Open AccessInvestigation of three‐level NPC‐q Z S inverter‐based grid‐connected renewable energy system
Author(s) -
Singh Nagendra,
Jain Sanjay K.
Publication year - 2020
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2019.0731
Subject(s) - control theory (sociology) , controller (irrigation) , inverter , integrator , capacitor , renewable energy , harmonics , voltage , grid , engineering , computer science , electrical engineering , control (management) , mathematics , geometry , artificial intelligence , agronomy , biology
The neutral point clamped quasi‐ Z ‐source (NPC‐qZS) inverter is poised to become a potential candidate for renewable energy applications because it yields a continuous input current and voltage boost. In this study, the closed‐loop control of grid‐tied three‐phase (3‐ ϕ ) NPC‐qZS inverter, fed with renewable energy sources, is proposed for the first time. A dynamic model has been developed to accurately design the control strategy. The proposed strategy includes the control of grid‐tied current and the peak dc‐link voltage (PDV). The control of grid‐tied current is achieved through a damped‐second‐order‐generalised integrator. The PDV is estimated indirectly from the voltages of qZS network capacitors and is regulated by an integral‐double‐lead controller. Two modified modulation techniques based on phase‐opposite disposition and in‐phase disposition are proposed to yield shoot through by injecting 3rd harmonics for maximum constant boost control. A comparison is drawn between the performance of the proposed controller and sliding‐mode controller on the dc side. The controller design and system performance are validated through real‐time simulation and experimentation on a practical setup in the laboratory.