A multi-epitope electric fast transient group immunity experiment method and system

Abstract

The application discloses a multi-epitope electrical fast transient burst immunity test method and system, and belongs to the technical field of electromagnetic compatibility testing, which comprises the following steps: constructing an epitope electrical topology graph; applying a broadband scanning excitation and collecting voltage and current response vectors, generating a multi-port impedance coupling matrix through distributed parameter decoupling calculation; performing eigenvalue decomposition to extract intrinsic resonance frequencies and modal vectors; extracting optimal resonance frequencies based on the minimum modal damping ratio; tuning the pulse repetition frequency to the optimal resonance frequency, generating matching instructions based on the impedance coupling matrix, and synchronously applying electrical fast transient bursts; sending communication instructions during the pulse pause period, and constructing an immunity critical parameter set based on the absence of communication response. The application adopts an active resonance mode excitation and differential energy injection method, combines micro-signal listening and pre-failure judgment, and adopts a closed-loop test strategy, so that accurate and efficient evaluation of the immunity boundary can be realized, and quantitative guidance for product optimization is provided.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic compatibility testing technology, and in particular to a multi-position electrical fast transient / burst immunity test method and system. Background Technology

[0002] In the construction and operation of smart grids, smart meters serve as crucial metering and sensing terminals, and their reliability directly impacts the data acquisition quality and operational safety of the power grid. To verify the stability of smart meters under transient high-frequency interference generated by complex operating conditions such as grid switching, lightning strikes, or grounding faults, electrical fast transient / burst immunity testing is an essential type test item.

[0003] In related technologies, Chinese invention patent application with publication number CN117741548A discloses a fast burst immunity test system and method for smart energy meters, including a communication protocol library module for calling the protocol to form data comparison, an error test point configuration library module for configuring error sampling parameters and error sampling test points, and also includes a data attack module connected to the energy meter under test, a device control module, and a communication control module.

[0004] The aforementioned technologies primarily focus on verifying the logic function and assessing data integrity of electricity meters under interference conditions. However, in actual production and testing, it is often necessary to perform batch parallel testing on multiple electricity meters at multiple locations. When facing multi-location testing scenarios, these technologies neglect the changes in load characteristics of the test circuit caused by the simultaneous connection of multiple devices under test. They cannot guarantee that the test signal remains consistent across meter locations, leading to deviations in the actual interference intensity experienced by each meter, and resulting in low accuracy and reproducibility of batch test results. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a multi-position electrical fast transient / burst immunity test method and system. It employs a closed-loop testing strategy that combines active excitation of resonant modes with differentiated energy injection, microscopic signal listening, and pre-failure determination. This approach enables accurate and efficient assessment of immunity boundaries and provides quantitative guidance for product optimization.

[0006] The above objectives can be achieved through the following approach: A method for testing the immunity to electrical fast transient / burst disturbances at multiple ports includes: recording the port numbers and mechanical installation coordinates of the ports using a multi-port test bench to construct an electrical topology diagram of the ports; applying a broadband sinusoidal scanning excitation voltage to the multi-port test bench, simultaneously acquiring frequency domain voltage response vectors and current response vectors using the ports, mapping the frequency domain voltage response vectors and current response vectors to the electrical topology diagram of the ports for distributed parameter decoupling calculation, and generating a multi-port impedance coupling matrix; performing complex domain eigenvalue decomposition on the multi-port impedance coupling matrix, and extracting an intrinsic resonant frequency table and an intrinsic mode vector set using eigenvalues; and based on the intrinsic mode... The modal damping ratio is calculated using the state vector group. The optimal resonant frequency is extracted from the intrinsic resonant frequency table when the modal damping ratio reaches its minimum value. The pulse repetition frequency is tuned to the optimal resonant frequency using an electric fast transient pulse generator. An impedance matching control command is generated based on the multi-port impedance coupling matrix, and an electric fast transient pulse group is synchronously applied to all meter positions. During the interval between two adjacent electric fast transient pulse groups, a communication read command is sent to all meter positions to collect meter readings and communication response flags. When the first communication response flag is missing, the pulse group number, pulse repetition frequency, and peak voltage are extracted to construct a critical parameter set for immunity.

[0007] Optionally, the construction of the meter position electrical topology diagram includes: injecting identification pulse signals sequentially into the meter position ports through the multi-meter position test bench, recording the meter position port number and mechanical installation position coordinates according to the response order, and generating a meter position number coordinate lookup table; extracting the adjacent coordinate spacing and port connection line sequence based on the meter position number coordinate lookup table, and constructing the meter position electrical topology diagram with the meter position number as the node and the connection line sequence as the edge.

[0008] Optionally, generating the multi-port impedance coupling matrix includes: controlling the multi-position test bench to output a broadband sinusoidal scanning excitation voltage; performing a fast Fourier transform on the time-domain sampled data to extract the fundamental amplitude and phase to generate a frequency-domain voltage response vector and a current response vector; analyzing the node connection distance and cable characteristic impedance based on the electrical topology diagram of the position, and constructing a transmission line transmission parameter matrix for the cable distributed inductance and distributed capacitance; using the transmission line transmission parameter matrix to perform an inverse transmission matrix de-embedding operation on the frequency-domain voltage response vector and the current response vector, removing the cable transmission effect, and extracting the port equivalent impedance to generate the multi-port impedance coupling matrix.

[0009] Optionally, generating the multi-port impedance coupling matrix includes: performing matrix inversion on the transmission line transmission parameter matrix to generate a de-embedding inverse matrix, and performing a matrix left multiplication on the de-embedding inverse matrix with the frequency domain voltage response vector and the current response vector to generate a true voltage vector and a true current vector at the port; performing complex division on the true voltage vector and the true current vector at the port to calculate the equivalent complex impedance of the port at each frequency point, and filling the multi-port impedance coupling matrix according to the port number index order.

[0010] Optionally, the step of extracting the intrinsic resonant frequency table and intrinsic mode vector set using eigenvalues ​​includes: performing a similar diagonalization transformation operation on the multi-port impedance coupling matrix at each frequency sweep point to decouple and generate a diagonalized modal impedance matrix and a transformation feature matrix; searching for local minima of the amplitude of the diagonal elements in the diagonalized modal impedance matrix to extract the frequency points and generate an intrinsic resonant frequency table, and extracting column vectors from the transformation feature matrix to construct an intrinsic mode vector set.

[0011] Optionally, the extraction of the optimal resonant frequency includes: performing a modal space projection operation on the multi-port impedance coupling matrix using the intrinsic mode vector set to generate a modal impedance frequency response curve, and calculating the half-power bandwidth value of the modal impedance frequency response curve; performing a ratio operation between the half-power bandwidth value and the intrinsic resonant frequency table to generate a modal damping ratio sequence, and locking the minimum value index in the modal damping ratio sequence to extract the optimal resonant frequency.

[0012] Optionally, the synchronous application of electrical fast transient pulses to all meter positions includes: writing the optimal resonant frequency to the digital timing controller of the electrical fast transient pulse generator, performing clock division calculation to reconstruct the single-pulse repetition period parameters; extracting the imaginary part of the diagonal elements of the multi-port impedance coupling matrix at the optimal resonant frequency, calculating the compensation reactance parameters required to offset the imaginary part, generating capacitor array switching instructions and inductor array adjustment instructions as impedance matching control instructions; driving the relay switch matrix in the impedance compensation distribution network to load the impedance matching control instructions, and triggering the high-voltage solid-state switch according to the single-pulse repetition period parameters to synchronously output electrical fast transient pulses to all meter positions.

[0013] Optionally, the generation of capacitor array switching instructions and inductor array adjustment instructions includes: determining the sign polarity based on the imaginary part value; performing a reciprocal transformation calculation from inductive reactance to capacitive compensation value using the optimal resonant frequency when the polarity is positive; and performing a proportional transformation calculation from capacitive reactance to inductive compensation value when the polarity is negative, to generate target compensation element values; performing binary encoding mapping between the target compensation element values ​​and the impedance compensation distribution network hardware to generate high and low level bit sequences of the switching channel, and combining them to construct capacitor array switching instructions and inductor array adjustment instructions.

[0014] Optionally, the construction of the immunity critical parameter set includes: monitoring the interval between two adjacent electrical fast transient pulse groups, recording the start time of the interval, and broadcasting a communication read command to all port positions; opening an independent receive waiting window for each port position, setting the communication response flag to zero if no response frame is received before the window closes, otherwise setting it to one; traversing the communication response flag, locking the port position index where the flag bit changes from one to zero, reading the pulse group sequence number, pulse repetition frequency, and peak voltage from the generator register at the current time, and constructing the immunity critical parameter set.

[0015] Based on the same inventive concept, this invention also provides a multi-port electrical fast transient / burst immunity test system. The system includes: a port topology construction module, used to record port numbers and mechanical installation coordinates on a multi-port test bench to construct an electrical topology diagram of the ports; an impedance coupling matrix generation module, used to apply a broadband sinusoidal scanning excitation voltage to the multi-port test bench, simultaneously acquire frequency domain voltage response vectors and current response vectors using the port numbers, map the frequency domain voltage response vectors and current response vectors to the electrical topology diagram of the ports for distributed parameter decoupling calculation, and generate a multi-port impedance coupling matrix; and an intrinsic mode extraction module, used to perform complex domain eigenvalue decomposition on the multi-port impedance coupling matrix, and extract intrinsic resonant frequency tables and intrinsic mode vectors using eigenvalues. The system comprises: an optimal resonant frequency extraction module, used to calculate the modal damping ratio based on the intrinsic mode vector group, and extract the optimal resonant frequency from the intrinsic resonant frequency table when the modal damping ratio reaches its minimum value; a pulse group synchronous application module, used to tune the pulse repetition frequency to the optimal resonant frequency through an electric fast transient pulse generator, and generate an impedance matching control command based on the multi-port impedance coupling matrix to synchronously apply electric fast transient pulse groups to all meter positions; and an immunity critical parameter construction module, used to send communication read commands to all meter positions during the interval between two adjacent electric fast transient pulse groups, collect meter readings and communication response flags, and extract the pulse group sequence number, pulse repetition frequency, and peak voltage when the first communication response flag is missing, to construct an immunity critical parameter set.

[0016] Compared with the prior art, the present invention has the following advantages: 1. By constructing a dynamic electrical topology map and actively exciting the system's resonant modes, the test stress can be precisely focused on the most vulnerable resonant points in the physical structure and electrical characteristics of the multi-position system. Compared with traditional broadband or fixed-frequency scanning methods, this improves the targeting of the test and the efficiency of discovering potential design defects. 2. By adopting a differentiated energy injection strategy that matches the system's resonance mode, and combining real-time listening to micro-noise signals with pre-failure state determination, accurate and non-destructive detection of the anti-disturbance boundary is achieved, avoiding permanent damage to the equipment due to overstress testing, and obtaining more refined performance margin data than traditional macro-failure determination. 3. By learning from and modeling the results of multiple tests, a multidimensional immunity boundary map is finally constructed, which transforms discrete test data into an intuitive and comprehensive profile of equipment performance. This not only determines whether the equipment is qualified, but also reveals the inherent laws of its immunity performance changes with factors such as frequency and energy injection mode, providing quantitative and traceable data support for product design optimization and reliability hardening.

[0017] Other features and advantages of the invention will be set forth in the description which follows, 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 pointed out in the description, claims and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating a multi-tablet electrical fast transient / burst immunity test method according to an embodiment of the present invention.

[0020] Figure 2 This is a heat map showing the amplitude distribution of the multi-port impedance coupling matrix according to an embodiment of the present invention.

[0021] Figure 3 This is a distribution diagram showing the correlation between the intrinsic resonant frequency and the modal damping ratio in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of a multi-position electrical fast transient / burst immunity experimental system according to an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Reference Figure 1 One embodiment of the present invention proposes a multi-position electrical fast transient burst immunity test method. It adopts a closed-loop test strategy that combines active excitation of resonant modes and differential energy injection with microscopic signal listening and pre-failure judgment. This method can achieve accurate and efficient evaluation of immunity boundaries and provide quantitative guidance for product optimization.

[0025] The method described in this embodiment specifically includes: By recording the port number and mechanical installation coordinates of the multi-position test bench, an electrical topology diagram of the position is constructed. A broadband sinusoidal scanning excitation voltage is applied to the multi-position test bench, and the frequency domain voltage response vector and current response vector are acquired simultaneously using the position ports. The frequency domain voltage response vector and current response vector are mapped to the position electrical topology diagram for distributed parameter decoupling calculation, and a multi-port impedance coupling matrix is ​​generated. Perform complex domain eigenvalue decomposition on the multi-port impedance coupling matrix, and extract the intrinsic resonant frequency table and intrinsic mode vector group using the eigenvalues; The modal damping ratio is calculated based on the intrinsic mode vector set, and the optimal resonance frequency is extracted from the intrinsic resonant frequency table when the modal damping ratio reaches its minimum value. The pulse repetition frequency is tuned to the optimal resonant frequency by an electric fast transient pulse generator, and an impedance matching control command is generated according to the multi-port impedance coupling matrix to synchronously apply an electric fast transient pulse group to all positions. During the interval between two consecutive electrical fast transient pulse groups, a communication read command is sent to all meter positions to collect meter readings and communication response flags. When the first communication response flag is missing, the pulse group number, pulse repetition frequency and peak voltage are extracted to construct a set of critical parameters for immunity.

[0026] Optionally, the construction of the tabletop electrical topology diagram includes: The multi-position test bench sequentially injects identification pulse signals into the position ports, records the position port number and mechanical installation position coordinates according to the response order, and generates a position number coordinate lookup table. The control center of the multi-meter station test bench drives its internal signal generation unit to inject an identification pulse signal into the busbars of the series- or parallel-connected meter station ports. This identification pulse signal is configured as a low-voltage signal that will not trigger the metering function of the energy meter but can be captured by the communication interface, such as a TTL level signal with an amplitude of 5V to 12V, and a rise time of less than 10 nanoseconds to ensure the accuracy of the timestamp recording. Each meter station port on the test bench is equipped with a signal capture unit. When the rising edge of the identification pulse signal is captured, this unit immediately sends a trigger signal back to the control center. The control center determines the physical flow order of the signal on the transmission line based on the order in which the feedback signals are received, i.e., the response order. Simultaneously, the control center retrieves the mechanical installation position coordinates pre-stored in the test bench configuration database, binds these coordinates to the meter station port number that captured the signal, and generates a meter station number coordinate lookup table.

[0027] For example, suppose a test bench with 6 positions is configured so that the control center sends a 5V identification pulse with a width of 50ns. Due to cable transmission delay, port 1, which is closest to the signal source, will first receive the pulse. The system responds in real time, records its number as ID_01, and retrieves its coordinates from the database. ; then port 2 in Respond at any time and record its ID_02 and its coordinates. The final generated table of position number coordinates is structured data, such as: [{ID:01,Pos:(0.2,0,0)},{ID:02,Pos:(0.5,0,0)},…], with the position unit being meters.

[0028] Based on the coordinate lookup table of the table position number, the distance between adjacent coordinates and the connection sequence of the port are extracted, and the table position electrical topology diagram is constructed with the table position number as the node and the connection sequence as the edge.

[0029] Using a lookup table, the port connection sequence is determined by analyzing the response order, i.e., the flow path of current or interference signals in the actual test. For two adjacent ports in the connection sequence, their mechanical installation coordinates are extracted, and the equivalent electrical clearance between them is calculated using the spatial Euclidean distance formula combined with the cable bending coefficient. The calculation formula is as follows: , in, Indicates the first line in the connection sequence The first table port and the first The equivalent physical length of the cable between each port, measured in meters, directly determines the magnitude of the distributed inductance and distributed capacitance. The cable bending coefficient is a dimensionless correction factor determined based on the actual cabling process of the test bench cable trays. For example, if the cable is laid in a straight line, then... Take 1.0; if the cable has right-angle bends or redundant coils within the slot, then The value is usually between 1.1 and 1.2. and These represent the coordinates of the table position numbers in the coordinate lookup table. The and the first The three-dimensional spatial coordinates of each tabletop port are given, in meters. Finally, using graph theory algorithms, each tabletop number is instantiated as a node in the graph, the connection relationships between adjacent ports are instantiated as directed edges, and the calculated... The weights of the corresponding edges are assigned to construct the tabletop electrical topology diagram containing physical dimension information.

[0030] For example, in a 6-position test bench scenario, ID_01 and ID_02 were identified as adjacent and connected. The coordinates of ID_01 are known to be... The coordinates of ID_02 are Furthermore, the test bench wiring is laid in a straight line, meaning the bending coefficient is low. Substitute into the formula to calculate: Then, a directed edge from node ID_01 to node ID_02 is created in the electrical topology graph, and the weight attribute of this edge is set to 0.3m. This 0.3m length data will be used to look up the transmission line parameter library to determine how much distributed inductance and distributed capacitance this section of cable introduces.

[0031] Optionally, generating the multi-port impedance coupling matrix includes: The multi-position test bench is controlled to output a broadband sinusoidal scanning excitation voltage, and a fast Fourier transform is performed on the time-domain sampled data to extract the fundamental amplitude and phase to generate frequency-domain voltage response vector and current response vector. First, the central processing unit sends a scanning command to the arbitrary waveform generator, controlling it to output a broadband sinusoidal scanning excitation voltage to the signal injection bus of the test bench. To cover the main energy frequency bands of the Electrical Fast Transient (EFT) from the fundamental wave to higher harmonics, the frequency range of this excitation voltage is set from 10 kHz to 100 MHz, with the step frequency set according to the test accuracy requirements. At each discrete scanning frequency point, the voltage and current waveforms of all meter ports are simultaneously acquired at a sampling rate satisfying the Nyquist sampling theorem, for example, 500 MSps, forming discrete time-domain sampled data. Subsequently, a Fast Fourier Transform (FFT) is performed on each set of time-domain sampled data. In the frequency domain spectrum, a frequency point equal to the current scanning frequency is locked, and the complex data corresponding to that frequency point, i.e., the fundamental amplitude and phase information, is extracted. The complex voltage values ​​of all meter ports at the same time and frequency are arranged in an ordered manner to construct a frequency-domain voltage response vector; similarly, a current response vector is constructed.

[0032] Based on the electrical topology diagram of the table, the node connection distance and cable characteristic impedance are analyzed, and a transmission line transmission parameter matrix is ​​constructed for the distributed inductance and distributed capacitance of the cable. Call the table-top electrical topology diagram and extract the signal source to any number of nodes. The physical path length between each table port is denoted as the node connection distance. Simultaneously, the characteristic impedance of the internal connecting cables of the test bench is read from the cable specification database. For example, coaxial cables are typically 50 ohms or 75 ohms, and the phase velocity... Based on transmission line theory, cables at high frequencies are no longer simple conductors, but rather distributed parameter circuits composed of distributed inductance and capacitance. To mathematically describe this distributed effect, a transmission line transmission parameter matrix for a two-port network is constructed for each segment of the connecting cable. This matrix is ​​constructed based on the following formula: , in, The transmission line transmission parameter matrix is ​​a... A complex matrix is ​​used to describe the transformation relationship of voltage and current signals after transmission through cables. This represents the node connection distance obtained from the electrical topology diagram of the table, in meters, and represents the physical distance for signal transmission. This represents the characteristic impedance of the cable, measured in ohms. This value is derived from the technical specifications provided by the cable manufacturer or from measurements obtained through pre-calibration using the open / short circuit method. and Let represent the hyperbolic sine function and the hyperbolic cosine function, respectively. The propagation constant is a complex number, and its calculation formula is: . It is the attenuation constant, which describes the loss of signal amplitude, and is the test data of the loss tangent of the cable material. It is the imaginary unit. It is a phase constant that describes the lag in the signal phase, and its calculation formula is: ,in The current scanning frequency, This refers to the speed at which a signal travels through a cable, typically 66% to 85% of the speed of light.

[0033] For example, assuming the current scanning frequency The frequency is 10MHz. The cable length leading to position 1 is obtained by analysis. The cable is 2 meters long and has a characteristic impedance of [missing information]. With a strength of 50 ohms, the propagation speed Pick m / s, ignoring cable loss. First, calculate the phase constant. : , and then calculate : Substitute into the matrix formula to calculate the elements. : Calculate elements : Finally, a transmission line transmission parameter matrix for that frequency point and that section of cable is constructed. This matrix quantifies the distributed parameter effects introduced by a 2-meter cable at 10MHz.

[0034] The inverse transmission matrix de-embedding operation is performed on the frequency domain voltage response vector and the current response vector using the transmission line transmission parameter matrix. After eliminating the cable transmission effect, the port equivalent impedance is extracted to generate a multi-port impedance coupling matrix.

[0035] A calibration algorithm based on matrix inverse operation is executed to restore the true electrical state of the meter position port. During measurement, the voltage vector is acquired. and current vector In fact, it is transmitted through a cable matrix. The transformed result. This is to obtain the true voltage vector of the position port unaffected by the cable. With the real current vector Perform the following inverse transfer matrix de-embedding operation: , in, This is the inverse matrix of the transmission line transmission parameter matrix. Through this operation, the phase delay and amplitude attenuation introduced by the physical cable are mathematically removed. After obtaining the true vector, the 1st... The equivalent impedance of each port at the current frequency. Finally, by traversing every frequency point within the scanning frequency range, the calculated equivalent impedance values ​​of all positions are filled in according to the position number and frequency index to generate a multi-dimensional multi-port impedance coupling matrix. This matrix not only contains the self-impedance of each port but also includes the mutual impedance information between ports through multi-port network analysis.

[0036] For example, suppose the voltage measured by the data acquisition card at the signal source end... Current First, calculate the matrix. inverse matrix For a reciprocal lossless network, the inverse matrix is: Then perform the left multiplication operation: , After complex number operations, the actual voltage at the meter position port is calculated. and real current Assuming the final calculated , Then the equivalent impedance of the port at this frequency is: , will this The complex values ​​are filled into the corresponding positions in the multi-port impedance coupling matrix. In this way, even if the test bench cable is very long, it is possible to "see through" the cable and obtain the most accurate impedance data of the test position.

[0037] Optionally, generating the multi-port impedance coupling matrix includes: Perform matrix inversion on the transmission line transmission parameter matrix to generate a de-embedding inverse matrix, and perform left matrix multiplication on the de-embedding inverse matrix with the frequency domain voltage response vector and the current response vector to generate the actual voltage vector and the actual current vector of the position port. In mathematics, the measurement port and the position port of the test bench are connected by a transmission line, which has been modeled as a transmission line transmission parameter matrix. To reconstruct the true signal at the port, reverse derivation must be performed. First, the linear algebra library is called to calculate the signal at each frequency point. Dimensional transmission line transmission parameter matrix Perform matrix inversion to generate the de-embedding inverse matrix. For reciprocal lossless or low-loss transmission lines, its determinant value is... The physical meaning of the inverse matrix is ​​to "backtrack" the signal along the transmission line to its source. Subsequently, a combined column vector containing the original measurement data is constructed, which is the frequency domain voltage response vector. As the first element, the current response vector As the second element, the inverse matrix will be embedded. Multiply the combined column vector by left to calculate the actual voltage vector at the position port. With the real current vector The calculation formula is as follows: , in, and These represent the true voltage vector and true current vector at the meter port after de-embedding calibration, respectively, in volts and amperes, representing the values ​​that can be measured if the measuring probe is directly in contact with the electricity meter terminals. and These represent the original frequency domain voltage response vector and current response vector acquired at the instrument port of the test bench, respectively. It is the transmission line transmission parameter matrix The four complex elements in the equation. and It is a dimensionless voltage / current transfer ratio; It is a transfer impedance with impedance dimensions; It is the transfer admittance with admittance dimensions. The negative sign "-" represents phase reversal in the inverse operation, which physically corresponds to the phase hysteresis introduced by the cancellation cable.

[0038] For example, assuming a frequency of 10MHz, the transmission parameter matrix of the transmission line connected to position 1 is calculated. And the frequency domain voltage response vector measured at the instrument port Current response vector First, generate the de-embedding inverse matrix: Then perform a left multiplication operation: actual voltage Real current As can be seen from this example, although the measured value is and However, calculations revealed that the voltage actually reaching the meter port had undergone phase shift, and both the current magnitude and phase had changed.

[0039] Perform complex division on the actual voltage vector and the actual current vector of the port, calculate the equivalent complex impedance of the port at each frequency point, and fill in the multi-port impedance coupling matrix according to the port number index order.

[0040] Impedance analysis, based on the complex form of Ohm's law in the frequency domain, processes the data at each scanned frequency point. For the... For each port, extract the corresponding actual voltage vector of the port. With the real current vector Performing complex division operation yields the port equivalent complex impedance at that frequency. The principle behind the calculation formula is as follows: , in, Indicates the first Each port is at frequency The equivalent complex impedance of the port is given below, in ohms. and These represent the magnitudes of the actual voltage and current, respectively. and These represent the phase angles of the actual voltage and current, respectively. The real part of the calculation result represents the equivalent resistance of the port, including contact resistance and internal circuit losses. The imaginary part of the calculation result represents the equivalent reactance of the port; positive values ​​indicate inductive properties, and negative values ​​indicate capacitive properties. Finally, a dimension is created... The three-dimensional data volume, in which The total number of table positions. This represents the total number of frequency sweep points. For each frequency point, the calculated value is determined based on the table port number. The self-impedance elements are filled to the diagonal positions of the matrix, and the mutual impedance values ​​calculated through mutual inductance coupling are filled to the off-diagonal positions, thus constructing a complete multi-port impedance coupling matrix. For example... Figure 2 As shown, the shades of gray represent the magnitude of the impedance modulus. The diagonal area reflects the equivalent self-impedance of each port, while the off-diagonal area reveals the mutual impedance coupling strength between different ports via cables and spatial stray parameters.

[0041] For example, it is known V, A. Perform complex division: To eliminate the imaginary part of the denominator, both the numerator and denominator are multiplied by the conjugate of the denominator. : , , Calculation results show that at a frequency of 10MHz, the port of the energy meter exhibits approximately The resistance characteristics and The capacitive reactance characteristics. (The complex number...) Fill in the diagonal element position corresponding to the first position in the multi-port impedance coupling matrix. This value accurately reflects the load characteristics of the meter at this frequency, providing a basis for calculating whether resonance has occurred.

[0042] Optionally, the step of extracting the intrinsic resonant frequency table and intrinsic mode vector set using eigenvalues ​​includes: Perform a similar diagonalization transformation operation on the multi-port impedance coupling matrix at each frequency sweep point to decouple and generate a diagonalized modal impedance matrix and a transformation characteristic matrix; The goal is to decouple a physically coupled multiport network into a set of mathematically independent "virtual modal ports" through mathematical transformation. The frequency-varying multiport impedance coupling matrix is ​​denoted as... Traverse every discrete frequency point within the sweep range. For the current frequency Perform the complex field similarity diagonalization transformation operation. Mathematically, this operation is equivalent to solving the eigenvalue decomposition problem of a matrix, aiming to find a transformation basis such that the impedance matrix under this basis is in diagonal form. The operation follows the linear algebraic transformation formula: , in, This represents the diagonalized modal impedance matrix. It is a... A diagonal matrix whose off-diagonal elements are all zero, and whose diagonal elements are... These are called characteristic roots. Physically, each characteristic root... Represents the first The equivalent input impedance of a certain inherent oscillation mode. This represents the multi-port impedance coupling matrix at the current frequency. This represents the transformation characteristic matrix. It is composed of... of The column vectors are composed of linearly independent eigenvectors. A square matrix. Physically, a matrix... Each column The first one is described The voltage / current distribution ratio of a mode at each physical port, i.e., the mode shape. This represents the inverse matrix of the transformation characteristic matrix. Through this operation, a matrix describing the magnitude of each modal impedance is obtained at each frequency point. and a description of each mode shape .

[0043] For example, suppose a test has two port numbers (Port1, Port2) and its multiport impedance coupling matrix is ​​at a scan frequency of 15MHz. The matrix shows that there are two ports. Mutual impedance coupling. Perform similarity diagonalization transformation operation: solve the characteristic equation. We obtain two eigenvalues: , The corresponding feature vector is , Therefore, the generated diagonalized modal impedance matrix The generated transformation feature matrix Physically, mode 1 represents the "common mode" of two oscillating points in phase, and mode 2 represents the "differential mode" of two oscillating points in opposite phase. At this point, the physical coupling is decoupled into two independent modes.

[0044] Search for local minima of the amplitude of the diagonal elements in the diagonalized modal impedance matrix, extract the frequency points to generate an eigenre resonant frequency table, and extract column vectors from the transformed feature matrix to construct an eigenmode vector group.

[0045] In circuit theory, when series resonance occurs, the circuit exhibits pure resistivity and its impedance magnitude reaches a minimum. At this point, the circuit is most sensitive to external excitation signals and has the weakest immunity to disturbances. Therefore, the "impedance amplitude minimum search method" is used to locate the resonance point. Along the frequency axis, each diagonal element in the diagonalized modal impedance matrix is ​​traced. modulus The trajectory of change. When a certain frequency point is detected. When the impedance magnitude at a given frequency point is less than the impedance magnitudes of its adjacent left and right frequency points, that point is determined to be a local minimum point in amplitude. All searched frequencies... Record these in a list to generate an eigenresonant frequency table. Then, based on each... By tracing back through the index in the scanned data, the transformation feature matrix corresponding to that frequency point is found. And extract the characteristic roots that resonate from them. The corresponding number Column vectors. These column vectors are defined as eigenmode vectors, which describe the voltage standing wave distribution at the resonant frequency. The set of all extracted column vectors constitutes the eigenmode vector set.

[0046] For example, a scan analysis of "Mode 2" is performed in the range of 10MHz to 20MHz. Assume... modulus The data as a function of frequency are as follows: at 14.9MHz, At 15.0MHz, At 15.1MHz, The frequency 15.0 MHz was identified as a local minimum in amplitude, therefore "15.0 MHz" was added to the intrinsic resonant frequency table. Simultaneously, the transformation characteristic matrix at 15.0 MHz was consulted. Extracting the corresponding The second column vector . This vector The intrinsic mode vector set is stored. This indicates that a strong differential mode resonance occurs at the multi-terminal when the interference frequency is 15.0 MHz, and the voltage fluctuations of the two terminals are in opposite directions. This information will guide the pulse generator to perform a tuning attack specifically targeting 15.0 MHz.

[0047] Optionally, the extraction of the optimal resonant frequency includes: The modal space projection operation is performed on the multi-port impedance coupling matrix using the intrinsic mode vector set to generate the modal impedance frequency response curve, and the half-power bandwidth value of the modal impedance frequency response curve is calculated. In a physical sense, each vector in the intrinsic mode vector set represents a specific current / voltage distribution pattern. First, the first vector in the intrinsic mode vector set is called... vectors As a projection operator, the multi-port impedance coupling matrix is ​​traversed across all scanning frequencies. Projected onto by In the defined modal space, this actually involves extracting the corresponding modal impedance matrix from the diagonalized modal impedance matrix. diagonal elements In terms of frequency Using the horizontal axis as the modulus of the diagonal elements Using the vertical axis as the plotting axis, construct the first... The modal impedance frequency response curves for each mode are presented. These curves reflect the trend of equivalent impedance changing with frequency under a specific oscillation mode. Next, for each resonant frequency recorded in the intrinsic resonant frequency table... Calculate the half-power bandwidth value on the corresponding modal impedance frequency response curve. Due to series resonance, the half-power point is defined as the impedance magnitude rising to the resonant point. The frequency position is determined by multiples of the resonant frequency. The calculation logic is as follows: Lock the resonant frequency. impedance magnitude at .Towards Low-frequency side search, find the first one that satisfies frequency points .Towards High-frequency side search to find the first one that satisfies frequency points Calculate the half-power bandwidth value. .

[0048] For example, suppose we analyze the first-order mode. On the modal impedance frequency response curve, the impedance magnitude reaches a local minimum at a frequency of 15 MHz. Set the search threshold to... The scan curve data revealed that at 14.95MHz, the impedance modulus was [value missing]. At 15.05MHz, the impedance magnitude is The half-power bandwidth of this mode at 15MHz was calculated. .

[0049] The half-power bandwidth value is used to perform a ratio calculation with the intrinsic resonant frequency table to generate a modal damping ratio sequence, and the minimum value index in the modal damping ratio sequence is locked to extract the optimal resonant frequency.

[0050] The optimal attack decision is based on second-order oscillation theory, evaluating each identified resonant mode using either "sharpness" or "quality factor." Physically, a smaller damping ratio results in a sharper resonant peak, stronger energy storage capacity at that frequency, and a higher transient overvoltage when subjected to pulse impacts. Therefore, it is the most threatening frequency for resisting disturbance testing. Each intrinsic resonant frequency is read. and its corresponding half-power bandwidth value The modal damping ratio is calculated using the following formula. : , in, The modal damping ratio is a dimensionless value derived from the second-order frequency domain characteristic description in classical control theory. For small damping, the damping ratio is approximately equal to the ratio of half-power bandwidth to twice the center frequency. The half-power bandwidth value is expressed in Hertz or Megahertz, and the unit is consistent with that of the denominator. The intrinsic resonant frequency table contains frequency values ​​in Hertz or Megahertz. Calculations are performed for all resonant frequency points, and the results are stored sequentially in a modal damping ratio sequence. Finally, a minimum value search algorithm is executed, traversing the sequence to find the element with the smallest value and its index position. The intrinsic resonant frequency corresponding to this index is determined as the optimal resonant frequency. Figure 3 As shown in the figure, each data point represents an eigenmode, and the frequency corresponding to the data point with the smallest damping ratio is locked as the most threatening optimal resonance frequency.

[0051] For example, suppose two potential resonance points are identified, and a decision needs to be made as to which one is more dangerous. Resonance point A: frequency Calculated bandwidth Calculate the damping ratio: Resonance point B: frequency ,bandwidth Calculate the damping ratio: Comparison revealed This indicates that the damping at resonance point B is minimal, and energy dissipation is slow. Once excited, its oscillation amplitude will far exceed that of resonance point A. Therefore, by locking the index of resonance point B, 15MHz is extracted and marked as the optimal resonance frequency.

[0052] Optionally, the synchronous application of an electrical fast transient pulse group to all positions includes: The optimal resonant frequency is written to the digital timing controller of the electric fast transient pulse generator, and clock division calculation is performed to reconstruct the single pulse repetition period parameters. The aim is to configure the core "heart" of the pulse generator, namely the digital timing controller, so that the frequency of its output pulse sequence precisely matches the resonance point. The digital timing controller internally maintains a high-precision reference clock source. When the controller receives the optimal resonance frequency value through the bus interface, it activates the internal frequency division logic unit. The single-pulse repetition period parameter is calculated according to the following frequency division formula: , in, This represents the single-pulse repetition period parameter, which is the target count value of the internal counter of the controller. It is the digital basis for reconstructing the pulse period. This indicates the hardware reference clock frequency of the digital timing controller, measured in Hertz. This value is determined by the hardware crystal oscillator, typically 200MHz or 500MHz, to ensure nanosecond-level timing accuracy. This indicates the optimal resonant frequency for writing, expressed in Hertz. This indicates the floor function, ensuring the counting parameter is an integer. After calculation, the controller will... Loaded into a pulse-triggered timer, thereby ensuring that the time interval between each generated electrical fast transient pulse is exactly equal to the reciprocal of the resonant period.

[0053] For example, assume the reference clock frequency of the digital timing controller The extracted optimal resonant frequency The controller performs the calculations: This means that the controller generates a trigger signal every 20 reference clock cycles. This 100ns cycle corresponds exactly to a 10MHz frequency, thus achieving a physical reconstruction of the optimal resonant frequency.

[0054] Extract the imaginary part of the diagonal elements of the multi-port impedance coupling matrix at the optimal resonant frequency, calculate the compensation reactance parameters required to cancel the imaginary part, and generate capacitor array switching instructions and inductor array adjustment instructions as impedance matching control instructions. Access the multi-port impedance coupling matrix in memory, and extract the complex impedance elements corresponding to each port position on the diagonal of the matrix based on the index of the optimal resonant frequency. Read the imaginary part of the complex number. To ensure that interference energy is fed into the position port to the maximum extent possible without reflection, a conjugate matching network needs to be constructed, i.e., a compensating reactance needs to be introduced. Make Based on the imaginary part value The symbol is used to select the corresponding calculation formula to generate the required compensation reactance parameters: Case 1: If This indicates that the port is inductive and requires capacitor compensation. Calculate the required capacitor value. : Scenario 2: If This indicates that the port is capacitive and requires inductor compensation. Calculate the required inductance value. : . Pi This is the absolute value of the imaginary part. The specific capacitance value is then calculated. or inductance value Then, it is mapped to discrete levels supported by the impedance compensation distribution network hardware to generate binary control code. The control code for the capacitor network is encapsulated as a capacitor array switching instruction, and the control code for the inductor network is encapsulated as an inductor array adjustment instruction. These two are collectively referred to as impedance matching control instructions.

[0055] For example, suppose in At that time, the imaginary part of the impedance at a certain position port is... Determine if capacitor compensation is needed, and substitute it into the formula to calculate: Assume the capacitor array in the impedance compensation distribution network is controlled by an 8-bit relay with an accuracy of 10pF / bit. Quantize 100pF into binary code 00001010 and generate a capacitor array switching instruction containing this binary code.

[0056] The relay switch matrix in the driving impedance compensation distribution network is loaded with the impedance matching control command and triggers the high-voltage solid-state switch according to the single pulse repetition period parameter, synchronously outputting electrical fast transient pulse groups to all positions.

[0057] First, the generated impedance matching control command is sent to the impedance compensation distribution network via the control bus. The relay drive circuit within the network parses the command and activates the corresponding relay switch matrix. Due to the operating delay of mechanical relays, the main control unit performs a "debouncing delay" after sending the command to ensure that all relay contacts are stably closed and the physical matching network is complete. Subsequently, a "start" signal is sent to the electrical fast transient pulse generator. Driven by a trigger signal generated by a digital timing controller, the high-voltage solid-state switch inside the generator strictly follows the calculated single-pulse repetition period parameters for high-speed switching on and off. The energy from the high-voltage source is chopped into nanosecond-level pulses by the solid-state switch, passes through the tuned impedance compensation distribution network, and is finally synchronously coupled to all meter ports. At this point, due to frequency resonance and impedance matching, the pulse energy generates a voltage superposition at the meter ports in the form of a standing wave, achieving the most stringent level of immunity testing.

[0058] Optionally, the generation of capacitor array switching commands and inductor array adjustment commands includes: The sign polarity is determined based on the imaginary part value. When the polarity is positive, the inductive reactance to capacitive compensation value is calculated by performing a reciprocal transformation calculation using the optimal resonant frequency. When the polarity is negative, the capacitive reactance to inductive compensation value is calculated by performing a proportional transformation calculation to generate the target compensation element value. Based on the series resonance principle of AC circuits, that is, when the inductive reactance in the circuit... With resistance When the values ​​are equal but the signs are opposite, the total reactance is zero, and the energy transfer efficiency is highest. First, read the imaginary part of the diagonal element corresponding to the position in the multi-port impedance coupling matrix, denoted as... . judge The positive and negative polarities. Case 1: If This indicates that the port of the meter exhibits inductive behavior. To counteract this inductive reactance, an equivalent capacitive reactance must be connected in series. Utilizing the optimal resonant frequency... Perform the "inductive reactance to capacitive compensation value reciprocal transformation calculation". The calculation formula is as follows: , in, This indicates the value of the target compensation element, in farads. This represents the angular frequency corresponding to the optimal resonance frequency, expressed in radians per second. This represents the imaginary part of the diagonal element, which is positive and expressed in ohms. The capacitive reactance formula is... In order to compensate the reactance The modulus is equal to the inductive impedance to be eliminated. ,Right now Therefore, it is exported Scenario 2: If This indicates that the port of this meter exhibits capacitive reactance. To offset this capacitive reactance, an equivalent inductive reactance must be connected in series. Perform the "proportional transformation calculation from capacitive reactance to inductive compensation value". The calculation formula is as follows: , in, This indicates the value of the target compensation element, in Henry. This represents the absolute value of the imaginary part of the diagonal element, in ohms. The inductive reactance formula is... In order to compensate the reactance The modulus is equal to the capacitive reactance to be eliminated. ,Right now Therefore, it is exported .

[0059] For example, suppose that in a single test, the optimal resonant frequency is extracted. The imaginary part of the diagonal element of a certain table port was detected. Since the sign is positive, it is determined to be an inductive port, and the compensation capacitor needs to be calculated. Substitute into the formula: The target compensation element value is 200 picofarads. Conversely, if another port is detected... Since it is determined to be a capacitive port, the compensation inductance needs to be calculated. Substitute into the formula: The target compensation element value is 200 nanohenries.

[0060] The target compensation element values ​​are mapped to the impedance compensation distribution network hardware using binary encoding to generate high and low level bit sequences for the switching channel, which are then combined to construct capacitor array switching instructions and inductor array adjustment instructions.

[0061] Impedance compensation distribution network hardware integrates multi-stage relay arrays, typically combined using a binary weighted method, such as an 8-bit capacitor array, with a minimum step / resolution of [missing value]. The maximum value is First, read the component resolution parameters from the hardware configuration file. Then perform quantization calculations: , in, It is calculated or , This is the corresponding decimal integer code. Then, The data is converted to a binary string, with each bit corresponding to a channel in the relay driver circuit. A bit value of "1" represents a high level, and a bit value of "0" represents a low level. Finally, the bit sequence generated for the capacitor array is encapsulated as a capacitor array switching instruction, and the bit sequence generated for the inductor array is encapsulated as an inductor array adjustment instruction.

[0062] For example, assume that the capacitor compensation module in the impedance compensation distribution network has 8 control channels and its hardware resolution is set to 10pF. Perform quantization calculations: The decimal number 20 is converted to 8-bit binary code: 00010100. This means: Bit 2 is set to high; Bit 4 is set to high; the remaining channels are set to low. At this time, the total capacitance value = pF. The sequence 00010100 is packaged to construct the capacitor array switching instruction, ready to be sent to the hardware for execution. In this way, the theoretically required impedance matching parameters are synthesized with limited hardware resources.

[0063] Optionally, constructing the critical set of disturbance immunity parameters includes: Monitor the interval between two consecutive electrical fast transient pulse groups, record the start time of the interval, and broadcast the communication read command to all port positions; In the electrical fast transient burst test standard, the burst is applied in a "burst" form, such as a 15-millisecond pulse train followed by a 285-millisecond silence period, which is the "interval period." A hardware interrupt line connected to the "burst state output" of the electrical fast transient generator determines the start of the interval period when the signal transitions from high to low, and immediately starts a high-precision microsecond-level timer to record this moment. Subsequently, a trigger signal is sent to the communication interface control. This control uses the RS-485 bus or power line carrier channel of the multi-meter test bench to simultaneously send communication read commands to all connected meter ports using a broadcast address. This command typically selects the data item most sensitive to interference, such as "current combined total active energy," to ensure maximum detection of communication or metering chip malfunctions.

[0064] For example, assume the pulse group period is set to 300ms. When the clock reaches... At ms, the generator output stopped. Record this moment as ms. and in At ms, send the hexadecimal instruction sequence 68 AA AA AA AA AA AA 68 11 04 33 33 33 33 CS 16 to the bus.

[0065] An independent receive waiting window is opened for each table port. If no acknowledgment frame is received before the window is closed, the communication response flag is set to zero; otherwise, it is set to one. The communication processing middleware employs multi-threaded or non-blocking I / O technology, instantiating an independent receive waiting window for each physically connected port. This window is essentially a countdown timer with a set timeout value. The interval length must be less than the interval period, typically set between 200 and 500 milliseconds, to ensure that the judgment is completed before the next pulse group arrives. During the window period, the receive buffer of each port is monitored. Judgment logic 1: If the buffer receives a complete data frame that starts with a fixed frame header, ends with a fixed frame tail, and passes longitudinal redundancy check or cyclic redundancy check, the port is considered to be communicating normally, and the communication response flag corresponding to the table bit is set to logic "1". Judgment logic 2: If no data is received after the timer expires, or the received data fails verification and retry is ineffective, the port's communication function is considered to be interrupted and malfunctioning, and the communication response flag corresponding to the table bit is set to logic "0".

[0066] Traverse the communication response flags, lock the flag index that changes from one to zero, read the pulse group number, pulse repetition frequency and peak voltage from the generator register at the current time, and construct the set of critical parameters for immunity.

[0067] Failure analysis maintains two state arrays: Current_Flags and Last_Flags. It iterates through all tabletop port indices. Perform edge detection logic operations: , in, Represents the logical AND operation. When When true, it means the first The index number, which previously communicated normally, became uncommunicable for the first time after being subjected to the recent burst of pulses. This defines the "barrier immunity critical point." Once the index is locked... Immediately access the internal status register of the electrical fast transient pulse generator via SCPI commands or the Modbus protocol to read the three key physical quantities currently applied: Pulse sequence number: the pulse train number in the current test cycle; Pulse repetition frequency: the current actual output single pulse frequency; Peak voltage: the current high voltage setting value for the pulse. Match these three parameters with the table position index. Binding generates a structured record of immunity critical parameters and stores it in a non-volatile database, thereby constructing a complete set of immunity critical parameters.

[0068] For example, suppose a test is underway for the 50th burst of a voltage level of 2000V and a frequency of 5kHz. During the interval after the 49th burst, the communication response flag of position 5 is 1. During the interval after the 50th burst, the communication response flag of position 5 is found to have changed to 0. A logical judgment is executed: 1 AND 0 results in true, locking position 5 into a critical failure state. The generator register is immediately read to obtain the data: {Burst_ID:50,Freq:5000Hz,Voltage:2000V}. A parameter set entry is constructed: Critical_Set_Item={Meter_Index:05,Failure_Mode:“Comm_Loss”,Threshold_Params:[50,5000,2000]}. This means that the energy meter has reached its immunity limit after withstanding 50 bursts at 2000V and 5kHz.

[0069] Based on the same inventive concept, this invention also provides a multi-position electrical fast transient / burst immunity test system, such as... Figure 4 As shown, the system includes: The meter topology construction module is used to record the meter port number and mechanical installation location coordinates through a multi-meter test bench to construct the meter electrical topology diagram. The impedance coupling matrix generation module is used to apply a broadband sinusoidal scanning excitation voltage to the multi-position test bench, simultaneously use the position port to collect the frequency domain voltage response vector and current response vector, map the frequency domain voltage response vector and current response vector to the position electrical topology diagram to perform distributed parameter decoupling calculation, and generate a multi-port impedance coupling matrix. The intrinsic mode extraction module is used to perform complex domain eigenvalue decomposition on the multi-port impedance coupling matrix and extract the intrinsic resonant frequency table and intrinsic mode vector group using the eigenvalues. The optimal resonance frequency extraction module is used to calculate the modal damping ratio based on the intrinsic mode vector group, and extract the optimal resonance frequency from the intrinsic resonant frequency table when the modal damping ratio takes the minimum value. The pulse group synchronous application module is used to tune the pulse repetition frequency to the optimal resonant frequency through the electric fast transient pulse generator, and generate an impedance matching control command according to the multi-port impedance coupling matrix to synchronously apply the electric fast transient pulse group to all positions. The immunity critical parameter construction module is used to send communication read commands to all meter positions during the interval between two adjacent electrical fast transient pulse groups, collect meter readings and communication response flags, and extract the pulse group number, pulse repetition frequency and peak voltage when the first communication response flag is missing, and construct the immunity critical parameter set.

[0070] It should be noted that the functional division and information interaction between the various modules described above are logical, but in terms of physical implementation, they can be integrated on the same software platform or deployed in a distributed manner. The connections between them represent data flow and control flow, aiming to collaboratively achieve the objectives of this invention. The above descriptions are merely exemplary embodiments of this invention and should not be construed as limiting the scope of protection of this invention.

Claims

1. A multi-position electrical fast transient / burst immunity test method, characterized in that, The method includes: By recording the port number and mechanical installation coordinates of the multi-position test bench, an electrical topology diagram of the position is constructed. A broadband sinusoidal scanning excitation voltage is applied to the multi-position test bench, and the frequency domain voltage response vector and current response vector are acquired simultaneously using the position ports. The frequency domain voltage response vector and current response vector are mapped to the position electrical topology diagram for distributed parameter decoupling calculation, and a multi-port impedance coupling matrix is ​​generated. Perform complex domain eigenvalue decomposition on the multi-port impedance coupling matrix, and extract the intrinsic resonant frequency table and intrinsic mode vector group using the eigenvalues; The modal damping ratio is calculated based on the intrinsic mode vector set, and the optimal resonance frequency is extracted from the intrinsic resonant frequency table when the modal damping ratio reaches its minimum value. The pulse repetition frequency is tuned to the optimal resonant frequency by an electric fast transient pulse generator, and an impedance matching control command is generated according to the multi-port impedance coupling matrix to synchronously apply an electric fast transient pulse group to all positions. During the interval between two consecutive electrical fast transient pulse groups, a communication read command is sent to all meter positions to collect meter readings and communication response flags. When the first communication response flag is missing, the pulse group number, pulse repetition frequency and peak voltage are extracted to construct a set of critical parameters for immunity.

2. The multi-position electrical fast transient / burst immunity test method according to claim 1, characterized in that, The construction of the tabletop electrical topology diagram includes: The multi-position test bench sequentially injects identification pulse signals into the position ports, records the position port number and mechanical installation position coordinates according to the response order, and generates a position number coordinate lookup table. Based on the coordinate lookup table of the table position number, the distance between adjacent coordinates and the connection sequence of the port are extracted, and the table position electrical topology diagram is constructed with the table position number as the node and the connection sequence as the edge.

3. The multi-position electrical fast transient / burst immunity test method according to claim 1, characterized in that, The generation of the multi-port impedance coupling matrix includes: The multi-position test bench is controlled to output a broadband sinusoidal scanning excitation voltage, and a fast Fourier transform is performed on the time-domain sampled data to extract the fundamental amplitude and phase to generate frequency-domain voltage response vector and current response vector. Based on the electrical topology diagram of the table, the node connection distance and cable characteristic impedance are analyzed, and a transmission line transmission parameter matrix is ​​constructed for the distributed inductance and distributed capacitance of the cable. The inverse transmission matrix de-embedding operation is performed on the frequency domain voltage response vector and the current response vector using the transmission line transmission parameter matrix. After eliminating the cable transmission effect, the port equivalent impedance is extracted to generate a multi-port impedance coupling matrix.

4. The multi-position electrical fast transient / burst immunity test method according to claim 3, characterized in that, The generation of the multi-port impedance coupling matrix includes: Perform matrix inversion on the transmission line transmission parameter matrix to generate a de-embedding inverse matrix, and perform left matrix multiplication on the de-embedding inverse matrix with the frequency domain voltage response vector and the current response vector to generate the actual voltage vector and the actual current vector of the position port. Perform complex division on the actual voltage vector and the actual current vector of the port, calculate the equivalent complex impedance of the port at each frequency point, and fill in the multi-port impedance coupling matrix according to the port number index order.

5. The multi-position electrical fast transient / burst immunity test method according to claim 1, characterized in that, The extraction of the intrinsic resonant frequency table and intrinsic mode vector group using eigenvalues ​​includes: Perform a similar diagonalization transformation operation on the multi-port impedance coupling matrix at each frequency sweep point to decouple and generate a diagonalized modal impedance matrix and a transformation characteristic matrix; Search for local minima of the amplitude of the diagonal elements in the diagonalized modal impedance matrix, extract the frequency points to generate an eigenre resonant frequency table, and extract column vectors from the transformed feature matrix to construct an eigenmode vector group.

6. The multi-position electrical fast transient / burst immunity test method according to claim 1, characterized in that, The extraction of the optimal resonance frequency includes: The modal space projection operation is performed on the multi-port impedance coupling matrix using the intrinsic mode vector set to generate the modal impedance frequency response curve, and the half-power bandwidth value of the modal impedance frequency response curve is calculated. The half-power bandwidth value is used to perform a ratio calculation with the intrinsic resonant frequency table to generate a modal damping ratio sequence, and the minimum value index in the modal damping ratio sequence is locked to extract the optimal resonant frequency.

7. The multi-position electrical fast transient / burst immunity test method according to claim 1, characterized in that, The synchronous application of electrical fast transient pulse groups to all positions includes: The optimal resonant frequency is written to the digital timing controller of the electric fast transient pulse generator, and clock division calculation is performed to reconstruct the single pulse repetition period parameters. Extract the imaginary part of the diagonal elements of the multi-port impedance coupling matrix at the optimal resonant frequency, calculate the compensation reactance parameters required to cancel the imaginary part, and generate capacitor array switching instructions and inductor array adjustment instructions as impedance matching control instructions. The relay switch matrix in the driving impedance compensation distribution network is loaded with the impedance matching control command and triggers the high-voltage solid-state switch according to the single pulse repetition period parameter, synchronously outputting electrical fast transient pulse groups to all positions.

8. The multi-position electrical fast transient / burst immunity test method according to claim 7, characterized in that, The generated capacitor array switching command and inductor array adjustment command include: The sign polarity is determined based on the imaginary part value. When the polarity is positive, the inductive reactance to capacitive compensation value is calculated by performing a reciprocal transformation calculation using the optimal resonant frequency. When the polarity is negative, the capacitive reactance to inductive compensation value is calculated by performing a proportional transformation calculation to generate the target compensation element value. The target compensation element values ​​are mapped to the impedance compensation distribution network hardware using binary encoding to generate high and low level bit sequences for the switching channel, which are then combined to construct capacitor array switching instructions and inductor array adjustment instructions.

9. The multi-position electrical fast transient / burst immunity test method according to claim 1, characterized in that, The set of critical parameters for disturbance resistance includes: Monitor the interval between two consecutive electrical fast transient pulse groups, record the start time of the interval, and broadcast the communication read command to all port positions; An independent receive waiting window is opened for each table port. If no acknowledgment frame is received before the window is closed, the communication response flag is set to zero; otherwise, it is set to one. Traverse the communication response flags, lock the flag index that changes from one to zero, read the pulse group number, pulse repetition frequency and peak voltage from the generator register at the current time, and construct the set of critical parameters for immunity.

10. A multi-position electrical fast transient / burst immunity test system, applied to the multi-position electrical fast transient / burst immunity test method as described in any one of claims 1-9, characterized in that, The system includes: The meter topology construction module is used to record the meter port number and mechanical installation location coordinates through a multi-meter test bench to construct the meter electrical topology diagram. The impedance coupling matrix generation module is used to apply a broadband sinusoidal scanning excitation voltage to the multi-position test bench, simultaneously use the position port to collect the frequency domain voltage response vector and current response vector, map the frequency domain voltage response vector and current response vector to the position electrical topology diagram to perform distributed parameter decoupling calculation, and generate a multi-port impedance coupling matrix. The intrinsic mode extraction module is used to perform complex domain eigenvalue decomposition on the multi-port impedance coupling matrix and extract the intrinsic resonant frequency table and intrinsic mode vector group using the eigenvalues. The optimal resonance frequency extraction module is used to calculate the modal damping ratio based on the intrinsic mode vector group, and extract the optimal resonance frequency from the intrinsic resonant frequency table when the modal damping ratio takes the minimum value. The pulse group synchronous application module is used to tune the pulse repetition frequency to the optimal resonant frequency through the electric fast transient pulse generator, and generate an impedance matching control command according to the multi-port impedance coupling matrix to synchronously apply the electric fast transient pulse group to all positions. The immunity critical parameter construction module is used to send communication read commands to all meter positions during the interval between two adjacent electrical fast transient pulse groups, collect meter readings and communication response flags, and extract the pulse group number, pulse repetition frequency and peak voltage when the first communication response flag is missing, and construct the immunity critical parameter set.

Images