Hybrid power electronic controller for combined operation of constant power and maximum power point tracking for single‐phase grid‐tied photovoltaic systems

Abstract

This study presents a hybrid technique that offers constant power operation for single-phase grid-tied photovoltaic (PV) systems while performing maximum power point tracking function. A boost converter and a line commutated inverter (LCI) have been used for interfacing PV array with utility grid. Fixed firing angle of the LCI keeps the dc-link voltage constant and the boost converter extracts maximum power from the solar PV array by simply adjusting the duty ratio of the boost converter. A lowcapacity battery bank connected at the dc link is used to deliver constant power to grid. Harmonic filter is eliminated as the system inherently delivers quality supply with reduced current harmonics. PIC microcontrollers have been programmed for generating pulses to the inverter and the boost converter. The system has been simulated in MATLAB/Simulink and the simulation results are presented. The parameters of a PV panel rated for 100 W, 21.5 V and 6.83 A have been used for the simulation. Experiments have been conducted on the 21.5 V, 6.83 A PV panel for obtaining a constant power of 80 W with varying irradiation and the results correlate with the simulation study. Nomenclature L dc , R dc dc-link inductance (mH) and internal resistance (Ω) L crit critical value of dc-link inductance (mH) V oc , I sc open circuit voltage (V), and short circuit current (A) of the PV panel, respectively V pv , I pv output voltage (V) and current (A) of the PV panel on load, respectively P pv output power (W) of the PV panel on load (W) V dc , I dc dc bus voltage (equal to battery voltage) (V) and dc-link current (A), respectively I bc boost converter output current (A) I batt charging/discharging current through battery (A) I ch charging current supplied by the charger (A) V av average voltage at the dc link (V)

Photovoltaic MPPT Techniques Comparative Review

“…However in both fractional methods the MPP is never truly reached, as it is an approximation so it would always be close to MPP. In [44], a hybrid technique has been proposed by combining a current base P&O algorithm and an adaptive step size. This produced a fast settling time of max power point and reduced oscillations at the MPP due to adaptive step size of duty ratio.…”

Enhanced momentum LMS‐based control technique for grid‐tied solar system

“…Two types of converters are used in the grid‐connected PV system, (i) DC–DC boost converter is used to tracking the peak power from PV array and (ii) AC–DC converter is used to producing the sinusoidal synchronising signal to interface the PV panel into the grid. Substantial literatures [7–9] are available on grid‐interfaced PV systems and various publications [10] are reported on different types of control algorithms to control the grid injection power and the grid currents quality. The prime motives of the control algorithm are harmonics mitigation, load compensation with several characteristics such as fast extraction of load current fundamental component with noiseless filtering.…”

Integration of solar photovoltaic with battery to single‐phase grid

“…Grid‐connected SPV system with two power processing stages injecting a constant power to the grid while extracting maximum power from the SPV array is presented in [13]. The system performing power levelling with flawless coordinated control postures advantage over the existing two stage topologies.…”