Junction Temperature Balancing Strategy for Parallel Insulated Gate Bipolar Transistors Based on Thermal Resistance and Gate Resistance Compensation

The problem of a gradual increase in the capacity of the magnetic confinement power supply in a tokamak device is effectively solved with insulated gate bipolar transistor (IGBT) parallel connections. The steady-state junction temperature balance (SSJTB) is one of the key factors for the safe and stable operation of parallel IGBTs. Therefore, it is crucial to improve the stability of parallel IGBTs by investigating the steady-state junction temperature difference (SSJTD) of parallel IGBTs under thermal resistance mismatch.

However, the existing methods focus mainly on modeling the IGBT thermal network or single thermal resistance matching. These results do not analyze the matching strategy between the thermal resistance and the gate resistance. The research in this paper found that the gate resistance and thermal resistance parameters affect the SSJTD of parallel IGBTs. In the case of thermal resistance parameter mismatch due to inconsistent heat dissipation conditions, there exists a reasonable gate resistance parameter that allows the parallel IGBTs to reduce the SSJTD under the total influence of both.

Therefore, a SSJTD model was created to analyze and calculate the equilibrium point. The simulation results showed that the parameter compensation scheme can effectively reduce the SSJTD between the parallel IGBTs, which can guide the junction temperature equalization strategy of the parallel IGBTs and can also be used as the basis for the parameter adjustment of the active gate drive.