Control Strategy Based on Associative Memory Networks for a Grid-Side Converter in On-Grid Renewable Generation Systems Under Generalized Unbalanced Grid Voltage Conditions

Abstract

This paper presents a control strategy based on Associative Memory Networks (AMN) for controlling a grid-side converter in the On-grid renewable generation systems under generalized unbalanced grid voltage conditions. In the proposed scheme, the controller operates in a rotating synchronous reference frame, where standard PI controllers are utilized in the fast inner dual current loops to track the current references, while in the outer loop, the AMN is used as a nonlinear adaptive integrator combined with a simple proportional controller for the DC link voltage regulation. By using the simulation study, it is shown that the overshoot of the proposed control system in transient state is lower compared with that of the optimal PI controller. Consequently the overvoltage of the DC link capacitor due to abrupt changes of the active power generated by renewable generation systems under both balanced and unbalanced grid voltage conditions could be effectively avoided.