Highly efficient transformerless solar inverter topologies

Grid connected photovoltaic energy systems (PVES) are semiconductor based, and since they yield direct voltage/current they need inverters as an interface to the grid. Especially between 1–20 kW, with the reduction in the cost and size, single phase transformerless PVES inverters become widely used. In this paper, these widespread transformerless PVES inverters are investigated. In the work, transformerless PVES inverters will be introduced and common mode current which is one of the most important differences of these inverters from traditional inverters with transformer and bears restrictions on the usage of transformerless inverters will be emphasized. The work will be supported by simulations.

[1]  U. Borup,et al.  Transformerless Photovoltaic Inverters Connected to the Grid , 2007, APEC 07 - Twenty-Second Annual IEEE Applied Power Electronics Conference and Exposition.

[2]  Remus Teodorescu,et al.  Leakage current evaluation of a singlephase transformerless PV inverter connected to the grid , 2007, APEC 07 - Twenty-Second Annual IEEE Applied Power Electronics Conference and Exposition.

[3]  G. Franceschini,et al.  Unipolar PWM for transformerless grid-connected converters in photovoltaic plants , 2009, 2009 International Conference on Clean Electrical Power.

[4]  Peter Zacharias,et al.  Highly Efficient Single-Phase Transformerless Inverters for Grid-Connected Photovoltaic Systems , 2010, IEEE Transactions on Industrial Electronics.

[5]  Marco Liserre,et al.  The high efficiency transformer-less PV inverter topologies derived from NPC topology , 2009, 2009 13th European Conference on Power Electronics and Applications.

[6]  Tore Undeland,et al.  Power Electronics: Converters, Applications and Design , 1989 .