Title :
High efficiency transformerless PV power converters
Author :
Poliseno, M.C. ; Mastromauro, R.A. ; Liserre, M. ; Dell´Aquila, A.
Author_Institution :
Dept. of Electr. & Electron. Eng., Politec. of Bari, Bari, Italy
Abstract :
Transformer-less photovoltaic (PV) inverters offer better efficiency compared to inverters connected to the grid through a transformer providing galvanic isolation. However, in case the transformer is omitted, the generated common-mode voltage greatly influences the leakage current flowing to ground through the parasitic capacitance of the PV array. Hence, both the power stage and the modulation strategy of the converter, shall be properly designed to avoid leakage current while guaranteeing high efficiency and reactive power handling capability that are requested by national grid codes. In this paper, three single phase transformer-less inverter topologies are analyzed: the Highly Efficient and Reliable Inverter Concept converter (HERIC), a recently published topology based on a combination of step-down converters and a recently patented modification of the Neutral Point Clamped converter (NPC) optimized for MOSFET use. Simulation results are used to show: current waveform, reactive power handling capability, efficiency and produced common-mode voltage.
Keywords :
MOSFET; invertors; leakage currents; photovoltaic power systems; power grids; reactive power; HERIC; MOSFET; NPC; PV array; PV inverters; common-mode voltage; converter modulation strategy; current waveform; galvanic isolation; high efficiency transformerless PV power converters; highly efficient and reliable inverter concept converter; leakage current; national grid codes; neutral point clamped converter; parasitic capacitance; reactive power; single phase transformerless inverter topology; step-down converters; transformerless photovoltaic inverters; Arrays; Inverters; Leakage current; MOSFET circuits; Reactive power; Switches; Topology; common-mode voltage; efficiency; leakage current; photovoltaic transformer-less inverter;
Conference_Titel :
Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2012 International Symposium on
Conference_Location :
Sorrento
Print_ISBN :
978-1-4673-1299-8
DOI :
10.1109/SPEEDAM.2012.6264526