Multi-dimensional electromagnetic compatibility test system and method for flexible direct current transmission power module

Abstract

The invention belongs to the field of flexible direct-current transmission power module tests, and discloses a multi-dimensional electromagnetic compatibility test system and method for a flexible direct-current transmission power module, and the method is characterized in that a dynamic power grid simulation unit simulates the electrical stress of the power module under a complex working condition by reproducing power grid limit faults such as direct-current short circuit and alternating-current harmonic waves; the broadband interference injection unit is used for superposing multi-band electromagnetic interference to simulate a composite interference scene according to the noise characteristics of the IGBT / IGCT switching process; the multi-physical field monitoring unit synchronously acquires key parameters such as electromagnetic field intensity, signal transmission, temperature rise and vibration, and analyzes module response under the action of multiple stress coupling in real time. According to the system, cooperative loading of power grid faults and noise is realized, limitation of a single interference source and a simple scene in a traditional test is broken through based on multi-physics field data fusion analysis, and the comprehensive evaluation precision of the anti-interference capability, the operation reliability and the safety of the power module in an extreme electromagnetic environment is improved.

Description

Technical Field

[0001] This invention belongs to the field of power electronic equipment reliability testing technology, specifically relating to the testing of flexible DC power transmission modules, and particularly to a multi-dimensional electromagnetic compatibility testing system and method for flexible DC power transmission modules. Background Technology

[0002] As the global energy structure accelerates its transition to renewable energy, the proportion of fluctuating power sources such as wind and solar power in the power grid continues to rise. Flexible DC transmission technology, with its advantages such as four-quadrant operation and independent control of active and reactive power, has become a key technology for achieving efficient interconnection and stable transmission of large-scale renewable energy across regions, playing a core role in the construction of new power systems.

[0003] However, as the core unit of the flexible DC transmission converter valve, the power module faces multiple challenges in its operating environment, including high voltage levels, high switching frequencies, and complex operating conditions. Existing electromagnetic compatibility (EMC) testing methods mostly focus on electrical performance verification or only test single interference sources and simple scenarios. They struggle to simulate extreme grid fault conditions such as DC-side short circuits and AC-side harmonic disturbances, and are even less capable of effectively assessing the combined effects of multiple interference sources. This limitation makes it impossible to accurately determine the power module's anti-interference capability in real-world complex electromagnetic environments.

[0004] It is evident that existing testing methods cannot simulate complex power grid operating conditions and multi-dimensional electromagnetic compatibility conditions caused by the superposition of multiple interference sources, making it impossible to accurately assess the reliability and safety of power modules and ensuring the stable operation of flexible DC transmission systems. Summary of the Invention

[0005] This invention provides a multi-dimensional electromagnetic compatibility (EMC) test system and method for flexible DC transmission power modules. This method can simulate complex power grid operating conditions and multi-dimensional EMC conditions caused by the superposition of multiple interference sources, accurately assess the reliability and safety of the power modules, and ensure the stable operation of the flexible DC transmission system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A multi-dimensional electromagnetic compatibility test system for a flexible DC power transmission module includes a dynamic power grid simulation unit, a broadband interference injection unit, and a multi-physics field monitoring unit; the dynamic power grid simulation unit, the broadband interference injection unit, and the multi-physics field monitoring unit are respectively connected to the flexible DC power transmission module; The dynamic power grid simulation unit is used to simulate the combined interference scenarios of power grid faults and disturbances, so that the flexible DC transmission power module can be presented as working in a complex power grid environment. A wideband interference injection unit is used to simulate noise during the switching process of IGBT / IGCT in flexible DC power transmission modules, in order to simulate various electromagnetic interference scenarios; A multi-physics monitoring unit is used to monitor the performance parameters of the flexible DC power transmission module during the test process; the performance parameters include electromagnetic field strength, signal transmission integrity, module temperature rise and mechanical vibration; the performance parameters are used to evaluate the comprehensive performance of the flexible DC power transmission module under multiple stresses.

[0007] Furthermore, the dynamic power grid simulation unit includes an IGBT fault generator, an FPGA harmonic controller, a nonlinear load module, and a bipolar redundancy switching device, wherein: The IGBT fault generator is connected to the bipolar redundancy switching device. The IGBT fault generator is connected to the FPGA harmonic controller; The FPGA harmonic controller is connected to the nonlinear load module; The IGBT fault generator and the bipolar redundancy switching device are respectively connected to the IGBT module of the flexible DC power transmission module. The FPGA harmonic controller is connected to a digital simulation platform; The digital simulation platform is used to transmit fault waveform parameters and harmonic control parameters to the FPGA harmonic controller. The FPGA harmonic controller is used to output a drive signal to the IGBT fault generator according to the fault waveform parameters to control the IGBT module of the flexible DC power transmission module to switch to short-circuit state; and to send preset harmonic components to the nonlinear load module according to the harmonic control parameters to simulate the resonant overvoltage condition of new energy grid connection. The bipolar redundancy switching device is used to form a fault response control loop with the IGBT module of the flexible DC power transmission module after the IGBT module switches to a short-circuit state, so that the IGBT module of the flexible DC power transmission module switches to a unipolar operation mode.

[0008] Furthermore, the IGBT fault generator adopts a three-level topology; the nonlinear load module simulates the resonant overvoltage condition of new energy grid connection by integrating an RLC resonant circuit and a switching matrix.

[0009] Furthermore, the broadband interference injection unit includes a pulse group simulator, a π-type coupling network, a log-periodic antenna array, and an impedance matching circuit; The pulse group simulator is connected to the π-type coupling network; The π-type coupling network is connected to the power port of the flexible DC transmission power module; The log-periodic antenna array constructs a spatial radiation field; The π-type coupling network and the impedance matching circuit are respectively connected to the spatial radiation field; The pulse group simulator is used to transmit the generated predefined waveform to the π-type coupled network; The π-type coupling network is used to couple a predefined waveform to the power port of the flexible DC transmission power module; The impedance matching circuit monitors the reflection coefficient of the space radiation field in real time and performs dynamic parameter calibration on the reflection coefficient, feeding back the calibrated reflection coefficient to the space radiation field.

[0010] Furthermore, the pulse group simulator adopts an avalanche transistor series structure; the π-type coupling network adopts an LCR composite structure; and the impedance matching circuit includes a variable inductor and an RF transformer.

[0011] Furthermore, the multiphysics monitoring unit includes an electromagnetic probe array, an FBG fiber optic sensor, a MEMS vibration sensor, and a mixed signal analyzer; the electromagnetic probe array, the FBG fiber optic sensor, and the MEMS vibration sensor are respectively connected to the mixed signal analyzer; The electromagnetic probe array is used to collect electromagnetic radiation data; The FBG fiber optic sensor is used to collect temperature field data; The MEMS vibration sensor is used to monitor mechanical vibration data; The mixed signal analyzer is used to obtain the electromagnetic field strength based on electromagnetic radiation data and to obtain the module temperature rise based on temperature field data.

[0012] Furthermore, the electromagnetic probe array is connected to the mixed signal analyzer via a signal conditioning module; the FBG fiber optic sensor is connected to the mixed signal analyzer via a wavelength division multiplexer.

[0013] Furthermore, the mixed signal analyzer is connected to an edge computing node, which is used to reconstruct a three-dimensional field distribution model based on electromagnetic field strength, module temperature rise, and mechanical vibration. The reconstructed three-dimensional field distribution model is then compared with a pre-built digital twin model to obtain an evaluation result.

[0014] Furthermore, the electromagnetic probe array includes a near-field magnetic field probe and an electric field probe.

[0015] A multi-dimensional electromagnetic compatibility (EMC) testing method for a flexible DC power transmission module, based on the aforementioned multi-dimensional EMC testing system for the flexible DC power transmission module, includes: A dynamic power grid simulation unit is used to simulate the combined interference scenarios of power grid faults and disturbances, so that the flexible DC transmission power module can be made to exhibit the working state in a complex power grid environment. A wideband interference injection unit is used to simulate the noise during the switching process of IGBT / IGCT in a flexible DC power transmission module, in order to simulate various electromagnetic interference scenarios; A multi-physics monitoring unit was used to monitor the performance parameters of the flexible DC power transmission module during the test. The performance parameters included electromagnetic field strength, signal transmission integrity, module temperature rise, and mechanical vibration. These performance parameters were used to evaluate the comprehensive performance of the flexible DC power transmission module under multiple stresses.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a multi-dimensional electromagnetic compatibility (EMC) testing system for flexible DC transmission power modules. The system integrates a dynamic power grid simulation unit, a broadband interference injection unit, and a multi-physics field monitoring unit. The dynamic power grid simulation unit simulates the electrical stress of the power module under complex operating conditions by reproducing extreme power grid faults such as DC short circuits and AC harmonics. The broadband interference injection unit targets the noise characteristics of IGBT / IGCT switching processes, superimposing multi-band electromagnetic interference to simulate composite interference scenarios. The multi-physics field monitoring unit simultaneously collects key parameters such as electromagnetic field strength, signal transmission, temperature rise, and vibration, and analyzes the module response under multiple stress coupling effects in real time. This system achieves, for the first time, the coordinated loading of power grid faults and noise, and based on multi-physics field data fusion analysis, overcomes the limitations of traditional tests with single interference sources and simple scenarios. It significantly improves the comprehensive evaluation accuracy of the power module's anti-interference capability, operational reliability, and safety under extreme electromagnetic environments, providing key technical support for the stable operation of flexible DC transmission systems.

[0017] This invention also provides a multi-dimensional electromagnetic compatibility (EMC) testing method for flexible DC power transmission modules. Based on the aforementioned multi-dimensional EMC testing system for flexible DC power transmission modules, this method constructs a multi-dimensional EMC testing process through the coordinated implementation of three stages: dynamic grid simulation, broadband interference injection, and multi-physics field monitoring. First, the dynamic grid simulation unit actively generates extreme fault conditions such as DC short circuits and AC harmonics, realistically reproducing the electrical stress environment of the power module under grid disturbances. Second, the broadband interference injection unit accurately loads the noise spectrum of the switching process of insulated gate bipolar transistors / integrated gate commutated thyristors (IGBTs / IGCTs), realizing the spatiotemporal superposition of multi-band electromagnetic interference and overcoming the limitations of a single interference source. Finally, the multi-physics field monitoring unit simultaneously captures cross-dimensional parameters such as electromagnetic field strength, signal integrity, temperature rise, and vibration, revealing the multi-stress coupling mechanism of electrical-thermal-mechanical stresses. By loading grid faults and noise in a step-by-step and collaborative manner, and based on multi-physics parameter correlation analysis, we have achieved for the first time accurate simulation and comprehensive evaluation of composite interference scenarios. This completely solves the core defect of traditional testing that cannot simulate the superposition effect of multiple sources, significantly improves the verification accuracy of the reliability and safety of power modules under extreme electromagnetic environments, and provides methodological support for the stable operation of flexible DC transmission systems. Attached Figure Description

[0018] Figure 1 An integrated schematic diagram of a multi-dimensional electromagnetic compatibility test system for a flexible DC power transmission module provided in an embodiment of the present invention; Figure 2 This is a connection diagram of the dynamic power grid simulation unit provided in an embodiment of the present invention; Figure 3 This is a connection diagram of the broadband interference injection unit provided in an embodiment of the present invention; Figure 4 This is a connection diagram of the multiphysics monitoring unit provided in an embodiment of the present invention; Figure 5 This is an architectural diagram of a multi-dimensional electromagnetic compatibility test system for a flexible DC power transmission module, provided as an embodiment of the present invention. Detailed Implementation

[0019] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0020] As described in the background section, most existing electromagnetic compatibility testing methods focus on verifying electrical performance or are limited to single interference sources and simple interference scenarios. They cannot simulate complex power grid faults and electromagnetic environments, such as extreme conditions like DC-side short circuits and AC-side harmonic disturbances, nor can they simulate the superposition effects of multiple interferences. This makes it difficult to accurately assess the electromagnetic interference problems that power modules may face in actual operation.

[0021] To address the aforementioned issues, this embodiment provides a multi-dimensional electromagnetic compatibility testing system for flexible DC transmission power modules. This system utilizes a combination of multi-level simulation and hardware simulation techniques to accurately reproduce complex power grid faults and electromagnetic environments, enabling a comprehensive evaluation of the performance stability of power modules in flexible DC transmission systems under complex electromagnetic environments.

[0022] To facilitate a better understanding of the technical solutions provided by this invention, the following technical terms are explained below: IGBT: Insulated Gate Bipolar Transistor, is a composite fully controllable voltage-driven power semiconductor device.

[0023] IGCT: Integrated Gate Commutated Thyristor, a new type of high-power semiconductor device developed based on gate turn-off thyristor technology.

[0024] LCR composite structure: a circuit structure consisting of an inductor (L), a capacitor (C), and a resistor (R).

[0025] FPGA (Field Programmable Gate Array) is a type of semi-custom digital integrated circuit.

[0026] RLC resonant circuit: A circuit composed of resistor (R), inductor (L) and capacitor (C) that will resonate at a specific frequency.

[0027] THD (Total Harmonic Distortion) is an indicator that measures the degree of distortion of the original signal by harmonic components.

[0028] FBG: FBG (Fiber Bragg Grating) is a fiber optic sensor, also known as a fiber Bragg grating sensor.

[0029] MEMS: MEMS (Micro-Electro-Mechanical System) vibration sensors are vibration sensors made based on micro-electro-mechanical system technology.

[0030] The Levenberg-Marquardt algorithm is an optimization algorithm for solving nonlinear least squares problems. It combines the advantages of the Gauss-Newton method and gradient descent and is widely used in curve fitting, parameter estimation, machine learning and other fields.

[0031] Power spectral density (PSD) is a physical quantity that describes the energy distribution of a random vibration signal in the frequency domain. PSD reflects the power (or energy) intensity of a random vibration signal at different frequencies and is an important tool for analyzing the characteristics of random vibration.

[0032] Improved FFT Inverse Transform Algorithm: The improved FFT (Fast Fourier Transform) inverse transform algorithm is an optimization of the traditional fast Fourier inverse transform algorithm, aiming to improve computational efficiency, reduce complexity, or enhance numerical stability.

[0033] DC: stands for Direct Current, which refers to current whose direction does not change with time.

[0034] ADC: Analog-to-Digital Converter, is an electronic device that converts continuous analog signals into discrete digital signals.

[0035] QAM: Quadrature Amplitude Modulation (QAM) is a technique that transmits digital signals by modulating the amplitude and phase of a carrier wave.

[0036] LISN: LISN (Line Impedance Stabilization Network) plays an important role in electromagnetic compatibility (EMC) testing.

[0037] QP value: The QP value (Quasi-Peak) is a measurement parameter used in electromagnetic compatibility testing to assess the level of electromagnetic interference (EMI).

[0038] RMS value: RMS (Root Mean Square) value is a mathematical method used to describe the effective amplitude of an AC signal (such as voltage, current, or power), and is widely used in engineering, physics, and signal processing.

[0039] HDF5 format: HDF5 (Hierarchical Data Format 5) is a file format for storing and managing large-scale scientific data, designed for the efficient organization, storage and access of complex datasets.

[0040] This embodiment provides a multi-dimensional electromagnetic compatibility (EMC) test system for a flexible DC power transmission module, comprising: a dynamic power grid simulation unit, a broadband interference injection unit, and a multiphysics field monitoring unit; all three units are connected to the flexible DC power transmission module under test. The dynamic power grid simulation unit simulates combined interference scenarios involving power grid faults and disturbances, allowing the flexible DC power transmission module to exhibit its operating state in a complex power grid environment. The broadband interference injection unit simulates noise during the IGBT / IGCT switching process in the flexible DC power transmission module; this noise is high-frequency noise, typically referring to random disturbances with frequencies above 1000Hz, to simulate various electromagnetic interference scenarios. The multiphysics field monitoring unit monitors the performance parameters of the flexible DC power transmission module during the test; these performance parameters include electromagnetic field strength, signal transmission integrity, module temperature rise, and mechanical vibration; these performance parameters are used to evaluate the comprehensive performance of the flexible DC power transmission module under multiple stresses.

[0041] The experimental system provided in this embodiment will be further described below with reference to the accompanying drawings: like Figure 1 As shown, this embodiment provides a multi-dimensional electromagnetic compatibility test system for a flexible DC power transmission module. The test system is divided into a main circuit layer, a signal coupling layer, a monitoring feedback layer, and a control center. The main circuit layer primarily employs a dynamic power grid simulation unit; the signal coupling layer primarily employs a broadband interference injection unit; the monitoring feedback layer primarily employs a multi-physics monitoring unit; and the control center includes a digital simulation platform and edge computing nodes. The specific structure and connection relationships are as follows: Dynamic power grid simulation unit: By integrating DC-side fault and AC-side harmonic disturbance modules, this system can simulate complex interference scenarios in the power grid. This approach more realistically reflects the operating status of the power module in a complex power grid environment, thus providing a more accurate electromagnetic compatibility assessment.

[0042] Wideband interference injection unit: Through an adjustable frequency harmonic generator, it simulates the noise during the switching process of IGBT / IGCT inside the power module, and then evaluates its impact on surrounding equipment and control systems.

[0043] Multiphysics Monitoring Unit: During testing, the combined testing of multiple physical fields, such as electromagnetic fields, temperature rise, and mechanical vibration, allows for a comprehensive evaluation of the power module's stability and anti-interference capabilities under multiple stresses. This comprehensive evaluation method reflects the module's overall performance under actual operating conditions, improving the reliability of test results.

[0044] like Figure 2 As shown, the dynamic power grid simulation unit specifically includes: IGBT fault generator: adopts a three-level topology and supports a short-circuit current rise rate of 10ns (maximum 50kA).

[0045] FPGA Harmonic Controller: Generates programmable distortion waveforms with THD of 0-30% based on an improved FFT inverse transform algorithm.

[0046] Nonlinear load module: integrates RLC resonant circuit and switching matrix, capable of simulating resonant overvoltage caused by grid connection of new energy sources.

[0047] Bipolar redundancy switching device: In the event of a fault, it can automatically switch to unipolar operation mode to maintain 50% power transmission capacity.

[0048] The digital simulation platform connects to the FPGA harmonic controller to transmit fault waveform parameters and harmonic control parameters.

[0049] The FPGA harmonic controller is connected to the IGBT fault generator (output drive signal) and the nonlinear load module (send harmonic components).

[0050] The IGBT fault generator is connected to the IGBT module of the flexible DC power transmission module (controlling short-circuit switching) and is also connected to the bipolar redundancy switching device.

[0051] The bipolar redundancy switching device is connected to the IGBT module of the flexible DC transmission power module to form a fault response loop.

[0052] The nonlinear load module receives harmonic commands from the FPGA harmonic controller to simulate resonant conditions.

[0053] The specific working principle is as follows: Fault simulation: The digital simulation platform sends fault waveform parameters to the FPGA harmonic controller. The FPGA harmonic controller drives the IGBT fault generator to control the power module IGBT to switch to a short-circuit state, simulating an IGBT fault.

[0054] Redundancy switching: After a short circuit is triggered, the bipolar redundancy switching device and the power module IGBT form a control loop to switch it to unipolar operation mode to achieve fault tolerance.

[0055] Resonance Simulation: The digital platform sends harmonic control parameters to the FPGA harmonic controller, which in turn controls the nonlinear load module to generate preset harmonics to simulate the resonant overvoltage condition of new energy grid connection.

[0056] like Figure 3 As shown, the broadband interference injection unit includes a pulse group simulator, a π-type coupling network, a log-periodic antenna array, and an impedance matching circuit, wherein: Pulse burst simulator: Composed of an avalanche transistor series structure, it is used to generate a 5kHz repetition frequency and a 5kV transient pulse, which is then used to simulate the switching spikes of power devices.

[0057] π-type coupling network: adopts LCR composite structure to achieve directional injection of common-mode / differential-mode interference in the DC-1GHz band, with insertion loss <1dB.

[0058] Log-periodic antenna array: operates in the 1-6 GHz frequency band, and achieves spatial field strength control (±2 dB uniformity) of QAM modulation interference through a vector signal generator.

[0059] Impedance matching circuit: including a variable inductor and an RF transformer, used to dynamically adjust the characteristic impedance of the injection path (matching accuracy 0.1Ω).

[0060] The pulse group simulator connects to a π-type coupled network to transmit predefined interference waveforms.

[0061] The π-type coupling network is directly connected to the power port of the flexible DC power transmission module, and is simultaneously coupled with the spatial radiation field constructed by the log-periodic antenna array.

[0062] Impedance matching circuits are connected to the space radiation field in real time to monitor and dynamically calibrate its reflection coefficient.

[0063] The specific working principle is as follows: Interference injection: A pulse group simulator generates a predefined interference waveform, which is then transmitted in two paths via a π-type coupling network. First, the conduction path: directly injected into the port of the power module to simulate interference conducted through cables; Second, radiation path: coupled to the space radiation field, and radiates electromagnetic interference through the antenna array.

[0064] Field calibration: The impedance matching circuit monitors the reflection coefficient of the radiation field in real time, dynamically adjusts the matching parameters to minimize reflection, ensures that the radiation field strength is accurate and controllable, and feeds back the calibration parameters to the radiation field to maintain stability.

[0065] like Figure 4 As shown, the multiphysics monitoring unit includes an electromagnetic probe array, an FBG fiber optic sensor, a MEMS vibration sensor, and a mixed-signal analyzer, wherein: Electromagnetic probe array: including near-field magnetic field probe (100kHz-3GHz) and electric field probe (10MHz-18GHz).

[0066] FBG fiber optic sensors: Distributed on the surface of the module under test (power module), with a spatial resolution of 16 points / cm. 2 Monitor the temperature rise gradient.

[0067] MEMS vibration sensor: acquires vibration spectrum from 5-2000Hz, sensitivity 0.04g 2 / Hz.

[0068] Mixed Signal Analyzer: Integrates a 12-bit ADC and high-speed cache, supporting simultaneous acquisition of 20 channels of signals.

[0069] The electromagnetic probe array is connected to a mixed-signal analyzer via a signal conditioning module to transmit electromagnetic radiation data. The FBG fiber optic sensor is connected to a mixed signal analyzer via a wavelength division multiplexer to transmit temperature field data. MEMS vibration sensors are directly connected to a mixed signal analyzer to transmit mechanical vibration data; The mixed-signal analyzer connects to edge computing nodes and outputs electromagnetic field strength, module temperature rise, and vibration data.

[0070] The specific working principle is as follows: First, data collection: The electromagnetic probe array captures electromagnetic radiation around the equipment, and the signal conditioning module filters out noise before transmitting it to the mixed signal analyzer. The FBG fiber optic sensor monitors the temperature field distribution by wavelength change, and the signal is sent to a mixed signal analyzer after being demodulated by a wavelength division multiplexer. MEMS vibration sensors acquire mechanical vibration spectra in real time and transmit them directly to a mixed signal analyzer.

[0071] The electromagnetic probe array, FBG fiber optic sensor, and MEMS vibration sensor all collect data and converge them to a mixed signal analyzer using wavelength division multiplexing technology.

[0072] Second, analysis and modeling: The mixed-signal analyzer converts raw data into physical quantities such as electromagnetic field strength and module temperature rise; Edge computing nodes fuse three types of data, use the Levenberg-Marquardt algorithm to reconstruct a three-dimensional multiphysics distribution model, compare the deviation with a preset digital twin model, and output the evaluation results of the power module.

[0073] This embodiment provides a multi-dimensional electromagnetic compatibility test system for flexible DC power transmission modules. The dynamic power grid simulation unit, broadband interference injection unit, and multi-physics field monitoring unit achieve coupled operating condition simulation through fiber optic synchronous triggering. The dynamic power grid simulation unit generates a fundamental fault signal; the broadband interference unit superimposes high-frequency disturbance components; and the multi-physics field monitoring unit provides real-time feedback of electromagnetic-thermal-mechanical coupling effects to form a closed-loop verification. The time synchronization accuracy of each unit is <30ns, meeting the timing requirements of GB / T 17626 series standards for composite operating condition testing.

[0074] Therefore, the multi-dimensional electromagnetic compatibility test system for the flexible DC power transmission module provided in this embodiment is implemented using the following technical means: I. Dynamic Power Grid Simulation Technology: The technical methods for simulating DC-side short-circuit faults are as follows: A fault generator employing an IGBT series topology achieves a short-circuit current waveform with a rise time on the order of 10 ns through gate drive timing control. Combined with line wave velocity dynamic calibration technology (accuracy 0.1%), it ensures that the impedance matching characteristics of the short-circuit propagation path are consistent with the actual power grid.

[0075] It integrates a bipolar operation redundancy design, automatically switching to unipolar operation mode when a fault occurs, maintaining 50% power transmission capacity to simulate real fault scenarios.

[0076] The technical methods for generating harmonic disturbances on the AC side are as follows: A real-time harmonic synthesis platform based on FPGA is constructed, and a modified inverse FFT algorithm is used to generate programmable distortion waveforms with THD of 0-30%. The fundamental and harmonic components are separated by wavelet packet transform to achieve directional enhancement of specific harmonics.

[0077] Configure a nonlinear load simulation module (including a resistive-inductive-capacitive composite circuit) to reproduce the resonant overvoltage phenomenon caused by the grid connection of new energy sources.

[0078] II. Wideband Interference Coupling Technology The technical methods for addressing the superposition of conducted interference are as follows: A DC-1GHz broadband coupled network was constructed, employing a π-type topology to achieve independent injection of common-mode / differential-mode interference. Insertion loss was controlled to <1dB to ensure high-frequency signal fidelity.

[0079] An integrated pulse group simulator is used to generate transient pulse groups with a repetition frequency of 5kHz and an amplitude of 5kV through a series avalanche transistors to simulate the voltage spike when the IGCT is turned off.

[0080] The technical means of constructing radiated interference are as follows: A 1-6 GHz radiation field is constructed using a log-periodic antenna array, and a vector signal generator is used to control the spatial field strength uniformity of QAM modulation interference (±2 dB).

[0081] A three-dimensional electromagnetic field distribution model is established in an anechoic chamber, and the field strength gradient is calculated using the boundary element method to achieve the coordinated simulation of the near-field and far-field radiation characteristics of the equipment.

[0082] III. Multiphysics Coupling Monitoring Technology: The technical means for real-time electromagnetic field sensing are as follows: An array-type monitoring network consisting of near-field magnetic field probes (100kHz-3GHz) and electric field probes (10MHz-18GHz) is deployed to locate electromagnetic radiation hot zones through time-domain synchronous acquisition.

[0083] The three-dimensional electromagnetic field distribution was reconstructed using an improved Levenberg-Marquardt optimization algorithm, achieving a spatial resolution of 5 mm.

[0084] The technical methods for multi-parameter synergistic analysis of electromechanical and thermal parameters are as follows: FBG fiber optic sensors (16 points / cm) are placed at key locations on the power module. 2 Monitor the temperature gradient and verify the hotspot distribution using infrared thermal imaging.

[0085] Vibrational spectra from 5 to 2000 Hz were acquired using MEMS accelerometers, and random vibration PSD analysis (0.04 g) was performed. 2 ( / Hz) to assess the reliability of mechanical connections.

[0086] In summary, this embodiment overcomes the limitations of traditional single-factor testing by combining dynamic power grid simulation, wideband interference coupling, and multi-dimensional monitoring technologies. For example, under the combined operating condition of a DC short circuit (50kA) superimposed with 2MHz radiated interference, this system can simultaneously trigger fault current generation and radiation field establishment, with a time delay error controlled within 30ns, providing a high-confidence test platform for the full-condition electromagnetic compatibility evaluation of power modules.

[0087] For example, the multi-dimensional electromagnetic compatibility testing system provided in this embodiment has been practically applied, and the specific implementation process is as follows: like Figure 5 As shown, this embodiment provides a multi-dimensional electromagnetic compatibility test system for flexible DC transmission power modules, which is used to evaluate the performance stability of power modules in flexible DC transmission systems under complex electromagnetic environments. The power module under test is a flexible DC transmission power module. The system includes a dynamic power grid simulation unit, a broadband interference injection unit, and a multi-physics monitoring unit.

[0088] In this embodiment, the dynamic power grid simulation unit integrates a DC-side fault generator: employing an IGBT series topology, it can output a short-circuit current with a rise time tr = 10ns, and an AC harmonic injector: based on the inverse FFT algorithm, it generates a programmable distortion waveform with THD = 0~30% to simulate actual faults and disturbances in the power grid. The dynamic power grid simulation unit can reproduce various complex faults occurring in the power grid, such as DC-side short circuits and AC-side voltage drops.

[0089] The broadband interference injection unit includes a high-frequency harmonic generator, a pulse group simulator, and other equipment for injecting common-mode and differential-mode interference. The frequency and amplitude of the high-frequency interference injection unit are adjustable. Combined with a conducted interference coupling network, it supports DC-1GHz signal injection with insertion loss <1dB. The radiated interference emission system uses a log-periodic antenna array with field strength uniformity of ±2dB (1-6GHz). Together, they constitute the broadband interference injection unit to simulate different electromagnetic interference scenarios.

[0090] The multi-physics monitoring unit employs an electromagnetic probe array, including a near-field magnetic field probe (100kHz-3GHz) and an electric field probe (10MHz-18GHz); distributed temperature sensing utilizes an FBG fiber optic sensor, achieving a measurement point density of 16 points / cm². 2 3D vibration acquisition: MEMS accelerometers are deployed at key mechanical support points. The multiphysics monitoring unit can monitor multiple parameters in real time, such as electromagnetic field strength, signal transmission integrity, module temperature rise, and mechanical vibration, and use them for subsequent analysis and evaluation.

[0091] This embodiment also provides a multi-dimensional electromagnetic compatibility (EMC) testing method for flexible DC power transmission modules, including: using a dynamic power grid simulation unit to simulate a combined interference scenario of power grid faults and disturbances, so that the flexible DC power transmission module exhibits its working state in a complex power grid environment; using a broadband interference injection unit to simulate noise during the IGBT / IGCT switching process in the flexible DC power transmission module, so as to simulate various electromagnetic interference scenarios; and using a multi-physics monitoring unit to monitor the performance parameters of the flexible DC power transmission module during the test process; the performance parameters include electromagnetic field strength, signal transmission integrity, module temperature rise, and mechanical vibration; the performance parameters are used to evaluate the comprehensive performance of the flexible DC power transmission module under multiple stresses.

[0092] The specific implementation process for multi-dimensional electromagnetic compatibility testing of flexible DC transmission power modules is as follows: I. Typical Multiphysics Coupling Experiment Outline: 1. Basic performance testing: Under interference-free conditions, the basic electrical parameters of the power module are first verified to ensure its normal operation. This stage of testing includes basic electrical performance parameters such as DC voltage, AC current, and switching frequency.

[0093] 2. Single-factor benchmarking: After basic performance testing, the following tests were performed using a wideband interference injection unit. (1) High-frequency interference test: Inject high-frequency harmonics (1kHz-10MHz) in different frequency ranges to evaluate the impact of high-frequency interference on the power module. The test includes monitoring the bypass switch malfunction rate and the distortion of the control signal.

[0094] (2) Conducted emission test: The module is placed on a metal ground plane, the LISN is connected to the DC bus, and the QP value is recorded using a spectrum analyzer.

[0095] (3) Radiated immunity test: Apply an electric field strength of 80-1000MHz to 30V / m in an anechoic chamber, and the functional performance of the module under test shall not be degraded by more than 5%.

[0096] 3. Multi-factor coupling test: By designing composite scenarios and monitoring the module's response under these extreme conditions, its anti-interference capability and stability are evaluated. Table 1 shows several typical composite scenarios: Table 1 shows typical composite scenarios.

[0097] 4. Extreme Environment Testing: EMC performance testing of the module was conducted under extreme environmental conditions, including high temperature and strong vibration. This test aims to verify the module's performance and stability under extreme environments such as high temperature, high humidity, and strong vibration. Typical environmental parameters for the test are shown in Table 2. Table 2 shows the typical environmental parameters for the test.

[0098] II. Standardized Procedure for Multiphysics Coupling Tests: 1. Test system initialization: (1) Hardware connection verification: Ⅰ. Check the impedance matching of the power circuit (target value <0.1Ω).

[0099] II. Calibrate the sensor network (synchronize the sampling rate of the electromagnetic probe / fiber optic cable / FBG).

[0100] (2) Software pre-configuration: Ⅰ. Load the digital twin model (activate the Simulink-Abaqus co-simulation interface).

[0101] II. Set the filtering parameters for the edge computing nodes (cutoff frequency according to GB / T17626.30 standard).

[0102] 2. Extreme operating condition test case: Experiment 1: Electromagnetic-thermal coupling performance test under transient short-circuit conditions: (1) Operation procedure: Ⅰ. Start the dynamic power grid simulation unit and preset the 50kA / 10ns short-circuit current waveform.

[0103] II. Synchronously activate the broadband interference unit (inject 100MHz-1GHz conducted interference).

[0104] III. The junction temperature gradient of the device is monitored using an FBG fiber optic array (sampling rate 1MHz).

[0105] (2) Key parameter collection: I. Short-circuit current peak value and timing.

[0106] II. Junction temperature rise rate (°C / μs).

[0107] III. Near-field radiation spectrum (30MHz-3GHz).

[0108] (3) Data processing and evaluation: I. Time-frequency analysis: Perform wavelet transform on current and temperature data to extract transient coupling features.

[0109] II. Performance Judgment: If the junction temperature gradient is >5℃ / μs and the spectrum exceeds the standard, the thermo-electromagnetic protection is deemed to have failed.

[0110] Experiment 2: Mechanical-Electrical Coupling Vibration Test under Harmonic Distortion Conditions: (1) Operation procedure: I. Inject 5th / 7th harmonics with THD=25% through the FPGA controller.

[0111] II. Start the MEMS vibration sensor array (bandwidth 5-2kHz).

[0112] III. Trigger the high-speed camera to record structural deformation (10kfps).

[0113] (2) Key parameter collection: I. Vibration acceleration RMS value.

[0114] II. Structural resonant frequency offset.

[0115] III. Current harmonic distortion rate.

[0116] (3) Data processing and evaluation: I. Modal Analysis: Identify the coupling relationship between the resonant point and the mechanical natural frequency through FFT.

[0117] II. Performance assessment: If the resonant frequency deviation is >5% and the vibration acceleration exceeds the standard, the structural stiffness needs to be optimized.

[0118] 3. Test Termination and Report Generation: (1) Data archiving: The original data is stored in HDF5 format (custom timestamp and working condition label).

[0119] (2) Output report: Generate multiphysics coupling matrix (electromagnetic-thermal-mechanical interaction coefficient table) and obtain test conclusions that conform to GB / T17626 series standards.

[0120] In summary, this invention provides a multi-dimensional electromagnetic compatibility testing system and method for flexible DC power transmission modules, which has the following advantages compared to existing testing methods: This test system accurately reproduces complex disturbance scenarios such as power grid faults and harmonic resonances through a dynamic power grid simulation unit, and achieves controllable injection of conducted and radiated electromagnetic interference through a broadband interference injection unit. Combined with a multi-physics monitoring unit for the coordinated acquisition and analysis of electromagnetic, thermal, and mechanical parameters, a highly simulated multi-stress coupling test environment is constructed. The closed-loop test mechanism driven by digital twins not only enables a comprehensive evaluation of the electromagnetic compatibility performance of power modules under extreme operating conditions, but also allows for real-time comparison of measured data and digital models through edge computing to reveal potential failure mechanisms. This significantly improves the coverage depth of the test scenario, the realism of interference simulation, and the ability to warn of performance degradation, providing key support for the development of highly reliable flexible DC equipment.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A multi-dimensional electromagnetic compatibility test system for a flexible DC power transmission module, characterized in that, It includes a dynamic power grid simulation unit, a broadband interference injection unit, and a multiphysics field monitoring unit; the dynamic power grid simulation unit, the broadband interference injection unit, and the multiphysics field monitoring unit are respectively connected to the flexible DC transmission power module; The dynamic power grid simulation unit is used to simulate the combined interference scenarios of power grid faults and disturbances, so that the flexible DC transmission power module can be presented as working in a complex power grid environment. A wideband interference injection unit is used to simulate noise during the switching process of IGBT / IGCT in flexible DC power transmission modules, in order to simulate various electromagnetic interference scenarios; A multi-physics monitoring unit is used to monitor the performance parameters of the flexible DC power transmission module during the test process; the performance parameters include electromagnetic field strength, signal transmission integrity, module temperature rise and mechanical vibration; the performance parameters are used to evaluate the comprehensive performance of the flexible DC power transmission module under multiple stresses.

2. The multi-dimensional electromagnetic compatibility test system for flexible DC power transmission modules according to claim 1, characterized in that, The dynamic power grid simulation unit includes an IGBT fault generator, an FPGA harmonic controller, a nonlinear load module, and a bipolar redundancy switching device, wherein: The IGBT fault generator is connected to the bipolar redundancy switching device. The IGBT fault generator is connected to the FPGA harmonic controller; The FPGA harmonic controller is connected to the nonlinear load module; The IGBT fault generator and the bipolar redundancy switching device are respectively connected to the IGBT module of the flexible DC power transmission module. The FPGA harmonic controller is connected to a digital simulation platform; The digital simulation platform is used to transmit fault waveform parameters and harmonic control parameters to the FPGA harmonic controller. The FPGA harmonic controller is used to output a drive signal to the IGBT fault generator according to the fault waveform parameters to control the IGBT module of the flexible DC power transmission module to switch to short-circuit state; and to send preset harmonic components to the nonlinear load module according to the harmonic control parameters to simulate the resonant overvoltage condition of new energy grid connection. The bipolar redundancy switching device is used to form a fault response control loop with the IGBT module of the flexible DC power transmission module after the IGBT module switches to a short-circuit state, so that the IGBT module of the flexible DC power transmission module switches to a unipolar operation mode.

3. The multi-dimensional electromagnetic compatibility test system for flexible DC power transmission modules according to claim 2, characterized in that, The IGBT fault generator adopts a three-level topology; the nonlinear load module simulates the resonant overvoltage condition of new energy grid connection by integrating an RLC resonant circuit and a switching matrix.

4. The multi-dimensional electromagnetic compatibility test system for flexible DC power transmission modules according to claim 1, characterized in that, The broadband interference injection unit includes a pulse group simulator, a π-type coupling network, a log-periodic antenna array, and an impedance matching circuit. The pulse group simulator is connected to the π-type coupling network; The π-type coupling network is connected to the power port of the flexible DC transmission power module; The log-periodic antenna array constructs a spatial radiation field; The π-type coupling network and the impedance matching circuit are respectively connected to the spatial radiation field; The pulse group simulator is used to transmit the generated predefined waveform to the π-type coupled network; The π-type coupling network is used to couple a predefined waveform to the power port of the flexible DC transmission power module; The impedance matching circuit monitors the reflection coefficient of the space radiation field in real time and performs dynamic parameter calibration on the reflection coefficient, feeding back the calibrated reflection coefficient to the space radiation field.

5. The multi-dimensional electromagnetic compatibility test system for flexible DC transmission power modules according to claim 4, characterized in that, The pulse group simulator adopts an avalanche transistor series structure; the π-type coupling network adopts an LCR composite structure; and the impedance matching circuit includes a variable inductor and an RF transformer.

6. The multi-dimensional electromagnetic compatibility test system for flexible DC power transmission modules according to claim 1, characterized in that, The multiphysics monitoring unit includes an electromagnetic probe array, an FBG fiber optic sensor, a MEMS vibration sensor, and a mixed signal analyzer; the electromagnetic probe array, the FBG fiber optic sensor, and the MEMS vibration sensor are respectively connected to the mixed signal analyzer; The electromagnetic probe array is used to collect electromagnetic radiation data; The FBG fiber optic sensor is used to collect temperature field data; The MEMS vibration sensor is used to monitor mechanical vibration data; The mixed signal analyzer is used to obtain the electromagnetic field strength based on electromagnetic radiation data and to obtain the module temperature rise based on temperature field data.

7. The multi-dimensional electromagnetic compatibility test system for flexible DC power transmission modules according to claim 6, characterized in that, The electromagnetic probe array is connected to the mixed signal analyzer via a signal conditioning module; the FBG fiber optic sensor is connected to the mixed signal analyzer via a wavelength division multiplexer.

8. The multi-dimensional electromagnetic compatibility test system for flexible DC transmission power modules according to claim 6, characterized in that, The mixed signal analyzer is connected to an edge computing node, which is used to reconstruct a three-dimensional field distribution model based on electromagnetic field strength, module temperature rise, and mechanical vibration. The reconstructed three-dimensional field distribution model is then compared with a pre-built digital twin model to obtain an evaluation result.

9. The multi-dimensional electromagnetic compatibility test system for flexible DC transmission power modules according to claim 6, characterized in that, The electromagnetic probe array includes a near-field magnetic field probe and an electric field probe.

10. A multi-dimensional electromagnetic compatibility (EMC) test method for a flexible DC power transmission module, based on the multi-dimensional EMC test system for the flexible DC power transmission module according to any one of claims 1-9, characterized in that, include: A dynamic power grid simulation unit is used to simulate the combined interference scenarios of power grid faults and disturbances, so that the flexible DC transmission power module can be made to exhibit the working state in a complex power grid environment. A wideband interference injection unit is used to simulate the noise during the switching process of IGBT / IGCT in a flexible DC power transmission module, in order to simulate various electromagnetic interference scenarios; A multi-physics monitoring unit was used to monitor the performance parameters of the flexible DC power transmission module during the test. The performance parameters included electromagnetic field strength, signal transmission integrity, module temperature rise, and mechanical vibration. These performance parameters were used to evaluate the comprehensive performance of the flexible DC power transmission module under multiple stresses.

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