Indian Journal of Science and Technology

Abstract

Objectives: To develop and analyze isolated photovoltaic based water pumping system employing Field Oriented Controlled (FOC) three-phase squirrel cage Induction Motor (IM) which in turn is used to run the centrifugal pump. To extract the maximum power from the solar panel during all conditions, Maximum Power Point Tracker (MPPT) has to be implemented. Method/Analysis: FOC-IM of 5th order differential equations have been solved using Runga Kutta Method for integration with dq axis in rotor reference frame in MATLAB/Simulink environment. The two MPPT techniques are based on calculations of the instantaneous values of the voltage and current of the PV cell. The Perturb and Observe (P&O) technique is based on the value of perturbation and the Incremental Conductance (INC) technique is implemented using the value of the Incremental Conductance. Findings: The power generation from various renewable energy sources is becoming popular because of greater efficiency and depletion of non renewable energy sources. In this paper, an isolated photovoltaic based model is considered which can be suitable for the remote areas where there is no grid connectivity. From the exhaustive study of literature, it is found that very few authors have worked on induction motor and that too employing FOC for PV based model. The characteristics of the Induction Motor are such that it draws high inrush current at starting. The peak power ratings of the inverters and converters depend on this starting current in such finite PV based sources. This ultimately leads to the high cost of the whole system. The analysis to this problem has not been discussed yet, which is an important concern in the field of PV based electric motor drives. This work is incorporated to achieve this objective. Novelty/Improvement: The whole developed model is analyzed using the two MPPT techniques viz Incremental Conductance and Perturb and Observe MPPT. The problem of starting current in the motor and the distortions in the torque deviations are highly dependent on the choice of MPPT. So keeping in view of the above two problems, the optimum MPPT technique has been stated in this work.

Keywords: Centrifugal Pump, Field Oriented Control (FOC), Incremental Conductance (INC), Induction Motor (IM), Maximum Power Point Technique (MPPT), Photovoltaic System (PV), Perturb and Observe (P&O)