A novel current controller in photovoltaic grid-connected inverter. (3rd April 2021)

• Record Type: Journal Article
• Authors: Mao, Peng; Zhang, Mao; Zhu, Yaru; Zhang, Weiping
• Is Part Of: Journal of the Chinese Institute of Engineers. Volume 44:Number 3(2021)
• Page Start: 277
• Page End: 292
• Publication Date: 2021-04-03
• Subjects: Grid-connected inverter -- proportional and resonant (PR) controller -- resonant-proportional (R-P) controller -- resonant-proportional and resonant-proportional (RP-RP) controller; Technology -- Periodicals; Engineering -- Periodicals; 620.005
• DOI: 10.1080/02533839.2021.1884604
• Languages: English
• ISSNs: 0253-3839

Abstract

ABSTRACT: Current control technology is a key issue in photovoltaic grid-connected inverters. Usually, since proportional resonant (PR) control can achieve infinite gain at a certain frequency leading to zero stationary error and selective disturbance rejection as compared with PI controller, it is widely used in grid-connected inverters. In this paper, performance of system using PR controller is investigated first. The disadvantages of PR controller are as follows: (1) the disturbance introduced by voltage loop has a severe impact on quality of grid-connected current; (2) Phased Locking Loop (PLL) is essential in system. Based on degree of freedom theory, resonant-proportional (R-P) controller and resonant-proportional and resonant-proportional (RP-RP) controller are proposed to overcome the disadvantages of PR controller. Additional advantages of RP-RP controller are as follows: (1) less impact on quality of grid-connected current caused by voltage loop disturbance; (2) non-essential PLL; (3) better immunity to fluctuation of grid frequency. A detailed comparison of different controllers is also obtained. Simulation and experiment results verify the prototype's feasibility and validity.