Photovoltaic inverter AC filter capacitor

What is a solar capacitor used for?

Capacitors play a critical role in the solar market. Among other uses, they are employed in PV inverters, which are devices that convert the DC power produced by solar cells into AC power that can be used in the electricity grid. Inverters typically make extensive use of large-sized capacitors that store electricity.

Why do inverter circuits need a capacitor?

New Bedford, MA 02744 January 12, 2015 Many of today’s inverter circuits require highly reliable and rugged capacitors to filter out the rich harmonic content of their AC output waveforms. The current of the harmonics at the output of inverter circuits is often greater than the current at the fundamental frequency.

What is a solar inverter system?

A solar inverter system converts the DC current from solar panels into AC power that can be used by the electrical grid. Its basic function is to switch the DC current on and off to provide the fundamental power line frequency (50 or 60 Hz depending on the location). Sophisticated electronics, including microcontrollers, improve the purity of the AC signal presented to the grid.

Are off-grid PV inverters a good option?

Off-grid PV inverters represent a good power source in remote areas without the availability of a power grid. They may not be subject to utility codes and power quality standards, as there is no power grid to feed into. However, the function or efficiency of the solar panel could be impacted and its lifetime may suffer.

How should a filter capacitor be designed?

The filter capacitors selected should be designed to minimize losses in order to be able to dissipate the increased power generated by the harmonic currents. The increased peak voltage, caused by harmonic voltages superimposed on the fundamental waveform, should be examined as part of the design process.

How does a Var inverter work?

The output inductor and capacitor form a low-pass filter that filters out the switching frequency. As the inverter is connected to the grid, the capacitance determines the VAR power exchange when the inverter is not operating and is kept small, typically < 5% rated power.