Realizable Reference Antiwindup Implementation for Parallel Controller Structures

Parallel controller structures are often used for the control of harmonic components in those power converters, including harmonic-compensation functions. The controlled signal can be distorted during the voltage saturation of the power converter output. This article proposes an implementation of the realizable reference antiwindup technique suitable for parallel controllers in multiple reference frames. The proposed implementation is simple and does not require a particular type of controllers nor special controller arrangements. The proposed implementation can be used for any kind of linear controller structure regardless of the variables being controlled. In the context of harmonic current controllers, the antiwindup implementation allows separating the harmonic controller outputs for canceling or decreasing them during steady-state saturation to improve the waveform quality. Different saturation options are analyzed for the inner loop current controller of grid-forming converter applications.