A novel particle swarm optimization based plant-in-loop tuning method for PI controller of integrated power converters

Abstract

Integrated Power Converters such as Shunt Active Power Filters (APFs), when integrated with renewable sources like solar PV, offer a more capable and cost-effective solution for both their core function and for feeding the renewable power to the grid. Shunt APF is generally integrated with PV arrays on the common DC link to compensate for power quality issues and feed solar PV power simultaneously. However, the regulation of the DC link, which is the foundation of the operation of such converters, can be more challenging due to the inclusion of PV intermittency. So, the PI controller, mostly used for DC link regulation, should be tuned optimally considering the variable operating conditions. Most tuning methods, whether offline or online, rely on mathematical modeling of the converter and are affected by inherent inaccuracies. Therefore, this work proposes an in-plant PI tuning method for shunt APF, which doesn’t require mathematical modeling and can be implemented in realtime within the actual plant and operating conditions therein. The method tunes the PI controller without having to relax the limits on its output, which are required for the safety of the hardware. The proposed method has been validated using realtime simulation and hardware setup of the PV-integrated shunt APF, and, in both cases, the method shows superior performance in regulating the DC link voltage of the integrated converter system under various operating conditions.