Ig module is damaged due to poor heat dissipation The frequency converter makes a sudden sound during operation, and the external connection is burned. It is found that the IGBT module of the frequency converter is damaged after disassembly. Through the test of relevant boards, it is found that the IGBT trigger circuit is damaged, and other plates are normal. When removing the frequency converter board, it was found that there were a lot of oil and dust on the power board and current detection board. Turn on the fan of the heat sink of the frequency converter and see that the heat sink is also covered with oil and sundries, which completely blocks the heat dissipation channel of the frequency converter. It is inferred that the Ig module of the frequency converter is damaged due to poor heat dissipation. Maintenance process: first, completely disassemble the frequency converter, remove the heat sink of the heat dissipation channel, clean the heat sink with air pressure gas, and clean all the internal structural parts and boards of the frequency converter. Install the IGBT module. When installing the IGBT module, install it in sequence according to the requirements of the module, with appropriate torque. Repair the trigger circuit, and then install other devices in turn. After installation, conduct static test. After the static test results are good, conduct power on test and load test. The on load test is qualified and the maintenance is completed successfully. Experience summary: Based on the maintenance of several frequency converters in different models and different use environments, it is concluded that the main reason for the damage of frequency converter IGBT module is the poor use environment, which leads to the damage of electronic components on gate drive card and the blockage of heat dissipation channel of frequency converter* The easily damaged devices are voltage stabilizing tube and optocoupler. Check whether there is a problem in the driving circuit. Compare whether the resistance of each trigger terminal is consistent when power is off. The voltage waveform at the trigger end can be measured after power on. However, some frequency converters cannot be started without being installed into the module. At this time, a false load is connected in series at the p-end of the module to prevent the module from being burnt out due to touching the originator or other lines by mistake during inspection.