Modelling of voltage source inverter based DVR

Modelling of a voltage source inverter based DVR is presented in this paper. Two mathematical functions are proposed to benefit the design of controller and for simulation work; preparation for quick simulation instead of using physical models. An averaging operator is applied to the switching model of the inverter, and then the averaged functions are all perturbed using linearization technique. The process is the key for deriving a small signal model. The primary model in stationary a-b-c reference frame is Park´s transformed to be the model in a synchronously rotating d-q frame of reference. Model verification was carried out comparatively with the standard physical model implemented in MatLab; transient responses of the voltage and current were used to illustrate the resulting models´ accuracy. Owing to the results, it can be guaranteed that the proposed model is a more precise model; only a slight discrepancy is found on the responses, envisaging the potential use of the models.