Title: Sensorless DC-link voltage regulation strategy for single-phase grid-connected solar photovoltaic systems

Authors: Raja Owais; Sheikh Javed Iqbal

Addresses: Electrical Engineering Department, National Institute of Technology Srinagar, Srinagar, J&K, India ' Electrical Engineering Department, National Institute of Technology Srinagar, Srinagar, J&K, India

Abstract: A sensorless DC-link voltage control technique is proposed for a two stage, single-phase grid-connected solar photovoltaic (PV) system. The developed control strategy is predicated on the fact that if PV power is directly fed into the grid, the DC link voltage would stabilise. However, losses must be properly compensated to maintain a flat DC-link voltage profile. To account for the system losses, teaching-learning-based optimisation (TLBO) is used offline. After the offline implementation, a regression model based on maximum power is built to estimate system losses. The regression model is applied to the system to predictively compensate for system losses. As a result, the DC link control loop is avoided, and sensorless control is achieved. A unit-template-based control is used to synchronise the PV system with the grid. Simulation experiments using MATLAB/Simulink are used to verify the superiority of the proposed scheme over the conventional sensor-based technique.

Keywords: photovoltaic; PV; senorless control; TLBO; hysteresis-current control; unit template; Lambert-W function.

DOI: 10.1504/IJMIC.2022.127100

International Journal of Modelling, Identification and Control, 2022 Vol.41 No.1/2, pp.133 - 142

Received: 20 May 2021
Accepted: 24 Nov 2021
Published online: 22 Nov 2022 *

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