TY - JOUR

T1 - Eliminating Ground Current in a Transformerless Photovoltaic Application

A1 - Lopez,Ocar

A1 - Freijedo,Francisco D.

A1 - Yepes,Alejandro G.

A1 - Fernandez-Comesana,Pablo

A1 - Malvar,Jano

A1 - Teodorescu,Remus

A1 - Doval-Gandoy,Jesus

AU - Lopez,Ocar

AU - Freijedo,Francisco D.

AU - Yepes,Alejandro G.

AU - Fernandez-Comesana,Pablo

AU - Malvar,Jano

AU - Teodorescu,Remus

AU - Doval-Gandoy,Jesus

PB - I E E E

PY - 2010/3

Y1 - 2010/3

N2 - For low-power grid-connected applications, a singlephase converter can be used. In photovoltaic (PV) applications, it is possible to remove the transformer in the inverter to reduce losses, costs, and size. Galvanic connection of the grid and the dc sources in transformerless systems can introduce additional ground currents due to the ground parasitic capacitance. These currents increase conducted and radiated electromagnetic emissions, harmonics injected in the utility grid, and losses. Amplitude and spectrum of the ground current depend on the converter topology, the switching strategy, and the resonant circuit formed by the ground capacitance, the converter, the ac filter, and the grid. In this paper, the ground current in a 1.5-kW PV installation is measured under different conditions and used to build a simulation model. The installation includes a string of 16 PV panel, a full-bridge inverter, and an LCL filter. This model allows the study of the influence of the harmonics injected by the inverter on the ground current.

AB - For low-power grid-connected applications, a singlephase converter can be used. In photovoltaic (PV) applications, it is possible to remove the transformer in the inverter to reduce losses, costs, and size. Galvanic connection of the grid and the dc sources in transformerless systems can introduce additional ground currents due to the ground parasitic capacitance. These currents increase conducted and radiated electromagnetic emissions, harmonics injected in the utility grid, and losses. Amplitude and spectrum of the ground current depend on the converter topology, the switching strategy, and the resonant circuit formed by the ground capacitance, the converter, the ac filter, and the grid. In this paper, the ground current in a 1.5-kW PV installation is measured under different conditions and used to build a simulation model. The installation includes a string of 16 PV panel, a full-bridge inverter, and an LCL filter. This model allows the study of the influence of the harmonics injected by the inverter on the ground current.

KW - Ground current

KW - Photovoltaic (PV) power systems

KW - Pulsewidth-modulated inverters

KW - Single-phase system

KW - Utility interface

U2 - 10.1109/TEC.2009.2037810

DO - 10.1109/TEC.2009.2037810

JO - I E E E Transactions on Energy Conversion

JF - I E E E Transactions on Energy Conversion

SN - 0885-8969

IS - 1

VL - 25

SP - 140

EP - 147

ER -