Study On Temperature Impact For IGBT Power Module In Three-phase Inverter System

The defeats of IGBT(Insulated Gate Bipolar Transistor) power module, due to long-term accumulated heat and power, vary from one to another. The difference of degradation degree and direction may lead to imbalance in temperature, so as to accelerate the deterioration of electrical property. As a key unit of the power conversion system, IGBT has an important effect on the stability of whole system. As such, it is of significance to research on the relation between thermal property and electrical property and the working experiment about the IGBT module.In order to control and inspect electrical parameters and thermal property of IGBT module, this research designs a three-phase inverter test system of which the electrical parameters are adjustable, as well as temperature control and collection system.First of all, build a model to calculate the mean power of IGBT module, mine the key parameters that affect the thermal property(such as collector-to-emitter voltage, collector current, switching frequency and drive dead time), verify and analyze the selected parameters via the single pulse incubator testing, electrical heat stress testing and finite element simulation analysis(ANSYS). This provides a direction for the design of the three-phase inverter test system. And then, design and conduct a three-phase adjustable inverter test system, combined with DDS(Direct Digital Synthesis) and FPGA(Field Programmable logic Array), developed the IGBT gate driving system of three-phase inverter circuit, so as to control the switching frequency and drive dead-time of IGBT module. In addition, design and build a model which can collect the junction temperature and case temperature in real time, meanwhile conduct a temperature shock test with an adjustable upper bound and lower bound case temperature. Finally, data processing is needed to figure out the relationships between collector current and module temperature,switching frequency and module temperature, junction temperature and case temperature,power consumption and case temperature, drive dead time and case temperature. Results indicate that the testing model can control the key parameters of IGBT module, collect and control the junction temperature and case temperature, so it can provide accurate and sufficient data to the research of relationship between electrical parameters and module temperature in inverter test system, as well as the relationship between electrical parameters and junction allowance in practice.