A primary and secondary fusion ring network box DTU multi-interval cooperative protection and self-healing method and system

Abstract

The application provides a primary and secondary fusion ring network box DTU multi-interval collaborative protection and self-healing method and system, relates to the technical field of power distribution network relay protection and power distribution automation, and comprises the following steps: acquiring real-time operation electrical sequence of multi-interval units of the ring network box, triggering a collaborative protection process when exceeding a preset starting threshold; extracting low-frequency fluctuation components of steady-state characteristic sequences before faults of each interval unit to calculate background temperature drift compensation parameters; performing numerical subtraction reconstruction on transient electrical characteristic sequences when power grid faults occur based on the background temperature drift compensation parameters to generate calibrated transient electrical characteristic sequences; calculating the relative deviation coefficient between compensation parameters of adjacent interval units, performing dynamic proportional amplification on initial differential braking boundary values to generate safe braking boundary values; calculating collaborative differential measurement values based on the calibrated sequences, determining a protection zone fault when the measurement values exceed a limit, and issuing physical isolation and self-healing power supply instructions. The application excludes temperature drift interference and improves the accuracy of protection action determination.

Description

Technical Field

[0001] This invention relates to the field of power distribution network relay protection and power distribution automation technology, and in particular to a method and system for multi-bay collaborative protection and self-healing of primary and secondary integrated ring network box DTUs. Background Technology

[0002] Currently, integrated primary and secondary ring main units (RMUs) are widely used in the power distribution and control aspects of power distribution networks. A RMU system typically contains multiple spatially compact bay units. Each bay unit relies on distributed distribution terminal equipment to collect underlying electrical quantity information and achieves coordinated differential protection and fault self-healing power transfer through data communication between multiple bays. This multi-bay coordinated protection mechanism relies on comparing the transient electrical quantities of adjacent nodes to perform differential calculations, playing a supporting role in ensuring the safe and stable operation of the power distribution network.

[0003] In the actual physical operation of a ring main unit system, due to the differences in electrical loads connected to each branch feeder, the actual load current carried by different bay units is usually unbalanced. This unbalanced load current creates an asymmetrical thermal radiation field within the relatively enclosed internal space of the ring main unit. As the fundamental component of the underlying electrical sampling unit, the operating characteristics of electronic instrument transformers are physically related to the operating temperature of the external environment. The asymmetrical internal thermal radiation environment causes differentiated temperature drift interference to the electronic instrument transformers configured in different bay units, resulting in varying degrees of low-frequency temperature drift superimposed on the underlying electrical characteristic sequences of each bay node.

[0004] Existing multi-bay cooperative differential protection algorithms typically rely on pre-set fixed differential braking boundary values ​​to determine fault actions. When the transient electrical data collected at the lower level includes the aforementioned differentiated background temperature drift, directly performing cross-bay fusion calculations on sequences with their respective deviations will result in accumulated errors at the algebraic numerical level. Fixed safety braking boundary parameters are difficult to adapt to dynamic changes in the degree of thermodynamic asymmetry within the equipment. When faced with real-world operating conditions involving shifts in the physical thermal field of the underlying equipment, this can easily introduce uncertainty into the judgment conditions for identifying actual faults in multi-bay cooperative differential protection zones, hindering the stable execution of multi-bay physical isolation and self-healing power supply operations. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for multi-bay collaborative protection and self-healing of primary and secondary integrated ring main unit (DTU), in order to solve the technical problems of existing multi-bay collaborative protection schemes when facing the asymmetric thermal radiation field caused by load imbalance inside the ring main unit. These problems include the differential temperature drift interference generated by electronic instrument transformers, which leads to the accumulation of errors in cross-bay sequence fusion calculations, and the difficulty of the fixed differential braking boundary adapting to the underlying thermodynamic dynamic changes, thus affecting the accuracy of fault determination in the protection zone.

[0006] In a first aspect, the present invention provides a method for multi-bay collaborative protection and self-healing of primary and secondary integrated ring main unit (DTU) systems, applicable to ring main systems containing multiple bay units, the method comprising:

[0007] Obtain the real-time operating electrical sequence of multiple bay units in the ring network box system;

[0008] When the real-time operating electrical sequence is detected to exceed the preset start threshold, a multi-interval collaborative protection process is triggered;

[0009] The multi-interval collaborative protection process includes:

[0010] Extract the pre-fault steady-state feature sequence of each interval unit, and calculate the background temperature drift compensation parameter caused by the asymmetric thermal radiation field for each interval unit based on the low-frequency fluctuation component of the pre-fault steady-state feature sequence.

[0011] Extract the transient electrical feature sequence corresponding to the moment when the power grid fault occurs;

[0012] Based on the background temperature drift compensation parameters corresponding to each interval unit, the transient electrical characteristic sequence of the corresponding interval unit is reconstructed by numerical subtraction to generate a calibrated transient electrical characteristic sequence.

[0013] Calculate the relative deviation coefficient between the background temperature drift compensation parameters corresponding to each of two adjacent interval units;

[0014] Based on the relative deviation coefficient, the initial differential braking boundary value in the multi-interval collaborative protection process is dynamically proportionally amplified to generate a safe braking boundary value; wherein, the initial differential braking boundary value is a preset multiple of the effective value of the unbalanced current calculated under the maximum external short-circuit condition of the protected interval.

[0015] By integrating the calibrated transient electrical characteristic sequences corresponding to each interval unit, the coordinated differential measurement value is calculated.

[0016] When the calculated value of the coordinated differential exceeds the safety braking boundary value, it is determined that a substantial fault has occurred in the corresponding protection zone, and a physical isolation trip command is issued to the corresponding bay unit, and a self-healing power supply command is executed after isolation.

[0017] Optionally, obtaining the real-time operating electrical sequence of multiple bay units in the ring main unit system includes:

[0018] The three-phase current sequence and three-phase voltage sequence of each bay unit are synchronously acquired through electronic instrument transformers.

[0019] The three-phase current sequence and the three-phase voltage sequence are aligned according to a preset time section to obtain the real-time operating electrical sequence.

[0020] When the real-time operating electrical sequence is detected to exceed a preset start threshold, a multi-interval collaborative protection process is triggered, including:

[0021] Extract the abrupt change amplitude of the three-phase current sequence. When the abrupt change amplitude is greater than a preset current abrupt change threshold, determine that the real-time operating electrical sequence has exceeded the preset start-up threshold.

[0022] Optionally, issuing a physical isolation trip command to the corresponding bay unit includes:

[0023] Extract the polarity of the steady-state fault power direction for each interval unit;

[0024] Compare the polarity of the steady-state fault power direction between adjacent interval units;

[0025] When the steady-state fault power direction polarity of two adjacent interval units is positive, that is, when the topological convergence characteristic of energy flowing from both sides into the protected area is shown, the protected area is determined to be the actual fault interval.

[0026] Generate isolation trip pulses for the circuit breakers at the boundaries of both sides of the actual fault section;

[0027] The isolation trip pulse is sent to the operation actuator corresponding to the boundary circuit breaker as the physical isolation trip command.

[0028] Optionally, before generating the isolation trip pulse for the circuit breakers on both sides of the actual fault interval, the method further includes:

[0029] According to the general object-oriented substation event message format, the steady-state fault power direction polarity corresponding to each bay unit is encapsulated into a peer-to-peer shared message;

[0030] The peer-to-peer shared messages are sent to adjacent nodes through the communication bus inside the ring network system, completing data interaction between multiple intervals.

[0031] Optionally, executing the self-healing power supply command after isolation includes:

[0032] After the boundary circuit breaker completes the disconnection operation, the tie switch in the open state is found according to the pre-configured distribution network topology matrix;

[0033] Monitor the voltage phase difference value on both sides of the communication switch;

[0034] When the voltage phase difference value is within the allowable parallel range, a closing level signal is sent to the interconnecting switch to restore power supply to the non-faulty area.

[0035] Optionally, the step of calculating the background temperature drift compensation parameters caused by the asymmetric thermal radiation field for each interval unit based on the low-frequency fluctuation components of the pre-fault steady-state characteristic sequence includes:

[0036] The steady-state feature sequence before the fault is extracted using a preset sliding time window;

[0037] The average value of the extracted pre-fault steady-state characteristic sequence is obtained by performing an integral operation;

[0038] Subtract the pre-calibrated baseline zero point value from the mean sequence to obtain the residual deviation sequence;

[0039] The residual deviation sequence is smoothed by using a low-pass digital filter, and the steady-state convergence value of the filtered output is used as the background temperature drift compensation parameter.

[0040] Optionally, the step of performing numerical subtraction reconstruction on the transient electrical characteristic sequence of the corresponding interval unit based on the background temperature drift compensation parameters corresponding to each interval unit to generate a calibrated transient electrical characteristic sequence includes:

[0041] Extract the original sampled values ​​from the transient electrical feature sequence point by point;

[0042] Subtract the corresponding background temperature drift compensation parameter from each of the original sample values ​​to obtain the corrected sample values;

[0043] The corrected sample values ​​are reassembled according to the original time series order to obtain the calibrated transient electrical characteristic sequence.

[0044] Optionally, calculating the relative deviation coefficient between the background temperature drift compensation parameters corresponding to each of two adjacent interval units includes:

[0045] Obtain the local background temperature drift compensation parameters corresponding to the local interval unit and the neighbor background temperature drift compensation parameters corresponding to the adjacent interval unit;

[0046] Calculate the absolute difference between the local background temperature drift compensation parameter and the neighboring background temperature drift compensation parameter;

[0047] The absolute difference is divided by the arithmetic mean of the local background temperature drift compensation parameter and the neighboring background temperature drift compensation parameter to output a dimensionless value reflecting the degree of thermodynamic asymmetry, and the dimensionless value is used as the relative deviation coefficient.

[0048] Optionally, the step of dynamically scaling up the initial differential braking boundary value in the multi-interval coordinated protection process based on the relative deviation coefficient to generate a safe braking boundary value includes:

[0049] When the relative deviation coefficient is less than the preset deviation tolerance threshold, the initial differential braking boundary value is directly used as the safety braking boundary value.

[0050] When the relative deviation coefficient is greater than or equal to the preset deviation tolerance threshold, the ratio of the relative deviation coefficient to the preset deviation tolerance threshold is calculated to obtain the magnification.

[0051] Multiply the initial differential braking boundary value by the magnification factor to obtain the magnified value as the safety braking boundary value.

[0052] In a second aspect, the present invention provides a primary and secondary integrated ring network box DTU multi-bay collaborative protection and self-healing system, characterized in that it includes a storage device, a processing device, and computer execution instructions stored in the storage device and executable on the processing device, wherein the computer execution instructions, when executed by the processing device, implement the steps of the method as described in any one of the first aspects.

[0053] The present invention has achieved the following beneficial effects:

[0054] This invention calculates the background temperature drift compensation parameters by extracting the low-frequency fluctuation components of the steady-state characteristic sequence before a fault, and performs numerical subtraction reconstruction on the transient electrical characteristic sequence of each bay unit. This overcomes the differential temperature drift interference of electronic transformers caused by unbalanced load thermal radiation in the compact physical distribution of the ring main unit. At the same time, it combines the relative deviation coefficient of the background temperature drift compensation parameters of adjacent bay units to dynamically scale up the initial differential braking boundary value to generate a safe braking boundary value. This control mechanism, which combines pure algebraic reconstruction of the underlying electrical data with dynamic mapping of the braking boundary, can adapt to changes in the degree of thermodynamic asymmetry inside the ring main unit. It avoids the risk of accumulated calculation errors caused by directly using fixed differential boundaries when processing temperature drift characteristic sequences, improves the accuracy of multi-bay collaborative differential measurement values ​​in the fault assessment stage, and ensures the reliability of physical isolation and self-healing power supply command issuance.

[0055] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0056] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0057] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0058] Figure 1 This is a main flowchart of a method for multi-bay collaborative protection and self-healing of a primary and secondary integrated ring network box DTU provided in an embodiment of the present invention;

[0059] Figure 2 This is a flowchart illustrating the steps of obtaining the real-time operating electrical sequence and triggering the collaborative protection process in an embodiment of the present invention;

[0060] Figure 3 This is a flowchart illustrating the steps for calculating the background temperature drift compensation parameters in an embodiment of the present invention.

[0061] Figure 4 This is a flowchart illustrating the steps for generating safe braking boundary values ​​in an embodiment of the present invention.

[0062] Figure 5 This is a flowchart illustrating the steps of issuing a physical isolation trip command and executing a self-healing power supply command in an embodiment of the present invention.

[0063] Figure 6 This is a module structure diagram of a primary and secondary integrated ring network box DTU multi-bay collaborative protection and self-healing system provided in an embodiment of the present invention. Detailed Implementation

[0064] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0065] This application discloses a method for multi-bay collaborative protection and self-healing of a primary and secondary integrated ring main unit (RMU) in a ring main unit, applied to a RMU system containing multiple bay units. In RMU systems operating in a physically compactly distributed environment, the unbalanced load currents carried by different bay units can create an asymmetric thermal radiation field within the equipment. This asymmetric thermal radiation can cause differentiated temperature drift interference to the electronic current transformers configured in each bay unit. The method provided in this application eliminates the aforementioned differentiated interference based on pure algebraic reconstruction and dynamic boundary mapping of the underlying electrical sequence. Specifically, as shown... Figure 1 As shown, the method includes:

[0066] Step S1: Obtain the real-time operating electrical sequence of multiple bay units in the ring network box system; when the real-time operating electrical sequence exceeds the preset start threshold, trigger the multi-bay collaborative protection process.

[0067] Specifically, such as Figure 2 As shown, the three-phase current sequence and three-phase voltage sequence of each bay unit are synchronously acquired through electronic instrument transformers. The three-phase current sequence and the three-phase voltage sequence are then aligned according to a preset time segment to obtain the real-time operating electrical sequence. Further, the abrupt change amplitude of the three-phase current sequence is extracted. When the abrupt change amplitude exceeds a preset current abrupt change threshold, the real-time operating electrical sequence is determined to have exceeded the preset start threshold. Specifically, a sliding window differential algorithm is used to extract the abrupt change amplitude: using the current time segment as a reference, the effective value of the three-phase current sequence within the current power frequency cycle is extracted, and the effective value of the current of the corresponding phase within the immediately preceding power frequency cycle is extracted; the effective value of the current power frequency cycle is subtracted from the effective value of the previous power frequency cycle, and the absolute value is taken as the abrupt change amplitude. This eliminates numerical interference caused by slow load fluctuations in the distribution network and accurately captures transient current impacts caused by actual short-circuit faults. The preset current abrupt change threshold is set to 1.2 to 1.5 times the rated load current amplitude of the corresponding bay unit. The specified value range defines the maximum non-fault current fluctuation increment generated by the ring main unit under normal load switching conditions, which is used to distinguish between normal load fluctuations and actual short-circuit transient impacts at the numerical judgment level. The sequence alignment is achieved by IEEE 1588 (PTP) precise time protocol to synchronize the time of each interval unit. Each unit interpolates or matches the sequence number of the original sampling point according to the globally unified timestamp to ensure that the time deviation is better than 1μs.

[0068] Step S2: Extract the pre-fault steady-state feature sequence of each interval unit, and calculate the background temperature drift compensation parameter caused by the asymmetric thermal radiation field for each interval unit based on the low-frequency fluctuation component of the pre-fault steady-state feature sequence.

[0069] Specifically, such as Figure 3 As shown, a preset sliding time window is used to extract the pre-fault steady-state characteristic sequence. It can be understood that the preset sliding time window is set to a length of 100 to 200 milliseconds, corresponding to 5 to 10 AC power grid frequency cycles, to provide the required number of steady-state waveform data samples for subsequent integration operations. An integration operation is performed on the extracted pre-fault steady-state characteristic sequence to calculate the average value, resulting in a mean sequence. Specifically, the integration operation uses the discrete mean calculation method, that is, the amplitudes of all sampling points within the sliding time window are summed and then divided by the total number of sampling points. The mean sequence is subtracted from the pre-calibrated reference zero-point value to obtain the residual deviation sequence. This eliminates the inherent static basis bias of the instrument transformer hardware, thereby purifying and extracting the dynamic temperature drift component caused by the asymmetric thermal radiation field. Further, the pre-calibrated reference zero-point value is the static output basis constant of the electronic instrument transformer under the factory-set standard ambient temperature and no input current on the primary side. A low-pass digital filter is used to smooth the residual deviation sequence. The low-pass digital filter is a first-order IIR filter, and its difference equation is: In the formula, This is the index of the sampling steps for a discrete-time series. For the residual deviation sequence in the th The current input value of each sampling point; For the filter in the first The current output value of each sampling point; For the filter in the first The previous output value of each sampling point; The smoothing coefficient is determined based on the cutoff frequency; an analytical mapping constraint between the hardware sampling cycle period and the smoothing coefficient is established, and the calibration is derived based on the discretized equivalent model of the first-order continuous system. In the formula, For the natural constant An exponential function with base 0; Pi; The target cutoff frequency, This refers to the synchronous sampling period of the underlying analog-to-digital conversion link of the electronic instrument transformer. Because the infinite impulse response filter exhibits an asymptotic tailing effect at the mathematical level, a state convergence observer is embedded in an independent computation thread to isolate the actual physical drift. The observer calculates the absolute difference between two adjacent output results in real time according to the computational step size. The underlying interrupt immediately stops the recursive iteration of the difference equation and directly latches the current characteristic value of the clock cycle output at the end of the time window if and only if the absolute difference is detected to be consistently less than or equal to the hardware quantization noise floor tolerance band of 0.01% of the rated full scale of the transformer within a sliding time window covering 10 consecutive power frequency cycles. The latched value is used as the steady-state convergence value of the filter output, i.e., the background temperature drift compensation parameter. Specifically, the cutoff frequency range of the low-pass digital filter is set to 1 Hz to 5 Hz. Setting the cutoff frequency range to 1 Hz to 5 Hz is used to physically isolate the 50 Hz power frequency signal and high-frequency electromagnetic coupling interference, and to extract the slow low-frequency drift value caused by the asymmetry of internal thermal radiation of the equipment.

[0070] Step S3: Extract the transient electrical feature sequence corresponding to the moment of power grid fault; based on the background temperature drift compensation parameters corresponding to each interval unit, perform numerical subtraction reconstruction on the transient electrical feature sequence of the corresponding interval unit to generate a calibrated transient electrical feature sequence.

[0071] Specifically, the original sampled values ​​are extracted point by point from the transient electrical feature sequence. The corresponding background temperature drift compensation parameter is subtracted from each of the original sampled values ​​to obtain the corrected sampled values. The corrected sampled values ​​are then reassembled according to the original time series order to obtain the calibrated transient electrical feature sequence.

[0072] Step S4: Calculate the relative deviation coefficient between the background temperature drift compensation parameters corresponding to each of the two adjacent interval units; based on the relative deviation coefficient, perform dynamic proportional amplification on the initial differential braking boundary value in the multi-interval collaborative protection process to generate a safe braking boundary value.

[0073] Specifically, such as Figure 4 As shown, the local background temperature drift compensation parameters corresponding to the local interval unit and the neighbor background temperature drift compensation parameters corresponding to the adjacent interval unit are obtained. The absolute difference between the local background temperature drift compensation parameters and the neighbor background temperature drift compensation parameters is calculated. The absolute difference is divided by the arithmetic mean of the local background temperature drift compensation parameters and the neighbor background temperature drift compensation parameters to output a dimensionless value reflecting the degree of thermodynamic asymmetry, and this dimensionless value is used as the relative deviation coefficient. Further, if... This represents the local background temperature drift compensation parameter, in order to The relative deviation coefficient represents the neighbor background temperature drift compensation parameter. The calculation formula is as follows: The calculation formula uses the arithmetic mean as the denominator to eliminate numerical interference from differences in the base load amplitude of different interval units on the assessment of the relative degree of thermal drift. When dealing with extremely low load cold physical conditions caused by deep nighttime valleys or no-load outages in the distribution network, the dissipation of internal heat radiation sources leads to... and The noise level is synchronously attenuated to the base white noise level of the underlying analog-to-digital channel. Directly performing division operations can easily cause division-by-zero overflow errors in the microprocessor's arithmetic unit or abnormal amplification of the noise floor. To improve the fault tolerance of the underlying computation, a pre-interception check is performed before loading the division microinstruction: the denominator is extracted. Combine it with the built-in anti-overflow constant Perform an absolute value comparison. (Constant) The value is set to three times the equivalent current measurement value corresponding to the smallest resolvable valid character code of the transformer measurement channel. If the denominator is less than or equal to a constant... The logic engine determines that the current zone's thermal field is in a balanced cold state, skips subsequent division operations, and adjusts the relative deviation coefficient. The value is assigned to zero; otherwise, the lockout is released and a normal ratio deduction instruction is issued.

[0074] When the relative deviation coefficient is less than a preset deviation tolerance threshold, the initial differential braking boundary value is directly used as the safety braking boundary value. When the relative deviation coefficient is greater than or equal to the preset deviation tolerance threshold, a ratio operation is performed between the relative deviation coefficient and the preset deviation tolerance threshold to obtain an amplification factor; the initial differential braking boundary value is multiplied by the amplification factor to obtain an amplified value, which is used as the safety braking boundary value. It can be understood that the preset deviation tolerance threshold is set to a range of 0.10 to 0.20; the initial differential braking boundary value is set to 1.2 times the effective value of the unbalanced current measured under the maximum external short-circuit condition in the protected area. The ratio operation specifically involves dividing the relative deviation coefficient by the preset deviation tolerance threshold. Let the preset deviation tolerance threshold be... The initial differential braking boundary value is Then in At that time, the magnification The safety braking boundary value Severe asymmetric thermal field distortion in the protected area will lead to a decrease in magnification. Continuous increases in voltage can excessively raise the differential action threshold, leading to fault-related failures to operate. By applying a hard-limiting clamp constraint before the final output boundary value, and combining this with the ring main unit's extreme temperature rise type testing to deduce the transient magnetization decay distortion point of the transformer core, the upper limit threshold of the system's safety amplification factor is set. Set in the range of 1.5 to 1.8.

[0075] The above The boundary parameters of the numerical range are derived and calibrated based on the physical underlying data from the extreme temperature rise type test of the ring main unit. Under full-load thermal balance test conditions, the maximum rated amplitude drift error induced by the extreme asymmetric thermal radiation field in the electronic measurement channel of the current transformer is extracted. Maximum phase deflection angle error Let the reference amplitude error and phase angle error of the equipment under steady-state conditions at room temperature be respectively... and Based on the analytical geometric model of multi-terminal differential current synthesis, the per-unit value of the foundation unbalanced current generated under the maximum external short-circuit condition is... After superimposed thermodynamic limiting temperature drift distortion, the per-unit value of the extreme imbalance current that the system may face increases to [value missing]. During the initialization and boot phase, the microprocessor directly retrieves the aforementioned factory calibration error parameters stored in non-volatile memory and performs an algebraic ratio operation on the two per-unit values. The arithmetic unit uses the calculated ratio as the upper limit threshold for the safe amplification factor. The hard mapping benchmark.

[0076] Upon receiving product feedback, the arithmetic logic core immediately triggers over-limit detection; once the amplification factor is determined... Greater than The limiting condition is triggered, and the control register adjusts the magnification. Assigned value A constant is used to limit the safety braking boundary value derived from dynamic mapping to the range of reliable judgment of short-circuit tripping in the protection zone, so as to balance the ability to resist bias interference and the sensitivity of protection action.

[0077] Step S5: Integrate the calibrated transient electrical characteristic sequences corresponding to each bay unit to calculate the cooperative differential measurement value; when the cooperative differential measurement value exceeds the safety braking boundary value, determine that a substantial fault has occurred in the corresponding protection zone, and issue a physical isolation trip command to the corresponding bay unit and execute a self-healing power supply command after isolation.

[0078] Specifically, the calibrated transient electrical characteristic sequences corresponding to each interval unit flowing into and out of the protected area are extracted. The calibrated sequences, after numerical reconstruction, remain in a one-dimensional discrete-time axis sampling point array format in terms of data architecture. They lack the phase angle coordinate attributes necessary for complex-plane orthogonal analysis and cannot directly participate in algebraic addition across dimensions. The main control core, for each extracted interval unit waveform array, uses the sudden-break-limit section as the time reference and calls the full-wave discrete Fourier frequency domain expansion operator on the discrete data block containing the complete power frequency time window. Frequency domain projection operations can filter out the exponentially decaying DC component and high-frequency noise accompanying the short-circuit transient process, analytically extracting the fundamental real and imaginary components corresponding to each node, and then reconstructing them into transient complex phasors with spatial polarity characteristics. After completing the forward time-frequency dimension conversion, phasor algebraic addition operations are performed on the extracted current sequences based on Kirchhoff's current law to calculate the comprehensive imbalance, which serves as the cooperative differential measurement value.

[0079] The synthesized imbalance output after phasor algebraic addition based on Kirchhoff's laws is presented in the microprocessor's arithmetic stack as a two-dimensional orthogonal complex number composed of the fundamental real and imaginary floating-point numbers. Considering that the safety braking boundary value generated by dynamic mapping is a one-dimensional non-negative real scalar, the multidimensional spatial differences in the data structure directly trigger the blocking of over-limit comparison instructions in the arithmetic logic unit. The arithmetic logic core forcibly intercepts this synthesized imbalanced complex phasor, pushes its internally encapsulated real and imaginary values ​​into the hardware multiply-accumulate pipeline, performs parallel square accumulation operations, and then calls the square root microinstruction to calculate the non-negative scalar absolute amplitude stripped of spatial rotation phase angle attributes. The main control program uses the calculated scalar absolute amplitude to overwrite the original complex plane phasor structure, establishing it as the final substantive cooperative differential measurement value participating in the over-limit Boolean judgment, thus establishing the hardware transmission link for fault detection actions at the underlying data type level.

[0080] Furthermore, such as Figure 5 As shown, issuing a physical isolation trip command to the corresponding bay unit includes: extracting the steady-state fault power direction polarity of each bay unit. Before calculating the phase difference, the aligned discrete voltage and current sequences of the fault phase are first extracted; then, the full-wave discrete Fourier transform (DFT) algorithm is used to perform time-frequency conversion operations on the above discrete sequences to calculate the real and imaginary parts of the fundamental voltage and fundamental current, respectively, thereby constructing the fault phase voltage phasor. With current phasor Based on this, the voltage phasors of the fault phase are calculated. With current phasor phase difference ,when In When the fault occurs within a range, the power direction polarity is determined to be positive (pointing towards the interior of the protected area), otherwise negative. Following the general substation event message format, the steady-state fault power direction polarity corresponding to each bay unit is encapsulated into a peer-to-peer shared message. This peer-to-peer shared message is sent to adjacent nodes via the communication bus within the ring network system. The steady-state fault power direction polarity of adjacent bay units is compared. When the steady-state fault power direction polarity of two adjacent bay units is both positive, indicating a topological convergence characteristic where energy from both sides flows towards the interior of the protected area, the protected area is determined to be the actual fault range. Isolation trip pulses are generated for the boundary circuit breakers on both sides of the actual fault range. These isolation trip pulses are sent to the corresponding operating actuators of the boundary circuit breakers as the physical isolation trip command.

[0081] Executing the self-healing power supply command after isolation includes: after the boundary circuit breaker completes its disconnection operation, searching for the interconnecting switches in the open state according to a pre-configured distribution network topology matrix. Specifically, the distribution network topology matrix is ​​pre-stored in the non-volatile memory of the ring network box system. This matrix maps the switch states of each connected node to a two-dimensional numerical matrix, where an element value of 0 indicates the switch is in the open state, and an element value of 1 indicates the switch is in the closed state. Further, the two-dimensional numerical matrix is ​​specifically a node adjacency matrix, where the row and column indices correspond to the physical node numbers in the distribution network topology. Matrix elements Representative node With nodes Direct electrical connection branch status between nodes: If there is a tie switch between the two nodes and the switch is in the closed state, then the matrix elements... If there is a connecting switch between the two nodes but it is in the open state, or if there is no direct physical connection between the two nodes, then the matrix elements... The system also includes a branch attribute matrix with the same dimension as the distribution network topology matrix. When node With nodes Branch roads between When a physical interconnection switch is configured, let the matrix elements... Otherwise matrix elements The system compares matrix elements. And matrix elements The system uses the intersection condition of the matrix to locate the tie switch to be operated. By traversing the off-diagonal elements of the matrix, the system extracts the coordinates of nodes with a value of 0 and pre-marked tie switch attributes, thus locating the tie switch in the open state. The system monitors the voltage phase difference across the tie switch. When the voltage phase difference is within the allowable parallel range, a closing level signal is sent to the tie switch to restore power to the non-faulty area. It is understood that the condition for determining the allowable parallel range is that the absolute value of the voltage phase difference is less than or equal to 15 degrees. These boundary conditions satisfy the physical safety wiring requirements for synchronous parallel operation of AC system voltages, avoiding inrush current impacts caused by asynchronous closing.

[0082] Before issuing the phase comparison scheduling command, the microprocessor first drives the analog sampling channels on both sides to perform live physical state identification on the instantaneous voltage level of the break. If the feedback from the underlying comparator indicates that the voltage of one side of the feeder remains above 80% of the system's rated parameters, while the level on the other side collapses to below 20% of the rated amplitude and continues to exceed the preset confirmation time window, the main control stack determines that the current network meets the single-end power failure to supply condition, directly bypasses all subsequent angle measurement and analysis modules, and releases the no-voltage closing level to the tie switch. Only when the hardware probe confirms that the amplitude of both sides of the feeder exceeds the rigid live threshold of 80%, the arithmetic unit activates the synchronization detection interrupt, calls the inverse trigonometric function to extract the phase angle of the fundamental voltage on both sides respectively, and performs the subtraction to obtain the absolute value. To avoid numerical abrupt changes caused by crossing the boundary between the first and fourth quadrants of the coordinate system, when the absolute difference calculated by subtraction crosses the 180-degree physical limit, the logic engine automatically subtracts the absolute difference using the 360-degree constant, forcing the voltage phase difference value to converge to the minimum angle representation domain, thus ensuring the uniqueness and stability of the concurrent parallel judgment mathematical measurement system in physical execution.

[0083] like Figure 6 As shown in the illustration, this application also discloses a primary and secondary integrated ring main unit (DTU) multi-bay collaborative protection and self-healing system, including a storage device, a processing device, and computer-executable instructions stored in the storage device and executable on the processing device. When executed by the processing device, the computer-executable instructions implement the steps of the aforementioned method. Specifically, the processing device employs a microprocessor with an integrated arithmetic logic unit, calling underlying hardware resources to perform sequence alignment, integral calculation, filtering, and algebraic numerical operations. The storage device includes non-volatile memory and random access memory, used to store the distribution network topology matrix, the preset current mutation threshold, the initial differential braking boundary value, and the preset deviation tolerance threshold, and to cache the collected real-time operating electrical sequence data. The processing device outputs a corresponding transient drive level signal to an external circuit breaker mechanism through a hardware control interface circuit.

[0084] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for multi-bay collaborative protection and self-healing of a primary and secondary integrated ring main unit (DTU) in a ring main unit, applied to a ring main unit system containing multiple bay units, characterized in that the method... include: Obtain the real-time operating electrical sequence of multiple bay units in the ring network box system; When the real-time operating electrical sequence is detected to exceed the preset start threshold, a multi-interval collaborative protection process is triggered; The multi-interval collaborative protection process includes: Extract the pre-fault steady-state feature sequence of each interval unit, and calculate the background temperature drift compensation parameter caused by the asymmetric thermal radiation field for each interval unit based on the low-frequency fluctuation component of the pre-fault steady-state feature sequence. The calculation of the background temperature drift compensation parameters caused by the asymmetric thermal radiation field for each interval unit based on the low-frequency fluctuation components of the pre-fault steady-state characteristic sequence includes: The steady-state feature sequence before the fault is extracted using a preset sliding time window; The average value of the extracted pre-fault steady-state characteristic sequence is obtained by performing an integral operation; Subtract the pre-calibrated baseline zero point value from the mean sequence to obtain the residual deviation sequence; The residual deviation sequence is smoothed by using a low-pass digital filter, and the steady-state convergence value of the filtered output is used as the background temperature drift compensation parameter. Extract the transient electrical feature sequence corresponding to the moment when the power grid fault occurs; Based on the background temperature drift compensation parameters corresponding to each interval unit, the transient electrical characteristic sequence of the corresponding interval unit is reconstructed by numerical subtraction to generate a calibrated transient electrical characteristic sequence. The step of performing numerical subtraction reconstruction on the transient electrical characteristic sequence of the corresponding interval unit based on the background temperature drift compensation parameters of each interval unit to generate a calibrated transient electrical characteristic sequence includes: Extract the original sampled values ​​from the transient electrical feature sequence point by point; Subtract the corresponding background temperature drift compensation parameter from each of the original sample values ​​to obtain the corrected sample values; The corrected sample values ​​are reassembled according to the original time series order to obtain the calibrated transient electrical characteristic sequence. Calculate the relative deviation coefficient between the background temperature drift compensation parameters corresponding to each of two adjacent interval units; The calculation of the relative deviation coefficient between the background temperature drift compensation parameters corresponding to two adjacent interval units includes: Obtain the local background temperature drift compensation parameters corresponding to the local interval unit and the neighbor background temperature drift compensation parameters corresponding to the adjacent interval unit; Calculate the absolute difference between the local background temperature drift compensation parameter and the neighboring background temperature drift compensation parameter; Divide the absolute difference by the arithmetic mean of the local background temperature drift compensation parameter and the neighboring background temperature drift compensation parameter to output a dimensionless value that reflects the degree of thermodynamic asymmetry, and use the dimensionless value as the relative deviation coefficient. Based on the relative deviation coefficient, the initial differential braking boundary value in the multi-interval collaborative protection process is dynamically proportionally amplified to generate a safe braking boundary value; wherein, the initial differential braking boundary value is a preset multiple of the effective value of the unbalanced current calculated under the maximum external short-circuit condition of the protected interval. The step of dynamically scaling up the initial differential braking boundary value in the multi-interval coordinated protection process based on the relative deviation coefficient to generate a safe braking boundary value includes: When the relative deviation coefficient is less than the preset deviation tolerance threshold, the initial differential braking boundary value is directly used as the safety braking boundary value. When the relative deviation coefficient is greater than or equal to the preset deviation tolerance threshold, the ratio of the relative deviation coefficient to the preset deviation tolerance threshold is calculated to obtain the magnification. Multiply the initial differential braking boundary value by the magnification factor to obtain the magnified value as the safety braking boundary value; By integrating the calibrated transient electrical characteristic sequences corresponding to each interval unit, the coordinated differential measurement value is calculated. When the calculated value of the coordinated differential exceeds the safety braking boundary value, it is determined that an actual fault has occurred in the corresponding protected section, and a physical isolation trip command is issued to the corresponding bay unit, and a self-healing power supply command is executed after isolation.

2. The method according to claim 1, characterized in that, The acquisition of the real-time operating electrical sequence of multiple bay units in the ring main unit system includes: The three-phase current sequence and three-phase voltage sequence of each bay unit are synchronously acquired through electronic instrument transformers. The three-phase current sequence and the three-phase voltage sequence are aligned according to a preset time section to obtain the real-time operating electrical sequence. When the real-time operating electrical sequence is detected to exceed a preset start threshold, a multi-interval collaborative protection process is triggered, including: Extract the abrupt change amplitude of the three-phase current sequence. When the abrupt change amplitude is greater than a preset current abrupt change threshold, determine that the real-time operating electrical sequence has exceeded the preset start-up threshold.

3. The method according to claim 2, characterized in that, The step of issuing a physical isolation trip command to the corresponding bay unit includes: Extract the polarity of the steady-state fault power direction for each interval unit; Compare the polarity of the steady-state fault power direction between adjacent interval units; When the steady-state fault power direction polarity of two adjacent interval units is positive, that is, when the topological convergence characteristic of energy flowing from both sides into the protected interval is shown, the protected interval is determined to be the actual fault interval. Generate isolation trip pulses for the circuit breakers at the boundaries of both sides of the actual fault section; The isolation trip pulse is sent to the operation actuator corresponding to the boundary circuit breaker as the physical isolation trip command.

4. The method according to claim 3, characterized in that, Before generating the isolation trip pulse for the circuit breakers on both sides of the actual fault interval, the method further includes: According to the general object-oriented substation event message format, the steady-state fault power direction polarity corresponding to each bay unit is encapsulated into a peer-to-peer shared message; The peer-to-peer shared messages are sent to adjacent bay units through the communication bus inside the ring network system, completing the data interaction between multiple bays.

5. The method according to claim 4, characterized in that, The execution of the self-healing power supply command after isolation includes: After the boundary circuit breaker completes the disconnection operation, the tie switch in the open state is found according to the pre-configured distribution network topology matrix; Monitor the voltage phase difference value on both sides of the communication switch; When the voltage phase difference value is within the allowable parallel range, a closing level signal is sent to the interconnecting switch to restore power supply to the non-faulty area.

6. A multi-bay collaborative protection and self-healing system for a primary and secondary integrated ring main unit (DTU), characterized in that, It includes a storage device, a processing device, and computer-executable instructions stored in the storage device and executable on the processing device, wherein the computer-executable instructions, when executed by the processing device, implement the steps of the method as described in any one of claims 1 to 5.

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