A current measuring device and method for a press-pack IGBT internal multi-chip

Abstract

The application discloses a kind of current measuring device and method for the internal multi-chip of crimping type IGBT, comprising: signal processing unit and the sensing unit of the corresponding current guide column periphery of each IGBT chip;Wherein, each sensing unit is used to obtain the low-frequency current component and high-frequency current component of the magnetic field generated by the corresponding IGBT chip current;The signal processing unit is used to decouple signal based on all low-frequency current component and high-frequency current component, to obtain the current value of each IGBT chip.The application realizes the independent, synchronous and high-precision detection of multi-chip current in limited installation space by multiple sensing units, effectively reduces the influence of adjacent chip magnetic field crosstalk and external electromagnetic interference on measurement results, solves the problem that single sensor cannot measure direct current, low-frequency and high-frequency current, and meets the chip-level current high-precision detection demand of crimping type IGBT module under full working condition.

Description

Technical Field

[0001] This invention relates to the field of high-power semiconductor device testing and condition monitoring technology, and more specifically, to a current measurement device and method for multiple chips inside a press-fit IGBT. Background Technology

[0002] Press-fit IGBT modules are widely used in high-voltage direct current transmission, flexible AC transmission, and high-power converters due to their high reliability and large current capacity. To achieve high current ratings, multiple IGBT chips are typically connected in parallel within the module. However, due to the dispersion of chip parameters and parasitic parameter differences caused by packaging layout, dynamic and static current imbalances exist among the parallel chips, which can easily lead to localized overheating failures and seriously threaten module reliability. Therefore, real-time and accurate monitoring of the current of each chip within the module is a core prerequisite for achieving chip-level current sharing, protection, and health management.

[0003] Some research has been conducted on methods that integrate hybrid current sensors (such as PCB Rogowski coils combined with Hall effect sensing units) into press-fit IGBT modules to measure chip current. However, such methods typically face two major challenges: Current skin effect and magnetic field crosstalk: The target chip has a high current frequency, resulting in a skin effect that causes the generated magnetic field to change with frequency, making the placement of the Hall sensor unit highly sensitive to this. Furthermore, the internal space of the press-fit module is extremely compact. When current sensors need to be placed for multiple closely arranged parallel IGBT chips within a limited area, the currents of adjacent chips will generate magnetic fields on the sensors. This causes the sensor's output signal to be a mixed signal related to the currents of all adjacent chips, rather than a signal related only to the current of the target chip, resulting in a significant decrease in measurement accuracy.

[0004] Sensor's inherent anti-interference capability: The transient switching within the module generates extremely high di / dt and du / dt values, creating complex near-field electromagnetic interference. If the sensor does not have a high anti-interference design, its output signal will be severely contaminated by this high-frequency noise.

[0005] Existing solutions often focus on optimizing the performance of individual sensors, such as increasing bandwidth, adding shielding, or reducing crosstalk by increasing sensor spacing. However, these methods are often impractical within space-constrained press-fit modules. Furthermore, there is a lack of effective system-level layout optimization and signal processing techniques to address the crosstalk issue caused by adjacent chip currents.

[0006] For example, in existing technologies, due to the extremely compact internal space of press-fit modules, when current sensors need to be arranged for multiple closely spaced parallel IGBT chips within a limited area, the adjacent currents will cause crosstalk to the magnetic field sensors. This results in the magnetic field measured by the sensors being generated not only by the target chip current but also by the adjacent currents, severely affecting measurement accuracy. Furthermore, the switching transients within press-fit IGBT modules generate extremely high di / dt and du / dt values, forming complex near-field electromagnetic interference. Measures need to be taken to suppress this interference and prevent high-frequency noise from affecting the measurement results. Summary of the Invention

[0007] This invention proposes a current measurement device and method for multiple chips inside a press-fit IGBT, in order to solve the problem of how to measure the current of multiple chips inside a press-fit IGBT with high precision and synchronously.

[0008] To address the aforementioned problems, according to one aspect of the present invention, a current measurement device for multiple chips within a press-fit IGBT is provided. The device includes: a signal processing unit and a sensing unit disposed around the periphery of a current-conducting post corresponding to each IGBT chip; wherein... Each sensing unit is used to acquire the low-frequency current component and high-frequency current component of the magnetic field generated by the corresponding IGBT chip current. The signal processing unit is used to decouple the signal based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip.

[0009] Preferably, each sensing unit adopts a multi-layer PCB structure, and each sensing unit includes: a magnetoresistive sensor and a PCB Rogowski coil; wherein, The magnetoresistive sensor is surface-mounted on the top layer of the PCB board and is used to measure the low-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip. The PCB Rogowski coil is nested on the current-conducting post of the corresponding IGBT chip and is used to measure the high-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip.

[0010] Preferably, the PCB Rogowski coil adopts a three-layer PCB winding structure. The upper layer winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer winding adopts a direct connection winding method, and a return line is wound in the middle layer, which is opposite to the direction of the herringbone winding in the upper layer.

[0011] Preferably, the PCB Rogowski coil further includes an electric field shielding layer disposed on both sides of the three-layer PCB winding structure.

[0012] Preferably, in the two-dimensional planar layout, the position of each magnetoresistive sensor is set according to the principle of maximizing the distance between it and the adjacent IGBT chip, and a magnetic shielding layer is provided between each adjacent IGBT chip and the corresponding magnetoresistive sensor forming the IGBI module. For symmetrical parallel IGBT chipsets, multiple magnetoresistive sensors are arranged in a centrally symmetrical or axisymmetric manner.

[0013] Preferably, the signal processing unit includes: a signal amplification circuit, a passive-active integrator circuit, a low-pass filter, a high-pass filter, an adder, and a signal processing module; wherein, The signal amplification circuit is used to amplify the low-frequency current component output by each magnetoresistive sensor. The low-pass filter is used to perform low-pass filtering on the amplified low-frequency current component. The passive-active integrator circuit is used to integrate the high-frequency current component output by each PCB Rogowski coil. The high-pass filter is used to perform high-pass filtering on the high-frequency current component after integration. The adder is used to combine the filtered low-frequency current component and the high-frequency current component to obtain the measured voltage signal. The signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip.

[0014] Preferably, the signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip, including: , in, For the first Current per IGBT chip; For the first The measured voltage signal corresponding to each sensing unit; Representing the The first sensing unit for the first The sensitivity of the current of an IGBT chip.

[0015] Preferably, the device comprises: A controllable current source is used to sequentially inject known test currents into individual IGBT chips. Simultaneously record the output of all sensing units. Based on Obtain each element in the coupling matrix M.

[0016] According to another aspect of the present invention, a current measurement method is provided based on the current measurement device for multiple chips inside a press-fit IGBT according to any one of claims 1-8, the method comprising: The low-frequency and high-frequency current components of the magnetic field generated by the corresponding IGBT chip current are obtained using the sensing unit. The signal processing unit decouples the signals based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip.

[0017] Preferably, each sensing unit adopts a multi-layer PCB structure, and each sensing unit includes: a magnetoresistive sensor and a PCB Rogowski coil; wherein, The magnetoresistive sensor is surface-mounted on the top layer of the PCB board and is used to measure the low-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip. The PCB Rogowski coil is nested on the current-conducting post of the corresponding IGBT chip and is used to measure the high-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip.

[0018] Preferably, the PCB Rogowski coil adopts a three-layer PCB winding structure. The upper layer winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer winding adopts a direct connection winding method, and a return line is wound in the middle layer, which is opposite to the direction of the herringbone winding in the upper layer.

[0019] Preferably, the PCB Rogowski coil further includes an electric field shielding layer disposed on both sides of the three-layer PCB winding structure.

[0020] Preferably, the method further includes: In the two-dimensional planar layout, the position of each magnetoresistive sensor is set according to the principle of maximizing the distance between it and the adjacent IGBT chip, and a magnetic shielding layer is set between each adjacent IGBT chip and the corresponding magnetoresistive sensor forming the IGBI module. For symmetrical parallel IGBT chipsets, multiple magnetoresistive sensors are arranged in a centrally symmetrical or axisymmetric manner.

[0021] Preferably, the signal processing unit performs signal decoupling based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip, including: The low-frequency current component output by each magnetoresistive sensor is amplified using a signal amplification circuit. The amplified low-frequency current component is subjected to low-pass filtering using a low-pass filter. The high-frequency current component output by each PCB Rogowski coil is integrated using a passive-active integrator circuit. The high-frequency current component after integration is subjected to high-pass filtering using a high-pass filter. An adder is used to combine the filtered low-frequency current component and the high-frequency current component to obtain the measured voltage signal. The measured voltage signal is decoupled using a signal processing module to obtain the current value of each IGBT chip.

[0022] Preferably, the signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip, including: , in, For the first Current per IGBT chip; For the first The measured voltage signal corresponding to each sensing unit; Representing the The first sensing unit for the first The sensitivity of the current of an IGBT chip.

[0023] Preferably, the method further includes: A known test current is injected sequentially into a single IGBT chip using a controllable current source. Simultaneously record the output of all sensing units. Based on Obtain each element in the coupling matrix M.

[0024] This invention provides a current measurement device and method for multiple chips inside a press-fit IGBT. Through multiple sensing units, it achieves independent, synchronous, and high-precision detection of the current of multiple chips within a limited installation space, and effectively reduces the influence of magnetic field crosstalk between adjacent chips and external electromagnetic interference on the measurement results. It solves the problem that a single sensor cannot simultaneously measure DC, low-frequency, and high-frequency currents, and meets the high-precision chip-level current detection requirements of press-fit IGBT modules under all operating conditions. Attached Figure Description

[0025] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a schematic diagram of the current measuring device 100 for multiple chips inside a press-fit IGBT according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the layering of sensing units according to an embodiment of the present invention; Figure 3 (a) and (b) are respectively a top view and a bottom view of a PCB Rogowski coil winding according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sensor layout structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the working principle of a current measuring device according to an embodiment of the present invention. Figure 6 This is a flowchart of a current measurement method 600 for multiple chips inside a press-fit IGBT according to an embodiment of the present invention. Detailed Implementation

[0026] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0027] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0028] Figure 1 This is a schematic diagram of the structure of a current measurement device 100 for multiple chips inside a press-fit IGBT according to an embodiment of the present invention. Figure 1 As shown, the current measurement device for multiple chips inside a press-fit IGBT provided by this embodiment of the invention achieves independent, synchronous, and high-precision detection of the current of multiple chips within a limited installation space through multiple sensing units. It effectively reduces the influence of magnetic field crosstalk between adjacent chips and external electromagnetic interference on the measurement results, solving the problem that a single sensor cannot simultaneously measure DC, low-frequency, and high-frequency currents, thus meeting the high-precision chip-level current detection requirements of press-fit IGBT modules under all operating conditions. The current measurement device 100 for multiple chips inside a press-fit IGBT provided by this embodiment of the invention includes: a signal processing unit 101 and a sensing unit 102 disposed around the current-conducting post corresponding to each IGBT chip.

[0029] Preferably, each sensing unit 102 is used to acquire the low-frequency current component and the high-frequency current component of the magnetic field generated by the corresponding IGBT chip current.

[0030] Preferably, each sensing unit adopts a multi-layer PCB structure, and each sensing unit includes: a magnetoresistive sensor and a PCB Rogowski coil; wherein, The magnetoresistive sensor is surface-mounted on the top layer of the PCB board and is used to measure the low-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip. The PCB Rogowski coil is nested on the current-conducting post of the corresponding IGBT chip and is used to measure the high-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip.

[0031] Preferably, the PCB Rogowski coil adopts a three-layer PCB winding structure. The upper layer winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer winding adopts a direct connection winding method, and a return line is wound in the middle layer, which is opposite to the direction of the herringbone winding in the upper layer.

[0032] Preferably, the PCB Rogowski coil further includes an electric field shielding layer disposed on both sides of the three-layer PCB winding structure.

[0033] Preferably, in the two-dimensional planar layout, the position of each magnetoresistive sensor is set according to the principle of maximizing the distance between it and the adjacent IGBT chip, and a magnetic shielding layer is provided between each adjacent IGBT chip and the corresponding magnetoresistive sensor forming the IGBI module. For symmetrical parallel IGBT chipsets, multiple magnetoresistive sensors are arranged in a centrally symmetrical or axisymmetric manner.

[0034] In this invention, each sensing unit is used for current measurement of an IGBT chip. It adopts a multi-layer PCB structure and integrates a magnetoresistive sensor and a PCB Rogowski coil.

[0035] Combination Figure 2 As shown, the magnetoresistive sensor, employing either tunneling magnetoresistive (TMR) or anisotropic magnetoresistive (AMR) sensors, is surface-mounted on the top layer of the PCB board and used to measure low-frequency current components. Its mounting location was determined through finite element method simulation of the magnetic field, selecting a position around the current-carrying pillars of the target chip that is sensitive to the target chip's current, while ensuring that the magnetic field at this location is minimally affected by the skin effect of the target current. This location ensures that the transfer function of the sensor output to the target chip current remains stable over a wide frequency band, rather than changing significantly with frequency variations.

[0036] A PCB Rogowski coil is a Rogowski coil manufactured using a multilayer PCB process. It is nested on the current-carrying pillars of the target chip and is used to measure high-frequency current components.

[0037] The structure of the PCB Rogowski coil includes: Herringbone and loop winding structure: The upper layer of winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer of winding adopts a direct connection winding method, while a loop is wound in the middle layer. This loop runs in the opposite direction to the herringbone winding of the upper layer. The three layers of PCB winding together form the Rogowski coil of this invention. This structure can effectively counteract the external uniform alternating magnetic field that passes perpendicularly through the coil plane, significantly improving the anti-electromagnetic interference capability. The top and bottom views of the PCB Rogowski coil winding are shown below. Figure 3 As shown in (a) and (b).

[0038] In addition, such as Figure 2 As shown, grounded copper layers are provided on both the upper and lower sides of the coil to isolate interference generated by the high du / dt switching noise of the power device through capacitive coupling.

[0039] In this invention, to address the magnetic field crosstalk problem caused by the dense arrangement of multiple sensing units inside a press-fit IGBT module, the sensors are arranged according to the following layout principles: Maximizing distance and utilizing shielding. Specifically, in the two-dimensional planar layout, the distance between each magnetoresistive sensor (especially its core sensing area) and the adjacent IGBT sub-modules is maximized. At the same time, a thin magnetic shielding layer is installed between each IGBT sub-module as a physical barrier to attenuate stray magnetic fields leaking from a neighboring IGBT sub-module to the target chip magnetoresistive sensor.

[0040] Symmetrical layout. Specifically, for symmetrically parallel chipsets, a centrally symmetrical or axisymmetric sensor layout is adopted. Layout methods are as follows: Figure 4 As shown, this layout can make the coupling relationship between the channels present a certain regularity (such as the coupling coefficient matrix having symmetry), simplifying the establishment and solution of the subsequent decoupling model.

[0041] Preferably, the signal processing unit 101 is used to decouple the signal based on all low-frequency current components and high-frequency current components to obtain the current value of each IGBT chip.

[0042] Preferably, the signal processing unit includes: a signal amplification circuit, a passive-active integrator circuit, a low-pass filter, a high-pass filter, an adder, and a signal processing module; wherein, The signal amplification circuit is used to amplify the low-frequency current component output by each magnetoresistive sensor. The low-pass filter is used to perform low-pass filtering on the amplified low-frequency current component. The passive-active integrator circuit is used to integrate the high-frequency current component output by each PCB Rogowski coil. The high-pass filter is used to perform high-pass filtering on the high-frequency current component after integration. The adder is used to combine the filtered low-frequency current component and the high-frequency current component to obtain the measured voltage signal. The signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip.

[0043] Preferably, the signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip, including: , in, For the first Current per IGBT chip; For the first The measured voltage signal corresponding to each sensing unit; Representing the The first sensing unit for the first The sensitivity of the current of an IGBT chip.

[0044] Preferably, the device comprises: A controllable current source is used to sequentially inject known test currents into individual IGBT chips. Simultaneously record the output of all sensing units. Based on Obtain each element in the coupling matrix M.

[0045] Due to physical space constraints, adjacent current crosstalk is unavoidable. To prevent adjacent current crosstalk from affecting the accurate measurement of a single sensing unit, this invention proposes a signal post-processing decoupling algorithm to achieve current measurement.

[0046] Combination Figure 5 As shown, in this invention, a passive-active combined integrator is used to process the output signal of the PCB Rogowski coil. This integrator cascades an active integrator circuit after the passive integrator stage. By appropriately setting the RC time constant for matching, it can extend the low-frequency bandwidth while avoiding the saturation and drift problems caused by excessive gain near DC in traditional active integrators. A damping resistor is connected in parallel at the integrator front end or the PCB Rogowski coil output terminal to optimize the frequency response of the sensor system, suppress resonance peaks, and ensure a flat amplitude-frequency characteristic within the target frequency band.

[0047] The output of the magnetoresistive sensor is connected to the signal amplification circuit via a lead wire. Then, the low-frequency current component of the measured current is output through a low-pass filter. Finally, the two output signals are combined by an adder to achieve wideband measurement of the target current.

[0048] In this invention, to decouple the signals, a coupling matrix needs to be established first. Specifically, through experimental calibration or high-precision finite element electromagnetic simulation, a linear coupling model is established from the "actual current of each chip" to the "output signal of each sensing unit". For a system with n chips and n sensing units, the relationship can be expressed as: , in, For the first The measured voltage signal corresponding to each sensing unit; For the first The target chip current; Representing the The first sensing unit for the first The sensitivity of the chip current is represented by the main diagonal elements, which represent the sensitivity coefficient of the sensing unit on the target chip to the target current, and the remaining elements represent the crosstalk coefficient of the adjacent current to the sensor.

[0049] Then, signal decoupling is performed in the signal processing unit. Specifically, in the signal processing unit (such as an FPGA or a high-performance MCU), the acquired multi-sensor unit output signals are processed. Perform real-time decoupling operations. This is done by multiplying by the coupling matrix. The inverse matrix of the given matrix can be used to separate the independent current values ​​of each chip from the mixed signal: , Wherein, coupling matrix It can be pre-configured in the system. For specific batches of modules, it can be obtained by a one-time calibration at a specific operating point (such as DC or low-frequency testing at rated current) to compensate for differences caused by manufacturing tolerances.

[0050] Specifically, in this invention, the steps for implementing chip current measurement include: 1. Based on the chip layout of the target press-fit IGBT module, electromagnetic field simulation is performed to determine the optimal installation position of each magnetoresistive sensor (a position where the magnetic field distribution is not sensitive to frequency) and to preliminarily assess the coupling situation. Subsequently, the overall sensor layout is designed according to the optimization layout principles (maximizing spacing, utilizing shielding, and considering symmetry).

[0051] 2. When manufacturing the sensing unit, design the PCB according to the principle of optimized layout, mount the miniature TMR / AMR sensor in the predetermined position, and fix the PCB sensing unit around the corresponding flow guide column inside the module with insulating pads.

[0052] 3. After completing module assembly, the coupling matrix of the integrated sensing system is... Calibration can be performed. A precise, controllable current source can be used to sequentially inject known test currents into each chip. Simultaneously record the outputs of all n sensing units. Through n such independent tests, it is possible to calculate... Obtain each element of the coupling matrix. Write this matrix into the decoupling algorithm of the signal processing unit.

[0053] 4. During operation, the system acquires signals from various sensors in real time, and after conditioning and ADC sampling, calls the stored inverse matrix. Perform matrix multiplication operations and output the decoupled chip current value I in real time for chip current sharing control, overcurrent protection or health status monitoring.

[0054] The present invention provides a current measurement device for multiple chips inside a press-fit IGBT. It combines a Rogowski coil and a magnetoresistive sensor through a multi-layer PCB structure and combines their output signals through a signal synthesis circuit to achieve wideband measurement of chip current from DC to tens of MHz. Through an optimized sensor arrangement structure and a corresponding current signal decoupling method, it achieves high-precision, independent, and synchronous measurement of the current of multiple parallel chips in an extremely compact space, and effectively suppresses magnetic field crosstalk between sensors and external electromagnetic interference.

[0055] This invention effectively solves the technical pain points of traditional commercial current sensors in chip-level current detection of press-fit IGBT modules, such as low integration, weak anti-interference capability, and incomplete bandwidth coverage, achieving significant technical results. Addressing the compact structure of multiple parallel chips within the module, a multi-layer PCB vertical stack-integration design integrates the magnetoresistive sensor and PCB Rogowski coil around the emitter current guide post of a single IGBT chip, achieving non-invasive and accurate measurement of the single-chip current. This adapts to the limited installation space within the module, significantly improving integration. Simultaneously, by integrating an electromagnetic shielding layer and a Rogowski coil return winding layer, the device's resistance to external electromagnetic interference is significantly enhanced, reducing detection errors. Furthermore, the designed dual-channel conditioning and signal synthesis circuit, combined with the HOKA principle, achieves linear superposition of the magnetoresistive sensor and Rogowski coil signals, accurately matching the parameters of the two channels. This results in a flat amplitude-frequency response and linear phase across the entire frequency band from DC to tens of MHz, effectively restoring the full-bandwidth current waveform. This solves the problem that a single sensor cannot simultaneously measure DC, low-frequency, and high-frequency current, meeting the high-precision chip-level current detection requirements of press-fit IGBT modules under all operating conditions.

[0056] The current measurement device for multiple chips inside a press-fit IGBT provided by this invention is suitable for high-voltage, high-current, and high-reliability power electronic equipment using press-fit insulated gate bipolar transistor power modules. It is especially suitable for online monitoring and accurate evaluation of the current distribution status, transient uneven flow behavior, and device health status of parallel chips inside the module.

[0057] The following specific examples illustrate the embodiments of the present invention. In an embodiment of the present invention, a press-fit IGBT power module is taken as an example. The module contains four IGBT chips arranged in parallel, each chip corresponding to a current sensing unit. Since the four chips have different parasitic parameters during conduction and switching, dynamic and static current imbalances are easily generated. Therefore, it is necessary to measure the current of the four chips independently and synchronously.

[0058] In this embodiment, a highly interference-resistant integrated current sensing unit is set around the current-conducting pillar corresponding to each IGBT chip, with four sensing units corresponding one-to-one with the four chips. Each sensing unit adopts a multi-layer PCB structure with a through-hole in the center for the current-conducting pillar to pass through. A magnetoresistive sensor is mounted on the top layer of the sensing unit to detect the low-frequency current component of the magnetic field generated by the target chip current; a Rogowski coil is integrated inside the PCB to detect the high-frequency current component generated by the change in the target chip current. Grounding shielding layers are set above and below the coil layer to reduce electric field interference caused by high du / dt during module switching; at the same time, a return wire is set in the coil structure to suppress the coupling interference of the external alternating magnetic field perpendicular to the PCB plane.

[0059] In terms of sensor layout, using finite element electromagnetic field simulation, each magnetoresistive sensor is preferentially placed around its corresponding current-carrying pillar in a position most sensitive to the target chip current and where the magnetic field changes less with frequency (less affected by the skin effect). Simultaneously, a thin magnetic shielding layer is placed between adjacent chip sub-modules to reduce magnetic field crosstalk between adjacent chip currents and the target sensor. For symmetrically arranged chip structures, the four sensing units are arranged symmetrically to ensure a regular coupling relationship between the measurement channels, facilitating the subsequent establishment of a decoupling model.

[0060] In signal processing, the output terminal of the PCB Rogowski coil is connected to the passive-active combined integrator circuit via leads, and then the high-frequency current component of the measured current is output after passing through a high-pass filter; the output terminal of the magnetoresistive sensor is connected to the signal amplification circuit via leads, and then the low-frequency current component of the measured current is output after passing through a low-pass filter; finally, the two output signals are combined by an adder to achieve wideband measurement of the target current.

[0061] After the module assembly is completed, the sensing system is calibrated. During calibration, a known test current is applied sequentially and individually to the corresponding branches of the four chips, and the output signals of the four sensing units are simultaneously acquired, thereby establishing a 4×4 coupling matrix between the "actual chip current" and the "sensor unit output signal". This coupling matrix is ​​then inverted, and the inverse matrix is ​​pre-written into the signal processing unit. The signal processing unit can be implemented using a field-programmable gate array (FPGA), a digital signal processor (DSP), or a microcontroller.

[0062] In actual operation, the press-fit IGBT module runs in the converter circuit. When the module is turned on or off, each sensing unit synchronously acquires the current magnetic field signal at the corresponding location. The magnetoresistive sensor output reflects the low-frequency and quasi-static information of the chip current, while the Rogowski coil output reflects the high-frequency dynamic changes of the chip current. The signal conditioning circuit integrates the Rogowski coil output and amplifies and filters the magnetoresistive sensor output. The adder combines the high-frequency and low-frequency components, and the system then sends the combined signal outputs to the decoupling algorithm module. By calling a pre-stored inverse matrix for real-time matrix operations, the independent current values ​​of the four chips are separated from the mixed signal.

[0063] Using the above method, the current distribution of the four parallel IGBT chips during the steady-state conduction phase and the dynamic current change characteristics during the turn-on and turn-off processes can be obtained in real time. If a chip exhibits continuous bias current, excessive transient overshoot, or current changes that are significantly inconsistent with the other chips, it can be determined that the chip has problems such as inconsistent drive, abnormal crimping status, or local parameter degradation, and current sharing control, fault warning, or protection actions can be executed accordingly.

[0064] This embodiment demonstrates that the present invention can be directly applied to the current measurement of multiple parallel chips inside a press-fit IGBT module, achieving independent, synchronous, and high-precision detection of the current of multiple chips within a limited installation space, and effectively reducing the influence of magnetic field crosstalk between adjacent chips and external electromagnetic interference on the measurement results.

[0065] Figure 6 This is a flowchart of a current measurement method 600 for multiple chips inside a press-fit IGBT according to an embodiment of the present invention. Figure 6 As shown, the current measurement method 600 based on the current measurement device for multiple chips inside a press-fit IGBT provided by the present invention includes: Step 601: Use the sensing unit to obtain the low-frequency current component and high-frequency current component of the magnetic field generated by the corresponding IGBT chip current. Step 602: The signal processing unit performs signal decoupling based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip.

[0066] Preferably, each sensing unit adopts a multi-layer PCB structure, and each sensing unit includes: a magnetoresistive sensor and a PCB Rogowski coil; wherein, The magnetoresistive sensor is surface-mounted on the top layer of the PCB board and is used to measure the low-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip. The PCB Rogowski coil is nested on the current-conducting post of the corresponding IGBT chip and is used to measure the high-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip.

[0067] Preferably, the PCB Rogowski coil adopts a three-layer PCB winding structure. The upper layer winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer winding adopts a direct connection winding method, and a return line is wound in the middle layer, which is opposite to the direction of the herringbone winding in the upper layer.

[0068] Preferably, the PCB Rogowski coil further includes an electric field shielding layer disposed on both sides of the three-layer PCB winding structure.

[0069] Preferably, the method further includes: In the two-dimensional planar layout, the position of each magnetoresistive sensor is set according to the principle of maximizing the distance between it and the adjacent IGBT chip, and a magnetic shielding layer is set between each adjacent IGBT chip and the corresponding magnetoresistive sensor forming the IGBI module. For symmetrical parallel IGBT chipsets, multiple magnetoresistive sensors are arranged in a centrally symmetrical or axisymmetric manner.

[0070] Preferably, the signal processing unit performs signal decoupling based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip, including: The low-frequency current component output by each magnetoresistive sensor is amplified using a signal amplification circuit. The amplified low-frequency current component is subjected to low-pass filtering using a low-pass filter. The high-frequency current component output by each PCB Rogowski coil is integrated using a passive-active integrator circuit. The high-frequency current component after integration is subjected to high-pass filtering using a high-pass filter. An adder is used to combine the filtered low-frequency current component and the high-frequency current component to obtain the measured voltage signal. The measured voltage signal is decoupled using a signal processing module to obtain the current value of each IGBT chip.

[0071] Preferably, the signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip, including: , in, For the first Current per IGBT chip; For the first The measured voltage signal corresponding to each sensing unit; Representing the The first sensing unit for the first The sensitivity of the current of an IGBT chip.

[0072] Preferably, the method further includes: A known test current is injected sequentially into a single IGBT chip using a controllable current source. Simultaneously record the output of all sensing units. Based on Obtain each element in the coupling matrix M.

[0073] The current measurement method 600 for multiple chips inside a press-fit IGBT according to an embodiment of the present invention corresponds to the current measurement device 100 for multiple chips inside a press-fit IGBT according to another embodiment of the present invention, and will not be described again here.

[0074] The present invention has been described with reference to a few embodiments. However, it will be apparent to those skilled in the art that other embodiments besides those disclosed above fall equivalently within the scope of the present invention.

[0075] Generally, all terms used in this invention are interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless explicitly stated otherwise.

[0076] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0078] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0079] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0080] 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 protection scope of the present invention.

Claims

1. A current measurement device for multiple chips inside a press-fit IGBT, characterized in that, The device includes: a signal processing unit and a sensing unit disposed around the current-carrying pillar corresponding to each IGBT chip; wherein... Each sensing unit is used to acquire the low-frequency current component and high-frequency current component of the magnetic field generated by the corresponding IGBT chip current. The signal processing unit is used to decouple the signal based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip.

2. The apparatus according to claim 1, characterized in that, Each sensing unit employs a multi-layer PCB structure, and each sensing unit includes: a magnetoresistive sensor and a PCB Rogowski coil; wherein... The magnetoresistive sensor is surface-mounted on the top layer of the PCB board and is used to measure the low-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip. The PCB Rogowski coil is nested on the current-conducting post of the corresponding IGBT chip and is used to measure the high-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip.

3. The apparatus according to claim 2, characterized in that, The PCB Rogowski coil adopts a three-layer PCB winding structure. The upper layer winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer winding adopts a direct connection winding method, and a return line is wound in the middle layer, which is opposite to the direction of the herringbone winding in the upper layer.

4. The apparatus according to claim 3, characterized in that, The PCB Rogowski coil further includes an electric field shielding layer disposed on both sides of the three-layer PCB winding structure.

5. The apparatus according to claim 2, characterized in that, In the two-dimensional planar layout, the position of each magnetoresistive sensor is set according to the principle of maximizing the distance between it and the adjacent IGBT chip, and a magnetic shielding layer is set between each adjacent IGBT chip and the corresponding magnetoresistive sensor forming the IGBI module. For symmetrical parallel IGBT chipsets, multiple magnetoresistive sensors are arranged in a centrally symmetrical or axisymmetric manner.

6. The apparatus according to claim 2, characterized in that, The signal processing unit includes: a signal amplification circuit, a passive-active integrator circuit, a low-pass filter, a high-pass filter, an adder, and a signal processing module; wherein, The signal amplification circuit is used to amplify the low-frequency current component output by each magnetoresistive sensor. The low-pass filter is used to perform low-pass filtering on the amplified low-frequency current component. The passive-active integrator circuit is used to integrate the high-frequency current component output by each PCB Rogowski coil. The high-pass filter is used to perform high-pass filtering on the high-frequency current component after integration. The adder is used to combine the filtered low-frequency current component and the high-frequency current component to obtain the measured voltage signal. The signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip.

7. The apparatus according to claim 6, characterized in that, The signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip, including: ， in, For the first Current per IGBT chip; For the first The measured voltage signal corresponding to each sensing unit; Representing the The first sensing unit for the first The sensitivity of the current of an IGBT chip.

8. The apparatus according to claim 7, characterized in that, The device includes: A controllable current source is used to sequentially inject known test currents into individual IGBT chips. Simultaneously record the output of all sensing units. Based on Obtain each element in the coupling matrix M.

9. A current measurement method based on the current measurement device for multiple chips inside a press-fit IGBT according to any one of claims 1-8, characterized in that, The method includes: The low-frequency and high-frequency current components of the magnetic field generated by the corresponding IGBT chip current are obtained using the sensing unit. The signal processing unit decouples the signals based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip.

10. The method according to claim 9, characterized in that, Each sensing unit employs a multi-layer PCB structure, and each sensing unit includes: a magnetoresistive sensor and a PCB Rogowski coil; wherein... The magnetoresistive sensor is surface-mounted on the top layer of the PCB board and is used to measure the low-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip. The PCB Rogowski coil is nested on the current-conducting post of the corresponding IGBT chip and is used to measure the high-frequency current component of the magnetic field generated by the current of the corresponding IGBT chip.

11. The method according to claim 10, characterized in that, The PCB Rogowski coil adopts a three-layer PCB winding structure. The upper layer winding adopts a herringbone winding method, with the center of the herringbone winding running around the guide post. The lower layer winding adopts a direct connection winding method, and a return line is wound in the middle layer, which is opposite to the direction of the herringbone winding in the upper layer.

12. The method according to claim 10, characterized in that, The PCB Rogowski coil further includes an electric field shielding layer disposed on both sides of the three-layer PCB winding structure.

13. The method according to claim 10, characterized in that, The method further includes: In the two-dimensional planar layout, the position of each magnetoresistive sensor is set according to the principle of maximizing the distance between it and the adjacent IGBT chip, and a magnetic shielding layer is set between each adjacent IGBT chip and the corresponding magnetoresistive sensor forming the IGBI module. For symmetrical parallel IGBT chipsets, multiple magnetoresistive sensors are arranged in a centrally symmetrical or axisymmetric manner.

14. The method according to claim 10, characterized in that, The signal processing unit performs signal decoupling based on all low-frequency and high-frequency current components to obtain the current value of each IGBT chip, including: The low-frequency current component output by each magnetoresistive sensor is amplified using a signal amplification circuit. The amplified low-frequency current component is subjected to low-pass filtering using a low-pass filter. The high-frequency current component output by each PCB Rogowski coil is integrated using a passive-active integrator circuit. The high-frequency current component after integration is subjected to high-pass filtering using a high-pass filter. An adder is used to combine the filtered low-frequency current component and the high-frequency current component to obtain the measured voltage signal. The measured voltage signal is decoupled using a signal processing module to obtain the current value of each IGBT chip.

15. The method according to claim 14, characterized in that, The signal processing module is used to decouple the measured voltage signal to obtain the current value of each IGBT chip, including: ， in, For the first Current per IGBT chip; For the first The measured voltage signal corresponding to each sensing unit; Representing the The first sensing unit for the first The sensitivity of the current of an IGBT chip.

16. The method according to claim 15, characterized in that, The method further includes: A known test current is injected sequentially into a single IGBT chip using a controllable current source. Simultaneously record the output of all sensing units. Based on Obtain each element in the coupling matrix M.

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