How to use a multimeter to measure igbt module
First, determine the polarity
First of all, the multimeter dialed in R × 1K block, measured with a multimeter, if a pole and the other two poles of the resistance to infinity, after switching pens the pole and the other two poles of the resistance 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, after switching the pen to measure the resistance value is smaller. In the measurement of the resistance value is small in a time, the judgment of the red pen connected to the collector (C); black pen connected to the emitter (E).
Second, to determine the good and bad
The multimeter will be dialed in the R × 10K block, with the black pen to the collector of the IGBT (C), the red pen 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 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 dialed in the R×10K block, because the internal battery voltage of the multimeter below the R×1K block is too low to 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).
Inverter IGBT module detection:
Dial the digital multimeter to the diode test file, test the diode characteristics of the IGBT module between c1 e1, c2 e2 and the forward and reverse diode characteristics 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 of the U, V, W phase of the wire removal, the use of diode test gear, the red pen connected to the P (collector c1), the black pen in order to measure the U, V, W, the multimeter displays the value of the maximum; will be reversed, the black pen connected to the P, the red pen to measure the U, V, W, the multimeter displays the value of 400 or so. 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 the maximum. The positive and negative 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 the breakdown of the short-circuit situation.
Red and black pens were measured between the gate G and the emitter E positive and negative characteristics of 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.
