In Power cycling test, for low-voltage and low-power modules, it is generally considered that the saturation voltage drop VCE(sat) reaches 105% of the initial value or the thermal resistance Rth reaches 120% of the initial value as the basis for judging the failure of the IGBT module. However, since the high-voltage and high-power IGBT modules are connected in parallel with multiple chips, there are differences in the aging speed of the chips, and the degradation of individual chips has little influence on the parameters of the entire module, so the failure judgment standard may not be applicable. In order to obtain the degradation of the characteristic parameters of the high-voltage and high-power IGBT module in the power cycle test, this paper selects the 6500V/600A IGBT module as the research object, adopts the experimental method of constant junction temperature fluctuation, and tests the module parameters after every cycle 20,000 times until the module fails. Three failure modes were found through the test: GE failure, CE failure, GE and CE failure. And the degradation law of the parameters of the high-voltage and high-power IGBT module during the power cycling test was obtained.

To reduce costs and obtain excellent performance, acrylic modified lignin sulfonate instead of butyl methacrylate stearyl methacrylate was prepared to oil absorption resin. And 1, 4-butylene glycol dimethacrylate as a crosslinking agent, 2,2’-azo-bis-(2-methylpropionitrile) as the initiator, with butyl acrylate to product the high lignin oil-absorbing resin, selected the best scheme for preparing by the orthogonal method, and the different concentrations of lignin and the best resin properties determined by SEM and its oil absorption test. Experimental results show that the resin has the high oil absorption properties,the maximum absorption of 20 times, and the suction speed is fast that 90min to reach saturation; It also has other characteristics,such as inexpensive cost, lightweight, easy recycling and disposal, reusable and so on.