Design and Experimental Implementation of a Hysteresis Algorithm to Optimize the Maximum Power Point Extracted from a Photovoltaic System

Abstract

In the several last years, numerous Maximum Power Point Tracking (MPPT) methods for photovoltaic (PV) systems have been proposed. An MPPT strategy is necessary to ensure the maximum power efficiency provided to the load from a PV module that is subject to external environmental perturbations such as radiance, temperature and partial shading. In this paper, a new MPPT technique is presented. Our approach has the novelty that it is a MPPT algorithm with a dynamic hysteresis model incorporated. One of the most cited Maximum Power Point Tracking methods is the Perturb and Observer algorithm since it is easily implemented. A comparison between the approach presented in this paper and the known Perturb and Observer method is evaluated. Moreover, a new PV-system platform was properly designed by employing low cost electronics, which may serve as an academical platform for further research and developments. This platform is used to show that the proposed algorithm is more efficient than the standard Perturb and Observer method.

Numerical Experimental Validation of a Proposed MPPT Algorithm with Dynamic Hysteresis for PV Systems

“…1, R sh is the shunt resistance, R s is the serial resistance, I P V , I d , I sh and I ph are the PV array output current, the current through the diode, the current in parallel resistance and the current generated by the sun incident light, respectively. Finally, V P V is the PV module output voltage [15], [28], [29].…”

“…where µ sc is the temperature coefficient of the short circuit current, G is the irradiation effect, G stc is the irradiation effect in specific operating conditions (defined as standard conditions [29]), and I sc,ref is the short circuit current at a given reference temperature. On the other hand, the saturation current is given by [23]:…”

“…The conversion stage in photovoltaic systems is necessary to provide quality energy with the characteristics required by the load. Besides, this stage allows to overcome the undesired effects on the output PV power imposed by the environmental perturbations, and to achieve, as well as possible the maximum power point [12], [29]. This maximum power production is based on the adjustment of the load, through the conversion stage, seen by the PV panel, which is subjected to the mentioned non-uniform environmental conditions.…”

“…In addition to the PV panel and the MPPT algorithm, a photovoltaic system also requires a suitable power conversion stage between the terminals of the PV panel and the user load [11], [23]. For applications that require DC energy, the conversion stage is realized by a DC/DC converter, which manipulates the load seen by the PV panel when its duty cycle is modified through the MPPT algorithm [29]. Hence, the maximum power point is adapted to the PV conditions, while the converter output keeps up the voltage and the current levels according to the load requirements [13], [23], [29], [30].…”

“…For applications that require DC energy, the conversion stage is realized by a DC/DC converter, which manipulates the load seen by the PV panel when its duty cycle is modified through the MPPT algorithm [29]. Hence, the maximum power point is adapted to the PV conditions, while the converter output keeps up the voltage and the current levels according to the load requirements [13], [23], [29], [30]. This paper proposes a scheme where the MPPT algorithm is based on a dynamic hysteresis model.…”