Exact Grid Side Current Control Modeling for a Medium Voltage Wind Farm

The low switching frequency of medium voltage drives requires an accurate current control model to design the controller, as delays and discretization process are no longer negligible. In addition, the grid impedance and the feed-forward voltage also affect the response of the system. This paper presents a procedure that exactly models the current control loop of a medium voltage wind farm. The modeling procedure is experimentally validated. An exact current control model allows the designer to tune the controller and analyze the stability of a wind farm under different circumstances, such as different grid short circuit ratios (SCR) with a high reliability. The differences with the experimental results will only be limited to deviations between the impedances of the model and real plant.