Power Loss Calculation Method of Intermediate 60° SPWM Modulation in Two-Level Inverter

For the intermediate 60° SPWM modulation widely used by two-level inverter in rail transit industry, the operating characteristics of IGBT devices under traction and electric braking conditions are analyzed respectively, and the analytical expressions of on-state loss and switching loss under two conditions are derived. Test results of a locomotive inverter are presented, and deviation analysis shows that the method proposed in this paper has high accuracy. The total loss deviation ratio of IGBT device is within ±5.4%. It provides a very simple power loss calculation form of intermediate 60° SPWM modulation for product design and reliability study of IGBT devices in two-level inverter.