Large Time-Scale Electro-Thermal Simulation Model of Inverter Power Module for Hybrid Vehicle Applications

摘要

A novel electro-thermal decoupled approach for large time-scale electro-thermal simulation of inverter power module (IPM) used to drive a Permanent Magnet Synchronous Motor (PMSM) is presented in this paper. The key assumption made here is that the inverter drive system electrical performance is not affected by the temperature of the semiconductor power devices; this allows the electrical and thermal simulations to be decoupled. Based on this strategy, the electro-thermal simulation of the inverter power module is divided into two phases: (1) Initially, the overall electrical simulation of the inverter drive system in continuous time domain and (2) PWM switching signal based power losses calculation and the thermal simulation of the inverter power module. The features of this method is that the PWM switching signal is reconstructed using continuous smooth time-domain motor voltages obtained from phase (1), so that the accurate power losses calculation and thermal simulation can be carried out using continuous smooth electrical waveforms. In this way, the conventional approach where devices are represented by switches is avoided and the electrical-thermal simulation can be carried out using relatively large simulation time steps, which allows a significant speed-up of the simulation. Simulation of over 10 minutes of real time operation has been carried out; the total simulation is of the order of 1hr CPU time for a 3.12 GHz CPU 1 Gbyte memory PC.