With the increasing popularity of high-power power supply equipment, the role of IGBT in high-power power supply equipment is becoming more and more important, so it is necessary to have a full understanding of IGBT knowledge.
As the frequency of use increases, IGBTs will inevitably be damaged in the process of use, so developers need to identify them quickly and accurately, and this article will tell you the way to quickly identify whether IGBTs are damaged from several aspects.
Judgment of polarity
First of all, dial the multimeter in R × 1KΩ block, measured with the multimeter, if a pole and the other two poles resistance value is infinity, after switching the meter pen the pole and the other two poles resistance value is still infinity, then determine the pole is the gate (G). The remaining two poles then measured with a multimeter, if the measured resistance value is infinity, the resistance value is smaller after switching the meter. In the measurement of a smaller resistance value, the red pen is judged to be connected to the collector (C); the black pen is connected to the emitter (E).
Judgment of good or bad
Set the multimeter to R×10KΩ, connect the collector (C) of IGBT with the black meter pen and the emitter (E) of IGBT with the red meter pen, and the pointer of the multimeter is at the zero position. Touch the gate (G) and collector (C) with your finger at the same time, when the IGBT is triggered to conduct, the pointer of the multimeter swings to the direction of smaller resistance and can stand in a certain position. Then touch the gate (G) and emitter (E) with your finger at the same time, when the IGBT is blocked and the pointer of the multimeter returns to zero. At this point, you can judge that the IGBT is good.
Any pointer multimeter can be used to test IGBT.
Note that when judging the IGBT good or bad, the multimeter must be dialed in R × 10KΩ block, because R × 1KΩ block below the internal battery voltage of the multimeter is too low to detect the IGBT good or bad, and can not make the IGBT conductive, and can not determine the IGBT good or bad. This method can also be used to detect the power field effect transistor (P-MOSFET) good or bad.
Inverter IGBT module detection
Set the digital multimeter to diode test gear and test the positive and negative diode characteristics between IGBT module c1e1, c2e2 and between gate G and e1, e2 to determine whether the IGBT module is intact.
Take the six-phase module as an example. The load side U, V, W phase wire removal, use the diode test file, the red meter pen connected to P (collector c1), the black meter pen in turn to measure U, V, W, the multimeter shows the maximum value; will be reversed, the black meter pen connected to P, the red meter pen to measure U, V, W, the multimeter shows a value of about 400. Then the red meter pen connected to N (emitter e2), the black meter pen to measure U, V, W, the multimeter shows the value of about 400; the black meter pen connected to P, the red meter pen to measure U, V, W, the multimeter shows the value of the maximum. The forward and reverse characteristics of each phase should be the same, if there is a difference between the IGBT module performance deterioration, should be replaced. IGBT module damage, only breakdown short circuit situation.
The red and black pens should measure the forward and reverse characteristics between the gate G and the emitter E. If the value measured by the multimeter twice is the maximum, it can be judged that the gate of the IGBT module is normal. If the value is displayed, the gate performance becomes poor and the module should be replaced. When the forward and reverse test result is zero, it means that the gate of the detected phase has been short-circuited by breakdown. When the gate is damaged, the voltage regulator of the circuit board to protect the gate will also be broken down and damaged.
When there is a problem with IGBT, you can make your own judgment according to the situation given in the text, which can help you save a lot of time and cost. If you have not yet encountered IGBT problems, you can also collect this article first, so that you can easily consult it when you encounter problems.
