Power Factor Improvement and MPPT of the Grid-Connected Solar Photovoltaic System Using Nonlinear Integral Backstepping Controller

The power generated by solar photovoltaic cells (SPVC) depends on environmental conditions and is intermittent. Furthermore, a standalone solar system is not suitable for continuously powering an active load. In this study, a single-phase grid-tied solar hybrid system with intelligent power-sharing capability is proposed. Maximum power point tracking (MPPT) algorithm is applied to extract maximum power from the solar photovoltaic (SPV) array with a nonlinear induction motor (IM) connected as a load. Nonlinear load at output reduces the power factor of the system; therefore, the power factor correction (PFC) circuit is designed to maintain a power factor (PF) nearly equal to unity. A model of the non-inverting boost converter is also designed in this work. A nonlinear controller with integral backstepping (IBS) is proposed in this work for MPPT of the SPV array with simultaneous power factor improvement. The control of IM connected with the voltage source inverter is achieved by using the voltage/frequency (V/F) technique. The proposed PFC controller and the MPPT technique are compared with a conventional proportional-integral (PI) controller. Simulation results demonstrate that by using an IBS controller the PF of the system is improved to 99.2%; hence, the proposed controller is more robust and efficient. This controller also reduced the system's total harmonic distortion to 1%. The proposed techniques are implemented in MATLAB/SIMULINK to validate the results.

Automated summary

This study proposes a single-phase grid-tied solar hybrid system with intelligent power-sharing capability, which extracts maximum power using maximum power point tracking algorithm and improves the power factor through a nonlinear controller. Simulation results demonstrate that the proposed control techniques achieve good performance in improving system efficiency and reducing harmonic distortion.