A Comprehensive Analysis of a Digital Control Strategy for Photovoltaic-Based Single-Phase Grid-Tied Inverter Systems

This paper presents the design of a single-phase grid-tied solar inverter and its control system. It investigates the system’s behavior to optimize its performance. The power section consists of a DC-DC converter followed by an inverter with filters. The control system includes algorithms for maximum power point tracking (MPPT), phase locking (PLL), current shaping for grid injection, and DC link voltage regulation. A systematic procedure is proposed to simulate and implement compensators for the control system on a digital microcontroller. The paper further details the implementation of the control strategy on an experimental prototype. This prototype utilizes a proportional-resonance controller with harmonic compensators, achieving a highly desirable grid current profile with significantly reduced harmonics compared to existing similar products.
Finally, the paper presents simulation results of a photovoltaic system with a boost converter, a Highly Efficient and Reliable Inverter Concept (HERIC) inverter, and its compensators, operating at 20 kHz switching frequency.

Author: Soheil Hasani Sangaani

IEEE paper for “32^th International Conference on Electrical Engineering”