Design of a single stage grid-connected buck-boost photovoltaic inverter for residential application

Design and analysis of hybrid solar-wind energy system using CUK & SEPIC converters for grid connected inverter application

“…The output voltage of a grid-tie inverter should maintain some fixed requirements so that it can provide power to utility grid [1], [12]. The requirements are given below:…”

“…SPWM signal is generated from sampled sine wave. Thus the frequency of the grid and the output from the GTI will be same where this is one of the most significant requirements for the GTI [1], [12]. The sine wave is rectified with a precision rectifier after sampling and an additional high frequency triangle wave of 20 KHz frequency is used.…”

A Family of Single-Stage, Buck-Boost Inverters for Photovoltaic Applications

“…Thus, a number of buck-boost type single-stage inverters with low component counts were reported. For instance, single-stage buck-boost inverters with only three switches were proposed in [4,5], as shown in Figure 1a, where a tapped inductor was 2 of 21 used as a regular inductor in one half-line cycle and as a fly-back transformer in the subsequent half-line cycle. Unfortunately, this type of inverter cannot attain the required voltage step-up.…”

“…Doing so significantly increases the total number of switches (i.e., eight). Although the ideas of [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] are very interesting, their attained voltage gain is comparable to the traditional buck-boost converter.…”

“…(e) (f) Figure 1. Prior-art, single-stage, buck-boost inverters: (a) [5], (b) [6], (c) [7], (d) [12], (e) [15], and (f) [20].…”