Efficiency estimation on DPC active front-end rectifier loads for system-level transient studies

Many system-level studies involve the simulation of power systems with growing penetration of power electronic devices and loads at distribution level. This gives rise to the need for fast models of static switching converters and efficient simulation tools. The so-called dynamic average-value models (AVMs), which use averaging techniques by neglecting switching, are widely used and appear to be very promising for the system-level transient studies of power-electronic loads. However, considering converter losses and predicting the energy efficiency remains challenging. This paper presents a methodology to include converter losses in AVMs of medium power active front-end (AFE) rectifier loads. The proposed new method is applied to a two-level voltage source converter (VSC) operating under direct power control (DPC). The conducted simulation results demonstrate the new methodology and confirm its accuracy in predicting conduction and switching losses and efficiency, while providing significant computational savings compared to the detailed switching model.