An Averaged Discrete Circuit Model (ADCM) for a Single-phase Grid-connected Inverter

Simulation of low voltage distribution grid with many Single-phase Grid-connected Inverters (SGIs) is an important requirement for researchers and system planners. The paper presents an Averaged Discrete Circuit Model (ADCM) of the power stage an SGI. This proposed model achieves excellent accuracy at a fraction of the execution time compared to RealTime Switching (RTS) simulation model. The derivation of the discrete-time model for the SGI from the fundamental inverter equations is presented. The model is verified and compared with existing models for various practical scenarios such as grid-feeding inverter, active power filter, short circuit fault. A 27-bus radial LV distribution grid with 15 SGIs is used to verify the performance of the proposed model in a distribution network simulation. Time taken for simulation by the proposed model is orders of magnitude less compared to a RTS model with less than 0.1 % difference in accuracy compared to a conventional Voltage Controlled Voltage Source (VCVS) model.