How to use a multimeter for the measurement of an igbt module
First, judge the polarity
First of all, the multimeter dialled in the R × 1K block, measured with a multimeter, if a pole and the other two poles of the resistance value is infinity, switch the pen after the pole and the other two poles of the resistance value is still infinity, it is judged that this pole is the gate (G). The rest of the two poles and then measured with a multimeter, if the measured resistance value is infinity, switch the pen after the measurement of the resistance value is smaller. In the measurement of the resistance value of a smaller one, then judge the red pen connected to the collector (C); black pen connected to the emitter (E).
Second, judge the good and bad
The multimeter will be dialled in the R × 10K block, with the black pen connected to the collector of the IGBT (C), the red pen connected to the emitter of the IGBT (E), this time the multimeter pointer in the zero position. Touch the gate (G) and collector (C) with your finger at the same time, then the IGBT is triggered to conduct, the multimeter's pointer swings to the direction of the smaller resistance value, and can stand to indicate a certain position. Then touch the finger at the same time the gate (G) and the emitter (E), then the IGBT is blocked, the multimeter's pointer back to zero. At this point you can judge 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 dialled in R×10K block, because the internal battery voltage of the multimeter is too low in the following gears of the R×1K block, which can not make the IGBT conductive when detecting the good or bad, and it is not possible to judge the good or bad of the IGBT. 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 the diode test gear, test the diode characteristics of the IGBT module between c1 e1, c2 e2 as well as the forward and reverse diode characteristics between gate G and e1, e2 to judge whether the IGBT module is intact or not.
Take the six-phase module as an example. The load side of the U, V, W phase wire removal, the use of diode test gear, the red pen connected to the P (collector c1), the black pen sequentially measured U, V, W, the multimeter shows the value of the largest; will be reversed, the black pen connected to the P, the red pen to measure the U, V, W, the multimeter shows the value of about 400. Then connect the red pen to N (emitter e2), the black pen to measure U, V, W, the multimeter shows the value of about 400; black pen to P, red pen to measure U, V, W, the multimeter shows the value of maximum. The positive and negative characteristics between the phases should be the same, if there is a difference between the IGBT module performance deterioration, should be replaced.IGBT module damage, only the breakdown of the short-circuit situation.
Red and black pens were measured between the gate G and emitter E positive and negative characteristics, the multimeter two measured values are the largest, then it can be determined that the IGBT module gate is normal. If there is a numerical display, the gate performance deterioration, the module should be replaced. When the positive and negative test results are zero, indicating that the detection of a phase of the gate pole has been short-circuited. When the gate is damaged, the voltage regulator of the circuit board to protect the gate will also be damaged.
