Centralised model‐predictive decoupled active–reactive power control for three‐level neutral point clamped photovoltaic inverter with preference selective index‐based objective prioritisation. Issue 4 (1st April 2019)

• Record Type: Journal Article
• Authors: Bonala, Anil Kumar; Sandepudi, Srinivasa Rao
• Is Part Of: IET power electronics. Volume 12:Issue 4(2019)
• Page Start: 840
• Page End: 851
• Publication Date: 2019-04-01
• Subjects: reactive power control -- invertors -- photovoltaic power systems -- electric current control -- power grids -- voltage control -- optimal control -- predictive control -- PI control; centralised model‐predictive -- three‐level neutral point -- photovoltaic inverter -- preference selective index‐based objective prioritisation -- single‐stage grid‐tied three‐level -- centralised model predictive control -- CMPC -- maximum power extraction -- active–reactive power tracking -- single objective function -- reactive power exchange -- preference selective index‐based dynamic weighting factor selection approach -- control approach -- optimal control action -- steady‐state -- dynamic tracking performance -- control objectives -- classical proportional–integral‐based model predictive control -- DC‐link capacitor voltage balancing -- DC‐link voltage regulation -- decoupled active‐reactive power control -- DC‐link voltage control loop; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2018.5825
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : This study presents a single‐stage grid‐tied three‐level neutral point clamped photovoltaic inverter with a centralised model‐predictive decoupled active–reactive power control. The proposed centralised model predictive control (CMPC) incorporates the constraints of maximum power extraction, dc‐link capacitor voltage balancing and active–reactive power tracking in a single objective function. The dc‐link voltage of the inverter is regulated to its reference for extracting the maximum power. In order to eliminate the impact of reactive power exchange on floating dc‐link voltage regulation, a decoupled active–reactive power control is used in the CMPC. Furthermore, a preference selective index‐based dynamic weighting factor selection approach is introduced to maintain the relative importance between the power tracking and dc‐link capacitor voltage balancing. The proposed control approach eliminates the outer dc‐link voltage control loop and also, the empirical approach required for the selection of weighting factors. As a result, it ensures an optimal control action in each sampling period to improve the steady‐state and dynamic tracking performance of the control objectives. The proposed control approach is experimentally verified by using a 1.2 kW laboratory‐scale prototype and the results are presented to demonstrate its effectiveness compared to the classical proportional–integral‐based model predictive control.