Single-phase transformerless inverters are broadly studied in literature for residential-scale\nPV applications due to their great advantages in reducing system weight, cost and elevating\nsystem efficiency. The design of transformerless inverters is based on the galvanic isolation\nmethod to eliminate the generation of leakage current. Unfortunately, the use of the galvanic\nisolation method alone cannot achieve constant common mode voltage (CMV). Therefore, a complete\nelimination of leakage current cannot be achieved. In addition, modulation techniques of single-phase\ntransformerless inverters are designed for the application of the unity power factor. Indeed,\nnext-generation PV systems are required to support reactive power to enable connectivity to the\nutility grid. In this paper, a proposed single-phase transformerless inverter is modified with the\nclamping method to achieve constant CMV during all inverter operating modes. Furthermore,\nthe modulation technique is modified by creating a new current path in the negative power region.\nAs a result, a bidirectional current path is created in the negative power region to achieve reactive\npower generation. The simulation results show that the CMV is completely clamped at half the DC\nlink voltage and the leakage current is almost completely eliminated. Furthermore, a reactive power\ngeneration is achieved with the modified modulation techniques. Additionally, the total harmonic\ndistortion (THD) of the grid current with the conventional and a modified modulation technique is\nanalyzed. The efficiency of the system is enhanced by using wide-bandgap (WBG) switching devices\nsuch as SiC MOSFET. It is observed that the efficiency of the system decreased with reactive power\ngeneration due to the bidirectional current path, which leads to increasing conduction losses.
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