Dual input step-up inverter with low leakage current for PV generation applications

The non-isolated inverter has been widely used in photovoltaic generation applications due to its low cost, reduced size, low weight, and high efficiency. However, when there is no galvanic isolation between the photovoltaic (PV) plant and the grid, leakage current may be generated due to the parasitic capacitor to the ground of the photovoltaic (PV) plant, which brings electromagnetic interference (EMI) and security problems. The main idea of this article is to construct a step-up voltage source inverter with two low-voltage input sources. The proposed inverter integrates a step-up dc–dc converter and a modified step-up dc–dc converter that has the advantages of a simple structure and strong voltage boosting capability. Moreover, the negative polarity of a solar cell and the neutral point of a power grid are linked together, which can greatly reduce the leakage current and improve the reliability and efficiency of the PV system. The operating principle, modulation strategy, and static behavior of the proposed inverter are described in detail. To verify the effectiveness of the proposed structure, a 250w laboratory test setup is established, and test results have been shown.