the IED via the communication hub, the second digital data cable, and the digital data cable at the digital data connector, and send a control signal via the digital signal cable to the drive electronics to operate the drive electronics to send a switch power signal to the switch to open or close according to the switch command signal. The switch power signal cable transmits the switch power signal to the switch.

[0021] In accordance with aspects of an illustrative embodiment, the switchgear interface device uses the IEC61850 standard from the International Electrotechnical Commission (IEC) as the designated format.

[0022] In accordance with aspects of an illustrative embodiment, the processor of the switchgear interface device is configured to adopt the IEC61850-9-2 protocol from the IEC, where the processor operates as a publisher and transmits unacknowledged data to subscribers including the IED, and the unacknowledged data includes combined digital samples encoded in a multicast Ethernet frame.

[0023] According to aspects of the illustrative embodiments, the switchgear interface device is configured to employ Global Positioning System (GPS) time synchronization that combines digital samples.

[0024] According to aspects of the illustrative embodiments, the switchgear includes a second switch disposed at two of the three phase conductors, and the switchgear interface device further includes a second electronic circuit disposed near the second switch. The second switch signal conditioning circuit includes: a second processor configured to receive an analog signal that is representative of a current or voltage measured by a sensor at the second switch, and at least one status signal indicating one of an open state and a closed state of the second switch, digitize the at least one status signal and the analog signal corresponding to the second switch to thereby generate corresponding digital outputs, sample the digital outputs of the second switch; and a second memory configured to store samples of the second switch.

[0025] According to aspects of the illustrative embodiments, the processor of the switchgear interface device includes a data conversion and combination device configured to: combine the stored samples from the second switch into a second combined digital sample having a specified format and including digital representations of the current and voltage measured at the second switch, at least one status signal corresponding to the second switch, and second metadata selected from at least one of an identification of the sensor from which the corresponding sample in the digital sample from the second set of sensors is derived, an identification of the second switch, and identification and location data of the switchgear. The data conversion and combination device is configured to combine the one combined digital sample and the second combined digital sample and provide them to the junction box via a digital data connector.

[0026] Additional and / or other aspects and advantages of the illustrative embodiments will be set forth in the following description, or will become apparent from the description, or may be learned by practice of the illustrative embodiments. The illustrative embodiments may include a switchgear interface device and a method of operating the same having one or more of the above aspects and / or one or more of its features and combinations. The illustrative embodiments may include, for example, one or more of the features and / or combinations of the above aspects recited in the appended claims. Description of the Drawings

[0027] Aspects and advantages of the illustrative embodiments are more readily understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0028] FIGS. 1A and 1B depict a front view and a side view, respectively, of an example conventional switchgear mounted on a utility pole and connected to a conventional control cabinet via a junction box and conventional cables;

[0029] Figures 1C and 1D respectively depict a rear view and a front view of an exemplary conventional three-phase switchgear having three switches mounted in a single base housing, and Figure 1E is a perspective view of the switch and the base housing mounted on a utility pole;

[0030] Figures 1F and 1G respectively depict a rear view and a front view of three exemplary conventional single-phase switchgears each having a switch with a dedicated base housing, and Figure 1H is a perspective view of the three single-phase switchgears mounted on a utility pole;

[0031] Figures 2A and 2B are respectively a perspective view and a side view of an exemplary switchgear and its associated components;

[0032] Figure 3A depicts a cross-section of a connector of a conventional cable deployed between a junction box and a control cabinet in the arrangement shown in Figure 1A;

[0033] Figure 3B depicts a partial side view of a wire in a conventional cable deployed in the arrangement shown in Figure 1A;

[0034] Figure 4 is a block diagram of components in a switchgear, a junction box, and a control cabinet interface in the arrangement shown in Figure 1A;

[0035] Figure 5 is a block diagram of components of an improved switchgear interface device according to an illustrative embodiment;

[0036] Figure 6A is a block diagram of components of an improved switchgear interface device arranged in a junction box to deploy improved cabling to a control cabinet according to an illustrative embodiment;

[0037] Figure 6B is a block diagram of components of an improved switchgear interface device arranged in a junction box and having drive electronics to deploy improved cabling to a control cabinet according to another illustrative embodiment;

[0038] Figure 7A is a block diagram of components of an improved switchgear interface device arranged at a switch of a switchgear and in a junction box to deploy improved cabling to a control cabinet according to yet another illustrative embodiment;

[0039] Figure 7B is a block diagram of components of an improved switchgear interface device arranged at a switch of a switchgear and in a junction box having drive electronics to deploy improved cabling to a control cabinet according to still another illustrative embodiment;

[0040] Throughout the drawings, like reference numerals will be understood to refer to like elements, features, and structures. Detailed Description

[0041] Reference is now made in detail to the illustrative embodiments depicted in the accompanying drawings. The embodiments described herein are illustrated by reference to the drawings and are not intended to limit the illustrative embodiments.

[0042] Example embodiments of the present disclosure provide technical solutions to several technical problems that will now be described.

[0043] Utility sectors are generally satisfied with the high current interruption and dielectric performance of switchgear. However, the sensing performance of this type of switchgear is an area where most stakeholders (e.g., utility sectors, maintenance and monitoring suppliers and contractors, and utility customers) are dissatisfied. For example, most reclosers currently commercially available provide an accuracy range of ±1 - 2% in the load current range (e.g., about 630 - 800 A) and an accuracy range of ±2 - 4% in voltage sensing. In addition, the fault current accuracy is generally not published by recloser manufacturers and tends to be lower, i.e., in a larger range greater than ±3 - 5%.

[0044] In addition to the accuracy of the sensor data received from the switchgear being at an unsatisfactory level, other aspects such as linearity, accuracy, and high - order harmonic response are also below the requirements and expectations of customers. For example, as utility sectors attempt to address more complex problems in the distribution network, reclosers serve as key assets on the utility distribution system, and thus utility sectors expect these devices to have more functions and performance. Some examples of such complex problems are (a) power quality issues due to the increasing growth of inverter - based generation, and (b) deficiencies or lack of high - impedance fault detection, open - wire detection, open - neutral detection, and / or sectionalization and coordination of reclosers. In order to reduce the number of customers affected by a particular service interruption, it is particularly necessary to address the above - mentioned (b) problems in shorter feeders with a large number of customers.

[0045] According to aspects of example embodiments of the present disclosure, the existing sub - standard performance in current and voltage sensing of switchgear is addressed, and thus, compared with existing switchgear and controller systems, a fundamentally different architecture for switchgear signal access and communication is used to improve the drawbacks in related applications of the distribution system. For ease of discussion, example switchgear 12 and controller 20 are shown in FIGS. 1A and 1B. Switchgear 12 can be, for example, LIBERTY available from Hubbell Incorporated, Shelton, Connecticut, USA TMThe HB series pole-mounted three-phase interlocking reclosers, or the Viper ST, etc. commercially available from G&W Electric Company, Bolingbrook, Illinois, USA. The controller or intelligent electronic device (IED) 20 can be, for example, the SEL-651-2 recloser control commercially available from Schweitzer Engineering Laboratories, Inc., Pullman, Washington, USA, or the M-7879 type R-PAC protection, automation, and control system commercially available from Beckwith Electric Company, Largo, Florida, USA, or as described in the commonly assigned US Published Patent Application No. 2021 / 0234360, the entire content of which is incorporated herein by reference. It should be understood that different switchgear 12 and controllers 20 can be used. As shown in FIGS. 1C-1E, an example switchgear 12 can be a conventional three-phase switchgear having three switches 28a-c mounted in a single base housing 30. FIGS. 1F-1H depict three example conventional single-phase switchgears 12a-c, each single-phase switchgear having a switch 28a-c with a dedicated base housing 30a-c. FIGS. 1E and 1H show the switchgear 12 mounted to the utility pole 10 using the mounting bracket 14, as well as the junction box 16 and the potential transformer 36 also fixed to the mounting bracket. The junction box 16 can alternatively be mounted directly to the utility pole. One or more cables 24 connect the switchgear 12 to the junction box 16. For clarity, only one cable 24 from the switchgear 12 to the junction box 16 is shown in FIGS. 1A and 1B. The front of the example switchgear 12 shown in FIGS. 1D and 1G has access panels 34a-c for the respective switches 28a-c, the access panel having connectors for the cables and other electronic components such as visual indicators 48 (FIG. 2A) for the switch status. The back of each switchgear 12 shown in FIGS. 1C and 1F has manual trip handles 32a-c for the corresponding switches 28a-c. In a conventional recloser 12, the junction box 16 is typically an enclosure that serves as a common junction point for the wires from the recloser switch 28, where the wires are connected before moving onto the recloser controller IED 20 in a single multi-pin cable assembly 26.

[0046] Referring to FIGS. 2A and 2B, an example recloser switchgear 12 is shown. For clarity, phase conductors and the lines connecting the phase conductors to the respective switches 28a - c are omitted, and for clarity, the lines between the controller 20 or junction box 16 and the switches 28a - c (e.g., for switch actuation or status indication) are also omitted. Each switch 28 connected to a corresponding phase conductor has a vacuum circuit breaker 40, a drive assembly 42, and a magnetic actuator 44, which are operated (e.g., via signals from the IED 20) to open from a closed position or close from an open position relative to its phase conductor. The switch 28 can also be operated by a manual trip handle 46, and an optional position indicator 48 can be provided. As described above, the switchgear switches 28 respectively have current sensors 38a for monitoring the corresponding phase conductors and at least one voltage sensor 38b. The recloser switchgear 12 typically includes bushing current transformers (CTs) 38a with a ratio of 1000:1 or 500:1 and one or more voltage sensors 38b, 38c in the range of 10000:1 to 2000:1 ratio. Thus, the sensor signals generated by the switchgear 12 are typically on the order of a few amperes (a) or a few volts (V). For example, on a 7200V line carrying a 100A load current per phase, the output of the sensors can be 0.72V and 1A. As described below, in the existing configuration of the switchgear 12 on the pole 10 that results in unsatisfactory accuracy, these signals suffer significant signal loss.

[0047] Continuing to refer to FIGS. 1A and 1B, these overhead reclosers 12 are typically installed on the pole 10 at a height of 40 - 50 feet above the ground and are connected to an intelligent electronic device (IED) or recloser controller 20 in the control cabinet 18, which is installed closer to the ground (e.g., at 3 - 6 feet above the ground at the pole 10) for technicians to access to replace the controller 20 battery and perform operations such as configuration and calibration. The single - phase recloser switch 12 is connected by wires to a common junction box 16, which is installed on the mounting bracket 14 of the switchgear 12 or is installed on the pole 10 near the switchgear 12. Then, cables 26 are used to connect the elevated junction box to the controller cabinet accessible from the ground.

[0048] Figure 4 depicts example components in a conventional switchgear 12, junction box 16, and control cabinet 18. Three switches 28a - c of an example recloser switchgear 12 are shown, where each switch 28 has a switch activation mechanism 44 for phase conductors, a circuit breaker 40, current and voltage sensors 38a - c, and a switch status indicator 50. A voltage transformer 36 is also shown. The switches 28a - c are connected to the junction box 16 via power, status, and sensor cables 24 typically on the order of 3 - 5 feet in length. The switchgear 12 and the junction box 16 each have corresponding connectors (e.g., an 8 - pin count multi - pin connector 68). The junction box includes a terminal block 60 having multi - pin connectors 68, 70, and other electrical connections to provide switch power signals from the IED 20 to the corresponding recloser switch cable connectors 68a - c, and to provide sensor signals and status signals from the switches 28a - c to the IED 20. In the control cabinet 18, the IED 20 typically includes, for example, a main control board 62a, an analog - to - digital sensor board 62b, and a communication board 62c. The power and drive electronics 64 can include, for example, drive electronics 64a and an energy storage device 64b powered from a power source such as a battery disposed in the cabinet, such as a capacitor. The battery provides power to other cabinet components and can be charged from a DC power signal obtained through the voltage transformer on the switchgear. The power and drive electronics 64 can also include an optional automatic transfer switch 64c. The remote communication device 66 can include, for example, a wireless communication device 66a, such as a cellular transceiver or a radio transceiver. A security gateway 66b can be provided when the IED 20 transmits switchgear status and operation information to a remote device such as a utility distribution management control station. Other miscellaneous components 66c, such as cabinet heaters, can be disposed in the controller cabinet. A power cable 72 on the order of 40 - 50 feet connects the voltage transformer to the control cabinet to provide power thereto. As described below in connection with FIGS. 3A and 3B, a high - pin count multi - pin connector 70 is disposed on the IED side of the junction box 16 to connect to the control cabinet 18 using a high - pin count multi - pin cable 26.

[0049] Therefore, the length of the existing cables 26 used to connect the junction box 16 and the control cabinet 18 is typically 40 to 50 feet and is very complex and expensive. Each of these cables 26 includes cable assemblies with different pin count ranges, varying from 14-pin to 42-pin connection interfaces, and has various conductors for carrying several different types of signals, such as low-voltage or low-ampere sensor data, high-power on / off switch power signals, and switch status signals between the recloser switching device and the controller devices (such as IEDs) in the control cabinet. When sending sensitive voltage or current sensor signals (e.g., as described above, on the order of <1V and 1A) from the switching device 12 via one of these 40 - 50 foot cable 26 assemblies, each cable 26 assembly causes loss of amplitude accuracy, loss of phase accuracy, and induced noise due to signal interference and grounding problems.

[0050] Now, the reasons for these losses in the conventional cable 26 and other drawbacks of the conventional cable 26 are described with reference to FIGS. 3A and 3B. In FIG. 3A, an example 32-pin connection interface 52 is shown for an example cable 26. FIG. 3B is a partial side view of the cable 26 assembly, where the outer sheath is removed and the wire bundle 54 1～4 is partially disassembled for better viewing of the various wiring and shielding components within the cable assembly. Generally, the conventional cable 26 between the switching device 12 and the control cabinet 18 includes different wire bundles 54 1～4 , including: a first and / or second wire bundle 54 1～2 carrying voltage signals from the voltage sensors 38b, 38c at the corresponding phase conductors of a single-phase or three-phase distribution line; a third wire bundle 543 carrying current signals from the current transformers 38a in each of the recloser switching device switches 28a - c connected to the corresponding phase conductors and the switch device switch status signals; and a fourth wire bundle 544 carrying open-to-close and close-to-open command signals for each of the switches 28a - c. As shown in FIG. 3A, the cable connector 52 has a plurality of pin sockets for the corresponding voltage sensor signal wires (e.g., one or two such wires for each switch device switch disposed on the phase conductor), current sensor signal wires (e.g., at least one wire for each switch device switch), switch status signal wires, and a pair of open-to-close and close-to-open switch power signal wires for each switch device switch. Since charge accumulates across the insulation between the cable wires as the wires carry voltage signals over time, the conventional cable 26 carrying sensor data or signals is affected by the inherent capacitance. This capacitance causes delays and interference in signal transmission.

[0051] The conventional cable 26 is configured to minimize unwanted capacitive coupling between the components of the cable 26 by using a variety of different methods. For example, the load and source voltage signal conductors are separated, and a ground conductor (not shown) that contacts all of these conductors and is connected end-to-end in the cable assembly is added. Support conductors are provided to increase the stiffness of the heavy cable to reduce strain on the wire bundle. A shield (e.g., aluminum foil 56) can be provided on the separate load and source voltage bundles and connected to a drain wire 58 that is connected end-to-end in the cable 26 assembly.

[0052] As shown in FIGS. 3A and 3B, the design of the conventional cable 26 is complex due to the number of wires extending between the switchgear 12 and the control cabinet 16, the capacitive coupling mitigation materials and configurations, and the complex multi-pin connectors 70 used to interface the wires to the control cabinet and the junction box 16; thus, the cable 26 is expensive. Other drawbacks are that even with shielding, the signals transmitted along the cable 26 still need to be calibrated with a factor that corrects for the inherent capacitance. This calibration requires the use of high-precision voltage dividers and high-potential (Hipot) electrical safety testers and the length of the cable 26 used in a particular application (i.e., for the ratio correction factor (RCF)). In addition, as the length increases, these conventional cables 26 also introduce an increasing unwanted phase shift in the sensor signal data, which causes the sensor signal data to become more inaccurate as it is transmitted along the cable 26. The utility also has to take into account that the considerable weight of these complex conventional cables 26 causes a predicted shortening of the life of the junction box 16 and / or the control cabinet 18 interfaced with the cable 26 due to torque, and thus, increased wear on the wires and connectors of the cabinet 18 or the junction box 16 originating from the cable weight. To assist in the installation and fixation of the conventional cable 26, the cable connectors 52, 70 can have twist-lock features. The multi-pin connector 52 also needs to be properly potted (e.g., back potted with a selected resin filling material) to hold all 14 - 42 or more wires in place. The back-potting process of the cable connector 52 itself is a complex process. Thus, the cable connector 52 for such a complex multi-wire cable 26 adds to the complexity and cost of the conventional cable 26 for recloser controller connections and requires special handling, which further complicates the installation of the conventional cable 26 in the field.

[0053] Example embodiments of the present disclosure provide a switchgear interface device (SID) 80 and a method of using the same that improves the quality of sensor data from a recloser switchgear 12 to a recloser controller IED 20. As described below, the SIDs 80 according to example embodiments each have an architecture that allows sensor data and other signals (e.g., status signals) to be digitized near the source (e.g., switchgear switch sensor), which significantly reduces the loss and noise introduced into the sensor data by conventional cables. These SIDs 80 also allow cheaper, simpler cables to be used between the switchgear 12 and the control cabinet 18.

[0054] Thus, when the SID 80 is deployed at the switchgear 12 on the utility pole 10 in accordance with the example embodiment, significant advantages are realized through the SID 80 data connection to the switchgear controller 20, which does not introduce losses and does not otherwise degrade the integrity of the sensor data received from the switchgear switch sensors 28a-c, as compared to the conventional multi-pin cable 26 described above in conjunction with Figures 3A and 3B. In addition, since the reduced pin count multi-pin cable 92 only needs to carry six conductors, namely a pair of conductors for transmitting the open to closed switch power signal and the closed to open switch power signal for each of the switches 28a-c at the phase conductors, respectively, the SID 80 is connected to the switchgear controller 20 via a much simpler, cheaper and reduced pin count multi-pin cable 92 as compared to the conventional 14-42 pin count multi-pin cable 26 described above in conjunction with Figures 3A and 3B. Therefore, the reduced pin count multi-pin cable 92 is less complex and less expensive than the conventional 14-42 pin count multi-pin cable 26 described above. As described below in conjunction with Figure 6B and Figure 7B As described, example embodiments of the SID 80 eliminate the need to use a lower pin count multi-pin cable 92 between the SID 80 and the control cabinet 18 .

[0055] Reference is now made to FIG. 8 which is a block diagram of example components of a SID 80 configured in accordance with an illustrative embodiment. Figure 5 The SID 80 is connected between the switch device 12 and the controller 20 . Figure 5Also depicted are some components of the switchgear 12, such as the recloser switches 28a - c for three phase conductors and the potential transformer 36, as well as the recloser control cabinet 18. As described above in connection with FIGS. 2A, 2B, and 4, the recloser switches 28a - c respectively have, for example, an actuator mechanism 44 and a circuit breaker 40, sensors 38 (such as current sensors 38a, voltage sensors 38b, 38c), and a switch status indicator 50. An exemplary recloser control cabinet 18 has recloser control IEDs 20, 62, power and drive electronics 64 for generating a switched power signal for controlling the opening / tripping or closing of the switchgear switches, and a remote communication device 66. The IED 62 can include, for example, a main control board 62a and a communication board 62c, but an analog - to - digital sensor board 62b is not required in the IED 62. The power and drive electronics 64 can include, for example, drive electronics 64a and an energy storage device, such as a capacitor, powered from a power source 64b such as a battery disposed in the cabinet. The battery provides power to other cabinet components and can be charged from a DC power signal obtained through the potential transformer on the switchgear. The power and drive electronics 64 can also include an optional automatic transfer switch 64c. The remote communication device 66 can include, for example, a wireless communication device 66a, such as a cellular transceiver or a radio transceiver. A security gateway 66b can be provided when the IED transmits switchgear status and operation information to a remote device such as a utility distribution management control station. Other miscellaneous components 66c, such as cabinet heaters, can be disposed in the controller cabinet 18. As described below in connection with Figure 6A and Figure 7A For example, according to an exemplary embodiment, the SID 80 can have different configurations regarding how its components are connected to the switchgear switches 28a - c. However, in various embodiments, the SID generally includes a terminal block 88 or other connection hardware to wires extending between the switchgear switches 28a - c and a junction box 16 or other enclosures near the switchgear mounted at the distal end of the utility pole 10. The SID 80 generally also includes an analog - to - digital converter 82 for switchgear switch sensor data and switch status signals, a main processor and memory 84, and a data conversion and combination device 86 to format and combine digital samples of the sensor data signals and switch status signals according to a specified format or protocol such as IEC61850 - 9 - 2. The terminal block 88 and / or the junction box 16 enclosure also includes hardware connectors to provide signals from the data conversion and combination device 86 to a digital data cable 90 extending from the SID 80 to the controller 20 and / or the control cabinet 18 mounted on the ground at the proximal end of the utility pole 10.

[0056] Referring to Figure 6A, the SID 80 is implemented such that its components are located in a junction box 16 installed near the switchgear 12 at the distal end of the utility pole 10, thus at a certain distance from the control cabinet 18 at the opposite end of the utility pole 10, close to the ground and accessible to technicians. The SID 80 includes a digital data connector 91 for connection to a digital data cable 90 (e.g., an optical fiber or Ethernet cable), and a terminal block 94 having a multi-pin cable connector 89 with a reduced pin count (e.g., 8 pins) for connection to a multi-pin cable 92 with a reduced pin count (e.g., 8 pins) that extends between the junction box 16 and the controller 20 and transmits switch power signals to open or close each switch 28a - c. The SID 80 also includes a switch-side connector 68 (e.g., an 8-pin count multi-pin cable connector) for connection to a power, status, and sensor cable 24 that extends between the junction box 16 and the sensors and actuators of the switch 28 at a corresponding one of the phase conductors. For clarity, the switch of phase A conductor is shown, and the switches of phase B and C conductors are not shown. It should be understood that the SID also includes switch-side connectors 68b - c for the cables of the switches of phase B and C conductors. Also shown are example signals generated at or provided to various components in the switch 28 of the phase A conductor and transmitted through the power, status, and sensor cable 24; namely, switch - open 110, switch - closed 111, switch open / closed status 112, current - polarity 113, current - return 114, supply voltage - polarity 115, load voltage - polarity 116, and voltage - return 117. Similar signals are generated at or provided to various components in the switches of phase B and C conductors via the respective power, status, and sensor cables 24. The terminal block 80 is configured to supply switch power signals to each of the switches 28a - c in phase conductors A, B, and C to open from the closed position or close from the open position.

[0057] Continuing to refer to Figure 6A , the junction box 16 has an analog-to-digital converter (ADC) or signal processing device 98, a main processor and memory 96, a communication module 100, a digital sampled value combination unit 102 (e.g., an IEC61850 module), and a time synchronization unit 104 (e.g., a GPS module). It should be understood that the ADC 98 and the main processor and memory indicated at 96 can each be separate units, or two or more of them can be integrated units. Additionally, the terms "module" and "unit" can each refer to an electronic circuit or a software function. Different modules or units can have overlapping circuits or share common software. Although in Figure 5 、 Figure 6A 、 Figure 6B 、 Figure 7A and Figure 7BThe various modules and units shown are physically different from each other, but in fact they do not need to be. For example, without providing every possible example, the ADC 98 can be physically incorporated into the circuitry of the processor 96 (e.g., a microcontroller), and so can the memory. The formatted digital signals according to a specified standard for communication with other devices (e.g., the IEC61850-9-2 standard) can be performed by the same processor or by a separate processing device that performs one or more of the operations of the communication module 100, the digital sampled value combining unit 102 (e.g., the IEC61850 module), and the time synchronization unit 104 (e.g., the GPS module). For ease of reference here, the operations of the communication module 100, the digital sampled value combining unit 102 (e.g., the IEC61850 module), and the time synchronization unit 104 (e.g., the GPS module) are collectively referred to as the data conversion and combination device 86.

[0058] According to Figure 5 , Figure 6A , Figure 6B , Figure 7A and Figure 7B In an example embodiment of, the junction box 16 of the SID 80 operates both as a convergence point for the wires from the recloser switches 28a - c and as a combining unit for measuring the current and voltage signals from each of the sensors 38a - c of the recloser switches, digitizing, sampling, and formatting the sampled values of the sensor data and status signal outputs for transmission together in a standard - based digital output format such as IEC 61850 - 9 - 2 to the recloser controller or IED 20. The processing in the SID 80 supports high - precision time synchronization according to, for example, the IEEE 1588V2 standard. For example, the sampled values are processed by a processor or a separate IEC 61850 - 9 - 2 unit to transmit a high - speed data set sample stream encoded in a multicast Ethernet frame. The processor 96 or the separate IEC 61850 - 9 - 2 unit 102 employs the IEC 61850 - 9 - 2 protocol with a publisher / subscriber model, where the publisher transmits unacknowledged data to the subscriber. According to the architecture of the example embodiment, the SID 80 acts as the publisher, and the recloser controller or IED 20 acts as the subscriber.

[0059] More specifically, one or more SID processors (i.e., according to an example embodiment, can be in the junction box 16 or, according to another embodiment described below, in the recloser switch) convert the analog sensor data values and switch status signal values into IEC61850-9-2LE sampled measurement values. Thus, simplified cable assemblies 90, 92 can be used between the junction box 16 and the control cabinet 18, and the junction box 16 and the control cabinet 18 only require a less complex cable 92 for the switched power signal to open and close the switchgear switches 28a-c and a simple and inexpensive data cable 90 (e.g., an optical fiber or Ethernet cable) for transmitting sensor data (e.g., phase conductor current and voltage) and switch status to the recloser controller 20, without the degradation associated with the capacitive coupling of the higher voltage signals on the wire bundle 54 from the conventional cable 26 as described in connection with FIGS. 3A and 3B. 1-4 Furthermore, the recloser controller 20 in the control cabinet 18 only needs to have an IEC61850-9-2 process bus to receive the sampled values of voltage and current from the junction box 16. Since the sensor and switch status data are received via simple optical fiber or Ethernet connectors 91 and the corresponding digital data cable 90 and a simpler and cheaper 8-pin count multi-pin cable 92 can be used to provide, for example, open-to-close commands and close-to-open commands to each of the switches 29a-c, there is no need to connect the expensive and bulky 14-pin to 42-pin connector 52 from the conventional cable 26 to the cabinet 18. Additionally, as referred to Figure 6B and Figure 7B above, the SID 80 can be configured with drive electronics 106 and thereby eliminate the need to use the 8-pin cable 92 to transmit the switched power signal as they can instead originate from the SID 80.

[0060] The SID 80 can receive signals from the switch sensors 38a - c, which can be any of such as high-precision low-power instrument transformers (LPITs) or optical sensors, bushing CTs, and / or voltage divider techniques embedded in the recloser switches 28a - c. The LPIT provides secondary signals proportional to the primary current and voltage values (e.g., according to the IEC 61869-6, IEC 61869-10, and IEC 61869-11 standards), and can enhance the visibility of the medium voltage (MV) grid by providing the accuracy and reliability required for advanced distribution automation functions by protection and instrumentation devices (IEDs), thereby improving the operating efficiency and automation capabilities in a cost-effective manner. The current measurement in the recloser switch 28 can be based on a Rogowski coil or an optical sensor, and the voltage measurement in the recloser switch 28 can be based on a resistive-capacitive voltage divider or an optical sensor. However, even with highly accurate sensors, due to the losses generated by the conventional 14 - 42 pin-count multi-pin cable 26 for transmitting the measured voltage and current values to the IED 20 as described in connection with FIGS. 3A and 3B, the conventional controller 20 does not receive data from these sensors 38 with sufficient integrity. On the other hand, the SID 80 is advantageous because it collects, digitizes, samples, and formats the sensor and switch status data for transmission to the IED 20 via a data connection (e.g., a fiber optic or Ethernet cable 90), which is separate from the open-to-close / close-to-open switch power signal provided to the SID 80 via a separate low pin-count (e.g., 8-pin) multi-pin cable 92 and then provided to the switches 28a - c. Thus, the SID 80 eliminates the problem of transmitting low-voltage or low-current analog signals on a conventional high pin-count multi-pin cable 26 assembly that is 40 - 50 feet long and is prone to signal noise and losses. In addition, the SID 80 eliminates the need for the recloser controller or the IED 20 to perform sensor data digitization (A / D conversion), thereby reducing the cost of the recloser controller or the IED 20.

[0061] Referring to Figure 6B, SID 80 includes the following components at the junction box 16; namely, an analog-to-digital signal processing device 98, a main processor and memory 96, a communication module 100, a digital sampled value combination unit 102 (e.g., an IEC61850 module), and a time synchronization unit 104 (e.g., a GPS module). SID 80 also includes drive electronics 106 for generating a switching power signal for each of the switches 28a-c in the phase conductors A, B, and C to open it from the closed position or close it from the open position, and an energy storage device 108, such as a capacitor, powered from a power source such as a battery disposed in the junction box. For example, the power source can receive power from a voltage transformer 36. The decision to open or close the switch 28 can be performed by the main processor 96, for example, based on the received sensor data signal, which in turn operates the drive electronics 106. Alternatively, the decision to open or close the switch can be performed by the IED 20, which in turn sends a switch control signal to the main processor 96 via the digital data cable 90. Thus, Figure 6B the example embodiment of SID 80 shown in

[0062] Figure 7A depicts another example embodiment, in which SID 80 includes both the switches 28a-c and the components at the junction box 16. For example, the analog-to-digital signal processing device 98, the main processor and memory 96, the communication module 100, the digital sampled value combination unit 102 (e.g., an IEC61850 module), and the time synchronization unit 104 (e.g., a GPS module) are disposed at the switches 28a-c, and the operation of these switches 28a-c is the same as that in Figure 6A and 6BThose provided at the junction box 16 in the illustrated embodiments are similar. The analog-digital signal processing device 98, the main processor and memory 96, the communication module 100, the digital sampled value combination unit 102 (e.g., IEC61850 module), and the time synchronization unit 104 (e.g., GPS module) may be provided at each of the switches 28a-c, or alternatively, a common data conversion and combination device (not shown) may be implemented at a switchgear including one or more of the analog-digital signal processing device 98, the main processor and memory 96, the communication module 100, the digital sampled value combining unit 102 (e.g., IEC61850 module), and the time synchronization unit 104 (e.g., GPS module) shared by the three switches 28a-c, and non-shared dedicated components are provided at each of the switches 28a-c. The SID 80 also includes a terminal block 118 at the junction box 16 for supplying the switch power signals received from the control cabinet 18 to the corresponding switches among the switches 28a-c via the 4-pin connectors 120a-c and the corresponding cables 128a-c. The SID 80 also includes a communication hub 124 at the junction box 16 for transmitting the digital data signals received from each of the switches 28a-c or alternatively from the common data conversion and combination device to the digital data cable 90 connecting the junction box 16 to the control cabinet 18.

[0063] Referring to Figure 7B the illustrative embodiment shown, the SID 80 components at the junction box 16 may further include drive electronics 106 for generating switch power signals for each of the switches in the phase conductors A, B, and C to open them from the closed position or close them from the open position, and an energy storage device 108, such as a capacitor, powered from a power source such as a battery provided in the junction box. For example, the power source may receive power from the voltage transformer 36. The decision to open or close the switch may be performed by the main processor 96, for example, based on the received sensor data signal, which in turn sends a control signal via the digital data cable 126 to operate the drive electronics 106. Alternatively, the decision to open or close the switch may be performed by the IED 20, which in turn sends a switch control signal to the main processor 96 via the digital data cable 90. Thus, Figure 7B the example embodiment of the SID 80 shown eliminates the need for a reduced-pin-count cable 92 (e.g., an 8-pin-count multi-pin cable) to transmit the switch power signals, as they may instead originate from the SID 80.

[0064] As described herein, the IED 20 is a microprocessor-based controller for power system equipment such as circuit breakers, transformers, and capacitor banks. For example, the IED 20 receives data from sensors 38 and power equipment 28 and can issue control commands such as tripping a circuit breaker if the IED senses abnormal voltage, current, or frequency, or raising / lowering the voltage level to maintain a desired level. Known types of IEDs include relay protection devices, load tap changer controllers, circuit breaker controllers, capacitor bank switches, recloser controllers, voltage regulators, etc.

[0065] As described herein, the IEC61850 standard from the International Electrotechnical Commission (IEC) is a standard for communication networks and systems that promotes interoperability between intelligent electronic devices (IEDs) from different manufacturers by using common engineering models, data formats, and communication protocols.

[0066] Example embodiments of the SID 80 and its method of use provide innovative methods to improve the sensor performance and the quality of sensor data (better accuracy, precision, linearity, noise reduction, harmonic response, etc.) of overhead recloser switchgear. The advantages of the example embodiments are simplified cable routing, improved sensor data fidelity for increased accuracy of sensor data reading, and improved accuracy of data and control functions based on sensor data (i.e., more precise switching at the switchgear, more precise power grid control and monitoring (e.g., power grid sector operating status and control)). Even when using more expensive sensors to obtain higher accuracy switchgear, the data quality issues explained above still exist and are not addressed in the example embodiments. The improved sensor data fidelity of the switchgear is characterized by, for example, the sensor data at the sensor being accurately presented at the controller without significant corruption from noise or capacitive coupling associated with the signal wires between the sensor and the controller. The simplified cable routing results in less weight and tension on the junction box and control cabinet, making it easier to install in the field and protecting the junction box or the associated switchgear housing and control cabinet from mechanical stress to extend the housing life or field life. The field installation of the control cabinet using the SID 80 and the associated simplified cable routing according to the example embodiments also simplifies calibration (e.g., requires fewer calibration factors).

[0067] More accurately delivering sensor data to a controller provides the following advantages: better fault detection, better sectionalization of the grid in which the power distribution line operates, improved synchrophasor applications, and other advantages. For example, improving the sensing performance from overhead recloser switchgear and the overall quality of sensor data enables utilities to use this data for critical and sensitive applications such as: a) improving power quality measurements at the recloser controller; b) improving current sensing accuracy, especially high current fault sensing accuracy; and c) increasing the sectionalization of circuits with a large number of customers so that utilities can install more reclosers over shorter spans and still successfully coordinate them. These advantages of the SID 80 help reduce the number of customers affected by permanent or momentary outages. In addition, the SID 80 can improve the performance of high impedance fault detection algorithms implemented in the recloser controller. The SID 80 can improve the reliability of open wire detection or neutral open detection algorithms. Using the high-quality sensor data provided by the SID 80 enables utilities to deploy distribution phase measurement units (PMUs) and effectively use the information for distribution system modeling, fault location, predictive maintenance, and situational awareness. Thus, according to an example embodiment of the present disclosure, utilities can utilize one or more SID 80s to maximize the use of their existing distribution assets rather than adding more equipment, sensors, etc. to achieve more desirable features, communications, data storage, and network security, etc. The SID 80 provides utilities with the ability to improve power quality issues through high DG / DER penetration rates (e.g., anti-islanding, voltage vector offset, ROCOF) and the ability to sectionalize and coordinate multiple reclosers due to improved CT fault sensor signal reporting accuracy, which is particularly useful in urban areas with short feeders and a large number of customers. The conventional cables and equipment described above in connection with FIGS. 1A through 4 provide insufficient sensor data quality for critical applications such as open wire detection, high impedance (Z) fault detection, distribution PMU, or precise fault location. The SID 80 of the example embodiment provides higher quality sensor data for successful use in these critical applications.

[0068] Those skilled in the art will understand that the application of the present disclosure is not limited to the construction details and component arrangements set forth in the above description or the accompanying drawings. The embodiments herein can have other embodiments and can be practiced or carried out in various ways. In addition, it should be understood that the wording and terminology used herein are for descriptive purposes only and should not be regarded as limiting. The terms "including", "comprising" or "having" and their variants used herein mean including the items listed below and their equivalents as well as additional items. Unless otherwise limited, the terms "connected", "coupled" and "mounted" and their variants are used broadly herein and include direct and indirect connections, couplings and mountings. In addition, the terms "connected" and "coupled" and their variants are not limited to physical or mechanical connections or couplings. In addition, terms such as upper, lower, bottom and top are relative and are used to assist in the description but are not limited thereto.

[0069] The components of the illustrative devices, systems and methods employed according to the illustrated embodiments can be implemented at least in part in digital electronic circuitry, analog electronic circuitry, or computer hardware, firmware, software, or combinations thereof. For example, these components can be implemented as a computer program product for execution or control of its operations by a data processing apparatus, such as a programmable processor, a computer, or multiple computers, such as a computer program, program code, or computer instructions tangibly embodied in an information carrier or a machine-readable storage device.

[0070] The computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for a computing environment. The computer program can be deployed to be executed on one computer or multiple computers, which are located at one site or distributed over multiple sites and interconnected by a communication network. In addition, the functional programs, codes, and code segments for implementing the illustrative embodiments can be readily interpreted by those skilled in the art of the illustrative embodiments as being within the scope of the claims illustrated by the illustrative embodiments. The method steps associated with the illustrative embodiments can be executed by one or more programmable processors that execute computer programs, codes, or instructions to perform functions (e.g., by operating on input data and / or generating output). The method steps can also be executed by dedicated logic circuitry, and the devices of the illustrative embodiments can be implemented as dedicated logic circuitry, e.g., an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0071] The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0072] For example, processors suitable for the execution of a computer program include both general and special purpose microprocessors, and any one or more processors of any type of digital computer. Generally, a processor receives instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also includes one or more mass storage devices for storing data (e.g., magnetic disks, magneto-optical disks, or optical disks) or operatively coupled to the mass storage device to receive data therefrom or to transfer data thereto or both. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, flash memory devices, and data storage disks (e.g., magnetic disks, internal hard disks, or removable disks, magneto-optical disks as well as CD-ROM and DVD-ROM disks). The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[0073] Those skilled in the art will appreciate that any of a variety of different technologies and techniques may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0074] Those skilled in the art will further understand that the various illustrative logical blocks, modules, circuits, and algorithmic steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been generally described above in terms of their functionality. Whether this functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the claims as illustrated by the illustrative embodiments. Software modules can reside in random access memory (RAM), flash memory, ROM, EPROM, EEPROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. In other words, the processor and the storage medium can reside in an integrated circuit, or can be implemented as discrete components.

[0075] Computer-readable non-transitory media include all types of computer-readable media, including magnetic storage media, optical storage media, flash media, and solid-state storage media. It should be understood that software can be installed in a central processing unit (CPU) device and sold with it. Alternatively, the software can be obtained and loaded into the CPU device, including obtaining the software through a physical medium or a distribution system, including, for example, obtaining the software from a server owned by the software creator or from a server not owned but used by the software creator. For example, the software can be stored on a server for distribution over the Internet.

[0076] The foregoing description and drawings are provided by way of example only and are not intended to limit the illustrative embodiments in any way unless set forth in the following claims. In particular, it should be noted that those skilled in the art can readily combine the various technical aspects of the various elements of the various illustrative embodiments in many other ways, all of which are considered to be within the scope of the claims.

Claims

1. A method for communication between a medium voltage overhead switchgear and an intelligent electronic device (IED), the switchgear being installed at a distal end of a utility pole and connected to a distribution line, the utility pole having a proximal end fixed to a ground support and an IED fixed at the proximal end, the switchgear having sensors at a switch disposed at one of three phase conductors associated with the distribution line, the method comprising: Receiving an analog signal providing a representation of current and voltage measured by the sensors at the switch, and at least one status signal indicating one of an open state and a closed state of the switch; Digitizing the analog signal to thereby generate a corresponding digital input; Sampling the digital input; Combining the samples into a set of combined digital samples having a specified format and including a digital representation of current or voltage of the corresponding one of the phase conductors measured by the sensors, the status signal, and metadata selected from at least one of an identification of the sensor from which the corresponding digital sample in the digital samples originated, an identification of the switch, an identification of the switchgear, and location data; Performing the receiving, digitizing, sampling, and combining via one or more components at a switchgear interface device located near the switch and at the distal end of the utility pole; And Providing the combined digital samples and the metadata as an output to a digital data connector located at the switchgear interface device and configured to be connected to a digital data cable.

2. The method according to claim 1, further comprising connecting a digital data cable between the digital data connector and the IED, the digital data cable being selected from an optical fiber cable and an Ethernet cable, and the digital data connector being selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the digital data cable.

3. The method according to claim 1, wherein the combining includes formatting the combined digital samples using the IEC61850 standard from the International Electrotechnical Commission (IEC).

4. The method according to claim 3, wherein the combining includes: Formatting the combined digital samples using the IEC61850-9-2 protocol from the IEC, the combined digital samples being encoded in a multicast Ethernet frame; And Transmitting the unacknowledged data of the combined digital samples from the switchgear interface device operating as a publisher to subscribers including the IED according to the IEC61850-9-2 protocol.

5. The method according to claim 3, wherein the combining further includes providing global positioning system (GPS) time synchronization to the combined digital samples.

6. A switchgear interface device for installation on a distal end of a utility pole and connected to a medium voltage overhead switchgear of a distribution line, the utility pole having a proximal end fixed to a ground support and a cabinet with a smart electronic device (IED) fixed at the proximal end, the switchgear having sensors at a switch disposed at one of three phase conductors associated with the distribution line, the switchgear interface device comprising: A housing configured to be disposed adjacent to the switchgear and installed on the distal end of the utility pole; A plurality of inputs at the housing configured to receive analog signals providing representations of current or voltage measured by the sensors at the switch, and to receive at least one status signal indicating one of an open and a closed state of the switch; A processor disposed within the housing and configured to digitize the analog signals and the at least one status signal to thereby generate corresponding digital inputs, sample the digital inputs, and combine the samples into a set of combined digital samples, the set of combined digital samples having a specified format and including digital representations of current and voltage of a corresponding one of the phase conductors measured by the sensors, status signals, and metadata selected from at least one of an identification of the sensor from which the corresponding digital sample in the digital samples originated, an identification of the switch, an identification of the switchgear, and location data; A memory disposed within the housing and configured to store the set of combined digital samples; And A digital data connector connected to the housing and configured to be connected to a digital data cable selected from an optical fiber cable and an Ethernet cable, and to provide the combined digital samples and the metadata as an output to the digital data cable and the IED when the digital data cable connects the digital data connector and the IED, the digital data connector selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the digital data cable.

7. The switchgear interface device according to claim 6, further comprising drive electronics and an energy storage device for powering the drive electronics, the processor being configured to receive a switch command signal transmitted via the digital data cable from the IED at the digital data connector, and to operate the drive electronics to send a switching power signal to the switch to open or close according to the switch command signal.

8. The switchgear interface device according to claim 6, further comprising: A switched power signal connector is connected to the housing and is configured to be connected to a second cable separate from the digital data cable, and to receive, via the second cable, switched power signals for the switch, including close-to-open signals and open-to-close signals, from the IED when the second cable connects the switched power signal connector and the IED. The switched power signal connector includes at least one of pins and sockets that receive corresponding ones of the switched power signals and supply them to a terminal block in the housing that is electrically connected to a switch actuation mechanism in the switch.

9. The switchgear interface device according to claim 6, wherein the specified format is the IEC61850 standard from the International Electrotechnical Commission (IEC).

10. The switchgear interface device according to claim 9, wherein the processor is configured to employ the IEC61850-9-2 protocol from the IEC, wherein the processor operates as a publisher and transmits unacknowledged data to subscribers including the IED, the unacknowledged data including the merged digital samples encoded in a multicast Ethernet frame.

11. The switchgear interface device according to claim 9, wherein the processor is configured to employ Global Positioning System (GPS) time synchronization of the merged digital samples.

12. The switchgear interface device according to claim 6, wherein the switchgear has a second switch and a third switch respectively disposed at the other two of the three phase conductors, wherein, a plurality of inputs at the housing are configured to receive analog signals providing representations of current or voltage measured by sensors disposed at each of the second switch and the third switch, and to receive status signals indicating one of open and closed states of the second switch and the third switch; and the processor is configured to digitize the analog signals and status signals from the second switch and the third switch to thereby generate corresponding digital inputs, sample the digital inputs, and combine the samples into the one set of merged digital samples having the specified format such that the one set of merged digital samples generated by the processor also includes digital representations of current and voltage of the other two of the phase conductors measured by their corresponding sensors, status signals of each of the switches at the other two of the phase conductors, and metadata corresponding to the sensors of the second switch, the third switch, and the other two of the phase conductors.

13. A switchgear interface device (SID) for installation on a distal end of a utility pole and connected to a medium voltage overhead switchgear of a distribution line, the utility pole having a proximal end fixed to a ground support and a cabinet with a smart electronic device (IED) fixed at the proximal end, the switchgear having sensors at a switch disposed at one of three phase conductors associated with the distribution line, the switchgear being arranged adjacent to a junction box at the distal end of the utility pole, the switchgear interface device comprising: A switch SID assembly disposed near the switch and electrically connected to the switch, the switch SID assembly comprising: A processor configured to receive an analog signal from the sensor that is representative of a current or voltage measured by the sensor at the switch, and at least one status signal indicating one of an open state and a closed state of the switch, digitize the analog signal and the at least one status signal to thereby generate corresponding digital outputs, sample the digital outputs, and combine the samples into a set of combined digital samples, the set of combined digital samples having a specified format and including digital representations of the current and voltage of a corresponding one of the phase conductors measured by the sensor, the status signal, and metadata selected from at least one of an identification of the sensor from which the corresponding digital sample in the digital samples in the sensor is derived, an identification of the switch, an identification of the switchgear, and location data; A memory configured to store the set of combined digital samples; and A digital data connector configured to connect to a digital data cable selected from an optical fiber cable and an Ethernet cable, and provide the combined digital samples and the metadata to a junction box when the digital data cable connects the digital data connector and the junction box, the digital data connector being selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the digital data cable.

14. The switchgear interface device according to claim 13, further comprising: A second digital data connector mounted on the junction box and configured to connect to the digital data cable, and receive the combined digital samples and the metadata from the switch SID assembly when the digital data cable connects the digital data connector and the second digital data connector on the junction box; A third digital data connector connected to the junction box and configured to connect to a second digital data cable selected from an optical fiber cable and an Ethernet cable, and provide the combined digital samples and the metadata as an output to the second digital data cable and an IED when the second digital data cable connects the third digital data connector and the IED, the third digital data connector being selected from an optical fiber cable connector and an Ethernet cable connector corresponding to the second digital data cable; And A communication hub disposed in the junction box and having a plurality of ports, and configured to provide a signal received at one of the ports to one or more of the other ports among the plurality of ports, the second digital data connector and the third digital data connector being connected to corresponding ports among two of the plurality of ports, the communication hub being operable to provide the combined digital samples and the metadata received at the second digital data connector to the third digital data connector.

15. The switchgear interface device according to claim 14, further comprising: Drive electronics in the junction box and an energy storage device in the junction box that powers the drive electronics; And A multi-pin connector at each of the junction box and the switch, which is connected to the digital data cable and the switched power signal cable separated from the digital data cable through an interface. The multi-pin connector at the switch is electrically connected to the actuating mechanism of the switch, and the multi-pin connector at the junction box is electrically connected to the drive electronics; Wherein the processor is configured to receive a switch command signal transmitted from the IED via the communication hub, the second digital data cable, and the digital data cable at the digital data connector, and send a control signal to the drive electronics via a digital signal cable to operate the drive electronics to send a switched power signal to the switch to open or close according to the switch command signal; and Wherein the switched power signal cable transmits the switched power signal to the switch.

16. The switchgear interface device according to claim 13, wherein the specified format is the IEC61850 standard from the International Electrotechnical Commission (IEC).

17. The switchgear interface device according to claim 16, wherein the processor is configured to adopt the IEC61850-9-2 protocol from the IEC, wherein the processor operates as a publisher and sends unacknowledged data to subscribers including the IED, and the unacknowledged data includes the merged digital samples encoded in a multicast Ethernet frame.

18. The switchgear interface device according to claim 16, wherein the processor is configured to adopt Global Positioning System (GPS) time synchronization for the merged digital samples.

19. The switchgear interface device according to claim 13, wherein the switchgear includes a second switch disposed at the other two of the three phase conductors, and the switchgear interface device further includes a second electronic circuit disposed near the second switch. The second switch signal conditioning circuit includes: A second processor, configured to receive an analog signal that is a representation of a current or voltage measured by a sensor at the second switch, and at least one status signal indicating one of the open state and the closed state of the second switch, digitize the at least one status signal and the analog signal corresponding to the second switch to thereby generate a corresponding digital output, and sample the digital output of the second switch; and A second memory, configured to store the samples of the second switch.

20. The switchgear interface device according to claim 19, wherein the processor includes a data conversion and combination device, and the data conversion and combination device is configured to: Combine the stored samples from the second switch into a second combined digital sample, the second combined digital sample having a specified format and including digital representations of current and voltage measured at the second switch, the at least one status signal corresponding to the second switch, and second metadata selected from at least one of an identification of a sensor from which a corresponding digital sample in the digital samples of the second set of sensors was derived, an identification of the second switch, and identification and location data of the switching device; and Combine the one combined digital sample and the second combined digital sample and provide them via the digital data connector to the junction box.

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