Simulation of Efficient MPPT Algorithm under Partial Shading Condition for Boost Converter System

Abstract: The Perturb & Observe (P&O) algorithms are widely used in control of MPPT due to their simple structure and reduced number of necessary measured parameters. This algorithm has the drawback that after reaching the maximum power point its starts deviating continuously all the time resulting in substantial amount of power loss at maximum power point. Although this algorithm is quite simple to implement and requires only one voltage sensor, the cost of implementation of this algorithm is low. On the other hand the Incremental Conductance(IC) method has the advantage over the Perturb & Observe as it does not oscillate around the maximum power point under rapidly varying environmental conditions. The disadvantage of the Perturb and observe method to track the peak power under fast varying atmospheric condition is overcome by INC method. The INC can determine that the MPPT has reached the MPP and stop perturbing the operating point. If this condition is not met, the direction in which the MPPT operating point must be perturbed can be calculated using the relationship between dl/dV and –I/V Increment size determines how fast maximum power point is tracked. Fast tracking can be achieved with bigger increments but the system might not operate exactly at the maximum power point and oscillate about instead. This method has complex circuitry, accuracy of the method depends on the iteration size, which is usually fixed for the conventional incremental conductance method. In this paper the proposed scanning MPPT adjusts the duty cycle corresponding to the global maxima. The power obtained from the proposed controller is higher and non-oscillatory around the MPP compared to P&O and INC controllers which fails under partial shading condition when multiple peaks come into play. The scanning technique algorithm determines the maximum power delivering capacity of the panel at a given operating condition and controls the PCU to extract the same from the PV panel.

Keywords: PV Panel, MPP, Boost converter, VSI & SPWM.