Average-Value Modeling of Voltage-Source Inverters with Parametric Losses for AC Machine Drives

AC machine drives with voltage-source inverters (VSIs) are extensively utilized in various applications. Average-value models (AVMs) of VSIs are used to facilitate fast and efficient simulations of such systems in electromagnetic transient (EMT) programs. However, the conventional existing AVMs do not consider losses in VSI operation. This paper presents a methodology to implement a lossy AVM (LAVM) and proposes three equivalent circuits for possible implementation. The LAVM considers conduction and switching losses, which also depend on operating conditions such as frequency and current. Depending on the LAVM interfacing needs, the losses may be implemented on the DC-side, AC-side, or split between DC and AC sides. The proposed methodology is demonstrated on an induction motor drive for which the losses are extracted experimentally and then fitted into the LAVMs. The proposed LAVM is shown to improve the accuracy of capturing the losses compared to the conventional detailed switching model and AVM of VSI driving the induction motor over a wide range of operating conditions.