Event-driven intelligent ring main unit and control method

Abstract

The invention relates to the field of ring main units, in particular to an event-driven intelligent ring main unit and a control method, and the event-driven intelligent ring main unit comprises a cabinet body, a cabinet body built-in circuit breaker, an isolation grounding switch and a fusion sensing array. An array synchronously acquires mechanical and electrical quantities, an edge decision-making system takes a voltage zero crossing point as an absolute time mark nanosecond alignment event, a closed-loop control core generates a protection and topology reconstruction instruction in situ according to the event, and primary equipment is driven in a millisecond level; the intelligent communication interface dynamically schedules bandwidth according to the data priority, and key instructions are ensured to be issued in real time. According to the invention, the problems of fault misjudgment and local control delay caused by lack of a unified time sequence reference in a mechanical state and an electrical transient state of a traditional ring main unit are solved.

Description

Technical Field

[0001] The present invention relates to the field of ring main unit (RMU), and in particular to an event-driven intelligent RMU and a control method thereof. Background Art

[0002] Although traditional ring main units (RMUs) can collect electrical and environmental quantities through transformers, temperature / humidity / smoke sensors, and high-frequency partial discharge probes, and upload the data to a master station via GPRS or optical fiber, their control chain adopts a centralized architecture of "collection-remote transmission-cloud decision-making-dispatching and execution," resulting in three inherent flaws. First, mechanical state quantities (such as contact travel and switch angle) and electrical transient quantities are independent of each other on a time basis. The master station simply compares these quantities based on their respective timestamps, making it difficult to accurately locate the causal relationship between mechanical faults such as delayed opening and closing operations and refusal to operate, and short circuits and ground faults with millisecond-level accuracy. Second, the round-trip latency between centralized cloud-based computing and command issuance is significant. When the RMU needs to perform protection blocking or topology reconstruction locally, it can easily miss the optimal action window of hundreds of milliseconds. Third, communication bandwidth is allocated according to fixed priority, and urgent control commands are often delayed due to non-critical data occupying the channel. The microcomputer protection ring main unit proposed in CN108448724A also fails to solve the above-mentioned timing mismatch and real-time problems. Therefore, there is an urgent need for a ring main unit architecture that can locally complete high-precision synchronization of mechanical and electrical events and perform closed-loop execution on-site. Summary of the Invention

[0003] The purpose of the present invention is to provide an event-driven intelligent ring main unit and control method to solve the problems of fault misjudgment and local control delay caused by the lack of a unified timing reference for mechanical state and electrical transient state in traditional ring main units.

[0004] To achieve the above objectives, the following technical solutions are adopted.

[0005] An event-driven intelligent ring network cabinet, comprising: Cabinet; A circuit breaker unit and an isolating and grounding switch unit are arranged in the cabinet; A fusion sensor array for collecting in real time the mechanical state parameters of the circuit breaker unit and the isolating and grounding switch unit, as well as the electrical parameters of the busbar and feeder in the cabinet; an edge decision-making system, communicatively connected to the fusion sensor array; The edge decision system includes: The time-space synchronization unit is used to receive the data collected by the fusion sensor array and use the electrical voltage parameter as a reference to Time synchronization between mechanical state change events and electrical transient processes; A closed-loop control core generates protection control instructions and / or topology reconstruction strategy instructions for the circuit breaker unit and / or the isolation and grounding switch unit based on the fused data aligned by the time-space synchronization unit, and executes them locally; An intelligent communication interface is connected to the edge decision system for communicating with the upper-level system and is provided with a data priority scheduler for dynamically allocating upload bandwidth according to the criticality of the data, giving priority to ensuring the real-time issuance of the protection control instructions and topology reconstruction strategy instructions.

[0006] Optionally, the fusion sensor array includes a mechanical state sensing module, an electrical parameter acquisition module and a signal processing unit; The mechanical state sensing module includes: The displacement sensor deployed inside the circuit breaker operating mechanism is used to monitor the linear motion of the moving contact in real time; Angle sensor installed on the rotating shaft of the isolating earthing switch is used to detect the opening and closing rotation angle of the knife switch; Distributed temperature sensors placed on the surface of the cable connector are used to collect the temperature field distribution at the contact point; The electrical parameter acquisition module includes: A capacitor voltage divider type voltage sensor connected in parallel to the busbar is used to obtain the three-phase voltage waveform; Rogowski coil current sensor wrapped around the feeder conductor to measure load current and short-circuit current; a broadband current detector coupled to the ground conductor path for capturing ground fault transient signals; The signal processing unit is integrated locally in the sensor array, and performs synchronous conditioning and analog-to-digital conversion on mechanical displacement, rotation angle, temperature, voltage, current and grounding signals, and outputs them to the edge decision system through a unified communication interface.

[0007] Optionally, the space-time synchronization unit includes a reference clock generation module, a clock distribution network and a time stamp embedding module; The reference clock generation module is connected to the voltage signal output terminal of the electrical parameter acquisition module, and generates a unified absolute time scale reference signal for the entire network by capturing voltage zero-crossing events in real time; The clock distribution network is constructed using a deterministic Ethernet protocol to transmit the absolute time reference signal to each sensor node in the fusion sensor array and the data processing unit of the edge decision system in a hardware-level synchronous manner; The time stamp embedding module is integrated into the data stream processing link and performs the following operations: For the displacement, angle and temperature data streams output by the mechanical state sensing module, corresponding time stamps are embedded when a state transition event is detected; For the voltage waveform, current waveform and ground signal output by the electrical parameter acquisition module, the corresponding time stamp is embedded when the starting point of the transient process is identified; The time scale sequences of mechanical state change events and electrical transient processes are aligned based on the absolute time scale reference, and a synchronous data stream is generated and output to the closed-loop control core.

[0008] Optionally, the closed-loop control core includes a fault diagnosis unit, a protection strategy generation unit and an instruction execution unit; The fault diagnosis unit is connected to the output end of the time-space synchronization unit, receives the time-aligned fusion data stream, and performs the following processing: Based on the time-scale correlation between the mechanical displacement sequence and the current waveform mutation, the circuit breaker opening and closing action delay or stagnation is identified; According to the synchronous relationship between the rotation angle change trajectory of the knife switch and the transient signal of the grounding current, it is judged that the isolation grounding switch has poor contact or refuses to operate; Combine the temperature distribution trend of the cable joint with the load current fluctuation to detect abnormal increase in contact resistance; The protection strategy generation unit is connected to the output end of the fault diagnosis unit and generates corresponding instructions according to the fault type: When an abnormal circuit breaker operation is identified, a tripping and locking instruction and a standby circuit breaker switching sequence are generated; When it is determined that the isolation grounding switch refuses to operate or has poor contact, a grounding fault isolation instruction and a load transfer path for adjacent ring network cabinets are generated; When abnormal contact resistance is detected, an overload warning instruction and current limit adjustment parameters are generated; The instruction execution unit is directly connected to the control loop of the circuit breaker unit and the isolation grounding switch unit through hard wiring, converts the protection control instruction and the topology reconstruction strategy into a drive signal, and executes the operation in real time.

[0009] An event-driven intelligent ring main unit control method includes the following steps: S1: The fusion sensor array synchronously collects the displacement characteristics of the circuit breaker's moving contact, the angle trajectory of the isolation switch, and the temperature distribution of the cable joint. It also captures the busbar voltage waveform, feeder current transient, and grounding signal spectrum. The signal processing unit interweaves and encodes the mechanical and electrical parameters to generate a fusion data stream. S2, the time-space synchronization unit generates an absolute time stamp based on the bus voltage zero-crossing point, injects time stamps into mechanical motion direction reversal events, switch torque mutation events, current rate of change exceeding the limit events, and grounding high-frequency energy burst events, and outputs a strictly aligned event sequence stream; S3. The fault diagnosis unit analyzes the event sequence flow, identifies mechanical response failures through the time-scale offset between displacement events and short-circuit current events, marks mechanism overheating by combining the change in temperature rise rate during the hysteresis period, determines switch lockout failure through the time-series misalignment between the switch angle event and the ground signal disappearance event, and tracks harmonic evolution to mark ferromagnetic resonance. S4. The protection strategy generation unit generates circuit breaker locking and cooling instructions for the mechanism overheating flag, and generates grounding reconfiguration and detuning instructions for the ferromagnetic resonance flag. The instructions are virtually executed in the digital mirror and supplementary diagnosis is triggered based on the simulation results. S5. The instruction execution unit executes the circuit breaker locking instruction through the millisecond channel and executes the detuning sequence through the second channel. At the same time, the data priority scheduler pre-occupies the instruction bandwidth and compresses non-critical data during supplementary diagnosis.

[0010] Optionally, the specific steps of step S1 include: S11. The displacement sensor of the mechanical state sensing module collects the original displacement signal of the circuit breaker moving contact in real time, the angle sensor synchronously collects the original rotation angle signal of the isolation switch, and the distributed temperature sensor obtains the temperature distribution matrix of the cable connector surface; S12. The voltage sensor of the electrical parameter acquisition module captures the original data of the busbar three-phase voltage waveform, the current sensor obtains the original data of the feeder current transient waveform, and the broadband detector extracts the high-frequency transient signal of the grounding conductor; S13, the signal processing unit receives the original displacement signal and the original rotation angle signal, calculates the instantaneous velocity vector of the moving contact and the angular acceleration vector of the knife switch through the kinematic model, and simultaneously performs spatial grid processing on the temperature distribution matrix to generate a temperature gradient vector; S14. The signal processing unit performs fundamental frequency period resampling on the busbar three-phase voltage waveform to eliminate spectrum leakage, performs synchronous resampling on the feeder current transient waveform, and extracts the wavelet packet energy coefficient of a preset characteristic frequency band from the grounding high-frequency transient signal; S15. Using the zero-crossing event of the instantaneous velocity vector of the moving contact as a trigger condition, intercept the bus voltage harmonic distortion rate data of the corresponding time window; using the knife switch angular acceleration vector exceeding the preset threshold as a trigger condition, correlate and extract the sudden change amplitude of the grounding wavelet packet energy coefficient; S16. Interweave and encode the time-aligned mechanical dynamic feature vector including instantaneous velocity, angular acceleration, and temperature gradient with the electrical feature vector including voltage harmonic distortion rate, resampled current waveform, and wavelet packet energy mutation amplitude into a fused data stream and output it to the spatiotemporal synchronization unit.

[0011] Optionally, the specific steps of step S2 include: S21, the reference clock generation module captures the voltage zero-crossing event from the bus voltage waveform and generates a unified absolute time-scale reference signal for the entire network; S22, the clock distribution network transmits the absolute time reference signal to each sensor node of the fusion sensor array and the data processing unit of the edge decision system in a hardware-level synchronous manner through the deterministic Ethernet protocol; S23. The time-stamp embedding module monitors the output signal of the mechanical state sensing module in real time. When a reversal feature of the moving contact displacement direction is detected, it is marked as a mechanical movement direction reversal event. When the second-order derivative of the knife switch angle change exceeds the dynamic threshold, it is marked as a knife switch torque mutation event. S24. The time-stamp embedding module synchronously monitors the output signal of the electrical parameter acquisition module. When the feeder current change rate exceeds the safety envelope, it is marked as a current change rate exceeding limit event. When the wavelet energy of the grounding signal in the preset high frequency band undergoes a step mutation, it is marked as a grounding high frequency energy burst event. S25, for the mechanical and electrical events marked by S23 and S24, inject the absolute time stamp generated by S21 at the time of event occurrence to form an event tuple with a time stamp; S26. Sort all event tuples with time stamps according to the absolute time stamp, eliminate the timing misalignment caused by network transmission jitter, and generate a strictly aligned event sequence stream to output to the fault diagnosis unit.

[0012] Optionally, the specific steps of step S3 include: S31. The fault diagnosis unit extracts the occurrence time of the circuit breaker displacement event and the occurrence time of the associated short-circuit current event from the event sequence stream, calculates the time difference between the two, and outputs a mechanical response failure flag when the time difference exceeds a preset tolerance; S32. Based on the mechanical response failure mark output by S31, locate the specific time window after the displacement event, analyze the temperature rise rate change trend of the mechanism box temperature sensor within the window, and generate a mechanism overheat mark when the rise rate exceeds the dynamic threshold; S33, extracting the occurrence time of the knife switch angle event and the occurrence time of the ground signal disappearance event from the event sequence stream, determining the order of the two, and outputting a knife switch lock failure flag when the angle event disappears earlier than the ground signal disappears; S34, based on the switch lock failure flag output by S33, monitors the change in the proportion of the third harmonic component of the feeder current in a continuous time period after the angle event, and generates a ferromagnetic resonance flag when the proportion shows a continuous growth trend; S35, integrate the mechanical response failure mark of S31, the mechanism overheating mark of S32, the knife switch locking failure mark of S33 and the ferromagnetic resonance mark of S34 into a structured fault diagnosis result and output it to the protection strategy generation unit.

[0013] Optionally, the specific steps of step S4 include: S41: The protection strategy generation unit receives the mechanism overheat flag output by the fault diagnosis unit and generates a command group 1 including a circuit breaker locking command and a cooling fan start command; S42: The protection strategy generation unit receives the ferromagnetic resonance marker output by the fault diagnosis unit and generates a second instruction group including a grounding switch reorganization sequence and a detuning device activation sequence; S43: Load the current ring main unit status data into the digital mirror model of the edge decision system, and virtually execute the instruction group 1 generated by S41 and the instruction group 2 generated by S42 in sequence; S44: The digital mirror model monitors the system response after virtual execution: For instruction group 1, check whether the temperature rise rate of the mechanism box drops to the safety threshold; For instruction group 2, check whether the proportion of the third harmonic of the feeder current stops increasing; When any test fails to meet the standard, a supplementary diagnosis request is sent to the fault diagnosis unit; S45: Pack the instruction group 1 and the instruction group 2 that have passed the virtual verification into a strategy instruction package, and output it to the instruction execution unit.

[0014] Optionally, the specific steps of step S5 include: S51. The instruction execution unit receives the strategy instruction packet, activates the first execution channel directly connected to the circuit breaker unit in the circuit breaker locking instruction, outputs the opening drive signal with the highest response priority and locks the reclosing function; S52: Activate the second execution channel for the harmonic elimination device activation sequence, send activation instructions to the harmonic elimination device controller in stages according to a preset coordination sequence, and retain a status monitoring window between adjacent instructions; S53, when the protection strategy generation unit outputs the instruction, the data priority scheduler immediately allocates the highest priority communication bandwidth to the first execution channel and dynamically expands the bandwidth for the second execution channel; S54. When a supplementary diagnostic request is received, the periodic monitoring data is downgraded to a compressed transmission mode, and the released bandwidth resources are allocated to the virtual verification data stream; S55. After the instruction is executed, an execution message including the information of the locking state release, the operation state of the detuning device and the communication bandwidth recovery is generated and uploaded via the intelligent communication interface.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present application integrates a sensor array to simultaneously capture mechanical state parameters and electrical parameters in the same clock domain; the spatiotemporal synchronization unit in the edge decision system uses the electrical voltage zero crossing point as the absolute time scale reference to perform nanosecond alignment of mechanical events and electrical transient processes, thereby accurately locking the causal chain between mechanical anomalies such as action delay and refusal to operate and fault current and grounding transients; the closed-loop control core instantly generates protection control and topology reconstruction strategies based on the alignment results, and directly drives the circuit breaker unit and the isolation grounding switch unit to achieve millisecond-level on-site action; the intelligent communication interface ensures that key instructions always occupy the highest bandwidth through the data priority scheduler, further shortening the response time. Therefore, the primary beneficial effect is: without relying on the cloud, the ring network cabinet can complete high-reliability, low-latency protection and reconstruction on-site based on the time alignment results of mechanical-electrical events, completely eliminating misjudgments and delays caused by timing mismatch.

[0016] The above effects are enhanced through hardware modular design: the fused sensor array integrates various sensors and signal processing units on the same physical layer, avoiding the signal delay and phase drift caused by the cascading of multiple devices in traditional solutions; the time and space synchronization unit adopts deterministic Ethernet hardware-level distribution time stamp to ensure that each sensor node and the edge decision system share the same clock reference, eliminating the interference of network jitter on timing alignment at the protocol level; the closed-loop control core is based on the aligned fused data, completing the fault type identification locally and directly generating strategies such as circuit breaker locking and load transfer, shortening the "perception-decision-execution" link from the system architecture, so that the ring network cabinet can perform closed-loop actions on site without waiting for cloud feedback.

[0017] This application solidifies the above technical advantages from the perspective of method flow: Steps S1-S2 use "interleaved coding" to bind mechanical dynamic features and electrical features into the same data stream, ensuring that the two always share the same time axis in subsequent processing; Steps S3-S4 use logical rules such as time scale offset and harmonic evolution to convert the distinction between mechanical failure and electrical failure into reproducible mathematical conditions from the algorithm level; Step S5 reserves bandwidth for emergency instructions through a priority scheduler, ensuring the real-time performance of key control signals from the perspective of resource scheduling. In summary, the entire technical solution overcomes the misjudgment and delay problems caused by timing mismatch and cloud dependence in the background technology in principle through the hierarchical design of "clock unification-data fusion-local closed loop", so that the ring network cabinet has higher action reliability and autonomy in fault scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the module structure of an event-driven intelligent ring network cabinet embodiment according to the present invention.

[0019] Figure 2The figure is a flowchart of the steps of an embodiment of an event-driven intelligent ring main unit control method according to the present invention. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0021] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0022] Example 1

[0023] like Figure 1 As shown, this embodiment discloses an event-driven intelligent ring network cabinet that can be directly deployed on the ground. The cabinet body can be made of cold-rolled steel plates that are bent and then welded as a whole. The outer surface is sprayed with plastic with a thickness of not less than 80 μm. The interior is longitudinally divided into three compartments: front, middle, and rear compartments by three epoxy insulation partitions. A vacuum circuit breaker unit is installed on the top of the front compartment. The circuit breaker pole is a sealed pole, vacuum-cast with epoxy resin. The linear motion stroke of the moving contact is monitored in real time by an LVDT displacement sensor installed inside the operating mechanism. The displacement sensor housing is fixed to the top of the mechanism box by an M5 stainless steel bracket. The operating mechanism is a permanent magnet-spring composite mechanism. The permanent magnet is locked to the side plate of the mechanism by screws. The spring is a cylindrical helical compression spring, which is connected to the mechanism connecting rod through a guide sleeve. The isolating and grounding switch unit is located in the middle cabin. The knife switch has a double-pole double-throw structure. The end face of the rotating shaft is machined with a D-shaped flat position. The rotary encoder of the angle sensor is coaxially installed with the knife switch shaft through a D-shaped shaft sleeve. The encoder body is fixed to the isolation cover through an aluminum alloy bracket; a cable connector is set under the knife switch, and a distributed optical fiber temperature sensor is pasted on the surface of the cable connector. The optical fiber is arranged in a serpentine shape and fixed with high-temperature resistant thermal conductive glue. The optical fiber pigtail is connected to the photoelectric conversion module of the signal processing unit through a flange.

[0024] The fused sensor array is housed in an aluminum shielded box, secured to the right column of the cabinet via DIN rail. The box is divided into three functional areas: mechanical state sensing, electrical parameter acquisition, and signal processing. The mechanical state sensing area includes displacement sensor conditioning circuitry, angle sensor conditioning circuitry, and a fiber-optic temperature measurement and demodulation module. The conditioning circuitry outputs a 0-5 V analog signal. The electrical parameter acquisition area includes a capacitive voltage divider, a Rogowski coil current sensor, and a broadband current detector. The voltage sensor input is connected in parallel to the busbar via a high-voltage cable, and the output is connected to an isolation amplifier via a coaxial cable. The Rogowski coil is a flexible open-ended structure that fits over the feeder conductor and connects to an integrator via a BNC connector. The broadband current detector is a clamp-type open-ended structure that clamps onto the ground conductor and connects to a broadband preamplifier. The core of the signal processing area is a low-power microcontroller (MCU). The MCU synchronously samples analog signals using a multi-channel ADC and performs analog-to-digital conversion, digital filtering, and data packaging locally. The packaged data is then transmitted to the edge decision-making system via a unified RS-485 or Ethernet interface.

[0025] The edge decision system consists of three circuit boards: a power supply board, a main control board, and a communications board. All are housed in a 6U, 19-inch chassis secured to the cabinet's bottom crossbar with shock-absorbing pads. The power supply board takes a 220 V AC input and outputs multiple isolated power supplies, including 24 V, 12 V, and 5 V. The main control board is based on an industrial-grade ARM processor, with external DDR memory and eMMC storage, and runs the Linux real-time kernel. The communications board integrates two Gigabit Ethernet PHYs and one RS-485 transceiver, and has a reserved Mini-PCIe slot for 4G / 5G module expansion. The spatiotemporal synchronization unit on the main control board is implemented using an FPGA. A phase-locked loop (PLL) is instantiated within the FPGA. The PLL reference clock is derived from the bus voltage zero-crossing detection circuit, which consists of a precision zero-crossing comparator, an isolated optocoupler, and a Schmitt trigger. The comparator input is connected to the bus voltage sensor output via a voltage-divider resistor network. The output generates a pulse signal synchronized with the voltage zero-crossing. This pulse signal serves as a reference for the PLL, which outputs a 100 MHz global clock. This clock is distributed to each sensor node in the fused sensor array via a deterministic Ethernet PHY chip, achieving hardware-level synchronization. A time-stamp embedding module is also instantiated within the FPGA. This module monitors the data streams output by the mechanical state sensing module and the electrical parameter acquisition module. When a data transition or transient start occurs, the absolute time stamp generated by the PLL is inserted into the packet header, forming a time-stamped data frame.

[0026] The closed-loop control core resides on the main control board. The fault diagnosis unit is a real-time task running on an ARM processor. This task receives time-stamped data frames in a circular buffer and uses a sliding window algorithm to calculate the time delay between mechanical displacement and current mutation. If the time delay exceeds a set threshold, the "mechanical response failure" flag is set. Simultaneously, the task analyzes the relationship between the knife switch angle trajectory and the disappearance of the grounding signal. If the knife switch angle event occurs before the disappearance of the grounding signal, the "knife switch lockout failure" flag is set. The task also monitors the rate of change of the cable joint temperature gradient and sets the "contact resistance abnormality" flag if the rate of change exceeds a set threshold. The protection strategy generation unit is another real-time task that generates corresponding instructions based on the aforementioned flags. When the mechanical response failure flag is set, the task generates an instruction group containing the sequence for immediately opening the circuit breaker, locking the reclosing switch, and switching on the backup circuit breaker. When the knife switch lockout failure flag is set, the task generates an instruction group containing the sequence for immediately opening the grounding switch and calculating the load transfer path for adjacent ring main units. When the contact resistance abnormality flag is set, the task generates an instruction group containing an overload warning and a current limit reduction. The instruction execution unit is implemented through two sets of high-speed optocoupler isolated output channels: the first set of optocoupler outputs is directly connected to the circuit breaker trip coil circuit, with a contact capacity of 250 V / 8 A and a response time of <1 ms; the second set of optocoupler outputs is connected to the isolation grounding switch motor driver, with a contact capacity of 250 V / 5 A and a response time of <10 ms.

[0027] The intelligent communication interface is located on the communications board. Its core is an Ethernet switch chip that supports IEEE 1588. It features four levels of priority queues. Queue 0, the highest priority, is reserved for protection control commands and topology reconfiguration policy instructions. Queue 1 is reserved for fault event logs; Queue 2 is reserved for periodic status data; and Queue 3 is reserved for remote maintenance data. The data priority scheduler is implemented using the Linux tc flow control module. The module immediately reserves 80% of the uplink bandwidth for queue 0 upon policy instruction generation, dynamically adjusting the bandwidth for the remaining queues accordingly. When receiving supplemental diagnostic requests, the module compresses the data in queue 2 before sending it, freeing up bandwidth for the virtual verification data stream.

[0028] Example 2

[0029] like Figure 2 As shown, this embodiment provides an event-driven intelligent ring network cabinet control method based on the hardware platform of Example 1. The entire process runs in the embedded Linux real-time kernel of the edge decision system, all key threads are bound to the dedicated CPU core, and the clock source is synchronized with the bus voltage zero crossing point to ensure sub-millisecond determinism.

[0030] S1. The fused sensor array synchronously collects mechanical and electrical parameters, interleaving and encoding them to generate a fused data stream. Specifically, upon system power-up, the fused sensor array first performs a self-zero calibration: the displacement sensor records the zero point of the actuator's no-load displacement in the no-current state, the angle sensor records the zero point of the angle when the knife switch is fully open, and the distributed temperature sensor collects a baseline thermal image of the cable connector at ambient temperature. A continuous sampling cycle then begins. The displacement sensor in the mechanical state sensing module outputs a raw displacement signal at a rate of 10 kHz. This signal undergoes a second-order analog anti-aliasing filter and is fed into the MCU's 16-bit ADC. The MCU internally runs a combined sliding average and Kalman filter algorithm to generate a smoothed displacement sequence. The instantaneous velocity vector is then calculated using two differentials. A velocity reversal event is recorded. The angle sensor uses a magnetoelectric absolute encoder, outputting angle values ​​every 0.1°. The MCU calculates the angular acceleration vector using a FIR differentiator. A torque mutation event is recorded when the angular acceleration exceeds an adaptive threshold. The threshold is dynamically updated by adding three times the variance to the mean of the previous cycle to accommodate varying ambient temperatures and lubrication conditions. The distributed temperature sensor is a fiber Bragg grating array. The MCU obtains the central wavelength matrix through tunable laser scanning, writes the wavelength-temperature calibration coefficient into the flash memory, and solves it into a temperature distribution matrix in real time. Then, a two-dimensional cubic convolution is performed to obtain the temperature gradient vector. In the electrical parameter acquisition module, the output of the capacitive voltage divider is driven by an isolation amplifier. The MCU synchronously samples at a rate 128 times the bus fundamental frequency, performs a 256-point FFT, extracts the fundamental and harmonic components, uses a window function to correct the amplitude, and calculates the harmonic distortion rate. The Rogowski coil current signal is restored by an integrator and sampled at the same rate. Wavelet packet decomposition is used to extract the energy coefficient of the preset characteristic frequency band. The output of the broadband current detector is divided into multiple sub-bands by a bandpass filter bank. The energy of each sub-band is sent to the MCU after envelope detection. When the energy of any sub-band suddenly changes, a high-frequency energy burst event is recorded. After obtaining the above-mentioned mechanical dynamic feature vectors and electrical feature vectors, the signal processing unit interleaves and encodes them according to the timestamp: based on the velocity zero crossing point, the electrical feature vectors in the 2 ms time window before and after are intercepted; based on the angular acceleration exceeding the limit, the ground wavelet energy mutation amplitude at the corresponding moment is intercepted; the mechanical and electrical features are spliced ​​into a 128-byte fixed-length fused data frame, which is sent to the edge decision system via a Gigabit Ethernet Raw Socket. The MAC layer adds an IEEE 1588PTP timestamp to ensure that it has a sub-microsecond time stamp before entering the space-time synchronization unit.

[0031] S2, the spatiotemporal synchronization unit, generates absolute time stamps based on the bus voltage zero crossings, injects event time stamps, and outputs an aligned event sequence stream. Specifically, the spatiotemporal synchronization unit's reference clock generation module is implemented within the FPGA. It first performs zero-crossing detection on the bus voltage sampling sequence. To avoid noise interference, a Schmitt trigger plus digital hysteresis algorithm is used. A zero crossing is confirmed only when three consecutive cycles cross zero in the same direction. The zero-crossing pulse drives a PLL to generate a 100 MHz synchronous clock with less than 50 ps of clock jitter. The clock distribution network consists of an IEEE 802.1AS-compliant TSN switch chip. The FPGA injects Sync messages into the switch chip via the RGMII interface. The switch chip uses hardware timestamps to correct the dwell time at the egress, ensuring synchronization of all sensor nodes within a ±100 ns error range. The time stamp embedding module parses the header timestamp of each fused data frame. If the timestamp deviates from the local clock by more than a threshold, the frame is discarded and retransmission is triggered. Simultaneously, when a mechanical state transition or electrical transient start point is detected, the frame is re-stamped based on the local clock to form an event tuple with an absolute time stamp. All event tuples are sorted in ascending order by absolute time stamp and written into a circular buffer. The buffer can accommodate event sequences of up to 200 ms for retrieval by the fault diagnosis unit.

[0032] S3. The fault diagnosis unit parses the event sequence stream, identifying and flagging mechanical response failure, mechanism overheating, switch lockout failure, and ferroresonance. Specifically, the fault diagnosis unit runs as a real-time thread with higher priority than ordinary tasks. It uses a zero-copy mechanism to retrieve event sequences directly from a ring buffer. The thread first establishes an event association table: using the circuit breaker displacement event as the key, it searches for short-circuit current events within the same millisecond window and calculates the time difference between them. The time difference threshold is the circuit breaker's rated opening time plus the allowable deviation. If the threshold is exceeded, the mechanical response failure flag is set. The thread then searches for changes in the mechanism box temperature gradient within the subsequent 10 ms window. If the temperature rise rate exceeds the dynamic threshold, the mechanism overheat flag is added. For switch angle events, the thread searches for a ground signal loss event within the subsequent 5 ms. If so, and the angle event precedes it, the switch lockout failure flag is set. The thread further monitors the third harmonic component of the feeder current. If the proportion continues to increase, the ferroresonance flag is added. All flags are written to shared memory as structures for retrieval by the protection strategy generation unit. The shared memory uses a double buffering mechanism to ensure lock-free read and write concurrency.

[0033] S4. The protection strategy generation unit generates locking, cooling or grounding reorganization, and detuning instructions based on the mark, executes them virtually in the digital mirror, and triggers supplementary diagnosis. Specifically, after receiving the fault mark, the protection strategy generation unit immediately calls the strategy function library: if there is a mechanism overheating mark, the function library generates a circuit breaker locking command and a cooling fan start-up command. The command is a 16-byte binary frame, including the target device ID, operation code, action delay, and check code. The frame format complies with the IEC 61850 GOOSE fast message specification; if there is a ferromagnetic resonance mark, a grounding switch reorganization sequence and a detuning device input sequence are generated. Each step in the sequence includes execution conditions, delays, and readback checks. The policy library writes the generated instruction groups into a digital mirror model—a high-fidelity digital twin of the ring main unit (RMU), built with Simscape Electrical and running on an edge GPU. The model synchronizes the system state in real time and predicts the evolution of busbar voltage, current, and temperature distribution by virtually executing the instruction groups. If the simulation results meet safety constraints, the instruction group is marked as "executable." Otherwise, a supplementary diagnostic request is sent to the fault diagnosis unit, accompanied by a simulation difference value for threshold adjustment. Verified instruction groups are packaged into policy instruction packets and distributed over the RTNet real-time network.

[0034] S5. The instruction execution unit executes instructions according to the millisecond / second channel, and the data priority scheduler dynamically compresses non-critical data. Specifically, after receiving the strategy instruction package, the instruction execution unit selects the execution channel according to the instruction type: the circuit breaker locking instruction directly drives the trip coil through the first execution channel. The channel consists of a high-speed optocoupler, MOSFET and varistor. The MOSFET gate is controlled by the FPGA hardware PWM, which can complete the coil power-on and lock the reclosing logic within 1 ms; the harmonic elimination device input sequence is issued through the second execution channel. The channel uses the RS-485 Modbus RTU protocol. The edge decision system acts as the master station and sends write register commands to multiple harmonic elimination devices according to the preset coordination sequence. Adjacent commands are separated by 100 ms and a status query frame is inserted to confirm that the previous step has been executed. The data priority scheduler utilizes Linux tc's HTB queue. When a policy instruction packet is generated, the scheduler immediately reserves the highest priority queue for GOOSE messages, occupying 80% of the bandwidth. The remaining bandwidth is shared between periodic monitoring and maintenance data. When a supplemental diagnostic request is received, the scheduler compresses the periodic data into gzip format, reducing its transmission frequency. The freed-up bandwidth is used for virtual verification data streams, ensuring real-time policy iteration. After the instruction is executed, the edge decision system generates an execution message containing the lock status, detuning device operating status, communication bandwidth utilization, CPU load, and memory usage. This message is uploaded to the upper-level SCADA system via the MQTT protocol and the intelligent communication interface. It is also written locally to a SQLite database for post-mortem and big data analysis.

[0035] It is understood from common technical knowledge that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, merely illustrative and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

Claims

1. An event-driven intelligent ring main unit, characterized in that: include, Cabinet; A circuit breaker unit and an isolating and grounding switch unit are arranged in the cabinet; A fusion sensor array for collecting in real time the mechanical state parameters of the circuit breaker unit and the isolating and grounding switch unit, as well as the electrical parameters of the busbar and feeder in the cabinet; an edge decision-making system, communicatively connected to the fusion sensor array; The edge decision system includes: The time-space synchronization unit is used to receive the data collected by the fusion sensor array and use the electrical voltage parameter as a reference to Time synchronization between mechanical state change events and electrical transient processes; A closed-loop control core generates protection control instructions and / or topology reconstruction strategy instructions for the circuit breaker unit and / or the isolation and grounding switch unit based on the fused data aligned by the time-space synchronization unit, and executes them locally; An intelligent communication interface is connected to the edge decision system for communicating with the upper-level system and is provided with a data priority scheduler for dynamically allocating upload bandwidth according to the criticality of the data, giving priority to ensuring the real-time issuance of the protection control instructions and topology reconstruction strategy instructions.

2. The event-driven intelligent ring main unit according to claim 1, characterized in that: The fusion sensor array includes a mechanical state sensing module, an electrical parameter acquisition module and a signal processing unit; The mechanical state sensing module includes: The displacement sensor deployed inside the circuit breaker operating mechanism is used to monitor the linear motion of the moving contact in real time; Angle sensor installed on the rotating shaft of the isolating earthing switch is used to detect the opening and closing rotation angle of the knife switch; Distributed temperature sensors placed on the surface of the cable connector are used to collect the temperature field distribution at the contact point; The electrical parameter acquisition module includes: A capacitor voltage divider type voltage sensor connected in parallel to the busbar is used to obtain the three-phase voltage waveform; Rogowski coil current sensor wrapped around the feeder conductor to measure load current and short-circuit current; a broadband current detector coupled to the ground conductor path for capturing ground fault transient signals; The signal processing unit is integrated locally in the sensor array, and performs synchronous conditioning and analog-to-digital conversion on mechanical displacement, rotation angle, temperature, voltage, current and grounding signals, and outputs them to the edge decision system through a unified communication interface.

3. The event-driven intelligent ring main unit according to claim 1, characterized in that: The space-time synchronization unit includes a reference clock generation module, a clock distribution network and a time stamp embedding module; The reference clock generation module is connected to the voltage signal output terminal of the electrical parameter acquisition module, and generates a unified absolute time scale reference signal for the entire network by capturing voltage zero-crossing events in real time; The clock distribution network is constructed using a deterministic Ethernet protocol to transmit the absolute time reference signal to each sensor node in the fusion sensor array and the data processing unit of the edge decision system in a hardware-level synchronous manner; The time stamp embedding module is integrated into the data stream processing link and performs the following operations: For the displacement, angle and temperature data streams output by the mechanical state sensing module, corresponding time stamps are embedded when a state transition event is detected; For the voltage waveform, current waveform and ground signal output by the electrical parameter acquisition module, the corresponding time stamp is embedded when the starting point of the transient process is identified; The time scale sequences of mechanical state change events and electrical transient processes are aligned based on the absolute time scale reference, and a synchronous data stream is generated and output to the closed-loop control core.

4. The event-driven intelligent ring main unit according to claim 1, characterized in that: The closed-loop control core includes a fault diagnosis unit, a protection strategy generation unit and an instruction execution unit; The fault diagnosis unit is connected to the output end of the time-space synchronization unit, receives the time-aligned fusion data stream, and performs the following processing: Based on the time-scale correlation between the mechanical displacement sequence and the current waveform mutation, the circuit breaker opening and closing action delay or stagnation is identified; According to the synchronous relationship between the rotation angle change trajectory of the knife switch and the transient signal of the grounding current, it is judged that the isolation grounding switch has poor contact or refuses to operate; Combine the temperature distribution trend of the cable joint with the load current fluctuation to detect abnormal increase in contact resistance; The protection strategy generation unit is connected to the output end of the fault diagnosis unit and generates corresponding instructions according to the fault type: When an abnormal circuit breaker operation is identified, a tripping and locking instruction and a standby circuit breaker switching sequence are generated; When it is determined that the isolation grounding switch refuses to operate or has poor contact, a grounding fault isolation instruction and a load transfer path for adjacent ring network cabinets are generated; When abnormal contact resistance is detected, an overload warning instruction and current limit adjustment parameters are generated; The instruction execution unit is directly connected to the control loop of the circuit breaker unit and the isolation grounding switch unit through hard wiring, converts the protection control instruction and the topology reconstruction strategy into a drive signal, and executes the operation in real time.

5. An event-driven intelligent ring main unit control method, based on the event-driven intelligent ring main unit according to any one of claims 1 to 4, characterized in that: The following steps are included: S1: The fusion sensor array synchronously collects the displacement characteristics of the circuit breaker's moving contact, the angle trajectory of the isolation switch, and the temperature distribution of the cable joint. It also captures the busbar voltage waveform, feeder current transient, and grounding signal spectrum. The signal processing unit interweaves and encodes the mechanical and electrical parameters to generate a fusion data stream. S2, the time-space synchronization unit generates an absolute time stamp based on the bus voltage zero-crossing point, injects time stamps into mechanical motion direction reversal events, switch torque mutation events, current rate of change exceeding the limit events, and grounding high-frequency energy burst events, and outputs a strictly aligned event sequence stream; S3. The fault diagnosis unit analyzes the event sequence flow, identifies mechanical response failures through the time-scale offset between displacement events and short-circuit current events, marks mechanism overheating by combining the change in temperature rise rate during the hysteresis period, determines switch lockout failure through the time-series misalignment between the switch angle event and the ground signal disappearance event, and tracks harmonic evolution to mark ferromagnetic resonance. S4. The protection strategy generation unit generates circuit breaker locking and cooling instructions for the mechanism overheating flag, and generates grounding reconfiguration and detuning instructions for the ferromagnetic resonance flag. The instructions are virtually executed in the digital mirror and supplementary diagnosis is triggered based on the simulation results. S5. The instruction execution unit executes the circuit breaker locking instruction through the millisecond channel and executes the detuning sequence through the second channel. At the same time, the data priority scheduler pre-occupies the instruction bandwidth and compresses non-critical data during supplementary diagnosis.

6. The event-driven intelligent ring main unit control method according to claim 5, characterized in that: The specific steps of step S1 include: S11. The displacement sensor of the mechanical state sensing module collects the original displacement signal of the circuit breaker moving contact in real time, the angle sensor synchronously collects the original rotation angle signal of the isolation switch, and the distributed temperature sensor obtains the temperature distribution matrix of the cable connector surface; S12. The voltage sensor of the electrical parameter acquisition module captures the original data of the busbar three-phase voltage waveform, the current sensor obtains the original data of the feeder current transient waveform, and the broadband detector extracts the high-frequency transient signal of the grounding conductor; S13, the signal processing unit receives the original displacement signal and the original rotation angle signal, calculates the instantaneous velocity vector of the moving contact and the angular acceleration vector of the knife switch through the kinematic model, and simultaneously performs spatial grid processing on the temperature distribution matrix to generate a temperature gradient vector; S14. The signal processing unit performs fundamental frequency period resampling on the busbar three-phase voltage waveform to eliminate spectrum leakage, performs synchronous resampling on the feeder current transient waveform, and extracts the wavelet packet energy coefficient of a preset characteristic frequency band from the grounding high-frequency transient signal; S15. Using the zero-crossing event of the instantaneous velocity vector of the moving contact as a trigger condition, intercept the bus voltage harmonic distortion rate data of the corresponding time window; using the knife switch angular acceleration vector exceeding the preset threshold as a trigger condition, correlate and extract the sudden change amplitude of the grounding wavelet packet energy coefficient; S16. Interweave and encode the time-aligned mechanical dynamic feature vector including instantaneous velocity, angular acceleration, and temperature gradient with the electrical feature vector including voltage harmonic distortion rate, resampled current waveform, and wavelet packet energy mutation amplitude into a fused data stream and output it to the spatiotemporal synchronization unit.

7. The event-driven intelligent ring main unit control method according to claim 5 is characterized in that The specific steps of step S2 are: include, S21, the reference clock generation module captures the voltage zero-crossing event from the bus voltage waveform and generates a unified absolute time-scale reference signal for the entire network; S22, the clock distribution network transmits the absolute time reference signal to each sensor node of the fusion sensor array and the data processing unit of the edge decision system in a hardware-level synchronous manner through the deterministic Ethernet protocol; S23. The time-stamp embedding module monitors the output signal of the mechanical state sensing module in real time. When a reversal feature of the moving contact displacement direction is detected, it is marked as a mechanical movement direction reversal event. When the second-order derivative of the knife switch angle change exceeds the dynamic threshold, it is marked as a knife switch torque mutation event. S24. The time-stamp embedding module synchronously monitors the output signal of the electrical parameter acquisition module. When the feeder current change rate exceeds the safety envelope, it is marked as a current change rate exceeding limit event. When the wavelet energy of the grounding signal in the preset high frequency band undergoes a step mutation, it is marked as a grounding high frequency energy burst event. S25, for the mechanical and electrical events marked by S23 and S24, inject the absolute time stamp generated by S21 at the time of event occurrence to form an event tuple with a time stamp; S26. Sort all event tuples with time stamps according to the absolute time stamp, eliminate the timing misalignment caused by network transmission jitter, and generate a strictly aligned event sequence stream to output to the fault diagnosis unit.

8. The event-driven intelligent ring main unit control method according to claim 5, characterized in that: The specific steps of step S3 are: include, S31. The fault diagnosis unit extracts the occurrence time of the circuit breaker displacement event and the occurrence time of the associated short-circuit current event from the event sequence stream, calculates the time difference between the two, and outputs a mechanical response failure flag when the time difference exceeds a preset tolerance; S32. Based on the mechanical response failure mark output by S31, locate the specific time window after the displacement event, analyze the temperature rise rate change trend of the mechanism box temperature sensor within the window, and generate a mechanism overheat mark when the rise rate exceeds the dynamic threshold; S33, extracting the occurrence time of the knife switch angle event and the occurrence time of the ground signal disappearance event from the event sequence stream, determining the order of the two, and outputting a knife switch lock failure flag when the angle event disappears earlier than the ground signal disappears; S34, based on the switch lock failure flag output by S33, monitors the change in the proportion of the third harmonic component of the feeder current in a continuous time period after the angle event, and generates a ferromagnetic resonance flag when the proportion shows a continuous growth trend; S35, integrate the mechanical response failure mark of S31, the mechanism overheating mark of S32, the knife switch locking failure mark of S33 and the ferromagnetic resonance mark of S34 into a structured fault diagnosis result and output it to the protection strategy generation unit.

9. The event-driven intelligent ring main unit control method according to claim 5, characterized in that: The specific steps of step S4 include: S41: The protection strategy generation unit receives the mechanism overheat flag output by the fault diagnosis unit and generates a command group 1 including a circuit breaker locking command and a cooling fan start command; S42: The protection strategy generation unit receives the ferromagnetic resonance marker output by the fault diagnosis unit and generates a second instruction group including a grounding switch reorganization sequence and a detuning device activation sequence; S43: Load the current ring main unit status data into the digital mirror model of the edge decision system, and virtually execute the instruction group 1 generated by S41 and the instruction group 2 generated by S42 in sequence; S44: The digital mirror model monitors the system response after virtual execution: For instruction group 1, check whether the temperature rise rate of the mechanism box drops to the safety threshold; For instruction group 2, check whether the proportion of the third harmonic of the feeder current stops increasing; When any test fails to meet the standard, a supplementary diagnosis request is sent to the fault diagnosis unit; S45: Pack the instruction group 1 and the instruction group 2 that have passed the virtual verification into a strategy instruction package, and output it to the instruction execution unit.

10. The event-driven intelligent ring main unit control method according to claim 5, characterized in that: The specific steps of step S5 are: include, S51: The instruction execution unit receives the strategy instruction packet, activates the first execution channel directly connected to the circuit breaker unit in the circuit breaker locking instruction, outputs the opening drive signal with the highest response priority and locks the reclosing function; S52: Activate the second execution channel for the harmonic elimination device activation sequence, send activation instructions to the harmonic elimination device controller in stages according to a preset coordination sequence, and retain a status monitoring window between adjacent instructions; S53, when the protection strategy generation unit outputs the instruction, the data priority scheduler immediately allocates the highest priority communication bandwidth to the first execution channel and dynamically expands the bandwidth for the second execution channel; S54. When a supplementary diagnostic request is received, the periodic monitoring data is downgraded to a compressed transmission mode, and the released bandwidth resources are allocated to the virtual verification data stream; S55. After the instruction is executed, an execution message including the information of the locking state release, the operation state of the detuning device and the communication bandwidth recovery is generated and uploaded via the intelligent communication interface.

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