A New Converter for Non-Isolated PV Systems

Abstract

A new converter for the non-isolated PV (photovoltaic) system is presented in this paper. It has the advantage that the input terminal of the proposed converter is connected to the output negative terminal. In this way, the parasitic capacitance is bypassed to eliminate the undesirable leakage current. The proposed converter can achieve the step-up voltage with four switches only. Aside from that, the carried-based modulation is used, and the control structure is simple. The article analyzes the working modes and control strategy of the proposed converter. In addition, a comparative analysis is provided. The feasibility of the proposed converter under different working modes is verified by simulation. Finally, the digital control prototype with DSP plus FPGA is established and the experimental tests are carried out. The experimental results verify the effectiveness of the proposed converter.

A Novel Single-Stage Common-Ground Transformerless Buck–Boost Inverter

“…To show the potential capability of the proposed CGBBI topology, a comparative analysis between the proposed CGBBI topology and other common-ground transformerless inverters is presented in Table 1. It can be seen that the number of devices in the inverters proposed by [21,23] is lower than that of the inverters developed by [22,24,25], as well as the proposed CGBBI of this study. Moreover, the total number of devices in the proposed CGBBI is lower than that of the inverter in [22,24].…”

“…Moreover, the total number of devices in the proposed CGBBI is lower than that of the inverter in [22,24]. Having considered voltage stress across the power switches, the inverter developed by [22] and our proposed CGBBI have total switch voltage stress of 2V in + 4V o , which is lower than that of the inverter in [21,[23][24][25]. As is clear from Table 1, the number of high-frequency switches in each period in the proposed CGBBI topology is the least when compared with other inverters.…”

“…Compared with two-stage configurations, single-stage configurations have more benefits, including compactness, lower device count, lower costs, and greater efficiency [16]. From this point of view, single-stage inverters are reported in the literature, and their comprehensive review is given in [17][18][19][20][21][22][23][24][25][26][27]. Common-ground transformerless inverter topologies were introduced in [21][22][23][24][25][28][29][30], which directly connect the ground of the grid to the negative of the DC input source.…”

“…From this point of view, single-stage inverters are reported in the literature, and their comprehensive review is given in [17][18][19][20][21][22][23][24][25][26][27]. Common-ground transformerless inverter topologies were introduced in [21][22][23][24][25][28][29][30], which directly connect the ground of the grid to the negative of the DC input source. The common-mode voltage is equal to zero, and it also protects against any high-frequency content.…”

Grid-Connected and Isolated Renewable Energy Systems

“…The proposed synchronization technique is improved in terms of the steady and transient performance. In the fourth paper [4], entitled "A New Converter for Non-Isolated PV Systems", the authors propose a new converter for the non-isolated photovoltaic system. It is able to achieve the step-up voltage with four switches only.…”