An efficient switched inductor–capacitor‐based novel non‐isolated high gain SEPIC for solar energy applications

Abstract

The solar photovoltaic (PV) sources have low voltage output and hence cannot be used directly in micro‐grid applications. Therefore, to boost the low voltage output, a novel high gain single‐ended primary inductor converter (SEPIC) is proposed in this manuscript. The proposed high gain SEPIC (HGS) has an advantage of obtaining high voltage gain at a low duty ratio and continuous input current, which makes it viable for PV applications. The proposed converter offers simple control, and the high gain is obtained without the use of any transformer or coupled inductor so the semiconductor switch will not experience a voltage overshoot during the turn‐off operation. Hence, the conduction losses of the converter switch are reduced, and the performance of the converter is enhanced. Additionally, this manuscript also investigates the effectiveness of the proposed HGS in integration with the PV array. An extensive performance evaluation of the proposed HGS is investigated and compared with different SEPIC topologies in irradiance change conditions. Experimental implementation of the proposed HGS confirms the theoretical analysis and verifies the performance. Also, the real time (RT) analysis of the proposed HGS with PV array is conducted to show the validation of high gain operation for the PV application.

Modeling and design of a photovoltaic‐fed single‐ended primary‐inductor converter for maximum power point tracking with current mode control

“…The small-signal transfer functions defining the relationship between the system state variables considered as outputs and the duty-cycle (input) are defined according to the following expressions: Applying the Laplace transform to the small-signal expressions of the duty cycle for the four models ( 23), (24)(25)(26), and substituting the obtained result corresponding to each model in (34), one arrives to the following low-frequency small-signal control law under PCMC:…”

“…, where b d is substituted by its expression from the previous small-signal control law for each model (23)(24)(25)(26). Thus, the controlto-output transfer function ( b i ref À to Àb v pv ) for the inner current loop is given for the four models by the following expression:…”

“…The particular topology of the SEPIC allows to step up or to step down the voltage at its output by means of adjusting the duty cycle of the square wave signal driving the converter main switch thus offering a significant compliance at any voltage level 26 and being able to sweep the entire curve of a PV source.…”

“…This requirement is fulfilled in the SEPIC converter because of the existence of an inductor at its input port while the input current of a ZETA converter is pulsating, which can cause the reduction of the lifespan of PV arrays. 25 The particular topology of the SEPIC allows to step up or to step down the voltage at its output by means of adjusting the duty cycle of the square wave signal driving the converter main switch thus offering a significant compliance at any voltage level 26 and being able to sweep the entire i À v curve of a PV source.…”

Switched inductor‐capacitor‐based quasi‐Z source converter for renewable energy source integration

“…Modified boost converters using SL, SC, VM, etc., are reported in literature to increase the gain of conventional boost converters. [9][10][11] A two-inductor boost converter with VM and SC cells is reported to increase the voltage gain in Andrade et al 9 A family of high-gain modified boost converter is reported in Shaw et al 11 In all these converters, even though the gain is increased compared to the conventional boost converters, there is still a limitation on the maximum voltage gain. To overcome this limitation, quadratic gain and modified quadratic gain converters are introduced.…”