Design and experimental investigation of digital model predictive current controller for single phase grid integrated photovoltaic systems

Abstract

Depletion of fossil fuel reserves has lead to identification of renewable sources of energy as alternative sources of energy for power generation. The photovoltaic plant is more prominent in present day scenario. The power electronic converters interfacing the photovoltaic generator with the grid gives rise to various power quality problems such as harmonics in current injected by the inverter into the grid and low output power factor. This paper focuses on the design, analysis and control of single phase grid integrated photovoltaic systems. In this paper a dual stage photovoltaic inverter system is simulated using MATLAB/SIMULINK software. A digital predictive current controller based on model predictive control theory with delay compensation technique is introduced for output current control of the single phase voltage source inverter integrating the photovoltaic generator with the grid. The proposed control strategy exhibits excellent steady state performance and attains a high output power factor. It also achieves very fast transient response during change in reactive power demands and grid voltage distortions. The efficacy of the proposed controller is validated by experimental implementation using low cost digital signal processor.