Accurate calculation of losses incurred in the power electronics converter is particularly essential in selection of devices and optimal thermal design. Conduction losses are mainly dependent on the currents flowing through the device. This article attempts to devise device current expressions in a space vector modulated (SVM) voltage source inverter (VSI). Emphasis is laid on deriving the equations which facilitate for quick and accurate calculation of conduction losses in the converter at different load conditions. Importance of the proposed work also lies in providing a generic way of mathematical modelling of device currents in complex pulse-width modulation (PWM) schemes. Initially, device currents in  SVM inverter without considering dead-time was presented, where a generalized expression for offset voltage is derived. As dead-time is absolutely essential for safe operation of devices, effect of dead-time consideration on device currents is discussed. Finally, as channel of MOSFETs can conduct bidirectionally, the device currents considering reverse conduction of MOSFETs is presented. Simulation analysis is performed using MATLAB/SIMULINK®. The effectiveness of the derived expressions is also validated experimentally using 415 V, 5 kW SiC MOSFET based voltage source inverter setup.

Power losses are of significant importance for the design of converter. Conduction losses are mainly dependent on the currents flowing through the device. Owing to high switching frequency, device currents are quite complex. This paper presents with closed form solution for device currents in a space-vector modulated inverter. Initially, it discusses the considerations which need to be taken for deriving modulating equations of switches, and then formulates device currents. These equations facilitate for quick calculation of conduction losses in the converter at different load conditions.