Average-Value Model for Voltage-Source Converters With Direct Interfacing in EMTP-Type Solution
Seyyedmilad Ebrahimi, Juri Jatskevich
Abstract
Average-value models (AVMs) of high-frequency switching voltage-source converters (VSCs) are indispensable for fast/efficient simulation of VSC-based power systems. However, in EMT/EMTP-type programs large simulation time-steps cannot be utilized with conventional non-iterative interfacings of AVMs due to numerical inaccuracy/instability as a result of a one-time-step interfacing delay. In this letter, a directly-interfaced AVM has been developed for the VSCs which eliminates the interfacing delay and allows large time-steps. This is achieved by formulating the AVM in the nodal form that is solved simultaneously with the overall network nodal equations. The new proposed model is demonstrated to outperform the existing AVMs of VSCs in terms of accuracy at fairly large time steps.