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CN-122017517-A - SVPWM control-based IGBT module reactive aging test method

CN122017517ACN 122017517 ACN122017517 ACN 122017517ACN-122017517-A

Abstract

The application belongs to the technical field of reliability test of power electronic devices, in particular relates to an IGBT module reactive aging test method based on SVPWM control, and aims to solve the problems of current precision deviation, high energy consumption and insufficient real-time junction temperature monitoring in IGBT aging test. The method comprises the steps of constructing a reactive circulation loop based on an H-bridge topology, accurately reproducing working conditions through an SVPWM closed-loop control algorithm, extracting turn-off delay time by utilizing parasitic inductance induced voltage, inverting junction temperature in real time by combining a heat-sensitive parameter model, and predicting residual life by adopting an SSA optimized BP neural network. By adopting the scheme, the application can improve the voltage utilization rate, greatly reduce the test energy consumption and realize non-invasive junction temperature monitoring and high-precision failure early warning.

Inventors

  • LUO LING
  • CHEN DEJIN
  • HUANG RUI
  • YANG CHUNSHENG
  • QUAN GUANYU

Assignees

  • 中国测试技术研究院

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. The SVPWM control-based IGBT module reactive power aging test method is characterized by being implemented based on a multi-station synchronous test platform, wherein the platform comprises a high-voltage direct-current power supply, a bus capacitor group, an IGBT module to be tested, a three-phase load inductor, a main control unit, a driving circuit and a sensor acquisition system, and the method comprises the following steps of: s1, constructing a reactive circulation loop based on H-bridge topology, namely connecting an output end of a high-voltage direct-current power supply with a bus capacitor group in parallel, and electrically connecting the IGBT module to be tested with a three-phase load inductor through a three-phase full-bridge topology structure to form a closed loop with energy circulating and reciprocating between a direct-current bus and the inductor; S2, establishing a current closed-loop control model, wherein a main control unit acquires a three-phase current signal of an output end of an IGBT module to be detected through a sensor acquisition system, maps the three-phase current to a two-phase static coordinate system by utilizing a Clark conversion to obtain an alpha-axis current component i α and a beta-axis current component i β , and outputs coordinate components u α and u β of a reference voltage vector V ref on an alpha-beta plane through a proportional integral regulator; S3, executing space vector pulse width modulation SVPWM driving, wherein the main control unit judges the sector position of a reference voltage vector V ref according to u α and u β , calculates the acting time of adjacent effective vectors and zero vectors, generates seven-segment pulse signals, and applies the seven-segment pulse signals to the grid electrode of the IGBT module to be tested through a driving circuit; and S4, carrying out junction temperature real-time monitoring and aging evaluation, namely capturing turn-off transient induced voltage by using an auxiliary emitter parasitic inductance of an internal packaging structure of the IGBT module to be tested, extracting real-time junction temperature by using an inversion model, combining voltage, current and temperature data acquired by a sensor acquisition system, and outputting a residual reliable life result by using an aging state prediction model.
  2. 2. The method for testing reactive aging of an IGBT module based on SVPWM control according to claim 1, wherein the establishing a current closed-loop control model in step S2 specifically includes: A three-phase current sensor arranged at the output end of the three-phase full bridge synchronously collects U, V, W three-phase current signals i u 、i v 、i w ; The main control unit adopts a heterogeneous architecture based on an ARM processor and a field programmable gate array FPGA, the FPGA executes Clark transformation operation, a coordinate transformation matrix of the FPGA meets the power invariable constraint, and three-phase current signals are converted into components i α and i β under a two-phase static coordinate system in real time; performing difference operation on a preset sinusoidal reference current i ref and a feedback current, and inputting the difference operation to a proportional-integral regulator, wherein the transfer function expression of the proportional-integral regulator is as follows: G(s)=K p +K i /s; the proportional coefficient K p and the integral coefficient K i are obtained by carrying out parameter identification in advance through a pole allocation method based on the inductance L of the three-phase load inductance, the conduction internal resistance of the IGBT module to be tested and the expected closed-loop system time constant.
  3. 3. The method for testing reactive aging of an IGBT module based on SVPWM control according to claim 1, wherein the specific process of executing the SVPWM driving logic in step S3 is: The main control unit calculates the phase angle theta of the reference voltage vector V ref according to the coordinate components u α and u β , namely theta=arctan (u β /u α ), and divides the space vector diagram into six symmetrical sectors according to the phase angle theta; In the determined nth sector, the adjacent two effective vectors V x 、V y are utilized for synthesis based on the volt-second balance principle, and the acting time T 1 and T 2 of the effective vector V x 、V y are calculated by the following formula: T 1 =[3 1/2 T s |V ref |sin(nπ/3−θ)]/V dc ; T 2 =[3 1/2 T s |V ref |sin(θ−(n-1)π/3)]/V dc ; Wherein T s is PWM switching period, V dc is real-time measurement value of DC bus voltage, θ is phase angle of reference voltage vector V ref , and V ref is reference voltage vector; The generated six paths of pulse signals are subjected to dead time compensation processing in the FPGA, current zero crossing point distortion caused by dead time effect is eliminated by monitoring current polarity in real time and automatically superposing compensation voltage vectors in the FPGA, and the pulse signals are subjected to power amplification through an optocoupler isolation circuit in a driving circuit to drive switching action of an IGBT module to be tested.
  4. 4. The SVPWM control-based IGBT module reactive power aging test method according to claim 1, wherein the bus capacitor group is compounded by adopting a laminated bus bar technology, and comprises the following steps: The filter capacitor is connected in parallel with the front end of the direct current bus and used for inhibiting low-frequency voltage ripple introduced by the direct current side power supply; the support capacitor is used for storing and exchanging reactive energy fed back by the three-phase load inductance during the turn-off period of the IGBT module to be tested, and the capacity configuration of the support capacitor meets the condition that the voltage fluctuation rate of the direct current bus in the reactive circulation process is lower than 1%; the absorption capacitor is physically arranged at the positive and negative input ends of the direct-current bus close to the IGBT module to be tested, and is used for weakening voltage spikes of the IGBT module to be tested in a high-speed switching transient state by utilizing the characteristic of low equivalent series inductance.
  5. 5. The method for testing reactive aging of an IGBT module based on SVPWM control according to claim 1, wherein in step S4, the mechanism for extracting the real-time junction temperature includes: At the turn-off moment of the IGBT module to be tested, the change rate di c /d t of the collector current i c generates transient induction voltage v eE on the parasitic inductance of the auxiliary emitter; Capturing the waveform of the transient induced voltage v eE by a high-speed sampling circuit, wherein the high-speed sampling circuit adopts a differential input structure and is provided with a broadband low-pass filter, and the sampling rate is set to be more than 100 MSa/s; The main control unit identifies the voltage drop characteristic point of the v eE waveform, calculates the turn-off delay time t doff , and the turn-off delay time t doff is defined as the time difference between the moment when the gate driving signal falls to the turn-off threshold value and the moment when the collector current i c starts to fall.
  6. 6. The SVPWM control-based IGBT module reactive aging test method according to claim 5, wherein the main control unit uses the turn-off delay time T doff to invert the chip junction temperature T j in real time according to a pre-calibrated heat-sensitive parameter model: T j =k·t doff +b; Wherein k is a sensitivity coefficient, and b is a compensation constant; The sampling frequency of the inversion model is synchronous with the switching frequency of SVPWM, and the quasi-online monitoring of the junction temperature swing delta T j and the junction temperature change rate dT j /dT of the chip is realized.
  7. 7. The SVPWM control-based IGBT module reactive aging test method according to claim 5, wherein the method is further characterized by realizing vehicle-mounted working condition reproduction through decoupling control logic of an H-bridge topology, and specifically comprises the following steps: the main control unit simulates real-time fluctuation of active power P and reactive power Q in the vehicle dynamic process on the three-phase load inductance by adjusting the modulation ratio mm and the current phase angle of the SVPWM controller in real time, and the calculation relation of the real-time fluctuation follows a power formula under a synchronous rotation coordinate system: P= (u d i d +u q i q )·3/2; Q=(u q i d −u d i q )·3/2; Wherein u d ,u q is the d-axis and q-axis voltage components in the d-q coordinate system, and i d ,i q is the d-axis and q-axis current components in the d-q coordinate system, respectively; And (3) realizing pure reactive stress loading or composite current stress loading by controlling i d to be zero or fluctuating according to a preset curve.
  8. 8. The SVPWM control-based IGBT module reactive aging test method according to claim 1, wherein the test method adopts a constant shell temperature fluctuation control strategy to implement accelerated aging, and comprises the following specific steps: The main control unit adjusts the output duty ratio and the thermal cycle period of SVPWM in real time according to the shell temperature T c fed back by a thermocouple arranged at the central position of the bottom plate of the IGBT module to be tested, so that the IGBT module to be tested is circularly heated in a preset temperature fluctuation interval; The test platform further comprises a constant-temperature water cooling unit, the constant-temperature water cooling unit adopts a one-to-five independent circulation architecture, the main control unit is communicated with the constant-temperature water cooling unit through a Modbus TCP protocol, and according to the temperature rise and fall stage of the aging test, the proportional integral regulating valve and the variable-frequency water pump of the water cooling unit are cooperatively controlled, so that closed-loop regulation of the shell temperature change rate dT c /dT is realized.
  9. 9. The SVPWM control-based IGBT module reactive power aging test method according to claim 1, wherein the aging state prediction model is constructed based on an improved sparrow search algorithm SSA optimized BP neural network, and the prediction flow comprises: And (3) data preprocessing, namely filtering the collected original current, voltage, shell temperature and junction temperature data by adopting a three-time exponential smoothing method, wherein a smoothing operator iteration formula is as follows: S t (1) =α 1 y t +(1−α 1 )S t−1 (1) ; S t (2) =α 1 S t (1) +(1−α 1 ) S t−1 (2) ; S t (3)=α 1 S t (2) +(1−α 1 )S t−1 (3) ; wherein α 1 is a smoothing coefficient; Model optimization, namely initializing a sparrow population by utilizing a Tent chaotic map, and globally optimizing initial weights and thresholds of the BP neural network by simulating predation and defense behaviors of discoverers, joiners and early warning persons so as to minimize prediction errors; and outputting a result, namely inputting the preprocessed feature vector into the optimized neural network, and outputting a residual reliable life prediction value and a failure mechanism prediction result of the IGBT module to be tested.
  10. 10. The SVPWM control-based IGBT module reactive aging test method according to claim 1, wherein a voltage conditioning board card is arranged in a sensor acquisition system, a precise resistor voltage division structure is adopted, the voltage division ratio is set to be 0.01, and an RC compensation circuit is connected in parallel at the front end and used for converting a 1200V high-voltage signal into a 10V low-voltage signal; The water supply flow rate of the constant-temperature water cooling unit is set to be not lower than 2.6m 3 /h, the water temperature is controlled within the range of 10-85 ℃, and an online conductivity meter is integrated to monitor the quality of cooling water; the three-phase load inductor adopts star connection, the single-phase inductance is 0.1mH, the rated current effective value is 400A, and the temperature rise is limited within 95K.

Description

SVPWM control-based IGBT module reactive aging test method Technical Field The invention belongs to the technical field of reliability test of power electronic devices, and particularly relates to an IGBT module reactive aging test method based on SVPWM control. Background With the rapid development of the global new energy automobile industry, as a core energy conversion unit of a power electronic converter, the power density and the integration level of an Insulated Gate Bipolar Transistor (IGBT) module are continuously increased. Under the complex working condition of the vehicle, the IGBT module not only needs to bear extremely high current load, but also needs to frequently cope with current transient caused by starting, braking and speed change, so that the power semiconductor device is in the alternate impact of electric, thermal and mechanical stress for a long time. According to the theory of 'bathtub curve' in reliability engineering, failure mechanisms of packaging layers such as bonding wire falling off, solder layer fatigue and the like of the IGBT module are closely related to current output capability and internal junction temperature fluctuation in early service and whole life cycle. Therefore, before the device leaves the factory or in the research and development stage, a severe accelerated aging test is developed to verify the long-term service reliability of the device, and the development and development stage has become a key link for guaranteeing the safe operation of the whole vehicle. In the existing reliability evaluation system, in order to simulate a high-current running state while reducing energy consumption, technicians generally adopt a reactive aging test scheme based on an H-bridge topology. According to the scheme, three-phase load inductance is used for replacing a real motor load, and the circulation of inductive nonfunctional capacity and capacitive nonfunctional capacity is realized through energy exchange between the supporting capacitor and the load inductance. The design avoids large-scale loss of active power, so that the test equipment can generate huge circulating current under lower power grid input power, thereby inducing self-heating effect of the internal chip of the IGBT module and cyclic thermal stress circulation of the packaging structure of the IGBT module. However, with the increasingly stringent requirements of the automobile industry on performance indexes (switching frequency, thermal response speed, steady-state current precision, etc.) of the IGBT module, the conventional reactive aging test scheme gradually shows deep technical limitations in the aspects of principle and engineering implementation. First, the prior art mostly adopts an open loop control mode in terms of control strategies. During aging tests of hundreds or even thousands of hours, open loop control is difficult to maintain long-term stability of current amplitude and phase due to bus voltage fluctuations, ambient temperature drift, and parameter drift of the device under test due to aging. The defect in control precision can not only lead the test stress to deviate from the preset working condition, reduce the equivalence of reliability evaluation, but also cause abnormal damage of devices due to sudden overcurrent stress, and seriously affect the safety margin of the test. Meanwhile, the traditional modulation mode has a bottleneck in the aspects of harmonic suppression and bus voltage utilization rate under the working condition of processing large current, and accurate excitation of electromagnetic characteristics of the power module is difficult to realize in the high-frequency dynamic switching process. The more central contradiction is that there is a natural hedging between the real-time and accuracy of junction temperature (Junction Temperature) monitoring. The junction temperature is a core physical quantity for driving performance degradation and failure of the IGBT module, but because the power chip is packaged inside the module, the traditional physical contact measurement method (such as thermocouple or infrared temperature measurement) is limited by the response speed of the sensor and the blocking of a packaging structure, the detection deviation is often up to tens of degrees, and junction temperature fluctuation in a switching transient state cannot be captured at all. Although the technical field begins to explore the use of Thermally Sensitive Electrical Parameters (TSEP) for quasi-online junction temperature prediction, how to deeply fuse a complex electrical parameter extraction algorithm with a power modulation strategy in an actual reactive aging test flow still faces a great challenge. For example, the dynamic heat-sensitive parameter extraction based on the turn-off delay time is extremely easy to be interfered by parasitic inductance of a circuit and switching noise, and if the accurate signal conditioning and control logic support is lacked, the real-tim