Dynamic Modeling and Analysis of Buck Converter Based Solar PV Charge Controller for Improved MPPT Performance

Abstract

Maximum power point tracking (MPPT) control is a key functionality in solar photo-voltaic (PV) based power generation systems that enhances the efficacy of energy extraction. A pulse-width modulated (PWM) power converter connected to the PV is designed to perform this essential function. A variety of MPPT control schemes are available in literature, many of which are voltage based techniques wherein the PV bus voltage is controlled in closed loop to the required level that achieves MPP tracking. However, a suitable plant model of the PV fed converter system that facilitates the design of such a PV voltage control loop for MPPT purpose, is not fully covered in literature. In this paper, a small-signal model is developed for a buck converter based charger system fed by a PV source, which is a nonlinear active source. Based on this model, the relevant transferfunctions are analytically derived. The control to converter input voltage transfer-function vin/ d thus obtained, is useful in the systematic design of voltage controller bandwidth, that facilitates the selection of perturbation period of a typical perturb & observe (P&O) MPPT controller. Such an approach for control design is verified in this work on a PV system with energy storage, which is typically used in dual-mode or standalone PV applications. The P&O MPPT control is validated on a buck PV charge controller system employing a 36 V battery bank. Experiments conducted on a 1 kW hardware prototype verify the accuracy of the proposed analytical transfer-functions and the performance of the PV-charger system.

Reliability analysis of PV generating systems in the islanded DC microgrid under dynamic and transient operation

“…According to [45], it is necessary to consider the diffusion capacitance C d due to the forward‐biased semiconductor junction of the PV cells and the series inductance L s because of the meander‐type metalized bus‐bars in the series interconnection of many PV cells for studying the dynamic model of PV sources. The output current and voltage of the PV module can be rewritten as follows: $$\begin{equation}{i_{pv}} = {i_{ph}} - {v_d}\left( {\frac{1}{{{R_d}}} + \frac{1}{{{R_{sh}}}}} \right) - {C_d}\frac{{d{v_d}}}{{dt}}\end{equation}$$ $$\begin{equation}{v_{pv}} = {v_d} - {i_{pv}}{R_s} - {L_s}\frac{{d{i_{pv}}}}{{dt}}\end{equation}$$…”

Analysis and Comparison of Fuzzy Models and Observers for DC-DC Converters Applied to a Distillation Column Heating Actuator

“…The law of conservation of energy affirms that energy cannot be created or destroyed, it can only be changed from one form to another. Joule's Law expressed in Electric Power (P) is expressed in (9):…”

“…Regulating the inductor current i L and the capacitor voltage v C in the converter implies to regulate the output electrical power, Equation (9), that energies the electrical resistor in the heating actuator of the distillation, hence regulating the heating power, as presented in Equation ( 5), defines the distillation dynamics.…”

“…Different power converters models have been reported in the literature. Authors in [9] present a small-signal model for a single-stage PV fed Buck converter that acts as a battery charge-controller in order to improve its MPPT performance. In [10], a multi-physics model of Building-integrated photovoltaics (BIPV) integrated DC/DC converter is developed to quantify the potential of BIPV.…”

An Optimized PV based Plug-in Hybrid Electric Vehicle Charging Station Using Fuzzy-PI Controller Logic

“…Plug-in hybrid electrical vehicle with renewable energy resource is reviewed (ElNozahy & Salama, 2015). Buck converter with PV MPPT logic is presented in (Venkatramanan & John, 2019). MPPT-PV with double integral logic of grid system is presented in (Pradhan & Subudhi, 2016).…”