When the inverter is facing abnormal working conditions, take shutdown or other protective measures to protect the safety of the IGBT module as much as possible. What factors will affect or even jeopardize the safety of IGBT modules?
1. Voltage factor (1) When the power supply voltage of the IGBT module is too high, it will exceed its safe working range, causing its breakdown damage;
(2) When the power supply voltage is too low, the load capacity is insufficient, the running current is increased, and the running motor is prone to stalling, which jeopardizes the safety of the IGBT module;
(3) The fluctuation of the power supply voltage, such as the loss of capacity of the DC loop filter (storage energy) capacitor, can cause the generation of surge current and spike voltage, which poses a threat to the safe operation of the IGBT module;
(4) Control voltage of IGBT - When the driving voltage is low, it will cause under-excitation of IGBT, the internal resistance of conduction will become large, power consumption and temperature rise, and it is easy to damage IGBT module.
2. Current factor (1) Overcurrent, in the light and medium overcurrent state, is the inverse time protection area;
(2) Severe overcurrent or short circuit condition, no delay and quick break protection;
3, temperature factors (1) mild temperature rise, the use of forced air cooling and other means;
(2) When the temperature rises to a certain amplitude, the shutdown protection;
4, other factors (1) the abnormality of the drive circuit, such as the interruption of the negative cut-off negative pressure control loop, etc., will cause the IGBT to be accidentally touched and damaged;
(2) The control circuit and the detection circuit itself are abnormal. For example, the reference voltage of the detection circuit drifts, which causes the protection action to change from the control point, and does not have the protection effect as it should.
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