Ring main unit electric signal digitizing device and system and ring main unit

Abstract

The invention relates to a ring main unit electric signal digitizing device and system and a ring main unit, which are installed in an incoming and outgoing line cabinet secondary chamber of the ring main unit and comprise a signal processing loop, a display and interaction module, an interface communication module, a microprocessor and a control loop. Wherein the interface communication module comprises a first aviation plug wire and a second aviation plug wire; the signal processing loop is connected with a primary chamber of the incoming and outgoing line cabinet through the first aviation plug wire, and is used for acquiring an operation state signal of the incoming and outgoing line cabinet and performing digital processing; and the microprocessor is connected with the station terminal through the second aviation plug wire and is used for receiving a control instruction. Therefore, four functions of sampling, display, control and communication are integrated; and through a first aviation plug wire and a second aviation plug wire of the interface communication module, the connection between the digitization device and the primary chamber of the incoming and outgoing line cabinet and the station terminal is realized, cables are reduced, and when an outgoing line cabinet is newly increased, only the digitization device needs to be accessed to the same digital bus, so that plug-and-play type capacity expansion is realized.

Description

Technical Field

[0001] This application relates to the field of high-voltage electrical equipment technology, and in particular to ring main unit (RNU) electrical signal digitization devices, systems, and RNUs. Background Technology

[0002] In medium-voltage distribution network ring main units (RNBs), voltage transformers are installed in the PT cabinet of the RNB box, current transformers are installed in the primary compartment of the bay cabinet, and the opening and closing operation modules are placed in the secondary compartment of the bay cabinet. Depending on the application, there are two types of station terminals: centralized and distributed. Existing centralized station terminals require AC voltage and current to be connected to the centralized station terminal via cables; distributed station terminals require AC voltage to be connected to the bay unit on each bay cabinet via cables. Both methods result in long cable lengths, poor analog signal stability, and low reliability, making installation and maintenance cumbersome. Furthermore, expanding the capacity of either type of RNB is very difficult, requiring the AC voltage or current to be led out through the PT cabinet or bay cabinet of the RNB box and connected to the newly added cabinet. Summary of the Invention

[0003] This application provides a ring main unit electrical signal digitization device, system, and ring main unit to at least solve the problems of excessively long cables and difficulties in capacity expansion in existing ring main units in related technologies.

[0004] In a first aspect, embodiments of this application provide a ring main unit electrical signal digitization device. The digitization device is installed in the secondary compartment of the incoming and outgoing line cabinets of the ring main unit and includes a signal processing circuit, a display and interaction module, an interface communication module, a microprocessor, and a control circuit; wherein... The interface communication module includes a first flight connector and a second flight connector; The signal processing loop is connected to the primary compartment of the incoming / outgoing line cabinet via the first aviation connector, and is used to collect the operating status signal of the incoming / outgoing line cabinet and perform digital processing to generate digital operating data and send it to the microprocessor. The display and interaction module is connected to the microprocessor and the control loop respectively, and is used to receive and display the digital operation data through the microprocessor, and to obtain and output the user's manual operation commands to the control loop. The microprocessor is connected to the station terminal via the second navigation cable and is used to receive control commands and operating status signals, process the operating status signals according to the control commands, or control the operation of the signal processing loop, display and interaction module, receiving and decoding loop, encoding uplink loop or control loop according to the control commands. The control loop is connected to the display and interaction module and the microprocessor respectively, and is used to drive the circuit breaker of the incoming and outgoing line cabinet to open or close according to the control command or manual operation instruction.

[0005] In one embodiment, the microprocessor includes an uplink encoding loop, an MCU, and a downlink encoding loop; wherein, The encoding uplink loop is used to encode the digital running data according to a preset format, generate uplink frame data, and send it to the station terminal. The receiving and decoding circuit is used to receive downlink frame data sent by the station terminal, perform decoding processing, generate frame data, and send it to the microprocessor; The MCU is used to convert or process the digital operating data and output it to the display and interaction module, and to parse the frame data to obtain the control instructions and execute them.

[0006] In one embodiment, the uplink and downlink communication between the receiving decoding loop, the encoding uplink loop and the station terminal all adopt the timing-based FT3 protocol, and the frame data structure includes a sampling delay time stamp and a preset frame header; The microprocessor is also used to send uplink frame data to the station terminal according to the sampling delay time stamp after the received frame data contains the preset frame header; the uplink frame data is used to realize the sampling synchronization of the PT cabinet voltage signal and the electrical signals in the incoming and outgoing line cabinets.

[0007] In one embodiment, the signal processing loop includes a signal sampling interface, an isolation circuit, and a signal processing circuit; wherein, The signal sampling interface is used to receive the operating status signal and send it to the signal processing circuit; The isolation circuit is used to achieve signal transmission and power isolation; The signal processing circuit is used to amplify and convert the operating status signal to obtain the digital operating data.

[0008] In one embodiment, the display and interaction module includes a data display module, an operation button module, and a warning indication module; wherein, The data display module is used to present the digital operating data to the user; The operation button module is used to manually control the control circuit of the incoming and outgoing line cabinet; The warning indication module is used to issue a warning signal to the user when there is an abnormality in the line in the ring main unit.

[0009] In one embodiment, the receiving decoding circuit includes a first protection circuit, a first 485 high-speed chip, and an FPGA decoding chip connected in series, wherein... The first protection circuit is used to protect the integrity of the signal during transmission; The first 485 high-speed chip is used to convert the differential voltage signal of the A / B lines into Manchester encoded data; The FPGA decoding chip is used to convert the received Manchester-encoded data into digital signals.

[0010] In one embodiment, the encoding uplink circuit includes an XOR logic gate, a capacitor isolation chip, a second 485 high-speed chip, and a second protection circuit connected in series, wherein... The XOR logic gate is used to convert the digital running data into Manchester encoded data; The capacitor isolation chip is used to transmit digital signals through capacitive coupling, ensuring electrical isolation between communication and the main circuit. The second 485 high-speed chip is used to convert Manchester encoded data into A / B line differential voltage signals; The second protection circuit is used to protect the integrity of the signal.

[0011] In one embodiment, the control loop includes: The energy storage control circuit is used to control the on / off state of the energy storage relay, thereby controlling the energy stored in the motor. The open / closed position indicator control circuit is used to control the on / off state of the open / closed position indicator light to display the open / closed status of the circuit breaker. The protection relay control circuit is used to control the on / off state of the protection opening and closing relays; The remote control circuit for opening and closing the circuit breaker is used to control the remote opening and closing operation. The local opening and closing control circuit is used to control the local opening and closing operations; The opening and closing holding control circuit is used to control the opening and closing holding relay to close and hold until the opening and closing action is completed.

[0012] Secondly, this application provides a ring main unit electrical signal digitization system, including a station terminal and a ring main unit electrical signal digitization device as described in any of the above embodiments. The station terminal communicates with the ring main unit electrical signal digitization device through the interface communication module.

[0013] Thirdly, embodiments of this application provide a ring main unit, including a station terminal and a ring main unit electrical signal digitization device as described in any of the above embodiments.

[0014] The ring main unit electrical signal digitization device, system, and ring main unit provided in this application embodiment have at least the following technical effects: The digitization device is installed in the secondary compartment of the incoming / outgoing line cabinet of the ring network box, and includes a signal processing circuit, a display and interaction module, an interface communication module, a microprocessor, and a control circuit. The interface communication module includes a first and a second hop cable. The signal processing circuit is connected to the primary compartment of the incoming / outgoing line cabinet via the first hop cable, and is used to collect the operating status signals of the incoming / outgoing line cabinet, perform digitization processing, generate digital operating data, and send it to the microprocessor. The microprocessor is connected to the station terminal via the second hop cable, and is used to receive control commands and operating status signals, process the operating status signals according to the control commands, or control the operation of the signal processing circuit, display and interaction module, receiving and decoding circuit, encoding uplink circuit, or control circuit according to the control commands. Therefore, this application integrates the four major functions of sampling, display, control, and communication into a single device, replacing the traditional distributed secondary equipment; and through the first and second port cables of the interface communication module, it realizes the connection between the digital device and the primary room and station terminal of the incoming and outgoing line cabinets, reducing more than 90% of the cables in the ring network cabinet, reducing the wiring error rate, saving materials and installation time. When adding new incoming and outgoing line cabinets, only the digital device needs to be connected to the same digital bus, without modifying the original cable layout, realizing "plug and play" capacity expansion.

[0015] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a structural block diagram of the ring main unit electrical signal digitization device in one embodiment of this application; Figure 2 This is a structural block diagram of the encoded uplink loop in one embodiment of this application; Figure 3 This is a structural block diagram of the decoding receiving loop in one embodiment of this application; Figure 4 This is a structural block diagram of a signal processing circuit in one embodiment of this application; Figure 5 This is a structural block diagram of the display and interaction module in one embodiment of this application; Figure 6 This is a schematic diagram of the operation interface displayed on the front of the ring main unit in one embodiment of this application; Figure 7 This is a circuit diagram of the control loop in one embodiment of this application; Figure 8This is a schematic diagram of the back-side interface communication module of the ring main unit in one embodiment of this application; Figure 9 This is a schematic diagram of the display screen in the front display operation interface of the ring main unit in one embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0018] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0019] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0020] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0021] In a first aspect, embodiments of this application provide a ring main unit electrical signal digitization device, wherein the digitization device is installed in the secondary compartment of the incoming and outgoing line cabinets of the ring main unit, referring to... Figure 1 It includes a signal processing circuit, a display and interaction module, an interface communication module, a microprocessor, and a control circuit.

[0022] The interface communication module includes a first and a second connector. The signal processing circuit is connected to the primary compartment of the incoming / outgoing line cabinet via the first connector, used to collect the operating status signals of the incoming / outgoing line cabinet and perform digital processing to generate digital operating data, which is then sent to the microprocessor via the SPI bus. The display and interaction module is connected to the microprocessor and the control circuit, respectively. It is connected to the microprocessor via the IIC bus and triggers the control circuit via a button. It is used to receive and display the digital operating data through the microprocessor, acquire the user's manual operation commands, and output them to the control circuit. The microprocessor is connected to the station terminal via the second connector, used to receive control commands and operating status signals, process the operating status signals according to the control commands, or control the operation of the signal processing circuit, display and interaction module, receiving and decoding circuit, encoding uplink circuit, or control circuit according to the control commands. The control circuit is connected to the display and interaction module and the microprocessor, respectively. The microprocessor is connected to the control circuit via a GPIO port, used to drive the circuit breaker of the incoming / outgoing line cabinet to open or close according to the control commands or manual operation commands.

[0023] In this embodiment, the microprocessor includes an uplink encoding circuit, an MCU, and a downlink encoding circuit. Both the uplink and downlink encoding circuits are connected to the MCU via an SPI bus. The uplink encoding circuit encodes the digital operation data according to a preset format, generates uplink frame data, and sends it to the station terminal. The receiving / decoding circuit receives the downlink frame data sent by the station terminal, decodes it, generates frame data, and sends it to the microprocessor. The MCU converts or processes the digital operation data and outputs it to the display and interaction module, parses the frame data to obtain the control commands, and executes them.

[0024] In a preferred embodiment, the encoded uplink circuit includes an XOR logic gate, a capacitor isolation chip, a second 485 high-speed chip, and a second protection circuit connected in series. The XOR logic gate converts the digital running data into Manchester-encoded data; the capacitor isolation chip transmits digital signals via capacitive coupling, ensuring electrical isolation between communication and the main circuit; the second 485 high-speed chip converts the Manchester-encoded data into A / B line differential voltage signals; and the second protection circuit protects signal integrity. (Reference) Figure 2The uplink encoding circuit transmits the sampled signal to the station terminal via a digital bus in a specific FT3 frame format. It consists of an isolated power supply, a capacitor isolation chip, a 485 high-speed chip, an MCU's SPI bus, and an XOR logic gate. The MCU sends the digital signal converted by the sampling circuit to the XOR logic gate via the SPI port to convert it into Manchester encoding. The Manchester code baud rate is 20 Mbits / s, and the data baud rate is 10 Mbits / s.

[0025] In a preferred embodiment, the receiving decoding circuit includes a first protection circuit, a first 485 high-speed chip, and an FPGA decoding chip connected in series. The first protection circuit protects the integrity of the signal during transmission; the first 485 high-speed chip converts the A / B line differential voltage signal received from the station terminal into Manchester-coded data; and the FPGA decoding chip converts the received Manchester-coded data into a digital signal. (Reference) Figure 3 The receiving and decoding circuit is used to receive and parse Manchester code data frames sent from the station terminal. It consists of an isolated power supply, a 485 high-speed chip, a capacitor isolation chip, and an FPGA decoding chip circuit. The FPGA converts the Manchester code (Manchester code baud rate of 20 Mbits / s) sent from the station terminal into ordinary data frames and forwards them to the MCU through the SPI port. The MCU executes data sampling synchronization processing, control commands, parameter uploading, and other commands according to the data frame parsing command.

[0026] In one embodiment, the signal processing loop includes a signal sampling interface, an isolation circuit, and a signal processing circuit. The signal sampling interface is used to receive the operating status signal and send it to the signal processing circuit; the isolation circuit is used to achieve signal transmission and power isolation; and the signal processing circuit is used to amplify and convert the operating status signal to obtain the digital operating data.

[0027] For more specific references Figure 4The sampling signal processing loop is mainly connected to the sampling signals and status quantities in the incoming and outgoing line cabinet. The analog quantities of each status signal are collected and converted into digital quantities, which are output through the digital bus without any additional cables. The sampling signals include three-phase AC voltage, three-phase AC current, AC zero-sequence current, DC voltage and current of the trip coil, DC voltage and current of the closing coil, and DC voltage and current of the energy storage coil. Analog-to-digital conversion is achieved through the 16-bit 8-channel synchronous ADC chip AD7606 and the 12-bit on-chip ADC of the processor MCU, respectively. There are 16 remote signaling channels, including open position, closed position, no energy storage position, low gas pressure interlock, disconnect switch position, grounding switch position, control circuit disconnection, protection trip hard pressure plate engaged status, reclosing hard pressure plate engaged status, remote trip hard pressure plate engaged status, remote closing hard pressure plate engaged status, fault reset, remote / local status, FA status, closing button status, and trip button status. The high and low levels are detected by the high-speed GPIO of the MCU to achieve digitization.

[0028] All signal processing loops are isolated to 1.5kV. AC sampling uses PT / CT isolation, the DC channel uses isolated operational amplifier circuits, and remote signaling status quantities use optocoupler isolation. After calibration, the sampling signal accuracy reaches 0.2% for voltage and current sampling, and 0.5% for the DC accuracy of the switch mechanical characteristics. The circuits are directly interchangeable in the field. This application ensures high electrical safety by using PT / CT isolation for AC sampling, isolated operational amplifiers for the DC channel, and optocoupler isolation (1.5kV isolation withstand voltage) for remote signaling quantities.

[0029] In one embodiment, reference Figure 5 The display and interaction module includes a data display module, an operation button module, and a warning indication module. The data display module presents the digital operating data to the user; the operation button module allows for manual control of the control circuits of the incoming and outgoing line cabinets; and the warning indication module issues a warning signal to the user when there is a line abnormality in the ring main unit.

[0030] For details, please refer to the following: Figure 6 The user interface LCD screen uses a customized low-power, wide-temperature-range LCD, capable of displaying three-phase AC voltage, zero-sequence voltage, three-phase AC current, zero-sequence current, three-phase cable temperature, and ambient humidity (display content reference). Figure 9The circuit breaker is controlled by Belling's BL55072 chip, which can drive 144 segments. The MCU samples, converts, and calculates the data items and status values, and sends them to the BL55072 via the SPI port to drive the LCD display. A one-second flashing running light indicates normal operation. When the voltage value is higher than 30%, the energized indicator light illuminates. An alarm light illuminates when a line abnormality is detected. The open / close indicator lights indicate the current circuit's open / close status. Operation buttons include a reset button, LCD page turning, open / close buttons, and when the remote / local button is set to local, the circuit breakers in the incoming and outgoing cabinets can be operated via the open / close buttons. Four hard-plate locking devices are used for remote control protection locks; remote operation is only possible when these plates are engaged.

[0031] In one embodiment, the control circuit includes: an energy storage control circuit for controlling the on / off state of the energy storage relay to control the energy storage of the motor; an open / close position indication control circuit for controlling the on / off state of the open / close position indicator light to display the open / close status of the circuit breaker; a protection relay control circuit for controlling the on / off state of the protection open / close relay; a remote open / close control circuit for controlling the remote open / close operation; a local open / close control circuit for controlling the local open / close operation; and an open / close holding control circuit for controlling the open / close holding relay to remain closed until the open / close operation is completed.

[0032] Control loop reference Figure 7 The control circuit in this embodiment consists of multiple switch contacts and relays. The relays include: energy storage control relay J1, trip position relay J2, pre-selection relay J3, reclosing control relay J4, closing holding relay J5, anti-pumping relay J6, remote closing relay J7, remote opening relay J8, trip control relay J9, closing position relay J10, and trip holding relay J11. The switch or relay contacts include: K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12, K13, and a local / remote selector knob XK1. These switches are controlled by the relays. The control circuit of this embodiment also includes a protection closing pressure plate N1, a local closing button N2, a remote closing pressure plate N3, a local tripping button N4, a remote tripping pressure plate N5, a first sampling resistor RS1, a second sampling resistor RS2, a circuit breaker closing coil HQ, a circuit breaker tripping coil TQ, DL open position node DL1 (normally closed), DL close position node DL2 (normally open), a short-circuit jumper protection device, a blocking node (optional node), a closing indicator light L1, and a tripping indicator light. For specific connection relationships, refer to [reference needed]. Figure 7 The wiring details and specific control logic are described below.

[0033] Regarding the energy storage control process, when the circuit breaker is in an unstored state, the digital unit operates the internal energy storage to control relay J1, causing contact switches K1 and K2 to close, the energy storage circuit to be connected, and the circuit breaker mechanism's energy storage motor M to operate until energy storage is completed.

[0034] For the trip position indication control process, when the circuit breaker is in the open position, the circuit breaker auxiliary normally closed contact DL trip position node (DL1) closes, forming a circuit through the positive power supply (V48+), the digital unit trip position monitoring relay (trip position relay J2), the DL trip position node, the circuit breaker closing coil HQ, and the negative power supply (V48-). The trip position relay J2 actuates, and simultaneously, the normally open contact of switch K13 closes, illuminating the trip position indicator L2. This illumination indicates that the circuit breaker is in the open position and the closing circuit is intact. For the closing position indication control process, when the circuit breaker is in the closed state, the circuit breaker auxiliary normally open contact DL closing position node (DL2) closes. The circuit is formed by the positive power supply (V48+), the digital unit closing position monitoring relay (closing position relay J10), DL closing position node (DL2), the circuit breaker trip coil TQ, and the negative power supply (V48-). The closing position relay J10 is activated. At the same time, the normally open contact of switch K12 closes, and the closing position indicator L1 lights up. The lighting of this indicator light reflects that the circuit breaker is in the closed position and the tripping circuit is intact.

[0035] For the protection closing control process, the protection closing pressure plate N1 is in place. After receiving the protection closing command, the digital unit will operate the protection closing relay (i.e., the reclosing control relay J4) to close the switch K7 contact. The circuit is formed by the positive power supply (V48+), the protection closing pressure plate N1, the switch K7, the DL opening node (DL1), the circuit breaker closing coil HQ, and the negative power supply (V48-). The closing coil HQ is energized until the circuit breaker completes the closing action. The DL opening node (DL1) opens to close the closing circuit, and the DL closing node (DL2) closes to prepare for the next opening. For the protection tripping control process, the protection tripping pressure plate N6 is in place. After receiving the protection tripping command, the digital unit will operate the protection tripping relay (tripping control relay J9) to close the switch K11 contact. The circuit is formed by the positive power supply (V48+), the protection tripping pressure plate N6, the switch K11, the DL closing node (DL2), the circuit breaker tripping coil TQ, and the negative power supply (V48-). The tripping coil TQ is energized until the circuit breaker completes the tripping action. The DL closing node (DL2) opens to close the tripping circuit, and the DL opening node (DL1) closes to prepare for the next tripping.

[0036] For the remote closing control process, knob XK1 is set to the remote position (i.e., XK1 is in the closed state) and remote closing pressure plate N3 is in place. After receiving the remote closing command, the digital unit will operate the remote closing relay J7 to close the contact of switch K8. The circuit is formed through positive power supply (V48+), switch K8, remote closing pressure plate N3, DL disconnecting node (DL1), closing coil HQ, and negative power supply (V48-). The closing coil HQ is energized until the circuit breaker completes the closing action. DL disconnecting node (DL1) opens to close the closing circuit, and DL closing node (DL2) closes to prepare for the next opening. For the remote tripping control process, with knob XK1 set to the remote position and remote tripping pressure plate N5 in place, the digital unit receives the remote tripping command and operates the remote tripping relay J8 to close the switch K9 contact. The circuit is formed through (V48+), switch K9, remote tripping pressure plate N5, DL closing node (DL2), circuit breaker tripping coil TQ, and negative power supply (V48-). The tripping coil TQ is energized until the circuit breaker completes the tripping action. The DL closing node (DL2) opens to close the tripping circuit, and the DL tripping node (DL1) closes to prepare for the next tripping.

[0037] For the local closing control process, knob XK1 is set to local (i.e., XK1 is in the open state) and remote closing pressure plate N3 is in place. Press the local closing button N2 of the digital unit. The circuit is formed by positive power supply (V48+), local closing button N2, remote closing pressure plate N3, DL disconnecting node (DL1), closing coil HQ, and negative power supply (V48-). The closing coil HQ is energized until the circuit breaker completes the closing action. The DL disconnecting node opens to close the closing circuit, and the DL closing node closes to prepare for the next opening. For the local tripping control process, with knob XK1 set to local and remote tripping pressure plate N5 in place, press the local tripping button N4 of the digital unit. The circuit is formed by the positive power supply (V48+), local tripping button N4, remote tripping pressure plate N5, DL closing node (DL2), tripping coil TQ, and negative power supply (V48-). The tripping coil TQ is energized until the circuit breaker completes the tripping action. The DL closing node opens to close the tripping circuit, and the DL tripping node closes to prepare for the next tripping.

[0038] For the closing and holding control process, when the closing current flows, the closing and holding relay J5 activates, and the switch K3 contacts close and hold until the DL open position (DL1) opens. This prevents the reclosing control relay J4 or the push button contacts from opening before the open position, thus preventing incomplete closing and ensuring reliable closing. For the opening and holding control process, when the opening current flows, the opening and holding relay J11 activates, and the switch K10 contacts close and hold until the DL close position (DL2) opens. This prevents the opening control relay or the push button contacts from opening before the close position, thus preventing incomplete opening and ensuring reliable opening.

[0039] In summary, the digital device in this embodiment collects AC signals, remote signaling, status signals, etc. from the incoming and outgoing line cabinets of the ring network box, converts them into digital quantities and sends them to the station terminal; it also receives instructions from the station terminal to perform remote control operation and status display of the incoming and outgoing line cabinets; and completes local opening and closing operations of the incoming and outgoing line cabinets.

[0040] In a preferred embodiment, the uplink and downlink communication between the receiving decoding loop, the encoding uplink loop, and the station terminal all adopt the timing-based FT3 protocol. The frame data structure includes a sampling delay time stamp and a preset frame header. The microprocessor is also used to send uplink frame data to the station terminal according to the sampling delay time stamp after the received frame data contains the preset frame header. The uplink frame data is used to realize the sampling synchronization of the PT cabinet voltage signal and the electrical signals in the incoming and outgoing line cabinets.

[0041] Specifically, the digital device of this application can also achieve synchronous sampling of electrical signals between each incoming and outgoing line cabinet. This method can ensure that the current synchronous sampling accuracy between each bay cabinet meets the consistency of ±2 minutes of angle difference, thereby realizing the synchronization of voltage sampling at the station terminal and the AC current digital signal sent by the bay cabinet. For example, the uplink and downlink communication of the digital bus between the digital device and the station terminal both adopt the timing-based FT3 protocol, with a sampling delay time stamp in the frame structure and a frame header of 0564H. The downlink communication frame of the station terminal is sent at intervals of 32 sampling points per single cycle of power frequency, starting with a frame header of 0564H. The uplink communication frame of the digital device is sent at intervals of 256 sampling points per single cycle of power frequency, containing 16 channels of single sampling point data, a sampling delay time stamp of 1, and a frame header of 0564H. The delay time stamp is the edge delay time from the start of sampling at each sampling point to the transmission of 0564H, with a precision resolution of 0.01µs. After each digitizing device captures the downlink 0564H frame header from the station terminal, it adjusts its sampling start time. Once sampling begins, it sends an uplink frame after a sampling delay time stamp of 1. When the delay time stamp 1 is the same fixed value, the electrical signal sampling of each digitizing device is synchronized. The calculation of the fixed value of the sampling delay time stamp 1 is based on the fact that from the start of sampling by the MCU to the acquisition of the digital signal by the MCU, there is generally a delay due to the signal conversion circuit. This delay time can be fixed at a certain empirical value using an RC signal modulation circuit, thus ensuring the synchronization of electrical signal sampling of each digitizing device. The station terminal adjusts its own voltage signal sampling time according to the electrical signal sampling delay time stamp 1 of the uplink frame from the electrical signal digitizing device to achieve synchronization of the PT cabinet voltage signal with the electrical signals in the incoming and outgoing line cabinets.

[0042] In summary, the digital device provided in this application has the following advantages over the prior art: First, it significantly improves system reliability and stability. Traditional ring main units use long-distance analog cables to transmit voltage / current signals, which are susceptible to electromagnetic interference, leading to a decrease in accuracy. In contrast, this application uses local digital processing: the sampled signals (AC voltage / current, DC coil parameters, and remote signaling status) are directly converted into digital signals (voltage / current accuracy up to 0.2%, DC characteristic accuracy 0.5%) in the incoming and outgoing line cabinets, and then transmitted to the station terminal via a digital bus. This enhances the anti-interference ability of signal transmission and completely avoids the problems of analog signal attenuation and interference.

[0043] Second, simplify the cabling structure and reduce maintenance costs. Existing technologies require multiple long cables to be routed from the PT cabinet and bay cabinet to the station terminal (centralized) or each bay unit (distributed). This application, however, requires only two key connections: From the primary compartment of the incoming / outgoing line cabinet to the digital device: one 32+1 core avionics cable (integrating all sampling signals); From the digital device to the station terminal: one avionics cable (for digital bus transmission of FT3 protocol data). This reduces the amount of cable used in the ring main unit by over 90%, significantly reducing cable usage, lowering wiring error rates, and saving materials and installation time. It also supports seamless capacity expansion. Traditional expansion methods require new cables to be routed through the cabinet, making the project complex. With this application, when adding new incoming / outgoing line cabinets, only the digital device needs to be connected to the same digital bus, without modifying the existing cable layout, achieving "plug-and-play" capacity expansion.

[0044] Third, achieve high-precision synchronous sampling and system integration. In the digital device provided in this application, cross-cabinet synchronization is achieved through the timing calibration mechanism of the FT3 protocol, which enables multi-cabinet synchronous sampling technology. The station terminal sends a frame header 0564H as a synchronization trigger signal. Each digital device adjusts the sampling start time with a delay time scale of 0.01μs resolution. Ultimately, the consistency of the current sampling angle difference of multiple bay cabinets is achieved within ±2 minutes, which not only meets the protection level accuracy requirements, but also provides the station terminal with synchronized voltage (PT cabinet) and current (bay cabinet) digital signals, supporting high-precision fault analysis.

[0045] Furthermore, this application integrates four major functions—sampling, display, control, and communication—into a single device. Local display includes voltage / current / temperature / humidity / switch status; local operation supports on-site opening and closing of circuit breakers; and a hard-plate protection lock. Remote interaction involves receiving remote control commands from the station terminal via a digital bus. This integrated functionality replaces traditionally distributed secondary equipment (such as independent indicating instruments and operating buttons), reducing potential points of failure.

[0046] Secondly, this application provides a ring main unit electrical signal digitization system, including a station terminal and a ring main unit electrical signal digitization device as described in any of the above embodiments. The station terminal communicates with the ring main unit electrical signal digitization device through the interface communication module.

[0047] Thirdly, embodiments of this application provide a ring main unit, including a station terminal and a ring main unit electrical signal digitization device as described in any of the preceding embodiments. The digitization device of this application adopts a cast aluminum molding structure, such as... Figure 6 and Figure 8 As shown, the front panel, from top to bottom, consists of an LCD panel displaying voltage, current, temperature, humidity, remote signaling status, operation indicator, alarm indicator, communication indicator, three-phase energized indicator, trip, close, and no-energy-store indicator, reset and reset buttons, trip and close buttons, remote and local buttons, and a 4-channel protection pressure plate. The back panel features a 6-channel aviation connector and a 32+1 pin aviation connector. All buttons, displays, and connection devices use IP67-rated components, and the entire unit has an IP67 protection rating.

[0048] The ring main unit provided in this application embodiment, with its cast aluminum shell and IP67 protection rating (all interfaces are aviation-grade plug-in type), can withstand the humid and dusty environment inside the ring main unit, achieving a high protection level design and enhancing environmental adaptability and ease of operation and maintenance. Furthermore, through a modular interchangeable design, the device is factory calibrated, and field replacement requires no re-adjustment; it can be directly interchanged and installed. Anomalies can be quickly located via panel indicator lights (operation / alarm / communication) and an LCD screen. In local mode, the opening and closing buttons can be directly operated, reducing reliance on station terminals and improving maintenance efficiency.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A ring main unit electrical signal digitization device, characterized in that, The digital device is installed in the secondary compartment of the incoming and outgoing line cabinets of the ring main unit, and includes a signal processing circuit, a display and interaction module, an interface communication module, a microprocessor, and a control circuit; wherein, The interface communication module includes a first flight connector and a second flight connector; The signal processing loop is connected to the primary compartment of the incoming / outgoing line cabinet via the first aviation connector, and is used to collect the operating status signal of the incoming / outgoing line cabinet and perform digital processing to generate digital operating data and send it to the microprocessor. The display and interaction module is connected to the microprocessor and the control loop respectively, and is used to receive and display the digital operation data through the microprocessor, and to obtain and output the user's manual operation commands to the control loop. The microprocessor is connected to the station terminal via the second navigation cable and is used to receive control commands and operating status signals, process the operating status signals according to the control commands, or control the operation of the signal processing loop, display and interaction module, receiving and decoding loop, encoding uplink loop or control loop according to the control commands. The control circuit is connected to the display and interaction module and the microprocessor respectively, and is used to drive the circuit breaker of the incoming and outgoing line cabinet to open or close according to the control command or manual operation command.

2. The ring main unit electrical signal digitization device according to claim 1, characterized in that, The microprocessor includes an uplink encoding loop, an MCU, and a downlink encoding loop; wherein... The encoding uplink loop is used to encode the digital running data according to a preset format, generate uplink frame data, and send it to the station terminal. The receiving and decoding circuit is used to receive downlink frame data sent by the station terminal, perform decoding processing, generate frame data, and send it to the microprocessor; The MCU is used to convert or process the digital operating data and output it to the display and interaction module, and to parse the frame data to obtain the control instructions and execute them.

3. The ring main unit electrical signal digitization device according to claim 2, characterized in that, The uplink and downlink communication between the receiving decoding circuit, the encoding uplink circuit and the station terminal all adopt the timing-based FT3 protocol, and the frame data structure includes a sampling delay time stamp and a preset frame header; The microprocessor is also used to send uplink frame data to the station terminal according to the sampling delay time stamp after the received frame data contains the preset frame header; the uplink frame data is used to realize the sampling synchronization of the PT cabinet voltage signal and the electrical signals in the incoming and outgoing line cabinets.

4. The ring main unit electrical signal digitization device according to claim 1, characterized in that, The signal processing loop includes a signal sampling interface, an isolation circuit, and a signal processing circuit; wherein... The signal sampling interface is used to receive the operating status signal and send it to the signal processing circuit; The isolation circuit is used to achieve signal transmission and power isolation; The signal processing circuit is used to amplify and convert the operating status signal to obtain the digital operating data.

5. The ring main unit electrical signal digitization device according to claim 1, characterized in that, The display and interaction module includes a data display module, an operation button module, and a warning indication module; wherein... The data display module is used to present the digital operating data to the user; The operation button module is used to manually control the control circuit of the incoming and outgoing line cabinet; The warning indication module is used to issue a warning signal to the user when there is an abnormality in the line in the ring main unit.

6. The ring main unit electrical signal digitization device according to claim 1, characterized in that, The receiving and decoding circuit includes a first protection circuit, a first 485 high-speed chip, and an FPGA decoding chip connected in series. The first protection circuit is used to protect the integrity of the signal during transmission; The first 485 high-speed chip is used to convert the differential voltage signal of the A / B lines into Manchester encoded data; The FPGA decoding chip is used to convert the received Manchester-encoded data into digital signals.

7. The ring main unit electrical signal digitization device according to claim 1, characterized in that, The encoding uplink circuit includes an XOR logic gate, a capacitor isolation chip, a second 485 high-speed chip, and a second protection circuit connected in series. The XOR logic gate is used to convert the digital running data into Manchester encoded data; The capacitor isolation chip is used to transmit digital signals through capacitive coupling, ensuring electrical isolation between communication and the main circuit. The second 485 high-speed chip is used to convert Manchester encoded data into A / B line differential voltage signals; The second protection circuit is used to protect the integrity of the signal.

8. The ring main unit electrical signal digitization device according to claim 1, characterized in that, The control loop includes: The energy storage control circuit is used to control the on / off state of the energy storage relay, thereby controlling the energy stored in the motor. The open / closed position indicator control circuit is used to control the on / off state of the open / closed position indicator light to display the open / closed status of the circuit breaker. The protection relay control circuit is used to control the on / off state of the protection opening and closing relays; The remote control circuit for opening and closing the circuit breaker is used to control the remote opening and closing operation. The local opening and closing control circuit is used to control the local opening and closing operations; The opening and closing holding control circuit is used to control the opening and closing holding relay to close and hold until the opening and closing action is completed.

9. A ring main unit electrical signal digitization system, characterized in that, It includes a station terminal and a ring main unit electrical signal digitization device as described in any one of claims 1-8, wherein the station terminal communicates with the ring main unit electrical signal digitization device through the interface communication module.

10. A ring main unit, characterized in that, Includes the ring main unit electrical signal digitization device as described in any one of claims 1-8.

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