Photovoltaic inverter isolation transformer

What is galvanic isolation in transformerless PV inverter?

In transformerless PV inverter, the galvanic connection between the PV arrays and the grid allows leakage current to flow. The galvanic isolation can basically be categorized into DC decoupling and AC decoupling methods.

How do photovoltaic inverters work?

In the particular case of grid-connected photovoltaic inverters, most of the power converter topologies use a transformer operating at low or at high frequency, which provides galvanic isolation between photovoltaic panels and electrical grid. Low frequency transformers are big, heavy and expensive, and introduce additional losses in the system.

How is a power transformer isolated?

Isolation between the input and output is provided by the insulation layers between the primary coil and the secondary coil. For efficient power transfer across isolation, a self oscillating high frequency oscillator is used to drive the primary for the power transformer, and high frequency Schottky diodes are used to provide rectified dc voltage.

Why do PV inverters need a transformer?

Galvanic isolation is provided and the safety is assured with the use of transformer. Because of the high cost and high loss of the transformer, the PV inverter becomes expensive and low efficient.

Do PV circuits need an isolation transformer?

However, inclusion of the isolation transformer brings extra power loss and accounts for further board space, which means more cost. The isolation requirements of the PV circuits and grid-tied circuits need to be considered separately for this case.

What is microtransformer based isolation integration?

Microtransformer based isolation integration is the ideal solution for the isolation needs for grid-tied PV inverters, central inverters, or microinverters.