IGBT module fault detection method and system based on harmonic sideband motion

Abstract

The invention relates to the technical field of power electronics, in particular to an IGBT (insulated gate bipolar transistor) module fault detection method and system based on harmonic sideband motion, which analyzes dynamic switching characteristics of a module, studies the influence of a bonding wire fault on an opening process, detects the fault through voltage harmonic change, and establishes a mapping relation between the bonding wire fault and conduction delay. A set of complete monitoring system is formed; the multi-chip IGBT module is simple in structure, easy to calibrate and realize during operation, and capable of efficiently identifying faults in the multi-chip IGBT module, thereby improving the operation reliability of the module, and effectively preventing system faults by timely finding potential problems through real-time monitoring; in future research, the method can be embedded into the power converter, and powerful theoretical and data support is provided for safe and reliable operation and state maintenance of the power converter.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to an IGBT module fault detection method and system based on harmonic sideband motion. Background Art

[0002] With the development of science and technology, power electronic systems in the fields of rail transportation, aerospace and other power energy are becoming increasingly complex. Power electronic converters are an important part of power electronic systems. Their responsibility is to achieve the conversion of electrical energy. This conversion process is completed by switching power devices. Power semiconductor devices are important components of the system, and their reliability determines the service life of the entire power electronic system.

[0003] IGBT is the most commonly used power semiconductor device, with the advantages of fast switching response and high current and voltage carrying capacity. However, with the reduction in the size of IGBT modules and the continuous increase in current and voltage levels, the electrical and thermal stresses inside the device are increasing, which in turn causes the device to fail and bring economic losses to the system. Therefore, the life, operating stability and failure factors of power devices will inevitably affect the entire converter and even the entire system, and in severe cases will cause the system to shut down. Research on the reliability of semiconductor power devices is of great significance to the entire power electronics system.

[0004] Bond wire shedding is the main cause of IGBT module failure. A single IGBT chip will fail to work due to an open circuit failure after all its bond wires fail. When some of the bond wires in a single IGBT module fail, the operating current will be redistributed to the remaining bond wires. At this time, the module can continue to operate, but the remaining bond wires will be subjected to a large current, causing the module to age faster. Therefore, chip failure caused by bond wire shedding can be regarded as a precursor to IGBT module failure.

[0005] In recent years, research on IGBT module reliability has focused on fault detection. Timely detection of the failed part of the module and timely formulation of corresponding maintenance measures can effectively ensure the operational reliability of the module. According to the detection principle, it can be mainly divided into two categories: (1) methods based on internal integrated sensors and (2) methods based on monitoring electrical parameters at the module end. In terms of methods based on internal integrated sensors, although this type of method can effectively detect the health status of each chip module inside the multi-chip module, it requires adjustment of the internal package layout of the module, which is highly invasive and difficult to implement. The method based on monitoring electrical parameters at the module end is a method of monitoring the module status based on electrical parameters such as quasi-threshold voltage, threshold voltage, charging time, module transconductance, and conduction voltage drop. Its advantage is that it is less invasive to the module. Among them, the method based on conduction voltage drop requires the addition of a measurement circuit with more complex clamping and isolation functions under high voltage and high current conditions, which is difficult to apply under high power conditions. Although the method based on gate signals has higher accuracy, the literature points out that in actual operation, due to the interference of monitoring signals and the fluctuation of gate signals, it is difficult to obtain a complete gate signal. Therefore, a simple and effective method is still needed for chip failure monitoring in multi-chip modules.

[0006] A new IGBT module bond wire detachment fault detection method is proposed, which detects IGBT chip faults by measuring the changes in three-phase voltage. This paper first analyzes the turn-on mechanism of the IGBT module. Secondly, the impact of bond wire failure on the turn-on process is analyzed, and it is found that the module turn-on delay and the number of failed bond wires have a strong correlation. Finally, based on the mapping relationship between turn-on delay and bond wire failure, a IGBT module bond wire detachment failure monitoring method based on voltage harmonic sideband fluctuations is proposed, and the accuracy and effectiveness of the method are verified through experiments. Summary of the invention

[0007] In view of the above problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the technical problem to be solved by the present invention is: by monitoring the turn-on delay and voltage harmonic sideband fluctuation caused by the IGBT module bonding wire detachment failure, an effective IGBT module fault detection method is proposed to ensure early detection of module internal faults, improve the operating reliability of power electronic equipment, and reduce the economic losses caused by equipment failures.

[0009] To solve the above technical problems, the present invention provides the following technical solutions: an IGBT module fault detection method based on harmonic sideband motion, comprising: analyzing the dynamic switching characteristics of the module; studying the impact of bonding wire failure on the turn-on process; detecting failures through voltage harmonic changes; and establishing a mapping relationship between bonding wire failure and turn-on delay.

[0010] As a preferred solution of the IGBT module fault detection method based on harmonic sideband motion described in the present invention, the dynamic switching characteristics include a turn-on process and a turn-off process, the gate voltage must rise to a threshold voltage before the IGBT is turned on, and the gate voltage must drop to a threshold voltage before the IGBT is turned off.

[0011] As a preferred solution of the IGBT module fault detection method based on harmonic sideband motion described in the present invention, the bonding wire failure includes aging and falling off of the bonding wire, and the impedance between the connecting parts of the bonding wire increases, that is, the impedance between the IGBT chip and the emitter terminal increases.

[0012] As a preferred solution of the IGBT module fault detection method based on harmonic sideband motion described in the present invention, wherein: the voltage harmonic change is based on the bonding wire failure, the dynamic switching characteristics of the module are changed, which is manifested in the turn-on delay; the bonding wire failure causes the three-phase voltage signal at the output end of the module to change, which is manifested in the harmonic components and harmonic amplitudes.

[0013] As a preferred solution of the IGBT module fault detection method based on harmonic sideband motion described in the present invention, wherein: the turn-on delay includes the time from the gate voltage rising to the threshold voltage. When the bonding wire fails, the internal impedance of the IGBT module increases, resulting in obstruction of the current conduction path, thereby increasing the turn-on delay.

[0014] As a preferred solution of the IGBT module fault detection method based on harmonic sideband motion described in the present invention, wherein: the turn-on process includes turn-on delay time, current rise time and turn-on time; the turn-on delay time is measured by measuring the change of gate signal and conduction current, that is, the time required from the gate-emitter voltage UGE generating front edge to 10% of its amplitude to the collector current rising to 10% of its amplitude; the current rise time includes the time required for the collector current to rise from 10% to 90% of its amplitude; the turn-on time includes the time required from the gate-emitter voltage UGE generating front edge to the collector current rising to 90% of its amplitude, that is, the sum of the turn-on delay time and the current rise time;

[0015] The turn-off process is affected by the on-current and the gate voltage, that is, the measurement of the turn-off process requires measuring the change of the on-current and a more complex isolation circuit to detect the change of the collector-emitter voltage.

[0016] As a preferred solution of the IGBT module fault detection method based on harmonic sideband motion described in the present invention, wherein: the harmonic component includes a DC component, and the fault of the IGBT module is detected by analyzing the changes in the harmonic components of different frequencies;

[0017] The harmonic amplitude, when the turn-on delay increases, the fundamental amplitude of the module decreases; when the turn-on delay increases, the amplitude of the higher harmonics increases.

[0018] Another object of the present invention is to provide an IGBT module fault detection system based on harmonic sideband movement, which monitors the health status of the IGBT module bonding wires in real time by analyzing the changing rules of the voltage harmonic sidebands, ensuring effective detection and early warning in the early fault stage, thereby improving the stability and safety of the system operation.

[0019] In order to solve the above technical problems, the present invention provides the following technical solutions: an IGBT module fault detection system based on harmonic sideband motion, comprising: a switch feature module, a fault impact module, a harmonic detection module and a mapping relationship module;

[0020] The switch feature module analyzes the dynamic switch features of the module;

[0021] The fault impact module studies the impact of bonding wire failure on the turn-on process;

[0022] The harmonic detection module detects faults through voltage harmonic changes;

[0023] The mapping relationship module establishes a mapping relationship between bonding wire failure and conduction delay.

[0024] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the IGBT module fault detection method based on harmonic sideband motion as described above are implemented.

[0025] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the IGBT module fault detection method based on harmonic sideband motion as described above are implemented.

[0026] The beneficial effects of the present invention are as follows: the method is a monitoring method that is easy to calibrate and implement during operation, and can effectively identify faults in multi-chip modules, thereby improving the operational reliability of IGBT modules; in future research, the method can be embedded in power converters to provide theoretical and data support for their safe and reliable operation and condition maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0028] Figure 1 A flow chart of an IGBT module fault detection method based on harmonic sideband motion provided by one embodiment of the present invention.

[0029] Figure 2 An IGBT turn-on process diagram of an IGBT module fault detection method based on harmonic sideband motion provided by an embodiment of the present invention.

[0030] Figure 3 An IGBT circuit working model diagram of an IGBT module fault detection method based on harmonic sideband motion provided by an embodiment of the present invention.

[0031] Figure 4 A diagram of a PWM wave generation process of an IGBT module fault detection method based on harmonic sideband motion provided by an embodiment of the present invention.

[0032] Figure 5 A measured turn-on waveform diagram of a failed IGBT module according to an IGBT module fault detection method based on harmonic sideband motion provided by an embodiment of the present invention.

[0033] Figure 6 A simulated conduction process curve diagram of IGBTs with different numbers of bonding wires according to an IGBT module fault detection method based on harmonic sideband motion provided by an embodiment of the present invention.

[0034] Figure 7 A diagram of dynamic characteristic simulation changes of IGBTs with different numbers of bonding wires according to an IGBT module fault detection method based on harmonic sideband motion provided by an embodiment of the present invention.

[0035] Figure 8 A physical picture of a test bench for an IGBT module fault detection method based on harmonic sideband motion provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0037] Example 1, reference Figure 1 , is an embodiment of the present invention, which provides an IGBT module fault detection method based on harmonic sideband motion, comprising:

[0038] Analyze the dynamic switching characteristics of the module;

[0039] Study the impact of bond wire failure on the turn-on process;

[0040] Detect faults through voltage harmonic changes;

[0041] Establish a mapping relationship between bonding wire failure and turn-on delay.

[0042] It should be noted that the dynamic switching process of the IGBT module includes two stages: turn-on and turn-off. During the normal operation of the module, changes in the gate voltage trigger a response in the collector current. By analyzing the dynamic switching characteristics of the module, we can gain an in-depth understanding of the working principle of the IGBT module. The dynamic characteristics of the module mainly include key parameters such as switching response speed and turn-on delay.

[0043] Furthermore, the falling off or aging of the bonding wire will directly affect the conduction performance of the IGBT module, which is manifested as an increase in internal resistance, which in turn leads to an increase in the conduction delay; when the bonding wire is aged, falls off, or other faults occur, it will cause the internal impedance of the module to increase, and the current conduction will slow down, which will directly affect the turn-on delay; when the IGBT module fails, the three-phase voltage signal at the output end will undergo harmonic changes; in particular, the main frequency amplitude decreases and the higher harmonic amplitude increases. These changes can be identified through spectrum analysis, and the fault of the bonding wire can be detected; the failure of the bonding wire will cause harmonic distortion in the voltage signal of the IGBT module, especially the main frequency amplitude decreases and the higher harmonic amplitude increases; by analyzing the changes in the harmonic components in the output voltage, the signs of bonding wire failure can be effectively captured, and early warning of module failure can be achieved.

[0044] Furthermore, as the bonding wire fails, the turn-on delay increases linearly; by establishing this mapping model, the fault condition of the bonding wire can be quantitatively analyzed by monitoring the change in the turn-on delay, providing an accurate basis for fault diagnosis.

[0045] Example 2, reference Figure 2-Figure 5 , is an embodiment of the present invention, which provides an IGBT module fault detection method based on harmonic sideband motion, comprising:

[0046] S1: Analyze the dynamic switching characteristics of the module.

[0047] It should be noted that the dynamic switch characteristics include the turn-on process and the turn-off process. The gate voltage must rise to the threshold voltage before the IGBT is turned on, and the gate voltage must drop to the threshold voltage before the IGBT is turned off. The turn-on process includes the turn-on delay time, the current rise time, and the turn-on time. The turn-on delay time is measured by measuring the changes in the gate signal and the on-current, that is, from the gate-emitter voltage U GEThe time required for the collector current to rise to 10% of its amplitude from the generation front edge to 10% of its amplitude; the current rise time includes the time required for the collector current to rise from 10% to 90% of its amplitude; the turn-on time includes the time required for the gate-emitter voltage U GE The time required from the generation of the leading edge to the collector current rising to 90% of its amplitude is the sum of the turn-on delay time and the current rise time; the turn-off process is affected by the on-current and the gate voltage, that is, the measurement of the turn-off process requires measuring the change of the on-current and a more complex isolation circuit to detect the change of the collector-emitter voltage.

[0048] Further, such as Figure 2 As shown, the opening delay time t d (on): From the gate-emitter voltage U GE The leading edge rises to 10% of its amplitude until the collector current I C The time required to rise to 10% of its amplitude; current rise time t r : Collector current I C The time required to increase from 10% to 90% of the amplitude; the opening time t on : From the gate-emitter voltage U GE Generates leading edge to collector current I C The time required for the current to rise to 90% of its amplitude is the sum of the turn-on delay time and the current rise time.

[0049] S2: Study the impact of bond wire failure on the turn-on process.

[0050] It should be noted that the failure of the bonding wire includes the phenomenon of aging and falling off of the bonding wire, which increases the impedance between the bonding wire connection parts, that is, the impedance between the IGBT chip and the emitter terminal. According to the analysis of the working state of the IGBT, its equivalent circuit is as follows: Figure 3 As shown;

[0051] Further, in Figure 3 In, R g is the gate resistance, which is determined by the IGBT module packaging circuit; C gc is the parasitic capacitance between the chip collector and gate, C gc It is the parasitic capacitance between the chip gate and emitter. The parasitic capacitance is determined by the length and width of the chip internal channel. Zbandwires is the impedance of the bonding wire, which is determined by the aging degree of the bonding wire. When the bonding wire is abnormal, the impedance increases. c (t) is the current passing through the IGBT. In closed-loop control, the current flowing through the CE will tend to be stable under the action of the current loop. When Zbandwires increases, that is, the impedance of the power device increases, the voltage V CEand the increase of turn-on delay time; since the inductance change caused by the abnormal bonding wire can be ignored, the increase of internal resistance is used to simulate the aging of the bonding wire of the power device.

[0052] S3: Fault detection through voltage harmonic changes.

[0053] It should be noted that the voltage harmonic changes according to the bonding wire failure, the dynamic switching characteristics of the module change, which is manifested in the turn-on delay; the bonding wire failure causes the three-phase voltage signal at the output of the module to change, which is manifested in the harmonic components and harmonic amplitudes;

[0054] Harmonic components include DC components. By analyzing the changes in harmonic components of different frequencies, faults of IGBT modules can be detected.

[0055] Harmonic amplitude: when the turn-on delay increases, the fundamental amplitude of the module decreases; when the turn-on delay increases, the amplitude of the higher harmonics increases.

[0056] Furthermore, taking a permanent magnet synchronous motor and its motor controller as an example, the action of the motor is controlled by a PWM wave generated by an inverter; the generation of the PWM wave is as follows: Figure 4 As shown;

[0057] Where ω1 is the target current frequency for controlling the motor rotation in the SPWM inverter circuit; ω s is the switching frequency of the IGBT module when it is switched on; after considering the conduction delay caused by the failure of the IGBT module, the measured PWM waveform is as follows Figure 5 shown.

[0058] S4: Establish a mapping relationship between bonding wire failure and turn-on delay.

[0059] It should be noted that the turn-on delay includes the time from the gate voltage rising to the threshold voltage. When the bonding wire fails, the internal impedance of the IGBT module increases, resulting in obstruction of the current conduction path and increasing the turn-on delay.

[0060] Furthermore, ω1 is the modulation wave frequency in the SPWM inverter circuit; ω s is the carrier frequency; Ma is the modulation ratio; Ma sin(ω1t) is the modulation wave size; the sine wave average symmetric regular sampling method is adopted;

[0061] According to the sine wave average symmetry rule sampling method, we can get:

[0062]

[0063] With carrier angular frequency ω s , the modulation wave interval [-π,π] is taken as the reference, and the DC bus line voltage is set to E d , 2U A / Ed Doing Fourier expansion gives:

[0064]

[0065] Where n = 1, 2, 3, ...

[0066] Combining and sorting, we can deduce:

[0067]

[0068] Considering the IGBT switching delay characteristics, it is assumed that the IGBT will be triggered after t d,on After the delay, it turns on and loses the trigger signal after t d，off If it is turned off after a delay, then:

[0069]

[0070] After finishing, we can get:

[0071]

[0072] It can be clearly seen from the formula that the phase voltage U A A new DC component is added to the fundamental wave component, and its amplitude is (E d / nπ)·t Δ , for U A The harmonic expression is decomposed and deduced as follows:

[0073]

[0074] f 1t =cost Σ cost Δ ,f 2t =sint ∑ sint Δ ,

[0075] f 3t =cost ∑ sint Δ ,f 4t =sint ∑ cost Δ

[0076] When n = 1, 3, 5, ..., there exists:

[0077] cos(nπ / 2)=0

[0078] sin(nπ / 2)=(-1)(n-1) / 2

[0079] From this, we can further obtain the phase voltage U A Harmonic expressions:

[0080]

[0081] When k = 1 and n = 1, the phase voltage U A The harmonic expression is:

[0082]

[0083] At this time, the phase voltage U A The corresponding high-order harmonics and their side harmonic amplitudes are reduced, so the bond wire detachment of the IGBT module can be detected by analyzing the changes in the spectrum characteristics of the three-phase voltage at the output end of the motor.

[0084] The above is a schematic scheme of an IGBT module fault detection method based on harmonic sideband motion in this embodiment. It should be noted that the technical scheme of the system of the IGBT module fault detection method based on harmonic sideband motion and the technical scheme of the IGBT module fault detection method based on harmonic sideband motion above belong to the same concept, and the details not described in detail in the technical scheme of the IGBT module fault detection system based on harmonic sideband motion in this embodiment can all be referred to the description of the technical scheme of the IGBT module fault detection method based on harmonic sideband motion above.

[0085] Example 3, reference Figure 6-Figure 8 An embodiment of the present invention provides an IGBT module fault detection method based on harmonic sideband motion. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0086] The change of the turn-on delay time is only related to the threshold voltage and RC time parameters of the chip, and has nothing to do with the bus voltage and on-current of its working condition. When the IGBT fails due to bond wire shedding, the resistance in the loop increases due to the reduction in the number of bond wires, and the time constant of the charging loop increases, which reduces the charging speed of the Miller capacitance and the gate-source capacitance. Since the inductance change caused by the abnormal bond wire can be ignored, the increase in internal resistance is used in this paper to simulate the aging of the bond wire of the power device.

[0087] During the simulation process, a total of 5 IGBT models were established, and their bond resistance values ​​were set to 1.1Ω, 1.3Ω, 1.6Ω, 2.2Ω, and 3.3Ω, respectively, to simulate the IGBT bond wire failure modules with the number of bond wires being 12, 10, 8, 6, and 4. The model with 12 bond wires, i.e., a bond resistance of 1.1Ω, is the IGBT model in a healthy state.

[0088] The dynamic model of IGBT is implemented by Simplorer, while the motor and its control circuit are in Simulink. Therefore, the fault simulation of the bonding wire failure of the IGBT module is jointly simulated using Simplorer and Simulink. In the joint simulation, Simplorer is used for inverter circuit modeling, and Simulink is used for circuit control and motor corresponding output. Simplorer uses the line voltage of the inverter circuit where the IGBT is located as output, which is used as the input of the motor model in Simulink; Simulink outputs the SVPWM signal obtained by the current loop and voltage loop control to the IGBT to control its on and off, and finally realizes the coupling simulation between multiple physical fields.

[0089] The double pulse test circuit is used to measure the IGBT modules with different numbers of bonding wires. The turn-on process curves of each IGBT module are shown in the figure below. Figure 6 As shown, it can be clearly observed that as the number of bonding wires decreases, the turn-on delay of the IGBT module gradually increases and the turn-on rate slows down.

[0090] The simulation results are consistent with the theoretical analysis results, which proves the effectiveness of the faulty IGBT model established in this paper.

[0091] The established IGBT module is added to the simulation test circuit to observe the frequency spectrum characteristics of the motor output voltage.

[0092] FE is the sum of the amplitude decrease of the main frequency 7000Hz in the three-phase voltage spectrum compared to the healthy state and the amplitude increase of its third harmonic 21000Hz. The main frequency is related to the specific control algorithm inside the motor controller and is generally set to a fixed value.

[0093] After the bonding wire of the IGBT module falls off, its turn-on delay increases; after the turn-on delay increases, the amplitude of the 7000Hz main frequency of the signal decreases, and the amplitude of the harmonics increases. This is because the turn-on delay increases, the system response speed slows down, the actual voltage value deviates from the ideal voltage value, and more prominent harmonic components are generated, resulting in a decrease in the amplitude of the main frequency; the experimental results are shown in Table 1 below:

[0094] Table 1 Experimental results

[0095]

[0096]

[0097] For IGBT, the physical essence of the failure of its bonding wires falling off is the increase of resistance value at the bonding wires. In order to simulate the degradation process of IGBT modules, the number of bonding wires needs to be changed. If the effective number of IGBT bonding wires is changed by cutting, the module package needs to be opened, the glue is removed, and then the bonding wires are cut. If static electricity is generated during this process, the IGBT chip is very likely to break down. For this reason, the fault implantation method of the IGBT module is to customize the IGBT module with different numbers of bonding wires.

[0098] The customized module reduces the number of healthy IGBT bonding wires from 12 per IGBT chip to 6, 8, and 10, simulating two types of failure scenarios: IGBT modules with different degrees of aging of three single chips and synchronous degradation of the entire module. Considering that the bonding wires of a chip may fall off more seriously during the degradation process, an additional IGBT module with 4 bonding wires on a single bridge arm was customized.

[0099] The IGBT used is a three-phase full-bridge module, and the module model is LDG400F07AJRD3CA. The specific customization requirements of each module are shown in Table 2 below:

[0100] Table 2 Specific customization requirements for each module

[0101]

[0102] Seven motor controllers were purchased to match the above-mentioned IGBT modules. By replacing the customized IGBTs into the motor controllers, fault simulation of the IGBT modules can be realized, and fault simulation experimental data can be obtained using the constructed test bench.

[0103] The experiment was conducted on the bond wire detachment fault of the IGBT module in the motor driver, with the aim of exploring the relationship between the bond wire detachment fault and the response of the motor output. For this purpose, different numbers of bond wires were customized to simulate IGBT modules with different fault levels, and the three-phase voltage signals were collected and analyzed during the stable operation of the motor; in addition, multiple working conditions with different speeds and torques were set up to verify the versatility and effectiveness of the algorithm obtained under different working conditions, and to obtain the optimal working condition for using the algorithm.

[0104] The selection of the working condition of the IGBT module is analyzed based on the experimental and simulation methods. From the perspective of torque, the introduction of the load will cause the speed of the permanent magnet synchronous motor to pulsate periodically. At high speed, the speed pulsation amplitude is relatively small due to the large momentum of the rotor; but at low speed, the speed will produce a large pulsation amplitude, causing greater vibration; the large speed pulsation at low speed leads to the fluctuation of the frequency domain characteristics of the three-phase voltage. Therefore, a lower torque condition should be selected as much as possible.

[0105] From the perspective of speed, simulation methods were used to explore the working conditions at different speeds, and the three-phase voltage spectrum is shown in the figure.

[0106] From the simulation results, it can be seen that as the motor speed increases, its main frequency amplitude gradually decreases and the sideband amplitude gradually increases. This is because the increase in motor speed will lead to an increase in the back electromotive force inside the motor, and the back electromotive force can be a voltage value that represents the speed. Therefore, as the speed increases, the sideband amplitude will increase significantly; while the total energy is fixed, so the main frequency amplitude will decrease. In order to observe the main frequency and sideband changes more comprehensively and accurately, the speed should be within 1250~2000rpm. At the same time, in order to consider the convenience of rounding the electrical frequency, the working condition of 1500rpm and 0Nm was selected for analysis.

[0107] The measured voltage signal is analyzed and found to still conform to the above rules. As shown in Tables 3 and 4 below, for the degradation of the IGBT chip, as the number of bonding wires decreases, the amplitude of the 7000Hz main frequency gradually decreases, and the amplitude of its third harmonic 21kHz increases, which is consistent with the change trend of the saturation voltage drop value. Therefore, the main frequency and its harmonic increase and decrease method is used to measure the early IGBT bonding wire degradation. The health factor constructed by the main frequency and its harmonic increase and decrease method is defined as FE, which is equal to the sum of the amplitude decrease of 7000Hz and the amplitude increase of 21000Hz in the three-phase voltage spectrum compared to the healthy state.

[0108] By comparing the changes in the main frequency and its harmonics with the changes in the saturation voltage drop, it can be clearly seen that the newly constructed health factor has the same change trend and change law as the saturation voltage drop, proving that this indicator has a relatively sensitive and accurate response to the health of the IGBT and can be used as a health factor. The main frequency of 7kHz and its third harmonic amplitude change under the conditions of 1500rpm and 0Nm are used as the health factor FE. When the measured FE increases by 4% compared with the calibrated reference value, an early warning is issued, indicating that the number of IGBT chip bonding wires at a certain position in the IGBT module has changed.

[0109] Table 3 Rule 1

[0110]

[0111]

[0112] Table 4 Rule 2

[0113]

[0114] Embodiment 4 is an embodiment of the present invention, which provides an IGBT module fault detection system based on harmonic sideband motion, including: a switch feature module, a fault impact module, a harmonic detection module and a mapping relationship module;

[0115] The switch feature module analyzes the dynamic switch features of the module;

[0116] The fault impact module studies the impact of bonding wire failure on the turn-on process;

[0117] The harmonic detection module detects faults through voltage harmonic changes;

[0118] The mapping relationship module establishes a mapping relationship between bonding wire failure and conduction delay.

[0119] This embodiment further provides a computing device, which is applicable to the case of an IGBT module fault detection method based on harmonic sideband motion, including:

[0120] A memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the IGBT module fault detection method based on harmonic sideband motion as proposed in the above embodiment.

[0121] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the IGBT module fault detection method based on harmonic sideband motion as proposed in the above embodiment is implemented.

[0122] The storage medium proposed in this embodiment and the IGBT module fault detection method based on harmonic sideband motion proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0123] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0124] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0125] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0126] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An IGBT module fault detection method based on harmonic sideband motion, characterized in that: include: Analyze the dynamic switching characteristics of the module; Study the impact of bond wire failure on the turn-on process; Detect faults through voltage harmonic changes; Establish a mapping relationship between bonding wire failure and turn-on delay.

2. The IGBT module fault detection method based on harmonic sideband motion according to claim 1, characterized in that: The dynamic switch characteristics include a turn-on process and a turn-off process. The gate voltage must rise to a threshold voltage before the IGBT is turned on, and the gate voltage must drop to a threshold voltage before the IGBT is turned off.

3. The IGBT module fault detection method based on harmonic sideband motion according to claim 2, characterized in that: The bonding wire failure includes the phenomenon that the bonding wire is aged and falls off, and the impedance between the connecting parts of the bonding wire increases, that is, the impedance between the IGBT chip and the emitter terminal increases.

4. The IGBT module fault detection method based on harmonic sideband motion according to claim 3, characterized in that: The voltage harmonic change is due to the bonding wire failure, and the dynamic switching characteristics of the module are changed, which is manifested in the turn-on delay; the bonding wire failure causes the three-phase voltage signal at the output end of the module to change, which is manifested in the harmonic components and harmonic amplitudes.

5. The IGBT module fault detection method based on harmonic sideband motion according to claim 4, characterized in that: The turn-on delay includes the time from the gate voltage rising to the threshold voltage. When the bonding wire fails, the internal impedance of the IGBT module increases, resulting in obstruction of the current conduction path, which increases the turn-on delay.

6. The IGBT module fault detection method based on harmonic sideband motion according to claim 5, characterized in that: The turn-on process includes turn-on delay time, current rise time and turn-on time; the turn-on delay time is measured by measuring the change of gate signal and conduction current, that is, the time required from the gate-emitter voltage UGE generating front edge rising to 10% of its amplitude to the collector current rising to 10% of its amplitude; The current rise time includes the time required for the collector current to rise from 10% to 90% of its amplitude; the turn-on time includes the time required from the gate-emitter voltage UGE to the collector current to rise to 90% of its amplitude, that is, the sum of the turn-on delay time and the current rise time; The turn-off process is affected by the on-current and the gate voltage, that is, the measurement of the turn-off process requires measuring the change of the on-current and a more complex isolation circuit to detect the change of the collector-emitter voltage.

7. The IGBT module fault detection method based on harmonic sideband motion according to claim 6, characterized in that: The harmonic components include DC components, and the fault of the IGBT module is detected by analyzing the changes of harmonic components of different frequencies; The harmonic amplitude, when the turn-on delay increases, the fundamental amplitude of the module decreases; when the turn-on delay increases, the amplitude of the higher harmonics increases.

8. A system for IGBT module fault detection based on harmonic sideband motion according to any one of claims 1 to 7, characterized in that: include: Switch feature module, fault impact module, harmonic detection module and mapping relationship module; The switch feature module analyzes the dynamic switch features of the module; The fault impact module studies the impact of bonding wire failure on the turn-on process; The harmonic detection module detects faults through voltage harmonic changes; The mapping relationship module establishes a mapping relationship between bonding wire failure and conduction delay.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the IGBT module fault detection method based on harmonic sideband motion according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the IGBT module fault detection method based on harmonic sideband motion according to any one of claims 1 to 7 are implemented.

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