Review and comparison of methods for limiting leakage currents in single-phase transformerless PV inverter topologies

Transformerless inverters are widely used in different photovoltaic nonisolated ac module applications, mainly grid-tied (PV) generation systems, due to the benefits of achieving high efficiency over a wide load range, and low cost. Various transformerless inverter topologies have been proposed meet safety requirement ground leakage currents, such as specified VDE-4105 standard low-output ac-current distortion. Topology modifications full bridge designed balance maintain constant common mode output voltage, thereby eliminating or reducing currents. This article reviews compares methods for limiting currents known full-bridge inverters, as: H4, H5, H6, HERIC, their improvements. The main strategies reduce current schemes summarized, highlighting advantages disadvantages establishing points comparison with similar topologies. To compare properties medium power PV were implemented using IGBTs tested same components, simulation parameters PSPICE evaluate performance terms energy characteristics. detailed stage operating principles, extended PWM modulator, integrated universal gate driver galvanic isolation transmission path control signal all inverter, well isolated floating bias supply drivers described.