Nonlinear Observer Based on Linear Matrix Inequalities for Sensorless Grid-tied Single-stage Photovoltaic System

• Main Authors: TERAN-GONZALEZ, R. A. J., PEREZ, J., BERISTAIN, J. A.
• Format: Article
• Language: English
• Published: Stefan cel Mare University of Suceava 2021-08-01
• Series: Advances in Electrical and Computer Engineering
• Subjects: dc-ac power converters; maximum power point trackers; linear matrix inequalities; observers; takagi-sugeno model
• Online Access: http://dx.doi.org/10.4316/AECE.2021.03011
• ISSN: 1582-7445; 1844-7600

The objective of this work is to design a Nonlinear Observer used in a Cascade Control scheme for Maximum Power Point Tracking goals of a grid-tied single-phase photovoltaic inverter. The main contribution of this work is to employ a nonlinear observer to reduce the number of sensors of an AC-grid-tied single-stage PV system. The nonlinear observer design was developed using the Takagi-Sugeno PV system model and Linear Matrix Inequalities based on Lyapunov stability criteria. To validate the performance of the nonlinear observer-based cascade control, the results of a comparison between the PV system with observer (without DC voltage sensor) and a PV system with DC voltage sensor (without observer) are presented. A suitable PV power estimation with the nonlinear observer-based cascade control is achieved, which allowing a good performance of the MPPT algorithms. Perturb & Observe and Incremental Conductance MPPT algorithms were used.