Inverter dedicated to thin-film photovoltaic modules

What is a thin-film module – building integrated PV (BIPV)?

Thin-film modules are particularly popular in BIPV – Building Integrated PV. They are often preferred due to their uniform appearance, and additionally these installations are far more frequently affected by shading. In particular, vertical surfaces are generally affected by shading to a greater extent, e.g. by neighboring buildings and canopies.

How insulated is a PV plant?

The most cells in a PV plant lay permanently on a non-zero potential. Since large leakage currents are to be avoided for personnel and fire protection reasons, the PV modules must be well insulated. To put it another way: the insulation resistance Riso must not exceed a certain value.

How many m2 should a PV inverter have?

2 m2 in contrast only a minimum of 20 M Ω . For PV plants without galvanic isolation (transformerless), the Riso must be at least 2 000 kΩ per kW input power of the inverter. Adherence to this limiting value must be monitored by the inverter.

What is the potential of a PV module?

The potential (voltage against ground) of the PV cells here is between − 200 V and − 350 V depending on the length of the string and the on the device type of the inverter used. The frame of the PV modules have, however, a potential of 0 V, since it must be grounded for safety reasons.

What voltage does a PV module have?

This phenomenon occurs most commonly in the PV module that is closest to the negative pole. The potential (voltage against ground) of the PV cells here is between − 200 V and − 350 V depending on the length of the string and the on the device type of the inverter used.

How does a transformerless inverter work?

For many transformerless inverters this amounts to half of the alternating voltage (115 V / 50 Hz). The fluctuating voltage constantly changes the state of charge of the parasitic PV capacitor and causes a displacement current that is proportional to the capacitance and to the voltage amplitude.