Test method for simulating calculation of junction temperature of IGBT module by energy storage converter

Abstract

The invention discloses a test method for simulating and calculating the junction temperature of an IGBT module of an energy storage converter, and the method comprises the steps: obtaining the temperature of a copper substrate of the IGBT module, building a simulation calculation model according to the transient thermal resistance parameter and operation condition of the IGBT module, and finally obtaining the average junction temperature, the maximum junction temperature and the junction temperature fluctuation of an internal chip of the IGBT module through the model calculation. Compared with an existing traditional testing method, the testing method can safely, stably and reliably obtain testing data, a simulation calculation method can obtain the average junction temperature of a chip in the IGBT module, the maximum junction temperature and junction temperature fluctuation can also be obtained, the heat dissipation design of the IGBT module can be objectively evaluated, and the operation working state of the IGBT module can be comprehensively evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage converters, and in particular to the technical field of a test method for simulating and calculating the junction temperature of an IGBT module of an energy storage converter. Background Art

[0002] With the popularization of new energy and the growth of the demand for intelligent power grids, energy storage converters are playing an increasingly important role in the fields of new energy power generation, power systems, distributed energy, etc. As the core component of energy storage converters, the operating status of IGBT modules directly affects the performance and reliability of energy storage converters. IGBT modules will produce losses during operation and convert them into heat, resulting in increased junction temperature. Reducing the junction temperature of IGBT modules can improve their performance and reliability. Effective heat dissipation design is required. Junction temperature is an effective basis for evaluating the heat dissipation design of IGBT modules. Therefore, the junction temperature of IGBT modules is related to the overall reliability of energy storage converters. The existing traditional testing method is to directly test the temperature measurement points on the surface of the chip inside the IGBT module. Figure 1 The figure shows the existing traditional test diagram of directly testing the temperature measurement points on the surface of the chip inside the IGBT module. There is a risk that the temperature measurement point is not in full contact with the chip surface, resulting in excessive temperature measurement deviation, and high voltage is introduced into the thermometer. Summary of the invention

[0003] The purpose of the present invention is to solve the problems in the prior art and to propose a test method for simulating and calculating the junction temperature of an IGBT module for an energy storage converter, which can obtain test data safely, stably and reliably. The simulation calculation method can not only obtain the average junction temperature of the chip inside the IGBT module, but also obtain the maximum junction temperature and junction temperature fluctuation, which can objectively evaluate the heat dissipation design of the IGBT module and comprehensively evaluate the operating status of the IGBT module.

[0004] To achieve the above object, the present invention proposes a test method for simulating and calculating the junction temperature of an IGBT module of an energy storage converter, comprising the following steps: Step 1: Check the IGBT module chip layout diagram, make slots and holes in the copper substrate at the center of each chip inside the IGBT module to embed the thermocouple, then pour silver paste into the slots where the thermocouple is embedded and solidify to fill the gaps, and process the surface of the silver paste filled part to be flush with the surface of the copper substrate; Step 2: Apply interface material to the surface of the IGBT module processed in step 1, then install and fix the IGBT module on the heat sink to assemble it into a complete power unit, and then install the power unit on the energy storage converter; Step 3: Set the operating conditions of the energy storage converter, and measure the steady-state temperatures at the positions of the copper substrates directly below chips A, B, C, and D in the IGBT module through pre-embedded thermocouples. The temperature values are respectively denoted as Ta, Tb, Tc, and Td; Step 4: Input operating parameters such as input voltage, current, frequency, switching frequency, modulation mode, modulation ratio, and power factor for simulation calculation to obtain the power losses of the upper and lower IGBT chips and Diode chips, which are respectively denoted as Pa(t), Pb(t), Pc(t), and Pd(t); Step 5: Substitute the power losses of each chip calculated in Step 4 into the foster thermal resistance network model composed of the transient thermal resistance curve models of the IGBT chip and the Diode chip to calculate the junction temperature curve equation Tj(t) of each chip: ; Step 6: Obtain the maximum junction temperature Tjmax, average junction temperature Tjav, and junction temperature fluctuation ΔTj of each chip under steady-state operating conditions through the Tj(t) curve equation, and comprehensively evaluate whether the heat dissipation design of the IGBT module is reasonable based on the obtained maximum junction temperature Tjmax, average junction temperature Tjav, and junction temperature fluctuation ΔTj.

[0005] Preferably, in Step 1, the position and method of pre-embedding thermocouple temperature measurement points on the copper substrate of the IGBT module are specifically as follows: Select the grooved position of the copper substrate of the IGBT module, set the groove size according to the shape and size of the thermocouple, set the pre-embedding position of the thermocouple according to the groove size, fill and fix the groove for pre-embedding the thermocouple with silver paste, level the surface of the silver paste until it is flush with the surface of the copper substrate, then seal it with tape, and remove the tape after the silver paste is cured.

[0006] Preferably, in Step 3, directly obtain the temperatures of the copper substrates directly below chips A, B, C, and D through pre-embedded thermocouples.

[0007] Preferably, in Step 4, the simulation calculation of the power loss is performed through the simulation calculation tool provided by the IGBT module manufacturer or a self-built model.

[0008] Advantages of the present invention: By obtaining the temperature of the copper substrate of the IGBT module, then establishing a simulation calculation model based on the transient thermal resistance parameters and operating conditions of the IGBT module, and finally obtaining the average junction temperature, maximum junction temperature, and junction temperature fluctuation of the chips inside the IGBT module through model calculation. The testing method involved in the present invention can obtain test data safely, stably, and reliably compared with the existing traditional testing methods. The simulation calculation method can not only obtain the average junction temperature of the chips inside the IGBT module, but also obtain the maximum junction temperature and junction temperature fluctuation, which can objectively evaluate the heat dissipation design of the IGBT module and comprehensively evaluate the operating state of the IGBT module.

[0009] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. Description of the Drawings

[0010] Figure 1 is a test diagram of directly measuring the temperature points on the surface of the internal chips of the IGBT module by the existing traditional test method; Figure 2 is a layout diagram of the chips inside the IGBT module of a test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention; Figure 3 and Figure 4 is a diagram of the center positions of the IGBT chip and the Diode chip where the cut-off position of the copper substrate slot is for a test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention; Figure 5 is a physical diagram of the slot of the IGBT module of a test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention; Figure 6 is a physical diagram of the IGBT module after silver paste is filled and cured after embedding the thermocouple for a test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention; Figure 7 is a transient thermal resistance model curve of the IGBT chip and the Diode chip inside the IGB module of a test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention; Figure 8 is a junction temperature fluctuation curve of the IGBT chip and the Diode chip of a test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention. Detailed Embodiments

[0011] Refer to Figure 3 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 A test method for simulating and calculating the junction temperature of the IGBT module for an energy storage converter according to the present invention includes the following steps: Step 1: Consult the chip layout diagram of the IGBT module, as shown in Figure 2 , make slots and holes in the copper substrate at the center positions of each chip inside the IGBT module to embed thermocouples, then pour silver paste into the slots and holes where the thermocouples are embedded to cure and fill the gaps, and process the surface of the silver paste filling part to be flush with the surface of the copper substrate; Step 2: Apply the interface material on the surface of the IGBT module processed in Step 1, then install and fix the IGBT module on the radiator to assemble a complete power unit, and install the power unit on the energy storage converter; Step 3: Set the operating conditions of the energy storage converter, as shown in Figure 2 , and measure the steady-state temperatures at the positions of the copper substrates directly below Chips A, B, C, and D in the IGBT module by embedding thermocouples. The temperature values are denoted as Ta, Tb, Tc, and Td respectively; Step 4: Input operating parameters such as input voltage, current, frequency, switching frequency, modulation mode, modulation ratio, and power factor to simulate and calculate the power losses of the upper and lower IGBT chips and Diode chips, which are denoted as Pa(t), Pb(t), Pc(t), and Pd(t) respectively; Step 5: As shown in Figure 7 , substitute the power losses of each chip calculated in Step 4 into the foster thermal resistance network model composed of the transient thermal resistance curve models of the IGBT chips and Diode chips, as shown in Figure 8 , and calculate the junction temperature curve equations Tj(t) of each chip: ; Step 6: Obtain the maximum junction temperature Tjmax, average junction temperature Tjav, and junction temperature fluctuation ΔTj of each chip under steady-state operating conditions through the Tj(t) curve equation, and comprehensively evaluate whether the heat dissipation design of the IGBT module is reasonable based on the obtained maximum junction temperature Tjmax, average junction temperature Tjav, and junction temperature fluctuation ΔTj; In Step 1, the positions and methods for embedding thermocouple temperature measurement points on the copper substrate of the IGBT module are specifically as follows: Select the grooved position of the copper substrate of the IGBT module, set the groove size according to the shape and size of the thermocouple, set the thermocouple embedding position according to the groove size, fill and fix the groove for embedding the thermocouple with silver paste, level the surface of the silver paste until it is flush with the surface of the copper substrate and then seal it with tape. After the silver paste cures, remove the tape. In Step 3, directly obtain the temperatures of the copper substrates directly below Chips A, B, C, and D through the embedded thermocouples. In Step 4, the simulation and calculation of the power losses are performed using the simulation calculation tool provided by the IGBT module manufacturer or a self-built model.

[0012] In the present invention, a thermocouple is embedded by grooving or drilling the copper substrate of the IGBT module, and the temperature of the copper substrate is obtained during the test operation. Then, according to the operating conditions, the loss power of each chip in the IGBT module under the corresponding conditions is simulated and calculated. Finally, by combining the temperature of the copper substrate of the IGBT module obtained by the test and the loss power of each chip in the IGBT module obtained by the simulation calculation, through the Foster thermal resistance network model constructed by the transient thermal resistance parameter model of the IGBT module, the maximum junction temperature, average junction temperature and junction temperature fluctuation of the chips inside the IGBT module are calculated and obtained.

[0013] The above embodiments are illustrative of the present invention and not restrictive thereof. Any solution obtained by simply transforming the present invention falls within the protection scope of the present invention.

Claims

1. A test method for simulating and calculating the junction temperature of an IGBT module in an energy storage converter, characterized in that: The steps include: Step 1: Check the IGBT module chip layout diagram, make slots and holes in the copper substrate at the center of each chip inside the IGBT module to embed the thermocouple, then pour silver paste into the slots where the thermocouple is embedded and solidify to fill the gaps, and process the surface of the silver paste filled part to be flush with the surface of the copper substrate; Step 2: Apply interface material to the surface of the IGBT module processed in step 1, then install and fix the IGBT module on the heat sink to assemble it into a complete power unit, and then install the power unit on the energy storage converter; Step 3: Set the operating conditions of the energy storage converter, and measure the steady-state temperature of the copper substrate directly below chip A, chip B, chip C, and chip D in the IGBT module through the pre-buried thermocouples. The temperature values ​​are recorded as Ta, Tb, Tc, and Td respectively. Step 4: The input voltage, current, frequency, switching frequency, modulation mode, modulation ratio and power factor and other operating parameters are simulated and calculated to obtain the power loss of the upper and lower IGBT chips and the diode chip, which are recorded as Pa(t), Pb(t), Pc(t) and Pd(t) respectively; Step 5: Substitute the chip losses calculated in step 4 into the foster thermal resistance network model composed of the transient thermal resistance curve models of the IGBT chip and the diode chip, and calculate the junction temperature curve equation Tj(t) of each chip: ； Step 6: Obtain the maximum junction temperature Tjmax, average junction temperature Tjav and junction temperature fluctuation ΔTj of each chip under steady-state operating conditions through the Tj(t) curve equation. Comprehensively evaluate whether the IGBT module heat dissipation design is reasonable through the obtained maximum junction temperature Tjmax, average junction temperature Tjav and junction temperature fluctuation ΔTj.

2. The test method for simulating and calculating the junction temperature of the IGBT module in a energy storage converter according to claim 1, wherein: In the step 1, the position and method of pre-embedded thermocouple temperature measuring points of the IGBT module copper substrate are specifically to select the slot position of the IGBT module copper substrate, set the slot size according to the shape and size of the thermocouple, set the thermocouple pre-embedded position according to the slot size, fill the slot of the pre-embedded thermocouple with silver paste to fix it, smooth the surface of the silver paste until it is flush with the surface of the copper substrate, and then seal it with tape, and remove the tape after the silver paste is cured.

3. A test method for simulating and calculating the junction temperature of an IGBT module in a energy storage converter as claimed in claim 1, characterized in that: In step 3, the temperature of the copper substrate directly below the chip A, the chip B, the chip C and the chip D is directly obtained by pre-embedded thermocouples.

4. The test method for simulating and calculating the junction temperature of the IGBT module in the energy storage converter according to claim 1, wherein: In step 4, the power loss is simulated and calculated by using a simulation calculation tool provided by the IGBT module manufacturer or a self-built model.

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